LIBRARY 
 
 THE UNIVERSITY 
 OF CALIFORNIA 
 
 SANTA BARBARA 
 
 PRESENTED BY 
 
 Douglas Warner
 
 Boobs bp -Benjamin EanU 
 
 ECONOMIC HISTORY SINCE 1763. Cambridge, 1889; 
 5th ed., New York, 1911. 
 
 SELECT BIBLIOGRAPHY OF ECONOMICS. Cam- 
 bridge, 1895. 
 
 LIFE, UNPUBLISHED LETTERS AND PHILO- 
 SOPHICAL REGIMEN OF THE THIRD EARL OF 
 SHAFTESBURY. London, 1900. 
 
 BIBLIOGRAPHY OF PHILOSOPHY. Two vols. New 
 York, 1905. 
 
 MODERN CLASSICAL PHILOSOPHERS Boston, 
 1907. 
 
 THE CLASSICAL MORALISTS. Boston, 1909. 
 THE CLASSICAL PSYCHOLOGISTS. Boston, ign.
 
 THE CLASSICAL PSYCHOLOGISTS
 
 THE CLASSICAL 
 
 PSYCHOLOGISTS 
 
 SELECTIONS 
 
 ILLUSTRATING PSYCHOLOGY 
 FROM ANAXAGORAS TO WUNDT 
 
 COMPILED BY 
 
 BENJAMIN RAND, PH.D. 
 
 HARVARD UNIVERSITY 
 
 BOSTON NEW YORK CHICAGO 
 HOUGHTON MIFFLIN COMPANY 
 
 Rtocrisi&e press Cambribgc
 
 COPYRIGHT, 1912, BY BENJAMIN RAND 
 ALL RIGHTS RESERVED
 
 LIBRARY 
 UNIVERSITY OF CALIFORNIA 
 
 SANTA BARliAilA 
 
 PREFACE 
 
 "THE CLASSICAL PSYCHOLOGISTS" is a companion volume 
 in the field of psychology to the author's " The Classical Moral- 
 ists" in the sphere of ethics, and also to his " Modern Classical 
 Philosophers "in the domain of philosophy. Its aim is to pre- 
 sent in a series of selections some of the most essential features 
 of the psychological doctrines which have appeared from Anax- 
 agoras to Wundt. The book is thus virtually a history of psy- 
 chology, not derived from an ordinary description of systems, 
 but based upon extracts from original sources and upon trans- 
 lations of the authors themselves. Such a work, it is hoped, may 
 prove adapted for colleges and universities as a text-book of 
 reading accompanying courses of lectures in general psychology, 
 and may become a necessary requirement of study made of all 
 students before entering upon the study of the special divisions 
 of existing psychology. The general reader, moreover, will find 
 it an interesting volume of original material of the great 
 psychologists from the earliest to the most recent times. 
 
 From Aristotle's u De Anima " there is reproduced at the 
 outset the first extant history of psychological theories. With 
 the name of Anaxagoras, who emphasizes the Nous as present 
 in all things, but with insight as to its different forms in mind 
 and matter, it was thought the work might fittingly begin. Em- 
 pedocles is mentioned, who maintains that like is known by 
 like, and that perception is due to elements in us coming in 
 contact with similar elements outside. Democritus is also in- 
 cluded, who believes the soul to consist of atoms, the peculiar 
 fineness, smoothness, and mobility of which cause perception 
 and thought. The second selection is taken from the Theaetetus 
 of Plato, which Professor Jowett describes as the oldest work 
 in psychology that has come down to us, and which here con- 
 tains the contending Sophistic and Socratic views on the nature
 
 vi PREFACE 
 
 of perception. In it Protagoras affirms that the individual man 
 is the measure of all things, whereas Socrates seeks to conduct 
 Theaetetus by means of the dialogue to the acceptance of a 
 universally valid knowledge. Although Plato's psychological 
 views are scattered through various dialogues, the Republic 
 best contains his treatment of the fundamental problem of the 
 relation of soul and body. There is consequently printed from 
 it, his presentation of the three faculties of the soul, of the 
 correlation of the faculties, and of the soul's immortality. In 
 Aristotle we have the greatest psychologist of the ancient 
 world, and the one who first treated psychology as a separate 
 science. To the introductory account of earlier theories by him, 
 with which this work began, is here added a description from 
 the " De Anima" of his own doctrines. His conceptions of the 
 essence of the soul, and its relation to the body as form to mat- 
 ter, of the various activities of the five senses and the common 
 sense, and of the functions of sensation, imagination, and 
 thought, are given in full, as their importance demands. From 
 Diogenes Laertius' " Lives and Opinions of Eminent Philoso- 
 phers" is drawn the psychology of the Stoics, in which the ani- 
 mating principle of the soul is described as a warm breath 
 within us, with a resultant trichotomy of body, soul and 
 spirit. From Diogenes Laertius is likewise taken the Epicurean 
 psychology, in which the soul is conceived to be a bodily sub- 
 stance composed of exceedingly fine atoms, which are allied in 
 nature to air and fire, and are diffused throughout the whole 
 body. Lucretius in the didactic poem on "The Nature of 
 Things," whereby Hellenistic thought was transferred to Rome, 
 follows next with a description, like that of Epicurus, of sen- 
 sation as everywhere occurring in the body; but he regards the 
 mind as the directing principle "holding the fastnesses of life. " 
 From the "Enneades" of Plotinus, who was the most eminent 
 of the Neoplatonists, is reproduced the theory of emanation, in 
 which the soul is deemed the image and product of the Nous, 
 just as the Nous is of the One. 
 
 In the mediaeval period, Tertullian, one of the greatest of the 
 early Christian fathers, sets forth in the extracts presented from
 
 PREFACE vii 
 
 his "Treatise on the Soul," the corporeal nature of the soul, its 
 simplicity, its source in the breath of God, its rationality, and 
 its immortality. Gregory of Nyssa, who wrote in the latter part 
 of the fourth century, here argues in the " Endowment of Man," 
 that the intellect pervades all parts of the body alike, but has 
 in itself a divine beauty, since it is created in the image of 
 the most beautiful. Augustine, in whom the Patristic period 
 reached its culmination, emphasizes in his work "On the 
 Trinity," self-consciousness as the distinguishing characteristic 
 of the mind arising from its immateriality, and regards memory, 
 understanding, and particularly will, as its most important fac- 
 ulties. Thomas Aquinas, who represents scholasticism in its 
 full development, returns in the "Summa Theologica" to the 
 Aristotelian doctrine of the rational soul as the essential form 
 of the body, and contends as against Augustine for the superi- 
 ority of reason to will. 
 
 The modern period is introduced with chapters from Thomas 
 Hobbes' "Human Nature," in which the founder of empirical 
 psychology reduces all mental processes to motions. An ample 
 presentation is given of Descartes' "The Passions of the Soul," 
 of which Professor David Irons says that "it would be difficult 
 indeed to find any treatment of the emotions much superior to it 
 in originality, thoroughness, and suggestiveness." Spinoza, who 
 teaches in " The Ethics" that the soul and body are not two 
 distinct substances, but that thought and extension are two of 
 the many attributes of the one real being, seeks to prove by 
 the mathematical method in the part reproduced, that the 
 order and connection of ideas are identical with the order and 
 connection of things. From Leibnitz' "Philosophical Works" 
 selections have been made in which he presents his theory of 
 monads, and likewise illustrates the interaction of soul and 
 body after the manner of two clocks so constructed as to run 
 in perfect harmony. Christian Wolff, whose name is chiefly 
 associated with the faculty psychology, designates in those 
 sections of the " Rational Psychology" here chosen, the vis 
 repraesentiva as the fundamental force and sufficient ground 
 for everything that takes place in the soul.
 
 viii PREFACE 
 
 English empirical psychology is next traced through Locke, 
 Berkeley, and Hume. From Locke's "Essay on the Human 
 Understanding" there is given, as Locke believes, " the true 
 history of the beginning of human knowledge," wherein all our 
 ideas are derived from sensation and reflection. Berkeley's 
 "Essay towards a new Theory of Vision" is reproduced with 
 desirable fullness, as it contains his noted research into the differ- 
 ence between the ideas of sight and touch, wherein he draws 
 the striking inference that the visible world is a visible lan- 
 guage, which we learn to translate into the tactual experience 
 that the visible phenomena naturally signify. Hume in the 
 chapters from the " Treatise of Human Nature" would resolve 
 all perceptions of the human mind into "impressions" and 
 "ideas," differing only in force and liveliness, and also would 
 derive our conception of necessary connection solely from the 
 experience of the constant association of certain objects. 
 Hartley was the chief precursor of English associational psy- 
 chology, although preceded as he confesses by the modest Gay, 
 and from the "Observations on Man" are reprinted his two 
 principal doctrines of vibrations, and of association. 
 
 Charles Bonnet, the Swiss, and an early founder of physiolo- 
 gical psychology, in the "Analytical Essay upon the Faculties 
 of the Soul" of which his own "Abstract" has been in part 
 translated, lays stress throughout on the dependence of psychical 
 phenomena upon physical conditions, and considers the divers- 
 ity of mental perceptions as really due to the different struc- 
 tures of the various sensory fibres. The French psychologist 
 Condillac, in the chapters from the "Treatise of Sensations," 
 views all psychical functions as transformations of sensations, 
 and graphically illustrates his theory by the endowment of a 
 marble statue with the different senses of man in succession. 
 From Reid, founder of the Scotch School of common sense, 
 those portions of the "Essays on the Intellectual Powers of 
 Man" are given in which he analyzes the fundamental acts of 
 sensation and perception, contending that the former is confined 
 to the soul, but that the latter implies a belief in the existence of 
 an external world. Brown's eloquent "Lectures on the Philo-
 
 PREFACE ix 
 
 sophy of the Human Mind," published after his death, contains 
 a most subtle and brilliant analysis of muscular sensations, 
 the inclusion of which, it is believed, must add substantial 
 value to the pages of this work. 
 
 With Herbart's " Textbook of Psychology" begins scientific 
 psychological research, in which from the intensive relations of 
 ideas and the laws of their change it is sought to derive the pos- 
 sibility and necessity of applying mathematics to psychology. 
 In Beneke's " Textbook of Psychology as Natural Science" a 
 profound German psychologist seeks to reduce all psychical 
 phenomena to four " fundamental processes." Drobisch, who 
 may be regarded as one of the distinguished representatives of 
 mathematical psychology, presents in his " Empirical Psychol- 
 ogy," the dynamics of ideas as the fundamental principle of ex- 
 planation of psychical phenomena. Maine de Biran, whom 
 Cousin thought the first metaphysician of the nineteenth cent- 
 ury, has written some most instructive chapters in his " Essay 
 upon the Foundations of Psychology," wherein he treats of 
 voluntary effort as the primordial fact of our psychical life, 
 analyzing it into the two distinct but inseparable elements of 
 will and resistance of our own body, from which he derives the 
 beginning of personality. 
 
 The revival of English associational psychology is to be 
 found in the chapters, taken from James Mill's "Analysis of the 
 Phenomena of the Human Mind"; but its fullest fruition ap- 
 pears in the laws of association reproduced at considerable 
 length from Bain's " The Senses and the Intellect." The cardi- 
 nal feature of Spencer's " Principles of Psychology " is here pre- 
 sented in the evolution of mind " from an indefinite incoherent 
 homogeneity to a definite coherent heterogeneity." The selec- 
 tion from Johannes Mueller's "Elements of Physiology" will 
 render more accessible his very important account of the gen- 
 eral laws of sensation. A fitting place is naturally given also to 
 Lotze's theory of " local signs" as embodied in his " Outlines of 
 Psychology." 
 
 In more recent psychology, translations from Weber's a The 
 Sense of Touch and the Common Feeling" of his well known
 
 x PREFACE 
 
 Law, and from Fechner's " Elements of Psychophysics " of his 
 " Measurement of Sensation," are indispensable contributions in 
 the domain of psy chophysics, being the experiments of the former, 
 well described by Professor E. B. Titchener, as "the founda- 
 tion stone of experimental psychology," and the interpretation 
 of the latter as the erection in large measure of " a whole build- 
 ing." The Young-Helmholtz theory of color vision has been 
 translated from Helmholtz's " Manual of Physiological Optics, " 
 which is regarded as the most important work that has yet ap- 
 peared on the physiology and physics of vision. " The Funda- 
 mental Principles of a Theory of Light Sensation" by Hering 
 will serve also to supplement those of Helmholtz, as a necessary 
 foundation for the study of the more recent valuable contribu- 
 tions which have been made to this subject. From Mach's 
 " Analysis of Sensations" is reproduced his theory of space per- 
 ception, preceded by an account of the self intuition of the ego, 
 which " every student of psychology should know." Stumpf's 
 " Tone Psychology" contains a theory of tonal fusion, written 
 by a recognised authority in this domain. The remarkable 
 chapter of William James entitled "The Stream of Conscious- 
 ness " is taken from his introductory " Psychology. " Then fol- 
 lows the James-Lange theory of emotions, in which a novel doc- 
 trine is set forth by both writers with unusual brilliancy of 
 style. Most characteristic and authoritative chapters from 
 Wundt's "Principles of Physiological Psychology" on the 
 problem of physiological psychology, and from his " Outlines of 
 Psychology" on volition and apperception, conclude the work. 
 The outline of the selections in the preceding paragraphs 
 traces the attempt, here made for the first time, to present his- 
 torically in a single volume original texts containing funda- 
 mental theories of the classical psychologists, alike in ancient, 
 mediaeval, and modern times. The study of psychology as pur- 
 sued to-day in several important divisions might suggest the 
 desirability of a work of recent material from these various do- 
 mains. An historical volume of the character of this book was, 
 however, deemed not only more in harmony with the other works 
 of the author's series, but also as much more necessary for the
 
 PREFACE xi 
 
 use of students before entering upon investigations in special 
 fields. Whilst a chronological order has been followed in gen- 
 eral, slight variations have made it possible to group psycho- 
 logists somewhat according to their schools, and the emphasis, 
 moreover, in the most recent period, has been placed on the 
 selection of those important laws and theories which have al- 
 ready taken on a classical importance. The selections have 
 been given with sufficient fullness, it is hoped, always to repro- 
 duce the author and subject in an intelligible and connected 
 way. Authorities will differ concerning the choice of authors 
 and subjects. In this matter important advice has been re- 
 ceived from the psychologists alike of Harvard University and 
 also of other large American Universities. Although such valu- 
 able opinion always has been carefully considered, the responsi- 
 bility for the final decision naturally rests upon the editor. 
 
 Thirteen authors appear in this work in selections trans- 
 lated for the first time into English. To my colleague Pro- 
 fessor Edward Kennard Rand, of the classical department of 
 Harvard University, I am indebted for the translation from the 
 Latin of "The essence and nature of the soul" contained in 
 Christian Wolff's " Rational Psychology"; and to Dr. Herbert 
 Sidney Langfeld of the Harvard Psychological Department for 
 the translation from the German of " The measurement of sen- 
 sation" in Gustav Fechner's ''Elements of Psychophysics." 
 The translations from the Greek of Gregory of Nyssa, from the 
 Latin of Thomas Aquinas, from the French of Charles Bonnet 
 and Maine de Biran, and from the German of Friedrich Ed- 
 uard Beneke, Moritz Wilhelm Drobisch, Ernst Heinrich 
 Weber, Heinrich von Helmholtz, Ewald Hering, Carl Stumpf, 
 and Carl Lange in the text of H. Kurella, have been made 
 by the author of this work. In French Professor Irving Babbitt 
 and Dr. C. J. Ducasse, and in German Prof. W. G. Howard and 
 Dr. J. Loewenberg of Harvard have made valuable suggestions. 
 My thanks for permission to reprint selections of various psy- 
 chologists are also due to the publishers and translators whose 
 names will be found at the beginning of the respective chapters 
 accompanying the titles of the works thus utilized. The book
 
 xii PREFACE 
 
 will best attain its desired aims if its representative selections 
 shall serve to inspire the perusal of the complete works of the 
 classical psychologists, and if it shall aid in any measure to 
 maintain the importance and prestige of classical psychology. 
 
 BENJAMIN RAND. 
 
 EMERSON HALL, HARVARD UNIVERSITY.
 
 CONTENTS 
 
 ANCIENT 
 
 I. ANAXAGORAS (500-428 B.C.), EMPEDOCLES 
 (490-430), DEMOCRITUS (460-370) 
 
 From ARISTOTLE'S DE ANIMA i-io 
 
 Translated from the Greek by R. D. Hicks. 
 
 BOOK I. CHAP. I. INTRODUCTION OF ARISTOTLE . . i 
 
 BOOK I. CHAP. II. EARLY PSYCHOLOGICAL THEORIES . 5 
 
 II. PROTAGORAS (480-411), SOCRATES (469-399) 
 
 From PLATO'S THEAETETUS 11-26 
 
 Translated from the Greek by Samuel Walters Dyde. 
 THE NATURE OF PERCEPTION II 
 
 III. PLATO (427-347) 
 
 THE REPUBLIC 27-44 
 
 Translated from the Greek by J. L. Dames and D. J. Vaughan. 
 
 BOOK IV. THE THREE FACULTIES OP THE SOUL. . . 27 
 
 BOOK VI. THE CORRELATION OF THE FACULTIES . . 36 
 
 BOOK X. THE SOUL'S IMMORTALITY 41 
 
 IV. ARISTOTLE (384-322) 
 
 PSYCHOLOGY 45-83 
 
 Translated from the Greek by William Alexander Hammond, 
 BOOK II. THE FACULTIES OF THE SOUL. 
 
 CHAP. I. The Definition of the Soul 45 
 
 CHAP. II. The Principle of Life 47 
 
 CHAP. III. The Various Meanings of the Soul ... 51 
 
 CHAP. IV. The Soul and Final Cause 52 
 
 CHAP. V. Sensation and Thought 56 
 
 CHAP. VI. Sense Qualities 59 
 
 BOOK III. SENSATION, IMAGINATION AND THOUGHT. 
 
 CHAP. I. The 'Common Sensibles' 60 
 
 CHAP. II. The 'Common Sense' 62 
 
 CHAP. III. Imagination 66 
 
 CHAP. IV. The Theory of Reason 70 
 
 CHAP. V. Active and Passive Reason 73 
 
 CHAP. VI. Thought and Truth 73 
 
 CHAP. VII. Thought and its Object 75 
 
 CHAP. VIII. Ideas and Images 77
 
 xiv CONTENTS 
 
 CHAP. IX. Reason and Desire 78 
 
 CHAP. X. Psychology and Conduct 80 
 
 CHAP. XI. The Moving Principle 82 
 
 V. ZENO (356-264) 
 
 From DIOGENES LAERTIUS' LIVES AND OPIN- 
 IONS OF EMINENT PHILOSOPHERS .... 84-88 
 Translated from the Greek by Charles D. Yonge. 
 BOOK VII. THE PSYCHOLOGY OF THE STOICS .... 84 
 
 VL EPICURUS (341-270) 
 
 From DIOGENES LAERTIUS' LIVES AND OPIN- 
 IONS OF EMINENT PHILOSOPHERS . . . 89-96 
 Translated from the Greek by Charles D. Yonge. 
 BOOK X. THE EPICUREAN PSYCHOLOGY 89 
 
 VH. TITUS LUCRETIUS CARUS (95-51) 
 
 ON THE NATURE OF THINGS 97-105 
 
 Translated from the Latin by H. A. J. Munro. 
 BOOK III. THE MIND 97 
 
 VIII. PLOTINUS (205 A.D.-270) 
 
 ENNEADES 106-115 
 
 Translated from the Greek by Thomas Taylor. 
 
 VII. THE SOUL 106 
 
 VIII-IX. THE INTELLECT 113 
 
 PATRISTIC AND MEDIAEVAL 
 
 IX. QUINTUS SEPTIMIUS FLORENS TERTUL- 
 LIANUS (160-220) 
 
 A TREATISE ON THE SOUL 116-124 
 
 Translated from the Latin by Peter Holmes. 
 
 CHAP. IV. THE SOUL CREATED 116 
 
 CHAP. V. THE SOUL'S CORPOREAL NATURE ... 117 
 
 CHAP. X. THE SOUL'S SIMPLICITY . 118 
 
 CHAP. XII. THE MIND AND THE SOUL 120 
 
 CHAP. XVI. THE SOUL'S RATIONALITY 122 
 
 CHAP. XXII. RECAPITULATION 123 
 
 X. GREGORY OF NYSSA (331-394) 
 
 THE ENDOWMENT OF MAN 125-131 
 
 Translated from the Greek by Benjamin Rand. 
 CHAP. XII. THE LOCATION OF THE INTELLECT ... 125
 
 CONTENTS xv 
 
 XI. SAINT AUGUSTINE (354-430) 
 
 ON THE TRINITY 132-13? 
 
 Translated from the Latin by Arthur West Haddan. 
 .BOOK X. CHAP. X. THE NATURE OF MIND .... 132 
 BOOK X. CHAP. XI. MEMORY, UNDERSTANDING, AND 
 WILL . 135 
 
 XII. THOMAS AQUINAS (1225-1274) 
 
 SUMMA THEOLOGICA 138-146 
 
 Translated from the Latin by Benjamin Rand. 
 QUESTION LXXVI. RATIONALITY THE ESSENTIAL FORM 
 
 IN MAN 138 
 
 QUESTION LXXVI. THE RELATION OF SOUL AND BODY 143 
 QUESTION LXXXII. THE SUPERIORITY OF REASON TO 
 WILL 145 
 
 MODERN 
 
 XIII. THOMAS HOBBES (1588-1679) 
 
 HUMAN NATURE 147-167 
 
 CHAP. I. INTRODUCTION 147 
 
 CHAP. II. SENSE AND ITS MAIN DECEPTION 148 
 
 CHAP. III. IMAGINATION AND DREAMS 153 
 
 CHAP. IV. THOUGHT 156 
 
 CHAP. VI. KNOWLEDGE AND BELIEF 160 
 
 CHAP. VII. THE PASSIONS 163 
 
 CHAP. XII. THE WILL 165 
 
 XIV. REN DESCARTES (1596-1650) 
 
 THE PASSIONS OF THE SOUL 168-190 
 
 Translated from the French by Henry A. P. Torrey. 
 
 XV. BARUCH DE SPINOZA (1632-1677) 
 
 THE ETHICS 191-207 
 
 Translated from the Latin by George Stuart Fullerton. 
 PART II. OF THE NATURE AND ORIGIN OF THE MIND. 
 (Prop. I-XXIII, XLVIII-XLIX.) 191 
 
 XVI. GOTTFRIED WILHELM VON LEIBNITZ 
 
 (1646-1716) 
 
 PHILOSOPHICAL WORKS 208-228 
 
 Translated from the French by George Martin Duncan. 
 XI. A NEW SYSTEM OF NATURE, AND OF THE INTERACTION 
 OF SUBSTANCES, AS WELL AS OF THE UNION WHICH EXISTS 
 BETWEEN THE SOUL AND THE BODY. 1695 2O8
 
 xvi CONTENTS 
 
 XIV. SECOND EXPLANATION OF THE SYSTEM OF COMMUNI- 
 CATION BETWEEN SUBSTANCES. 1696 218 
 
 XXXII. THE PRINCIPLES OF NATURE AND OF GRACE. 1714 220 
 
 XVII. CHRISTIAN VON WOLFF (1679-1754) 
 
 RATIONAL PSYCHOLOGY . . . 229-231 
 
 Translated from the Latin by Edward Kennard Rand. 
 THE ESSENCE AND NATURE OF THE SOUL 229 
 
 XVIII. JOHN LOCKE (1632-1704) 
 
 AN ESSAY CONCERNING HUMAN UNDERSTAND- 
 ING 232-255 
 
 BOOK I. CHAP. I. INTRODUCTION 232 
 
 BOOK II. OF IDEAS. 
 
 CHAP. I. Of Ideas in General 234 
 
 CHAP. II. Of Simple Ideas 236 
 
 CHAP. III. Of Simple Ideas of Sense 237 
 
 CHAP. IV. Idea of Solidity 239 
 
 CHAP. VI. Of Simple Ideas of Reflection 240 
 
 CHAP. VII. Of Simple Ideas of both Sensation and Re- 
 flection : 241 
 
 CHAP. VIII. Some Further Considerations concerning 
 
 our Simple Ideas of Sensation 242 
 
 CHAP. IX. Of Perception 246 
 
 CHAP. XII. Of Complex Ideas 249 
 
 BOOK IV. OF KNOWLEDGE 
 
 CHAP. I. Of Knowledge in General 253 
 
 XIX. GEORGE BERKELEY (1685-1753) 
 
 AN ESSAY TOWARDS A NEW THEORY OF VISION 256-278 
 
 XX. DAVID HUME (1711-1766) 
 
 A TREATISE OF HUMAN NATURE 279-3" 
 
 BOOK I. OF THE UNDERSTANDING. 
 PART I. OF IDEAS, THEIR ORIGIN, COMPOSITION, CON- 
 NEXION, &c. 
 
 SECTION I. Of the Origin of our Ideas 279 
 
 SECTION II. Division of the Subject 285 
 
 SECTION III. Of the Ideas of the Memory and Imagina- 
 tion 286 
 
 SECTION IV. Of the Connexion or Association of Ideas 287 
 
 SECTION V. Of Relations 200 
 
 SECTION VI. Of Modes and Substances 292 
 
 PART III. OF KNOWLEDGE AND PROBABILITY. 
 SECTION I. Of Knowledge . 294
 
 
 CONTENTS xvii 
 
 SECTION II. Of Probability; and of the Idea of Cause 
 
 and Effect V 297 
 
 SECTION XIV. Of the Idea of Necessary Connexion . . 302 
 
 XXI. DAVID HARTLEY (1705-1757) 
 OBSERVATIONS ON MAN, HIS FRAME, HIS 
 
 DUTY, AND HIS EXPECTATIONS 313-330 
 
 PART I. INTRODUCTION 313 
 
 CHAP. I. The Doctrines of Vibrations and Association 
 in General 315 
 
 SECTION I. The Doctrine of Vibrations, and its use for 
 explaining the Sensations 316 
 
 SECTION II. Of Ideas, their Generation and Associa- 
 tions 320 
 
 XXII. CHARLES BONNET (1720-1793) 
 
 ABSTRACT OF THE ANALYTICAL ESSAY UPON 
 
 THE FACULTIES OF THE SOUL 33*-34o 
 
 Translated from the French by Benjamin Rand. 
 
 XXIII. ETIENNE BONNOT DE CONDILLAC 
 
 (1715-1780) 
 
 TREATISE ON SENSATIONS 341-360 
 
 Translated from the French by Frederick C. de Sumichrast. 
 CHAP. I-III, VI-VII. FIRST NOTIONS, WILL AND PERSON- 
 ALITY OF A MAN LIMITED TO THE SENSE OF SMELL . . 34! 
 
 XXIV. THOMAS REID (1710-1796) 
 
 ESSAYS ON THE INTELLECTUAL POWERS OF 
 
 MAN 361-373 
 
 ESSAY II. OF THE POWERS WE HAVE BY MEANS OF OUR 
 EXTERNAL SENSES. 
 
 CHAP. V. Of Perception 361 
 
 CHAP. XVI. Of Sensation 367 
 
 XlV. THOMAS BROWN (1778-1820) 
 
 LECTURES ON THE PHILOSOPHY OF THE HU- 
 MAN MIND 374-394 
 
 PART II. OF THE EXTERNAL AFFECTIONS OF THE MIND. 
 
 CHAP. V. SECTION I. The Muscular Sensations . . . 374 
 
 \\ V\\ CHAP. V. SECTION II. Space Perception 380 
 
 PART III. OF THE INTELLECTUAL STATES OF THE MIND. 
 
 CHAP. I. SECTION II. Simple and Relative Suggestion . 389
 
 xviii CONTENTS 
 
 XXVI. JOHANN FRIEDRICH HERBART (1776- 
 1841) 
 
 A TEXT-BOOK IN PSYCHOLOGY 395-415 
 
 Translated from the German by Margaret K. Smith, 
 PART I. FUNDAMENTAL PRINCIPLES. 
 CHAP. I. The Condition of Concepts, when they act as 
 
 Forces 395 
 
 CHAP. II. Equilibrium and Movement of Concepts . . 397 
 
 CHAP. III. Complications and Blendings 400 
 
 CHAP. IV. Concepts as the Source of Mental States . 408 
 CHAP. V. The Co-operation of Several Masses of Con- 
 cepts of Unequal Strength 411 
 
 CHAP. VI. The Connection between Body and Soul . . 413 
 
 
 XXVII. FRIEDRICH EDUARD BENEKE (1798- 
 
 A TEXT-BOOK OF PSYCHOLOGY AS NATURAL 
 
 SCIENCE ................ 416-431 
 
 Translated from the German by Benjamin Rand. 
 CHAP. I. FUNDAMENTAL PROCESSES OF PSYCHICAL DE- 
 VELOPMENT ............... 416 
 
 CHAP. II. THE FUNDAMENTAL NATURE OF THE HUMAN 
 SOUL ................. 424 
 
 CHAP. III. THE RELATION or THE SOUL AND THE BODY . 426 
 
 XXVIII. MORITZ WILHELM DROBISCH (1802- 
 1896) 
 
 EMPIRICAL PSYCHOLOGY ACCORDING TO THE 
 
 METHODS OF NATURAL SCIENCE .... 432-447 
 
 Translated from the German by Benjamin Rand. 
 FIFTH SECTION. THE FUNDAMENTAL EXPLANATION OF 
 
 THE PSYCHICAL LIFE. 
 III. THE DYNAMICS OF IDEAS AS A PRINOTLE or EXPLANA- 
 
 TION OF PSYCHICAL PHENOMENA. 
 
 138. Interdependence of Psychical Phenomena ... 433 
 139. The Unity of the Soul as a Bond of Connection of 
 
 Psychical Phenomena ........... 433 
 
 140. The Refutation of the Faculty Concept . . . 435 
 141. Ideas as States and not Powers of the Mind . . 437 
 142. The Freedom and Inhibition of Ideas .... 439 
 
 143. The Inhibition of Opposing Ideas ...... 440 
 
 144. The Origin of Feelings and Desires ..... 442 
 
 145. The Equilibrium and Movement of Ideas . . . 443 
 146. The Stages in the Formation of the Spirit . . . 445
 
 CONTENTS xix 
 
 IX. FRANCOIS PIERRE GONTHIER MAINE 
 DE BIRAN (1766-1824) 
 
 ESSAY UPON THE FOUNDATIONS OF PSYCHO- 
 LOGY ... 448-462 
 
 Translated from the French by Benjamin Rand. 
 
 CHAP. I. FACTS or THE INNER SENSE 448 
 
 CHAP. II. THE ORIGIN OF EFFORT, AND OF PERSONALITY 455 
 
 'XXX. JAMES MILL (1773-1836) 
 
 ANALYSIS OF THE PHENOMENA OF THE HUMAN 
 
 MIND . 463-482 
 
 CHAP. III. THE ASSOCIATION OF IDEAS 463 
 
 XXXI. ALEXANDER BAIN (1818-1903) 
 
 THE SENSES AND THE INTELLECT 483-504 
 
 BOOK II. THE INTELLECT 483 
 
 CHAP. I. Retentiveness Law of Contiguity . . . 486 
 CHAP. II. Agreement Law of Similarity .... 490 
 
 CHAP. III. Compound Association 496 
 
 CHAP. IV. Of Constructive Association 504 
 
 XXXII. HERBERT SPENCER (1820-1903) 
 
 THE PRINCIPLES OF PSYCHOLOGY 505-529 
 
 PART II. THE INDUCTIONS OF PSYCHOLOGY. 
 
 CHAP. II. The Composition of Mind 505 
 
 XXXIII. JOHANNES MUELLER (1801-1858) 
 
 ELEMENTS OF PHYSIOLOGY 530-544 
 
 Translated from the German by William Baly. 
 BOOK V. OF THE SENSES. 
 The General Laws of Sensation 530 
 
 XXXIV. RUDOLF HERMANN LOTZE (1817-1881) 
 
 OUTLINES OF PSYCHOLOGY 545-556 
 
 Translated from the German by George Trumbull Ladd. 
 CHAP. IV. THE INTUITIONS OF SPACE 545 
 
 XXXV. ERNST HEINRICH WEBER (1795-1878) 
 
 THE SENSE OF TOUCH AND THE COMMON 
 
 FEELING 557-56i 
 
 Translated from the German by Benjamin Rand. 
 WEBER'S LAW 557
 
 xx CONTENTS 
 
 XXXVI. GUSTAV THEODOR FECHNER (1801- 
 
 1887) 
 
 ELEMENTS OF PSYCHOPHYSICS 562-572 
 
 Translated from the German by Herbert Sidney Lang f eld. 
 
 VII. THE MEASUREMENT OF SENSATION 562 
 
 XIV. THE FUNDAMENTAL FORMULA AND THE MEASURE- 
 MENT FORMULA 565 
 
 XXXVII. HERMANN VON HELMHOLTZ (1821- 
 1894) 
 
 A MANUAL OF PHYSIOLOGICAL OPTICS . . . 573-581 
 Translated from the German by Benjamin Rand. 
 THEORY OF COLOR VISION 573 
 
 XXXVIII. EWALDHERING (1834- ) 
 
 THEORY OF LIGHT SENSATION 582-596 
 
 Translated from the German by Benjamin Rand. 
 FUNDAMENTAL PRINCIPLES OF A THEORY OF LIGHT SENS- 
 ATION 
 
 25. Prefatory Remarks 582 
 
 26. The Nature of the Psychophysical Processes ... 585 
 27. Visual Sensation as Psychical Correlate of Chemical 
 
 Processes in the Visual Substance 587 
 
 28. The Deduction of Various Corollaries 592 
 
 29. The Weight of Visual Sensations 595 
 
 XXXIX. ERNST MACH (1838- ) 
 
 CONTRIBUTIONS TO THE ANALYSIS OF THE 
 
 SENSATIONS S97~6i8 
 
 Translated from the German by C. M. Williams. 
 
 THE SENSATIONS AS ELEMENTS 597 
 
 THE SPACE-SENSATIONS 611 
 
 XL. CARL STUMPF (1848- ) 
 
 THE PSYCHOLOGY OF TONE 619-632 
 
 Translated from the German by Benjamin Rand. 
 
 19. THE DEGREES OF TONAL FUSION 619 
 
 20. THE CAUSE OF TONAL FUSION 629 
 
 XLI. WILLIAM JAMES (1842-1910) 
 
 PSYCHOLOGY 633-671 
 
 CHAP. XI. THE STREAM OF CONSCIOUSNESS .... 633 
 CHAP. XXIV. EMOTION 655
 
 CONTENTS xxi 
 
 XLII. CARL GEORG LANGE (1834-1900) 
 
 THE EMOTIONS 672-684 
 
 Translated from the German of H. Kurella by Benjamin Rand. 
 THE MECHANISM OF THE EMOTIONS 672 
 
 XLIII. WILHELM WUNDT (1832- ) 
 
 PRINCIPLES OF PHYSIOLOGICAL PSYCHOLOGY 685-696 
 Translated from the German by Edward Bradford Titchener. 
 INTRODUCTION. 
 
 i. The Problem of Physiological Psychology .... 685 
 3. Prepsychological Concepts 691 
 
 OUTLINES OF PSYCHOLOGY 697-726 
 
 Translated from the German by Charles Hubbard Judd. 
 II. PSYCHICAL "COMPOUNDS. 
 
 14. Volitional Processes 697 
 
 III. INTERCONNECTION OF PSYCHICAL COMPOUNDS. 
 
 17. Apperceptive Combinations 711 
 
 INDEX 727
 
 THE 
 CLASSICAL PSYCHOLOGISTS 
 
 ANAXAGORAS EMPEDOGLES 
 
 (500-428 B.C.) (490-430) 
 
 DEMOGRITUS 
 
 (460-370) 
 
 FROM ARISTOTLE'S DE ANIMA 
 
 Translated from the Greek * by 
 R. D. HICKS 
 
 BOOK I 
 CHAPTER I INTRODUCTION OF ARISTOTLE 
 
 COGNITION is in our eyes a thing of beauty and worth, and this 
 is true of one cognition more than another, either because it is 
 exact or because it relates to more important and remarkable 
 objects. On both these grounds we may with good reason claim 
 a high place for the enquiry concerning the soul. It would seem, 
 too, that an acquaintance with the subject contributes greatly 
 to the whole domain of truth and, more particularly, to the 
 study of nature, the soul being virtually the principle of all 
 animal life. Our aim is to discover and ascertain the nature and 
 essence of soul and, in the next place, all the accidents belonging 
 to it; of which some are thought to be attributes peculiar to the 
 soul itself, while others, it is held, belong to the animal also, but 
 owe their existence to the soul. But everywhere and in every 
 way it is extremely difficult to arrive at any trustworthy con- 
 
 * From 'ApwTOTAot>j Utol *vxv. Reprinted from Aristotle's De Anima, 
 translated by R. D. Hicks. Cambridge, University Press, 1907.
 
 2 INTRODUCTION 
 
 elusion on the subject. It is the same here as in many other 
 enquiries. What we have to investigate is the essential nature 
 of things and the What. It might therefore be thought that 
 there is a single procedure applicable to all the objects whose 
 essential nature we wish to discover, as demonstration is appli- 
 cable to the properties which go along with them : in that case 
 we should have to enquire what this procedure is. If, however, 
 there is no single procedure common to all sciences for denning 
 the What, our task becomes still more difficult, as it will then 
 be necessary to settle in each particular case the method to be 
 pursued. Further, even if it be evident that it consists in de- 
 monstration of some sort or division or some other procedure, 
 there is still room for much perplexity and error, when we ask 
 from what premisses our enquiry should start, for there are dif- 
 ferent premisses for different sciences; for the science of num- 
 bers, for example, and plane geometry. 
 
 The first thing necessary is no doubt to determine under 
 which of the summa genera soul comes and what it is; I mean, 
 whether it is a particular thing, i.e. substance, or is quality or 
 is quantity, or falls under any other of the categories already 
 determined. We must further ask whether it is amongst things 
 potentially existent or is rather a sort of actuality, the distinc- 
 tion being all-important. Again, we must consider whether it 
 is divisible or indivisible; whether, again, all and every soul is 
 homogeneous or not; and, if not, whether the difference be- 
 tween the various souls is a difference of species or a difference 
 of genus: for at present discussions and investigations about 
 soul would appear to be restricted to the human soul. We must 
 take care not to overlook the question whether there is a single 
 definition of soul answering to a single definition of animal; or 
 whether there is a different definition for each separate soul, as 
 for horse and dog, man and god: animal, as the universal, being 
 regarded either as non-existent or, if existent, as logically pos- 
 terior. This is a question which might equally be raised in re- 
 gard to any other common predicate. Further, on the assump- 
 tion that there are not several souls, but merely several different 
 parts in the same soul, it is a question whether we should begin
 
 ARISTOTLE'S DE ANIMA 3 
 
 by investigating soul as a whole or its several parts. And here 
 again it is difficult to determine which of these parts are really 
 distinct from one another and whether the several parts, or 
 their functions, should be investigated first. Thus, e.g., should 
 the process of thinking come first or the mind that thinks, the 
 process of sensation or the sensitive faculty? And so everywhere 
 else. But, if the functions should come first, again will arise the 
 question whether we should first investigate the correlative 
 objects. Shall we take, e.g., the sensible object before the fac- 
 ulty of sense and the intelligible object before the intellect? 
 
 It would seem that not only is the knowledge of a thing's 
 essential nature useful for discovering the causes of its attri- 
 butes, as, e.g., in mathematics the knowledge of what is meant 
 by the terms straight or curved, line or surface, aids us in dis- 
 covering to how many right angles the angles of a triangle are 
 equal: but also, conversely, a knowledge of the attributes is a 
 considerable aid to the knowledge of what a thing is. For when 
 we are able to give an account of all, or at any rate most, of the 
 attributes as they are presented to us, then we shall be in a posi- 
 tion to define most exactly the essential nature of the thing. 
 In fact, the starting point of every demonstration is a defini- 
 tion of what something is. Hence the definitions which lead 
 to no information about attributes and do not facilitate even 
 conjecture respecting them have clearly been framed for dia- 
 lectic and are void of content, one and all. 
 
 A further difficulty arises as to whether all attributes of the 
 soul are also shared by that which contains the soul or whether 
 any of them are peculiar to the soul itself: a question which it is 
 indispensable, and yet by no means easy, to decide. It would 
 appear that in most cases soul neither acts nor is acted upon 
 apart from the body: as, e.g., in anger, confidence, desire and 
 sensation in general. Thought, if anything, would seem to be 
 peculiar to the soul. Yet, if thought is a sort of imagination, or 
 not independent of imagination, it will follow that even thought 
 cannot be independent of the body. If, then, there be any of 
 the functions or affections of the soul peculiar to it, it will be 
 possible for the soul to be separated from the body : if, on the
 
 4 INTRODUCTION 
 
 other hand, there is nothing of the sort peculiar to it, the soul 
 will not be capable of separate existence. As with the straight 
 line, so with it. The line, qua straight, has many properties; for 
 instance, it touches the brazen sphere at a point; but it by no 
 means follows that it will so touch it if separated. In fact it is 
 inseparable, since it is always conjoined with body of some sort. 
 So, too, the attributes of the soul appear to be all conjoined with 
 body: such attributes, viz., as anger, mildness, fear, pity, cour- 
 age; also joy, love and hate; all of which are attended by some 
 particular affection of the body. This indeed is shown by the 
 fact that sometimes violent and palpable incentives occur with- 
 out producing in us exasperation or fear, while at other times 
 we are moved by slight and scarcely perceptible causes, when 
 the blood is up and the bodily condition that of anger. Still 
 more is this evident from the fact that sometimes even without 
 the occurrence of anything terrible men exhibit all the symp- 
 toms of terror. If this be so, the attributes are evidently forms 
 or notions realised in matter. Hence they must be denned ac- 
 cordingly: anger, for instance, as a certain movement in a body 
 of a given kind, or some part or faculty of it, produced by such 
 and such a cause and for such and such an end. These facts at 
 once bring the investigation of soul, whether in its entirety or 
 in the particular aspect described, within the province of the 
 natural philosopher. But every such attribute would be differ- 
 ently denned by the physicist and the dialectician or philoso- 
 pher. Anger, for instance, would be denned by the dialectician 
 as desire for retaliation or the like, by the physicist as a ferment 
 of the blood or heat which is about the heart: the one of them 
 gives the matter, the other the form or notion. For the notion 
 is the form of the thing, but this notion, if it is to be, must be 
 realised in matter of a particular kind; just as in the case of a 
 house. The notion or definition of a house would be as follows: 
 a shelter to protect us from harm by wind or rain or scorching 
 heat; while another will describe it as stones, bricks and tim- 
 ber; and again another as the form realised in these materials 
 and subserving given ends. Which then of these is the true phy- 
 sicist? Is it he who confines himself to the matter, while ignor-
 
 ARISTOTLE'S DE ANIMA 5 
 
 ing the form? Or he who treats of the form exclusively? I an- 
 swer, it is rather he who in his definition takes account of both. 
 What then of each of the other two? Or shall we rather say 
 that there is no one who deals with properties which are not 
 separable nor yet treated as separable, but the physicist deals 
 with all the active properties or passive affections belonging to 
 body of a given sort and the corresponding matter? All attri- 
 butes not regarded as so belonging he leaves to someone else: 
 who in certain cases is an expert, a carpenter, for instance, or 
 a physician. The attributes which, though inseparable, are not 
 regarded as properties of body of a given sort, but are reached 
 by abstraction, fall within the province of the mathematician: 
 while attributes which are regarded as having separate exist- 
 ence fall to the first philosopher or metaphysician. But to 
 return to the point of digression. We were saying that the 
 attributes of the soul are as such, I mean, as anger and 
 fear, inseparable from the physical matter of the animals to 
 which they belong, and not, like line and surface, separable in 
 thought. 
 
 CHAPTER II EARLY PSYCHOLOGICAL THEORIES 
 
 IN our enquiry concerning soul it is necessary to state the 
 problems which must be solved as we proceed, and at the same 
 time to collect the views of our predecessors* who had anything 
 to say on the subject, in order that we may adopt what is right 
 in their conclusions and guard against their mistakes. Our en- 
 quiry will begin by presenting what are commonly held to be in 
 a special degree the natural attributes of soul. Now there are 
 two points especially wherein that which is animate is held to 
 differ from the inanimate, namely, motion and the act of sensa- 
 tion : and these are approximately the two characteristics of soul 
 handed down to us by our predecessors. There are some who 
 
 * Aristotle introduces here the first extant history of psychological theo- 
 ries.
 
 6 ANAXAGORAS 
 
 maintain that soul is preeminently and primarily the cause of 
 movement. But they imagined that that which is not itself in 
 motion cannot move anything else, and thus they regarded the 
 soul as a thing which is in motion. Hence Democritus affirms 
 the soul to be a sort of fire or heat. For the "shapes" or atoms 
 are infinite and those which are spherical he declares to be fire 
 and soul : they may be compared with the so-called motes in the 
 air, which are seen in the sunbeams that enter through our win- 
 dows. The aggregate of such seeds, he tells us, forms the consti- 
 tuent elements of the whole of nature (and herein he agrees with 
 Leucippus), while those of them which are spherical form the 
 soul, because such figures most easily find their way through 
 everything and, being themselves in motion, set other things in 
 motion. The atomists assume that it is the soul which imparts 
 motion to animals. It is for this reason that they make life de- 
 pend upon respiration. For, when the surrounding air presses 
 upon bodies and tends to extrude those atomic shapes which, 
 because they are never at rest themselves, impart motion to 
 animals, then they are reinforced from outside by the entry of 
 other like atoms in respiration, which in fact, by helping to 
 check compression and solidification, prevent the escape of the 
 atoms already contained in the animals; and life, so they hold, 
 continues so long as there is strength to do this. The doctrine 
 of the Pythagoreans seems also to contain the same thought. 
 Some of them identified soul with the motes in the air, others 
 with that which sets these motes in motion : and as to these 
 motes it has been stated that they are seen to be in incessant 
 motion, even though there be a perfect calm. The view of 
 others who describe the soul as that which moves itself tends in 
 the same direction. For it would seem that all these thinkers 
 regard motion as the most distinctive characteristic of the soul. 
 Everything else, they think, is moved by the soul, but the soul is 
 moved by itself: and this because they never see anything cause 
 motion without itself being in motion. Similarly the soul is said 
 to be the moving principle by Anaxagoras and all others who 
 have held that mind sets the universe in motion; but not alto- 
 gether in the same sense as by Democritus. The latter, indeed,
 
 ARISTOTLE'S DE ANIMA 7 
 
 i 
 
 absolutely identified soul and kind, holding that the presenta- 
 tion to the senses is the truth : hence, he observed, Homer had 
 well sung of Hector in his swoon that he lay 'with other 
 thoughts.' Democritus, then, does not use the term mind to de- 
 note a faculty conversant with truth, but regards mind as iden- 
 tical with soul. Anaxagoras, however, is less exact in his use of 
 the terms. In many places he speaks of mind as the cause of 
 goodness and order, but elsewhere he identifies it with the soul: 
 as where he attributes it to all animals, both great and small, 
 high and low. As a matter of fact, however, mind in the sense 
 of intelligence would not seem to be present in all animals alike, 
 nor even in all men. 
 
 Those, then, who have directed their attention to the motion 
 of the animate being, conceived the soul as that which is most 
 capable of causing motion: while those who laid stress on its 
 knowledge and perception of all that exists identified the soul 
 with the ultimate principles, whether they recognised a plu- 
 rality of these or only one. Thus Empedocles compounded soul 
 out of all the elements, while at the same time regarding each 
 one of them as a soul. His words are "With earth we see earth, 
 with water water, with air bright air, but ravaging fire by fire, 
 love by love, and strife by gruesome strife." In the same man- 
 ner Plato in the Timaeus constructs the soul out of the ele- 
 ments. Like, he there maintains, is known by like, and the 
 things we know are composed of the ultimate principles. In 
 like manner it was explained in the lectures on philosophy, 
 that the self-animal or universe is made up of the idea of One, 
 and of the idea-numbers Two, or primary length, Three, pri- 
 mary breadth, and Four, primary depth, and similarly with all 
 the rest of the ideas. And again this has been put in another 
 way as follows : reason is the One, knowledge is the Two, because 
 it proceeds by a single road to one conclusion, opinion is the 
 number of a surf ace, Three, and sensation the number of a solid, 
 Four. In fact, according to them the numbers, though they are 
 the ideas themselves, or the ultimate principles, are neverthe- 
 less derived from elements. And things are judged, some by 
 reason, others by knowledge, others again by opinion and others
 
 8 EMPEDOCLES 
 
 by sensation: while these idea-numbers are forms of things. 
 And since the soul was held to be thus cognitive as well as 
 capable of causing motion, some thinkers have combined the 
 two and denned the soul as a self-moving number. 
 
 But there are differences of opinion as to the nature and 
 number of the ultimate principles, especially between those 
 thinkers who make the principles corporeal and those who make 
 them incorporeal; and again between both of these and others 
 who combine the two and take their principles from both. But, 
 further, they differ also as to their number: some assuming a 
 single principle, some a plurality. And, when they come to give 
 an account of the soul, they do so in strict accordance with their 
 several views. For they have assumed, not unnaturally, that 
 the soul is that primary cause which in its own nature is capable 
 of producing motion. And this is why some identified soul with 
 fire, this being the element which is made up of the finest parti- 
 cles and is most nearly incorporeal, while further it is preemi- 
 nently an element which both moves and sets other things in 
 motion. Democritus has expressed more neatly the reason for 
 each of these facts. Soul he regards as identical with mind, and 
 this he makes to consist of the primary indivisible bodies and 
 considers it to be a cause of motion from the fineness of its par- 
 ticles and their shape. Now the shape which is most susceptible 
 of motion is the spherical; and of atoms of this shape mind, 
 like fire, consists. Anaxagoras, while apparently understand- 
 ing by mind something different from soul, as we remarked 
 above, really treats both as a single nature, except that it is 
 preeminently mind which he takes as his first principle; he 
 says at any rate that mind alone of things that exist is simple, 
 unmixed, pure. But he refers both knowledge and motion to 
 the same principle, when he says that mind sets the universe in 
 motion. Thales, too, apparently, judging from the anecdotes 
 related of him, conceived soul as a cause of motion, if it be true 
 that he affirmed the loadstone to possess soul, because it at- 
 tracts iron. Diogenes, however, as also some others, identified 
 soul with air. Air, they thought, is made up of the finest parti- 
 cles and is the first principle: and this explains the fact that the
 
 ARISTOTLE'S DE ANIMA 9 
 
 soul knows and is a cause of motion, knowing by virtue of being 
 the primary element from which all else is derived, and causing 
 motion by the extreme fineness of its parts. Heraclitus takes 
 soul for his first principle, as he identifies it with the vapour 
 from which he derives all other things, and further says that it 
 is the least corporeal of things and in ceaseless flux ; and that 
 it is by something in motion that what is in motion is known; 
 for he, like most philosophers, conceived all that exists to be 
 in motion. Alcmaeon, too, seems to have had a similar concep- 
 tion. For soul, he maintains, is immortal because it is like the 
 beings which are immortal; and it has this attribute in virtue of 
 being ever in motion: for he attributes continuous and unending 
 motion to everything which is divine, moon, sun, stars and the 
 whole heaven. Among cruder thinkers there have been some, 
 like Hippon, who have even asserted the soul to be water. The 
 reason for this view seems to have been the fact that in all ani- 
 mals the seed is moist: in fact, Hippon refutes those who make 
 the soul to be blood by pointing out that the seed is not blood, 
 and that this seed is the rudimentary soul. Others, again, like 
 Critias, maintain the soul to be blood, holding that it is sentience 
 which is most distinctive of soul and that this is due to the 
 nature of blood. Thus each of the four elements except earth 
 has found its supporter. Earth, however, has not been put for- 
 ward by anyone, except by those who have explained the soul 
 to be derived from, or identical with, all the elements. 
 
 Thus practically all define the soul by three characteristics, 
 motion, perception and incorporeality; and each of these char- 
 acteristics is referred to the ultimate principles. Hence all who 
 define soul by its capacity for knowledge either make it an ele- 
 ment or derive it from the elements, being on this point, with 
 one exception, in general agreement. Like, they tell us, is known 
 by like; and therefore, since the soul knows all things, they say 
 it consists of all the ultimate principles. Thus those thinkers 
 who admit only one cause and one element, as fire or air, assume 
 the soul also to be one element; while those who admit a plurality t 
 of principles assume plurality also in the soul. Anaxagoras alone 
 says that mind cannot be acted upon and has nothing in com-
 
 io DEMOCRITUS 
 
 mon with any other thing. How, if such be its nature, it will 
 know anything and how its knowledge is to be explained, he 
 has omitted to state; nor do his utterances afford a clue. All 
 those who introduce pairs of opposites among their principles 
 make the soul also to consist of opposites; while those who take 
 one or other of the two opposites, either hot or cold or some- 
 thing else of the sort, reduce the soul also to one or other of these 
 elements. Hence, too, they etymologise according to their the- 
 ories; some identify soul with heat, deriving tyv from &lv, and 
 contend that this identity accounts for the word for life; others 
 say that what is cold is called soul from the respiratory process 
 and consequent "cooling down," deriving ^-vxn from ^v-^iv. 
 Such, then, are the views regarding soul which have come down 
 to us and the grounds on which they are held.
 
 PROTAGORAS SOCRATES 
 
 (480-411) (469-399) 
 
 FROM PLATO'S THEAETETUS 
 
 Translated from the Greek* by 
 SAMUEL WALTERS DYDE 
 
 THE NATURE OF PERCEPTION 
 SOCRATES THEAETETUS 
 
 Steph. 152. 
 
 Soc. . . . Knowledge is perception, you say? 
 
 Theaet. Yes. 
 
 Soc. This is surely no trifling matter, for you have likely 
 given, though in other words, the definition of Protagoras. He 
 says that man is the measure of all things (jravrmv ^p^^drmv 
 fterpov avdpwTrov), both of the existence of things which exist, 
 and the non-existence of things which exist not (r&v pev OVTOJV, &>? 
 ecrri, TOJV Se pr] OVTCOV, to? OVK eo-riv). Have you never read that? 
 
 Theaet. Yes, many a time. 
 
 Soc. Does he not mean that things exist for me as they ap- 
 pear (<f>aivTjTai') to me, and for you as they appear to you, since 
 you and I are men? 
 
 Theaet. So he says, at any rate. 
 
 Soc. As it is highly probable that a wise man does not talk 
 nonsense, let us look for his meaning. Sometimes when the 
 wind is blowing on all alike is not one of us cold and another 
 not, or one slightly and another exceedingly cold? 
 
 Theaet. No doubt. 
 
 Soc. In that case shall we say that the wind in itself (avrb e'</>' 
 eavTo) is cold or not cold? Or shall we agree with Protagoras 
 that it is cold to him who is cold and not to him who is not? 
 
 Theaet. Protagoras seems to be right. 
 
 * From nXdrwi'as GeairijTos. Reprinted from The Theaetetus of Plato, trans- 
 lated by S. W. Dyde. Glasgow, 1899.
 
 12 PROTAGORAS 
 
 Soc. Then it is to each as it appears to him? 
 
 Theaet. Yes. 
 
 Soc. And what appears is perceived? 
 
 Theaet. Truly. 
 
 Soc. Then in the case of such things as heat and cold appear- 
 ance ((fravrao-ia) and perception are one and the same. Every 
 such thing, I daresay, exists as it is perceived? 
 
 Theaet. That would seem to be so. 
 
 Soc. And perception of reality (roO 01/1-09), since it is know- 
 ledge, can never be false? 
 
 Theaet. So it appears. 
 
 Soc. Then charmingly keen-witted was it of Protagoras to 
 hint darkly at these things to us of the common crowd, while 
 telling the truth to his disciples in secret. 
 
 Theaet. What do you mean by that, Socrates? 
 
 Soc. I shall tell you of a by no means contemptible theory 
 to the effect that nothing exists purely by itself (CLVTO icaff* CIVTO), 
 nor can you rightly give anything an exclusive name. If you 
 speak of the large, you suggest the small, if of the heavy, you 
 suggest the light, and so on. Nothing, be it either an attribute 
 (TIW?), or a kind of thing (OTTOLOVOVV) , exists alone (ei/o?). 
 Moreover, it is inaccurate to speak of existence as the result of 
 motion, collision and combination, since nothing really exists, 
 but everything is always in process of change (yiyverai). On 
 this point the whole array of wise men, except Parmenides, are 
 agreed, Protagoras, Heraclitus, Empedocles, also the most 
 famous names in both kinds of poetry, in comedy Epicharmus, 
 and in tragedy Homer. When Homer says: Ocean and mother 
 Tethys are the parents of the gods, he means that all the gods 
 have sprung from ceaseless movement (por)? re KOI /aircrew) . 
 Do you not think that this was his view? 
 
 Theaet. Yes. 
 
 Soc. Could we contend with this mighty host, whose captain 
 is Homer, without laying ourselves open to ridicule? 
 
 Theaet. It would be a risk, Socrates. 
 
 Soc. Yes indeed, Theaetetus, since there are good proofs that 
 what appears to be and comes into existence is produced by
 
 PLATO'S THEAETETUS 13 
 
 motion, and what does not exist and perishes is produced by 
 rest. For example, heat and fire, which produce and nourish 
 everything else, are themselves produced by friction, which is 
 motion. Is not that the source of fire? 
 
 Theaet. Yes. 
 
 Soc. And has not the race (yevos) of animals sprung from 
 the same source? 
 
 Theaet. It has surely. 
 
 Soc. Why, what else? Is not the fashion (et<?) of the body 
 destroyed by rest and inaction and preserved largely by exercise 
 and movement? 
 
 Theaet. Certainly. 
 
 Soc. And the soul, is it not taught and preserved and im- 
 proved by study and practice, which are motions, while through 
 idleness, neglect and inattention it fails to learn, or what it 
 learns it forgets? 
 
 Theaet. That is true. 
 
 Soc. Is motion not a good, then, for soul and body, and rest 
 the reverse of good? 
 
 Theaet. Evidently. 
 
 Soc. May I not say further that storms preserve, while still- 
 ness and calm and all such states of rest corrupt and destroy? 
 And I am constrained to give this crowning illustration, that so 
 long as the universe and the golden chain, as Homer calls the 
 sun, move onward in their course, all things divine and human 
 manifestly contrive to exist and are preserved; but, if they 
 should stand still, everything would be destroyed, and then 
 would come to pass the saying that the whole world is turned 
 upside down. 
 
 Theaet. Your explanation, I think, is clear, Socrates. 
 
 Soc. Consider this, my friend, with regard first of all to the 
 sense of sight. What you call whiteness does not exist in your 
 eyes nor as an object outside of them, nor could you assign to it 
 any particular place, for it would then be something fixed and 
 stationary and not continuously generated. 
 
 Theaet. How is that? 
 
 Soc. Let us apply our former argument, in which we decided
 
 i 4 PROTAGORAS 
 
 that nothing exists as one thing and utterly by itself, and it will 
 appear that white, black, or any other colour is produced when 
 the glance of the eye comes into contact with the proper mo- 
 tion. What we call a colour is neither the eye nor the object, 
 but something which arises between them, and is different with 
 different individuals. Or, would you contend that a colour ap- 
 pears to you as it does to an animal, a dog for instance? 
 
 Theaet. No indeed, I would not. 
 
 Soc. Then would you hold that two human beings might 
 have the same perceptions? Are you not sure, rather, that not 
 even to yourself does a thing twice appear the same, since both 
 you and it are continually changing? 
 
 Theaet. Yes, I feel sure of that. 
 
 Soc. Yet if the object, which we touch and compare in size 
 with ourselves, be large or white or hot, it would not, when 
 contrasted with one thing, be different from what it is when 
 contrasted with another, provided that it itself had suffered no 
 change. Or, if it is the faculty, whether of measuring or touch, 
 which is large or white or hot, then, if it were itself unmodified, 
 it would not be changed merely by experiencing and coming 
 into contact with different objects. So, you see, our want of 
 thought leads us into amazing absurdities, as Protagoras and 
 his school would say. 
 
 Theaet. What do you mean by that? 
 
 Soc. You will understand what I mean, if I use a simple 
 illustration. If you take six dice, you would say that they, when 
 compared with four, were more by half as many again, and 
 when compared with twelve they were less and only one-half. 
 Could you deny the truth of that? 
 
 Theaet. No indeed. 
 
 Soc. Well then, if Protagoras or somebody else says to you, 
 
 Theaetetus, can a thing possibly become more or greater, 
 unless it be increased? What will you answer? 
 
 Theaet. If I answer the simple question as I really think, 
 
 1 must say No, but in view of what you have just said and to 
 avoid a contradiction, I must say Yes. 
 
 Soc. Well and divinely spoken, friend! And yet it strikes me
 
 PLATO'S THEAETETUS 15 
 
 that if you say Yes, it will be with you according to the saying 
 of Euripides: 'The tongue will be unrefuted, but the mind not 
 unrefuted.' 
 
 Theaet. True. 
 
 Soc. If we had been veteran sophists (Seivol /cal o-o<ot'), you 
 and I, and had carefully scrutinized all the things of the 
 mind, we would at the very outset have made an abundant 
 trial of our opponents, as they of us; we would have come up to 
 the contest warily (aofaa-TiKw), and there would have been a 
 clashing of words with words. But, as it is, we are only private 
 folks whose foremost wish is to behold things as they are (avrcL 
 7T/30? aura), and to see if our thoughts are consistent or not. 
 
 Theaet. That is certainly my desire. 
 
 Soc. And mine. Shall we not, then, as we have lots of time, 
 retrace our steps a little, and examine ourselves calmly and 
 earnestly, in order to see what these images in us are? The first 
 of them we shall, I think, decide to be that nothing ever be- 
 comes more or less either in size or number, while it is equal to 
 itself. Is not that so? 
 
 Theaet. Yes. 
 
 Soc. And the second is that that, to which nothing is added 
 and from which nothing is taken away, is neither increased nor 
 diminished, but is always equal to itself. 
 
 Theaet. Assuredly. 
 
 Soc. Is there not a third, that nothing, which did not exist 
 before, can now exist, without becoming and having become ? 
 
 Theaet. Agreed. 
 
 Soc. These three postulates, I think, were striving together 
 in our soul when we spoke of the dice, and are present again in 
 the following instance: Suppose that you were shorter than I at 
 the beginning of the year, but taller at the end, not because I 
 had diminished in size, for men of my age do not change, but 
 because you, who are young, had meanwhile grown. It is mani- 
 fest that I was once what I was not afterwards, although I had 
 not become. For, as to haye become is plainly impossible with- 
 out becoming, I could not have become smaller without losing 
 in size. And there are thousands of similar instances, if indeed
 
 16 PROTAGORAS 
 
 we choose to admit them. I see that you follow me, Theaetetus, 
 for you are likely not unacquainted with such puzzles. 
 
 Theaet. By the gods, Socrates, when I look into them I am 
 smitten with wonder, and truly sometimes my brain reels. 
 
 Soc. So Theodorus made not a bad guess at your disposi- 
 tion, my friend, since the very state of a philosopher is wonder. 
 Indeed the man seems to have been a wise genealogist who said 
 that Iris was the daughter of Thaumas, for wonder is the only 
 beginning of philosophy. Do you begin to understand what is 
 the solution of your difficulty on the views which we are ascrib- 
 ing to Protagoras? 
 
 Theaet. Not yet. 
 
 Soc. Will you count it a favour if I examine with you into the 
 secret reasoning, which is held as the truth by him and other 
 celebrated men ? 
 
 Theaet. I will count it a very great favour. 
 
 Soc. Look over the company, so that no profane person may 
 overhear. For there are people who believe in nothing but what 
 they can fasten upon with both hands, contending that action 
 and generation and all the things, which are not seen, do not 
 exist at all. 
 
 Theaet. They must be hardened and repulsive creatures. 
 
 Soc. That they are, my boy, utterly illiterate. But it is 
 another much more subtle sect, of whose mysteries I mean to 
 inform you. Their first principle, that upon which our state- 
 ment depends, is that all is motion (TO trav KLvrja-ts) or that 
 nothing exists except motion. There are two kinds (et'S*;) of 
 motion, each unlimited in its range, to act and to suffer or be 
 acted upon. From the strife and union of these two powers 
 (Svvdfj&is) is produced an innumerable brood twofold in its 
 nature, namely the object of sense, and sense, which is always 
 connate and coincident with it, object. The sensible percep- 
 tions are called sight, hearing, smell, the sense of hot and cold, 
 and also pleasures, pains, desires and fears. These and man)'' 
 others have names, and there are numberless others without 
 names. Correlative with sight are colours of all kinds, sounds 
 with hearr i. and with each of the other senses its kindred
 
 PLATO'S THEAETETUS 17 
 
 objects. Has this tale anything to do, Theaetetus, with what 
 has gone before ? Do you know ? 
 Theaet. Socrates, I do not. 
 
 Soc. Give heed, then, and you shall see the connection. All 
 these things, as we have said, are in movement. Now in the 
 movement of them there are swiftness and slowness. That 
 which is slow moves in one place, and is affected by things close 
 at hand, and so produces, but the things produced by it are 
 swifter, since their movement is a change of place. Let us sup- 
 pose that the eye and its corresponding visible object approach 
 and produce whiteness and the concomitant sensation, a result 
 which would not take place if either the eye or the object came 
 into contact with anything else. When the union of these two 
 occurs, sight moving from the eye and meeting whiteness mov- 
 ing from the object, which helps to produce the colour, the eye 
 becomes filled with vision, and now sees, and becomes not vision 
 but seeing eye. The object, in turn, having aided in making 
 the colour, is filled with whiteness, and becomes not whiteness 
 but white, be it wood or stone or any object, which chanced to 
 be of this colour. All other sensations, hard, warm and the rest, 
 must be treated in the same way. Not one of them, as we have 
 said already, can be understood as having any existence of itself 
 (avro /caO' auro), but all are produced by movement through 
 union each with its proper counterpart. There can be no solid 
 cognition (vorja-at) , as they say, of either the active element or 
 the passive element taken separately (eVt ew?) ; for there is an 
 active element only as it is found in union with the passive, and 
 , a passive element only as it is found in union with the active. 
 The uniting and active element, when it comes into contact with 
 another thing, is to be regarded as passive. Accordingly on all 
 these counts, nothing, as we said at the outset, exists as one 
 thing by itself (ev avrb icaff avro), but everything always 
 becomes for some other thing (TIVL yfyveffdcu). Being or 
 existence (TO elvcu) must be thoroughly eradicated, though we 
 are often, as just now, compelled, it would seem, through cus- 
 tom and ignorance to make use of the term. And yet, according 
 to the wise (01 cro^ot), we must not permit anyone to use such
 
 18 PROTAGORAS 
 
 expressions as { it' or 'of it' or 'mine' or 'this' or 'that' or any 
 other name which gives fixity, but only to conform to nature 
 and say that things become, are in process of creation, and are 
 being destroyed and changed. Thus, if anyone in an argument 
 establishes anything, he is easy to refute. Besides, we must 
 speak in this way not only of separate things but of any collec- 
 tion, such as man, stone, any species of animal or any genus 
 (etSo?). Do these things seem pleasant to you, Theaetetus, 
 and have they a grateful flavour? 
 
 Theaet. I am sure I do not know, Socrates, for I cannot de- 
 cide whether you believe what you say or are only making trial 
 of me. 
 
 Soc. You really forget, my friend, that I know nothing and 
 produce nothing of my own, for I am childless. But I wait on 
 you, and therefore seek to charm you by giving you to taste of 
 every philosopher (o-o^o?), until at last I may have aided in 
 bringing your theory out into the light. When this Js done, I 
 shall see whether it is an empty thing or a genuine reality. So, 
 be bold, and persevere, and answer sturdily to what I ask you. 
 
 Theaet. Well then, put your questions. 
 
 Sac. Tell me again if you are satisfied that nothing is, but all 
 is ever becoming, the good and beautiful as well as all the things 
 which we have just enumerated. 
 
 Theaet. To speak frankly, when I hear your argument in 
 detail, I think it very reasonable and must accept it. 
 
 Soc. Let us, then, see the theory completed. It remains to 
 speak of dreams and diseases, especially madness with its 
 illusions of sight and hearing and other senses. In all these 
 cases, as you must admit, the position which we have just taken 
 seems to be refuted, since manifestly there arise in ourselves 
 perceptions which are false. Consequently what appears to 
 each person is far from being real; on the exact contrary not a 
 single appearance is real. 
 
 Theaet. You speak truly, Socrates. 
 
 Soc. What argument (Xttyos), my boy, is left to him who 
 holds that sensible perception is knowledge, and that each one's 
 appearances (ra <f>aivd/jva) are for him real?
 
 PLATO'S THEAETETUS 19 
 
 Theaet. I hesitate to tell you, Socrates, that I do not know 
 what to say, because you reproved me a moment ago for giving 
 this answer. Yet I cannot, indeed, argue that madmen and 
 dreamers think truly, some in supposing that they are gods, 
 and others in dreaming that they have wings and are flying. 
 
 Soc. Do you not perceive that in these cases, especially in 
 dreams and madness, a rejoinder may be made of this nature? 
 
 Theaet. Of what nature? 
 
 Soc. You have doubtless often heard it asked: What proof 
 would you give, if you were questioned at this moment whether 
 we are sleeping and dreaming all this discussion, or awake and 
 conversing about a waking thought? 
 
 Theaet. Truly, Socrates, it would be hard to prove it, for 
 sleep and waking are equally real, and one is the counterpart 
 of the other. There is nothing to prevent our supposing that 
 we are now talking together in our sleep. And when in dreams 
 we seem to be telling our dreams, such a state strangely resem- 
 bles our waking life. 
 
 Soc. It is not hard, you see, to carry on the dispute, when it 
 may be doubted even whether we are asleep or awake. If we 
 divide time about equally between sleep and waking, in each 
 period our souls are maintaining that their present opinions 
 (Soy/jiaTa) are true. Thus for one half of our days we say that 
 some opinions are true, and for the other half that different 
 opinions are true. Yet we hold fast by both. 
 
 Theaet. Clearly. 
 
 Soc. Does not the same argument apply to diseases and mad- 
 ness, except only that the time is not divided equally? 
 
 Theaet. True. 
 
 Soc. And is the truth to be determined by length or shortness 
 of time? 
 
 Theaet. That would be absurd. 
 
 Soc. Can you by any other way clearly show on which side 
 the truth is? 
 
 Theaet. I think not. 
 
 Soc. You shall hear, then, what is said about this by those 
 who determine that what seems (TO. SOKOVVTO) to anyone to be
 
 20 PROTAGORAS 
 
 true is true for him. They would put some such question as this 
 to you, "O Theaetetus, can two things entirely different have 
 the same quality (Swapis') ? " Their question, let us understand, 
 is of things not partially but wholly different. 
 
 Theaet. Things utterly different cannot possibly have a 
 quality or anything else the same. 
 
 Soc. Must we confess that these things are therefore un- 
 like? 
 
 Theaet. I should say so. 
 
 Soc. Suppose that a thing happened to become like or unlike 
 itself or another thing, shall we say that what is made like be- 
 comes the same, and what unlike different? 
 
 Theaet. We must. 
 
 Soc. We said before, did we not, that the active elements 
 were many and infinite, and likewise the passive elements? 
 
 Theaet. Yes. 
 
 Soc. And if a thing combines with different things, the pro- 
 ducts will be different? 
 
 Theaet. Surely. 
 
 Soc. Let us apply this to you or me or anything, Socrates 
 sick and Socrates well, for example. Shall we say that these 
 are like or unlike? 
 
 Theaet. Am I to take Socrates sick as one separate whole, 
 and Socrates well as another? 
 
 Soc. You understand exactly; that is what I mean. 
 
 Theaet. They are unlike doubtless. 
 
 Soc. And different because unlike? 
 
 Theaet. Necessarily. 
 
 Soc. And will you say the same of Socrates asleep or in the 
 other states we mentioned? 
 
 Theaet. I would. 
 
 Soc. Then would I not be affected by any active element in 
 nature differently in sickness and in health? 
 
 Theaet. How could it be otherwise? 
 
 Soc. Would not the active element and I, the patient, pro- 
 duce a different result in each case? 
 
 Theaet. Certainly.
 
 PLATO'S THEAETETUS 21 
 
 Soc. The wine I drink when I am in health appears to me 
 sweet and pleasant? 
 
 Theaet. Yes. 
 
 Soc. It follows from our previous admissions that the active 
 and passive elements, when they unite, produce sweetness and 
 the sensation of sweetness. The sensation arising from the 
 patient renders the tongue percipient, and sweetness moving in 
 the wine and arising from it meets the healthy tongue, and 
 causes the wine both to be and to appear sweet. 
 
 Theaet, That is the consequence of what we formerly ad- 
 mitted. 
 
 Soc. But when-I am sick, does not the object affect a person 
 who, because unlike, is really different? 
 
 Theaet. Yes. 
 
 Soc. In that case Socrates and the drinking of the wine pro- 
 duce a different result, the sensation of bitterness in the tongue 
 and bitterness moving in the wine. The wine becomes not 
 bitterness but bitter, and I become not perception but per- 
 ceiving. 
 
 Theaet. Certainly. 
 
 Soc. There is no other thing, from which I shall ever receive 
 the same perception. The perception of different things is 
 different, and makes him, who perceives, of another nature and 
 another man. Nor does the object, which affects me, produce 
 the same result and become the same object, when it comes into 
 contact with another person. When objects produce different 
 results in contact with different subjects, they become of an- 
 other nature. 
 
 Theaet. It is true. 
 
 Soc. The object and I will not become what we are inde- 
 pendently of each other. 
 
 Theaet. By no means. 
 
 Soc. I must become percipient of something when I perceive, 
 for it is impossible in perceiving to perceive nothing. And when 
 the object becomes sweet or bitter or something else, it must do 
 so for some one, since to become sweet and yet sweet for no- 
 body is not possible.
 
 22 SOCRATES 
 
 Theaet. Assuredly not. 
 
 Soc. We must conclude that the object and I are or become 
 only one for the other. Necessity couples us to each other, but 
 does not couple our joint existence to any other thing or even 
 to ourselves. Each is bound simply to the other. Accordingly 
 when a thing is said to be or become, it must be spoken of as for 
 or of or in regard to something. The argument, which we have 
 traversed, points out that no one must say, or permit anyone 
 else to say, that' any thing is or becomes wholly of itself (avro 
 
 J 5 * "\ 
 
 <f> aVTOVJ. 
 
 Theaet. No, by no means, Socrates. 
 
 Soc. When anything, which affects me, exists for me and no 
 other person, is it not perceived by me and no other? 
 
 Theaet. That is evident. 
 
 Soc. Then my sensation is true for me since it is inseparable 
 from my existence. As Protagoras says, I am judge both of the 
 existence of what is for me and the non-existence of what is not. 
 
 Theaet. That seems to be the case. 
 
 Soc. If I am infallible and sure-footed in my judgments con- 
 cerning being (ra ovra) and becoming (ra yiyvoneva) , how can 
 I fail to know that of which I am the percipient (OMT^T^S)? 
 
 Theaet. Not in any way. 
 
 Soc. Right noble, then, was your decision that knowledge 
 was nothing else than perception. Homer and Heraclitus with 
 their crew, who say that all things flow and are in a state of 
 motion, and the all-wise Protagoras with his view that man is 
 the measure of all things, and Theaetetus, who concludes from 
 these theories that knowledge is sensation, are all of one accord. 
 Is that not true, O Theaetetus? Shall we call this result the 
 young child at whose birth I have assisted? Or what do you 
 say? 
 
 Theaet. It must be so, Socrates. 
 
 Steph. iS4b. 
 
 Soc. Once again, Theaetetus, address yourself to our former 
 inquiry. You answered that knowledge was sensible percep- 
 tion, did you not?
 
 PLATO'S THEAETETUS 23 
 
 Theaet. Yes. 
 
 Soc. If some one were to put this question to you, With what 
 does a man see white and black colours and with what does he 
 hear high and low tones? you would say, I think, with his eyes 
 and ears. 
 
 Theaet. I should. 
 
 Soc. To handle names and terms freely and without critical 
 minuteness is often a mark of wide culture, and though the 
 opposite is as a rule churlish, it is sometimes, as in the present 
 instance, a necessity. For I must indicate a want of exactness 
 in this very answer. Reflect, is it more correct to say that it 
 is with the eyes (b$6a\nol<i) that we see or through them (Si 1 
 6(j)6a\n,a)v) , and that it is with the ears or through them that 
 we hear? 
 
 Theaet. I think 'through' is better, Socrates. 
 
 Soc. Surely, for it would be a singular thing, my lad, if each 
 of us was, as it were, a wooden horse, and within us were seated 
 many separate senses, since manifestly these senses unite into 
 one nature (ISea), call it the soul or what you will; and it is 
 with this central form through the organs of sense that we per- 
 ceive sensible objects. 
 
 Theaet. I agree with your view ; the contrary would indeed be 
 singular. 
 
 Soc. I am precise with you, in order to find out if it is with 
 one and the same part of ourselves that we have various im- 
 pressions, although at the same time through different facul- 
 ties. Would you, if you were asked, refer all our impressions to 
 the body? But perhaps you would answer better without my 
 interference. Tell me, then, do you assign the faculties, through 
 which you perceive hot and hard and light and sweet, to the 
 body or to something else? 
 
 Theaet. To the body. 
 
 Soc. And would you be willing to allow that what you per- 
 ceive through one faculty (Svvafus) you cannot perceive 
 through another? You cannot, that is, hear through the eye 
 or see through the ear? 
 
 Theaet. I grant that readily.
 
 24 SOCRATES 
 
 Soc. If you make a judgment common to the two organs 
 (opyava), you cannot perceive it through either of them. 
 
 Theaet. Certainly not. 
 
 Soc. In the case of sound and colour you may surely decide 
 that they both are. 
 
 Theaet. Surely. 
 
 Soc. Is not each different (erepov) from the other and the 
 same (ravrdv) with itself? 
 
 Theaet. No doubt. 
 
 Soc. They are two and each is one? 
 
 Theaet. I grant that also. 
 
 Soc. You would be able to observe whether they are like or 
 unlike each other? 
 
 Theaet. Probably. 
 
 Soc. Through what do you make these several judgments? 
 For it is not possible either through hearing or sight to get any- 
 thing common to the two (TO KOIVOV). Let us take an illustra- 
 tion. Suppose it to be a sensible question to ask whether you 
 judge colours and sounds to be saline or not, you would be able 
 to say what faculty you would use in order to decide, and this 
 faculty would be not sight or hearing but some other. 
 
 Theaet. Another of course, the faculty of taste. 
 
 Soc. That is well said. And what faculty will reveal to you 
 the common elements not only of sensible qualities, but of all 
 things, those elements, I mean, which you call being (TO ea-nv) 
 and not being (TO OVK ea-riv) and the others, about which we 
 were speaking a moment ago? To what organ will you attribute 
 our perception of each of these? 
 
 Theaet. You allude to being (ovcria) and not being (TO pr) 
 elvai), likeness (o/iotoV???) and unlikeness, the same (TO ravTov) 
 and the other (TO e-rep^v), and unity (ev) also, and other 
 numbers applicable to things, and you evidently wish to know 
 through what bodilymstrument the soul perceives odd (irepiT-rov} 
 and even (apnov) and all that is akin to them. 
 
 Soc. You follow me surpassingly well, Theaetetus; that is 
 just what I want. 
 
 Theaet. Verily, Socrates, I cannot tell what to say, if not that
 
 PLATO'S THEAETETUS 25 
 
 these things unlike sensible objects seem to need no special 
 organ, but that the soul contemplates the common elements 
 (TO, Koiva) of all things through itself (&' avrrpi) . 
 
 Soc. You are beautiful, Theaetetus, and not ill-favoured, as 
 Theodorus said, for he who says beautiful things, is beautiful and 
 good. And not only are you beautiful but you have done well in 
 delivering me from a long harangue, if you are satisfied that 
 some things the soul contemplates through itself and others 
 through the bodily faculties. For that was my opinion too, and 
 I was anxious for you to agree with me. 
 
 Theaet. I am convinced of the truth of that. 
 
 Soc. On which side would you place being, which is in a 
 unique way associated with all things? 
 
 Theaet. I would place it amongst those things, which the soul 
 strives to grasp of itself (xaO' avrtjv) . 
 
 Soc. And would you place there the like and unlike, the 
 same and the other? 
 
 Theaet. Yes. 
 
 Soc. And what of the noble and base, good and evil? 
 
 Theaet. In this case quite specially the soul views the essence 
 (ova-ia) of each in relation to its opposite, contrasting within 
 itself the past and present with the future. 
 
 Soc. Stay a moment. Does the soul not perceive the hard- 
 ness of a hard object through the touch, and in the same way 
 the softness of a soft object? 
 
 Theaet. Yes. 
 
 Soc. But the essence and existence of these, and the opposi- 
 tion of each to the other, and the essence of this opposition, the 
 soul itself judges, bringing them all together and passing them 
 in review. 
 
 Theaet. Certainly. 
 
 Soc. Men and animals from their -very birth perceive by 
 nature those feelings (iraOri^ara) which reach the soul through 
 the body; but reflections (avaXoyia-paTa) on the essence of these 
 and on their use come to those who have them only after effort 
 and with the lapse of years through education and a wide ex- 
 perience.
 
 26 SOCRATES 
 
 Theaet. That is very true. 
 
 Soc. Is it possible to gain truth, if we have no hold of being? 
 
 Theaet. Impossible. 
 
 Soc. If we fall short of the truth of anything, can we be said 
 to know it? 
 
 Theaet. By no means, Socrates. 
 
 Soc. Then in feelings there is no knowledge but only in rea- 
 sonings (a-v\\oyio-fjioi) upon them, for in reasonings it is pos- 
 sible to touch being and truth, but in feelings it is impossible. 
 
 Theaet. That is evident. 
 
 Soc. Do you call reasonings and feelings, the same, when 
 they differ so widely? 
 
 Theaet. That would hardly be just. 
 
 Soc. What name do you give to seeing, hearing, smelling, 
 being cold and being warm? 
 
 Theaet. Perceiving, I would call them. I have no other 
 name. 
 
 Soc. Perception then, you say, covers them all? 
 
 Theaet. It must. 
 
 Soc. And this has no share in truth, because it lays not hold 
 on being. 
 
 Theaet. None. 
 
 Soc. Then it has no share in knowledge. 
 
 Theaet. No. 
 
 Soc. Then, Theaetetus, sensible perception and knowledge 
 will never be the same. 
 
 Theaet. Clearly not, Socrates; indeed it is now quite evident 
 that knowledge and sensation are different. *
 
 PLATO 
 
 (427-347) 
 
 THE REPUBLIC 
 
 Translated from the Greek* by 
 
 JOHN LLEWELYN DAVIES AND 
 DAVID JAMES VAUGHAN 
 
 BOOK IV. THE THREE FACULTIES OF 
 
 THE SOUL 
 SOCRATES GLAUCON 
 
 Steph. 435- 
 
 I PROCEEDED to ask: When two things, a greater and a less, 
 are called by a common name, are they, in so far as the common 
 name applies, unlike or like? 
 
 Like. 
 
 Then a just man will not differ from a just state, so far as 
 the idea of justice is involved, but the two will be like. 
 
 They will. 
 
 Well, but we resolved that a state was just, when the three 
 classes of characters present in it were severally occupied in 
 doing their proper work: and that it was temperate, and brave, 
 and wise, in consequence of certain affections and conditions of 
 these same classes. 
 
 True. 
 
 Then, my friend, we shall also adjudge, in the case of the 
 individual man, that, supposing him to possess in his soul the 
 same generic parts, he is rightly entitled to the same names as 
 the state, in virtue of affections of these parts identical with 
 those of the classes in the state. 
 It must inevitably be so. 
 
 * From nxdrwj'os HoXiTefa. Reprinted from The Republic of Plato, translated 
 by J. L. Davies and D. J. Vaughan, Cambridge, 1852, etc.
 
 28 PLATO 
 
 Once more then, my excellent friend, we have stumbled on 
 an easy question concerning the nature of the soul, namely, 
 whether it contains these three generic parts or not. 
 
 Not so very easy a question, I think: but perhaps, Socrates, 
 the common saying is true, that the beautiful is difficult. 
 
 It would appear so; and I tell you plainly, Glaucon, that in 
 my opinion we shall never attain to exact truth on this subject, 
 by such methods as we are employing in our present discussion. 
 However, the path that leads to that goal is too long and toil- 
 some; and I dare say we may arrive at the truth by our present 
 methods, in a manner not unworthy of our former arguments 
 and speculations. 
 
 Shall we not be content with that? For my part it would 
 satisfy me for the present. 
 
 Well, certainly it will be quite enough for me. 
 
 Do not flag then, but proceed with the inquiry. 
 
 Tell me then, I continued, can we possibly refuse to admit 
 that there exist in each of us the same generic parts and char- 
 acteristics as are found in the state? For I presume the state 
 has not received them from any other source. It would be 
 ridiculous to imagine that the presence of the spirited element 
 in cities is not to be traced to individuals, wherever this char- 
 acter is imputed to the people, as it is to the natives of Thrace, 
 and Scythia, and generally speaking, of the northern countries; 
 or the love of knowledge, which would be chiefly attributed to 
 our own country; or the love of riches, which people would es- 
 pecially connect with the Phoenicians and the Egyptians. 
 
 Certainly. 
 
 This then is a fact so far, and one which it is not difficult to 
 apprehend. 
 
 No, it is not. 
 
 But here begins a difficulty. Are all our actions alike per- 
 formed by the one predominant faculty, or are there three fac- 
 ulties operating severally in our different actions? Do we learn 
 with one internal faculty, and become angry with another, and 
 with a third feel desire for all the pleasures connected with eat- 
 ing and drinking, and the propagation of the species; or upon
 
 THE REPUBLIC 29 
 
 every impulse to action, do we perform these several operations 
 with the whole soul? The difficulty will consist in settling these 
 points in a satisfactory manner. 
 
 I think so too. 
 
 Let us try therefore the following plan, in order to ascertain 
 whether the faculties engaged are distinct or identical. 
 
 What is your plan? 
 
 It is manifest that the same thing cannot do two opposite 
 things, or be in two opposite states, in the same part of it, and 
 with reference to the same object; so that where we find these 
 phenomena occurring, we shall know that the subjects of them 
 are not identical, but more than one. 
 
 Very well. 
 
 Now consider what I say. 
 
 Speak on. 
 
 Is it possible for the same thing to be at the same time, and 
 in the same part of it, at rest and in motion? 
 
 Certainly not. 
 
 Let us come to a still more exact understanding, lest we should 
 chance to differ as we proceed. If it were said of a man who is 
 standing still, but moving his hands and his head, that the same 
 individual is at the same time at rest and in motion, we should 
 not, I imagine, allow this to be a correct way of speaking, but 
 should say, that part of the man is at rest, and part in motion : 
 should we not? 
 
 We should. 
 
 And if the objector should indulge in yet further pleasan- 
 tries, so far refining as to say, that at any rate a top is wholly 
 at rest and in motion at the same time, when it spins with its 
 peg fixed on a given spot, or that anything else revolving in the 
 same place, is an instance of the same thing, we should reject 
 his illustration, because in such cases the things are not both 
 stationary and in motion in respect of the same parts of them ; 
 and we should reply, that they contain an axis and a circum- 
 ference, and that in respect of the axis they are stationary, inas- 
 much as they do not lean to any side; but in respect of the cir- 
 cumference they are moving round and round : but if, while the
 
 30 PLATO 
 
 rotatory motion continues, the axis at the same time inclines to 
 the right or to the left, forwards or backwards, then they can- 
 not be said in any sense to be at rest. 
 
 That is true. 
 
 Then no objection of that kind will alarm us, or tend at all to 
 convince us that it is ever possible for one and the same thing, 
 at the same time, in the same part of it, and relatively to the 
 same object, to be acted upon in two opposite ways, or to be 
 two opposite things, or to produce two opposite effects. 
 
 I can answer for myself. 
 
 However, that we may not be compelled to spend time in dis- 
 cussing all such objections, and convincing ourselves that they 
 are unsound, let us assume this to be the fact, and proceed 
 forwards, with the understanding that, if ever we take a differ- 
 ent view of this matter, all the conclusions founded on this as- 
 sumption will fall to the ground. 
 
 Yes, that will be the best way. 
 
 Well then, I continued, would you place assent and dissent, 
 the seeking after an object and the refusal of it, attraction 
 and repulsion, and the like, in the class of mutual opposites? 
 Whether they be active or passive processes will not affect the 
 question. 
 
 Yes, I should. 
 
 Well, would you not, without exception, include hunger and 
 thirst, and the desires generally, and likewise willing and wish- 
 ing, somewhere under the former of those general terms just 
 mentioned? For instance, would you not say that the mind of a 
 man under the influence of desire always either seeks after the 
 object of desire, or attracts to itself that which it wishes to have ; 
 or again, so far as it wills the possession of anything, it assents 
 inwardly thereto, as though it were asked a question, longing for 
 the accomplishment of its wish? 
 
 I should. 
 
 Again: shall we not class disinclination, unwillingness, and 
 dislike, under the head of mental rejection and repulsion, and of 
 general terms wholly opposed to the former? 
 
 Unquestionably.
 
 THE REPUBLIC 31 
 
 This being the case, shall we say that desires form a class, 
 the most marked of which are what we call thirst and hunger? 
 
 We shall. 
 
 The one being a desire of drink, and the other of food? 
 
 Yes. 
 
 Can thirst then, so far as it is thirst, be an internal desire 
 of anything more than drink? That is to say, is thirst, as such, 
 a thirst for hot drink or cold, for much or little, or, in one word, 
 for any particular kind of drink? Or, will it not rather be true 
 that, if there be heat combined with the thirst, the desire of 
 cold drink will be superadded to it, and if there be cold, of hot 
 drink; and if owing to the presence of muchness, the thirst be 
 great, the desire of much will be added, and if little, the desire 
 of little: but that thirst in itself cannot be a desire of anything 
 else than its natural object, which is simple drink, or again, 
 hunger, of anything but food? 
 
 You are right, he replied; every desire in itself has to do with 
 its natural object in its simply abstract form, but the accesso- 
 ries of the desire determine the quality of the object. 
 
 Let not any one, I proceeded, for want of consideration on 
 our part, disturb us by the objection, that no one desires drink 
 simply, but good drink, nor food simply, but good food; be- 
 cause, since all desire good things, if thirst is a desire, it must 
 be a desire of something good, whether that something, which 
 is its object, be drink or anything else; an argument which 
 applies to all the desires. 
 
 True, there might seem to be something in the objection. 
 
 Recollect, however, that in the case of all essentially correla- 
 tive terms, when the first member of the relation is qualified, 
 the second is also qualified, if I am not mistaken; when the 
 first is abstract, the second is also abstract. 
 
 I do not understand you. 
 
 Do you not understand that 'greater' is a relative term, im- 
 plying another term? 
 
 Certainly. 
 
 It implies a 'less,' does it not? 
 
 Yes.
 
 32 PLATO 
 
 And a much greater implies a much less, does it not? 
 
 Yes. 
 
 Does a once greater also imply a once less, and a future 
 greater a future less? 
 
 Inevitably. 
 
 Does not the same reasoning apply to the correlative terms, 
 'more' and 'fewer,' 'double' and 'half/ and all relations of 
 quantity; also to the terms, 'heavier' and 'lighter,' 'quicker' 
 and 'slower;' and likewise to 'cold' and 'hot,' and all similar 
 epithets? 
 
 Certainly it does. 
 
 But how is it with the various branches of scientific know- 
 ledge? Does not the same principle hold? That is, knowledge 
 in the abstract is knowledge simply of the knowable, or of what- 
 ever that be called which is the object of knowledge; but a par- 
 ticular science, of a particular kind, has a particular object of a 
 particular kind. To explain my meaning: as soon as a science 
 of the construction of houses arose, was it not distinguished 
 from other sciences, and therefore called the science of building? 
 
 Undoubtedly. 
 
 And is it not because it is of a particular character, which no 
 other science possesses? 
 
 Yes. 
 
 And is not its particular character derived from the particu- 
 lar character of its object? and may we not say the same of all 
 the other arts and sciences? 
 
 We may. 
 
 This then you are to regard as having been my meaning 
 before; provided, that is, you now understand that in the case 
 of all correlative terms, if the first member of the relation is 
 abstract, the second is also abstract; if the second is qualified, 
 the first is also qualified. I do not mean to say that the qualities 
 of the two are identical, as for instance, that the science of 
 health is healthy, and the science of disease diseased; or that 
 the science of evil things is evil, and of good things good : but as 
 soon as science, instead of limiting itself to the abstract object 
 of science, became related to a particular kind of object, namely,
 
 THE REPUBLIC 33 
 
 in the present case, the conditions of health and disease, the re- 
 sult was that the science also came to be qualified in a certain 
 manner, so that it was no longer called simply science, but, by 
 the addition of a qualifying epithet, medical science. 
 
 I understand, and I think what you say is true. 
 
 To recur to the case of thirst, I continued, do you not con- 
 sider this to be one of the things whose nature it is to have an 
 object correlative with themselves, assuming that there is such 
 a thing as thirst? 
 
 I do, and its object is drink. 
 
 Then, for any particular kind of drink there is a particular 
 kind of thirst; but thirst in the abstract is neither for much 
 drink, nor for little, neither for good drink nor for bad, nor, in 
 one word, for any kind of drink, but simply and absolutely 
 thirst for drink, is it not? 
 
 Most decidedly so. 
 
 Then the soul of a thirsty man, in so far as he is thirsty, has 
 no other wish than to drink ; but this it desires, and towards this 
 it is impelled. 
 
 Clearly so. 
 
 Therefore, whenever anything pulls back a soul that is under 
 the influence of thirst, it will be something in the soul distinct 
 from the principle which thirsts, and which drives it like a beast 
 to drink: for we hold it to be impossible that the same thing 
 should, at the same time, with the same part of itself, in refer- 
 ence to the same object, be doing two opposite things. , 
 
 Certainly it is. 
 
 Just as, I imagine, it would not be right to say of the bowman, 
 that his hands are at the same time drawing the bow towards 
 him, and pushing it from him; the fact being, that one of his 
 hands pushes it from him, and the other pulls it to him. 
 
 Precisely so. 
 
 Now, can we say that people sometimes are thirsty, and yet 
 do not wish to drink? 
 
 Yes, certainly; it often happens to many people. 
 
 What then can one say of them, except that their soul con- 
 tains one principle which commands, and another which for-
 
 34 PLATO 
 
 bids them to drink, the latter being distinct from and stronger 
 than the former? 
 
 That is my opinion. 
 
 Whenever the authority which forbids such indulgences 
 grows up in the soul, is it not engendered there by reasoning; 
 while the powers which lead and draw the mind towards them, 
 owe their presence to passive and morbid states? 
 
 It would appear so. 
 
 Then we shall have reasonable grounds for assuming that 
 these are two principles distinct one from the other, and for 
 giving to that part of the soul with which it reasons the title of 
 the rational principle, and to that part with which it loves and 
 hungers and thirsts, and experiences the flutter of the other de- 
 sires, the title of the irrational and concupiscent principle, the 
 ally of sundry indulgences and pleasures. 
 
 Yes, he replied : it will not be unreasonable to think so. 
 
 Let us consider it settled, then, that these two specific parts 
 exist in the soul. But now, will spirit, or that by which we feel 
 indignant, constitute a third distinct part? If not, with which 
 of the two former has it a natural affinity? 
 
 Perhaps with the concupiscent principle. 
 
 But I was once told a story, which I can quite believe, to the 
 effect, that Leontius, the son of Aglaion, as he was walking up 
 from the Piraeus, and approaching the northern wall from the 
 outside, observed some dead bodies on the ground, and the 
 executioner standing by them. He immediately felt a desire to 
 look at them, but at the same time loathing the thought he 
 tried to divert himself from it. For some time he struggled 
 with himself, and covered his eyes, till at length, over-mastered 
 by the desire, he opened his eyes wide with his fingers, and run- 
 ning up to the bodies, exclaimed, 'There! you wretches! gaze 
 your fill at the beautiful spectacle!' 
 
 I have heard the anecdote too. 
 
 This story, however, indicates that anger sometimes fights 
 against the desires, which implies that they are two distinct 
 principles. 
 
 True, it does indicate that.
 
 THE REPUBLIC 35 
 
 And do we not often observe in other cases that when a man 
 is overpowered by his desires against the dictates of his reason, 
 he reviles himself, and resents the violence thus exerted within 
 him, and that, in this struggle of contending parties, the spirit 
 sides with the reason? But that it should make common cause 
 with the desires, when the reason pronounces that they ought 
 not to act against itself, is a thing which I suppose you will not 
 profess to have experienced yourself, nor yet, I imagine, have 
 you ever noticed it in any one else. 
 
 No, I am sure I have not. 
 
 Well, and when any one thinks he is in the wrong, is he not, 
 in proportion to the nobleness of his character, so much the less 
 able to be angry at being made to suffer hunger or cold or any 
 similar pain at the hands of him whom he thinks justified in so 
 treating him; his spirit, as I describe it, refusing to be roused 
 against his punisher? 
 
 True. 
 
 On the other hand, when any one thinks he is wronged, does 
 he not instantly boil and chafe, and enlist himself on the side of 
 what he thinks to be justice; and whatever extremities of hun- 
 ger and cold and the like he may have to suffer, does he not 
 endure till he conquers, never ceasing from his noble efforts, 
 till he has either gained his point, or perished in the attempt, 
 or been recalled and calmed by the voice of reason within, as a 
 dog is called off by a shepherd? 
 
 Yes, he replied, the case answers very closely to your de- 
 scription; and in fact, in our city we made the auxiliaries, like 
 sheep-dogs, subject to the rulers, who are as it were the shep- 
 herds of the state. 
 
 You rightly understand my meaning. But try whether you 
 also apprehend my next observation. 
 
 What is it? 
 
 That our recent view of the spirited principle is exactly 
 reversed. Then we thought it had something of the concupis- 
 cent character, but now we say that, far from this being the 
 case, it much more readily takes arms on the side of the rational 
 principle in the party conflict of the soul.
 
 3 6 PLATO 
 
 Decidedly it does. 
 
 Is it then distinct from this principle also; or is it only a mod- 
 ification of it, thus making two instead of three distinct princi- 
 ples in the soul, namely, the rational and the concupiscent? 
 Or ought we to say that, as the state was held together by three 
 great classes, the producing class, the auxiliary, and the delib- 
 erative, so also in the soul the spirited principle constitutes a 
 third element, the natural ally of the rational principle, if it be 
 not corrupted by evil training? 
 
 It must be a third, he replied. 
 
 Yes, I continued; if it shall appear to be distinct from the ra- 
 tional principle, as we found it different from the concupiscent. 
 
 Nay, that will easily appear. For even in little children any 
 one may see this, that from their very birth they have plenty 
 of spirit, whereas reason is a principle to which most men only 
 attain after many years, and some, in my opinion, never. 
 
 Upon my word you have well said. In brute beasts also one 
 may see what you describe exemplified. And besides, that pas- 
 sage in Homer, which we quoted on a former occasion, will sup- 
 port our view: 
 'Smiting his breast, to his heart thus spake he in accents of chiding.' 
 
 For in this line Homer has distinctly made a difference between 
 the two principles, representing that which had considered the 
 good or the evil of the action as rebuking that which was in- 
 dulging in unreflecting resentment. 
 
 You are perfectly right. 
 
 Here then, I proceeded, after a hard struggle, we have, though 
 with difficulty, reached the land; and we are pretty well satis- 
 fied that there are corresponding divisions, equal in number, 
 in a state, and in the soul of every individual. 
 
 BOOK VI. THE CORRELATION OF THE FACULTIES 
 
 Steph. 508 D. 
 
 JUST in the same way understand the condition of the soul 
 to be as follows. Whenever it has fastened upon an object, over 
 which truth and real existence are shining, it seizes that object
 
 THE REPUBLIC 37 
 
 by an act of reason, and knows it, and thus proves itself to be 
 possessed of reason: but whenever it has fixed upon objects 
 that are blent with darkness, the world of birth and death, 
 then it rests in opinion, and its sight grows dim, as its opinions 
 shift backwards and forwards, and it has the appearance of 
 being destitute of reason. 
 
 True it has. 
 
 Now, this power, which supplies the objects of real know- 
 ledge with the truth that is in them, and which renders to him 
 who knows the faculty of knowing them, you must consider to 
 be the essential form of good, and you must regard it as the 
 origin of science, and of truth, so far as the latter comes within 
 the range of knowledge; and though knowledge and truth are 
 both very beautiful things, you will be right in looking upon 
 good as something distinct from them, and even more beautiful. 
 And just so, in the analogous case, it is right to regard light and 
 vision so resembling the sun, but wrong to identify them with 
 the sun; so, in the case of science and truth, it is right to regard 
 both of them as resembling good, but wrong to identify either 
 of them with good; because, on the contrary, the quality of 
 good ought to have a still higher value set upon it. 
 
 That implies an irrepressible beauty, if it not only is the 
 source of science and truth, but also surpasses them in beauty; 
 for, I presume, you do not mean by it pleasure. 
 
 Hush ! I exclaimed, not a word of that. But you had better 
 examine the illustration further, as follows. 
 
 Shew me how. 
 
 I think you will admit that the sun ministers to visible 
 objects, not only the faculty of being seen, but also their vital- 
 ity, growth, and nutriment, though it is not itself equivalent 
 to vitality. 
 
 Of course it is not. 
 
 Then admit that, in like manner, the objects of knowledge 
 not only derive from the good the gift of being known, but are 
 further endowed by it with a real and essential existence; though 
 the good, far from being identical with real existence, actually 
 transcends it in dignity and power.
 
 38 PLATO 
 
 Hereupon Glaucon exclaimed with a very amusing air, Good 
 heavens! what a miraculous superiority! 
 
 Well, I said, you are a person to blame, because you compel 
 me to state my opinions on the subject. 
 
 Nay, let me entreat you not to stop, till you have at all events 
 gone over again your similitude of the sun, if you are leaving 
 anything out. 
 
 Well, to say the truth, I am leaving out a great deal. 
 
 Then pray do not omit even a trifle. 
 
 I fancy I shall leave much unsaid ; however, if I can help it 
 under the circumstances, I will not intentionally make any 
 omission. 
 
 Pray do not. 
 
 Now understand that, according to us, there are two powers 
 reigning, one over an intellectual, and the other over a visible 
 region and class of objects; if I were to use the term ' firma- 
 ment,' you might think I was playing on the word. Well then, 
 are you in possession of these as two kinds, one visible, the 
 other intellectual? 
 
 Yes, I am. 
 
 Suppose you take a line divided into two unequal parts, - 
 one to represent the visible class of objects, the other the intel- 
 lectual, and divide each part again into two segments on the 
 same scale. Then, if you make the lengths of the segments re- 
 present degrees of distinctness or indistinctness, one of the two 
 segments of the part which stands for the visible world will 
 represent all images: meaning by images, first of all, shad- 
 ows; and, in the next place, reflections in water, and in close- 
 grained, smooth, bright substances, and everything of the 
 kind, if you understand me. 
 
 Yes, I do understand. 
 
 Let the other segment stand for the real objects correspond- 
 ing to these images, namely, the animals about us, and the 
 whole world of nature and of art. 
 
 Very good. 
 
 Would you also consent to say that, with reference tp this 
 class, there is, in point of truth and untruthfulness, the same
 
 THE REPUBLIC 39 
 
 distinction between the copy and the original, that there is be- 
 tween what is matter of opinion and what is matter of know- 
 ledge? 
 
 Certainly I should. 
 
 Then let us proceed to consider how we must divide that part 
 of the whole line which represents the intellectual world. 
 
 How must we do it? 
 
 Thus: one segment of it will represent what the soul is com- 
 pelled to investigate by the aid of the segments of the other 
 part, which it employs as images, starting from hypotheses, 
 and travelling not to a first principle, but to a conclusion. The 
 other segment will represent the objects of the soul, as it makes 
 its way from an hypothesis to a first principle which is not hy- 
 pothetical, unaided by those images which the former division 
 employs, and shaping its journey by the sole help of real essen- 
 tial forms. 
 
 I have not understood your description so well as I could 
 wish. 
 
 Then we will try again. You will understand me more easily 
 when I have made some previous observations. I think you 
 know that the students of subjects like geometry and calcula- 
 tion, assume by way of materials, in each investigation, all 
 odd and even numbers, figures, three kinds of angles, and 
 other similar data. These things they are supposed to know, 
 and having adopted them as hypotheses, they decline to 
 give any account of them, either to themselves or to others, 
 on the assumption that they are self-evident; and, making 
 these their starting point, they proceed to travel through the 
 remainder of the subject, and arrive at last, with perfect 
 unanimity, at that which they have proposed as the object of 
 investigation. 
 
 I am perfectly aware of the fact, he replied. 
 
 Then you also know that they summon to their aid visible 
 forms, and discourse about them, though their thoughts are 
 busy not with these forms, but with their originals, and though 
 they discourse not with a view to the particular square and 
 diameter which they draw, but with a view to the absolute
 
 4 o PLATO 
 
 square and the absolute diameter, and so on. For while they 
 employ by way of images those figures and diagrams afore- 
 said, which again have their shadows and images in water, they 
 are really endeavoring to behold those abstractions which a per- 
 son can only see with the eye of thought. 
 
 True. 
 
 This, then, was the class of things which I called intellectual; 
 but I said that the soul is constrained to employ hypotheses 
 while engaged in the investigation of them, not travelling 
 to a first principle, (because it is unable to step out of, and 
 mount above, its hypotheses,) but using, as images, just the 
 copies that are presented by things below, which copies, as 
 compared with the originals, are vulgarly esteemed distinct and 
 valued accordingly. 
 
 I understand you to be speaking of the subject-matter of the 
 various branches of geometry and the kindred arts. 
 
 Again, by the second segment of the intellectual world 
 understand me to mean all that the mere reasoning process 
 apprehends by the force of dialectic, when it avails itself of 
 hypotheses not as first principles, but as genuine hypotheses, 
 that is to say, as stepping-stones and impulses, whereby it may 
 force its way up to something that is not hypothetical, and ar- 
 rive at the first principle of everything, and seize it in its grasp; 
 which done, it turns round, and takes hold of that which takes 
 hold of this first principle, till at last it comes down to a conclu- 
 sion, calling in the aid of no sensible object whatever, but sim- 
 ply employing abstract, self-subsisting forms, and terminating 
 in the same. 
 
 I do not understand you so well as I could wish, for I believe 
 you to be describing an arduous task; but at any rate I under- 
 stand that you wish to declare distinctly, that the field of real 
 existence and pure intellect, as contemplated by the science of 
 dialectic, is more certain than the field investigated by what 
 are called the arts, in which hypotheses constitute first princi- 
 ples, which the students are compelled, it is true, to contem- 
 plate with the mind and not with the senses; but, at the same 
 time, as they do not come back, in the course of inquiry, to a
 
 THE REPUBLIC 41 
 
 first principle, but push on from hypothetical premises, you 
 think that they do not exercise pure reason on the questions 
 that engage them, although taken in connexion with a first 
 principle these questions come within the domain of the pure 
 reason. And I believe you apply the term understanding, not 
 pure reason, to the mental habit of such people as geometri- 
 cians, regarding understanding as something intermediate 
 between opinion and pure reason. 
 
 You have taken in my meaning most satisfactorily; and I beg 
 you will accept these four mental states, as corresponding to 
 the four segments, namely pure reason corresponding to the 
 highest, understanding to the second, belief to the third, and 
 conjecture to the last; and pray arrange them in gradation, 
 and believe them to partake of distinctness in a degree corre- 
 sponding to the truth of their respective objects. 
 
 I understand you, said he. I quite agree with you, and wjll 
 arrange them as you desire. 
 
 BOOK X. THE SOUL'S IMMORTALITY 
 
 Steph. 609. 
 
 AGAIN: do you maintain that everything has its evil, and its 
 good? Do you say, for example, that the eyes are liable to the 
 evil of ophthalmia, the entire body to disease, corn to mildew, 
 timber to rot, copper and iron to rust, or, in other words, that 
 almost everything is liable to some connatural evil and malady? 
 
 I do. 
 
 And is it not the case that, whenever an object is attacked 
 by one of these maladies, it is impaired, and, in the end, com- 
 pletely broken up and destroyed by it? 
 
 Doubtless it is so. 
 
 Hence everything is destroyed by its own connatural evil 
 and vice; otherwise, if it be not destroyed by this, there is no- 
 thing else that can corrupt it. For that which is good will never 
 destroy anything, nor yet that which is neither good nor evil. 
 
 Of course not. 
 
 If then we can find among existing things one which is liable
 
 42 PLATO 
 
 to a particular evil, which can indeed mar it, but cannot break 
 it u"p or destroy it, shall we not be at once certain that a thing 
 so constituted can never perish? 
 
 That would be a reasonable conclusion. 
 
 Well, then, is not the soul liable to a malady which renders it 
 evil ? 
 
 Certainly it is; all those things which we were lately discuss- 
 ing, injustice, intemperance, cowardice, and ignorance, - 
 produce that result. 
 
 That being the case, does any one of these things bring about 
 the dissolution and destruction of the soul? Turn it over well 
 in your mind, that we may not be misled by supposing that, 
 when the crimes of the unjust and foolish man are found out, 
 he is destroyed by his injustice, which is a depraved state of the 
 soul. No, consider the case thus. The depravity of the body, 
 that is to say, disease, wastes and destroys the body, and re- 
 duces it to a state in which it ceases to be a body; and all the 
 things, which we named just now, are brought by their own 
 proper vice, which corrupts them by its adhesion or indwelling, 
 to a state in which they cease to exist. I am right, am "1 not ? 
 
 Yes. 
 
 Then proceed to examine the soul on the same method. Is 
 it true that, when injustice and other vices reside in the soul, 
 they corrupt and wither it by contact or indwelling, until they 
 have brought it to death, and severed it from the body? 
 
 Certainly, they do not produce that effect. 
 
 Well but, on the other hand, it is irrational to suppose that 
 a thing can be destroyed by the depravity of another thing, 
 though it cannot be destroyed by its own. 
 
 True, it is irrational. 
 
 Yes it is, Glaucon; for you must remember that we do not 
 imagine that a body is to be destroyed by the proper depravity 
 of its food, whatever that may be, whether mouldiness or rot- 
 tenness or anything else. But if the depravity of the food itself 
 produces in the body a disorder proper to the body, we shall 
 assert that the body has been destroyed by its food remotely, 
 but by its own proper vice, or disease, immediately: and we
 
 THE REPUBLIC 43 
 
 shall always disclaim the notion that the body can be corrupted 
 by the depravity of its food, which is a different thing from the 
 body, that is to say, the notion that the body can be cor- 
 rupted by an alien evil, without the introduction of its own 
 native evil. 
 
 You are perfectly correct. 
 
 Then according to the same reasoning, I continued, unless 
 depravity of body introduces into the soul depravity of soul, 
 let us never suppose that the soul can be destroyed by an alien 
 evil without the presence of its own peculiar disease; for that 
 would be to suppose that one thing can be destroyed by the 
 evil of another thing. 
 
 That is a reasonable statement. 
 
 Well then, let us either refute this doctrine and point out 
 our mistake, or else, so long as it remains unrefuted, let us 
 never assert that a fever, or any other disease, or fatal vio- 
 lence, or even the act of cutting up the entire body into the 
 smallest possible pieces, can have any tendency to destroy the 
 soul, until it has been demonstrated, that, in consequence of 
 this treatment of the body, the soul itself becomes more unjust 
 and more unholy. For, so long as a thing is exempt from its own 
 proper evil, while an evil foreign to it appears in another sub- 
 ject, let us not allow it to be said that this thing, whether it be 
 a soul or anything else, is in danger of being destroyed. 
 
 Well, certainly no one will ever prove that the souls of the 
 dying become more unjust in consequence of death. 
 
 But in case any one should venture to encounter the argu- 
 ment, and to assert that the dying man becomes more depraved 
 and unjust, in order to save himself from being compelled to 
 admit that the soul is immortal, I suppose we shall infer that, 
 if the objector is right, injustice is as fatal as a disease to its 
 possessor ; and we shall expect those who catch this essentially 
 deadly disorder to die by its agency, quickly or slowly, accord- 
 ing to the violence of the attack; instead of finding, as we do at 
 present, that the unjust are put to death in consequence of their 
 injustice, by the agency of other people who punish them for 
 their crimes.
 
 44 PLATO 
 
 Then really, said he, injustice cannot be thought such a very 
 dreadful thing, if it is to be fatal to its owner; because in that 
 case it will be a release from evils. But I am inclined to think 
 that, on the contrary, we shall find that it kills other people 
 if it can, while it endows its possessor with peculiar vitality, 
 and with sleeplessness as well as vitality. So widely and per- 
 manently is it removed, to all appearance, from any tendency 
 to destroy its owner. 
 
 You say well, I replied. For surely when the soul cannot be 
 killed and destroyed by its own depravity and its own evil, 
 hardly will the evil, which is charged with the destruction of 
 another thing, destroy a soul or anything else, beyond its own 
 appropriate object. 
 
 Yes, hardly; at least that is the natural inference. 
 
 Hence, as it is destroyed by no evil at all, whether foreign 
 to it or its own, it is clear that the soul must be always existing, 
 and therefore immortal. 
 
 It must. 
 
 Well then, I continued, let us consider this proved. And, if 
 so, you understand that the souls that exist must be always the 
 same. For, if none be destroyed, they cannot become fewer. 
 Nor yet can they become more numerous; because if any class 
 of things immortal became more numerous, you know that 
 something mortal must have contributed to swell its numbers; 
 in which case, everything would finally be immortal. 
 
 True. 
 
 But reason will forbid our entertaining this opinion, which 
 we must therefore disavow. On the other hand, do not let us 
 imagine that the soul in its essential nature, and viewed by 
 itself, can possibly be fraught with abundance of variety, un- 
 likeness, and disagreement. 
 
 What do you mean? 
 
 A thing cannot easily be eternal, as we have just proved the 
 soul to be, if it is compounded of many parts, and if the mode 
 of composition employed is not the very best. 
 
 Probably it cannot.
 
 ARISTOTLE 
 
 (384-322) 
 
 PSYCHOLOGY 
 
 Translated from the * Greek by 
 WILLIAM ALEXANDER HAMMOND 
 
 BOOK II. THE FACULTIES OF THE SOUL 
 CHAPTER I. DEFINITION OF THE SOUL 
 
 41 2a 
 
 LET the foregoing f suffice as a discussion of the traditional 
 theories of the soul ; and now let us resume our subject from the 
 start, and attempt to determine the nature of the soul and its 
 most general definition. One class of realities we call 'sub- 
 stance.' This 'substance' may be regarded on the one hand as 
 matter, which in itself is no definite thing; on the other hand, 
 as form and idea, in terms of which definite individuality is 
 ascribed to a thing. A third meaning of substance is the com- 
 posite of matter and form. Matter is potentiality; form is 
 actuality or realization. The latter may be looked at in two 
 ways, either as complete realization, comparable with per- 
 fected knowledge, or as realization in process, comparable 
 with the activity of contemplation. The notion of substance 
 appears to be most generally employed in the sense of body, 
 and particularly of physical body; for this is the source of all 
 other bodies. Some physical bodies have, and others have not, 
 life. By life we understand an inherent principle of nutrition, 
 growth, and decay. So that every natural body endowed with 
 life would be substance, and substance in this composite sense. 
 
 * From 'ApumfXouj irepl faxy*. Reprinted from Aristotle's Psychology, A 
 Treatise on the Principle of Life, translated by W. A. Hammond, London, 
 Swan Sonnenschein & Co. Ltd. 1902. 
 
 t Supra, pp. s-ii.
 
 46 ARISTOTLE 
 
 The body, therefore, would not be soul, since body is of such 
 nature that life is an attribute of it. For body is not predicated 
 of something else, but is rather itself substrate and matter. 
 The soul must, then, be substance in this sense : it is the form of 
 a natural body endowed with the capacity of life. In this mean- 
 ing substance is the completed realization. Soul, therefore, will 
 be the completed realization of a body such as described. Com- 
 plete realization is employed in two senses. In the one sense it 
 is comparable with perfected knowledge; in another, it is com- 
 parable with the active process of contemplation. It is evident 
 that we mean by it here that realization which corresponds to 
 perfected knowledge. Now, both waking and sleeping are in- 
 cluded in the soul's existence: waking corresponds to active 
 contemplation; sleep to attained and inactive knowledge. In a 
 given case science is earlier in origin than observation. Soul, 
 then, is the first entelechy of a natural body endowed with the 
 capacity of life. Such a body one would describe as organic. 
 The parts of plants are also organs, although quite simple in 
 character, e.g. the leaf is the covering of the pericarp, and the 
 pericarp is covering of the fruit; the roots are analogous to 
 mouths, both being channels of nutrition. If then we were 
 obliged to give a general description applicable to all soul or 
 life, we should say that it is the first entelechy of a natural or- 
 ganic body. It is therefore unnecessary to ask whether body 
 and soul are one, as one should not ask whether the wax and the 
 figure are one, or, in general, whether the matter of a particular 
 thing and the thing composed of it are one. For although unity 
 and being are predicated in several senses, their proper sense is 
 that of perfect realization. 
 
 We have now given a general definition of the soul. We have 
 defined it as an entity which realizes an idea. It is the essential 
 notion which we ascribe to a body of a given kind. As an illus- 
 tration, suppose that an instrument, e.g. an axe, were a natural 
 body. Here the notion of axe constitutes its essential nature or 
 reality, and this would be its soul. Were this taken away it 
 would no longer be an axe, except in the sense of a homonym. 
 It is in reality, however, merely an axe, and of a body of this
 
 PSYCHOLOGY 47 
 
 sort soul is not the notional essence and the idea, but soul ap- 
 plies only to a natural body of a given kind, viz. a body whose 
 principle of movement and rest is in itself. The principle ex- 
 pressed here should be observed in its application to particular 
 parts of the body. For if the eye were an animal, vision would 
 be its soul, i.e. vision is the notional essence of the eye. The eye, 
 however, is the matter of vision, and if the vision be wanting 
 the eye is no longer an eye, save in the meaning of a homonym, 
 as a stone eye or a painted eye. What applies here to a particu- 
 lar member, must also apply to the entire living body; for as the 
 particular sensation is related to the particular organ of sense, 
 so is the whole of sensation related to the entire sensitive organ- 
 ism, in so far as it has sensation. 'Potentiality of life' does not 
 refer to a thing which has become dispossessed of soul, but to 
 that which possesses it. Seed and fruit are potentially living 
 bodies. As cutting is the realization of the axe, and vision is the 
 realization of the eye, so is the waking state the realization of 
 the living body; and as vision and capacity are related to the 
 organ, so is the soul related to the body. Body is the potential 
 substrate. But as vision and pupil on the one hand constitute 
 the eye, so soul and body in the other case constitute the living 
 animal. It is, therefore, clear that the soul is not separable from 
 the body; and the same holds good of particular parts of the 
 soul, if its nature admits of division, for in some cases the soul is 
 the realization of these very parts; not but that there are cer- 
 tain other parts where nothing forbids their possible separation, 
 because they are not realizations of any bodily nature. And 
 yet it is uncertain whether the soul as realization of the body is 
 separable from it in a sense analogous to the separability of 
 sailor and boat. Let this suffice as a definition and outline 
 sketch of the soul. 
 
 CHAPTER II. THE PRINCIPLE OF LIFE 
 
 INASMUCH as the certain and the conceptually more knowable 
 is derived from what is uncertain, but sensibly more apparent, 
 we must resume the investigation of the soul from this stand-
 
 48 ARISTOTLE 
 
 point. For it is necessary that the definition show not merely 
 what a thing is, as most definitions do, but it must also contain 
 and exhibit the cause of its being what it is. In reality, the 
 terms of definitions are ordinarily stated in the form of conclu- 
 sions. What, e.g., is the definition of squaring? The reply is that 
 squaring is the conversion of a figure of unequal sides into a 
 right-angled equilateral figure equal to the former. Such a 
 definition is the expression of a conclusion. But to define squar- 
 ing as the discovery of a mean proportional line is to define the 
 thing in terms of its cause. Resuming our inquiry, we say, 
 therefore, that the animate is distinguished from the inanimate 
 by the principle of life. But inasmuch as life is predicated in 
 several senses, e.g. in the sense of reason, sensation, local move- 
 ment and rest, and furthermore movement in the sense of 
 nutrition, decay, and growth; if any one of these is discerned 
 in a thing we say that it has life. All plants, therefore, are sup- 
 posed to have life; for evidently they have within them a po- 
 tency and principle whereby they experience growth and decay 
 in opposite processes. For their growth is not merely upwards 
 or downwards, but in both these directions alike and in every 
 point where nutrition takes place, and they continue to live as 
 long as they are capable of nutrition. Now this faculty of nutri- 
 tion is separable from the other forms of life, but the other forms 
 cannot exist in perishable creatures apart from this principle 
 of nutrition. This is made clear in the instance of plants; for 
 they have no other capacity of soul (or life) than this nutritive 
 one. Owing to this fundamental principle of nourishment, 
 therefore, life is found in all animated living things, but the 
 primary mark which distinguishes an animal from other forms 
 of life is the possession of sensation. For even those creatures 
 which are incapable of locomotion or change of place, but which 
 possess sensation, are called animals and are not merely said to 
 live. Touch is the primary form of sensation and is found in all 
 animals. But as the nutritive faculty is separable from touch 
 and sensation in general, so touch can exist apart from the other 
 forms of sensation. By the nutritive power we understand 
 that part of the soul in which plants share; and by the sensa-
 
 PSYCHOLOGY 49 
 
 tion of touch we mean that capacity which all animals possess. 
 We shall later on give the explanation of these phenomena. 
 
 For the present let it suffice that the soul is the causal princi- 
 ple of the aforesaid phenomena, and is defined in terms of them, 
 I mean, in terms of nutrition, sensation, reason, motion. To the 
 question whether each of these forms of life is a soul or a part of 
 the soul; and, if a part, whether in the sense that the part is 
 only notionally separable or really separable in space, the 
 reply is in some respects easy and in others difficult. For in the 
 case of plants, some of them appear to live when they are di- 
 vided up and the parts are separated from each other, indicat- 
 ing that there is in each of these plants in actuality an unitary 
 soul, but in potentiality several souls. And we observe the 
 same thing taking place in different varieties of soul, as e.g. in 
 the case of insects which have been dismembered. Here each 
 part is capable of sensation and locomotion, but if it is capable 
 of sensation it is also capable of imagination and impulse. For 
 where there is sensation, there is also pleasure and pain, and 
 where there is pleasure and pain there is necessarily also desire. 
 Now in regard to reason and the speculative faculty, we have 
 as yet no certain evidence, but it seems to be a generically dis- 
 tinct type of soul and it alone is capable of existing in a state of 
 separation from the body, as the eternal is separable from the 
 mortal. The remaining parts of the soul, however, are from the 
 foregoing considerations evidently not separable, as some as- 
 sert. But that they are notionally separable, is clear; for if per- 
 ceiving is distinct from opining, the faculty of sensation or per- 
 ception is distinct from that whereby we opine, and each of 
 these is in turn distinct from the faculties above mentioned. 
 Furthermore, all of these are found in some animals, while only 
 certain of them are found in others, and in still others only a 
 single one (and this is the cause of distinctions amongst ani- 
 mals). The reason for this must be investigated hereafter. A 
 parallel instance is found in regard to sensation; some animals 
 possess all the faculties of sense, others only certain of them, 
 and still others only the single most fundamental one, viz. 
 touch.
 
 50 ARISTOTLE 
 
 The principle by which we live and have sensation, then, is 
 employed in a twofold sense. Similarly, we employ the prin- 
 ciple by which we know in a twofold sense, viz. science and the 
 knowing mind (for we say we know by means of each of these), 
 and in a like manner the principle by virtue of which we are 
 healthy is in one sense health itself, and in another sense a part 
 of the body or the whole of it. In these cases knowledge and 
 health constitute the form, notion, idea, and, as it were, the 
 realization of a potential subject, the one of a knowing sub- 
 ject and the other of a healthy one, (realization is supposed to 
 attach to that which has power to effect changes and is found in 
 a passive and recipient subject). The soul is that principle by 
 which in an ultimate sense we live and feel and think; so that 
 it is a sort of idea and form, not matter and substrate. Now, 
 substance is employed, as we have said, in a threefold meaning, 
 viz. as form, as matter, and as a composite of these two. 
 Amongst these meanings of substance matter signifies potenti- 
 ality; form signifies actuality or complete realization. Inasmuch 
 as it is the composite which is the animate creature, body can- 
 not be regarded as the complete realization of the soul, but the 
 soul is the realization of a given body. The conjecture, there- 
 fore, appears well founded that the soul does not exist apart 
 from a body nor is it a particular body. The soul is not itself 
 body, but it is a certain aspect of body, and is consequently 
 found in a body, and furthermore in a body of such and such a 
 kind. It is not to be regarded as it was amongst our predeces- 
 sors who thought that it is introduced into body without prior 
 determination of the particular sort of body, although no casual 
 subject appears capable of undergoing any casual or haphazard 
 effect. 1 This same result is also reached by an analysis of the 
 notion itself; for complete realization in every instance is natu- 
 rally found in a definite potentiality and in an appropriate 
 matter. From this it is evident that the soul is a kind of realiza- 
 tion and expressed idea of a determinate potentiality. 
 
 1 Trendelenburg thinks the Pythagoreans are meant here, owing to their 
 doctrine of transmigration of souls. Cf. Deanima, 407 b 22.
 
 PSYCHOLOGY 51 
 
 CHAPTER III. THE VARIOUS MEANINGS OF 
 THE SOUL 
 
 IN some creatures, as we have said, all of the above men- 
 tioned psychic powers are found, in others certain of them, and 
 in still others only one. By powers we mean here the power of 
 nutrition, of appetite, of sensation, of movement in space, and 
 of rational thought. In plants, only the nutritive power is 
 found; in other creatures the power of sensation is added. If 
 sensation is added, impulse or appetite is also implied. For 
 appetite includes desire and impulse and wish. All animals 
 have at least one sense touch; and to whatever creature 
 sensation is given, to it are also given pleasure and pain, and 
 objects appear to be pleasant or painful. Creatures which dis- 
 tinguish these, possess also desire; for desire is an impulse 
 towards what is pleasant. Further, animals possess a sense for 
 food, and this is the sense of touch; for all animals are nourished 
 by means of the dry and moist, the warm and cold, and it is 
 touch which apprehends these. It is only incidentally that 
 animals discern food through other sensible qualities; neither 
 sound nor colour nor smell contributes at all to food. Flavour, 
 however, is one of the haptic qualities. Hunger and thirst are 
 desires; hunger is a desire of the dry and warm; thirst a desire 
 of the cool and moist, and flavour is a sort of seasoning in these 
 objects. We must explain these subjects minutely hereafter; 
 for the present let the statement suffice, that amongst animals 
 where we find touch we find appetite also. The subject of 
 imagination in animals is uncertain and must be investigated 
 later. In addition to these attributes we find amongst some 
 animals the power of local movement and in others we find the 
 power of understanding and reason, as in man and in other 
 creatures that are, if there be such, similar or superior to man. 
 It is evident that a single definition can be applied to soul in 
 the same way as a single definition can be applied to figure. As 
 in the latter case, there is no figure beyond that of the triangle 
 and its derivations, so in the former case there is no soul beyond 
 those enumerated. A common definition might also be applied
 
 52 ARISTOTLE 
 
 to figures which would fit them all and be peculiar to no par- 
 ticular figure. The same holds good in the case of the above 
 mentioned types of soul. It is, therefore, absurd, both in these 
 instances and in others, to search for a common definition which 
 shall not apply to any individual real thing nor to any peculiar 
 and irreducible species, thereby neglecting the particular mean- 
 ing in the general. The facts touching the soul are parallel to 
 this case of figure; for both in figures and in animate creatures, 
 the prior always exists potentially in the later, e.g. the triangle 
 is contained potentially in the square and the nutritive power 
 in that of sensation. We must, therefore, investigate the nature 
 of the soul in particular things, e.g. in a plant, a man, or a lower 
 animal. And we must consider the cause of their order of suc- 
 cession. The sensitive soul, for example, presupposes the nutri- 
 tive, but in the case of plants the nutritive exists apart from the 
 sensitive. Again, the sense of touch is presupposed by all the 
 other senses, but touch exists apart from them and does not 
 presuppose them. Many animals have no sense of sight, hear- 
 ing, or smell. Some that are capable of sensation have also 
 power of local movement, others have not; finally the smallest 
 number possess the power of reason and understanding. Mortal 
 creatures who possess the power of reason, possess all the other 
 psychic faculties, but those which have each of these others do 
 not all have the power of reason, and certain of them do not 
 even possess imagination, while still others live by this alone. 
 At another time we shall give an account of the speculative 
 reason. It is evident, however, that this account touching each 
 particular form of soul is also the most fitting description of the 
 soul in general. 
 
 CHAPTER IV. TEE SOUL AND FINAL CAUSE 
 
 IF one intends to make an investigation of the faculties of 
 the soul, it is necessary first to inquire into their several natures, 
 and then by the same method to inquire further into other 
 related problems. If, then, one is obliged to describe the 
 nature of each several faculty, e.g. the nature of the faculty of
 
 PSYCHOLOGY 53 
 
 reason, of sense-perception, or of nutrition, one must first be 
 able to say what thinking and sense-perception mean. For the 
 activities and processes are notionally prior to the faculties to 
 which they belong. If this is true, we must further observe the 
 objects of the activities before the activities themselves, and 
 we should for the same reason first determine our position 
 regarding these objects, e.g. regarding food, the sensible, and the 
 intelligible. First, then, we must speak of food and generation. 
 For the nutritive power is found in all living things, and is the 
 primary and most universal faculty of soul, by virtue of which 
 all creatures possess life. Its functions are to procreate, and to 
 assimilate food. In all animals that are perfect and not abnor- 
 mal, or that are not spontaneously generated, it is the most 
 natural function to beget another being similar to itself, an 
 animal to beget another animal, a plant another plant, in order 
 that they attain, as far as possible, the immortal and divine; 
 for this is what every creature aims at, and this is the final 
 cause of every creature's natural life. We understand by final 
 cause two things: the purpose aimed at, and the person who is 
 served by the purpose. Since it is impossible for an individual 
 to partake of the immortal and divine in its own continuous 
 life, because no perishable creature continues self-identical and 
 numerically one, it partakes therefore of the immortal in that 
 way in which it is able to share it, one thing in a higher degree 
 and another in a lower; it does not itself abide, but only a simi- 
 lar self abides; in its continuity it is not numerically, but only 
 specifically, one. 
 
 The soul is the cause and principle of a living body. These 
 terms are used in several senses. Corresponding to these differ- 
 ences, the soul is referred to as cause in three distinct meanings; 
 for it is cause in the sense of the source of movement, of final 
 cause, and as the real substance of animate bodies. That it is a 
 cause in the sense of real substance is evident, for real substance 
 is in every case the cause of being, and the being of animals is 
 their life, and soul is the cause and principle of life. Further- 
 more, it is the complete realization that gives us the real signifi- 
 cance of a potential being. Soul is also evidently cause in the
 
 54 ARISTOTLE 
 
 sense of final cause. For nature, like reason, acts with purpose, 
 and this purpose is its end. In animals the soul is, by virtue of 
 its nature, a principle similar to this. For the soul uses all natu- 
 ral bodies as its instruments, the bodies of animals and the 
 bodies of plants alike, which exist for the soul as their end. End 
 is used in two senses: the purpose, and the person or thing 
 which the purpose serves. Soul also means the primary source 
 of local movement. This power of local movement is not pos- 
 sessed by all living creatures. Transformation and growth are 
 also due to the soul. For sense-perception is supposed to be a 
 kind of transformation, and nothing is capable of sense-percep- 
 tion unless it has a soul. The case is similar with growth and 
 decay. For nothing grows or decays by natural processes unless 
 it admit of nutrition, and nothing is capable of nutrition unless 
 it has a soul. Empedocles ascribes downward growth to plants 
 where they are rooted, because the earth naturally tends down- 
 ward, and upward growth, because fire tends in that direction, 
 and in these respects is not right. For Empedocles does not 
 employ the terms 'up' and 'down' correctly. 'Up' and 'down' 
 are not the same for all things nor in all parts of the universe, 
 for roots are to plants what the head is to animals, if one is to 
 describe organs as identical or different in terms of their func- 
 tions. In addition, what principle is it that holds together these 
 two elements of fire and earth, tending, as they do, in opposite 
 directions? For they will scatter asunder, if there be no hinder- 
 ing principle. And if there is such a principle, it is the soul and 
 the cause of growth and nourishment. Some regard fire as the 
 real cause of nutrition and growth. For this seems to be the 
 only body or element that feeds and increases itself. One might, 
 therefore, conjecture that this is the element that causes growth 
 and nutrition in animals and plants. In a certain sense, it is 
 true, fire is a co-ordinate cause, but not the absolute cause, of 
 growth; this is rather the soul. For the growth of fire is indeter- 
 minate so long as there is material to burn; on the other hand, 
 in all bodies developed in nature there is a limit and significance 
 to size and growth. These attributes ([of limit and significance]) 
 belong to soul, not to fire, to reason rather than to matter.
 
 PSYCHOLOGY 55 
 
 Since the same power of the soul is both nutritive and gen- 
 erative, we must first investigate nutrition; for it is by this 
 function of nutrition that the faculty in question is distinguished 
 from other faculties. Nutrition is supposed to take place by the 
 law of opposites, although not every opposite is nourished by 
 every other, but such opposites only as derive both their origin 
 and their growth from each other. Many things are derived 
 from one another, but they are not all quantitative changes, as 
 e.g. healthy from sickly. Nutrition is not applied to these cases 
 in the same sense, for while water is nutriment for fire, fire does 
 not nourish water. The opposites of food and nourishment 
 appear to apply particularly to simple bodies. There is, how- 
 ever, a difficulty here. For there are some who maintain that 
 like is nourished by like, as like is also increased by like, while 
 others, as we said, affirm the converse of this, viz., that oppo- 
 sites are nourished by opposites, on the ground that like is in- 
 capable of being affected by like. Food, however, undergoes 
 transformation and is digested, and transformation is in every 
 case toward the opposite or the intermediate. Further, food is 
 affected by the body which assimilates it; the latter, however, 
 is not affected by the food, just as the builder is not affected by 
 his material, although the material undergoes change through 
 him. The builder merely passes from a state of inactivity into 
 one of activity. The question whether nourishment is to be 
 understood to apply to the final condition in which it is taken 
 up by the body, or to its original condition, creates a difficulty. 
 If both are meant, only in the one case the food is indigested 
 and in the other digested, it would be possible to speak of nour- 
 ishment conformably to both of the above theories; for in so far 
 as it is indigested, we should have opposite nourished by oppo- 
 site; in so far as it is digested, we should have like nourished by 
 like; so that in a certain sense, it is evident they are both right 
 and both wrong. Since nothing is nourished which does not 
 share life, the object of nutrition would be an animate body as 
 animate; so that food is determined by its relation to an ani- 
 mate object and is not accidental. There is a difference between 
 the nourishment and the principle of growth; in so far as the
 
 56 ARISTOTLE 
 
 animate thing is quantitative, the notion of growth applies; in 
 so far as it is a particular substance, the notion of nourishment. 
 For food preserves a being as a substantial thing, and it con- 
 tinues to exist so long as it is nourished. Nourishment is pro- 
 ductive of generation, not the generation of the nourished thing, 
 but of a being similar to it. For the former exists already as a 
 reality, and nothing generates, but merely preserves, itself. 
 So then, such a principle of the soul as we have described is a 
 power capable of preserving that in which this principle is 
 found, in so far as it is found; nourishment equips i-t for action. 
 When, therefore, it is deprived of nourishment, it can no longer 
 exist. Since there are three distinct things here: the object 
 nourished, the means of nourishment, and the power that 
 causes nutrition, we shall say that it is the elemental soul that 
 causes nutrition, the object nourished is the body which pos- 
 sesses this soul, and the means of nourishment is the food. And 
 since it is fair to give everything a name in terms of its end, and 
 since here the end of the soul is to generate a creature like to 
 itself, the elemental soul might be called generative of that 
 which is like to itself. The means of nourishment is used in two 
 senses, as is also the means of steering a ship; for one may refer 
 to the hand, or to the rudder, the one being both actively mov- 
 ing and moved; the other only passively moved. All nutriment 
 must be capable of being digested; heat is the element which 
 accomplishes digestion. Everything animate, therefore, pos- 
 sesses heat. We have explained now, in outline, what nutri- 
 ment is. The subject must be more minutely treated later on in 
 its proper place. 
 
 CHAPTER V. SENSATION AND THOUGHT 
 
 Now that we have arrived at the foregoing conclusions, 
 let us discuss in general the entire question of sense-perception. 
 It consists, as we have said, in being moved and affected; for it 
 is supposed to be a sort of internal transformation. Some main- 
 tain that like is affected by like. In what sense this is possible 
 and in what sense impossible, I have explained in a general
 
 PSYCHOLOGY 57 
 
 treatise On Activity and Passivity. A difficulty is raised by the 
 question why it is that perceptions do not arise from the senses 
 themselves, and why it is that without external stimuli they 
 produce no sensation, although fire and earth, and the other 
 elements of which we have sense-perception, are, either in their 
 essential nature or in their attributes, found in the senses. It is, 
 therefore, evident that the organ of sense-perception is not a 
 thing in actuality but only in potentiality. It is consequently 
 analogous to the combustible which does not itself ignite with- 
 out something to set it ablaze. Otherwise it would have burned 
 itself and had no need of an active fire. Inasmuch as we say 
 that perceiving is used in two meanings (e.g. we call the capacity 
 to hear and see, hearing and sight, although they may chance 
 to be dormant, and we apply the same terms where the senses 
 are actively exercised) , so sense-perception also would be used 
 in two senses, the one potential and the other actual. First of 
 all let us understand that the terms affection, motion, and 
 activity, are used in the same meaning. For motion is a sort 
 of activity, although incomplete, as we have said elsewhere. 
 Everything is affected and set in motion by an active agent and 
 by something that exists in activity. Therefore in one sense a 
 thing is affected by like, in another by unlike, as we have said; 
 for it is the unlike that is affected, but after being affected it is 
 like. 
 
 We must, further, make a distinction touching potentiality 
 and actuality, for we are now using these terms in a general 
 sense. There is a sense in which we speak of a thing as knowing, 
 as when we call man knowing, because man belongs to the class 
 of creatures that know and are endowed with knowledge. There 
 is another sense in which we speak of a man as possessing the 
 particular knowledge of grammar. In each of these cases a man 
 possesses knowledge potentially, but not in the same sense; the 
 former is knowing as belonging to a certain genus and as hav- 
 ing a native endowment; the latter is knowing in the sense of 
 being able to exercise his knowledge at will, when nothing 
 external prevents. In a still different sense there is the man who 
 is actually exercising his knowledge, and is in a condition of
 
 58 ARISTOTLE 
 
 complete realization, having in the strict sense knowledge of a 
 particular thing, as e.g. A. The first two know in a potential 
 sense; the one of them, however, knows when he is trans- 
 formed through a discipline of knowledge, and has passed re- 
 peatedly out of an opposite condition ; the other knows in the 
 sense of possessing arithmetical or grammatical science; and 
 their passing from non-actual to actual knowledge is different. 
 Again, neither is the term 'passivity' used in an absolute mean- 
 ing: in one meaning, it is destruction by an opposite principle; 
 in another meaning, it is the preservation of the potentially 
 existent by means of the actual and similar, just as potentiality 
 is related to actuality. That which possesses potential know- 
 ledge, for instance, comes to the actual use of it a transition 
 that we must either not call transformation (for the added 
 element belongs to its own nature and tends to its own realiza- 
 tion), or else we must call it a special kind of transformation. 
 It is, therefore, incorrect to speak of thinking as a transforma- 
 tion when one thinks, just as the builder is not transformed 
 when he is building a house. That which conduces to actuali- 
 zation out of a potential state in the matter of reasoning and 
 thinking is not fairly called teaching, but must be given another 
 name. Again, that which passes out of a potential state by 
 learning or by acquiring knowledge at the hands of what 
 actually knows and can teach, must either not be said to be 
 affected as a passive subject, or we must admit two meanings 
 of transformation, the one a change into a negative condition, 
 and the other into a positive condition and the thing's natural 
 state. 
 
 The first change in the sentient subject is wrought by the 
 generating parent, but after birth the creature comes into the 
 possession of sense-perception as a species of knowledge. Act- 
 ive sensation is used in a way similar to active thinking. There 
 is, however, this difference, that the objects which produce 
 sensation are external, e.g. the visible and the audible, and 
 similarly other sensible qualities. The reason for this is that 
 active sense-perception refers to particular things, while scien- 
 tific knowledge refers to the universal. These universals, how-
 
 PSYCHOLOGY 59 
 
 ever, are, in a certain sense, in the mind itself. Therefore it is 
 in one's power to think when one wills, but to experience sense- 
 perception is not thus in one's power; for a sensible object must 
 first be present. This also holds good of those sciences which 
 deal with sensible realities, and for the same reason, viz. because 
 these sensible realities belong to the world of particular and 
 external phenomena. 
 
 To go into the details of these questions would be more suit- 
 able at another time. For the present so much may be regarded 
 as fixed, viz. that the term 'potential' is not used in any abso- 
 lute sense, but in one case its meaning is similar to our saying 
 that a boy has in him the potentiality of a general-, and in an- 
 other case to our saying that a man in his prime has that poten- 
 tiality a distinction which also applies to the capacity for 
 sense-perception. Inasmuch as this distinction has no particu- 
 lar name in our language, although we have remarked that the 
 things are different and how they differ, we must simply employ 
 the terms affection and transformation as applicable here. 
 That which is capable of sense-perception is, as we have said, 
 potentially what the sensible is actually. It is, therefore, 
 affected at a moment when it is unlike, but when it has been 
 affected it becomes like and is as its object. 
 
 CHAPTER VI. SENSE QUALITIES 
 
 IN discussing any form of sense-perception we must begin 
 with the sensible object. The 'object of sense' is used in three 
 meanings, two of which touch the essential nature of sensation 
 and one its accidents. Of the two first-named, one applies spe- 
 cially to each particular sense, the other is common to them all. 
 By ' peculiar object of sense ' I mean a sense-quality which can- 
 not be apprehended by a sense different from that to which it 
 belongs, and concerning which that sense cannot be deceived, 
 e.g. colour is the peculiar object of vision, sound of hearing, 
 flavour of taste. Touch, however, discriminates several sense- 
 qualities. The other particular senses, on the contrary, dis- 
 tinguish only their peculiar objects, and the senses are not
 
 60 ARISTOTLE 
 
 deceived in the fact that a quality is colour or sound, although 
 they may be deceived as to what or where the coloured or 
 sonorous object may be. Such qualities are called the peculiar 
 objects of particular senses, whereas common objects are mo- 
 tion, rest, number, form, magnitude. Properties of the latter 
 kind are not the peculiar objects of any sense, but are common 
 to them all. Motion is apprehended by touch and by sight. 
 A thing is an object of sense accidentally, e.g. when a white 
 object proves to be the son of Diares. The latter is perceived 
 accidentally, for the person whom one perceives is an accident 
 of the white object. Therefore, the sense as such is not affected 
 by the sensible object ([as a person]). To the objects of sense, 
 strictly regarded, belong such .properties as are peculiarly and 
 properly sense-qualities, and it is with these that the essential 
 nature of each sense is naturally concerned. 
 
 BOOK III. SENSATION, IMAGINATION AND 
 THOUGHT 
 
 CHAPTER I. THE 'COMMON SENSIBLES ' 
 
 THAT there is no additional sense beyond the five we have 
 enumerated (I mean sight, hearing, smell, taste, and touch), 
 one may believe from the following considerations. Granted 
 that we really have perception of everything for which touch is 
 the appropriate sense (for all the qualities of the tangible as 
 such are apprehended by touch), it is necessary that if any 
 sensation is lacking, some organ must also be lacking in us. 
 Whatever we perceive by contact is perceived by the sense of 
 touch, with which we are endowed. On the other hand, what- 
 ever we perceive through media and not by direct contact, is 
 perceived by simple elements, such as air and water. The con- 
 ditions here are such that if several sensible objects which differ 
 from each other generically are perceived by a single medium, 
 then anyone who has a sense-organ analogous to this medium 
 must be capable of perceiving these several sense-objects. For 
 example, if the sense-organ is composed of air and the air is the
 
 PSYCHOLOGY 61 
 
 medium of both sound and colour, the organ would perceive 
 both these sense-qualities. If, on the other hand, several ele- 
 ments are mediators of the same sense-qualities, as e.g. colour is 
 mediated both by air and water (for both are diaphanous), 
 then the organ which contains one of these elements alone will 
 perceive that which is mediated by both of them. The sense- 
 organs are composed exclusively of these two simple elements, 
 air and water (for the pupil of the eye is composed of water, the 
 hearing of air, smell of one or the other of these). Fire, how- 
 ever, belongs to no organ or it is common to them all (for 
 nothing is sentient without heat). Earth belongs either to no 
 organ or it is chiefly and in a special manner combined with 
 touch. Nothing would remain, therefore, excepting air and 
 water, to constitute a sense-organ. Some animals have, in act- 
 ual fact, these organs as described. Animals which are perfect 
 and not defective have all these senses. For even the mole, as 
 one may observe, has eyes underneath its skin. Consequently, 
 unless there are bodies other than those known to us, or quali- 
 ties other than those which belong to earthly bodies, we may 
 conclude there is no sense lacking in us. 
 
 Neither is it possible that there should be any peculiar organ 
 for the perception of common properties such as we perceive 
 accidentally by means of the individual senses, e.g. common 
 properties like motion, rest, form, magnitude, number, unity. 
 For all these properties we perceive by means of motion, e.g. 
 magnitude is perceived by motion. So also is form, for form is a 
 sort of magnitude, and rest we perceive from the absence of 
 motion. We perceive numbers by the negation of continuity 
 and by the special senses, for each sensation is experienced as a 
 unit. So, then, it is clearly impossible that any particular sense 
 should apply to these common properties, such as motion. For 
 this would be like one now perceiving the sweet by means of 
 sight. This is because we happen to have senses for both qual- 
 ities ([i.e. for the sweet and for colour]) , whereby when the given 
 qualities coincide in one object, we recognize the object as 
 sweet. Otherwise we do not perceive the sweet, excepting in the 
 sense of accident, as e.g. when we recognize the son of Cleon not
 
 62 ARISTOTLE 
 
 because he is Cleon's son, but because he is a fair object, which 
 for the son of Cleon is an accident. 
 
 We have indeed a 'common sense' for the perception of 
 common qualities. I do not mean accidentally. It is therefore 
 not a particular sense, for in that case we should perceive in no 
 other way than as just now described in the illustration of 
 Cleon. A sense, however, perceives accidentally the qualities 
 that are peculiar to a different sense, not in their own nature 
 but because of the unity of these qualities, as when two sense- 
 qualities apply to the same object, e.g. in the case of bile that 
 it is both bitter and yellow. Now, it is not the function of either 
 particular sense to say that both these qualities inhere in one 
 thing and it is owing to this fact that error arises, when in the 
 case of a yellow substance one opines it to be bile. One might 
 ask why we are endowed with several senses and not with one 
 only. Is it not that facts of sequence and coincidence, such 
 as motion, magnitude, and number, might the less escape us? 
 For if we possessed sight only, and this were limited to the per- 
 ception of whiteness, then all other distinctions would the more 
 easily escape our knowledge, and because colour and magnitude 
 are always coincident, they would appear to be identical. In 
 point of fact, however, since these common qualities are found 
 in different sense-objects, it is evident that the several quali- 
 ties themselves are different. 
 
 CHAPTER II. THE 'COMMON SENSE' 
 
 BUT inasmuch as we perceive that we see and hear, we must 
 have this consciousness of vision either by the instrument of 
 sight or by some other faculty. 1 The same faculty will then 
 apply both to sight and to colour, the object of sight. In this 
 case, either we shall have two senses for the same thing, or a 
 sense will be conscious of itself. Further, if there is another 
 sense for the perception of sight, either we shall have an infinite 
 regressus, or a given sense must finally be cognizant of itself, in 
 which case one would better admit this in the instance of the 
 
 1 This function of consciousness is performed by the ' sensus communis.'
 
 PSYCHOLOGY 63 
 
 original sense itself, i.e. sight. Here, however, is a difficulty. 
 For, if sensation by means of sight is vision, and colour or that 
 which possesses colour is what we see, then the seeing faculty 
 itself must first of all have colour in order to be seen. It is plain, 
 therefore, that sensation by means of sight is not employed in 
 a single meaning. For even when we do not see, it is by means 
 of sight that we judge both of darkness and light, although 
 not in the same way. Furthermore, the seeing subject is in a 
 certain sense saturated with colour, since each sentient organ 
 receives into itself the sensible object without its matter. 
 This explains the fact that when objects of sense have been 
 removed, the sensations and images still persist in the sense- 
 organ. 
 
 The actualization of the object of sense and of the sense itself 
 is one and the same process; they are not, however, identical 
 with each other in their essential nature. I mean, for instance, 
 actual sound and actual hearing are not the same. For it is pos- 
 sible for one who has hearing not to hear, and for a sonorous 
 body not to emit sound at every instant. When, however, that 
 which has the potentiality of hearing and that which has the 
 potentiality of sounding, actually hear and actually emit sound, 
 at that moment the realized hearing and the realized sound are 
 simultaneously complete, and one would call them respectively 
 the sensation of hearing and the act of sounding. If, then, 
 movement, activity, and passivity are implied in the produced 
 object, it must be that actual sound and hearing exist in a po- 
 tential state. For creative and motive activity is given in ante- 
 cedent passivity. It is, therefore, not necessary for the moving 
 principle to be itself in actual motion. For as action and passion 
 find their expression in the object acted upon and not in the 
 producing agent, so too the actualization of the sensible object 
 and the sense-organ is expressed in the latter. The actualiza- 
 tion of a sonorous body is sound or sounding; the actualization 
 of the hearing organ is audition or hearing. For hearing is two- 
 fold and sound is twofold, and the same statement applies to 
 other senses and sense-objects. In some instances the two have 
 a distinct name, as e.g. hearing and sounding; in other instances
 
 64 ARISTOTLE 
 
 one of the two is nameless. For the actualization of sight is 
 called seeing, but the actualization of colour has no name; the 
 actualization of the organ of taste is called tasting, while the 
 actualization of flavour is nameless. Inasmuch as the actuali- 
 zation of the sense-object and the sense-organ is one and the 
 same process, although the two things differ in their essential 
 nature, it is necessary that hearing and sound, in this sense, 
 should be both either destroyed together or preserved together ; 
 and the same applies to flavour and taste, and to the other 
 sense-correlates. This necessity does not, however, apply to 
 the sense-correlates in their potential signification. On the 
 contrary, the old naturalists were wrong here, supposing, as 
 they did, that neither white nor black has existence apart from 
 sight, nor flavour apart from taste. In one way they were right 
 and in another wrong. For owing to the fact that sense and 
 sense-object have a twofold signification, namely that of poten- 
 tiality and that of actuality, their dictum was applicable to the 
 one meaning, but not to the other. They applied it, however, 
 to things absolutely which are not predicated absolutely. 
 
 If harmony is voice of a certain kind, and if voice and hearing 
 are in a sense one and the same, and in another sense not one 
 and the same, and if, further, harmony is a relation of parts, 
 hearing must likewise be a relation of parts. It is for this reason 
 ([i.e. because sensation is a kind of proportion]) that every 
 excessive stimulus, whether acute or grave, disturbs hearing. 
 In like manner the sense of taste is disturbed by excessive fla- 
 vours, the sense of sight by extremely glaring or extremely faint 
 colours, smell by excessive odours, whether cloying or acrid. 
 Consequently, qualities are agreeable when, pure and unmixed, 
 they are reduced to proportion, as e.g. the pungent, sweet, or 
 saline, or in the domain of touch, the warm and cool. It is then 
 that properties are pleasant. In general, the mixed, rather than 
 the acute or grave alone, is harmony. And sensation is propor- 
 tion. Excessive stimuli either produce pain or pervert the 
 organ. 
 
 Every sense is directed to its own peculiar sense-object; it is 
 given in the sense-organ as such, and it distinguishes the differ-
 
 PSYCHOLOGY 65 
 
 ent qualities in its appointed sense-object, as e.g. white and 
 black in the case of sight, sweet and bitter in the case of taste. 
 And the same can be said of other senses. Now inasmuch as we 
 distinguish white, sweet, and every sense-quality by its relation 
 to a particular sense, by what instrument do we perceive that 
 these qualities differ from one another? We must do so by 
 means of sensation, for they are sense-qualities. Is it not plain 
 that the flesh is not the final organ of sense? For the judging 
 subject would then necessarily distinguish an object by con- 
 tact. Neither is it possible by means of the distinct senses to 
 judge that sweet is different from white, but it is necessary that 
 both these qualities be cognized by some one faculty; other- 
 wise it would be like my perceiving one thing and you another, 
 and so proving that they are different. A single faculty must, 
 therefore, say that they are different. For the sweet is actually 
 different from the white. One and the same faculty, then, must 
 affirm this. And as this faculty affirms, so do thought and 
 perception agree. It is clear that we cannot judge of distinct 
 qualities by different senses, and we can conclude from this 
 that we cannot judge of them at distinct intervals of time. For 
 it is one and the same principle in us which says that the good is 
 different from the bad. Further, it says that they are different 
 and distinct at the moment when this affirmation is made. And 
 when is not used here in an accidental sense, by which I mean : 
 when does not apply merely to the time of the affirmation, e.g. 
 I say now that it is different, but it applies also to the thing 
 affirmed, I say that it is different now, i.e. the time applies to the 
 assertion and thing coincidently. So the two elements here are 
 inseparable, and are given in an indivisible moment of time. It 
 is impossible for the same thing or an indivisible entity to under- 
 go opposite processes simultaneously and in an indivisible mo- 
 ment of time. For if sweetness stimulates sensation or thought 
 in one way, then bitter stimulates it in an opposite way and 
 whiteness in some other way. Is, then, the judging principle l 
 something at once numerically indivisible and inseparable, 
 yet separable in the mode of its existence? There is a sense, 
 1 The judging principle is the 'common sense.'
 
 66 ARISTOTLE 
 
 then, in which as divisible it perceives the divisible, and a sense 
 in which as indivisible it perceives the indivisible. For in its 
 significant being it is divisible, but spatially and numerically it 
 is indivisible. Or is this not possible? Potentially, indeed, one 
 and the same indivisible thing may contain opposite properties, 
 but not in actuality; in its realized self it is separate, and it is 
 impossible for a thing to be at the same moment both black and 
 white. So that it is not possible for even the forms of experience 
 to undergo these opposites, if sensation and thought be such 
 forms. Rather the case here is similar to what some call a point, 
 which is divisible or indivisible, as one regards it in its single or 
 dual nature. In so far as it is indivisible, the judging principle is 
 one and coincident with perception; in so far as it is divisible, 
 it is not one, for it employs twice and simultaneously the same 
 mark. In so far as it employs a terminal mark as two, it dis- 
 tinguishes two things, and these are separable for it as a separa- 
 ble faculty. In so far as it regards the point as one, it judges 
 singly and coincidently with perception. 
 
 In this way, then, let us state our definition of the principle 
 by virtue of which we say that animals are sentient beings. 
 
 CHAPTER III. IMAGINATION 
 
 INASMUCH as the soul is defined mainly by means of two 
 attributes, namely by locomotion on the one hand and by 
 thought, judgment, and sensation on the other, it is supposed 
 that thought and reflexion are a kind of sensation (for in both 
 instances the soul discriminates and cognizes some reality), and 
 even the old writers tell us that reflexion and sensation are iden- 
 tical, as e.g. Empedocles, who said: "Wisdom groweth in man 
 in the face of a present object"; and in another verse: "Hence 
 is given unto them the power of reflecting ever and anon on 
 diverse things"; and the words of Homer have the same mean- 
 ing: " Such is the mind." For all of these ancient writers regard 
 thought as something somatic, like sensation, and believe that 
 both in sensation and thought like is apprehended by like, as 
 we said in the beginning of this treatise. They should at the
 
 PSYCHOLOGY 67 
 
 same time have spoken of error, for to animals this is more 
 natural than truth, and their souls pass most of their existence 
 in error. According to this theory, as some hold, either all 
 phenomena must be true or else error consists in the contact of 
 the unlike, for this is the opinion that is opposed to the cogni- 
 tion of like by like. Further, in this case error and knowledge of 
 opposites seem to be identical. That sensation and reflexion, 
 therefore, are not identical is evident. For all animals share in 
 the one, but few only in the other. Neither is thought, in which 
 right and wrong are determined, i.e. right in the sense of practi- 
 cal judgment, scientific knowledge, and true opinion, and wrong 
 in the sense of the opposite of these, thought in this significa- 
 tion is not identical with sensation. For sensation when applied 
 to its own peculiar objects is always true, and is inherent in all 
 animals; but it is possible for discursive thought to be false, 
 and it is found in no animal which is not also endowed with 
 reason. Imagination, too, is different from sensation and dis- 
 cursive thought. At the same time, it is true that imagination 
 is impossible without sensation, and conceptual thought, in 
 turn, is impossible without imagination. That thought and 
 conception, however, are not one and the same is evident. For 
 imagination is under our control, and can be stimulated when 
 we wish (for it is possible to call up before our eyes an imaginary 
 object, as one employs images in the art of mnemonics). Con- 
 ception, on the other hand, is not under our control. For it 
 must be either false or true. Furthermore, when we conceive 
 that something is terrible or fearful, we have at once a corre- 
 sponding feeling, and the same may be said of what inspires 
 courage. But in the case of imagination we are in the same con- 
 dition as if we were to place a terrible or a courage-inspiring 
 object before us in a picture. In conception itself there are 
 distinct forms, such as knowledge, opinion, reflexion, and their 
 opposites, concerning whose different meanings we shall speak 
 later. 
 
 Since thinking differs from sense-perception, and in one sig- 
 nification appears to be imagination and in another significa- 
 tion conception, we must proceed to the treatment of the latter,
 
 68 ARISTOTLE 
 
 after we have defined imagination. If imagination means the 
 power whereby what we call a phantasm is awakened in us, and 
 if our use of language here is not merely metaphorical, then 
 imagination is one of those faculties or mental forces in us by 
 virtue of which we judge and are capable of truth and error. 
 And these faculties include sensation, opinion, scientific know- 
 ledge, and reasoning. That imagination is not to be confounded 
 with sense-perception is plain from the following considera- 
 tions. Sensation is either a mere power or a distinct act, like 
 sight and seeing, but imagination is present when neither of 
 these conditions is realized, viz. in the phantasms of dreams. 
 Again, sensation is always present, but this is not true of imag- 
 ination. If in reality it were identical with sensation, then all 
 animals would have imagination. This does not seem to be the 
 fact, as we find in the case of the ant, the bee, and the worm. 
 Again, sensations are always true, while imaginations are for 
 the most part false. In the next place, we do not say when we 
 are accurately observing a sense-object, that we imagine it to 
 be a man. We say this rather when we do not clearly perceive 
 [and when the perception may be true or false], and as we 
 said above, we see imaginary pictures even when our eyes are 
 closed. But neither is imagination one of those faculties whose 
 deliverances are always true, as e.g. scientific knowledge and 
 reason. For imagination can also be false. It remains to be con- 
 sidered whether it is opinion, for opinion can be either true or 
 false. Opinion, however, is followed by belief (for no man can 
 have an opinion and not believe what he opines), and none of 
 the lower animals possesses belief, although imagination is found 
 in many of them. [Again, every opinion is followed by belief, as 
 belief is followed by persuasion, and persuasion by reason. Now, 
 some of the lower animals have imagination, but none of them 
 have reason.] It is plain, then, that imagination is not opinion 
 combined with sensation, nor mediated by sensation, nor a com- 
 plex of opinion and sensation, and, for the same reason, it is clear 
 that opinion has for its object nothing else than what sensation 
 has for its object. I mean e.g. that imagination is the complex 
 of an opinion of whiteness and a sensation of whiteness, and not
 
 PSYCHOLOGY 69 
 
 the complex of an opinion of goodness and a sensation of white- 
 ness. To imagine, therefore, is to opine what, strictly regarded, 
 is a sense-object. Again, there are false appearances when we 
 have correct conceptions, as e.g. in the case of the sun which 
 appears to be a foot in diameter, whereas we believe it to be 
 larger than the inhabited earth. The consequence is that we 
 must either have thrown aside our true opinion which we held, 
 without the thing having changed and without any forgetful- 
 ness or change of conviction on our part; or if one still holds it, 
 it is necessary that the same opinion be both true and false. 
 But an opinion has become false in a case where an object, with- 
 out our knowing it, has changed. Imagination, then, is not one 
 of these faculties nor a derivative of them. 
 
 Since one thing when moved can communicate motion to 
 another, and since imagination is held to be a form of motion 
 which does not come into existence without sense-perception, 
 but only in sentient creatures or in reference to objects to which 
 sensation applies, and since motion is produced by the action 
 of sense-perception, and this motion must be equal to the 
 strength of the sensation, one can affirm that the motion of 
 imagination would never be possible without sensation nor could 
 it take place in non-sentient creatures. Further, the one who 
 experiences it can act and be acted upon in many ways, and 
 one's experiences may be true or false. This truth or falsehood 
 is due to the following causes. Sense-perception is true when it 
 concerns its own peculiar objects; at any rate, there is involved 
 in this case, the least possible amount of error. In the second 
 place, sense-perception may concern the accidental, and here 
 error begins to be possible. One is not mistaken in saying that 
 a thing is white, but if one says the white object is this or that 
 particular thing, error arises. In the third place, error applies 
 to common properties and concomitants of the accidental, in 
 which peculiar properties are involved. I mean e.g. motion and 
 magnitude, which are accidental properties of sensible objects, 
 and concerning which we are especially liable to error in sense- 
 perception. The motion set up by the activity of sensation 
 will differ in terms of the three following forms of sense-percep-
 
 70 ARISTOTLE 
 
 tion. The first movement is when the sense-perception con- 
 tinues present, and this is true; the other two may be false 
 whether the object is present or withdrawn, but are especially 
 liable to error when the sense-object is removed. 
 
 If imagination contains nothing but the elements named and 
 is what we have described it to be, it would be a movement 
 stimulated by actualized sense-perception. Since sight is our 
 principal sense, imagination has derived its name from light, 
 because sight is impossible without light. Because images per- 
 sist and resemble sense-perceptions, animals regulate their 
 actions to a large degree by imagination, some of them because 
 they are incapable of reason, as the lower brutes, others because 
 reason is sometimes veiled by passion, disease, or sleep, as is the 
 case amongst men. Concerning imagination, what its nature 
 is and what end it subserves, let the foregoing suffice. 
 
 CHAPTER IV. THE THEORY OF REASON 
 
 REGARDING that part of the soul by virtue of which one 
 knows and reflects, whether it be a distinct part or whether it 
 be distinct only notionally and not really, we have now to con- 
 sider what its differential mark is, and by what process thinking 
 is exercised. If thinking is like sense-perception, it would be 
 either a kind of impression made by the object of cognition or 
 some analogous process. It must, then, be impassive and yet 
 receptive of the form, and in its nature potentially like to the 
 object of thought without being this object; and as the sense- 
 organ is related to the object of sense, in a similar way thought 
 must be related to the object of thought. Reason must, there- 
 fore, be unmixed, as Anaxagoras says, since it thinks every- 
 thing, in order that it may rule, i.e. in order that it may know. 
 It is the nature of thought to preclude and restrain the element 
 that is foreign and adjacently seen. Its nature is, therefore, 
 exclusively potentiality. What we call reason in the soul (by 
 reason I mean the instrument by which the soul thinks and 
 forms conceptions) is, prior to the exercise of thought, no reality 
 at all. It is, therefore, wrong to suppose that reason itself is
 
 PSYCHOLOGY 71 
 
 mixed with the body. For in that case it would have certain 
 qualitative distinctions such as warm or cold, or it would be a 
 sort of instrument, like a sense-organ. But in point of fact it is 
 nothing of the kind. Certain writers l have happily called the 
 soul the place of ideas, only this description does not apply to 
 the soul as a whole, but merely to the power of thought, and 
 it applies to ideas only in the sense of potentiality, and not 
 of actuality. It is evident from the sense-organ and from the 
 nature of sensation, that the term impassivity is employed in 
 a different meaning in sensation and in thinking. For sense- 
 perception cannot take place when the sense-stimulus is exces- 
 sive, as one does not hear sound in the midst of loud noises, 
 neither can one see nor smell in the midst of excessively bright 
 colours and strong odours. On -the other hand, when the mind 
 thinks a very profound thought, it thinks not in a lesser but in a 
 deeper degree minor details. For the power of sensation is not 
 independent of the body, while the mind is separable. When 
 reason becomes its several objects in the sense in which an 
 actually learned man is said to be learned (and this takes place 
 when he can exercise knowledge through his own agency), even 
 then reason is in a certain sense potential, although this poten- 
 tiality differs from that which preceded learning and discovery. 
 In the latter case, potentiality signifies the capacity of thinking 
 itself. 
 
 There is a difference between concrete magnitude and the 
 ultimate nature of magnitude, between water and the ultimate 
 nature of water (the same distinction can be applied to other 
 instances, though not to all, for in some cases they are identi- 
 cal). Concrete flesh and the ultimate nature of flesh one judges 
 either by a different and distinct faculty or by the same faculty 
 under differing conditions. Flesh is not separate from matter, 
 but like a snub-nose, it is a particular thing in a given some- 
 thing. By means of a sense-organ one discriminates heat and 
 cold and those qualities of which flesh is a sort of register. On 
 the other hand, reason judges of the essential nature of flesh 
 either by a different and distinct faculty, or in the way in which 
 
 1 Plato and the Academy.
 
 72 ARISTOTLE 
 
 a bent line is related to itself when straightened. We refer the 
 straight line as we do the snub-nose to abstract entities, for they 
 are both associated with the continuous. But the essential no- 
 tion of a thing, if straightness and the straight line are different 
 (and they are two things), is apprehended by a different power. 
 The mind, then, judges in the two cases by means of a differ- 
 ent power or by means of a power differently conditioned. In a 
 word, therefore, as there are things abstracted from matter, so 
 there are things that concern the reason. If the mind is simple 
 and impassive, and has nothing in common with anything else, 
 as Anaxagoras l says, and if thinking means to be somehow im- 
 pressed, one might ask, How will thought be possible? For it is 
 only in so far as there is something common to two things that 
 the one appears to act and the other to be acted upon. A further 
 question might be raised, viz. whether the mind itself is the 
 object of thought. If it is, mind will then either be found in 
 other things, unless it is the object of thought in some way 
 different from other objects, and unless the object of thought is 
 a specific and single thing; else it will have a mixed composition 
 which makes it like other things, the object of thought. Accord- 
 ing to our former definition, 'to be affected in reference to a 
 common element,' means that the mind is potentially the object 
 of thought, though perhaps not actually so until thought takes 
 place. It must be that the case here is similar to that of the tab- 
 let on which nothing has been actually written. This is what 
 takes place in the case of mind, and it is the object of thought 
 as other things are. Where entities are without matter, the 
 subject and object of thought are identical. Speculative thought 
 and the thing speculatively known are one and the same. The 
 reason why thought is not continuous must be investigated. 
 On the other hand, when entities are material they are severally 
 the object of thought only potentially; mind is not an element 
 in them (for reason is the potentiality of such objects in abstrac- 
 tion from their matter), whereas it is in the reason itself that 
 the object of thought will be found. 
 
 1 In his theory of sensation Anaxagoras says we do not apprehend like by 
 like (Empedocles), but unlike by unlike, e.g. heat by cold.
 
 PSYCHOLOGY 73 
 
 CHAPTER V. ACTIVE AND PASSIVE REASON 
 
 IN the whole of nature there is on the one hand a material 
 factor for every kind of thing (and this is what all things are in 
 their potentiality), and another factor which is causative and 
 productive of things, by virtue of its making all objects, as art 
 stands related to the matter it employs. These distinctions 
 must also hold good when applied to the soul. Reason is of such 
 character that on the one hand it becomes all things, and on the 
 other creates all things, in this respect resembling a property 
 like light. For light in a certain sense converts potential into 
 actual colours, and reason, in the present meaning, is separate, 
 impassive, and unmixed, being in its essential nature an ener- 
 gizing force. Now, action is always higher than passion and 
 causal force higher than matter. Actual knowledge is identical 
 with its object. Potential knowledge, on the other hand, pre- 
 exists in the individual; regarded absolutely it does not so pre- 
 exist. For mind does not at one moment think and at another 
 not. In its separated state alone reason is what it is, immortal 
 and eternal. We have no memory of it, because this part of 
 reason is impassive. The passive reason, on the other hand, is 
 perishable, and without it there can be no thought. 
 
 CHAPTER VI. THOUGHT AND TRUTH 
 
 WHEN thought is applied to indivisible terms, error does not 
 arise. Where error and truth are both found is just in the com- 
 bination of thoughts into a sort of unity. Empedocles e.g. says: 
 "Wherefore the heads of many creatures sprang into life with- 
 out necks," and later on by the attraction of Friendship they 
 were joined together. So, too, these disjoined ideas are combined 
 together by the reason, as e.g. the ideas of the incommensur- 
 able and the diagonal. If the ideas refer to the past or to the 
 future, the element of time is added in the mind and combined 
 with the ideas. Error is always due to the combination. For 
 even in the case where one might think the white not to be white, 
 one has made the combination of the 'not-white.' It is further
 
 74 ARISTOTLE 
 
 possible to apply disjunction to everything. It is not only pos- 
 sible for the statement 'Cleon is fair' to be true or false, but 
 this may be applied to the past or to the future. The unifying 
 principle is in every case the reason. Since the simple or indi- 
 visible may be looked at from two standpoints, viz. either as 
 potentiality or as actuality, there is nothing to prevent the 
 mind from thinking the indivisible when it thinks of extension 
 (which in its actual state is indivisible), and when it thinks it in 
 an indivisible moment of time. For divisibility and indivisi- 
 bility apply to time just as they do to length. It is, therefore, 
 impossible to say what the mind thinks in each half of a time- 
 division. For the half does not exist, except in potentiality, if 
 the division has not been made. But in the act of thinking each 
 half separately, the mind divides the time also, and then the 
 time corresponds in its division to the two lengths. If, however, 
 the mind thinks the object as a whole composed of two halves, 
 it does this also with regard to time in its relation to the two 
 halves. 
 
 That which is not quantitatively but only notionally indi- 
 visible, the mind thinks in an indivisible time and by an in- 
 divisible power of the soul. It does this, however, accidentally 
 and not in so far as the factors of thought and time are divisible, 
 but in so far as they are indivisible. And there is also in these 
 cases an objective factor which is indivisible, although perhaps 
 not a separate entity, that gives a unity to time and extension. 
 And this is likewise true of everything that is continuous, 
 whether in time or space. The point and everything obtained 
 by division, and whatever (like a point) is no longer divisible, 
 are explicable in terms of privation. Similar reasoning may be 
 applied to other cases, as e.g. the way in which we know evil or 
 black. For we know them somehow or other by means of their 
 contraries. But the knowing mind must be these things poten- 
 tially, and they must be reduced to unity in the mind itself. If, 
 however, in the case of any causal principle there is no. opposite, 
 then it knows itself, and is in actuality and is separate. A pre- 
 dication, as e.g. an affirmation, asserts something of something 
 else, and is in every instance either true or false. This does not
 
 PSYCHOLOGY 75 
 
 apply to the mind always, but when the mind asserts what a 
 thing is in its essential nature and not what attaches to some- 
 thing as a predicate, then it is true. And just as sight is true 
 when it concerns its own proper object, and on the other hand 
 the opinion that a visible white object is or is not a man may 
 not always be true, so it is with all immaterial entities. 
 
 CHAPTER VIL THOUGHT AND ITS OBJECT 
 
 ACTUAL knowledge is identical with its object. Potential 
 knowledge is earlier in time in the individual, but taken abso- 
 lutely it is not earlier in time. For all becoming proceeds from 
 actual being. The sensible object appears to convert the poten- 
 tially sensitive organ into an actually sensitive organ. For the 
 sense-organ itself is not affected, and undergoes no change. 
 That is the reason why we have here to do with a form of mo- 
 tion different from motion in the ordinary sense. Motion was 
 defined as a realization of the incomplete, but motion, abso- 
 lutely regarded, is a different kind of activity, viz. the activity 
 of the perfected thing. Mere sense-perception, then, is like a 
 simple expression or a simple thought; when, however, the 
 sensation is pleasant or painful, and thus corresponds to affir- 
 mation or negation, the thing is pursued or avoided. To feel 
 pleasure or pain signifies to experience an activity in a mean 
 function of the sense-organ relative to good or bad as such. 
 Avoidance and pursuit in their actual natures are identical, 
 and the appetitive power whereby we desire or pursue a thing is 
 not different from the power whereby we avoid a thing. They 
 do not differ from each other or from the sensitive faculty. 
 Only the expression of their being is different. Images are em- 
 ployed by the conceptual reason as sense-presentations are by 
 the sentient faculty. When the mind makes an affirmation or 
 negation touching the good or bad, it avoids the one and pur- 
 sues the other. The soul, therefore, never thinks without the 
 use of images. As the air produces such or such an effect on the 
 pupil of the eye, and the pupil in turn produces another effect 
 (the same illustration may be applied to hearing), and yet the
 
 76 ARISTOTLE 
 
 ultimate interpreter or medium of sensation is a single power 
 whose being is expressed in several ways, ([so it is with images 
 in reference to thought.]) As to the faculty by which we dis- 
 criminate sweet and warm, although the problem has been 
 mentioned above, it must be again discussed as follows. There 
 is some unitary principle, and this unitary principle has the 
 character of an ultimate term. Its deliverances are reduced 
 to unity by means of comparison and numerical statement, and 
 related to each other as the outward things are related to each 
 other. The question as to how the mind judges like qualities, 
 does not differ from the question as to how it judges opposite 
 qualities such as white and black. Let A, the objectively white, 
 be related to B, the objectively black, as the idea C is related to 
 the idea D, or it may be stated conversely. Now, if the ideas 
 CD attach to a certain thing, they will be related to each other 
 ([in the concept]) just as AB are related to each other, they 
 will form one and the same thing, though not identical in mode 
 of being; and the former combination (CD) is analogous to the 
 latter (AB). The same reasoning holds in case one were to 
 apply A to a sweet object, and B to a white object. 
 
 The reasoning mind thinks its ideas in the form of images; 
 and as the mind determines the objects it should pursue or 
 avoid in terms of these images, even in the absence of sensation, 
 so it is stimulated to action when occupied with them. For 
 example, when one sees that a beacon is lighted, and observes 
 by means of the 'common sense' that it is in motion, one com- 
 prehends that an enemy is near. Sometimes by means of the 
 images or ideas in the soul the mind reasons as a seeing person, 
 and takes thought for the future in terms of things before one's 
 eyes. When the mind there in its world of images says that a 
 thing is pleasant or painful, here in the world of things it pur- 
 sues or avoids, in a word, it acts. Apart from action the true 
 and false belong to the same category as the good and bad. 
 They differ, however, in the absolute character of the one and 
 the relative character of the other. 
 
 The mind thinks abstractions, as e.g. when it thinks the snub- 
 nosed, which in one sense is a snub-nose, and in another sense,
 
 PSYCHOLOGY 77 
 
 if one thinks it actually, one would think it as a curvature with- 
 out the flesh in which the curvature is found. So too with math : 
 ematical figures, though in actuality not separate from bodies, 
 the mind thinks them as separated, when it thinks them. In a 
 word the mind is the thing when actually thinking it. Whether 
 or not it is possible to think any abstraction when the mind it- 
 self is not separate from magnitude, must be investigated later. 
 
 CHAPTER VIII. IDEAS AND IMAGES 
 
 LOOKING at the main features of what has been said of the 
 soul, let us reiterate the statement that it is in a sense all reality. 
 For everything, whether sensible or intelligible, is psychical ; 
 intelligible objects are in a sense knowledge, and sensible reali- 
 ties are sensations. How this is possible remains to be investi- 
 gated. Conceptual knowledge and sense-perception are each 
 divided into two minds, corresponding to their objects; potential 
 knowledge corresponding to potential objects, and actual to 
 actual. The sensitive and conceptual powers of the soul are, 
 potentially regarded, the objective things, viz. the intelligible 
 and the sensible. The soul, then, must be either the things 
 themselves or their form. It cannot, of course, be the things 
 themselves. For a stone is not in the soul, but the form or idea 
 of the stone. Consequently, the soul is to be thought of as a 
 hand; for a hand is the instrument of all instruments, and the 
 reason is the form of all forms and sensation in the form of all 
 sensible realities. Since, however, there is no object, as is sup- 
 posed, apart from sensible magnitudes, it follows that intel- 
 ligible objects, I mean abstractions, as we call them, on the 
 one hand, and the qualities and conditions of the sensibles, 
 on the other, must be sought in the sense-forms. For this 
 reason, also, it would be impossible for one to learn anything 
 or understand anything without sense-perception, and when 
 one contemplates a thing, one is forced to contemplate it in 
 conjunction with an internal image. These images are like 
 sense-presentations, with the exception that they are without 
 matter. Imagination is different from affirmation and nega-
 
 78 ARISTOTLE 
 
 tion; for the true and the false are the combination of ideas into 
 a judgment. In what way are the primary ideas to be distin- 
 guished from imagination? Or is it true that these ideas are not 
 themselves images, yet they cannot be produced independently 
 of images? 
 
 CHAPTER IX. REASON AND DESIRE 
 
 SINCE the soul of living beings is defined in terms of two 
 powers, viz. the power of judgment (which is the function of 
 thought) and the power of sensation on the one hand, and the 
 power of locomotion on the other, let the above suffice for our 
 treatment of sensation and thought, and let us now consider 
 the moving principle and ask what part of the soul it may be. 
 The further question arises whether it is an individual part of 
 the soul and separate, either concretely or notionally, or whether 
 it is the entire soul. If it is only a part, we must ask whether 
 it is a peculiar part and distinct from -those usually described 
 and already mentioned here, or whether it is one of these. There 
 is a difficulty at the start concerning the sense in which we are 
 to employ the term 'parts' of the soul, and concerning their 
 number. For in a certain way they seem to be innumerable, and 
 not merely confined to those which certain writers distinguish, 
 viz. reason, will, and desire, 1 and others classify as rational and 
 irrational elements. For according to the differences by which 
 they distinguish these parts, there seem to be other parts that 
 are even more distinct from each other than these, concerning 
 which we have just now spoken, viz. the nutritive part, which 
 is found even in plants as well as in all animals, and the sensi- 
 tive part, which one could not easily classify either as irrational 
 or as rational. Again, the power of imagination, which is differ- 
 ent in its mode of being from the others, appears to be a distinct 
 part, but in what particular it is identical with or different from 
 the others, is very difficult to say, if one is to regard the parts 
 of the soul as existing independently of one another. In addi- 
 tion to these, there is the desiderative part, which both notion- 
 1 Plato, Republic 441 A (X^um^?, Ovuoetdts, firi6viJ.rfTi.K6v').
 
 PSYCHOLOGY 79 
 
 ally and functionally might be supposed to differ from all the 
 other parts. And yet it would be absurd to sever this from the 
 others. For it is in the thinking element that volition arises, 
 and in the irrational element we have desire and passion. But 
 if the soul has three distinct parts, then the desiderative ele- 
 ment must be in all of them. Moreover, the question again 
 comes up which we raised just now, viz. what is the principle in 
 animals that produces locomotion? One might suppose that it 
 is the generative and nutritive powers, found in all living 
 things, that produce the motion involved in growth and decay 
 common to them all. The subjects of inspiration and expira- 
 tion, sleeping and waking, must be investigated later, for all of 
 them present great difficulties. But regarding locomotion, we 
 must inquire what it is that gives animals the power of pro- 
 gressive movement. It is evidently not the nutritive power, for 
 progressive movement is always towards some end and accom- 
 panied either by some image or desire. For where there is no 
 desire or revulsion, there is no motion, excepting where exter- 
 nal force is used. Further, if motion were due to the nutritive 
 power, plants would be capable of locomotion and would have 
 some organic member adapted to this motion. So, too, it 
 cannot be the sensitive power that is the source of motion ; for 
 there are many animals which have sensation and yet, through- 
 out their existence, are stationary and motionless. If, then, 
 nature creates nothing in vain, neither does she omit anything 
 that is necessary, save in cases of deformed or imperfect beings. 
 And such animals as we have in mind are normal and not de- 
 formed. A test of perfection is the capacity to reproduce, to 
 reach the prime of growth, and then decline. Consequently, 
 such animals should also have organs of movement. 
 
 But neither is the thinking power nor what we call reason the 
 cause of animal motion. For the contemplative power does not 
 think upon what is to be carried into execution, neither has it 
 anything to say touching what is to be avoided or pursued, 
 whereas motion always belongs to that which pursues or avoids 
 an object. On the contrary, when one contemplates anything, 
 the mind does not bid one pursue or avoid; e.g. the fearful or
 
 80 ARISTOTLE 
 
 pleasant is often the subject of thought, but the feeling of fear 
 is not suggested; the heart, however, is agitated, or if the feeling 
 is pleasure, some other organ is stirred. More than this, even 
 when the reason commands and intelligence tells us to avoid or 
 to pursue a thing, motion does not follow, but one acts accord- 
 ing to one's desire, like an intemperate man. We observe, in 
 general, that the man versed in medicine does not heal, because 
 it is something other than science that has the power of acting 
 according to the principles of science. Neither, again, is desire 
 the dominating principle in this motion; for continent men, 
 though filled with desire and appetite, do not do the things for 
 which they lust; on the contrary, they follow reason. 
 
 CHAPTER X. PSYCHOLOGY AND CONDUCT 
 
 THERE are two powers in the soul which appear to be moving 
 forces desire and reason, if one classifies imagination as a 
 kind of reason. For many creatures follow their imaginations 
 contrary to rational knowledge, and in animals other than 
 man it is not thought nor rational procedure that determines 
 action, but imagination. Consequently, both of these, rea- 
 son and desire, can produce locomotion I mean here the 
 reason that considers ends and is concerned with conduct. It 
 differs from the theoretical reason in having a moral end. 
 Every desire aims at something. It is the final end that is the 
 initial cause in conduct. So that it is reasonable to regard 
 these two principles, viz. desire and practical reason, as motor 
 forces. For the object of desire stimulates us, and through it 
 reason stimulates us, because the object of desire is the main 
 thing in the practical reason. Imagination, too, when it stimu- 
 lates us to action, does not do so independently of desire. The 
 one single moving force is the object of desire. For even if 
 there were two moving powers, reason and desire, still they 
 would produce movement in accordance with some common 
 idea. As a matter of fact, however, reason does not appear to 
 produce movement independently of desire. For volition is a 
 form of desire, and when one is prompted to action in accord-
 
 PSYCHOLOGY Si 
 
 ance with reason, the action follows also in accordance with 
 volition. But desire prompts actions in violation of reason. For 
 appetite is a sort of desire. Reason, then, is in every case right, 
 but desire and imagination may be right or wrong. It is, there- 
 fore, always the object of desire that excites action, and this is 
 either the good or the apparent good yet not every good, but 
 only the good in conduct, and this practical good admits of 
 variation. 
 
 Evidently the psychical power which excites to action has the 
 nature of desire, as we call it. In analysing the elements of the 
 soul, if one analyses and distinguishes them in terms of powers, 
 they become very numerous, as e.g. the nutritive, sensitive, 
 rational, deliberative, and desiderative. For these differ from 
 each other more than do the desiderative and spirited elements. 
 Although desires arise which are opposed to each other, as is the 
 case when reason and appetite are opposed, it happens only in 
 creatures endowed with a sense of time. (For reason, on account 
 of the future, bids us resist, while desire regards the present; the 
 momentarily pleasant appears to it as the absolutely pleasant 
 and the absolutely good, because it does not see the future.) 
 The moving principle, which is the desiderative faculty as such, 
 is specifically one, though numerically several motive forces 
 may be included in it. The main element here is the object of 
 desire (for this by being the object of thought or imagination 
 excites movement, while it is itself unmoved). There are, then, 
 three terms to consider here: first the motor power, secondly 
 the instrument of motion, and thirdly the object set in motion. 
 The motor power is twofold: on the one hand, it is an unmoved 
 element, and on the other, a moving and moved element. The 
 unmoved element is the good to be done ; the moving and moved 
 element is the desiderative faculty (for the desiderative faculty 
 in so far as it desires is moved, and desire in process of realiza- 
 tion is a form of motion) ; the object which is set in motion is 
 the animal. The instrument by which desire effects motion, 
 is of course the body, and consequently it must be investigated 
 where we have to do with functions which are common to the 
 body and the soul. One may, however, say summarily here that
 
 82 ARISTOTLE 
 
 motion is organic in those cases where beginning and end are 
 one, as e.g. in a joint. For here the convex and concave are 
 beginning and end. Therefore the one is at rest and the other 
 in motion, and while they are notionally distinct, they are con- 
 cretely inseparable. Everything is set in motion by push or 
 pull, and there must be, consequently, a fixed point, as the cen- 
 tre in a circle, and this is the initial point of motion. In a word, 
 then, as we said before, an animal in so far as it is capable of 
 desire is capable of self-movement. Desire, however, is not 
 found apart from imagination, and all imagination is either 
 rational or sensitive in origin, and the lower animals share in it. 
 
 CHAPTER XL THE MOVING PRINCIPLE 
 
 WE must inquire also into the nature of the moving princi- 
 ple in those imperfect animals which possess only the sense of 
 touch. Is it possible for them to have imagination or desire? 
 They appear to feel pleasure and pain, and if these are felt they 
 must necessarily have desire also. But how could they have 
 imagination? Or are we to say that just as their movements are 
 indefinite, so too this power is possessed by them, only it is 
 infinitely developed. Imagination derived from sensation is, as 
 we said before, found in the lower animals, but deliberative 
 imagination is found only in those animals which are endowed 
 with reason. For whether one shall do this or that is, of course, 
 a matter of deliberation, and there must be some single instru- 
 ment of measurement at hand (for it is the greater good that is 
 to be pursued) , and so the mind is able to make a single repre- 
 sentation out of several images. The ground for supposing that 
 animals do not have opinion is that they do not have the faculty 
 for drawing rational conclusions, and opinion involves this. 
 Consequently, their desire lacks the deliberative quality. 
 Sometimes the desire overpowers the deliberative element in 
 man and excites to action. At other times the will overpowers 
 the desire, and again, like a ball tossed to and fro, one desire 
 overpowers another, as in the case of intemperance. In the 
 workings of nature the higher element always has the .greater
 
 PSYCHOLOGY 83 
 
 authority and is the moving power. There are, then, three forms 
 of movement. The faculty of conceptual thought is not moved, 
 but remains at rest. Since we have two principles in conduct, 
 on the one hand the general conception and notion, and on the 
 other hand the particular notion (of which the one says a man 
 of such and such a kind shall act in such a way, and the other 
 that this particular man and I am that particular man 
 shall act in a given way), it is the latter notion that incites to 
 action, but the general one does not. Or both of them combined 
 may lead to action, although the general notion is quiescent, 
 and the particular one active.
 
 ZENO 
 
 (356-264) 
 
 FROM DIOGENES LAERTIUS' LIVES 
 
 AND OPINIONS OF EMINENT 
 
 PHILOSOPHERS 
 
 Translated from the Greek* by 
 CHARLES D. YONGE 
 
 BOOK VII. THE PSYCHOLOGY OF THE STOICS 
 
 THE Stoics have chosen to treat, in the first place, of percep- 
 tion and sensation, because the criterion by which the truth of 
 facts is ascertained is a kind of perception, and because the 
 judgment which expresses the belief, and the comprehension, 
 and the understanding of a thing, a judgment which precedes 
 all others, cannot exist without perception. For perception 
 leads the way; and then thought, finding vent in expressions, 
 explains in words the feelings which it derives from perception. 
 But there is a difference between (^avraa-ia and ^dv-raafia. For 
 <f>dvTa<T/jba is a conception of the intellect, such as takes place in 
 sleep; but ^avraa-ia is an impression, rurr&Hm, produced on 
 the mind, that is to say, an alteration, aXXoiWt?, as Chry- 
 sippus states in the twelfth book of his treatise on the Soul. 
 For we must not take this impression to resemble that made by 
 a seal, since it is impossible to conceive that there should be 
 many impressions made at the same time on the same thing. 
 But (fravTaa-ia is understood to be that which is impressed, 
 and formed, and imprinted by a real object, according to a real 
 object, in such a way as it could not be by any other than a real 
 object; and, according to their ideas of the fyavTaa-iai, some are 
 
 * From Awy^coi/s Aatprlov irtpl fiiov Soyndruv KO.I diro<f>0eyndT<i)i> rdv iv 0tX- 
 offoQlq. evdoKi/j.i}ffdi>Twv pifiXla. Slua. Reprinted from Diogenes Laertius's Lives and 
 Opinions of Eminent Philosophers, translated by C. D. Yonge. Lond., 1853.
 
 DIOGENES LAERTIUS' LIVES 85 
 
 sensible, and some are not. Those they call sensible, which are 
 derived by us from some one or more senses ; and those they 
 call not sensible, which emanate directly from the thought, as 
 for instance, those which relate to incorporeal objects, or any 
 others which are embraced by reason. Again, those which are 
 sensible, are produced by a real object, which imposes itself on 
 the intelligence, and compels its acquiescence; and there are 
 also some others, which are simply apparent, mere shadows, 
 which resemble those which are produced by real objects. 
 
 Again, these favrda-icu are divided into rational and irra- 
 tional; those which are rational belong to animals capable of 
 reason ; those which are irrational to animals destitute of reason. 
 Those which are rational are thoughts ; those which are irrational 
 have no name; but are again subdivided into artificial and not 
 artificial. At all events, an image is contemplated in a different 
 light by a man skilful in art, from that in which it is viewed by a 
 man ignorant of art. 
 
 By sensation, the Stoics understand a species of breath which 
 proceeds from the dominant portion of the soul to the senses, 
 whether it be a sensible perception, or an organic disposition, 
 which, according to the notions of some of them, is crippled 
 and vicious. They also call sensation the energy, or active exer- 
 cise, of the sense. According to them, it is to sensation that we 
 owe our comprehension of white and black, and rough and 
 smooth: from reason, that we derive the notions which result 
 from a demonstration, those for instance which have for their 
 object the existence of Gods, and of Divine Providence. For 
 all our thoughts are formed either by indirect perception, or by 
 similarity, or analogy, or transposition, or combination, or oppo- 
 sition. By a direct perception, we perceive those things which 
 are the objects of sense; by similarity, those which start from 
 some point present to our senses ; as, for instance, we form an 
 idea of Socrates from his likeness. We draw our conclusions by 
 analogy, adopting either an increased idea of the thing, as of 
 Tityus, or the Cyclops; or a diminished idea, as of a pigmy. So, 
 too, the idea of the centre of the world was one derived by 
 analogy from what we perceived to be the case of the smaller
 
 86 ZENO 
 
 spheres. We use transposition when we fancy eyes in a man's 
 breast; combination, when we take in the idea of a Centaur; 
 opposition, when we turn our thoughts to death. Some ideas 
 we also derive from comparison, for instance, from a compari- 
 son of words and places. 
 
 There is also nature; as by nature we comprehend what is 
 just and good. And privation, when for instance, we form a 
 notion of a man without hands. Such are the doctrines of the 
 Stoics, on the subject of phantasia, and sensation, and thought. 
 
 XXXVII. They say that the proper criterion of truth is the 
 comprehension, {fravracria ; that is to say, one which is derived 
 from a real object, as Chrysippus asserts in the twelfth book of 
 his Physics; and he is followed by Antipater and Apollodorus. 
 For Boethius leaves a great many criteria, such as intellect, 
 sensation, appetite, and knowledge; but Chrysippus dissents 
 from his view, and in the first book of his treatise on Reason, 
 says, that sensation and preconception are the only criteria. 
 And preconception is, according to him, a comprehensive 
 physical notion of general principles. But others of the earlier 
 Stoics admit right reason as one criterion of the truth ; for in- 
 stance, this is the opinion of Posidonius, and is advanced by 
 him in his essay on Criteria. 
 
 LXIIL The Stoics also say that the mind is divisible into 
 eight parts; for that the five organs of sensation, and the vocal 
 power, and the intellectual power, which is the mind itself, and 
 the generative power, are all parts of the mind. But by error, 
 there is produced a perversion which operates on the intellect, 
 from which many perturbations arise, and many causes of in- 
 constancy. And all perturbation is itself, according to Zeno, a 
 movement of the mind, or superfluous inclination, which is 
 irrational, and contrary to nature. Moreover, of the superior 
 class of perturbations, as Hecaton says, in the second book of 
 his treatise on the Passions, and as Zeno also says in his work 
 on the Passions, there are four kinds, grief, fear, desire, and 
 pleasure. And they consider that these perturbations are judg- 
 ments, as Chrysippus contends in his work on the Passions; for 
 covetousness is an opinion that money is a beautiful object, and
 
 DIOGENES LAERTIUS' LIVES 87 
 
 in like manner drunkenness and intemperance, and other things 
 of the sort, are judgments. And grief they define to be an irra- 
 tional contraction of the mind, and it is divided into the follow- 
 ing species, pity, envy, emulation, jealousy, pain, perturbation, 
 sorrow, anguish, confusion. Pity is a grief over some one, on the 
 ground of his being in undeserved distress. Envy is a grief, at 
 the good fortune of another. Emulation is a grief at that be- 
 longing to some one else, which one desires one's self. Jealousy 
 is a grief at another also having what one has one's self. Pain is 
 a grief which weighs one down. Perturbation is grief which 
 narrows one, and causes one to feel in a strait. Sorrow is a 
 grief arising from deliberate thought, which endures for some 
 time, and gradually increases. Anguish is a grief with acute 
 pain. Confusion is an irrational grief, which frets one, and pre- 
 vents one from clearly discerning present circumstances. But 
 fear is the expectation of evil ; and the following feelings are all 
 classed under the head of fear : apprehension, hesitation, shame, 
 perplexity, trepidation, and anxiety. Apprehension is a fear 
 which produces alarm. Shame is a fear of discredit. Hesitation 
 is a fear of coming activity. Perplexity is a fear, from the im- 
 agination of some unusual thing. Trepidation is a fear accom- 
 panied with an oppression of the voice. Anxiety is a fear of 
 some uncertain event. 
 
 Again, desire is an irrational appetite; to which head, the 
 following feelings are referrible : want, hatred, contentiousness, 
 anger, love, enmity, rage. Want is a desire arising from our 
 not having something or other, and is, as it were, separated 
 from the thing, but is still stretching, and attracted towards it 
 in vain. And hatred is a desire that it should be ill with some 
 one, accompanied with a certain continual increase and exten- 
 sion. Contentiousness is a certain desire accompanied with 
 deliberate choice. Anger is a desire of revenge, on a person who 
 appears to have injured one in an unbecoming way. Love is a 
 desire not conversant about a virtuous object, for it is an at- 
 tempt to conciliate affection, because of some beauty which is 
 seen. Enmity is a certain anger of long duration, and full of 
 hatred, and it is a watchful passion, as is shown in the following 
 lines:
 
 88 ZENO 
 
 For though we deem the short-liv'd fury past, 
 'T is sure the mighty will revenge at last.* 
 
 But rage is anger at its commencement. 
 
 Again, pleasure is an irrational elation of the mind over 
 something which appears to be desirable; and its different 
 species are enjoyment, rejoicing at evil, delight, and extrava- 
 gant joy. Enjoyment, now, is a pleasure which charms the 
 mind through the ears. Rejoicing at evil (eVi^at/ae^a/aa), is a 
 pleasure which arises at the misfortunes of others. Delight 
 (rejoi/ri?) that is to say turning (r/oo/ri?), is a certain turning of 
 the soul (TrporpoTTij T ^v%^<?) , to softness. Extravagant joy 
 is the dissolution of virtue. And as there are said to be some 
 sicknesses (ap/Wr^/mra) in the body, as, for instance, gout and 
 arthritic disorders; so too are those diseases of the soul, such as 
 a fondness for glory, or for pleasure, and other feelings of that 
 sort. For an appcaa-Trjfjia is a disease accompanied with weak- 
 ness; and a disease is an opinion of something which appears ex- 
 ceedingly desirable. And, as in the case of the body, there are 
 illnesses to which people are especially liable, such as colds or 
 diarrhoea; so also are there propensities which the mind is under 
 the influence of, such as enviousness, pitifulness, quarrelsome- 
 ness, and so on. 
 
 There are also three good dispositions of the mind; joy, 
 caution, and will. And joy they say is the opposite of pleasure, 
 since it is a rational elation of the mind; so caution is the oppo- 
 site of fear, being a rational avoidance of anything, for the wise 
 man will never be afraid, but he will act with caution; and will, 
 they define as the opposite of desire, since it is a rational wish. 
 As therefore some things fall under the class of the first per- 
 turbations, in the same manner do some things fall under the 
 class of the first good dispositions. And accordingly, under the 
 head of will, are classed goodwill, placidity, salutation, affec- 
 tion ; and under the head of caution are ranged reverence and 
 modesty; under the head of joy, we speak of delight, mirth, 
 and good spirits. 
 
 * Horn. II. I. 81. Pope's Version, 1. 105.
 
 EPICURUS 
 
 (341-270) 
 
 FROM DIOGENES LAERTIUS' LIVES AND 
 
 OPINIONS OF EMINENT 
 
 PHILOSOPHERS 
 
 Translated from the Greek by 
 CHARLES D. YONGE 
 
 BOOK X. THE EPICUREAN PSYCHOLOGY 
 
 XX. Now, in the Canon, Epicurus says that the criteria of 
 truth are the senses, the preconceptions, and the passions. But 
 the Epicureans, in general, add also the perceptive impressions 
 of the intellect. And he says the same thing in his Abridg- 
 ment, which he addresses to Herodotus, and also in his Funda- 
 mental Principles. For, says he, the senses are devoid of reason, 
 nor are they capable of receiving any impressions of memory. 
 For they are not by themselves the cause of any motion, and 
 when they have received any impression from any external 
 cause, then they can add nothing to it, nor can they subtract 
 anything from it. Moreover, they are out of the reach of any 
 control; for one sensation cannot judge of another which re- 
 sembles itself; for they have all an equal value. Nor can one 
 judge of another which is different from itself; since their ob- 
 jects are not identical. In a word, one sensation cannot control 
 another, since the effects of all of them influence us equally. 
 Again, the reason cannot pronounce on the senses; for we have 
 already said that all reasoning has the senses for its foundation. 
 Reality and the evidence of sensation establish the certainty of 
 the senses; for the impressions of sight and hearing are just as 
 real, just as evident, as pain. 
 
 It follows from these considerations that we ought to judge 
 of things which are obscure by their analogy to those which
 
 90 EPICURUS 
 
 we perceive directly. In fact, every notion proceeds from the 
 senses, either directly, or in consequence of some analogy, or 
 proportion, or combination. Reasoning having always a share 
 in these last operations. The visions of insanity and of sleep 
 have a real object, for they act upon us; and that which has no 
 reality can produce no action. 
 
 XXI. By preconception, the Epicureans mean a sort of 
 comprehension as it were, or right opinion, or notion, or general 
 idea which exists in us; or, in other words, the recollection of an 
 external object often perceived anteriorly. Such for instance, is 
 this idea: "Man is a being of such and such a nature." At the 
 same moment that we utter the word man, we conceive the fig- 
 ure of a man, in virtue of a preconception which we owe to the 
 preceding operations of the senses. Therefore, the first notion 
 which each word awakens in us is a correct one; in fact, we could 
 not seek for anything if we had not previously some notion of 
 it. To enable us to affirm that what we see at a distance is a 
 horse or an ox, we must have some preconception in our 
 minds which makes us acquainted with the form of a horse 
 and an ox. We could not give names to things, if we had not 
 a preliminary notion of what the things were. 
 
 XXII. These preconceptions then furnish us with certainty. 
 And with respect to judgments, their certainty depends on our 
 referring them to some previous notion, of itself certain, in virtue 
 of which we affirm such and such a judgment; for instance, 
 " How do we know whether this thing is a man? " 
 
 The Epicureans call opinion (So'a) also supposition (VTTO- 
 X?7i/ri<?). And say that it is at times true, and at times false; for 
 that, if it is supported by testimony, and not contradicted by 
 testimony, then it is true; but if it is not supported by testi- 
 mony, and is contradicted by testimony, then it is false. On 
 which account they have introduced the expression of " wait- 
 ing," as if, before pronouncing that a thing seen is a tower, we 
 must wait till we come near, and learn what it looks like when 
 we are near it. 
 
 XXIII. They say that there are two passions, pleasure and 
 pain, which affect everything alive. And that the one is natural,
 
 DIOGENES LAERTIUS' LIVES 91 
 
 and the other foreign to our nature; with reference to which all 
 objects of choice and avoidance are judged of. They say also, 
 that there are two kinds of investigation; the one about facts, 
 the other about mere words. And this is as far as an element- 
 ary sketch can go their doctrine about division, and about 
 the criterion. 
 XXIV. Let us now go to the letter: 
 
 EPICURUS TO HERODOTUS, WISHING HE MAY DO WELL 
 
 "MOREOVER, there are images resembling, as far as their 
 form goes, the solid bodies which we see, but which differ mater- 
 ially from them in the thinness of their substance. In fact it is 
 not impossible but that there may be in space some secretions 
 of this kind, and an aptitude to form surfaces without depth, and 
 of an extreme thinness; or else that from the solids there may 
 emanate some particles which preserve the connection, the dis- 
 position, and the motion which they had in the body. I give 
 the name of images to these representations; and, indeed, their 
 movement through the vacuum taking place, without meeting 
 any obstacle or hindrance, perfects all imaginable extent in an 
 inconceivable moment of time; for it is the meeting of obsta- 
 cles, or the absence of obstacles, which produces the rapidity 
 or the slowness of their motion. At all events, a body in motion 
 does not find itself, at any moment imaginable, in two places at 
 the same time; that is quite inconceivable. From whatever 
 point of infinity it arrives at some appreciable moment, and 
 whatever may be the spot in its course in which we perceive its 
 motion, it has evidently quitted that spot at the moment of our 
 thought; for this motion which, as we have admitted up to this 
 point, encounters no obstacle to its rapidity, is wholly in the 
 same condition as that the rapidity of which is diminished by 
 the shock of some resistance. 
 
 "It is useful, also, to retain this principle, and to know that 
 the images have an incomparable thinness; which fact indeed 
 is in no respect contradicted by sensible appearances. From 
 which it follows that their rapidity also is incomparable; for
 
 92 EPICURUS 
 
 they find everywhere an easy passage, and besides, their infinite 
 smallness causes them to experience no shock, or at all events 
 to experience but a very slight one, while an infinite multitude 
 of elements very soon encounter some resistance. 
 
 "One must not forget that the production of images is simul- 
 taneous with the thought; for from the surface of the bodies 
 images of this kind are continually flowing off in an insensible 
 manner indeed, because they are immediately replaced. They 
 preserve for a long time the same disposition, and the same 
 arrangement that the atoms do in the solid body, although, not- 
 withstanding, their form may be sometimes altered. The direct 
 production of images in space is equally instantaneous, because 
 these images are only light substances destitute of depth. 
 
 "But there are other manners in which natures of this kind 
 are produced; for there is nothing in all this which at all contra- 
 dicts the senses, if one only considers in what way the senses 
 are exercised, and if one is inclined to explain the relation 
 which is established between external objects and ourselves. 
 Also, one must admit that something passes from external 
 objects into us in order to produce in us sight and the knowledge 
 of forms; for it is difficult to conceive that external objects can 
 affect us through the medium of the air which is between us 
 and them, or by means of rays, whatever emissions proceed 
 from us to them, so as to give us an impression of their form and 
 colour. This phenomenon, on the contrary, is perfectly ex- 
 plained, if we admit that certain images of the same colour, of 
 the same shape, and of a proportionate magnitude pass from 
 these objects to us, and so arrive at being seen and compre- 
 hended. These images are animated by an exceeding rapidity, 
 and, as on the other side, the solid object forming a compact 
 mass, and comprising a vast quantity of atoms, emits always 
 the same quantity of particles, the vision is continued, and only 
 produces in us one single perception which preserves always the 
 same relation to the object. Every conception, every sensible 
 perception which bears upon the form or the other attributes 
 of these images, is only the same form of the solid perceived 
 directly, either in virtue of a sort of actual and continued con-
 
 DIOGENES LAERTIUS' LIVES 93 
 
 densation of the image, or in consequence of the traces which 
 it has left in us. 
 
 "Error and false judgments always depend upon the suppo- 
 sition that a preconceived idea will be confirmed, or at all 
 events will not be overturned, by evidence. Then, when it is 
 not confirmed, we form our judgment in virtue of a sort of 
 initiation of the thoughts connected, it is true with the per- 
 ception, and with a direct representation; but still connected 
 also with a conception peculiar to ourselves, which is the parent 
 of error. In fact the representations which intelligence reflects 
 like a mirror, whether one perceives them in a dream, or by any 
 other conceptions of the intellect, or of any other of the criteria, 
 can never resemble the objects that one calls real and true, un- 
 less there were objects of this kind perceived directly. And, on 
 the other side, error could not be possible, if we did not receive 
 some other motion also, a sort of initiative of intelligence con- 
 nected; it is true with direct representation, but going beyond 
 that representative. These conceptions being connected with 
 the direct perception which produces the representation, but 
 going beyond it, in consequence of a motion peculiar to the 
 individual thought, produces error when it is not confirmed by 
 evidence, or when it is contradicted by evidence; but when it is 
 confirmed, or when it is not contradicted by evidence, then it 
 produces truth. 
 
 "We must carefully preserve these principles in order not to 
 reject the authority of the faculties which perceive truth di- 
 rectly; and not, on the other hand, to allow what is false to be 
 established with equal firmness, so as to throw everything into 
 confusion. 
 
 "Let us now return to the study of the affections, and of the 
 sensations; for this will be the best method of proving that the 
 soul is a bodily substance composed of slight particles, diffused 
 over all the members of the body, and presenting a great anal- 
 ogy to a sort of spirit, having an admixture of heat, resembling 
 at one time one, and at another time the other of those two 
 principles. There exists in it a special part, endowed with an
 
 94 EPICURUS 
 
 extreme mobility, in consequence of the exceeding slightness of 
 the elements which compose it, and also in reference to its 
 more immediate sympathy with the rest of the body. That it is 
 which the faculties of the soul sufficiently prove, and the pas- 
 sions, and the mobility of its nature, and the thoughts, and, in a 
 word, everything, the privation of which is death. We must 
 admit that it is in the soul most especially that the principle 
 of sensation resides. At the same time, it would not possess 
 this power if it were not enveloped by the rest of the body which 
 communicates it to it, and in its turn receives it from it; but 
 only in a certain measure; for there are certain affections of the 
 soul of which it is not capable. 
 
 "It is on that account that, when the soul departs, the body 
 is no longer possessed of sensation; for it has not this power, 
 (that of sensation namely) in itself; but, on the other hand, 
 this power can only -manifest itself in the soul through the 
 medium of the body. The soul, reflecting the manifestations 
 which are accomplished in the substance which environs it, 
 realises in itself, in a virtue or power which belongs to it, the 
 sensible affections, and immediately communicates them to the 
 body in virtue of the reciprocal bonds of sympathy which unite 
 it to the body; that is the reason why the destruction of a part 
 of the body does not draw after it a cessation of all feeling in 
 the soul while it resides in the body, provided that the senses 
 still preserve some energy; although, nevertheless, the disso- 
 lution of the corporeal covering, or even of any one of its por- 
 tions, may sometimes bring on with it the destruction of the 
 soul. 
 
 "The rest of the body, on the other hand, even when it re- 
 mains, either as a whole, or in any part, loses all feeling by the 
 dispersion of that aggregate of atoms, whatever it may be, that 
 forms the soul. When the entire combination of the body is 
 dissolved, then the soul too is dissolved, and ceases to retain 
 those faculties which were previously inherent in it, and espe- 
 cially the power of motion; so that sensation perishes equally 
 as far as the soul is concerned; for it is impossible to imagine 
 that it still feels, from the moment when it is no longer in the
 
 DIOGENES LAERTIUS' LIVES 95 
 
 same conditions of existence, and no longer possesses the same 
 movements of existence in reference to the same organic sys- 
 tem ; from the moment, in short, when the things which cover 
 and surround it are no longer such, that it retains in them the 
 same movements as before. 
 
 (Epicurus expresses the same ideas in other works, and adds 
 that the soul is composed of atoms of the most perfect light- 
 ness and roundness; atoms wholly different from those of fire. 
 He distinguishes in it the irrational part which is diffused over 
 the whole body, from the rational part which has its seat in 
 the chest, as is proved by the emotions of fear and joy. He 
 adds that sleep is produced when the parts of the soul diffused 
 over the whole of the body concentre themselves, or when they 
 disperse and escape by the pores of the body; for particles ema- 
 nate from all bodies.) 
 
 "It must also be observed, that I use the word incorporeal 
 (acrco/iaro?) in the usual acceptation of the word, to express 
 that which is in itself conceived as such. Now, nothing can 
 be conceived in itself as incorporeal except the vacuum; but 
 the vacuum cannot be either passive or active; it is only the 
 condition and the place of movement. Accordingly, they who 
 pretend that the soul is incorporeal, utter words destitute of 
 sense; for, if it had this character, it would not be able either 
 to do or to suffer anything; but, as it is, we see plainly enough 
 that it is liable to both these circumstances. 
 
 "Let us then apply all these reasonings to the affections and 
 sensations, recollecting the ideas which we laid down at the 
 beginning, and then we shall see clearly that these general 
 principles contain an exact solution of all the particular cases. 
 
 "As to forms, and hues, and magnitudes, and weight, and the 
 other qualities which one looks upon as attributes, whether it 
 be of every body, or of those bodies only which are visible and 
 perceived by the senses, this is the point of view under which 
 they ought to be considered : they are not particular sub- 
 stances, having a peculiar existence of their own, for that can- 
 not be conceived; nor can one say any more that they have no 
 reality at all. They are not incorporeal substances inherent in
 
 96 EPICURUS 
 
 the body, nor are they parts of the body. But they constitute 
 by their union the eternal substance and the essence of the en- 
 tire body. We must not fancy, however, that the body is com- 
 posed of them, as an aggregate is formed of particles of the 
 smallest dimensions of atoms or magnitudes, whatever they 
 may be, smaller than the compound body itself; they only con- 
 stitute by their union, I repeat, the eternal substance of the 
 body. Each of these attributes has ideas and particular per- 
 ceptions which correspond to it; but they cannot be perceived 
 independently of the whole subject taken entirely; the union 
 of all these perceptions forms the idea of the body. Bodies often 
 possess other attributes which are not eternally inherent in 
 them, but which, nevertheless, cannot be ranged among the 
 incorporeal and invisible things. Accordingly, it is sufficient to 
 express the general idea of the movement of transference to en- 
 able us to conceive in a moment certain distinct qualities, and 
 those combined beings, which, being taken in their totality, 
 receive the name of bodies; and the necessary and eternal at- 
 tributes without which the body cannot be conceived. 
 
 "There are certain conceptions corresponding to these attri- 
 butes; but, nevertheless, they cannot be known abstractedly, 
 and independently of some subjects; and further, inasmuch 
 as they are not attributes necessarily inherent in the idea of a 
 body, one can only conceive them in the moment in which 
 they are visible; they are realities nevertheless; and one must 
 not refuse to them an existence merely because they have 
 neither the characteristic of the compound beings to which we 
 give the name of bodies, nor that of the eternal attributes. We 
 should be equally deceived if we were to suppose that they have 
 a separate and independent existence; for that is true neither of 
 them nor of the eternal attributes. They are, as one sees plainly, 
 accidents of the body; accidents which do not of necessity make 
 any part of its nature; which cannot be considered as indepen- 
 dent substances, but still to each of which sensation gives the 
 peculiar character under which it appears to us."
 
 TITUS LUCRETIUS GARUS 
 
 (95-50 
 
 ON THE NATURE OF THINGS 
 
 Translated from the Latin * by 
 H. A.J. MUNRO 
 
 BOOK III. THE MIND 
 
 FIRST then I say that the mind which we often call the un- 
 derstanding, in which dwells the directing and governing prin- 
 ciple of life, is no less part of the man, than hand and foot and 
 eyes are parts of the whole living creature. [Some however 
 affirm] that the sense of the mind does not dwell in a distinct 
 part, but is a certain vital state of the body, which the Greeks 
 call harmonia, because by it, they say, we live with sense, though 
 the understanding is in no one part; just as when good health 
 is said to belong to the body, though yet it is not any one part 
 of the man in health. In this way they do not assign a distinct 
 part to the sense of the mind; in all which they appear to me 
 to be grievously at fault in more ways than one. Oftentimes the 
 body which is visible to sight, is sick, while yet we have pleasure 
 in another hidden part; and oftentimes the case is the very 
 reverse, the man who is unhappy in mind feeling pleasure in his 
 whole body; just as if, while a sick man's foot is pained, the 
 head meanwhile should be in no pain at all. Moreover when 
 the limbs are consigned to soft sleep and the burdened body lies 
 diffused without sense, there is yet a something else in us which 
 during that time is moved in many ways and admits into it all 
 
 * From T. Lucretii Can De Rerum Natura libri sex. Reprinted from Lu- 
 cretius' On the Nature of Things, translated by H. A. J. Munro, London, 
 1864; '86.
 
 98 LUCRETIUS 
 
 the motions of joy and unreal cares of the heart. Now that you 
 may know that the soul as well is in the limbs and that the 
 body is not wont to have sense by any harmony, this is a main 
 proof: when much of the body has been taken away, still life 
 often stays in the limbs; and yet the same life, when a few 
 bodies of heat have been dispersed abroad and some air has 
 been forced out through the mouth, abandons at once the veins 
 and quits the bones : by this you may perceive that all bodies 
 have not functions of like importance nor alike uphold exist- 
 ence, but rather that those seeds which constitute wind and 
 heat, cause life to stay in the limbs. Therefore vital heat and 
 wind are within the body and abandon our frame at death. 
 Since then the nature of the mind and that of the soul have been 
 proved to be a part as it were of the man, surrender the name 
 of harmony, whether brought down to musicians from high 
 Helicon, or whether rather they have themselves taken it from 
 something else and transferred it to that thing which then was 
 in need of a distinctive name; whatever it be, let them keep it: 
 do you take in the rest of my precepts. 
 
 Now I assert that the mind and the soul are kept together 
 in close union and make up a single nature, but that the direct- 
 ing principle which we call mind and understanding, is the head 
 so to speak and reigns paramount in the whole body. It has a 
 fixed seat in the middle region of the breast : here throb fear and 
 apprehension, about these spots dwell soothing joys; therefore 
 here is the understanding or mind. All the rest of the soul dis- 
 seminated through the whole body obeys and moves at the will 
 and inclination of the mind. It by itself alone knows for itself, 
 rejoices for itself, at times when the impression does not move 
 either soul or body together with it. And as when some part 
 of us, the head or the eye, suffers from an attack of pain, we do 
 not feel the anguish at the same time over the whole body, thus 
 the mind sometimes suffers pain by itself or is inspirited with 
 joy. when all the rest of the soul throughout the limbs and 
 frame is stirred by no novel sensation. But when the mind is 
 excited by some more vehement apprehension, we see the whole 
 soul feel in unison through all the limbs, sweats and paleness
 
 ON THE NATURE OF THINGS 99 
 
 spread over the whole body, the tongue falter, the voice die 
 away, a mist cover the eyes, the ears ring, the limbs sink un- 
 der one; in short we often see men drop down from terror of 
 mind; so that anybody may easily perceive from this that the 
 soul is closely united with the mind, and, when it has been 
 smitten by the influence of the mind, forthwith pushes and 
 strikes the body. 
 
 This same principle teaches that the nature of the mind and 
 soul is bodily; for when it is seen to push the limbs, rouse the 
 body from sleep, and alter the countenance and guide and turn 
 about the whole man, and when we see that none of these 
 effects can take place without touch nor touch without body, 
 must we not admit that the mind and the soul are of a bodily 
 nature? Again you perceive that our mind in our body suffers 
 together with the body and feels in unison with it. When a 
 weapon with a shudder-causing force has been driven in and has 
 laid bare bones and sinews within the body, if it does not take 
 life, yet there ensues a faintness and a lazy sinking to the 
 ground and on the ground the turmoil of mind which arises, and 
 sometimes a kind of undecided inclination to get up. Therefore 
 the nature of the mind must be bodily, since it suffers from 
 bodily weapons and blows. 
 
 I will now go on to explain in my verses of what kind of body 
 the mind consists and out of what it is formed. First of all I say 
 that it is extremely fine and formed of exceedingly minute 
 bodies. That this is so you may, if you please to attend, clearly 
 perceive from what follows: nothing that is seen takes place 
 with a velocity equal to that of the mind when it starts some 
 suggestion and actually sets it agoing; the mind therefore is 
 stirred with greater rapidity than any of the things whose na- 
 ture stands out visible to sight. But that which is so passing 
 nimble, must consist of seeds exceedingly round and exceed- 
 ingly minute, in order to be stirred and set in motion by a small 
 moving power. Thus water is moved and heaves by ever so 
 small a force, formed as it is of small particles apt to roll. But 
 on the other hand the nature of honey is more sticky, its liquid 
 more sluggish and its movement more dilatory; for the whole
 
 ioo LUCRETIUS 
 
 mass of matter coheres more closely, because sure enough it is 
 made of bodies not so smooth, fine and round. A breeze how- 
 ever gentle and light can force, as you may see, a high heap of 
 poppy seed to be blown away from the top downwards ; but on 
 the other hand eurus itself cannot move a heap of stones. 
 Therefore bodies possess a power of moving in proportion to 
 their smallness and smoothness; and on the other hand the 
 greater weight and roughness bodies prove to have, the more 
 stable they are. Since then the nature of the mind has been 
 found to be eminently easy to move, it must consist of bodies 
 exceedingly small, smooth and round. The knowledge of which 
 fact, my good friend, will on many accounts prove useful and 
 be serviceable to you. The following fact too likewise demon- 
 strates how fine the texture is of which its nature is composed, 
 and how small the room is in which it can be contained, could it 
 only be collected into one mass: soon as the untroubled sleep of 
 death has gotten hold of a man and the nature of the mind and 
 soul has withdrawn, you can perceive then no diminution of the 
 entire body either in appearance or weight: death makes all 
 good save the vital sense and heat. Therefore the whole soul 
 must consist of very small seeds and be inwoven through veins 
 and flesh and sinews; inasmuch as, after it has all withdrawn 
 from the whole body, the exterior contour of the limbs preserves 
 itself entire and not a tittle of the weight is lost. Just in the 
 same way when the flavour of wine is gone or when the delicious 
 aroma of a perfume has been dispersed into the air or when the 
 savour has left some body, yet the thing itself does not there- 
 fore look smaller to the eye, nor does aught seem to have been 
 taken from the weight, because sure enough many minute seeds 
 make up the savours and the odour in the whole body of the 
 several things. Therefore, again and again I say, you are to 
 know that the nature of the mind and the soul has been formed 
 of exceedingly minute seeds, since at its departure it takes away 
 none of the weight. 
 
 We are not however to suppose that this nature is single. 
 For a certain subtle spirit mixed with heat quits men at death, 
 and then the heat draws air along with it ; there being no heat
 
 ON THE NATURE OF THINGS 101 
 
 which has not air too mixed with it: for since its nature is rare, 
 many first-beginnings of air must move about through it. Thus 
 the nature of the mind is proved to be threefold ; and yet these 
 things all together are not sufficient to produce sense ; since the 
 fact of the case does not admit that any of these can produce 
 sense-giving motions and the thoughts which a man turns over 
 in mind. Thus some fourth nature too must be added to these: 
 it is altogether without name; than it nothing exists more nim- 
 ble or more fine, or of smaller or smoother elements: it first 
 transmits the sense-giving motions through the frame; for it is 
 first stirred, made up as it is of small particles; next the heat 
 and the unseen force of the spirit receive the motions, then the 
 air; then all things are set in action, the blood is stirred, every 
 part of the flesh is filled with sensation ; last of all the feel- 
 ing is transmitted to the bones and marrow, whether it be one 
 of pleasure or an opposite excitement. No pain however can 
 lightly pierce thus far nor any sharp malady make its way in, 
 without all things being so thoroughly disordered that no room 
 is left for life and the parts of the soul fly abroad through all 
 the pores of the body. But commonly a stop is put to these 
 motions on the surface as it were of the body: for this reason 
 we are able to retain life. 
 
 Now though I would fain explain in what way these are 
 mixed up together, by what means united, when they exert 
 their powers, the poverty of my native speech deters me sorely 
 against my will: yet will I touch upon them and in summary 
 fashion to the best of my ability: the first-beginnings by their 
 mutual motions are interlaced in such a way that none of them 
 can be separated by itself, nor can the function of any go on 
 divided from the rest by any interval; but they are so to say the 
 several powers of one body. Even so in any flesh of living crea- 
 ture you please without exception there is smell and some 
 colour and a savour, and yet out of all these is made up one 
 single bulk of body. Thus the heat and the air and the unseen 
 power of the spirit mixed together produce a single nature, to- 
 gether with that nimble force which transmits to them from 
 itself the origin of motion ; by which means sense-giving motion
 
 102 LUCRETIUS 
 
 first takes its rise through the fleshly frame. For this nature 
 lurks secreted in its inmost depths, and nothing in our body 
 is farther beneath all ken than it, and more than this it is the 
 very soul of the whole soul. Just in the same way as the power 
 of the mind and the function of the soul are latent in our limbs 
 and throughout our body, because they are each formed of small 
 and few bodies: even so, you are to know, this nameless power 
 made of minute bodies is concealed and is moreover the very 
 soul so to say of the whole soul, and reigns supreme in the whole 
 body. On a like principle the spirit and air and heat must, as 
 they exert their powers, be mixed up together through .the 
 frame, and one must ever be more out of view or more promi- 
 nent than another, that a single substance may be seen to be 
 formed from the union of all, lest the heat and spirit apart by 
 themselves and the power of the air apart by itself should de- 
 stroy sense and dissipate it by their disunion; Thus the mind 
 possesses that heat which it displays when it boils up in anger 
 and fire flashes from the keen eyes; there is too much cold spirit 
 comrade of fear, which spreads a shivering over the limbs and 
 stirs the whole frame; yes and there is also that condition of 
 still air which has place when the breast is calm and the looks 
 cheerful. But they have more of the hot whose keen heart and 
 passionate mind lightly boil up in anger. Foremost in this class 
 comes the fierce violence of lions who often as they chafe break 
 their hearts with their roaring and cannot contain within their 
 breast the billows of their rage. Then the chilly mind of stags 
 is fuller of the spirit and more quickly rouses through all the 
 flesh its icy currents which cause a shivering motion to pass over 
 the limbs. But the nature of oxen has its life rather from the still 
 air, and never does the smoky torch of anger applied to it stimu- 
 late it too much, shedding over it the shadow of murky gloom, 
 nor is it transfixed and stiffened by the icy shafts of fear : it lies 
 between the other two, stags and cruel lions. And thus it is with 
 mankind: however much teaching renders some equally refined, 
 it yet leaves behind those earliest traces of the nature of each 
 mind; and we are not to suppose that evil habits can be so thor- 
 oughly plucked up by the roots, that one man shall not be more
 
 ON THE NATURE OF THINGS 103 
 
 prone than another to keen anger, a second shall not be some- 
 what more quickly assailed by fear, a third shall not take some 
 things more meekly than is right. In many other points there 
 must be differences between the varied natures of men and the 
 tempers which follow upon these; though at present I am unable 
 to set forth the hidden causes of these or to find names enough 
 for the different shapes which belong to the first-beginnings, 
 from which shapes arises this diversity of things. What herein 
 I think I may affirm is this: traces of the different natures left 
 behind, which reason is unable to expel from us, are so exceed- 
 ingly slight that there is nothing to hinder us from living a life 
 worthy of gods. 
 
 Well this nature is contained by the whole body and is in 
 turn the body's guardian and the cause of its existence; for the 
 two adhere together with common roots and cannot it is plain 
 be riven asunder without destruction. Even as it is not easy to 
 pluck the perfume out of lumps of frankincense without quite 
 destroying its nature as well; so it is not easy to withdraw from 
 the whole body the nature of the mind and soul without dis- 
 solving all alike. With first-beginnings so interlaced from their 
 earliest birth are they formed and gifted with a life of joint 
 partnership, and it is plain that the faculty of the body and of 
 the mind cannot feel separately, each alone without the other's 
 power, but sense is kindled throughout our flesh and blown into 
 flame between the two by the joint motions on the part of both. 
 Moreover the body by itself is never either begotten or grows 
 or, it is plain, continues to exist after death. For not in the way 
 that the liquid of water often loses the heat which has been 
 given to it, yet is not for that reason itself riven in pieces, but 
 remains unimpaired, not in this way, I say, can the aban- 
 doned frame endure the separation of the soul, but riven in 
 pieces it utterly perishes and rots away. Thus the mutual con- 
 nexions of body and soul from the first moment of their exist- 
 ence learn the vital motions even while hid in the body and 
 womb of the mother, so that no separation can take place with- 
 out mischief and ruin. Thus you may see that, since the cause 
 of existence lies in their joint action, their nature too must be 
 a joint nature.
 
 104 LUCRETIUS 
 
 Furthermore if any one tries to disprove that the body feels 
 and believes that the soul mixed through the whole body takes 
 upon it this motion which we name sense, he combats even 
 manifest and undoubted facts. For who will ever bring for- 
 ward any explanation of what the body's feeling is, except that 
 which the plain fact of the case has itself given and taught to 
 us? But when the soul it is said has departed, the body through- 
 out is without sense; yes, for it loses what was not its own pecul- 
 iar property in life; ay and much else it loses, before that soul 
 is driven out of it. 
 
 Again to say that the eyes can see no object, but that the 
 soul discerns through them as through an open door, is far from 
 easy, since their sense contradicts this; for this sense e'en draws 
 it and forces it out to the pupil : nay often we are unable to per- 
 ceive shining things, because our eyes are embarrassed by the 
 lights. But this is not the case with doors; for, because we our- 
 selves see, the open doors do not therefore undergo any fatigue. 
 Again if our eyes are in the place of doors, in that case when the 
 eyes are removed the mind ought it would seem to have more 
 power of seeing things, after doors, jambs and all, have been 
 taken out of the way. 
 
 And herein you must by no means adopt the opinion which 
 the revered judgment of the worthy manDemocritus lays down, 
 that the first-beginnings of body and mind placed together in 
 successive layers come in alternate order and so weave the tis- 
 sue of our limbs. For not only are the elements of the soul 
 much smaller than those of which our body and flesh are 
 formed, but they are also much fewer in number and are dis- 
 seminated merely in scanty number through the frame, so that 
 you can warrant no more than this: the first-beginnings of the 
 soul keep spaces between them at least as great as are the small- 
 est bodies which, if thrown upon it, are first able to excite in our 
 body the sense-giving motions. Thus at times we do not feel 
 the adhesion of dust when it settles on our body, nor the 
 impact of chalk when it rests on our limbs, nor do we feel a mist 
 at night nor a spider's slender threads as they come against us, 
 when we are caught in its meshes in moving along, nor the same
 
 ON THE NATURE OF THINGS 105 
 
 insect's flimsy web when it has fallen on our head, nor the 
 feathers of birds and down of plants as it flies about, which 
 commonly from exceeding lightness does not lightly fall, nor do 
 we feel the tread of every creeping creature whatsoever nor 
 each particular foot-print which gnats and the like stamp on our 
 body. So very many first-beginnings must be stirred in us, 
 before the seeds of the soul mixed up in our bodies feel that 
 these have been disturbed, and by thumping with such spaces 
 between can clash unite and in turn recoil. 
 
 The mind has more to do with holding the fastnesses of life 
 and has more sovereign sway over it than the power of the soul. 
 For without the understanding and the mind no part of the soul 
 can maintain itself in the frame the smallest fraction of time, 
 but follows at once in the other's train and passes away into the 
 air and leaves the cold limbs in the chill of death. But he abides 
 in life whose mind and understanding continue to stay with him : 
 though the trunk is mangled with its limbs shorn all round 
 about it, after the soul has been taken away on all sides and 
 been severed from the limbs the trunk yet lives and inhales the 
 ethereal airs of life. When robbed, if not of the whole, yet of a 
 large portion of the soul, it still lingers in and cleaves to life; just 
 as, after the eye has been lacerated all round if the pupil has 
 continued uninjured, the living power of sight remains, provided 
 always you do not destroy the whole ball of the eye and pare 
 close round the pupil and leave only it ; for that will not be done 
 even to the ball without the entire destruction of the eye. But 
 if that middle portion of the eye, small as it is, is eaten into, the 
 sight is gone at once and darkness ensues, though a man have 
 the bright ball quite unimpaired. On such terms of union soul 
 and mind are ever bound to each other.
 
 PLOTINUS 
 
 (205 Ajx-syo) 
 
 ENNEADES 
 
 Translated from the Greek*' by 
 THOMAS TAYLOR 
 
 VII. THE SOUL 
 (rv. vn) 
 
 I. WHETHER each [part] of us is immortal, or the whole 
 perishes, or one part of us is dissipated and corrupted, but an- 
 other part perpetually remains, which part is the man himself, 
 may be learned by considering conformably to nature as fol- 
 lows: Man, indeed, is not something simple, but there is in him 
 a soul, and he has also a body, whether it is annexed to us as an 
 instrument, or after some other manner. However this may be, 
 it must be admitted, that the nature and essence of each of 
 these must be thus divided. Since the body, therefore, is itself a 
 composite, reason shows that it cannot remain [perpetually the 
 same]. The senses likewise perceive that it is dissolved and 
 wastes away, and receives destructions of every sort; since each 
 of the things inherent in it tends to its own proper nature, and 
 one thing belonging to it corrupts another, and changes and 
 perishes into something else. This, too, is especially the case 
 when the soul, which causes the parts to be in friendly union 
 with each other, is not present with the corporeal mass. If each 
 body, likewise, is left by itself, it will not be one, since it is cap- 
 able of being dissolved into form and matter, from which it is 
 also necessary that simple bodies should have their composi- 
 tion. Moreover, as bodies they have magnitude, and conse- 
 quently may be cut and broken into the smallest parts, and 
 
 * From nXwrf vov "EvvedSet. Reprinted with verbal changes from Select Works 
 of Plotinus, translated by Thomas Taylor, London, 1817; ib., 1895.
 
 ENNEADES 107 
 
 for this reason are subject to corruption. Hence, if body is a 
 part of us, we are not wholly immortal. But if it is an instru- 
 ment [of the soul] it is necessary that being given for a certain 
 time, it should be naturally a thing of this kind. That, however, 
 which is the most principal thing, and the man himself, will be 
 that with reference to the body which form is with reference to 
 matter, since this according to form is as body to matter, 
 or according to that which uses, the body has the relation to it 
 of an instrument. But in either case the soul is the man himself. 
 
 II. What, therefore, is the nature of the soul? If indeed it is a 
 body, it is in every respect capable of being analyzed. For 
 every body is a composite. But if it is not a body, but of another 
 nature, that also must be considered, either after the same, or 
 after another manner. In the first place, [if the soul be corpo- 
 real], it must be considered into what this body which they call 
 soul ought to be analyzed. For since life is necessarily present 
 with soul, it is also necessary that this body which is supposed 
 to be soul, if it consists of two or more bodies, should have life 
 innate in both, or in each of them ; or that one of these should 
 have life, but the other not, or that neither should be vital. If, 
 therefore, life is present with one of them only, this very thing 
 will be soul. Hence, what body will this be which has life from 
 itself? For fire, air, water and earth, are of themselves inani- 
 mate; and with whichever of these soul is present, the life 
 which it uses is adventitious. There are not, however, any 
 other bodies besides these. And those to whom it appears that 
 there are other bodies which are the elements of these, do not 
 assert that they are souls, or that they have life. 
 
 But if it should be said, that though no one of these bodies 
 possesses life, yet the conjunction of them produces life, one 
 would speak absurdly. And if each of them has life, one will be 
 sufficient. Or rather, it is impossible that a combination of 
 bodies should produce life, and things void of intellect generate 
 intellect. Moreover, neither will these, in whatever manner 
 they may say they are mixed, generate either intellect or soul. 
 Hence, it is necessary there should be that which arranges, and 
 which is the cause of the mixture; so that this will have the
 
 io8 PLOTINUS. 
 
 order of soul. For that which is compounded cannot be that 
 which arranges and produces the mixture. But neither can 
 there be a simple body in the series of things, without the exist- 
 ence of soul in the universe; if reason [or a productive principle] 
 entering into matter, produces body. For reason cannot pro- 
 ceed from any thing else than from soul. 
 
 III. . . . Indeed, neither will there be any body, if there is 
 no psychical power. For body [perpetually] flows, and its na- 
 ture is in [continual] motion. The universe would rapidly perish 
 if all things were bodies; though some one of them should be 
 denominated "soul." For it would suffer the same things as 
 other bodies, since there would be one matter in all of them. 
 Or rather, nothing would be generated, but all things would 
 remain mere matter, as there would not be any thing to invest 
 it with form. Perhaps, too, neither would matter have any sub- 
 sistence whatever. This universe also would be dissolved, if it 
 is committed to the connexion of body, and the order of soul is 
 given to body, as far as the name went, ascribing it to air and 
 dissoluble spirits, which have not of themselves any unity. For 
 how is it possible, since all bodies are divisible, that this uni- 
 verse if it is committed to any one of them, should not be borne 
 along in a foolish and casual manner? What order is there, or 
 reason or intellect, in a pneumatic substance, which is in want 
 of order from soul? But if soul, indeed, has a subsistence, all 
 these will be subservient to it in the composition of the world, 
 and in the existence of every animal, in that one power arising 
 from another contributes to [the perfection of] the whole. If 
 soul, however, is not present to the whole of things, these 
 will neither have a subsistence, nor any arrangement. 
 
 VI. But that if soul is body, there would be no sensation, nor 
 thought, nor undertaking, nor virtue, nor any thing beautiful [in 
 human conduct,] will be manifest from the following considera- 
 tions. Whatever is able to have a sensible perception of any 
 thing, ought itself to be one, and to apprehend every thing by 
 one and the same power.- This will also be the case, if many 
 things enter through many organs of sense, or there are many 
 qualities about one thing, and likewise when there is a varie-
 
 ENNEADES 109 
 
 gated appearance such as that of the face, through one thing. 
 For one thing does not perceive the nose, and another the eyes, 
 but the same thing perceives at once all the parts of the face. 
 And though one sensation proceeds through the eyes, but an- 
 other through the ears, yet it is necessary there should be some 
 one thing at which both arrive. Or how could the soul say that 
 these are different, unless the perceptions of sense at once ter- 
 minated in the same thing? It is necessary, therefore, that this 
 should be as it were a centre, that the senses should on all sides 
 be extended to this, like lines from the circumference of a circle, 
 and that a thing of this kind which apprehends the perceptions 
 of sense should be truly one. . . . 
 
 VII. The same thing also may be seen from pain and the 
 sensation of pain; when a man is said to have a pain in or about 
 his finger. For then it is manifest that the sensation of pain is 
 produced in the principal or ruling part. A portion of the spirit 
 being pained, the ruling part has a perception of the pain, and the 
 whole soul in consequence of this suffers the same pain. How, 
 therefore, does this happen? They will say by transmission, 
 the psychical spirit about the finger suffering in the first place, 
 but imparting the passion to that which is next to it, and after- 
 wards to something else, until the passion arrives at the ruling 
 part. Hence, it is necessary if that which is primarily pained 
 perceives, that there should be another sensation of that which 
 is second, provided sensation is produced by transmission. Like- 
 wise, it is necessary that there should be another sensation of 
 that which is the third in order; that there should be many and 
 infinite sensible perceptions of one and the same pain ; and that 
 afterwards all these should be perceived by the ruling part, and 
 besides these, that it should have a perception of its own passion. 
 In reality, however, each of these does not perceive the pain 
 that is in the finger; but one sensation perceives that the part 
 of the palm of the hand which is next to the finger is pained, 
 and another more remote sensation perceives the pain which is 
 in a more remote part. 
 
 There will also be many pains, the ruling faculty not perceiv- 
 ing the passion which is in the finger, but that which is present
 
 no PLOTINUS 
 
 with itself. And this it will alone know, but will bid farewell to 
 the others, not perceiving that the finger is pained. It, therefore, 
 is not possible that sensible perception of a thing of this kind 
 should subsist according to transmission. Nor can any one part 
 of the body which is an extended mass be aware of another's 
 suffering, since in every magnitude the parts are distinct. If this 
 be the case, it is necessary that the perceiving faculty should be 
 of such a nature, as to be every where identical with itself. But 
 this pertains to any thing else rather than to body. 
 
 VIII. Moreover, that it would be impossible to perceive 
 intellectually if the soul is body, may be demonstrated as fol- 
 lows. For if to perceive sensibly is, for the soul using the body 
 to apprehend sensible objects, intellectual perception will not 
 be an apprehension of the objects of such perception, through 
 body. For unless this is admitted, intellectual will be the same 
 with sensible perception. Hence, if to perceive intellectually is 
 to apprehend without body, by a much greater priority it is 
 necessary that the nature which thus perceives should not be 
 body. Farther still, if sense indeed is the perception of sensible 
 objects, intellection is the perception of intelligible objects. If, 
 however, they are not willing to admit this, yet there must be 
 in us thoughts of certain intelligible objects, and apprehensions 
 of things without magnitude. How, therefore, will intellect if it 
 is magnitude, understand that which is not magnitude, and 
 with its divisible nature, think that which is indivisible? Shall 
 we say it will understand it by a certain indivisible part of itself? 
 But if this be the case, that which understands will not be body. 
 For there is no need of the whole in order to come into contact 
 with the object of its thought; since contact of a single part is 
 sufficient. 
 
 If, therefore, they admit that the most abstract thoughts 
 are entirely liberated from body, it is necessary that the nature 
 which intellectually perceives the form separate from body of 
 each thing, should know either real being, or that which is be- 
 coming pure. But if they say that thoughts are of forms in- 
 herent in matter, yet they are then only apprehended when by 
 intellect they are separated from body. For the separation [i.e.
 
 ENNEADES 
 
 in 
 
 abstraction] of a circle and triangle, of a line and a point, is not 
 effected in conjunction with flesh, or in short, with matter. 
 Hence it is necessary that the soul also, in a separation of this 
 kind, should separate itself from the body. And therefore it is 
 necessary that it should not be itself body. I think, likewise, 
 that the beautiful and the just are without magnitude, and 
 consequently the thought of these is unattended with magni- 
 tude. Hence, these approaching to us are apprehended by that 
 which is indivisible in the soul, and in the soul they reside in the 
 indivisible. How also, if the soul is body, can temperance and 
 justice be the virtues of it, which are its saviours, so far as they 
 are received by it? 
 
 IX. There must, therefore, be another nature which pos- 
 sesses existence from itself, and such is every thing which is 
 truly being, a-nd which is neither generated, nor destroyed. For 
 without the subsistence of this, all things would vanish into 
 non-entity, and this perishing, would not afterwards be gener- 
 ated ; since this imparts safety to all other things, and also to 
 the universe which through soul is preserved and adorned. For 
 soul is the principle of motion, with which it supplies other 
 things, itself moving itself, and imparting life to the animated 
 body. But it possesses life from itself, which it will never lose, 
 because it is derived from itself. For all things do not use an 
 adventitious life, or there would be a progression of life to 
 infinity. But it is necessary there should be a certain nature 
 primarily vital, which is also necessarily indestructible and 
 immortal, as being the principle of life to other things. . . . 
 
 X. That the soul, however, is allied to a more divine and 
 eternal nature, is evident from its not being body as we have 
 demonstrated, and also because it has neither figure nor colour. 
 Moreover, this likewise may be shown from the following con- 
 siderations. It is acknowledged by all of us, that every divine 
 nature, and one which is truly being, enjoys an excellent and 
 wise life. This, therefore, being admitted, it is necessary to 
 consider in the next place, what is the nature of our soul. We 
 must assume the soul, however, not as receiving in the body 
 irrational desires and angers, and other passions, but as abolish-
 
 ii2 PLOTINUS 
 
 ing all these, and as much as possible having no communication 
 with the body. For such a soul as this will clearly show that 
 evils are an addition to the soul, and are externally derived; 
 and that the most excellent things are inherent in it when it is 
 purified, viz. wisdom and every other virtue, which are its 
 proper possessions. 
 
 If, therefore, the soul is such when it returns to itself, how is 
 it possible it should not belong to that nature which we say is 
 possessed by every thing eternal and divine? For wisdom and 
 true virtue being divine, cannot be inherent in any vile and 
 mortal thing; but that which is of this kind is necessarily divine, 
 as being full of divine goods, through an alliance and similitude 
 of essence to a divine nature. Hence, whoever of us resembles a 
 soul of this description, will in soul itself differ but little from 
 superior beings; in this alone being inferior to them, that he is 
 in body. On which account, also, if every man was such, or if 
 the multitude employed souls of this kind, no one would be so 
 incredulous as not to believe that our soul is entirely immortal. 
 
 XII. Farther still, if they say that every soul is corruptible, 
 it would be requisite that all things should have long since per- 
 ished. But if they assert that one soul is corruptible, and an- 
 other not, as for instance, that the soul of the universe is im- 
 mortal, but ours not, it is necessary that they should assign the 
 cause of this difference. For each is the cause of motion, and each 
 lives from itself. Each, likewise, comes into contact with the 
 same things by the same power, intellectually perceiving the 
 natures in the heavens, and also those that are beyond the heav- 
 ens, investigating everything which has an essential subsist- 
 ence, and ascending as far as to the first principle of things. To 
 which may be added, that it is evident the soul gave being to 
 itself prior to the body, from its ability of apprehending what 
 each thing is, by itself, from its own inherent spectacles, and 
 from reminiscence. And from its employing eternal sciences, 
 it is manifest that it is itself perpetual. 
 
 Besides, since everything which can be dissolved receives 
 composition, hence, so far as a thing is a composite, it is natur- 
 ally adapted to be dissolved. But soul being one simple energy,
 
 ENNEADES 113 
 
 and a nature characterized by life, cannot be corrupted as a 
 composite. Will it, therefore, through being divided and dis- 
 tributed into minute parts, perish? Soul, however, is not, as 
 we have demonstrated, a certain bulk or quantity. May it not, 
 therefore, through being changed in quality, be corrupted? 
 Change in quality however which corrupts takes away form, 
 but leaves the subject matter. But this is the nature of a com- 
 posite. Hence, if it is not possible for the soul to be corrupted 
 according to any of these modes, it is necessarily incorruptible. 
 
 VIII. THE INTELLECT 
 
 (v. i.) 
 
 III. Hence, as the soul is so honourable and divine a thing, 
 now confiding in a cause of this kind, ascend with it to divinity. 
 For you will not be very distant from him ; nor are the intermed- 
 iate natures many. In this, therefore, which is divine, receive 
 that part which is more divine, viz. the vicinity of the soul to 
 that which is supernal, to which the soul is posterior, and from 
 which it proceeds. For though it is so great a thing as we have 
 demonstrated it to be, yet it is a certain image of intellect. And, 
 just as external discourse is an image of the discursive energy 
 within the soul, after the same manner, soul, and the whole of 
 its energy, are the thought of intellect, and a life which it emits 
 in order to the hypostasis of another thing. It is just as in fire, 
 where the inherent heat of it is one thing, and the heat which it 
 imparts another. It is necessary, however, to assume there, not 
 a life flowing forth, but partly abiding in intellect, and partly 
 giving subsistence to another life. Hence, since soul is derived 
 from intellect, it is intellectual, and the intellect of soul is con- 
 versant with discursive energies. 
 
 Again, the perfection of soul is from intellect, as from a father 
 that nourishes it, who generated soul, as with reference to him- 
 self, not perfect. This hypostasis, therefore, is from intellect, 
 and is also reason in energy when it perceives intellect. For 
 when it looks to intellect, it possesses internally, and appro- 
 priately, the things which it understands, and the energies which
 
 ii 4 PLOTINUS 
 
 it performs. And it is necessary to call those energies alone the 
 energies of the soul, which are intellectual and dwell with it. 
 But its subordinate energies have an external source, and are 
 the passions of a soul of this kind. 
 
 Intellect, therefore, causes the soul to be more divine, both 
 because it is the father of it, and because it is present with it. 
 For there is nothing between them, except the difference of one 
 with reference to the other; soul being successive to, and the 
 recipient of intellect, but intellect subsisting as form. The mat- 
 ter also of intellect is beautiful, since it has the form of intellect, 
 and is simple. The great excellence, however, of intellect, is 
 manifest from this, that though soul is such as we have de- 
 scribed it to be, yet it is surpassed by intellect. 
 
 TX. 
 
 (v. xi.) 
 
 IV. Why, therefore, is it necessary to ascend to soul, and yet 
 not admit that it is the first of things? Is it not because in the 
 first place, indeed, intellect is different from, and more excellent 
 than soul? But that which is more excellent is prior by nature. 
 For soul when perfect, does not, as some fancy it does, generate 
 intellect. For whence will that which is in capacity become in 
 energy, unless there is a cause which leads into energy? Since 
 if it becomes in energy casually, it is possible that it may not 
 proceed into energy. Hence, it is necessary that first natures 
 should be established in energy, and that they should be want- 
 ing nothing and perfect. But imperfect natures are posterior to 
 them. The progeny also of imperfect, are perfected by first 
 natures, who after the manner of fathers give perfection to 
 what posterior natures generated imperfect from the beginning. 
 That, likewise, which is generated, has at first the relation of 
 matter to the maker of it, but is afterwards rendered perfect by 
 the participation of form. But if it is necessary that soul should 
 be connected with passion, and if it is likewise necessary that 
 there should be something impassive, or all things would perish 
 in time; it is necessary that there should be something prior to
 
 ENNEADES 115 
 
 soul. And, if soul is in the world, but it is necessary there should 
 be something beyond the world, on this account also it is neces- 
 sary that there should be something prior to soul. For if that 
 which is in the world, is in body and matter, nothing would re- 
 main the same [if that which is mundane only existed]. So that 
 man, and all productive principles, would not be perpetual, nor 
 always the same. Hence, that it is necessary intellect should be 
 prior to soul, may be seen from these and many other arguments. 
 
 V. It is necessary, however, to consider intellect truly so 
 called neither as intellect in capacity, nor as proceeding from the 
 privation to the possession of intellect. For if we do not, we 
 must again investigate another intellect prior to this. But we 
 must assume intellect in energy, and eternally. If such an intel- 
 lect, however, has not adventitious thought, whatever it intel- 
 lectually perceives, it perceives from itself. And whatever it 
 possesses, it possesses from itself. But if it perceives intel- 
 lectually by and from itself, it is itself that which it perceives. 
 For if the essence of it were one thing, and the object of its per- 
 ception another, its very essence would not be an intelligible 
 object; and again, it would be intellect in capacity, but not 
 in energy. Neither of these, therefore, must be separated 
 from the other. With us, however, it is usual, from the things 
 with which we are conversant, to separate in our conceptions 
 intellect, and the objects of its perception. . . . 
 
 VI. Let, therefore, intellect be [real] beings, and possess all 
 things in itself, not as in place but as itself, and as being one 
 with them. But all things there subsist together, and neverthe- 
 less are separated from one another. For the soul also which 
 has many notions in itself simultaneously, possesses them with- 
 out any confusion. Each also, when it is requisite, performs 
 what pertains to it, without the co-operation of the rest. And 
 each conception energizes with a purity unmingled with the 
 other inward conceptions. Thus, therefore, and in a still greater 
 degree, intellect is at once all things; and yet, not together, be- 
 cause each real existence is a peculiar power. Every intellect, 
 however, includes all things, in the same manner as genus 
 comprehends species, and as a whole comprehends its parts.
 
 QUINTUS SEPTIMIUS FLORENS 
 TERTULLIANUS 
 
 (160-220) 
 
 A TREATISE ON THE SOUL 
 
 Translated from the Latin* by 
 PETER HOLMES 
 
 CHAPTER IV. THE SOUL CREATED 
 
 AFTER settling the origin of the soul, its condition or state 
 comes up next. For when we acknowledge that the soul orig- 
 inates in the breath of God, it follows that we attribute a be- 
 ginning to it. This Plato, indeed, refuses to assign to it, for he 
 will have the soul to be unborn and unmade. 1 We, however, 
 from the very fact of its having had a beginning, as well as from 
 the nature thereof, teach that it had both birth and creation. 
 And when we ascribe both birth and creation to it, we have 
 made no mistake : for being born, indeed, is one thing, and being 
 made is another, the former being the term which is best 
 suited to living beings. When distinctions, however, have 
 places and times of their own, they occasionally possess also 
 reciprocity of application among themselves. Thus, the being 
 made admits of being taken in the sense of being brought forth; 2 
 inasmuch as everything which receives being or existence, in 
 any way whatever, is in fact generated. For the maker may 
 really be called the parent of the thing that is made: in this 
 sense Plato also uses the phraseology. So far, therefore, as con- 
 
 * From De Anima (about 210). Reprinted from the ANTE-NICENE CHRIS- 
 TIAN LIBRARY, vol. xv, The Writings of Tertullian, translated by Peter Holmes, 
 Edinburgh, 1870, vol. n. 
 
 1 See his Phadrus, c. xxiv. 
 
 z Capit itaque et facturam provenisse poni.
 
 A TREATISE ON THE SOUL 117 
 
 cerns our belief in the souls being made or born, the opinion of 
 the philosopher is overthrown by the authority of prophecy l 
 even: 
 
 CHAPTER V. THE SOUL'S CORPOREAL NATURE 
 
 SUPPOSE one summons a Eubulus to his assistance, and a 
 Critolaus, and a Zenocrates, and on this occasion Plato's friend 
 Aristotle. They may very possibly hold themselves ready for 
 stripping the soul of its corporeity, unless they happen to see 
 other philosophers opposed to them in their purpose and 
 this, too, in greater numbers asserting for the soul a corpo- 
 real nature. Now I am not referring merely to those who mould 
 the soul out of manifest bodily substances, as Hipparchus and 
 Heraclitus [do] out of fire; as Hippon and Thales [do] out of 
 water; as Empedocles and Critias [do] out of blood; as Epicurus 
 [does] out of atoms, since even atoms by their coherence form 
 corporeal masses ; as Critolaus and his Peripatetics [do] out of a 
 certain indescribable quintessence, 2 if that may be called a body 
 which rather includes and embraces bodily substances; but I 
 call on the Stoics also to help me, who, while declaring almost 
 in our own terms that the soul is a spiritual essence (inasmuch 
 as breath and spirit are in their nature very near akin to each 
 other), will yet have no difficulty in persuading [us] that the 
 soul is a corporeal substance. Indeed, Zeno, defining the soul 
 to be a spirit generated with [the body], constructs his argu- 
 ment in this way: That substance which by its departure 
 causes the living being to die is a corporeal one. Now it is by 
 the departure of the spirit, which is generated with [the body], 
 that the living being dies; therefore the spirit which is gener- 
 ated with [the body] is a corporeal substance. But this spirit 
 which is generated with [the body] is the soul : it follows, then, 
 that the soul is a corporeal substance. Cleanthes, too, will have 
 it that family likeness passes from parents to their children not 
 merely in bodily features, but in characteristics of the soul ; as 
 
 1 Or, "inspiration." 
 
 2 Ex quinta nescio qua substantia. Comp. Cicero's Tuscul. 1. 10.
 
 ii8 TERTULLIANUS 
 
 if it were out of a mirror of [a man's] manners, and faculties, 
 and affections, that bodily likeness and unlikeness are caught 
 and reflected by the soul also. It is therefore as being corporeal 
 that it is susceptible of likeness and unlikeness. Again, there is 
 nothing in common between things corporeal and things in- 
 corporeal as to their susceptibility. But the soul certainly sym- 
 pathizes with the body, and shares in its pain, whenever it is 
 injured by bruises, and wounds, and sores: the body, too, 
 suffers with the soul, and is united with it (whenever it is 
 afflicted with anxiety, distress, or love) in the loss of vigour 
 which its companion sustains, whose shame and fear it testifies 
 by its own blushes and paleness. The soul, therefore, is [proved 
 to be] corporeal from this intercommunion of susceptibility. 
 Chrysippus also joins hands in fellowship with Cleanthes, when 
 he lays it down that it is not at all possible for things which are 
 endued with body to be separated from things which have not 
 body; because they have no such relation as mutual contact or 
 coherence. Accordingly Lucretius says: l 
 
 " Tangere enim et tangi nisi corpus nulla potest res." 
 
 " For nothing but body is capable of touching or of being touched." 
 
 [Such severance, however, is quite natural between the soul 
 and the body]; for when the body is deserted by the soul, it is 
 overcome by death. The soul, therefore, is endued with a body; 
 for if it were not corporeal, it could not desert the body. 
 
 CHAPTER X. TEE SOUL'S SIMPLICITY 
 
 IT is essential to a firm faith, to declare with Plato 2 that the 
 soul is simple; in other words, uniform and uncompounded ; 
 simply, that is to say, in respect of its substance. Never mind 
 men's artificial views and theories, and away with the fabri- 
 cations of heresy ! Some maintain that there is within the soul a 
 natural substance the spirit which is different from it: as 
 if to have life the function of the soul were one thing; and 
 
 1 De Nat. Rer. I. 305. 
 
 2 See his Pfuedo, p. 80; Timteus, 12, p. 35 (Bekker, pp. 264, 265).
 
 A TREATISE ON THE SOUL 119 
 
 to emit breath the alleged function of the spirit were 
 another thing. Now it is not in all animals that these two func- 
 tions are found; for there are many which only live, but do not 
 breathe, in that they do not possess the organs of respiration 
 lungs and windpipes. But of what use is it, in an examination 
 of the soul of man, to borrow proofs from a gnat or an ant, 
 when the great Creator in His divine arrangement has allotted 
 to every animal organs of vitality suited to its own disposition 
 and nature, so that we ought not to catch at any conjectures 
 from comparisons of this sort? Man, indeed, although organ- 
 ically furnished with lungs and windpipes, will not on that ac- 
 count be proved to breathe by one process, and to live by an- 
 other; l nor can the ant, although defective in these organs, be 
 on that account said to be without respiration, as if it lived and 
 that was all. . . . 
 
 You think it possible for a thing to live without breath; then 
 why not suppose that a thing might breathe without lungs ? 
 Pray, tell me, what is it to breathe? I suppose it means to 
 emit breath from yourself. What is it not to live? I suppose it 
 means not to emit breath from yourself. This is the answer 
 which I should have to make, if "to breathe" is not the same 
 thing as "to live." It must, however, be characteristic of a 
 dead man not to respire : to respire, therefore, is the characteris- 
 tic of a living man. But to respire is likewise the characteristic 
 of a breathing man : therefore also to breathe is the character- 
 istic of a living man. Now, if both one and the other could pos- 
 sibly have been accomplished without the soul, to breathe 
 might not be a function of the soul, but merely to live. But 
 indeed to live is to breathe, and to breathe is to live. Therefore 
 this entire process, both of breathing and living, belongs to that 
 to which living belongs that is, to the soul. Well, then, since 
 you separate the spirit (or breath) and the soul, separate their 
 operations also. Let both of them accomplish some act apart 
 from one another the soul apart, the spirit apart. Let the 
 soul live without the spirit; let the spirit breathe without the 
 
 1 Aliunde spirabit, aliunde vivet. "In the nature of man, life and breath are 
 inseparable" (Bp. Kaye).
 
 120 TERTULLIANUS 
 
 soul. Let one of them quit men's bodies, let the other remain; 
 let death and life meet and agree. 
 
 If indeed the soul and the spirit are two, they may be divided ; 
 and thus, by the separation of the one which departs from the 
 one which remains, there would accrue the union and meeting 
 together of life and of death. But such a union never will accrue : 
 therefore they are not two, and they cannot be divided; but 
 divided they might have been, if they had been [two]. Still 
 two things may surely coalesce in growth. But the two in 
 question never will coalesce, since to live is one thing, and to 
 breathe is another. Substances are distinguished by their 
 operations. How much firmer ground have you for believing 
 that the soul and the spirit are but one, since you assign to 
 them no difference; so that the soul is itself the spirit, respira- 
 tion being the function of that of which life also is! But what 
 if you insist on supposing that the day is one thing, and the 
 light, which is incidental to the day, is another thing, whereas 
 day is only the light itself ? There must, of course, be also 
 different kinds of light, as [appears] from the ministry of fires. 
 So likewise will there be different sorts of spirits, according as 
 they emanate from God or from the devil. Whenever, indeed, 
 the question is about soul and spirit, the soul will be [under- 
 stood to be] itself the spirit, just as the day is the light itself. 
 For a thing is itself identical with that by means of which itself 
 exists. 
 
 CHAPTER XII. THE MIND AND SOUL 
 
 IN like manner the mind also, or animus, which the Greeks 
 designate NOY2, is taken by us in no other sense than as 
 indicating that faculty or apparatus which is inherent and 
 implanted in the soul, and naturally proper to it, whereby it 
 acts, whereby it acquires knowledge, and by the possession of 
 which it is capable of a spontaneity of motion within itself, 
 and of thus appearing to be impelled by the mind, as if it were 
 another substance., as is maintained by those who determine 
 the soul to be the moving principle of the universe l the god 
 
 1 Comp. The Apology, c. xlviii.; August. De Civ. Dei, xiii. 17.
 
 A TREATISE ON THE SOUL 121 
 
 of Socrates, Valentinus ' "only-begotten" of his father 1 Bylhus, 
 and his mother Sige. How confused is the opinion of Anaxa- 
 goras! For, having imagined the mind to be the initiating 
 principle of all things, and suspending on its axis the balance 
 of the universe; affirming, moreover, that the mind is a simple 
 principle, unmixed, and incapable of admixture, he mainly on 
 this very consideration separates it from all amalgamation with 
 the soul; and yet in another passage he actually incorporates 
 it with the soul. This [inconsistency] Aristotle has also ob- 
 served; but whether he meant his criticism to be constructive, 
 and to fill up a system of his own, rather than destructive of the 
 principles of others, I am hardly able to decide. As for himself, 
 indeed, although he postpones his definition of the mind, yet he 
 begins by mentioning, as one of the two natural constituents of 
 the mind, that divine principle which he conjectures to be im- 
 passible, or incapable of emotion, and thereby removes from 
 all association with the soul. For whereas it is evident that the 
 soul is susceptible of those emotions which it falls to it naturally 
 to suffer, it must needs suffer either by the mind or with the 
 mind. Now if the soul is by nature associated with the mind, 
 it is impossible to draw the conclusion that the mind is im- 
 passible; or again, if the soul suffers not either by the mind or 
 with the mind, it cannot possibly have a natural association 
 with the mind, with which it suffers nothing, and which suffers 
 nothing itself. Moreover, if the soul suffers nothing by the 
 mind and with the mind, it will experience no sensation, nor 
 will it acquire any knowledge, nor will it undergo any emotion 
 through the agency of the mind, as they maintain it will. For 
 Aristotle makes even the senses passions, or states of emotion. 
 And rightly too. For to exercise the senses is to suffer emotion, 
 because to suffer is to feel. In like manner, to acquire know- 
 ledge is to exercise the senses, and to undergo emotion is to 
 exercise the senses ; and the whole of this is a state of suffering. 
 But we see that the soul experiences nothing of these things, in 
 such a manner as that the mind also is not affected by the emo- 
 tion, by which, indeed, and with which, all is effected. It fol- 
 
 1 Comp. Adv. Valentin, vii.
 
 122 TERTULLIANUS 
 
 lows, therefore, that the mind is capable of admixture, in oppo- 
 sition to Anaxagoras; and passible or susceptible of emotion, 
 contrary to the opinion of Aristotle. 
 
 Besides, if a separate condition between the soul and mind is 
 to be admitted, so that they be two things in substance, then 
 of one of them, emotion and sensation, and every sort of taste, 
 and all action and motion, will be the characteristics; whilst of 
 the other the natural condition will be calm, and repose, and 
 stupor. There is therefore no alternative: either the mind must 
 be useless and void, or the soul. But if these affections may cer- 
 tainly be all of them ascribed to both, then in that case the two 
 will be one and the same, and Democritus will carry his point 
 when he suppresses all distinction between the two. The ques- 
 tion will arise how two can be one whether by the confusion 
 of two substances, or by the disposition of one? We, however, 
 affirm that the mind coalesces with the soul, not indeed as 
 being distinct from it in substance, but as being its natural 
 function and agent. 
 
 CHAPTER XVI. TEE SOUL'S RATIONAL AND 
 IRRATIONAL PARTS 
 
 THAT position of Plato's is also quite in keeping with the 
 faith, in which he divides the soul into two parts the rational 
 and the irrational. To this definition we take no exception, 
 except that we would not ascribe this twofold distinction to the 
 nature [of the soul]. It is the rational element which we must 
 believe to be its natural condition, impressed upon it from its 
 very first creation by its Author, who is Himself essentially 
 rational. For how should that be other than rational, which 
 God produced on His own prompting; nay more, which He 
 expressly sent forth by His own afflatus or breath? The irra- 
 tional element, however, we must understand to have accrued 
 later, as having proceeded from the instigation of the serpent 
 the very achievement of [the first] transgression which 
 thenceforward became inherent in the soul, and grew with its 
 growth, assuming the manner by this time of a natural develop-
 
 A TREATISE ON THE SOUL 123 
 
 ment, happening as it did immediately at the beginning of na- 
 ture. But, inasmuch as the same Plato speaks of the rational 
 element only as existing in the soul of God Himself, if we were 
 to ascribe the irrational element likewise to the nature which 
 our soul has received from God, then the irrational element will 
 be equally derived from God, as being a natural production, 
 because God is the author of nature. Now from the devil pro- 
 ceeds the incentive to sin. All sin, however, is irrational: 
 therefore the irrational proceeds from the devil, from whom sin 
 proceeds; and it is extraneous to God, to whom also the irra- 
 tional is an alien principle. The diversity, then, between these 
 two elements arises from the difference of their authors. When, 
 therefore, Plato reserves the rational element [of the soul] to 
 God alone, and subdivides it into two departments the 
 irascible, which they call Ovpiicdv, and the concupiscible, which 
 they designate by the term i-mQv^TiKov (in such a way as to 
 make the first common to us and lions, and the second shared 
 between ourselves and flies, whilst the rational element is con- 
 fined to us and God). . . . 
 
 CHAPTER XXII. RECAPITULATION 
 
 HERMOGENES has already heard from us what are the other 
 natural faculties of the soul, as well as their vindication and 
 proof; whence it may be seen that the soul is rather the offspring 
 of God than of matter. The names of these faculties shall here, 
 be simply repeated, that they may not seem to be forgotten 
 and passed out of sight. We have assigned, then, to the soul 
 both that freedom of the will which we just now mentioned, 
 and its dominion over the works of nature, and its occasional 
 gift of divination, independently of that endowment of pro- 
 phecy which accrues to it expressly from the grace of God. We 
 shall therefore now quit this subject of the soul's disposition, 
 in order to set out fully in order its various qualities. The soul, 
 then, we define to be sprung from the breath of God, immortal, 
 possessing body, having form, simple in its substance, intelli- 
 gent in its own nature, developing its powers in various ways,
 
 124 TERTULLIANUS 
 
 free in its determinations, subject to the changes of accident, 
 in its faculties mutable, rational, supreme, endued with an in- 
 stinct of presentiment, evolved out of one [archetypal soul]. 
 It remains for us now to consider how it is developed out of this 
 one original source; in other words, whence, and when, and how 
 it is produced.
 
 GREGORY OF NYSSA 
 (331-394) 
 
 THE ENDOWMENT OF MAN 
 
 Translated from the Greek * by 
 BENJAMIN RAND 
 
 CHAPTER XII. TEE LOCATION OF TEE INTELLECT 
 
 DISMISS therefore every idle fancy and foolish conjecture of 
 those who confine the intellectual activity to particular loca- 
 tions in the body. Some of them think the heart is the seat of 
 the guiding principle of the soul ; others of them say the mind 
 dwells in the brain. And these views they seek to maintain 
 upon certain superficial grounds of probability. Those who 
 give precedence to the heart regard its location as a proof of 
 their affirmation, inasmuch as it occupies to all appearance the 
 central place of the entire body. For this reason any exercise 
 of the will can easily be transmitted from the centre throughout 
 the whole body, and can thus proceed into action. As addi- 
 tional evidence they cite the emotions of pain and of anger in 
 men, since these passions appear in a manner to bring every 
 part into sympathy. The others, who attribute to the brain the 
 faculty of thought, say that nature has constructed the brain 
 as a citadel for the entire body, and the mind reigns therein like 
 a king, with the organs of sense like messengers and armour- 
 bearers standing guard about it. They assert as a convincing 
 proof of their contention that with those who have suffered any 
 lesion of the membrane of the brain an unbalancing and de- 
 rangement of the faculty of thought commonly occurs, and 
 
 * From Gregory of Nyssa's Hep? Karao-Ktu^s dvOp^vov in his Opera, Gr. et 
 Lat. Paris, 1615; 2 ed. 1638.
 
 126 GREGORY OF NYSSA 
 
 that those whose brains are clogged by drunkenness lose all 
 consciousness of what is fitting. 
 
 Both parties who accept these views supplement their pre- 
 sumptions concerning the ruling faculty of the soul by reasons 
 more closely derived from nature. One party says that the 
 activity of the intellect has a kinship with the igneous, be- 
 cause both fire and the intellect are in constant motion. Since 
 now they allow that heat has its source in the organ of the 
 heart, they affirm that the activity of the mind is blended with 
 the mobility of the heat, and as a consequence that the heart, 
 which contains the heat, is the repository of the intellectual 
 nature. The other party contend, on the contrary, that the 
 membrane of the brain (as the skin-like cover enveloping the 
 brain is called) is, as it were, the foundation and root of the 
 organs of sense. Their warrant for the truth of this affirmation 
 is because the activity of the perceptive faculty can never be 
 located otherwise, than in this part where both the ear is at- 
 tached and receives the sounds that fall upon it; where also the 
 sight, inseparably connected with the base of the eyes, trans- 
 mits the images that strike the pupils and makes an impression 
 of them within; where also the different kinds of scent are dis- 
 criminated through the sniffing of the organs of smell ; and where 
 also the sensation of taste is determined by the testing power of 
 the membrane of the brain, which sends out certain fibrous 
 runners bearing sensation, and proceeding through the verte- 
 brae of the neck into the filterlike passage to the muscles there. 
 
 I concede that the intellectual processes of the soul are often 
 disturbed by overpowering diseases, that the natural activity 
 of the understanding is blunted by a bodily cause, and that the 
 heart is a source of bodily fire and becomes aroused to emo- 
 tional impulses. I admit further also that the membrane of the 
 brain serves as a foundation of the organs of sense, as those 
 affirm who make such investigations, since it envelops the brain 
 and is moistened there by the discharging vapour. I have 
 learned this from those who have made anatomical studies, and 
 have no reason to doubt the truth of what is alleged. Never- 
 v theless I derive therefrom no proof whatever, that the incorpo-
 
 THE ENDOWMENT OF MAN 127 
 
 real nature is confined by certain local barriers. We know, how- 
 ever, that disturbances of the intellect do not originate from 
 the mere clogging of the brain by drunkenness, but rather, as 
 the physicians affirm, if the skin enveloping the sides be- 
 comes diseased, the intellect likewise assumes a disordered con- 
 dition. This disease they call phrenitis, since the name of that 
 skin is phrenes. The theory of joint-sensation occasioned by 
 a pain in the heart is also mistaken. When not the heart in- 
 deed but the orifice of the stomach is painfully irritated they 
 ignorantly attribute the suffering to the heart. Those who 
 have made a careful study of diseases explain this as due to 
 the fact that in a painful condition of the whole body there 
 occurs a closing of the ducts, and as a result everything hin- 
 dered in evaporation is driven back into the depths of the 
 hollow parts of the body. In consequence, therefore, of the 
 compression of the organs of respiration occasioned by the 
 environment, a more powerful respiration takes place through 
 the nature (i.e. of the body), as it seeks to remove the pressure 
 for the purpose of the expansion of the contracted parts. This 
 distress in breathing we regard as a symptom of pain, and call 
 it sighing and groaning. But the pressure also that we imagine 
 is felt in the region of the heart, is occasioned by unpleasant 
 sensations not of the heart, but of the orifice of the stomach, 
 and is due to the same cause, usually the contraction of the 
 ducts, since indeed the gall-bladder as a result of the com- 
 pression sends forth its sharp and smarting bile into the 
 orifice of the stomach. An evidence of this is the yellow ap- 
 pearance of persons suffering from such disease as jaundice, due 
 to the powerful contraction of the gall, which causes its juice to 
 flow into the veins. 
 
 But the opposite emotion also, that of joy or laughter, affords 
 our position still stronger support. If one is gladdened by a 
 pleasant communication the ducts of the body will also be 
 enlarged owing to the pleasure. Now in the case of pain the 
 fine and invisible evaporations of the ducts are checked, and 
 as the viscera within is bound in tighter position, the moist va- 
 pour is forced to the head, and to the membrane of the brain.
 
 128 GREGORY OF NYSSA 
 
 This vapour being accumulated in the hollows of the brain is 
 then pressed out through the ducts lying beneath to the eyes, 
 where the contraction of the eyelashes segregates the moisture 
 in the form of drops called tears. Likewise, on the other hand, 
 it must be observed that if the ducts are enlarged beyond their 
 accustomed size in consequence of the opposite affections, a 
 quantity of air is drawn through them toward the depths, and 
 is there again naturally expelled through the mouth, since the 
 entire viscera, and especially it is said the liver, forcefully ejects 
 this air by a convulsive and violent movement. Nature there- 
 fore provides for the passage of this air through an enlargement 
 of the aperture of the mouth by means of the pushing apart of 
 the cheeks enclosing the air. This condition is termed laughter. 
 Thus neither on account of the alleged reason can the intel- 
 lectual faculty be attributed preferably to the liver; nor on 
 account of the agitation of the blood of the heart in agreeable 
 emotion can the location of the faculty of thought be sup- 
 posed in the heart. These phenomena must therefore be re- 
 ferred to some special organization of the body, and it must be 
 believed that the mind through some inexplicable plan of 
 blending is distributed in all parts of the body, relatively to their 
 importance. 
 
 If on the other hand one should oppose to us, that Holy 
 Writ (Psalm vm, 6) attributes to the heart most important 
 psychical activities, we cannot consent to such affirmation 
 without a closer examination. For he who makes mention of 
 the heart includes therewith the reins, saying God "who 
 trieth the heart and reins," so that one must apply the seat 
 of thought to both, or to neither of the two. But though one 
 proves to me that the powers of the intellect are blunted in 
 certain conditions of the body, or are even forced completely 
 into inaction, I do not consider this fact sufficient evidence, that 
 the power of thought is limited to any one locality in such wise 
 that it would be driven from its accustomed place of sojourn 
 owing to inflammation befalling the parts. For it is a truth ap- 
 plicable to all bodily things, that if a vessel is already occupied 
 by anything which fills it, nothing else can find therein a place.
 
 THE ENDOWMENT OF MAN 129 
 
 For the intellectual nature neither takes possession of the empty 
 parts of the body, nor permits itself to be expelled by any 
 superabundant flesh ; but the entire body is similar in its organi- 
 sation to a wind instrument, which a musician oftentimes 
 knows how to play, but cannot show his knowledge because the 
 uselessness of the instrument prevents the display of his art. 
 Either it is unfit owing to age, or cracked from a fall, or 
 unusable on account of rust or mould. As a result it is mute and 
 ineffective, even if played upon by the most expert master of 
 the pipes. Even so the mind pervades the entire organism, 
 and acting in harmony with the powers of thought, as it 
 naturally can, operates upon each one of the individual parts. 
 In the case of those that are in their natural condition it pro- 
 duces the customary effect, but in bodies which are too weak 
 to receive the operation of its art, it remains inactive and 
 inefficacious. For it is the peculiar quality of the mind that it 
 maintains friendly relationship with that which is in its natural 
 conditions, but is alienated from whatever has receded from 
 nature. 
 
 At this stage a principle suggests itself to me, which is based 
 even more upon the natural inner consideration of things, and 
 from which we can derive still higher precepts. For the divine 
 nature is itself the most beautiful of all things that is pre- 
 eminently good; and the essence towards which anything 
 which possesses the desire for the beautiful is drawn. We, there- 
 fore, affirm that the mind, precisely because it is created after 
 the image of the most beautiful, can itself abide in the beautiful 
 so long as it possesses the amount of similarity with its proto- 
 type that it receives ; and that on the contrary if it recedes in 
 any measure from this resemblance, it is deprived of that 
 beauty in which it was resident. But just as we said the mind 
 possesses in itself beauty from similarity with its prototype, 
 and like a mirror profits by the image of the form appearing in 
 it; so in a similar manner we reason that nature also stands 
 subject to the guidance and ruling of reason, and profits by its 
 beauty and perfection. It is, as it were, a mirror of a mirror, and 
 the material of our personality in which our nature is observed,
 
 i 3 o GREGORY OF NYSSA 
 
 is governed, and held together by reason. So long as the one 
 cleaves to the other the community also of true beauty and 
 perfection pervades in right relation all the parts, and transfers 
 the lustre of divine grandeur to that connected with it. On the 
 other hand, if a sundering of this incorporation with the good 
 occurs, or if the higher appears in a subordinate relation to the 
 lower, then also the unloveliness of the material abundance by 
 nature reveals itself, (for matter is in itself something unformed 
 and crude). Thus owing to this formlessness, that beauty of 
 nature which adorns it through reason is also destroyed. 
 Hence the unloveliness of matter passes over through nature 
 to the mind itself, in such a manner that the image of God is 
 seen no longer in the impression on the features. For the mind 
 now receives the picture of the (divine) perfections as upon 
 the back of the mirror, and although it reflects the rays of the 
 splendour reflected from the good, it also rubs off the form- 
 lessness of matter upon itself. Thus evil originates, the ex- 
 istence of which commences with the deprivation of the good. 
 But the beautiful is everything that stands in harmonious rela- 
 tions with the original good; but everything that stands out- 
 side of this relation, and of similarity with it, has no part in the 
 beautiful. If now according to the reasoning we have 
 observed there is only one original good, and if the mind in 
 virtue of its creation in the image of the beautiful has itself 
 beauty, and if the nature comprised by the mind is as it were 
 an image of an image, then it is thereby proved that our 
 material principle has persistence and continued support just 
 as long as it is guided and kept in order by nature, but that it is 
 committed to dissolution and decay if it forsakes that which 
 gives it support and persistence, and is torn from its incorpora- 
 tion with the beautiful. But this does take place precisely when 
 there has been a reversion from nature towards the opposite. 
 For there is every necessity that matter robbed of its own form 
 must likewise suffer an alteration corresponding to this shape- 
 lessness and unloveliness. 
 
 This is nevertheless an incidental explanation which has 
 developed from our discussion upon the principal topic at
 
 THE ENDOWMENT OF MAN 131 
 
 issue. The chief question was, whether the intellect has its 
 location in one special part of us, or whether it pervades all 
 parts alike. For the reasoning of those who circumscribe the 
 mind with local parts, and cite as a proof of their assumption 
 the fact that if the membrane of the brain is in an unnatural 
 condition thought is impaired, has disclosed that the power of 
 the soul is in every part of the human organism that is in a 
 condition to receive its activity, and similarly becomes inactive 
 so soon as any part loses its natural condition. For that reason 
 there was necessarily involved in the argument, the proposal by 
 which we learn that in the human organism the mind is regu- 
 lated by God, and through that in turn the material life is 
 guided so long as it remains in the service of nature, but that 
 if it turns aside from nature it also loses the power of activity, 
 derived from the mind. Thus we return again to our point of 
 departure, to wit, that the mind exercises power in such parts 
 of the body as have not lost their natural constitution as a 
 result of disease, and remains effective if they continue in con- 
 formity to nature, but on the contrary is powerless in those 
 parts which are incapable of maintaining its activity.
 
 SAINT AUGUSTINE 
 
 (354-430) 
 
 ON THE TRINITY 
 
 Translated from the Latin * by 
 ARTHUR WEST HADDAN 
 
 BOOK X. CHAPTER X. THE NATURE OF MIND 
 
 13. LET it not then add anything to that which it knows 
 itself to be, when it is bidden to know itself. For it knows, at 
 any rate, that this is said to itself; namely, to itself, that is, and 
 that lives, and that understands. But a dead body also is, and 
 cattle live; but neither a dead body nor cattle understand. 
 Therefore it so knows that it so is, and that it so lives, as an 
 understanding is and lives. When, therefore, for example's 
 sake, the mind thinks itself air, it thinks that air understands; 
 it knows,however, that itself understands, but it does not know 
 itself to be air, but only thinks so. Let it separate that which 
 it thinks itself; let it discern that which it knows; let this re- 
 main to it, about which not even have they doubted who have 
 thought the mind to be this corporeal thing or that. For cer- 
 tainly every mind does not consider itself to be air; but some 
 think themselves fire, others the brain, and some one kind of 
 corporeal thing, others another, as I have mentioned before; 
 yet all know that they themselves understand, and are, and 
 live; but they refer understanding to that which they under- 
 stand, but to be, and to live, to themselves. And no one doubts, 
 either that no one understands who does not live, or that no one 
 lives of whom it is not true that he is; and that therefore by 
 consequence that which understands both is and lives; not as a 
 
 * From De Trinitale, Strasburg, 1477. Reprinted from Augustine's On the 
 Trinity, translated by Arthur West Haddan, Edinburgh, 1873.
 
 ON THE TRINITY 133 
 
 dead body is which does not live, nor as a soul lives which does 
 not understand, but in some proper and more excellent manner. 
 Further, they know that they will, and they equally know that 
 no one can will who is not and who does not live; and they also 
 refer that will itself to something which they will with that will. 
 They know also that they remember; and they know at the 
 same time that nobody could remember, unless he both was and 
 lived; but we refer memory itself also to something, in that we 
 remember those things. Therefore the knowledge and science 
 of many things are contained in two of these three, memory 
 and understanding; but will must be present, that we may en- 
 joy or use them. For we enjoy things known, in which things 
 themselves the will finds delight for their own sake, and so re- 
 poses; but we use those things, which we refer to some other 
 thing which we are to enjoy. Neither is the life of man vicious 
 and culpable in any other way, than as wrongly using and 
 wrongly enjoying. But it is no place here to discuss this. 
 
 14. But since we treat of the nature of the mind, let us 
 remove from our consideration all knowledge which is received 
 from without, through the senses of the body; and attend more 
 carefully to the position which we have laid down, that all 
 minds know and are certain concerning themselves. For men 
 certainly have doubted whether the power of living, of remem- 
 bering, of understanding, of willing, of thinking, of knowing, of 
 judging, be of air, or of fire, or of the brain, or of the blood, or 
 of atoms, or besides the usual four elements of a fifth kind of 
 body, I know not what; or whether the combining or temper- 
 ing together of this our flesh itself has power to accomplish 
 these things. And one has attempted to establish this, and 
 another to establish that. Yet who ever doubts that he him- 
 self lives, and remembers, and understands, and wills, and 
 thinks, and knows, and judges? Seeing that even if he doubts, 
 he lives; if he doubts, he remembers why he doubts; if he 
 doubts, he understands that he doubts; if he doubts, he wishes 
 to be certain; if he doubts, he thinks; if he doubts, he knows 
 that he does not know; if he doubts, he judges that he ought not 
 to assent rashly. Whosoever therefore doubts about anything
 
 134 SAINT AUGUSTINE 
 
 else, ought not to doubt of all these things; which if they were 
 not, he would not be able to doubt of anything. 
 
 15. They who think the mind to be either a body or the 
 combination or tempering of the body, will have all these things 
 to seem to be in a subject, so that the substance is air, or fire, or 
 some other corporeal thing, which they think to be the mind; 
 but that the understanding is in this corporeal thing as its 
 quality, so that this coporeal thing is the subject, but the 
 understanding is in the subject, viz. that the mind is the sub- 
 ject, which they rule to be a corporeal thing, but the under- 
 standing, or any other of those things which we have mentioned 
 as certain to us, is in that subject. They also hold nearly the 
 same opinion who deny the mind itself to be body, but think it 
 to be the combination or tempering together of the body; for 
 there is this difference, that the former say that the mind itself 
 is the substance, in which the understanding is, as in a subject; 
 but the latter say that the mind itself is in a subject, viz. in the 
 body, of which it is the combination or tempering together. 
 And hence, by consequence, what else can they think, except 
 that the understanding also is in the same body as in a subject? 
 
 16. And all these do not perceive that the mind knows itself, 
 even when it seeks for itself, as we have already shown. But 
 nothing is at all rightly said to be known while its substance is 
 not known. And therefore, when the mind knows itself, it 
 knows its own substance; and when it is certain about itself, 
 it is certain about its own substance. But it is certain about 
 itself, as those things which are said above prove convincingly ; 
 although it is not at all certain whether itself is air, or fire, or 
 some body, or some function of body. Therefore it is not any 
 of these. And that whole which is bidden to know itself, belongs 
 to this, that it is certain that it is not any of those things of 
 which it is uncertain, and is certain that it is that only, which 
 only it is certain that it is. For it thinks in this way of fire, 
 or air, and whatever else of the body it thinks of. Neither 
 can it in any way be brought to pass that it should so think 
 that which itself is, as it thinks that which itself is not. Since 
 it^thinks all these things through an imaginary phantasy,
 
 ON THE TRINITY 135 
 
 whether fire, or air, or this or that body, or that part or com- 
 bination and tempering together of the body : nor assuredly is 
 it said to be all those things, but some one of them. But if 
 it were any one of them, it would think this one in a different 
 manner from the rest, viz. not through an imaginary phantasy, 
 as absent things are thought, which either themselves or some of 
 like kind have been touched by the bodily sense; but by some 
 inward, not feigned, but true presence (for nothing is more 
 present to it than itself) ; just as it thinks that itself lives, and 
 remembers, and understands, and wills. For it knows these 
 things in itself, and does not imagine them as though it had 
 touched them by the sense outside itself, as corporeal things are 
 touched. And if it attaches nothing to itself from the thought 
 of these things, so as to think itself to be something of the kind, 
 then whatsoever remains to it from itself, that alone is itself. 
 
 CHAPTER XL MEMORY, UNDERSTANDING, 
 AND WILL 
 
 17. PUTTING aside, then, for a little while all other things, of 
 which the mind is certain concerning itself, let us especially 
 consider and discuss these three memory, understanding, 
 will. For we may commonly discern in these three the charac- 
 ter of the abilities of the young also; since the more tenaciously 
 and easily a boy remembers, and the more acutely he under- 
 stands, and the more ardently he studies, the more praise- 
 worthy is he in point of ability. But when the question is about 
 any one's learning, then we ask not how solidly and easily he 
 remembers, or how shrewdly he understands; but what it is 
 that he remembers, and what it is that he understands. And 
 because the mind is regarded as praiseworthy, not only as being 
 learned, but also as being good, one gives heed not only to 
 what he remembers and what he understands, but also to what 
 he wishes; not how ardently he wishes, but first what it is he 
 wishes, and then how greatly he wishes it. For the mind that 
 loves eagerly is then to be praised, when it loves that which 
 ought to be loved eagerly. Since, then, we speak of these three
 
 136 SAINT AUGUSTINE 
 
 ability, knowledge, use the first of these is to be considered 
 under the three heads, of what a man can do in memory, and 
 understanding, and will. The second of them is to be consid- 
 ered in regard to that which any one has in his memory and in 
 his understanding, whither he has attained by a studious will. 
 But the third, viz. use, lies in the will, which handles those 
 things that are contained in the memory and understanding, 
 whether it refer them to anything further, or rest satisfied with 
 them as an end. For to use, is to take up something into the 
 power of the will ; and to enjoy, is to use with joy, not any longer 
 of hope, but of the actual thing. Accordingly, every one who 
 enjoys, uses; for he takes up something into the power of the 
 will, wherein he also is satisfied as with an end. But not every 
 one who uses, enjoys, if he has sought after that, which he takes 
 up into the power of the will, not on account of the thing itself, 
 but on account of something else. 
 
 18. Since, then, these three, memory, understanding, will, 
 are not three lives, but one life; nor three minds, but one mind; 
 it follows certainly that neither are they three substances, but 
 one substance. Since memory, which is called life, and mind, 
 and substance, is so called in respect to itself; but it is called 
 memory, relatively to something. And I should say the same 
 also of understanding and of will, since they are called under- 
 standing and will relatively to something; but each in respect 
 to itself is life, and mind, and essence. And hence these three 
 are one, in that they are one life, one mind, one essence; and 
 whatever else they are severally called in respect to themselves, 
 they are called also together, not plurally, but in the singular 
 number. But they are three, in that wherein they are mutually 
 referred to each other; and if they were not equal, and this not 
 only each to each, but also each to all, they certainly could not 
 mutually contain each other; for not only is each contained by 
 each, but also all by each. For I remember that I have mem- 
 ory, and understanding, and will; and I understand that I 
 understand, and will, and remember; and I will that I will, and 
 remember, and understand; and I remember together my whole 
 memory, and understanding, and will. For that of my memory
 
 ON THE TRINITY 137 
 
 which I do not remember, is not in my memory; and nothing is 
 so much in the memory as memory itself. Therefore I remem- 
 ber the whole memory. Also, whatever I understand I know 
 that I understand, and I know that I will whatever I will; but 
 whatever I know I remember. Therefore I remember the whole 
 of my understanding, and the whole of my will. Likewise, when 
 I understand these three things, I understand them together as 
 whole. For there is none of things intelligible which I do not 
 understand, except what I do not know; but what I do not 
 know, I neither remember, nor will. Therefore, whatever of 
 things intelligible I do not understand, it follows also that I 
 neither remember nor will. And whatever of things intelligible 
 I remember and will, it follows that I understand. My will also 
 embraces my whole understanding and my whole memory, 
 whilst I use the whole that I understand and remember. And, 
 therefore, while all are mutually comprehended by each, and as 
 wholes, each as a whole is equal to each as a whole, and each as 
 a whole at the same time to all as wholes ; and these three are 
 one, one life, one mind, one essence.
 
 THOMAS AQUINAS 
 
 (1225-1274) 
 
 SUMMA THEOLOGICA 
 
 Translated from the Latin* by 
 BENJAMIN RAND 
 
 QUESTION LXXVI. RATIONALITY THE ESSENTIAL 
 FORM IN MAN 
 
 Article j. Are there besides the Rational Soul in Man, other Souls 
 different in Essence ? 
 
 (a) IT would appear that beside the rational soul in man 
 other souls essentially different exist, to wit, the sensitive and 
 nutritive. 
 
 I. For what is perishable does not belong to the same sub- 
 stance as what is imperishable. But the rational soul is imper- 
 ishable, whereas the other souls, that is, the nutritive and the 
 sensitive, are perishable. It is not possible, therefore, that there 
 is in man a single essence of a rational, sensitive, and nutritive 
 soul. 
 
 II. If it be said that the sensitive soul of man is imperishable 
 there is opposed to such a view, the declaration of Aristotle 
 (10 Metaph.), that what is perishable differs in kind from that 
 which is imperishable. But the sensitive soul in the horse, 
 lion, and other animals is perishable. If therefore it were 
 imperishable in man, then the sensitive soul in man and brute 
 would not be of the same kind. Nevertheless that is called 
 animal which has a sensitive soul. Animal would therefore not 
 be the common genus for man and the other animals. But this 
 is incongruous. 
 
 * Freely translated from Thomas Aquinas' Summa Theologica, Basil, 1485; 
 in his Opera Omnia, Romae, 1889, vol. v.
 
 SUMMA THEOLOGICA 139 
 
 III. Aristotle says "the embryo is first animal, and then 
 man" (2 de Gener, c. 3). But this would not be possible if the 
 sensitive soul had the same essence as the rational. For the 
 animal is thus designated because of its sensitive soul; and 
 man is so called because of his rational soul. Consequently there 
 is in man no single essence composed of a sensitive and a ra- 
 tional soul. 
 
 IV. Aristotle says (8 Metapk.) " the genus of being is derived 
 from the matter, but the difference from the essential form." 
 Now rationality which is the specific difference in man is 
 derived from the rational soul; but the animal is so called 
 because it has a body animated by a sensitive soul. The ra- 
 tional soul, therefore, is related to the body animated by the 
 sensitive soul, as form is to matter. The rational soul is not, 
 therefore, identical in essence with the sensitive soul in man, 
 but presupposes the latter as its substrate matter. 
 
 But on the other hand it should be said: we do not admit two 
 souls in one and the same man, as Jacobus and the other Syri- 
 ans affirm, to wit, an animal *soul which animates the body, 
 and is mixed with the blood, and a rational soul which ministers 
 to the reason; but there is a single soul in man which animates 
 the body by its presence, and orders by its own principle of 
 reason" (lib. de eccl. dogm. c. 15). 
 
 (b) I reply that Plato postulated (Timaus) in one body dif- 
 ferent souls, distinguished likewise by their organs, to which he 
 attributed diverse vital functions, declaring that there is a 
 nutritive faculty in the liver, an appetitive faculty in the heart, 
 and a rational faculty in the brain. 
 
 Aristotle refutes (2 deAnima, c. 2) this view so far as it con- 
 cerns those powers of the soul which in their activities employ 
 bodily organs. His reason is that in case of those animals which 
 though cut in two still live, the different operations of the soul 
 in any one part are still found, such as feeling and desire. But 
 this would not be the case if diverse principles of psychical 
 activities, differing essentially from one another, were ascribed 
 to the different parts of the body. But with regard to the 
 rational soul he appears to have left it an open question,
 
 140 THOMAS AQUINAS 
 
 whether it is separated from the other powers of the soul only 
 by virtue of reason, or also in location. 
 
 The opinion of Plato would indeed be justified, if one sup- 
 posed the soul were united to the body not as form, but as 
 moving principle, as Plato assumed. For in that case no- 
 thing incongruous results, if the same mobile object be moved 
 by different moving forces, especially in its different sub- 
 ordinate parts. 
 
 But if we assume that the soul is united to the body as its 
 form, it is then wholly impossible that several souls, differing 
 essentially from one another, should have existence in a single 
 body. This can be clearly shown in three ways. 
 
 1. The animal would not have unity of being in which there 
 were several souls. Nothing has simple unity, save through 
 form alone, by which a thing has its being. For from the same 
 form that a thing derives entity, it derives unity; and therefore 
 what are designated by different forms are not singly one, as 
 for instance a white man. If therefore man were a living being 
 by virtue of some one form, that'is the vegetative soul; animal 
 by virtue of another form, the sensitive soul; and were a think- 
 ing being by virtue of another form, the rational soul, he would 
 not then be singly one. Thus Aristotle also argues (8 Metaph.}, 
 as against Plato, that if there were one idea of an animal, and 
 another of a biped, there would be no single entity of a biped 
 animal. Accordingly he asks (i deAnima), in answer to those 
 who assume different souls in the same body, what then holds 
 together these diverse souls, that is, what makes a unity of 
 them. It is not possible to say that they are made indeed into 
 a unity through the body; for the soul contains the body and 
 makes it to be one, rather than the reverse. 
 
 2. This appears impossible by the mode of predication. For 
 the attributes which embody different forms in the same thing 
 are predicable of one another, either accidentally, or reciprocally. 
 If these forms have no relation to one another, as if one were to 
 say that what is white may also be sweet, then the attribute 
 does not depend on the substance itself, but arises from other 
 causes, since it is not in the essence of white to be sweet. Or, if
 
 SUMMA THEOLOGICA 141 
 
 the attributes are naturally related they will be predicated 
 per se, according to the second definition of per se, because the 
 subject then appears in the definition of the predicate. Thus I 
 can say, the surface must precede the colour, if the surface of the 
 body is coloured, for the existence of a surface must precede the 
 concept of colour. Man is therefore owing to certain forms said 
 to be ananimal, and to other forms a man. The affirmation ' man 
 is an animal,' therefore, must be either purely 'accidental,' 
 or, one of the souls must precede the other. But the former 
 statement is manifestly false, because animal is predicated of 
 man per se, and not per accidens; and the latter is untrue, be- 
 cause man is not contained in the definition of animal, but the 
 reverse. It therefore follows, that there can only be one and the 
 same form from which it results, both that man is animal, and 
 that he is also man. If it were otherwise man would not be 
 what is designated by animal, since the necessary attribute for 
 animal would be predicated only accidentally of man. 
 
 3. Again this appears impossible because of the fact, that one 
 activity of the soul inhibits another, if it be very intense. This 
 would by no means happen unless the principle of action in 
 man were in essence one. It follows, therefore, that there is only 
 one soul as to number in man, which must be deemed at the 
 same time nutritive, sensitive, and rational. 
 
 How this can happen may easily be understood by anyone 
 who pays heed to the differences of species and of forms. For 
 the forms and species of things differ from one another, in that 
 one is more or less perfect than another. Thus plants are more 
 perfect than inanimate objects; animals again rank above 
 plants; and man in turn rises above the beasts. And among the 
 individuals of the same class there are also varying degrees of 
 perfection. For this reason Aristotle compares (8 Mela ph.) the 
 forms of species to numbers, which differ in type according as a 
 unit is added or subtracted. And he compares (2 de Anima) the 
 different souls to figures in which one contains another, and yet 
 exceeds it. In like manner the rational soul contains within its 
 powers, both what belongs to the sensitive soul of the brutes, and 
 likewise to the nutritive soul of the plant. The surface, therefore,
 
 142 THOMAS AQUINAS 
 
 which has the figure of a pentagon, also is not by one figure in it 
 a square, and by another a pentagon ; for in that case the square 
 would be superfluous, since it is contained in the pentagon. 
 Thus Socrates also is not by virtue of one soul a man, and by 
 virtue of another an animal ; but he is both, through one and the 
 same soul. 
 
 (c) I. The sensitive soul is imperishable, not because of its 
 sensitive nature, but because it possesses rationality. If the soul 
 be thus capable only of being sensitive, it is perishable; but if it 
 has with the sensitive nature also rationality, it is imperishable. 
 For though the sensitive does not impart incorruptibility, 
 nevertheless it is impossible to dissociate incorruptibility from 
 the rational. 
 
 II. Forms do not belong to species and to genus, but the 
 composites. Man however is mortal, as are all other animals. 
 The difference therefore between the perishable and imperish- 
 able, which proceeds from the forms, does not cause man to 
 differ in genus from the other animals. 
 
 III. The embryo has at first only a sensitive soul. If this be 
 superseded, it receives a more perfect one, which is both sensi- 
 tive and rational. 1 
 
 IV. One should not apply different kinds of reasoning or 
 logical deduction, which are involved in methods of cognition, 
 to determine diversity in natural object. For in reasoning it is 
 possible to apprehend one and the same thing in different ways. 
 Hence, since the rational soul contains in its powers everything 
 that belongs to the sensitive soul, and also something more; the 
 reason too can distinguish from itself, what pertains to the 
 powers of the sensitive soul, and regard it as something in- 
 complete and material. Moreover, because it finds this incom- 
 pleteness to be something common to man and toother animals, 
 it formulates therefrom the nature of the genus. But that in 
 which the rational soul exceeds and surpasses the sensitive 
 soul, it regards as the forming and perfecting principle which 
 differentiates the being of man. 
 
 1 This is more fully developed by Thomas Aquinas in Question cxvm, 
 Art. 2 of the Summa Theolorica.
 
 SUMMA THEOLOGICA 143 
 
 QUESTION LXXVI. THE RELATION OF SOUL 
 AND BODY 
 
 Article VI. Is the Soul united to the Body without any further 
 Intermediation ? 
 
 (a) IT would appear that the rational soul is united to the 
 body by the intermediation of certain special properties. For: 
 
 I. Every form exists in matter suited and adjusted to it. But 
 such preadjustment to the form is effected by certain accidents. 
 Hence some accidental properties must be thought present 
 in matter before the entrance of the soul as substantial form. 
 
 II. Different forms of one and the same species are adapted 
 to different parts of matter. But different parts presuppose the 
 apportioning of measurable quantities. Therefore one cannot 
 assume such apportioning of matter before the entrance of sub- 
 stantial forms, of which many unite in one species. 
 
 III. The spiritual effects the body through its operating 
 activity. But the activity of the soul is its intellectual power. 
 Therefore the soul is united to the body by means of its intel- 
 lectual power, which is so to speak an accidental property. 
 
 But on the other hand it should be said: Every such property 
 exists posterior to substance, and thus presupposes both time 
 and reason (7 Metaph.). Therefore the accidental form cannot 
 be thought as existing in the matter before the soul is there 
 as substantial form. 
 
 (b) I answer: if the soul were only the mover of the body, 
 nothing need be said against this view. On the contrary, it 
 would be necessary to assume that particular properties in- 
 termediate between soul and body; namely, upon the part of the 
 soul the ability to move the body, and upon the part of the 
 body, its moveability. 
 
 But since the rational soul is the substantial form of the 
 body, it is impossible that there should be any accidental inter- 
 mediation between the soul and body, or between any sub- 
 stantial form and its matter. Since matter is potentially dis- 
 posed in a certain order for all actualities, that which in point
 
 144 THOMAS AQUINAS 
 
 of simplicity is first in actualities is first in matter. But the first 
 of all actualities is being. It is impossible, therefore, to conceive 
 a substance as either cold, or to have size, before it has actual 
 existence. But everything has actual existence in virtue of its 
 substantial form. Therefore, it is impossible that there should 
 be any preparatory accidental quality in the matter before the 
 substantial form; and consequently nothing in the body before 
 the soul. 
 
 (c) To the first position we must say, as is clear from the 
 previous discussion, that a form of more perfect powers com- 
 prises whatever inferior forms there are. Therefore one and the 
 same existing form perfects its matter in different grades of 
 perfection. It is one and the same essential form by which man 
 has being, possesses body, is living, is animal, and is man. It 
 is now apparent, that certain peculiar properties correspond to 
 every one of these different kinds of actuality. Hence as matter 
 is conceived as perfected in being before it can be apprehended 
 as corporeal, so the properties which accompany being are 
 conceived before their incorporation. So too adjustments of 
 matter are conceived before the form, not as if these were 
 present in actual being, but because they accompany its 
 activities. 
 
 II. The kinds of magnitude which are the necessary proper- 
 ties of materiality, correspond to those which belong in general to 
 matter. Matter, therefore, can be viewed as already corporeal, 
 and of various magnitudes, and yet be regarded as different in 
 its various parts; and therefore as capable of receiving a further 
 degree of perfection in its diverse forms. For though it is always 
 one and the same form in its essence, through which the differ- 
 ent degrees of perfection are attributed to matter, still reason 
 makes distinctions in these perfections. 
 
 III. The spiritual substance that is united to the body 
 merely as its motive force, is united to it by its potential and 
 actual powers. But the intellective soul is united to the body, 
 as form in its absolute essence. It however regulates the body 
 by its potential and actual powers.
 
 SUMMA THEOLOGICA 145 
 
 QUESTION LXXXIL THE SUPERIORITY OF 
 REASON TO WILL 
 
 Article III. Is the Nature of Reason superior to that of Will ? 
 
 (a) This appears not to be the case. For: 
 
 I. The final cause or the good is the object of the will. But 
 the final cause is the first and highest of causes. The will, there- 
 fore, is the first and highest of the faculties. 
 
 II. Natural objects ascend from the imperfect to the perfect. 
 Thus also in the faculties of the soul, the order of progress is from 
 the senses to the reason, which is superior. But the natural pro- 
 cess is from an act of mind to an act of will. The will is there- 
 fore superior to and more perfect than the intellect. 
 
 III. States of mind correspond to their potencies. But love 
 which is a state of mind achieved by the will stands as the 
 highest virtue. For it is written : " Though I know all mysteries 
 and have all faith but have not love I am nothing." i Cor. 13, 
 v. 2. The will is therefore a higher potency than the intellect. 
 
 On the other hand, Aristotle gives (10 Ethics, 7) the first 
 place- among the faculties to reason. 
 
 i. I answer, the rank of a faculty in relation to others can 
 be viewed: (i) in accordance to the nature possessed by each 
 absolutely; and (2) in accordance to a certain aspect only 
 relatively. 
 
 If the first view be considered, it is self-evident that the 
 reason is superior to the will. For the nature of a faculty is 
 judged according to its objects. Now the object of the reason 
 is more simple, absolute, and less conditioned, than that of 
 the will. For the object of the reason is the very idea of de- 
 sirable good. The will however is directed towards a desirable 
 good, the idea of which is in the reason. Now the more simple, 
 the less conditioned, and the more detached from particulars, 
 anything is, so much the higher does it stand in the rank and 
 the value of its being. The faculty of reason is, therefore, in 
 its nature more noble, and more sublime, than that of the will. 
 
 Relatively, however, and in comparison with something else,
 
 146 THOMAS AQUINAS 
 
 it may chance at times that the will stands higher than the 
 intellect. This is true because the object of the will may belong 
 to a higher type of being than the object of the reason. Thus I 
 could say that hearing is superior to sight, because the object 
 from which the object proceeds is more noble than that which 
 has the color, although color in itself may stand higher and be 
 purer than sound. In a similar manner, the action of the intel- 
 lect consists in this, that the nature of the thing known is com- 
 prehended by the knower; but the action of the will is con- 
 summated in the will's inclining to the object as it is in itself, 
 whatever its nature may be. For this reason, Aristotle says, 
 "good and evil which are the objects of the will belong to 
 things; true and false which are objects of the intellect belong 
 to the mind " (6 Metaph.}. When, therefore, the actual being in 
 which the good exists as object of reason, is superior to the soul 
 itself in which its nature is comprehended, then in comparison 
 to such an object, the will is superior to the reason. But if the 
 desired object is lower than the soul, then the reason in com- 
 parison to such an object is superior to the will. It is, there- 
 fore, better to love God, than merely to know God; and, con- 
 versely,- it is better only to know corporeal things, than to 
 love them. Nevertheless absolutely, reason is superior to will. 
 
 (c) II. Whatever is earlier in time or origin is the more 
 imperfect. For in one and the same thing, the potency pre- 
 cedes activity. At first there is the imperfect, later the per- 
 fected. But that which is before absolutely, and according to 
 the order of nature, is the more perfect. Thus the activity is 
 earlier than the potency. And in like manner, the reason 
 precedes the will, as the moving force precedes that which is 
 moved, and as activity precedes the affected. For in so far as 
 the good is conceived by the reason, it moves the will. 
 
 III. Through love we cleave to God, who is transcendently 
 raised above the soul. For that reason, the will is in this in- 
 stance superior to the reason.
 
 THOMAS HOBBES 
 
 (1588-1679) 
 
 HUMAN NATURE* 
 
 CHAPTER I. INTRODUCTION 
 
 1. THE true and perspicuous explication of the elements of 
 laws natural and politic (which is my present scope) dependeth 
 upon the knowledge of what is human nature, what is body politic, 
 and what it is we call a law; concerning which points, as the writ- 
 ings of men from antiquity downwards have still increased, so 
 also have the doubts and controversies concerning the same : and 
 seeing that true knowledge begetteth not doubt nor controversy, 
 but knowledge, it is manifest from the present controversies, 
 that they, which have heretofore written thereof, have not well 
 understood their own subject. 
 
 2. Harm I can do none, though I err no less than they; for I 
 shall leave men but as they are, in doubt and dispute: but, in- 
 tending not to take any principle upon trust, but only to put 
 men in mind of what they know already, or may know by their 
 own experience, I hope to err the less; and when I do, it must 
 proceed from too hasty concluding, which I will endeavour as 
 much as I can to avoid. 
 
 3 . On the other side, if reasoning aright win not consent, which 
 may very easily happen, from them that being confident of 
 their own knowledge weigh not what is said, the fault is not 
 mine, but theirs; for as it is my part to shew my reasons, so it is 
 theirs to bring attention. 
 
 4. Man's nature is the sum of his natural faculties and powers, 
 as the faculties of nutrition, motion, generation, sense, reason, 
 
 * Humane Nature, or the fundamental elements of policie. London, 1651. Re- 
 printed here from Hobbes' English Works, collected and edited by Sir William 
 Molesworth, London, 1839, vol. iv.
 
 148 THOMAS HOBBES 
 
 &. These powers we do unanimously call natural, and are con- 
 tained in the definition of man, under these words, animal and 
 rational. 
 
 5. According to the two principal parts of man, I divide his 
 faculties into two sorts, faculties of the body, and faculties of the 
 mind. 
 
 6. Since the minute and distinct anatomy of the powers of 
 the body is nothing necessary to the present purpose, I will only 
 sum them up in these three heads, power nutritive, power mo- 
 tive, and power generative. 
 
 7. Of the powers of the mind there be two sorts; cognitive, 
 imaginative, or conceptive, and motive; and first of cognitive. 
 
 For the understanding of what I mean by the power cogni- 
 tive, we must remember and acknowledge that there be in our 
 minds continually certain images or conceptions of the things 
 without us, insomuch that if a man could be alive, and all the 
 rest of the world annihilated, he should nevertheless retain the 
 image thereof, and all those things which he had before seen or 
 perceived in it; every one by his own experience knowing, that 
 the absence or destruction of things once imagined doth not cause 
 the absence or destruction of the imagination itself. This imagery 
 and representations of the qualities of the thing without, is that 
 we call our conception, imagination, ideas, notice or knowledge of 
 them ; and the faculty or power by which we are capable of such 
 knowledge, is that I here call cognitive power, or conceptive, the 
 power of knowing or conceiving. 
 
 CHAPTER II. THE SENSE AND ITS MAIN 
 DECEPTION 
 
 1. HAVING declared what I mean by the word conception, 
 and other words equivalent thereunto, I come to the concep- 
 tions themselves, to shew their differences, their causes, and 
 the manner of the production, so far as is necessary for this 
 place. 
 
 2. Originally all conceptions proceed from the action of the 
 thing itself, whereof it is the conception : now when the action is
 
 HUMAN NATURE 149 
 
 present, the conception it produceth is also called sense; and the 
 thing by whose action the same is produced, is called the object 
 of the sense. 
 
 3. By our several organs we have several conceptions of sev- 
 eral qualities in the objects ; for by sight we have a conception or 
 image composed of colour and figure, which is all the notice and 
 knowledge the object imparteth to us of its nature by the eye. 
 By hearing we have a conception called sound, which is all the 
 knowledge we have of the quality of the object from the ear. 
 And so the rest of the senses are also conceptions of several 
 qualities, or natures of their objects. 
 
 4. Because the image in vision consisting of colour and shape 
 is the knowledge we have of the qualities of the object of that 
 sense; it is no hard matter for a man to fall into this opinion, 
 that the same colour and shape are the very qualities themselves; 
 and for the same cause, that sound and noise are the qualities of 
 the bell, or of the air. And this opinion hath been so long re- 
 ceived, that the contrary must needs appear a great paradox; 
 and yet the introduction of species visible and intelligible (which 
 is necessary for the maintenance of that opinion) passing to and 
 fro from the object, is worse than any paradox, as being a plain 
 impossibility. I shall therefore endeavour to make plain these 
 points: 
 
 That the subject wherein colour and image are inherent, is 
 not the object or thing seen. 
 
 That there is nothing without us (really) which we call an 
 image or colour. 
 
 That the said image or colour is but an apparition unto us 
 of the motion, agitation, or alteration, which the object work- 
 eth in the brain, or spirits, or some internal substance of the 
 head. 
 
 That as in vision, so also in conceptions that arise from the 
 other senses, the subject of their inherence is not the object, but 
 the sentient. 
 
 i 5. Every man hath so much experience as to have seen the 
 sun and the other visible objects by reflection in the water and 
 glasses; and this alone is sufficient for this conclusion, that col-
 
 ISO THOMAS HOBBES 
 
 our and image may be there where the thing seen is not. But 
 because it may be said that notwithstanding the image in the 
 water be not in the object, but a thing merely phantastical, yet 
 there may be colour really in the thing itself: I will urge further 
 this experience, that divers times men see directly the same 
 object double, as two candles for one, which may happen from 
 distemper, or otherwise without distemper if a man will, the 
 organs being either in their right temper, or equally distem- 
 pered; the colours and figures in two such images of the same 
 thing cannot be inherent therein, because the thing seen cannot 
 be in two places. 
 
 One of these images therefore is not inherent in the object: 
 but seeing the organs of the sight are then in equal temper 
 or distemper, the one of them is no more inherent than the 
 other; and consequently neither of them both are in the object; 
 which is the first proposition, mentioned in the precedent 
 number. 
 
 6. Secondly, that the image of any thing by reflection in a 
 glass or water or the like, is not any thing in or behind the glass, 
 or in or under the water, every man may grant to himself; which 
 is the second proposition. 
 
 7. For the third, we are to consider, first that upon every 
 great agitation or concussion of the brain (as it happeneth from a 
 stroke, especially if the stroke be upon the eye) whereby the 
 optic nerve suffereth any great violence, there appeareth before 
 the eyes a certain light, which light is nothing without, but an 
 apparition only, all that is real being the concussion or motion 
 of the parts of that nerve ; from which experience we may con- 
 clude, that apparition of light is really nothing but motion within. 
 If therefore from lucid bodies there can be derived motion, so as 
 to affect the optic nerve in such manner as is proper thereunto, 
 there will follow an image of light somewhere in that line by 
 which the motion was last derived to the eye ; that is to say, in 
 the object, if we look directly on it, and in the glass or water, 
 when we look upon it in the line of reflection, which in effect 
 is the third proposition; namely, that image and colour is but 
 an apparition to us of that motion, agitation, or alteration
 
 HUMAN NATURE 151 
 
 which the object worketh in the brain or spirits, or some internal 
 substance in the head. 
 
 8. But that from all lucid, shining and illuminate bodies 
 there is a motion produced to the eye, and, through the eye, to 
 the optic nerve, and so into the brain, by which that apparition 
 of light or colour is affected, is not hard to prove. And first, it is 
 evident that the fire, the only lucid body here upon earth, 
 worketh by motion equally every way ; insomuch as the motion 
 thereof stopped or inclosed, it is presently extinguished, and no 
 more fire. And further, that that motion, whereby the fire work- 
 eth, is dilation, and contraction of itself alternately, commonly 
 called scintillation or glowing, is manifest also by experience. 
 From such motion in the fire must needs arise a rejection or cast- 
 ing from itself of that part of the medium which is contiguous 
 to it, whereby that part also rejecteth the next, and so success- 
 ively one part beateth back another to the very eye; and in the 
 same manner the exterior part of the eye presseth the interior, 
 (the laws of refraction still observed). Now the interior coat of 
 the eye is nothing else but a piece of the optic nerve ; and there- 
 fore the motion is still continued thereby into the brain, and by 
 resistance or reaction of the brain, is also a rebound into the optic 
 nerve again ; which we not conceiving as motion or rebound from 
 within, do think it is without, and call it light; as hath been al- 
 ready shewed by the experience of a stroke. We have no reason 
 to doubt, that the fountain of light, the sun, worketh by any 
 other ways than the fire, at least in this matter. And thus all 
 vision hath its original from such motion as is here described : 
 for where there is no light, there is no sight; and therefore colour 
 also must be the same thing with light, as being the effect of the 
 lucid bodies: their difference being only this, that when the light 
 cometh directly from the fountain to the eye, or indirectly by 
 reflection from clean and polite bodies, and such as have not any 
 particular motion internal to alter it, we call it light; but when it 
 cometh to the eye by reflection from uneven, rough, and coarse 
 bodies, or such as are affected with internal motion of their own 
 that may alter it, then we call it colour; colour and light differ- 
 ing only in this, that the one is pure, and the other perturbed
 
 152 THOMAS HOBBES 
 
 light. By that which hath been said, not only the truth of the 
 third proposition, but also the whole manner of producing light 
 and colour, is apparent. 
 
 9. As colour is not inherent in the object, but an effect thereof 
 upon us, caused by such motion in the object, as hath been 
 described: so neither is sound in the thing we hear, but in our- 
 selves. One manifest sign thereof is, that as a man may see, so 
 also he may hear double or treble, by multiplication of echoes, 
 which echoes are sounds as well as the original ; and not being in 
 one and the same place, cannot be inherent in the body that 
 maketh them. Nothing can make any thing which is not in it- 
 self: the clapper hath no sound in it, but motion, and maketh 
 motion in the internal parts of the bell ; so the bell hath motion, 
 and not sound, that imparteth motion to the air; and the air 
 hath motion, but not sound; the air imparteth motion by the 
 ear and nerve unto the brain; and the brain hath motion but not 
 sound; from the brain, it reboundeth back into the nerves out- 
 ward, and thence it becometh an apparition without, which we 
 call sound. And to proceed to the rest of the senses, it is appar- 
 ent enough, that the smell and taste of the same thing, are not the 
 same to every man; and therefore are not in the thing smelt or 
 tasted, but in the men. So likewise the heat we feel from the fire 
 is manifestly in us, and is quite different from the heat which is 
 in the fire: for our heat is pleasure or pain, according as it is 
 great or moderate; but in the coal there is no such thing. By this 
 the fourth and last proposition is proved, viz. that as in vision, 
 so also in conceptions that arise from other senses, the subject 
 of their inherence is not in the object, but in the sentient. 
 
 10. And from hence also it followeth, that whatsoever acci- 
 dents or qualities our senses make us think there be in the world, 
 they be not there, but are seeming and apparitions only: the 
 things that really are in the world without us, are those motions 
 by which these seemings are caused. And this is the great decep- 
 tion of sense, which also is to be by sense corrected: for as sense 
 telleth me, when I see directly, that the colour seemeth to be in 
 the object ; so also sense telleth me, when I see by reflection, what 
 colour is not in the object.
 
 HUMAN NATURE 153 
 
 CHAPTER III. IMAGINATION AND DREAMS 
 
 1. As standing water put into motion by the stroke of a 
 stone, or blast of wind, doth not presently give over moving as 
 soon as the wind ceaseth, or the stone settleth : so neither doth 
 the effect cease which the object hath wrought upon the brain, 
 so soon as ever by turning aside of the organs the object ceaseth 
 to work ; that is to say, though the sense be past, the image or 
 conception remaineth ; but more obscure while we are awake, be- 
 cause some object or other continually plieth and soliciteth our 
 eyes, and ears, keeping the mind in a stronger motion, whereby 
 the weaker doth not easily appear. And this obscure concep- 
 tion is that we call phantasy, or imagination: imagination being, 
 to define it, conception remaining, and by little and little decay- 
 ing from after and the act of sense. 
 
 2. But when present sense is not, as in sleep, there the images 
 remaining after sense, when there be many, as in dreams, are 
 not obscure, but strong and clear, as in sense itself. The reason is, 
 that which obscured and made the conceptions weak, namely 
 sense, and present operation of the object, is removed: for sleep 
 is the privation of the act of sense, (the power remaining) and 
 dreams are the imagination of them that sleep. 
 
 3. The causes of dreams, if they be natural, are the actions or 
 violence of the inward parts of a man upon his brain, by which 
 the passages of sense by sleep benumbed, are restored to their 
 motion. The signs by which this appeareth to be so, are the 
 differences of dreams (old men commonly dream oftener, and 
 have their dreams more painful than young) proceeding from 
 the different accidents of man's body, as dreams of lust, as 
 dreams of anger, according as the heart, or other parts within, 
 work more or less upon the brain, by more or less heat; so also 
 the descents of different sorts of phlegm maketh us a dream of 
 different tastes of meats and drinks; and I believe there is a 
 reciprocation of motion from the brain to the vital parts, and 
 back from the vital parts to the brain ; whereby not only imagin- 
 ation begetteth motion m those parts; but also motion in those 
 parts begetteth imagination like to that by which it was begot-
 
 154 THOMAS HOBBES 
 
 ten. If this be true, and that sad imaginations nourish the 
 spleen, then we see also a cause, why a strong spleen recipro- 
 cally causeth fearful dreams, and why the effects of lascivious- 
 ness may in a dream produce the image of some person that had 
 caused them. Another sign that dreams are caused by the action 
 of the inward parts, is the disorder and casual consequence of 
 one conception or image to another: for when we are waking, 
 the antecedent thought or conception introduceth, and is cause 
 of the consequent, as the water followeth a man's finger upon a 
 dry and level table; but in dreams there is commonly no coher- 
 ence, and when there is, it is by chance, which must needs pro- 
 ceed from this, that the brain in dreams is not restored to its 
 motion in every part alike; whereby it cometh to pass, that our 
 thoughts appear like the stars between the flying clouds, not in 
 the order which a man would choose to observe them, but as the 
 uncertain flight of broken clouds permits. 
 
 4. As when the water, or any liquid thing moved at once by 
 divers movements, receiveth one motion compounded of them 
 all; so also the brain or spirit therein, having been stirred by 
 divers objects, composeth an imagination of divers conceptions 
 that appeared single to the sense. As for example, the sense 
 sheweth at one time the figure of a mountain, and at another 
 time the colour of gold; but the imagination afterwards hath 
 them both at once in a golden mountain. From the same cause 
 it is, there appear unto us castles in the air, chimeras, and other 
 monsters which are not in rerum natura, but have been conceived 
 by the sense in pieces at several times. And this composition is 
 that which we commonly call fiction of the mind. 
 
 5. There is yet another kind of imagination, which for clear- 
 ness contendeth with sense, as well as a dream; and that is, when 
 the action of sense hath been long or vehement: and the experi- 
 ence thereof is more frequent in the sense of seeing, than the 
 rest. An example whereof is, the image remaining before the 
 eye after looking upon the sun. Also, those little images that 
 appear before the eyes in the dark (whereof I think every man 
 hath experience, but they most of all, who are timorous or 
 superstitious) are examples of the same. And these, for distinc- 
 tion-sake, may be called phantasms.
 
 HUMAN NATURE 155 
 
 6. By the senses, which are numbered according to the or- 
 gans to be five, we take notice (as hath been said already) of the 
 objects without us; and that notice is our conception thereof: but 
 we take notice also some way or other of our conceptions: for when 
 the conception of the same thing cometh again, we take notice 
 that it is again; that is to say, that we have had the same con- 
 ception before; which is as much as to imagine a thing past; 
 which is impossible to the sense, which is only of things present. 
 This therefore may be accounted a sixth sense, but internal, (not 
 external, as the rest) and is commonly called remembrance. 
 
 7. For the manner by which we take notice of a conception 
 past, we are to remember, that in the definition of imagination, 
 it is said to be a conception by little and little decaying, or growing 
 more obscure. An obscure conception is that which representeth 
 the whole object together, but none of the smaller parts by them- 
 selves; and as more or fewer parts be represented, so is the con- 
 ception or representation said to be more or less clear.- Seeing 
 then the conception, which when it was first produced by sense, 
 was clear, and represented the parts of the object distinctly; and 
 when it cometh again is obscure, we find missing somewhat that 
 we expected ; by which we judge it past and decayed. For exam- 
 ple, a man that is present in a foreign city, seeth not only whole 
 streets, but can also distinguish particular houses, and parts of 
 houses; but departed thence, he cannot distinguish them so 
 particularly in his mind as he did, some house or turning escap- 
 ing him ; yet is this to remember; when afterwards there escape 
 him more particulars, this is also to remember, but not so well. In 
 process of time, the image of the city returneth but as a mass of 
 building only, which is almost to have forgotten it. Seeing then 
 remembrance is more or less, as we find more or less obscurity, 
 why may not we well think remembrance to be nothing else but 
 the missing of parts, which every man expecteth should succeed 
 after they have a conception of the whole? To see at a great 
 distance of place, and to remember at a great distance of time, 
 is to have like conceptions of the thing: for there wanteth dis- 
 tinction of parts in both; the one conception being weak by 
 operation at distance, the other by decay.
 
 156 THOMAS HOBBES 
 
 8. And from this that hath been said, there followeth, that a 
 man can never know he dreameth; he may dream he doubteth, 
 whether it be a dream or no : but the clearness of the imagina- 
 tion representeth every thing with as many parts as doth sense 
 itself, and consequently, he can take notice of nothing but as 
 present; whereas to think he dreameth, is to think those his con- 
 ceptions, that is to say dreams, obscurer than they were in the 
 sense; so that he must think them both as clear, and not as 
 clear as sense; which is impossible. 
 
 9. From the same ground it proceedeth, that men wonder not 
 in their dreams at place and persons, as they would do waking: 
 for waking, a man would think it strange to be in a place where 
 he never was before, and remember nothing of how he came 
 there; but in a dream, there cometh little of that kind into con- 
 sideration. The clearness of conception in a dream, taketh away 
 distrust, unless the strangeness be excessive, as to think himself 
 fallen from on high without hurt, and then most commonly he 
 waketh. 
 
 10. Nor is it impossible for a man to be so far deceived, as 
 when his dream is past, to think it real : for if he dream of such 
 things as are ordinarily in his mind, and in such order as he 
 useth to do waking, and withal that he laid him down to sleep 
 in the place where he findeth himself when he awaketh; all 
 which may happen: I know no Kpirijpiov or mark by which he 
 can discern whether it were a dream or not, and therefore do 
 the less wonder to hear a man sometimes to tell his dream for a 
 truth, or to take it for a vision, 
 
 CHAPTER IV. THOUGHT 
 
 i . THE succession of conceptions in the mind, series or conse- 
 quence of one after another, may be casual and incoherent, as in 
 dreams for the most part; and it may be orderly, as when the 
 former thought introduceth the latter; and this is discourse of 
 the mind. But because the word discourse is commonly taken 
 for the coherence and consequence of words, I will, to avoid 
 equivocation, call it discursion.
 
 HUMAN NATURE 157 
 
 2. The cause of the coherence or consequence of one concep- 
 tion to another, is their first coherence or consequence at that 
 time when they are produced by sense: as for example, from St. 
 Andrew the mind runneth to St. Peter, because their names are 
 read together; from St. Peter to a stone, for the same cause; from 
 stone to foundation, because we see them together; and for the 
 same cause, from foundation to church, and from church to 
 people, and from people to tumult: and according to this exam- 
 ple, the mind may run almost from anything to anything. But 
 as in the sense the conception of cause and effect may succeed 
 one another ; so may they after sense in the imagination: and for 
 the most part they do so; the cause whereof is the appetite of 
 them, who, having a conception of the end, have next unto it a 
 conception of the next means to that end: as, when a man, from 
 a thought of honour to which he hath an appetite, cometh to the 
 thought of "wisdom, which is the next means thereunto; and 
 from thence to the thought of study, which is the next means to 
 wisdom. 
 
 3. To omit that kind of discursion by which we proceed from 
 anything to anything, there are of the other kind divers sorts : as 
 first, in the senses there are certain coherences of conceptions, 
 which we may call ranging; examples whereof are; a man cast- 
 eth his eye upon the ground, to look about for some small thing 
 lost; the hounds casting about at a fault in hunting; and the 
 ranging of spaniels : and herein we take a beginning arbitrary. 
 
 4. Another sort of discursion is, when the appetite giveth a 
 man his beginning, as in the example before, where honour to 
 which a man hath appetite, maketh him think upon the next 
 means of attaining it, and that again of the next, &c. And this 
 the Latins call sagacitas, and we may call hunting or tracing, 
 as dogs trace beasts by the smell, and men hunt them by 
 their footsteps; or as men hunt after riches, place, or know- 
 ledge. 
 
 5. There is yet another kind of discursion beginning with the 
 appetite to recover something lost, proceeding from the present 
 backward, from thought of the place where we miss at, to the 
 thought of the place from whence we came last; and from the
 
 i$8 THOMAS HOBBES 
 
 thought of that, to the thought of a place before, till we have in 
 our mind some place, wherein we had the thing we miss: and 
 this is called reminiscence. 
 
 6. The remembrance of succession of one thing to another, 
 that is, of what was antecedent, and what consequent, and what 
 concomitant, is called an experiment; whether the same be made 
 by us voluntarily, as when a man putteth any thing into the fire, 
 to see what effect the fire will produce upon it : or not made by 
 us, as when we remember a fair morning after a red evening. 
 To have had many experiments, is that we call experience, which 
 is nothing else but remembrance of what antecedents have been 
 followed by what consequents. 
 
 7. No man can have in his mind a conception of the future, 
 for the future is not yet : but of our conceptions of the past, we 
 make a. future; or rather, call past, future relatively. Thus after 
 a man hath been accustomed to see like antecedents followed 
 by like consequents, whensoever he seeth the like come to pass 
 to any thing he had seen before, he looks there should follow 
 it the same that followed then: as for example, because a man 
 hath often seen offences followed by punishment, when he 
 seeth an offence in present, he thinketh punishment to be con- 
 sequent thereunto; but consequent unto that which is present, 
 men call future; and thus we make remembrance to be the pre- 
 vision of things to come, or expectation or presumption of the 
 future. 
 
 8. In the same manner, if a man seeth in present that which 
 he hath seen before, he thinks that that which was antecedent 
 to that which he saw before, is also antecedent to that he pre- 
 sently seeth: as for example, he that hath seen the ashes remain 
 after the fire, and now again seeth ashes, concludeth again 
 there hath been fire : and this is called again conjecture of the past, 
 or presumption of the fact. 
 
 9. When a man hath so often observed like antecedents to be 
 followed by like consequents, that whensoever he seeth the ante- 
 cedent, he looketh again for the consequent; or when he seeth 
 the consequent, maketh account there hath been the like ante- 
 cedent; then he calleth both the antecedent and the consequent,
 
 HUMAN NATURE 159 
 
 signs one of another, as clouds are signs of rain to come, and 
 rain of clouds past. 
 
 10. This taking of signs by experience, is that wherein men 
 do ordinarily think, the difference stands between man and man 
 in wisdom, by which they commonly understand a man's whole 
 ability or power cognitive; but this is an error: for the signs are 
 but conjectural; and according as they have often or seldom 
 failed, so their assurance is more or less; but never full and evi- 
 dent : for though a man have always seen the day and night to 
 follow one another hitherto; yet can he not thence conclude 
 they shall do so, or that they have done so eternally: experi- 
 ence concludeth nothing universally. If the signs hit twenty times 
 for one missing, a man may lay a wager of twenty to one of the 
 event; but may not conclude it for a truth. But by this it is 
 plain, that they shall conjecture lest, that have most experience, 
 because they have most signs to conjecture by: which is the 
 reason old men are more prudent, that is, conjecture better, 
 cateris paribus, than young: for, being old, they remember 
 more; and experience is but remembrance. And men of quick 
 imagination, cceteris paribus, are more prudent than those whose 
 imaginations are slow : for they observe more in less time. Prud- 
 ence is nothing but conjecture from experience, or taking of 
 signs from experience warily, that is, that the experiments from 
 which he taketh such signs be all remembered ; for else the cases 
 are not alike that seem so. 
 
 11. As in conjecture concerning things past and future, it is 
 prudence to conclude from experience, what is like to come to 
 pass, or to have passed already; so it is an error to conclude 
 from it, that it is so or so called; that is to say, we cannot from 
 experience conclude, that any thing is to be catted just or unjust, 
 true or false, or any proposition universal whatsoever, except 
 it be from remembrance of the use of names imposed arbitrarily 
 by men: for example, to have heard a sentence given in the like 
 case, the like sentence a thousand times is not enough to con- 
 clude that the sentence is just; though most men have no other 
 means to conclude by : but it is necessary, for the drawing of such 
 conclusion, to trace and find out, by many experiences, what men
 
 160 THOMAS HOBBES 
 
 do mean by calling things just and unjust. Further, there is 
 another caveat to be taken in concluding by experience, from 
 the tenth section of the second chapter; that is, that we con- 
 clude such things to be without, that are within us. 
 
 CHAPTER VI. KNOWLEDGE AND BELIEF 
 
 1. THERE is a story somewhere, of one that pretends to have 
 been miraculously cured of blindness, wherewith he was born, 
 by St. Alban or other Saints, at the town of St. Alban's; and 
 that the Duke of Gloucester being there, to be satisfied of the 
 truth of the miracle, asked the man, What colour is this? who, 
 by answering, it was green, discovered himself, and was pun- 
 ished for a counterfeit: for though by his sight newly received 
 he might distinguish between green, and red, and all other col- 
 ours, as well as any that should interrogate him, yet he could 
 not possibly know at first sight which of them was called green, 
 or red, or by any other name. By this we may understand, 
 there be two kinds of knowledge, whereof the one is nothing else 
 but sense, or knowledge original, as I have said in the beginning 
 of the second chapter, and remembrance of the same; the other is 
 called science or knowledge of the truth of propositions, and how 
 things are called, and is derived from understanding. Both of 
 these sorts are but experience; the former being the experience 
 of the effects of things that work upon us from without; and the 
 latter experience men have from the proper use of names in 
 language: and all experience being, as I have said, but remem- 
 brance, all knowledge is remembrance: and of the former, the 
 register we keep in books, is called history; but the registers of 
 the latter are called the sciences. 
 
 2. There are two things necessarily implied in this word 
 knowledge; the one is truth, the other evidence; for what is not 
 truth, can never be known. For, let a man say he knoweth a 
 thing never so well, if the same shall afterwards appear false, 
 he is driven to confession, that it was not knowledge, but opin- 
 ion. Likewise, if the truth be not evident, though a man holdeth 
 it, yet is his knowledge thereof no more than theirs who hold
 
 HUMAN NATURE 161 
 
 the contrary: for if truth were enough to make it knowledge, 
 all truth were known; which is not so. 
 
 3. What truth is, hath been defined in the precedent chapter; 
 what evidence is, I now set down: and it is the concomitance of a 
 man's conception with the words that signify such conception 
 in the act of ratiocination: for when a man reasoneth with his 
 lips only, to which the mind suggesteth only the beginning, and 
 followeth not the words of his mouth with the conceptions of 
 his mind, out of custom of so speaking; though he begin his 
 ratiocination with true propositions, and proceed with certain 
 syllogisms, and thereby make always true conclusions ; yet are 
 not his conclusions evident to him, for want of the concomitance 
 of conception with his words: for if the words alone were suffi- 
 cient, a parrot might be taught as well to know truth, as to speak 
 it. Evidence is to truth, as the sap to the tree, which, so far as 
 it creepeth along with the body and branches, keepeth them 
 alive; where it forsaketh them, they die: for this evidence, which 
 is meaning with our words, is the life of truth. 
 
 4. Knowledge thereof, which we call science, I define to be 
 evidence of truth, from some beginning or principle of sense: for 
 the truth of a proposition is never evident, until we conceive the 
 meaning of the words or terms whereof it consisteth, which are 
 always conceptions of the mind: nor can we remember those 
 conceptions, without the thing that produced the same by our 
 senses. The first principle of knowledge is, that we have such 
 and such conceptions; the second, that we have thus and thus 
 named the things whereof they are conceptions; the third is, 
 that we have joined those names in such manner as to make 
 true propositions; the fourth and last is, that we have joined 
 those propositions in such manner as they be concluding, 
 and the truth of the conclusion said to be known. And of these, 
 two kinds of knowledge, whereof the former is experience of fact, 
 and the latter evidence of truth; as the former, if it be great, is 
 called prudence; so the latter, if it be much, hath usually been 
 called, both by ancient and modern writers, sapience or wisdom 
 and of this latter, man only is capable; of the former, brute beasts 
 also participate.
 
 162 THOMAS HOBBES 
 
 5. A proposition is said to be supposed, when, being not evi- 
 dent, it is nevertheless admitted for a time, to the end, that, join- 
 ing to it other propositions, we may conclude something; and to 
 proceed from conclusion to conclusion, for a trial whether the 
 same will lead us into any absurd or impossible conclusion; 
 which if it do, then we know such supposition to have been false. 
 
 6. But if running through many conclusions, we come to none 
 that are absurd, then we think the proposition probable; likewise 
 we think probable whatsoever proposition we admit for truth 
 by error of reasoning, or from trusting to other men : and all such 
 propositions as are admitted by trust or error, we are not said to 
 know, but to think them to be true; and the admittance of them 
 is called opinion. 
 
 7. And particularly, when the opinion is admitted out of 
 trust to other men, they are said to believe it; and their admit- 
 tance of it is called belief, and sometimes faith. 
 
 8. It is either science or opinion which we commonly mean 
 by the word conscience: for men say that such and such a thing 
 is true in or upon their conscience ; which they never do, when 
 they think it doubtful; and therefore they know, or think they 
 know it to be true. But men, when they say things upon their 
 conscience, are not therefore presumed certainly to know the 
 truth of what they say; it remaineth then, that that word is 
 used by them that have an opinion, not only of the truth of the 
 thing, but also of their knowledge of it, to which the truth of the 
 proposition is consequent. Conscience I therefore define to be 
 opinion of evidence. 
 
 9. Belief, which is the admitting of propositions upon trust, 
 in many cases is no less free from doubt, than perfect and mani- 
 fest knowledge : for as there is nothing whereof there is not some 
 jcause; so, when there is doubt, there must be some cause there- 
 of conceived. Now there be many things which we receive from 
 report of others, of which it is impossible to imagine any cause of 
 doubt for what can be opposed against the consent of all men, 
 in things they can know, and have no cause to report otherwise 
 than they are, such as is a great part of our histories, unless a 
 man would say that all the world had conspired to deceive him.
 
 HUMAN NATURE 163 
 
 And thus much of sense, imagination, discursion, ratiocina- 
 tion, and knowledge, which are the acts of our power cognitive, or 
 conceptive. That power of the mind which we call motive, dif- 
 fereth from the power motive of the body; for the power motive 
 of the body is that by which it moveth other bodies, and we call 
 strength : but the power motive of the mind, is that by which the 
 mind giveth animal motion to that body wherein it existeth ; the 
 acts hereof are our affections and passions, of which I am to 
 speak in general. 
 
 CHAPTER VII. THE PASSIONS 
 
 1. IN the eighth section of the second chapter is shewed, thai 
 conceptions and apparitions are nothing really, but motion in 
 some internal substance of the head; which motion not stopping 
 there, but proceeding to the heart, of necessity must there either 
 help or hinder the motion which is called vital; when it helpeth, 
 it is called delight, contentment, or pleasure, which is nothing 
 really but motion about the heart, as conception is nothing but 
 motion in the head: and the objects that cause it are called 
 pleasant or delightful, or by some name equivalent; the Latins 
 have jucundum, ajuvando, from helping; and the same delight, 
 with reference to the object, is called love : but when such motion 
 iveakeneth or hindereth the vital motion, then it is called pain; 
 and in relation to that which causeth it, hatred, which the 
 Latins express sometimes by odium, and sometimes by tcedium. 
 
 2. This motion, in which consisteth pleasure or pain, is also a 
 solicitation or provocation either to draw near to the thing that 
 pleaseth, or to retire from the thing that displeaseth; and this 
 solicitation is the endeavour or internal beginning of animal 
 motion, which when the object delighteth, is called appetite; 
 when it displeaseth, it is called aversion, in respect of the dis- 
 pleasure present; but in respect of the displeasure expected, fear. 
 So that, pleasure, love, and appetite, which is also called desire, 
 are divers names for divers considerations of the same thing. 
 
 3. Every man, for his own part, calleth that which pleaseth, 
 and is delightful to himself, good; and that evil which displeas-
 
 164 THOMAS HOBBES 
 
 eth him : insomuch that while every man differeth from another 
 in constitution, they differ also from one another concerning the 
 common distinction of good and evil. Nor is there any such 
 thing as absolute goodness, considered without relation: for 
 even the goodness which we apprehend in God Almighty, is his 
 goodness to us. And as we call good and evil the things that please 
 and displease; so call we goodness and badness, the qualities or 
 powers whereby they do it: and the signs of that goodness are 
 called by the Latins in one word pulchritudo, and the signs of 
 evil, turpitudo; to which we have no words precisely answerable. 
 As all conceptions we have immediately by the sense, are, 
 delight, or pain, or appetite, or fear; so are all the imaginations 
 after sense. But as they are weaker imaginations, so are they 
 also weaker pleasures, or weaker pain. 
 
 4. As appetite is the beginning of animal motion towards 
 something that pleaseth us ; so is the attaining thereof, the end 
 of that motion, which we also call the scope, and aim, and final 
 cause of the same: and when we attain that end, the delight we 
 have thereby is called tine fruition : so that bonum and finis are 
 different names, but for different considerations of the same 
 thing. 
 
 5. And of ends, some of them are called propinqui, that is, 
 near at hand; others remoti, far off: but when the ends that be 
 nearer attaining, be compared with those that be further off, 
 they are called not ends, but means, and the way to those. But 
 for an utmost end, in which the ancient philosophers have placed 
 felicity, and disputed much concerning the way thereto, there 
 is no such thing in this world, nor way to it, more than to 
 Utopia: for while we live, we have desires, and desire presup- 
 poseth a further end. Those things which please us, as the way 
 or means to a further end, we call profitable; and the fruition of 
 them, use; and those things that profit not, vain. 
 
 6. Seeing all delight is appetite, and presupposeth a, further 
 end, there can be no contentment but in proceeding : and there- 
 fore we are not to marvel, when we see, that as men attain to 
 more riches, honour, or other power; so their appetite continu- 
 ally groweth more and more; and when they are come to the
 
 HUMAN NATURE 165 
 
 utmost degree of some kind of power, they pursue some other, 
 as long as in any kind they think themselves behind any other: 
 of those therefore that have attained to the highest degree of 
 honour and riches, some have affected mastery in some art; as 
 Nero in music and poetry, Commodus in the art of a gladiator; 
 and such as affect not some such thing, must find diversion and 
 recreation of their thoughts in the contention either of play or 
 business: and men justly complain of a great grief, that they 
 know not what to do. Felicity, therefore, by which we mean 
 continual delight, consisteth not in having prospered, but in 
 prospering. 
 
 7. There are few things in this world, but either have mixture 
 0f good and evil, or there is a chain of them so necessarily linked 
 together, that the one cannot be taken without the other: as for 
 example, the pleasures of sin, and the bitterness of punishment, 
 are inseparable ; as is also labour and honour, for the most part. 
 Now when in the whole chain, the greater part is good, the whole 
 is called good; and when the evil over-weigheth, the whole is called 
 evil. 
 
 8. There are two sorts of pleasure, whereof the one seemeth 
 to affect the corporeal organ of the sense, and that I call sensual; 
 the greatest part whereof, is that by which we are invited to give 
 continuance to our species; and the next, by which a man is 
 invited to meat, for the preservation of his individual person: 
 the other sort of delight is not particular to any part of the body, 
 and is called the delight of the mind, and is that which we call 
 joy. Likewise of pains, some affect the body, and are therefore 
 called the pains of the body; and some not, and those are called 
 grief. 
 
 CHAPTER XII. THE WILL 
 
 i. IT hath been declared already, how eternal objects cause 
 conceptions, and conceptions, appetite and fear, which are the 
 first unperceived beginnings of our actions; for either the actions 
 immediately follow the first appetite, as when we do anything 
 upon a sudden; or else to our first appetite there succeedeth 
 some conception of evil to happen to us by such actions, which
 
 166 THOMAS HOBBES 
 
 is fear, and which holdeth us from proceeding. And to that fear 
 may succeed a new appetite, and to that appetite another fear 
 alternately, till the action be either done, or some accident come 
 between, to make it impossible; and so this alternate appetite 
 and fear cease th. This alternate succession of appetite and fear 
 during all the time the action is in our power to do or not to do, 
 is that we call deliberation; which name hath been given it for 
 that part of the definition wherein it is said that it lasteth so long 
 as the action, whereof we deliberate, is in our power: for, so 
 long we have liberty to do or not to do; and deliberation signi- 
 fieth a taking away of our own liberty. 
 
 2. Deliberation therefore requireth in the action deliberated 
 two conditions; one, that it be future; the other, that there be 
 hope of doing it, or possibility of not doing it; for, appetite and 
 fear are expectations of the future; and there is no expectation of 
 good, without hope; or of evil, without possibility : of necessaries 
 therefore there is no deliberation. In deliberation, the last appe- 
 tite, as also the last fear, is called will, viz. the last appetite, 
 will to do, or will to omit. It is all one therefore to say will and 
 last will; for, though a man express his present inclination and 
 appetite concerning the disposing of his goods, by words or 
 writings; yet shall it not be counted his will, because he hath 
 still liberty to dispose of them other ways : but when death taketh 
 away that liberty, then it is his will. 
 
 3. Voluntary actions and omissions are such as have begin- 
 ning in the will; all other are involuntary, or mixed voluntary; 
 involuntary, such as he doth by necessity of nature, as when he 
 is pushed, or falleth, and thereby doth good or hurt to another: 
 mixed, such as participate of both; as when a man is carried to 
 prison, going is voluntary, to the prison, is involuntary: the 
 example of him that throweth his goods out of a ship into the 
 sea, to save his person, is of an action altogether voluntary: for, 
 there is nothing therein involuntary, but the hardness of the 
 choice, which is not his action, but the action of the winds: 
 what he himself doth, is no more against his will, than to flee 
 from danger is against the will of him that seeth no other means 
 to preserve himself.
 
 HUMAN NATURE 167 
 
 4. Voluntary also are the actions that proceed from sudden 
 anger, or other sudden appetite in such men as can discern good 
 or evil: for, in them the time precedent is to be judged delibera- 
 tion: for then also he deliberateth in what cases it is good to 
 strike, deride, or do any other action proceeding from anger or 
 other such sudden passion. 
 
 5. Appetite, fear, hope, and the rest of the passions are not 
 called voluntary; for they proceed not from, but are the will; and 
 the will is not voluntary: for, a man can no more say he will 
 will, then he will will will, and so make an infinite repetition of 
 the word [will} ; which is absurd, and insignificant. 
 
 6. Forasmuch as will to do is appetite, and will to omit, fear; 
 the cause of appetite and/ear is the cause also of our will: but 
 the propounding of the benefits and of harms, that is to say, of 
 reward and punishment, is the cause of our appetite, and of our 
 fears, and therefore also of our wills, so far forth as we believe 
 that such rewards and benefits as are propounded, shall arrive 
 unto us ; and consequently, our wills follow our opinions, as our 
 actions follow our wills; in which sense they say truly, and pro- 
 perly, that say the world is governed by opinion. 
 
 7. When the wills of many concur to one and the same action 
 and effect, this concourse of their wills is called consent; by which 
 we must not understand one will of many men, for every man 
 hath his several will, but many wills to the producing of one 
 effect: but when the wills of two divers men produce such ac- 
 tions as are reciprocally resistant one to the other, this is called 
 contention; and, being upon the persons one of another, battle: 
 whereas actions proceeding from consent, are mutual aid. 
 
 8. When many wills are involved or included in the will of 
 one or more consenting, (which how it may be, shall be here- 
 after declared) then is that involving of many wills in one or 
 more, called union. 
 
 9. In deliberations interrupted, as they may be by diversion 
 of other business, or by sleep, the last appetite of such part of 
 the deliberation is called intention, or purpose.
 
 RENE DESCARTES 
 
 (1596-1650) 
 
 THE PASSIONS OF THE SOUL 
 
 Translated from the French * by 
 HENRY A. P. TORREY 
 
 PART I 
 
 ARTICLE I 
 
 Passion, as respects the subject, is always action in some other 
 respect. 
 
 THERE is nothing which better shows how defective the sci- 
 ences are which we have received from the ancients than what 
 they have written upon the passions ; for, although it is a sub- 
 ject the knowledge of which has always been much sought after, 
 and which does not appear to be one of the more difficult sci- 
 ences, because everyone, feeling the passions in himself, stands 
 in no need whatever of borrowing any observation elsewhere to 
 discover their nature, nevertheless, what the ancients have 
 taught on this subject is of such slight intent, and for the 
 most part sc untrustworthy, that I cannot have any hope of 
 reaching the truth, except by abandoning the paths which they 
 have followed. That is the reason why I shall be obliged to 
 write now in the same way as I should if I were treating a topic 
 which no one before me had ever touched upon; and, to begin 
 with, I take into consideration the fact that an event is gener- 
 ally spoken of by philosophers as a passion as regards the sub- 
 ject to which it happens, and an action in respect to that which 
 causes it; so that, although the agent and the patient may often 
 
 * From Les passions de I'dme, Amst. 1650. In (Entires, t. iv. Reprinted from 
 The Philosophy of Descartes, in Extracts from his Writings, selected and trans- 
 lated by Henry A. P. Torrey. New York, Henry Holt and Company, 1892.
 
 THE PASSIONS OF THE SOUL 169 
 
 be very different, action and passion are always one and the 
 same thing, which has these two names because of the two 
 different subjects to which it can be referred. 
 
 ARTICLE II 
 
 In order to understand the passions of the soul, it is necessary 
 to distinguish its functions from those of the body. 
 
 Next I take into consideration that we know of no subject 
 which acts more immediately upon our soul than the body to 
 which it is joined, and that consequently we must think that 
 what in the one is a passion is commonly in the other an ac- 
 tion; so that there is no better path to the knowledge of our 
 passions than to examine into the difference between the soul 
 and the body, in order to know to which of them is to be 
 attributed each of our functions. 1 
 
 ARTICLE III 
 
 The rule to be observed to this end. 
 
 No great difficulty will be found in this, if it be borne in mind 
 that all that which we experience in ourselves which we see can 
 also take place in bodies entirely inanimate is to be attributed 
 only to our body; and, on the contrary, all that which is in us 
 and which we cannot conceive in any manner possible to pertain 
 to a body is to be attributed to our soul. 
 
 ARTICLE IV 
 
 That heat and the movement of the limbs proceed from the body, 
 thoughts from the mind. 
 
 Thus, because we cannot conceive that the body thinks in 
 any manner whatever, we have no reason but to think that all 
 forms of thought which are in us belong to the mind ; and be- 
 cause we cannot doubt that there are inanimate bodies which 
 can move in as many or more different ways than ours, and 
 
 1 Cf. Meditation vi, in The Method, Meditations and Selections from the 
 Principles. Translated by John Veitch. Edin., 1850, etc.
 
 iyo RENE DESCARTES 
 
 which have as much or more heat (as experience teaches us in 
 the case of flame, which alone has more heat and motion than 
 any of our members), we must believe that all the heat and all 
 the motions which are in us, in so far as they do not depend at 
 all on thought, belong only to the body. 
 
 ARTICLE V 
 
 That it is an error to think that the soul imparts motion and heat 
 to the body. 
 
 By this means we shall avoid a very great error, into which 
 many have fallen, an error which I consider to be the principal 
 hindrance, up to the present time, to a correct explanation of 
 the passions and other properties of the soul. It consists in this, 
 that, seeing that all dead bodies are deprived of heat and, conse- 
 quently, of motion, it is imagined that the absence of the soul 
 causes these movements and this heat to cease; and thus it has 
 been thought, without reason, that our natural heat and all the 
 motions of our body depend upon the soul; instead of which it 
 should be thought, on the contrary, that soul departs, when 
 death occurs, only because this heat fails and the organs which 
 serve to move the body decay. 
 
 ARTICLE VI 
 
 The difference between a living and a dead body. 
 
 In order, then, that we may avoid this error, let us consider 
 that death never takes place through the absence of a soul, 
 but solely because some one of the principal parts of the body 
 has fallen into decay; and let us conclude that the body of a 
 living man differs as much from that of a dead man as does a 
 watch or other automaton (that is to say, or other machine 
 which moves of itself), when it is wound up, and has within 
 itself the material principle of the movements for which it is 
 constructed, with all that is necessary for its action, from the 
 same watch or other machine, when it has been broken, and the 
 principle of its movement ceases to act.
 
 THE PASSIONS OF THE SOUL 171 
 
 ARTICLE VII 
 
 Brief explanation of the parts of the body and of some of Us 
 functions. 1 
 
 In order to render this more intelligible, I will explain here 
 in a few words how the entire mechanism of our body is com- 
 posed. There is no one who does not already know that there 
 is in us a heart, a brain, a stomach, muscles, nerves, arteries, 
 veins, and such things; it is known also that the food we eat 
 descends into the stomach and the bowels, where their juices 
 flowing through the liver and through all the veins, mix them- 
 selves with the blood they contain, and by this means increase 
 its quantity. Those who have heard the least talk in medicine 
 know, further, how the heart is constructed, and how all the 
 blood of the veins can easily flow through the vena cava on its 
 right side, and thence pass into the lung, by the vessel which is 
 called the arterial vein, then return from the lung on the left 
 side of the heart, by the vessel called the venous artery, and 
 finally pass thence into the great artery, the branches of which 
 are diffused through the whole body. Also, all those whom the 
 authority of the ancients has not entirely blinded, and who are 
 willing to open their eyes to examine the opinion of Hervseus 2 
 in regard to the circulation of the blood, have no doubt what- 
 ever that all the veins and arteries of the body are merely chan- 
 nels through which the blood flows without cessation and very 
 rapidly, starting from the right cavity of the heart by the arte- 
 rial vein, the branches of which are dispersed throughout the 
 lungs and joined to that of the venous artery, by which it passes 
 from the lungs into the left side of the heart; next, from thence 
 it passes into the great artery, the branches of which, scattered 
 throughout all the rest of the body, are joined to the branches of 
 the vein, which carry once more the same blood into the right 
 cavity of the heart; so that these two cavities are like sluices, 
 through each of which all the blood passes every time it makes 
 the circuit of the body. Still further, it is known that all the 
 
 1 Cf. Discourse on Method, pt. v.; Veitch, p. 46; (CEuvres, t. i, p. 173). 
 
 2 Harvey. See tribute to Harvey ((Euvres, t. ix, p. 361).
 
 172 RENE DESCARTES 
 
 movements of the limbs depend upon the muscles, and that 
 these muscles are opposed to one another in such a way that, 
 when one of them contracts, it draws toward itself the part of 
 the body to which it is attached, which at the same time 
 stretches out the muscle which is opposed to it; then, if it hap- 
 pens, at another time, that this last contracts, it causes the first 
 to lengthen, and draws toward itself the part to which they are 
 attached. Finally, it is known that all these movements of the 
 muscles, as also all the senses, depend upon the nerves, wlych 
 are like minute threads, or small tubes, all of which come from 
 the brain, and contain, like that, a certain subtle air or breath, 
 which is called the animal spirits. 
 
 ARTICLE VIII 
 
 The principle of all these functions. 
 
 But it is not commonly known in what manner these animal 
 spirits and these nerves contribute to the movements of the 
 limbs and to the senses, nor what is the corporeal principle 
 which makes them act; it is for this reason, although I have al- 
 ready touched upon this matter in other writings, 1 I shall not 
 omit to say here briefly, that, as long as we live, there is a con- 
 tinual heat in our heart, which is a kind of fire kept up there by 
 the blood of the veins, and that this fire is the corporeal prin- 
 ciple of the movements of our limbs. . . . 
 
 ARTICLE XVI 
 
 How all the limbs can be moved by the objects of the senses and by 
 the spirits without the aid of the soul. 
 
 Finally, it is to be observed that the machine of our body is so 
 constructed that all the changes which occur in the motion of 
 the spirits may cause them to open certain pores of the brain 
 rather than others, and, reciprocally, that when any one of 
 these pores is opened in the least degree more or less than is 
 usual by the action of the nerves which serve the senses, this 
 changes somewhat the motion of the spirits, and causes them 
 1 On Man; also Discourse on Method, etc.; trans, by Veitch, p. 52.
 
 THE PASSIONS OF THE SOUL 173 
 
 to be conducted into the muscles which serve to move the body 
 in the way in which it is commonly moved on occasion of such 
 action ; so that all the movements which we make without our 
 will contributing thereto (as frequently happens when we 
 breathe, or walk, or eat, and, in fine, perform all those actions 
 which are common to us and the brutes) depend only on the 
 conformation of our limbs and the course which the spirits, 
 excited by the heat of the heart, naturally follow in the brain, 
 in the nerves, and in the muscles, in the same way that the 
 movement of a watch is produced by the force solely of its 
 mainspring and the form of its wheels. . . . 
 
 ARTICLE XXX 
 
 That the soul is united to all parts of the body conjointly. 
 
 But, in order to understand all these things more perfectly, 
 it is necessary to know that the soul is truly joined to the entire 
 body, and that it cannot properly be said to be in any one of its 
 parts to the exclusion of the rest, because the body is one, and in 
 a manner indivisible, on account of the arrangement of its or- 
 gans, which are so related to one another, that when any one 
 of them is taken away, that makes the whole body defective: 
 and because the soul is of a nature which has no relation to ex- 
 tension, or to dimensions, or other properties of the matter of 
 which the body is composed, but solely to the whole collection 
 of its organs, as appears from the fact that we cannot at all 
 conceive of the half or the third of a soul, nor what space it 
 occupies, and that it does not become any smaller when any 
 part of the body is cut off, but that it separates itself entirely 
 from it when the combination of its organs is broken up. 
 
 ARTICLE XXXI 
 
 That there is a small gland in the brain in which the soul 
 exercises its functions more particularly than in the other 
 parts. 
 
 It is, also, necessary to know that, although the soul is joined 
 to the entire body, there is, nevertheless, a certain part of the
 
 174 RENE DESCARTES 
 
 body in which it exercises its functions more particularly than 
 in all the rest; and it is commonly thought that this part is the 
 brain, or, perhaps, the heart: the brain, because to it the organs 
 of sense are related ; and the heart, because it is as if there the 
 passions are felt. But, after careful examination, it seems to me 
 quite evident that the part of the body in which the soul im- 
 mediately exercises its functions is neither the heart, nor even 
 the brain as a whole, but solely the most interior part of it, 
 which is a certain very small gland, situated in the middle of its 
 substance, and so suspended above the passage by which the 
 spirits of its anterior cavities communicate with those of the 
 posterior, that the slightest motions in it may greatly affect the 
 course of these spirits, and, reciprocally, that the slightest 
 changes which take place in the course of the spirits may 
 greatly affect the motions of this gland. 
 
 ARTICLE XXXII 
 
 How this gland is known to be the principal seat of the soul. 
 
 The reason which convinces me that the soul cannot have in 
 the whole body any other place than this gland where it exer- 
 cises its functions immediately, is the consideration that the 
 other parts of our brain are all double, just as also we have two 
 eyes, two hands, two ears, and, in fine, all the organs of our 
 external senses are double; and inasmuch as we have but one 
 single and simple thought of the same thing at the same time, 
 there must necessarily be some place where the two images 
 which by means of the two eyes, or the two other impressions 
 which come from a single object by means of the double organs 
 of the other senses, may unite in one before they reach the 
 mind, in order that they may not present to it two objects in 
 place of one; and it may easily be conceived that these images 
 or other impressions unite in this gland, through the medium 
 of the spirits which fill the cavities of the brain; but there 
 is no other place whatever in the whole body, where they can 
 thus be united, except as they have first been united in this 
 gland.
 
 THE PASSIONS OF THE SOUL 175 
 
 Letter to Mersenne, July 30, 1640 * 
 
 As for the letter of the physician De Sens, it contains no argu- 
 ment to impugn what I have written upon the gland called 
 conarium, except that he says that it can be changed like all the 
 brain, which does not at all prevent its being the principal seat 
 of the soul ; for it is certain that the soul must be joined to some 
 part of the body, and there is no point which is not as much or 
 more liable to alteration than this gland, which, although it is 
 very small and very soft, nevertheless, on account of its situa- 
 tion, is so well protected, that it can be almost as little subject 
 to any disease as the crystalline humor of the eye ; and it hap- 
 pens more frequently indeed that persons become troubled in 
 mind, without any known cause, in which case it may be assigned 
 to some disorder of this gland, than it happens that sight fails 
 by any defect of this crystalline humor, besides that all the 
 other changes which happen to the mind, as when one falls asleep 
 after drinking, etc., may be ascribed to some changes occurring 
 in this gland. 
 
 As for what he says about the mind's being able to make use 
 of double organs, I agree with him, and that it makes use also 
 of the spirits, all of which cannot reside in this gland; but I do 
 not at all conceive that the mind is so restricted to it that it 
 cannot extend its activity beyond it; but it is one thing to make 
 use of, and another thing to be immediately joined and united 
 to it; and our mind not being double, but one and indivisible, 
 it seems to me that the part of the body to which it is most 
 immediately united must also be one and not divided into two 
 similar parts, and I find nothing of that kind in the whole brain 
 except this gland. 
 
 ARTICLE XXXIII 
 
 That the seat of the passions is not in the heart. 
 
 As for the opinion of those who think that the soul experi- 
 ences its passions in the heart, it is of no great account, because 
 it is founded only on the fact that .the passions cause some stir 
 1 (Euvres, t. viii, p. 301.
 
 176 RENE DESCARTES 
 
 to be felt there; and it is easy to see that this change is felt, as if 
 in the heart, only through the medium of a small nerve, which 
 descends to it from the brain, just as pain is felt as if in the foot 
 through the medium of the nerves of the foot, and the stars are 
 perceived as in the heavens by the medium of their light and the 
 optic nerves ; so that it is no more necessary that our soul exer- 
 cise its functions immediately in the heart in order to feel there 
 its passions, than it is necessary that it should be in the heavens 
 in order to see the stars there. 
 
 ARTICLE XXXIV 
 
 How the soul and the body act one upon the other. 
 
 Let us conceive, then, that the soul has its principal seat in 
 this little gland in the middle of the brain, whence it radiates 
 to all the rest of the body by means of the spirits, the .nerves, 
 and even of the blood, which, participating in the impressions 
 of the mind, can carry them by means of the arteries into all the 
 members; and, bearing in mind what has been said above con- 
 cerning the machine of our body, to wit, that the minute fila- 
 ments of our nerves are so distributed throughout all its parts 
 that, on occasion of the different motions which are excited there 
 by means of sensible objects, they open in divers manners the 
 pores of the brain, which causes the animal spirits contained in 
 these cavities to enter in various ways into the muscles, by 
 means of which they can move the limbs in all the different ways 
 of which they are capable, and, also, that all the other causes, 
 which in other ways can set the spirits in motion, have the effect 
 to turn them upon various muscles [keeping all this in mind], 
 let us add here that the little gland which is the principal seat 
 of the soul is so suspended between the cavities which contain 
 the spirits, that it can be affected by them in all the different 
 ways that there are sensible differences in objects; but that it 
 can also be variously affected by the soul, which is of such a 
 nature that it receives as many different impressions that is 
 to say, that it has as many different perceptions as there 
 occur different motions in this gland; as also, reciprocally, the
 
 THE PASSIONS OF THE SOUL 177 
 
 machine of the body is so composed that from the simple fact 
 that this gland is variously affected by the soul, or by whatever 
 other cause, it impels the spirits which surround it toward 
 the pores of the brain, which discharge them by means of the 
 nerves upon the muscles, whereby it causes them to move the 
 limbs. . . . 
 
 ARTICLE XL 
 
 The principal effect of the passions. 
 
 It is to be noted that the principal effect of all the passions in 
 man is that they incite and dispose the mind to will the things 
 to which they prepare the body, so that the sentiment of fear 
 incites it to will to fly; that of courage, to will to fight; and so of 
 the rest. 
 
 ARTICLE XLI 
 
 The power of the mind over the body. 
 
 But the will is so free in its nature that it can never be con- 
 strained; and of the two kinds of thoughts which I have dis- 
 tinguished in the mind of which one is its actions, that is, its 
 volitions; the other its passions, taking this word in its most 
 general signification, comprehending all sort of perceptions ' 
 the first of these are absolutely in its power, and can be changed 
 only indirectly by the body, while, on the contrary, the last 
 depend absolutely on the movements which give rise to them, 
 and they can be affected only indirectly by the mind, except 
 when it is itself the cause of them. And the whole action of the 
 mind consists in this, that by the simple fact of its willing any- 
 thing it causes the little gland, to which it is closely joined, to 
 produce the result appropriate to the volition. 
 
 ARTICLE XLII 
 
 How the things we wish to recall are found in the memory. 
 
 Thus, when the mind wills to recall anything, this volition 
 causes the gland, by inclining successively to different sides, to 
 impel the spirits toward different parts of the brain until they
 
 178 RENE DESCARTES 
 
 come upon that where the traces are left of the thing it wills to 
 remember; for these traces are due to nothing else than the 
 circumstance that the pores of the brain, through which the 
 spirits have already taken their course, on presentation of that 
 object, have thereby acquired a greater facility than the rest 
 to be opened again in the same way by the spirits which come 
 to them; so that these spirits coming upon these pores, enter 
 therein more readily than into the others, by which means they 
 excite a particular motion in the gland, which represents to the 
 mind the same object, and causes it to recognize that it is that 
 which it willed to remember. 
 
 ARTICLE XLIII 
 
 How the mind can imagine, attend, and move the body. 
 
 Thus, when it is desired to imagine something which has 
 never been seen, the will has the power to cause the gland to 
 move in the manner requisite to impel the spirits toward the 
 pores of the brain by the opening of which that thing can be 
 represented; so, when one wills to keep his attention fixed for 
 some time upon the same object, this volition keeps the gland 
 inclined during that time in the same direction ; so, finally, when 
 one wills to walk or to move his body in any way, this volition 
 causes the gland to impel the spirits toward the muscles which 
 serve that purpose. 
 
 ARTICLE XLIV 
 
 That each volition is naturally connected with some motion of 
 the gland, but that, by intention or by habit, the will may be con- 
 nected with others. 
 
 Nevertheless, it is not always the volition to excite within us 
 a certain motion, or other effect, which is the cause of its being 
 excited; but this varies according as nature or habit has vari- 
 ously united each motion of the gland to each thought. Thus, 
 for example, if one desires to adjust his eyes to look at a very 
 distant object, this volition causes the pupil of the eye to ex- 
 pand, and if he desires to adjust them so as to see an object very
 
 THE PASSIONS OF THE SOUL 179 
 
 near, this volition makes it contract; but if he simply thinks of 
 expanding the pupil, he wills in vain the pupil will not ex- 
 pand for that, inasmuch as nature had not connected the mo- 
 tion of the gland, which serves to impel the spirits toward the 
 optic nerve in the manner requisite for expanding or contract- 
 ing the pupil, with the volition to expand or contract, but with 
 that of looking at objects distant or near. And when, in talking, 
 we think only of the meaning of what we wish to say, that 
 makes us move the tongue and lips much more rapidly and 
 better than if we thought to move them in all ways requisite 
 for the utterance of the same words, inasmuch as the habit we 
 have acquired in learning to talk has made us join the action of 
 the mind which, through the medium of the gland, can 
 move the tongue and the lips with the meaning of the words 
 which follow these motions rather than with the motions them- 
 selves. . . . 
 
 ARTICLE XL VII 
 
 Wherein consist the conflicts which are imagined to exist between 
 the inferior and the superior parts of the soul. 
 
 It is only in the opposition between the motions that the body 
 through the spirits, and the soul through the will, tend to excite 
 at the same time in the gland, that all the conflicts consist which 
 are commonly imagined to arise between the inferior part of the 
 soul, which is called sensitive, and the superior part, which is 
 rational, or rather between the natural appetites and the will; 
 for there is but one soul within us, and that soul has in it no 
 diversity of parts whatever; the same which is sensitive is ra- 
 tional, and all its appetites are volitions. The error which is 
 committed in making it play the parts of different persons com- 
 monly opposed to each other arises only from the want of a 
 right distinction of its functions from those of the body, to 
 which is to be attributed all that which may be observed within 
 us to be hostile to our reason, so that there is in this no other 
 conflict whatever, except that the little gland which is in the 
 middle of the brain may be pushed on the one side by the soul
 
 i8o RENE DESCARTES 
 
 and on the other by the animal spirits, which are only corporeal, 
 as I have said above, and it often happens that these two im- 
 pulses are contrary, and the stronger hinders the effect of the 
 other. Now there may be distinguished two kinds of motion 
 excited by the spirits in the gland; the one represents to the soul 
 the objects which move the senses, or the impressions which 
 meet in the brain, and produce no effect upon the will ; the other 
 kind is those which produce some effect upon it, namely, those 
 which cause the passions or the movements of the body which 
 accompany them; and as for the first, although they often 
 hinder the actions of the soul, or perhaps may be hindered by 
 them, nevertheless, because they are not directly opposed, no 
 conflict is observed. . . . 
 
 PART II 
 
 ARTICLE LI 
 
 The primary causes of the passions. 
 
 IT is understood, from what has been said above, that the 
 last and proximate cause of the passions of the soul is nothing 
 but the motion imparted by the spirits to the little gland in the 
 middle of the brain. But this is not enough to enable us to dis- 
 tinguish them from one another; it is necessary to trace them 
 to their sources and to inquire into their primary causes; now, 
 although they may sometimes be caused by the action of the 
 mind, which determines to think upon such or such objects, 
 and also by the mere bodily temperament or by the impressions 
 which happen to present themselves in the brain, as occurs when 
 one feels sad or joyous without being able to assign any reason 
 for it, it should appear, nevertheless, according to what has been 
 said, that the same passions may all be excited by objects which 
 move the senses, and that these objects are their most ordinary 
 and principal causes; whence it follows that, to discover 
 them all, it is sufficient to consider all the effects of these 
 objects.
 
 THE PASSIONS OF THE SOUL 181 
 
 ARTICLE LII 
 
 What service they render, and how their number may be deter- 
 mined. 
 
 I observe, further, that the objects which move the senses do 
 not excite in us different passions by reason of all the diversities 
 which are in them, but solely on account of the different ways 
 in which they can injure or profit us, or, in general, be import- 
 ant to us; and that the service which all the passions render 
 consists in this alone, that they dispose the mind to choose the 
 things which nature teaches us are useful, and to persist in this 
 choice, while also the same motion of the spirits which com- 
 monly causes them disposes the body to the movements which 
 serve to the performance of those things; this is why, in order to 
 determine the number of the passions, it is necessary merely to 
 inquire, in due order, how many different ways important to 
 us there are in which our senses can be moved by their objects ; 
 and I shall here make the enumeration of all the principal pas- 
 sions in the order in which they may thus be found. 
 
 ARTICLE LIII 
 
 Wonder. 
 
 When on first meeting an object we are surprised, and judge 
 it to be novel, or very different from what we knew it before, or 
 from what we supposed it should be, this causes us to wonder at 
 it and be astonished ; and since this may happen before we could 
 know whether this object was beneficial to us or not, it seems 
 to me that wonder is the first of all the passions; and it has no 
 contrary, because, if the object which presents itself has no- 
 thing in it which surprises us, we are not at all moved by it, 
 and we regard it without emotion. 
 
 ARTICLE LXVIII 
 
 Why this enumeration of the passions differs from that com- 
 monly received. 
 
 Such is the order which seems to me the best in enumerating 
 the passions. I know very well that in this my position is differ-
 
 1 82 RENE DESCARTES 
 
 ent from that of all who have hitherto written upon them, but 
 it is so not without important reason. For they derive their 
 enumeration from their distinction in the sensitive part of the 
 soul of two appetites, one of which they call concupiscible, the 
 other irascible.*- And, inasmuch as I recognize in the soul no 
 distinction of parts, as I have said above, this seems to me to 
 signify nothing else but that it has two faculties : one of desiring, 
 the other of being angry; and because it has in the same way 
 the faculties of admiring, of loving, of hoping, of fearing, and of 
 entertaining each of the other passions, or of performing the 
 actions to which these passions incline it, I do not see why they 
 have chosen to refer all to desire or to anger. Moreover, their 
 enumeration does not include all the principal passions, as I 
 believe this does. I speak only of the principal ones, because 
 there may still be distinguished many other more special ones, 
 and their number is indefinite. 
 
 ARTICLE LXIX 
 
 That there are only six primary passions. 
 
 But the number of those which are simple and primary is not 
 very great. For, on reviewing all those which I have enumer- 
 ated, it is readily observed that there are only six of this sort; to 
 wit, wonder, love, hate, desire, joy, and sadness, and that all 
 fie rest are made up of some of these six, or at least are species 
 of them. This is why, in order that their number may not em- 
 barrass my readers, I shall here treat separately of the six 
 primaries; and afterward I shall show how all the rest derive 
 their origin from these. 
 
 ARTICLE LXXIV 
 
 In what respect the passions are of service and in what they are 
 harmful. 
 
 Now it is easy to see, from what has been said above, that the 
 usefulness of all the passions consists only in this, that they 
 strengthen and make enduring in the mind the thoughts which 
 1 Plato, Republic, bk. iv.
 
 THE PASSIONS OF THE SOUL 183 
 
 it is well for it to keep, and which but for that might easily be 
 effaced from it. As, also, all the evil they can cause consists in 
 their strengthening and preserving those thoughts in the mind 
 more than there is any need of, or else that they strengthen and 
 preserve others which it is not well for the mind to attend to. 
 
 ARTICLE LXXIX 
 
 Definitions of love and hatred. 
 
 Love is an emotion of the soul, caused by the motion of the 
 spirits, which incites it to unite itself voluntarily to those ob- 
 jects which appear to it to be agreeable. And hatred is an emo- 
 tion, caused by the spirits, which incites the mind to will to be 
 separated from objects which present themselves to it as harm- 
 ful. I say that these emotions are caused by the spirits, in order 
 to distinguish love and hatred, which are passions, and depend 
 upon the body, as well as the judgments which also incline the 
 mind to unite itself voluntarily with the things which it regards 
 as good, and to separate itself from those which it regards as 
 evil, as the emotions which these judgments excite in the soul. 
 
 ARTICLE LXXX 
 
 What is meant by voluntary union and separation. 
 
 For the rest, by the word voluntarily, I do not here intend 
 desire, which is a passion by itself, and relates to the future, but 
 the consent wherein one considers himself for the moment as 
 united with the beloved object, conceiving as it were of one 
 whole of which he thinks himself but one part, and the object 
 beloved the other. While on the contrary, in the case of hatred, 
 one considers himself alone as a whole, entirely separated from 
 the object for which he has aversion. 
 
 ARTICLE LXXXVI 
 Definition of desire. 
 
 The passion of desire is an agitation of the soul, caused by the 
 spirits, which disposes it to wish for the future the objects which
 
 184 RENE DESCARTES 
 
 it represents to itself to be agreeable. Thus one desires not only 
 the presence of absent good, but also the preservation of the 
 present good, and, in addition, the absence of evil, as well that 
 which is already experienced as that which it is feared the 
 future may bring. 
 
 ARTICLE XCI 
 
 Definition of joy. 
 
 Joy is an agreeable emotion of the soul in which consists 
 the enjoyment that it has in any good which the impressions of 
 the brain represent to it as its own. I say that it is in this emo- 
 tion that the enjoyment of good consists, for in reality the soul 
 receives no other fruit of all the goods it possesses; and so long 
 as it has no joy in them, it may be said that it has no more frui- 
 tion of them than if it did not possess them at all. I add, also, 
 that it is of good which the impressions of the brain represent 
 to it as its own, in order not to confound this joy, which is a 
 passion, with the purely intellectual joy, which arises in the 
 mind by the simple activity of the mind, and which may be 
 said to be an agreeable emotion excited within itself, in which 
 consists the enjoyment which it has of the good which its 
 understanding represents to it as it own. It is true that, so 
 long as the mind is joined to the body, this intellectual joy can 
 scarcely fail to be accompanied with that joy which is passion ; 
 for, as soon as our understanding perceives that we possess 
 any good, although that good may be as different as imagin- 
 able from all that pertains to the body, the imagination does 
 not fail on the instant to make an impression on the brain, 
 upon which follows the motion of the spirits which excites the 
 passion of joy. 
 
 ARTICLE XCII 
 
 Definition of sadness. 
 
 Sadness is a disagreeable languor, in which consists the dis- 
 tress which the mind experiences from the evil or the defect 
 which the impressions of the brain represent as pertaining to it. 
 And there is also an intellectual sadness, which is not the 
 passion, but which seldom fails to be accompanied by it.
 
 THE PASSIONS OF THE SOUL 185 
 
 ARTICLE XCVI 
 
 The motions of the blood and the spirits which cause these five 
 passions. 
 
 The five passions which I have here begun to explain are so 
 joined or opposed to one another, that it is easier to consider 
 them all together than to treat of each separately (as wonder 
 has been treated) ; and the cause of them is not as is the case 
 with wonder, in the brain alone, but also in the heart, the spleen, 
 the liver, and in all other parts of the body, in so far as they 
 serve in the production of the blood, and thereby of the spirits ; 
 for although all the veins conduct the blood they contain toward 
 the heart, it happens, nevertheless, that sometimes the blood in 
 some of them is impelled thither with more force than that in 
 others; it happens, also, that the openings by which it enters 
 into the heart, or else those by which it passes out, are more 
 enlarged or more contracted at one time than at another. . . . 
 
 ARTICLE CXXXVII 
 
 Of the utility of these five passions here explained, in so far as 
 they relate to the body. 
 
 Having given the definitions of love, of hatred, of desire, of 
 joy, of sadness (and treated of all the corporeal movements 
 which cause or accompany them 1 ) we have only to consider 
 here their utility. In regard to which it is to be noted that, 
 according to the appointment of nature, they all relate to the 
 body, and are bestowed upon the mind only in so far as it is 
 connected with it; so that their natural use is to incite the mind 
 to consent and contribute to the actions which may aid in the 
 preservation of the body, or render it in any way more perfect; 
 and, in this sense, sadness and joy are the first two which are 
 employed. For the mind is immediately warned of the things 
 which harm the body only through the sensation of pain, which 
 produces in it first the passion of sadness; next, hatred of that 
 which causes this pain; and thirdly, the desire to be delivered 
 
 1 In the intervening Articles.
 
 i86 RENE DESCARTES 
 
 from it; likewise the mind is made aware immediately of things 
 useful to the body only by some sort of pleasure, which excites 
 in it joy, then gives birth to love of that which is believed to be 
 the cause of it, and, finally, the desire to acquire that which can 
 make the joy continue, or else that the like may be enjoyed 
 again. Whence it is apparent that these five passions are all 
 very useful as regards the body, and also that sadness is, in a 
 certain way, first and more necessary than joy, and hatred than 
 love, because it is more important to repel things which harm 
 and may destroy us, than to acquire those which add a per- 
 fection without which we can still subsist. . . . 
 
 ARTICLE CXLIV 
 
 Of desires where the issue depends only on ourselves. 
 
 But because the passions can impel us to action only through 
 the medium of the desire which we must take pains to regulate 
 and in this consists the principal use of morality; now, as I 
 have just said, as it is always good when it follows a true know- 
 ledge, so it cannot fail to be bad when it is based on error. And 
 it seems to me that the erijor most commonly committed in 
 regard to desires is the failure to distinguish sufficiently the 
 things which depend entirely upon ourselves and those which 
 do not; for, as for those which depend only upon ourselves, that 
 is to say, upon our free will, it is sufficient to know that they are 
 good to make it impossible for us to desire them with too great 
 ardor, since to do the good things which depend upon ourselves 
 is to follow virtue, and it is certain that one cannot have too 
 ardent a desire for virtue, and moreover, it being impossible 
 for us to fail of success in what we desire in this way, since it 
 depends on ourselves alone, we shall always attain all the satis- 
 faction that we have expected. But the most common fault 
 in this matter is not that too much, but too little, is desired; 
 and the sovereign remedy against that is to deliver the mind as 
 much as possible from all other less useful desires, then to try 
 to understand very clearly, and to consider attentively, the 
 excellence of that which is to be desired.
 
 THE PASSIONS OF THE SOUL 187 
 
 \ 
 
 ARTICLE CXLV 
 
 Of those which depend only on other things. 
 
 As for the things which depend in no wise upon ourselves, 
 however good they may be, they should never be desired with 
 passion; not only because they may not come to pass, and in 
 that case we should be so much the more cast down, as we have 
 the more desired them, but principally because by occupying 
 our thoughts they divert our interest from other things the 
 acquisition of which depends upon ourselves. And there are 
 two general remedies for these vain desires; the first is high- 
 mindedness (la generosite), of which I shall speak presently; the 
 second is frequent meditation on Divine Providence, with the 
 reflection that it is impossible that anything should happen in 
 any other manner than has been determined from all eternity 
 by this Providence ; so that it is like a destiny or an immutable 
 necessity, which is to be contrasted with chance in order to 
 destroy it as a chimera arising only from an error of our under- 
 standing. For we can desire only those things which we regard 
 as being in some way possible, and we do not regard as possible 
 things which do not at all depend upon ourselves, except in so 
 far as we think that they depend on chance, that is to say, as we 
 judge that they can happen, and that similar things have hap- 
 pened before. Now this opinion is based only on the fact that 
 we do not know all the causes which have contributed to each 
 effect; for when anything which we have thought depended 
 upon chance has not taken place, this shows that some one of 
 the causes necessary to produce it was wanting, and, conse- 
 quently, that it was absolutely impossible, and the like of it 
 never took place; that is to say, to the production of the like a 
 similar cause was also wanting, so that, had we not been igno- 
 rant of that beforehand, we never should have thought it pos- 
 sible, and consequently should not have desired it. 
 
 ARTICLE CXLVI 
 
 Of those things which depend upon ourselves and others. 
 
 It is necessary then utterly to reject the common opinion
 
 188 RENE DESCARTES 
 
 that there is externally to ourselves a chance which causes 
 things to happen or not to happen, at its pleasure, and to know, 
 on the other hand, that everything is guided by Divine Provi- 
 dence, whose eternal decree is so infallible and immutable, that, 
 excepting the things which the same decree has willed to depend 
 upon our free choice, we must think that in regard to us nothing 
 happens which is not necessary, and, as it were, destined, so that 
 we cannot, without folly, wish it to happen otherwise. But 
 because most of our desires extend to things, all of which do not 
 depend upon ourselves, nor all of them upon others, we should 
 distinguish precisely that in them which depends only on our- 
 selves in order to confine our desires to that; and, moreover, 
 although we should consider success therein to be altogether a 
 matter of immutable destiny, in order that our desires may not 
 be taken up with it, we ought not to fail to consider the reasons 
 which make it more or less to be hoped for, to the end that they 
 may serve to regulate our conduct ; as, for example, if we had 
 business in a certain place to which we might go by two different 
 roads, one of which was ordinarily much safer than the other, 
 although perhaps the decree of Providence was such that if 
 we went by the road considered safest we should certainly be 
 robbed, and that, on the contrary, we might travel the other 
 with no danger at all, we ought not on that account to be indif- 
 ferent in choosing between them, nor rest on the immutable 
 destiny of that decree; but reason would have it that we should 
 choose the road which was ordinarily considered the safer, and 
 our desire should be satisfied regarding that when we have fol- 
 lowed it, whatever be the evil that happens to us, because that 
 evil, being as regards ourselves inevitable, we have had no rea- 
 son to desire to be exempt from it, but simply to do the very 
 best that our understanding is able to discover, as I assume we 
 have done. And it is certain that when one thus makes a prac- 
 tice of distinguishing destiny from chance, he easily accustoms 
 himself so to regulate his desires that, in so far as their accom- 
 plishment depends only upon himself, they may always afford 
 him entire satisfaction.
 
 THE PASSIONS OF THE SOUL 189 
 
 ARTICLE CXLVII 
 
 Of the interior emotions of the mind. 
 
 I will simply add a consideration which appears to me of 
 much service in averting from us the disturbance of the pas- 
 sions : it is that our good and our evil principally depend upon 
 the interior emotions, which are excited in the mind only by the 
 mind itself, in which respect they differ from its passions, which 
 always depend upon some motion of the spirits; and although 
 these emotions of the mind are often united with the passions 
 which resemble them, they may often also agree with others, 
 and even arise from those which are contrary to them. . . . 
 And when we read of strange adventures in a book, or see them 
 represented on the stage, this excites in us sometimes sadness, 
 sometimes joy, or love, or hatred, and, in general, all the pas- 
 sions, according to the diversity of the objects which present 
 themselves to our imagination ; but along with that we have 
 the pleasure of feeling them excited within us, and this pleasure 
 is an intellectual joy, which can arise from sadness as well as 
 from any other passion. 1 
 
 ARTICLE CXLVIII 
 
 That the practice of virtue is a sovereign remedy for all the 
 passions. 
 
 Now, inasmuch as these interior emotions touch us more 
 nearly, and in consequence have much greater power over us 
 than the passions from which they differ, which occur with them, 
 it is certain that, provided the mind have that within wherewith 
 it may be content, all the troubles which come from elsewhere 
 have no power whatever to disturb it, but rather serve to aug- 
 ment its joy, in that, seeing that it cannot be troubled by them, 
 it is thereby made aware of its own superiority. And to the end 
 that the mind may have that wherewith to be content, it needs 
 but to follow virtue perfectly. For whoever has lived in such a 
 manner that his conscience cannot reproach him with ever 
 
 1 Cf. Aristotle, Poetics, 6.
 
 190 RENE DESCARTES 
 
 having failed to do any of those things which he has judged to 
 be the best (which is what I call here following virtue), he en- 
 joys a satisfaction so potent in ministering to his happiness, 
 that the most violent efforts of the passions never have power 
 enough to disturb the tranquillity of his mind.
 
 BARUGH DE SPINOZA 
 
 (1632-1677) 
 
 THE ETHICS 
 
 Translated from the Latin* by 
 GEORGE STUART FULLERTON 
 
 PART II. OF THE NATURE AND ORIGIN OF 
 THE MIND 
 
 I NOW proceed to set forth those things that necessarily had 
 to follow from the essence of God, a Being eternal and infinite. 
 
 1 shall not, indeed, treat of all of them, for I have shown (I, 16) 
 that there must follow from this essence an infinity of things in 
 infinite ways, but I shall treat only of those which may lead us, 
 as it were, by the hand, to a knowledge of the human mind and 
 its highest blessedness. 
 
 Definitions 
 
 1. By body I mean a mode which expresses, in a definite and 
 determinate manner, the essence of God, in so far as he is con- 
 sidered as an extended thing. (See I, 25, cor.} 
 
 2. I regard as belonging to the essence of a thing that which, 
 being given, the thing is necessarily given, and which being 
 taken away, the thing is necessarily taken away ; in other words, 
 that without which the thing, and, conversely, which without 
 the thing, can neither be nor be conceived. 
 
 3. By idea I mean a conception of the mind, which the mind 
 forms because it is a thinking thing. 
 
 * Opera posthuma, Amsterdam, 1677; Opera, rec. J.Van Vloten et J. P. Land. 
 Hagae Comitum, 1882-83; ed. altera, ib., 1895-6, torn. i. Reprinted here from 
 The Philosophy of Spinoza, translated and edited by George Stuart Fullerton, 
 
 2 enl. ed. New York, Henry Holt and Company, 1894.
 
 192 BARUCH DE SPINOZA 
 
 Explanation. I say rather conception than perception, be- 
 cause the word perception seems to indicate that the mind is 
 acted upon by the object; but conception seems to express an 
 action of the mind. 
 
 4. By adequate idea I mean an idea which, in so far as it is 
 considered in itself and without reference to an object, possesses 
 all the properties or intrinsic marks of a true idea. 
 
 Explanation. I say intrinsic, to exclude the extrinsic mark, 
 namely, the agreement of the idea with its object. 
 
 5. Duration is indefinite continuance in existence. 
 Explanation. I say indefinite, because it can in no wise be 
 
 limited by the nature itself of the existing thing, nor yet by the 
 efficient cause, which, to be sure, necessarily brings about the 
 existence of the thing, but does not sublate it. 
 
 6. By reality and perfection I mean the same thing. 
 
 7. By individual things I mean things that are finite and have 
 a determinate existence. If, however, several individuals so 
 unite in one action that all are" conjointly the cause of the one 
 effect, I consider all these, in so far, as one individual thing. 
 
 Axioms 
 
 1. Man's essence does not involve necessary existence; in 
 other words, in the order of nature, it equally well may or may 
 not come to pass that this or that man exists. 
 
 2. Man thinks. 
 
 3. Such modes of thinking as love, desire, or whatever else 
 comes under the head of emotion, do not arise unless there be 
 present in the same individual the idea of the thing loved, 
 desired, etc. But the idea may be present without any other 
 mode of thinking being present. 
 
 4. We perceive by sense that a certain body is affected in 
 many ways. 
 
 5. We do not feel or perceive any individual things except 
 bodies and modes of thinking. 
 
 PROP. i. Thought is an attribute of God, that is, God is a think- 
 ing thing.
 
 THE ETHICS 193 
 
 Proof. Individual thoughts, or this and that thought, are 
 modes which express in a definite and determinate manner 
 God's nature (I, 25, cor.}. God therefore possesses (I, def. 5) 
 the attribute, the conception of which is involved in all indi- 
 vidual thoughts, and through which they are conceived. Hence, 
 thought is one of the infinite attributes of God, and it expresses 
 God's eternal and infinite essence (I, def. 6) : that is, God is a 
 thinking thing. Q. E. D. 
 
 Scholium. This proposition 'may also be proved from the 
 fact that we can conceive an infinite thinking being. For the 
 more thoughts a thinking being is capable of having, the more 
 reality or perfection do we regard it as containing; a being, 
 then, that can think an infinity of things in an infinity of ways 
 is necessarily, by virtue of its thinking, infinite. Since, there- 
 fore, we conceive an infinite being by fixing attention upon 
 thought alone, thought is necessarily (I, defs. 4 and 6) one of the 
 infinite attributes of God, as I asserted. 
 
 PROP. 2. Extension is an attribute of God, that is, God is an 
 extended thing. 
 
 Proof. This is proved like the preceding proposition. 
 
 PROP. 3. There is necessarily in God an idea, both of his own 
 essence, and of all those things which necessarily follow from his 
 essence. 
 
 Proof. God can (i) think an infinity of things in an infinity 
 of ways, or (which is the same thing, I, 16) can form an idea of 
 his own essence, and of all those things which necessarily follow 
 from it. But everything that is within God's power necessarily 
 is (I, 35). Therefore such an idea necessarily is, and (1, 15) it is 
 in God and nowhere else. Q. E. D. 
 
 PROP. 6. The modes of any attribute have God as their cause, 
 only in so far as he is considered under the attribute of which they 
 are modes, not in so far as he is considered under any other attri- 
 bute. 
 
 Proof. Each attribute is conceived through itself independ- 
 ently of anything else (I, 10). The modes, then, of each attri- 
 bute involve the concept of their own attribute, but of no other; 
 therefore (I, axiom 4), they have as their cause God, only in so
 
 194 BARUCH DE SPINOZA 
 
 far as he is considered under the attribute of which they are 
 modes, and not in so far as he is considered under any other 
 attribute. Q. E. D. 
 
 Corollary. Hence it follows that the formal being of things, 
 which are not modes of thinking, does not follow from the divine 
 nature because this first knew things; but the objects of ideas 
 follow and are inferred from their attributes in the same manner, 
 and by the same necessity, as we have shown ideas to follow 
 from the attribute of thought. 
 
 PROP. 7. The order and connection of ideas is the same as the 
 order and connection of things. 
 
 Proof. The proof is evident from axiom 4, of Part I, for the 
 idea of anything that is caused depends upon a knowledge of the 
 cause whose effect it is. 
 
 Corollary. Hence it follows that God's power of thinking 
 is equal to his realized power of acting. That is, whatever fol- 
 lows formally from God's infinite nature follows also objectively 
 in God in the same order and with the same connection from 
 the idea of God. 
 
 Scholium. Before going further we should recall to mind 
 this truth, which has been proved above, namely, that whatever 
 can be perceived by infinite intellect as constituting the essence 
 of substance belongs exclusively to the one substance, and con- 
 sequently that thinking substance and extended substance are 
 one and the same substance, apprehended now under this, now 
 under that attribute. So, also, a mode of extension and the idea 
 of that mode are one and the same thing, but expressed in two 
 ways; a truth which certain of the Hebrews appear to have seen 
 as if through a mist, in that they assert that God; the intellect 
 of God, and the things known by it, are one and the same. For 
 example, a circle existing in nature, and the idea, which also is 
 in God, of this existing circle, are one and the same thing, mani- 
 fested through different attributes; for this reason, whether we 
 conceive nature under the attribute of extension, or under that 
 of thought, or under any other attribute whatever, we shall find 
 there follows one and the same order, or one and the same con- 
 catenation of causes, that is, the same thing. I have said that
 
 THE ETHICS 195 
 
 God is the cause of an idea; for instance, the idea of a circle, 
 merely in so far as he is a thinking thing, and of the circle, 
 merely in so far as he is an extended thing, just for the reason 
 that the formal being of the idea of a circle can only be per- 
 ceived through another mode of thinking, as its proximate 
 cause, that one in its turn through another, and so to infinity. 
 Thus, whenever we consider things as modes of thinking, we 
 must explain the whole order of nature, or concatenation of 
 causes, through the attribute of thought alone; and in so far 
 as we consider them as modes of extension, we must likewise 
 explain the whole order of nature solely through the attribute of 
 extension. So also in the case of the other attributes. Hence 
 God, since he consists of an infinity of attributes, is really the 
 cause of things as they are in themselves. I cannot explain this 
 more clearly at present. 
 
 PROP. 8. The ideas of individual things or modes which do not 
 exist must be comprehended in the infinite idea of God, in the same 
 way as the formal essences of individual things or modes are con- 
 tained in the attributes of God. 
 
 Proof. This proposition is evident from the one preceding, 
 but it may be more clearly understood from the preceding 
 scholium. 
 
 Corollary. Hence it follows that so long as individual things 
 do not exist, except in so far as they are comprehended in the 
 attributes of God, their objective being, that is, their ideas, do 
 not exist, except in so far as the infinite idea of God exists; and 
 when particular things are said to exist, not merely in so far as 
 they are comprehended in the attributes of God, but also in so 
 far as they are said to have a being in time, their ideas, too, 
 involve an existence, through which they are said to have a 
 being in time. 
 
 PROP. 10. Substantive being does not belong to the essence 
 of man, that is, substance does not constitute the essence of 
 man. 
 
 Proof. Substantive being involves necessary existence 
 (I, 7) . If, then, substantive being belongs to the essence of man, 
 granted substance, man would necessarily be granted (def. 2) :
 
 196 BARUCH DE SPINOZA 
 
 hence man would necessarily exist, which (axiom i) is absurd. 
 Therefore, etc. Q. E. D. 
 
 Scholium. This proposition is proved also by I, 5, which 
 maintains that there are not two substances of the same nature. 
 As, however, a number of men may exist, that which consti- 
 tutes the essence of man is not substantive being. This pro- 
 position is evident, moreover, from the other properties of 
 substance, to wit, that substance is in its nature infinite, 
 immutable, indivisible, etc.; as anyone may readily see. 
 
 Corollary. Hence it follows that the essence of man con- 
 sists of certain modifications of God's attributes. Substantive 
 being (by the preceding proposition) does not belong to the es- 
 sence of man. It is, therefore (1, 15), something which is in God, 
 and which without God can neither be nor be conceived, that is 
 (I, 25, cor.), a modification, or mode, which expresses God's 
 nature in a definite and determinate manner. 
 
 PROP. ii. The first thing that constitutes the actual being of the 
 human mind is nothing else than the idea of some individual thing 
 actually existing. 
 
 Proof. Man's essence (by the corollary to the preceding propo- 
 sition) consists of certain modes of the attributes of God; 
 namely (axiom 2) of modes of thinking, in all of which (axiom 3) 
 an idea is prior by nature, and when this is present the other 
 modes (those, that is, to which the idea is prior by nature) 
 must be present in the same individual (by the same axiom). 
 Thus an idea is the first thing that constitutes the being of the 
 human mind. But it is not the idea of a non-existent thing, for 
 in that case (8, cor.) the idea itself could not be said to exist; it 
 is, then, the idea of a thing actually existing. Not, however, of 
 an infinite thing. For an infinite thing (I, 21 and 22) must 
 always necessarily exist; but this is (axiom i) absurd; there- 
 fore the first thing that constitutes the actual being of the 
 human mind is the idea of an individual thing actually existing. 
 Q. E. D. 
 
 Corollary. Hence it follows that the human mind is a part 
 of the infinite intellect of God. When, therefore, we say that 
 the human mind perceives this or that, we say merely that God,
 
 THE ETHICS 197 
 
 not in so far as he is infinite, but in so far as he is manifested by 
 the nature of the human mind, that is, in so far as he consti- 
 tutes the essence of the human mind, has this or that idea; and 
 when we say that God has this or that idea, not merely in so far 
 as he constitutes the nature of the human mind, but in so far as 
 besides the human mind he has also the idea of another thing, 
 we say the human mind perceives the thing partially or inade- 
 quately. 
 
 Scholium. Here, doubtless, my readers will stick, and will 
 contrive to find many objections which will cause delay. For 
 this reason I beg them to proceed with me slowly, and not to 
 pass judgment on these matters until they have read over the 
 whole. 
 
 PROP. 12. Whatever takes place in the object of the idea that 
 constitutes the human mind must be perceived by the human mind; 
 that is, an idea of that thing is necessarily in the mind. In other 
 words, if the object of the idea that constitutes the human mind be a 
 body, nothing can take place in that body without being perceived 
 by the mind. 
 
 Proof. Whatever takes place in the object of any idea, the 
 knowledge of it is necessarily in God (9, cor.}, in so far as he is 
 considered as affected by the idea of that object; that is (n), in 
 so far as he constitutes the mind of anything. Whatever, then, 
 takes place in the object of the idea that constitutes the human 
 mind, the knowledge of it is necessarily in God, in so far as he 
 constitutes the nature of the human mind, that is (n, cor.}, the 
 knowledge of it is necessarily in the mind, or the mind perceives 
 it. Q. E. D. 
 
 Scholium. This proposition is evident also, and more 
 clearly understood, from 7, schol., which see. 
 
 PROP .13. The object of the idea that constitutes the human mind 
 is the body, that is, a definite mode of extension actually existing, 
 and nothing else. 
 
 Proof. If the body were not the object of the human mind, 
 the ideas of the modifications of the body would not be in God 
 (9, cor}, in so far as he constituted our mind, but in so far as he 
 constituted the mind of something else; that is (n, cor.}, the
 
 i 9 8 BARUCH DE SPINOZA 
 
 ideas of the modifications of the body would not be in our 
 mind. But (axiom 4) we have ideas of the modifications of the 
 body. Therefore the object of the idea that constitutes the 
 human mind is the body, and that (n) is a body actually exist- 
 ing. Again, if, besides the body, there was still another object 
 of the mind, then, since nothing (I, 36) exists from which some 
 effect does not follow, there would (n) necessarily have to be 
 in our mind the idea of some effect of this object. But (axiom 5) 
 there is no such idea. Therefore the object of our mind is the 
 existing body and nothing else. Q. E. D. 
 
 Corollary. Hence it follows that man consists of mind and 
 body, and that the human body exists, just as we perceive it. 
 
 Scholium. From this we comprehend, not merely that the 
 human mind is united to the body, but also what is meant by 
 the union of mind and body. No one, however, can compre- 
 hend this adequately or distinctly, unless he first gain an ade- 
 quate knowledge of the nature of our body. What I have proved 
 so far have been very general truths, which do not apply more 
 to men than to all other individual things, which are all, though 
 in different degrees, animated. For of everything there is 
 necessarily an idea in God, of which God is the cause, just as 
 there is an idea of the human body ; hence, whatever I have said 
 of the idea of the human body must necessarily be said of the 
 idea of everything. Yet we cannot deny that ideas differ among 
 themselves as do their objects, and that one is more excellent 
 than another, and contains more reality, just as the object of 
 the one is more excellent than the object of the other, and con- 
 tains more reality. Therefore, in order to determine in what the 
 human mind differs from other ideas, and in what it excels the 
 others, we must gain a knowledge, as I have said, of the nature 
 of its object, that is, of the human body. This, however, I can- 
 not here treat of, nor is it necessary for what I wish to prove. 
 I will only make the general statement that, in proportion as 
 any body is more capable than the rest of acting or being acted 
 upon in many ways at the same time, its mind is more capable 
 than the rest of having many perceptions at the same time; 
 and the more the actions of a body depend upon itself alone,
 
 THE ETHICS 199 
 
 and the less other bodies contribute to its action, the more capa- 
 ble'is its mind of distinct comprehension. We may thus discern 
 the superiority of one mind over others, and we may see the 
 reason why we have only a very confused knowledge of our 
 body. . . . 
 
 Postulates 
 
 1. The human body is composed of very many individuals of 
 different natures, each one of which is highly composite. 
 
 2. Of the individuals which compose the human body, some 
 are fluid, some soft, and some hard. 
 
 3. The individuals which compose the human body, and, 
 consequently, the human body itself, are affected in very many 
 ways by external bodies. 
 
 4. The human body needs, for its conservation, very many 
 other bodies, by which it is continually, as it were, born 
 anew. 
 
 5. When a fluid part of the human body is determined by an 
 external body to impinge often upon a soft part, it changes the 
 plane of the latter, and imprints upon it certain traces, as it 
 were, of the impelling external body. 
 
 6. The human body can move external bodies in very many 
 ways, and arrange them in very many ways. 
 
 PROP. 14. The human mind is capable of having very many 
 perceptions, and the more capable, the greater the number of ways 
 in which its body can be disposed. 
 
 Proof. The human body (postulates 3 and 6) is affected in 
 very many ways by external bodies, and is adapted to affect 
 external bodies in very many ways. But (12) the human mind 
 must perceive whatever takes place in the human body. There- 
 fore, the human mind is capable of having very many percep- 
 tions, and the more capable, etc. Q. E. D. 
 
 PROP. 15. The idea, which constitutes the essential being of the 
 human mind, is not simple, but composed of very many ideas. 
 
 Proof. The idea, which constitutes the essential being of 
 the human mind, is the idea of the body (13), and this (postu- 
 late i) is compo
 
 200 BARUCH DE SPINOZA 
 
 there is necessarily in God (8, cor.} an idea of each of the indi- 
 viduals which compose the body. Therefore (7) the idea of the 
 human body is composed of these many ideas of the component 
 parts. Q. E. D. 
 
 PROP. 1 6. The idea of any mode, in which the human body is 
 affected by external bodies, must involve both the nature of the 
 human body and the nature of the external body. 
 
 Proof. All the modes, in which any body is affected, are a 
 consequence both of the nature of the body affected, and the 
 nature of the body affecting it (axiom i, after the cor. to lemma 3). 
 Hence their idea (I, axiom 4) necessarily involves the nature of 
 both bodies. Consequently, the idea of any mode, in which the 
 human body is affected by an external body, involves the nature 
 of the human body and of the external body. Q. E. D. 
 
 Corollary i. Hence it follows, in the first place, that the 
 human mind perceives the nature of very many bodies along 
 with the nature of its own body. 
 
 Corollary 2. And it follows, in the second place, that the 
 ideas which we have of external bodies indicate rather the con- 
 stitution of our own body than the nature of external bodies; 
 as I have explained with many illustrations in the Appendix to 
 Part I. 
 
 PROP. 17. // the human body is affected in a manner which 
 involves the nature of any external body, the human mind will re- 
 gard this external body as actually existing, or as present to it, until 
 the body is affected with some modification which excludes the exist- 
 ence or presence of this body. 
 
 Proof. This is evident. For as long as the human body is 
 thus affected, the human mind (12) will contemplate this modi- 
 fication of the body; in other words (by the preceding proposi- 
 tion}, will have the idea of a mode actually existing, which in- 
 volves the nature of an external body; that is, an idea that does 
 not exclude the existence or presence of the nature of the 
 external body, but affirms it. Therefore the mind (cor. i to the 
 preceding proposition] will regard an external body as actually 
 existing, or as present, until it-is affected, etc. Q. E. D. 
 
 Corollary. The mind can contemplate, as if they were
 
 THE ETHICS 201 
 
 present, external bodies by which the human body has once 
 been affected, although they do not exist and are not present. 
 
 Scholium. Thus we see how it can be that we regard as 
 present things that do not exist, as often happens. It is possible 
 that this is brought about by other causes, but it is here suffi- 
 cient that I have shown one by which I can explain the thing as 
 well as if I had explained it by its true cause. Nevertheless I do 
 not think I am far wrong, since all the postulates I have as- 
 sumed contain scarcely anything not in harmony with expe- 
 rience, and experience we may not doubt, after we have shown 
 that the human body exists just as we perceive it (13, cor.}. 
 Besides (from the preceding cor., and 16, cor. 2) we clearly com- 
 prehend the difference between the idea, for instance, of Peter, 
 which constitutes the essence of the mind of Peter, and the idea 
 of the same Peter, which is in another man, say in Paul. The 
 former directly expresses the essence of Peter's body, nor does 
 it involve existence, except so long as Peter exists; the latter, on 
 the other hand, indicates rather the condition of Paul's body 
 than the nature of Peter; and, therefore, while that condition 
 of Paul's body endures, Paul's mind will regard Peter as present, 
 even if he does not exist. Further, to keep to the usual phrase- 
 ology, we will call the modifications of the human body, the 
 ideas of which represent external bodies as present to us, images 
 of things, although they do not reproduce the shapes of things. 
 When the mind contemplates bodies in this way, we will speak 
 of it as imagining. And here, that I may begin to show what 
 error is, I would have you note that acts of imagination, in 
 themselves considered, contain no error; that is, that the mind 
 does not err from the mere fact that it imagines, but only in so 
 far as it is considered as lacking the idea, which excludes the 
 existence of the things it imagines as present. For if the mind, 
 when imagining things non-existent as present, knew that these 
 things did not really exist, surely it would ascribe this power of 
 imagination to a virtue in its nature, and not to a defect, espe- 
 cially if this faculty of imagining depended solely upon its 
 nature, that is (I, def. 7), if this mental faculty were free. 
 
 PROP. 18. // the human body has once been affected simulla-
 
 202 BARUCH DE SPINOZA 
 
 neously by two or more bodies, when the mind after that imagines 
 any one of them it will forthwith call to remembrance also the 
 others. 
 
 Proof. The cause of the mind's imagining any body is (by 
 the preceding corollary), that the human body is affected and 
 disposed by the traces of an external body in the same way as it 
 was affected when certain of its parts were impelled by that 
 external body ; but (by hypothesis] the body was then so disposed 
 that the mind imagined two bodies at the same time; it will 
 therefore now, also, imagine two at the same time; and when 
 the mind imagines either, it will forthwith recollect the other. 
 Q. E. D. 
 
 Scholium. From this we clearly comprehend what memory 
 is. It is nothing but a certain concatenation of ideas, involving 
 the nature of things outside of the human body, which arises in 
 the mind according to the order and concatenation of the modi- 
 fications of the human body. I say, in the first place, that it is a 
 concatenation of those ideas only that involve the nature of 
 things outside of the human body, not of the ideas that express 
 the nature of those things; for these ideas are really (16) ideas 
 of the modifications of the human body, which involve both its 
 nature and that of external bodies. I say, in the second place, 
 that this concatenation follows the order and concatenation of 
 the modifications of the human body, to distinguish it from the 
 concatenation of ideas which follows the order of the under- 
 standing, whereby the mind perceives things through their first 
 causes, and which is the same in all men. From this, further- 
 more, we clearly understand why the mind from the thought of 
 one thing immediately passes to the thought of another which 
 bears no resemblance to the former. For example, from the 
 thought of the word pomum (apple) a Roman passes straight- 
 way to the thought of the fruit, which bears no resemblance to 
 that articulate sound, and has nothing in common with it, 
 except that the body of the same man has often been affected 
 by these two; that is, the man has of ten heard the word pomum 
 while he saw this fruit. Thus each one passes from one thought 
 to another, according as custom has ordered the images of
 
 THE ETHICS 203 
 
 things in his body. A soldier, for instance, who sees in the sand 
 the tracks of a horse, passes at once from the thought of the 
 horse to the thought of its rider, and from that to the thought 
 of war, etc. ; while a rustic passes from the thought of a horse 
 to the thought of a plow, a field, etc. Thus each one, according 
 as he has been accustomed to join and connect the images 
 of things in this or that way, passes from a given thought to 
 this thought or to that. 
 
 PROP. 19. The human mind does not come to a knowledge of the 
 human body itself, or know that it exists, except through the ideas of 
 the modifications by which the body is affected. 
 
 Proof. The human mind is the idea or knowledge of the 
 human body (13), which (9) is in God, in so far as he is consid- 
 ered as affected by the idea of another individual thing. Or 
 rather, since (postulate 4) the human body needs many bodies, 
 by which it is continually born anew, as it were; and since the 
 order and connection of ideas is (7) the same as the order and 
 connection of causes; this idea is in God, in so far as he is con- 
 sidered as affected by the ideas of many individual things. 
 Therefore God has an idea of the human body, or knows the 
 human body, in so far as he is affected by many other ideas ; and 
 not in so far as he constitutes the nature of the human mind; 
 that is (n, cor.), the human mind does not know the human 
 body. But the ideas of the modifications of the body are in 
 God, in so far as he constitutes the nature of the human mind; 
 that is, the human mind perceives these same modifications 
 (12), and consequently (16) perceives the human body itself, 
 and that (17) as really existing. Therefore, only in so far does 
 the human mind perceive the human body. Q. E. D. 
 
 PROP. 20. There is in God also an idea or knowledge of the 
 human mind, which follows in God in the same way, and is referred 
 to God in the same way, as the idea or knowledge of the human body. 
 
 Proof. Thought is an attribute of God (i); therefore (3) 
 there must necessarily be in God an idea of it and of all its modi- 
 fications, and consequently (i i) of the human mind also. In the 
 second place, it does not follow that this idea or knowledge of 
 the mind is in God in so far as he is infinite, but in so far as he is
 
 204 BARUCH DE SPINOZA 
 
 affected by another idea of an individual thing (9). But the 
 order and connection of ideas is the same as the order and con- 
 nection of causes (7). Therefore this idea or knowledge of the 
 mind follows in God, and is referred to God, in the same way as 
 the idea or knowledge of the body. Q. E. D. 
 
 PROP. 21. This idea of the mind is united to the mind in the 
 same way as the mind itself is united to the body. 
 
 Proof. We have proved that the mind is united to the body, 
 from the fact that the body is the object of the mind (12 and 13) ; 
 hence, for the same reason, the idea of the mind must be united 
 with its object, that is, with the mind itself, in the same way as 
 the mind is united with the body. Q. E. D. 
 
 Scholium. This proposition is much more clearly compre- 
 hended from what was said in the scholium to prop. 7 of this 
 Part. I there showed that the idea of the body and the body, 
 that is (13), the mind and the body, are one and the same indi- 
 vidual, conceived now under the attribute of thought, now 
 under that of extension. Hence the idea of the mind and the 
 mind itself are one and the same thing, conceived under one and 
 the same attribute, namely, that of thought. The idea of the 
 mind, I say, and the mind itself follow in God, by the same 
 necessity, from the same power of thinking. For, in truth, the 
 idea of the mind that is, the idea of an idea is nothing else 
 than the essence of an idea, in so far as this is considered as a 
 mode of thinking, and without relation to its object. For when 
 any one knows a thing, from that very fact he knows that he 
 knows it, and at the same time knows that he knows that he 
 knows it, and so to infinity. But of this more hereafter. 
 
 PROP. 22. The human mind perceives, not merely the modifica- 
 tions of the body, but also the ideas of these modifications. 
 
 Proof. The ideas of the ideas of modifications follow in 
 God in the same way, and are referred to God in the same way, 
 as the ideas of the modifications. This is proved as is prop. 20. 
 But the ideas of the modifications of the body are in the human 
 mind (12), that is (n, cor.), they are in God, in so far as he con- 
 stitutes the essence of the human mind. Hence, the ideas of 
 these ideas are in God, in so far as he has a knowledge, or idea,
 
 THE ETHICS 205 
 
 of the human mind; that is (21), they are in the human mind 
 itself, which, consequently, perceives not merely the modifi- 
 cations of the body, but also the ideas of these. Q. E. D. 
 
 PROP. 23. The mind only knows itself in so far as it perceives 
 the ideas of the modifications of the body. 
 
 Proof. The idea or knowledge of the mind (20) follows in 
 God in the same way, and is referred to God in the same way, 
 as the idea or knowledge of the body. But since (19) the human 
 mind does not know the body itself; that is (n, cor.}, since the 
 knowledge of the human body is not referred to God, in so far 
 as he constitutes the nature of the human mind; neither is the 
 knowledge of the mind referred to God, in so far as he consti- 
 tutes the essence of the human mind; and hence (n, cor.), in so 
 far the human mind does not know itself. In the second place, 
 the ideas of the modifications which the human body receives 
 involve the nature of the human body itself (16), that is (13), 
 they agree with the nature of the mind; hence the knowledge of 
 these ideas necessarily involves the knowledge of the mind. 
 But (by the preceding proposition) the knowledge of these ideas 
 is in the human mind itself. Therefore only in so far does the 
 human mind know itself. Q. E. D. 
 
 PROP. 48. There is in the mind no absolute or free will; but the 
 mind is determined to this or that volition by a cause, which has 
 itself been determined by another cause, this again by another, and 
 so to infinity. 
 
 Proof. The mind is a definite and determinate mode of 
 thinking (n), therefore (I, 17, cor. 2) it cannot be a free cause 
 of its own actions, that is, it cannot have an absolute power to 
 will or not to will. It must be determined to this or that volition 
 (I, 28) by a cause, which has itself been determined by another 
 cause, this again by another, etc. Q. E. D. 
 
 Scholium. In the same way it is proved that there is in 
 the mind no absolute power of knowing, desiring, loving, etc. 
 Whence it follows, these and similar faculties are either abso- 
 lutely fictitious, or only metaphysical entities universals 
 that we are accustomed to form from individuals. Thus, under- 
 standing and will are related to this or that idea and to this or
 
 206 BARUCH DE SPINOZA 
 
 that volition, as lapidity is related to this or that stone, or man 
 to Peter or Paul. Why men think themselves free I have ex- 
 plained in the Appendix to Part I. Before I go further, it should 
 be noted that I mean by will, not desire, but the faculty of 
 affirming and denying; I mean, I say, the faculty by which the 
 mind affirms or denies what is true or false, and not the desire 
 through which the mind seeks or avoids things. But having 
 proved these faculties to be universal notions, which are not 
 distinguished from the individuals of which we form them, it 
 remains to inquire whether the volitions themselves are any- 
 thing but just the ideas of things. It remains, I say, to inquire 
 whether there is in the mind any other affrmation or negation 
 than that involved in an idea, in that it is an idea. On this point 
 see the following proposition, and, to avoid confounding ideas 
 with pictures, see, also, def . 3 of this Part. For by ideas I do not 
 mean such images as are formed at the back of the eye, or, if you 
 please, in the middle of the brain, but the conceptions of 
 thought. 
 
 PROP. 49. There is in the mind no volition, that is, no affirma- 
 tion or negation, except that involved in an idea in that it is an idea. 
 
 Proof. There is in the mind (by the preceding proposition) 
 no absolute power to will or not to will, but only particular voli- 
 tions, namely, this or that affirmation, and this or that negation. 
 Let us conceive, therefore, some particular volition for in- 
 stance, the mode of thinking by which the mind affirms the 
 three angles of a triangle to be equal to two right angles. This 
 affirmation involves the conception or idea of a triangle, that is, 
 it cannot be conceived without the idea of a triangle; for it is 
 the same thing whether I say, A must involve the conception B, 
 or A cannot be conceived without B. In the second place, this 
 affirmation (axiom 3), without the idea of a triangle, cannot be. 
 Therefore this affirmation cannot, without the idea of a trian- 
 gle, either be or be conceived. Moreover, this idea of a triangle 
 must involve this same affirmation of the equality of its three 
 angles to two right angles. Therefore, conversely, this idea of a 
 triangle can neither be nor be conceived without this affirma- 
 tion. Hence (dcf. 2) this affirmation belongs to the essence of
 
 THE ETHICS 207 
 
 the idea of a triangle, and is nothing but that idea. What I have 
 said of this volition is (since I took it at random) to be said also 
 of every volition, namely, that it is nothing else than an idea. 
 Q. E. D. 
 
 Corollary. Will and understanding are one and the same 
 thing. 
 
 Proof. Will and understanding are nothing but particular 
 volitions and ideas (48 and schol.). But a particular volition 
 and a particular idea are (by the preceding proposition) one and 
 the same thing. Therefore will and understanding are one and 
 the same thing. Q. E. D.
 
 GOTTFRIED WILHELM VON LEIBNITZ 
 
 (1646-1716) 
 
 PHILOSOPHICAL WORKS 
 
 Translated from the French * by 
 GEORGE MARTIN DUNCAN 
 
 XI. A NEW SYSTEM OF NATURE, AND OF THE INTERACTION 
 OF SUBSTANCES, AS WELL AS OF THE UNION WHICH EX- 
 ISTS BETWEEN THE SOUL AND THE BODY. 1695 
 
 i . I CONCEIVED this system many years ago and communi- 
 cated it to some learned men, and in particular to one of the 
 greatest theologians and philosophers of our time, who, having 
 been informed of some of my opinions by a very distinguished 
 person, had found them highly paradoxical. When, however, 
 he had received my explanations, he withdrew his condemna- 
 tion in the most generous and edifying manner; and, having 
 approved a part of my propositions, he ceased censuring the 
 others with which he was not yet in accord. Since that time I 
 have continued .my meditations as far as opportunity has per- 
 mitted, in order to give to the public only thoroughly examined 
 views, and I have also tried to answer the objections made 
 against my essays in dynamics, which are related to the 
 former. Finally, as a number of persons have desired to see my 
 opinions more clearly explained, I have ventured to publish 
 these meditations although they are not at all popular nor fit to 
 be enjoyed by every sort of mind. I have been led to do this 
 principally in "order that I might profit by the judgments of 
 those who are learned in these matters, inasmuch as it would be 
 too inconvenient to seek and challenge separately those who 
 
 * From The Philosophical Works of Leibnitz, translated by G. M. Duncan, 
 New Haven, 1890.
 
 PHILOSOPHICAL WORKS 209 
 
 would be disposed to give the instructions which I shall always 
 be glad to receive, provided the love of truth appears in them 
 rather than passion for opinions already held. 
 
 2. Although I am one of those who have worked very hard at 
 mathematics I have not since my youth ceased to meditate on 
 philosophy, for it always seemed to me that there was a way to 
 establish in it, by clear demonstrations, something stable. I had 
 penetrated well into the territory of the scholastics when math- 
 ematics and modern authors induced me while yet young to 
 withdraw from it. Their fine ways of explaining nature mechan- 
 ically charmed me; and, with reason, I scorned the method of 
 those who employ only forms or faculties, by which nothing is 
 learned. But afterwards, when I tried to search into the prin- 
 ciples of mechanics to find proof of the laws of nature which 
 experience made known, I perceived that the mere considera- 
 tion of an extended mass did not suffice and that it was neces- 
 sary to employ in addition the notion of force, which is very 
 easily understood although it belongs to the province of meta- 
 physics. It seemed to me also that the opinion of those who 
 transform or degrade animals into simple machines, not with- 
 standing its seeming possibility, is contrary to appearances and 
 even opposed to the order of things. 
 
 3. In the beginning, when I had freed myself from the yoke 
 of Aristotle, I occupied myself with the consideration of the 
 void and atoms, for this is what best fills the imagination; but 
 after many meditations I perceived that it is impossible to find 
 the principles of true unity in mere matter, or in that which is 
 only passive, because there everything is but a collection or 
 mass of parts ad infinitum. Now, multiplicity cannot have its 
 reality except from real unities, which originate otherwise and 
 are entirely cjifferent things from the points of which it is cer- 
 tain the continuum could not be composed. Therefore, in order 
 to find these real unities I was compelled to resort to a formal 
 atom, since a material being could not be at the same time ma- 
 terial and perfectly indivisible, or in other words, endowed with 
 true unity. It became necessary, therefore, to recall and, as it 
 were, reinstate the substantial forms, so descried now-a-days,
 
 210 GOTTFRIED WILHELM VON LEIBNITZ 
 
 but in a way to render them intelligible, and distinguish the use 
 which ought to be made of them from the abuse which had 
 befallen them. I found then that their nature is force and that 
 from this something analogous to sensation and desire results, 
 and that therefore it was necessary to conceive them similarly 
 to the idea which we have of souls. But as the soul ought not to 
 be employed to explain the details of the economy of the animal 
 body, likewise I judged that it was not necessary to employ 
 these forms to explain particular problems in nature although 
 they are necessary in order to establish true general principles. 
 Aristotle calls them the first entelechies. I call them, perhaps 
 more intelligibly, primitive forces which contain in themselves 
 not only the act or complement of possibility, but also an 
 original activity. 
 
 4. I saw that these forms and these souls ought to be indivisi- 
 ble, just as much as our mind, .as in truth I remembered was the 
 opinion of St. Thomas in regard to the souls of brutes. But this 
 innovation renewed the great difficulties in respect to the origin 
 and duration of souls and of forms. For every simple substance 
 which has true unity cannot begin or end except by miracle; it 
 follows, therefore, that it cannot begin except by creation, nor 
 end except by annihilation. Therefore, with the exception of 
 the souls which God might still be pleased to create expressly, 
 I was obliged to recognize that the constitutive forms of sub- 
 stances must have been created with the world, and that they 
 must exist always. Certain scholastics, like Albertus Magnus 
 and John Bacon, had also foreseen a part of the truth as to their 
 origin. And the matter ought not to appear at all extraordinary 
 for only the same duration which the Gassendists accord their 
 atoms is given to these forms. 
 
 5. I was of the opinion, nevertheless, that neither spirits nor 
 the rational soul, which belong to a superior order and have 
 incomparably more perfection than these forms implanted in 
 matter which in my opinion are found everywhere being in 
 comparison with them, like little gods made in the image of God 
 and having within them some rays of the light of divinity, ought 
 to be mixed up indifferently or confounded with other forms or
 
 PHILOSOPHICAL WORKS 211 
 
 souls. This is why God governs spirits as a prince governs his 
 subjects, and even as a father cares for his children; while he 
 disposes of the other substances as an engineer manipulates his 
 machines. Thus spirits have peculiar laws which place them 
 above the changes which matter undergoes, and indeed it may 
 be said that all other things are made only for them, the changes 
 even being adapted to the felicity of the good and the punish- 
 ment of the bad. 
 
 6. However, to return to ordinary forms or to material souls 
 [dmes brutes], the duration which must be attributed to them in 
 place of that which has been attributed to atoms, might raise 
 the question as to whether they pass from body to body, which 
 would be metempsychosis very like the belief of certain phi- 
 losophers in the transmission of motion and of the species. But 
 this fancy is very far removed from the nature of things. There 
 is no such passage; and here it is that the transformations of 
 Swammerdam, Malpighi and Leewenhoeck, who are the best 
 observers of our time, have come to my aid and have made me 
 admit more easily that the animal and every other organized 
 substance does not at all begin when we think it does, and that 
 its apparent generation is only a development and a sort of 
 augmentation. Also I have noticed that the author of the 
 Search after Truth [i.e., Malebranche], Rigis, Hartsoeker and 
 other able men, have not been far removed from this opinion. 
 
 7. But the most important question of all still remained: 
 What do these souls or these forms become after the death of 
 the animal or after the destruction of the individual of the or- 
 ganized substance? It is this question which is most embarrass- 
 ing, all the more so as it seems unreasonable that souls should 
 remain uselessly in a chaos of confused matter. This obliged 
 me finally to believe that there was only one reasonable opinion 
 to hold, namely, that not only the soul but also the animal itself 
 and its organic machine were preserved, although the destruc- 
 tion of its gross parts had rendered it so small as to escape our 
 senses now just as much as it did before it was born . Also there is 
 no person who can accurately note the true time of death, which 
 can be considered for a long time solely as a suspension of vis-
 
 212 GOTTFRIED WILHELM VON LEIBNITZ 
 
 ible actions, and indeed is never anything else in mere animals; 
 witness the resuscitation of drowned flies after being buried 
 under pulverized chalk, and other similar examples, which 
 make it sufficiently clear that there would be many more resus- 
 citations and of far more intricacy if men were in condition to 
 set the machine going again. And apparently it was of some- 
 thing of this sort that the great Democritus, atomist as he was, 
 spoke, although Pliny makes sport of the idea. It is then na- 
 tural that the animal having, as people of great penetration 
 begin to recognize, been always living and organized, should so 
 remain always. And since, therefore, there is no first birth nor 
 entirely new generation of the animal, it follows that there will 
 be no final extinction nor complete death taken in its metaphy- 
 sical rigor, and that in consequence instead of the transmigra- 
 tion of souls there is only a transformation of one and the same 
 animal, according as its organs are folded differently and more 
 or less developed. 
 
 8. Nevertheless, rational souls follow very much higher laws 
 and are exempt from all that could make them lose the quality 
 of being citizens in the society of spirits, God having planned 
 for them so well, that all the changes in matter cannot make 
 them lose the moral qualities of their personality. And it can be 
 said that everything tends to the perfection not only of the uni- 
 verse in general but also of those creatures in particular who 
 are destined to such a measure of happiness that the universe 
 finds itself interested therein, by virtue of the divine goodness 
 which communicates itself to each one, according as sovereign 
 wisdom permits. 
 
 9. As regards the ordinary body of animals and of other cor- 
 poreal substances, the complete extinction of which has up to 
 this time been believed in, and the changes of which depend 
 rather upon mechanical rules than upon moral laws, I remarked 
 with pleasure that the author of the book On Diet, which is at- 
 tributed to Hippocrates, had foreseen something of the truth 
 when he said in express terms that animals are not born and do 
 not die, and that the things which are supposed to begin and to 
 perish only appear and disappear. This was also the opinion of
 
 PHILOSOPHICAL WORKS 213 
 
 Parmenides and of Melissus, according to Aristotle, for these 
 ancients were more profound than is thought. 
 
 10. I am the best disposed in the world to do justice to the 
 moderns; nevertheless I think they have carried reform too far, 
 for instance, in confounding natural things with artificial, for 
 the reason that they have not had sufficiently high ideas of the 
 majesty of nature. They conceive that the difference between 
 its machines and ours is only that of large to small. This caused 
 a very able man, author of Conversations on the Plurality of 
 Worlds', to say recently that in regarding nature close at hand 
 it is found less admirable than had been believed, being only 
 like the workshop of an artisan. I believe that this does not 
 give a worthy idea of it and that only our system can finally 
 make men realize the true and immense distance which there is 
 between the most trifling productions and mechanisms of the 
 divine wisdom and the greatest masterpieces of the art of a 
 finite mind, this difference consisting not merely in degree but 
 also in kind. It must then be known that the machines of na- 
 ture have a truly infinite number of organs and that they are so 
 well protected and so proof against all accidents that it is not 
 possible to destroy them. A natural machine remains a ma- 
 chine even to its least parts and, what is more, it remains 
 always the same machine it has been, being only transformed 
 by the different folds it receives, and sometimes expanded, 
 sometimes compressed and, as it were, concentrated when be- 
 lieved to be lost. 
 
 11. Farther, by means of the soul or of form there arises a 
 true unity which answers to what we call the I in us, that which 
 could take place neither in the machines of art nor in the simple 
 mass of matter however well organized it might be, which can 
 only be considered as an army, or as a herd of cattle, or as a 
 pond full of fish, or as a watch composed of springs and wheels. 
 Nevertheless, if there were not real substantial unities there 
 would be nothing substantial or real in the mass. It was this 
 which forced Cordemoi to abandon Descartes, and to embrace 
 Democritus' doctrine of the Atoms, in order to find a true 
 unity. But atoms of matter are contrary to reason, leaving out
 
 214 GOTTFRIED WILHELM VON LEIBNITZ 
 
 of account the proof that they are made up of parts, for the in- 
 vincible attachment of one part to another (if such a thing could 
 be conceived or with reason supposed) would not at all destroy 
 their diversity. Only atoms of substance, i.e., unities which are 
 real and absolutely destitute of parts, are sources of actions and 
 the absolute first principles of the composition of things, and, 
 as it were, the last elements of the analysis of substances. They 
 might be called metaphysical points; they possess a certain 
 vitality and a kind of perception, and mathematical points are 
 their points of view to express the universe. But when corporeal 
 substances are compressed all their organs together form only 
 physical point to our sight. Thus physical points are only indi- 
 visible in appearance; mathematical points are so in reality but 
 they are merely modalities; only metaphysical points or those 
 of substance (constituted by forms or souls) are exact and real, 
 and without them there would be nothing real, for without true 
 unities there could not be multiplicity. 
 
 12. After having established these proportions I thought 
 myself entering into port, but when I came to meditate on the 
 union of the soul with the body I was as if cast back into the 
 open sea. For I found no way of explaining how the body can 
 cause anything to pass into the soul, or vice versa; nor how one 
 substance can communicate with another created substance. 
 Descartes gave up the attempt on that point, as far as can be 
 learned from his writings, but his disciples seeing that the com- 
 mon view was inconceivable, were of the opinion that we per- 
 ceive the qualities of bodies because God causes thoughts to 
 arise in the soul on the occasion of movements of matter; and 
 when the soul wished to move the body in its turn they judged 
 that it was God who moved it for the soul. And as the com- 
 munication of motions again seemed to them inconceivable, 
 they believed that God gave motion to a body on the occasion 
 of the motion of another body. This is what they call the sys- 
 tem of Occasional Causes which has been much in vogue on 
 account of the beautiful remarks of the author of the Search 
 after Truth. 
 
 13. It must be confessed that the difficulty has been well
 
 PHILOSOPHICAL WORKS 215 
 
 penetrated when the not-possible is stated, but it does not ap- 
 pear that it is done away with by explaining what actually 
 takes place. It is indeed true that there is no real influence of 
 one created substance upon another, speaking in metaphysical 
 strictness, and that all things with all their realities are continu- 
 ally produced by the power of God ; but in resolving problems 
 it is not enough to employ a general cause and to call in what is 
 called the Deus ex Machina. For when this is done and there 
 is no other explanation which can be drawn from secondary 
 causes, it is, properly, having recourse to miracle. In philoso- 
 phy it is necessary to try to give reasons by making known in 
 what way things are done by divine wisdom, in conformity to 
 the idea of the subject concerned. 
 
 14. Being then obliged to admit that it is not possible for the 
 soul or any true substance to receive any influence from with- 
 out, if it be not by the divine omnipotence I was led insensibly 
 to an opinion which surprised me but which appears inevitable 
 and which has in truth great advantages and many beauties. It 
 is this: it must then be said that God created the soul, or every 
 other real unity, in the first place in such a way that everything 
 with it comes into existence from its own substance through 
 perfect spontaneity as regards itself and in perfect harmony with 
 objects outside itself. And that thus our internal feelings (i.e., 
 those within the soul itself and not in the brain or finer parts of 
 the body), being only phenomena consequent upon external 
 objects or true appearances, and like well-ordered dreams, it is 
 necessary that these internal perceptions within the soul itself 
 come to it by its own proper original constitution, i.e., by the 
 representative nature (capable of expressing beings outside 
 itself by relation to its organs), which has been given it at its 
 creation and which constitutes its individual character. This 
 brings it about that each of these substances in its own way and 
 according to a certain point of view, represents exactly the 
 entire universe, and perceptions or impressions of external 
 things reach the soul at the proper point in virtue of its own 
 laws, as if it were in a world apart, and as if there existed no- 
 thing but God and itself (to make use of the manner of speaking
 
 216 GOTTFRIED WILHELM VON LEIBNITZ 
 
 of a certain person of great elevation of mind, whose piety is 
 well known) ; there is also perfect harmony among all these sub- 
 stances, producing the same effects as if they communicated 
 with each other by a transmission of kinds or of qualities, as 
 philosophers generally suppose. 
 
 Farther, the organized mass, within which is the point of 
 view of the soul, being expressed more nearly by it, finds itself 
 reciprocally ready to act of itself, following the laws of cor- 
 poreal machines, at the moment when the soul wills it, without 
 either one troubling the laws of the other, the nerves and the 
 blood having just at that time received the impulse which is 
 necessary in order to make them respond to the passions and 
 perceptions of the soul; it is this mutual relationship, regulated 
 beforehand in every substance of the universe, which produces 
 what we call their inter-communication and alone constitutes the 
 union between the soul and body. And we may understand from 
 this how the soul has its seat in the body by an immediate pre- 
 sence which could not be greater, for it is there as the unit is in 
 the complex of units, which is the multitude. 
 
 15. This hypothesis is very possible. For why could not God 
 give to a substance in the beginning a nature or internal force 
 which could produce in it to order (as in a spiritual or formal 
 automaton, but free here since it has reason to its share) , all that 
 which should happen to it; that is to say all the appearances or 
 expressions it should have, and that without the aid of any 
 creature? All the more as the nature of the substance neces- 
 sarily demands and essentially includes a progress or change, 
 without which it would not have power to act. And this nature 
 of the soul, being representative, in a very exact (although 
 more or less distinct) manner, of the universe, the series of re- 
 presentations which the soul will produce for itself will naturally 
 correspond to the series of changes in the universe itself; as, in 
 turn, the body has also been accommodated to the soul, for the 
 encounters where it is conceived as acting from without. This is 
 the more reasonable as bodies are only made for those spirits 
 which are capable of entering into communion with God and of 
 celebrating His glory. Thus from the moment the possibility of
 
 PHILOSOPHICAL WORKS 217 
 
 this hypothesis of harmonies is perceived, we perceive also that it 
 is the most reasonable and that it gives a marvellous idea of the 
 harmony of the universe and of the perfection of the works of 
 God. 
 
 16. This great advantage is also found in it, that instead of 
 saying that we are FREE only in appearance and in a way prac- 
 tically sufficient, as many persons of ability have believed, it 
 must rather be said that we are only enchained in appearance, 
 and that according to the strictness of metaphysical expressions 
 we are in a state of perfect independence as respects the influ- 
 ence of all other creatures. This again places in a marvellous 
 light the immortality of the soul and the always uniform pre- 
 servation of our individuality, regulated perfectly by its own 
 nature beyond the risk of all accidents from without, whatever 
 appearance there may be to the contrary. Never has a system 
 so clearly proved our high standing. Every spirit, being like a 
 separate world sufficient to itself, independent of every other 
 creature, enclosing the infinite, expressing the universe, is as 
 durable, as stable and as absolute as the universe of creatures 
 itself. Therefore we ought always to appear in it in the way 
 best fitted to contribute to the perfection of the society of all 
 spirits, which makes their moral union in the city of God. 
 Here is found also a new proof of the existence of God, which is 
 one of surprising clearness. For this perfect harmony of so 
 many substances which have no communication with each 
 other, can only come from a common cause. 
 
 17. Besides all these advantages which render this system 
 commendable, it can also be said that this is more than an 
 hypothesis, since it hardly seems possible to explain the facts in 
 any other intelligible manner, and since several great difficulties 
 which have exercised the mind up to this time, seem to disap- 
 pear of themselves as soon as this system is well understood. 
 The customary ways of speaking can still be retained. For we 
 can say that the substance, the disposition of which explains 
 the changes in others in an intelligible manner (in this respect, 
 that it may be supposed that the others have been in this point 
 adapted to it since the beginning, according to the order of the
 
 218 GOTTFRIED WILHELM VON LEIBNITZ 
 
 decrees of God), is the one which must be conceived of as acting 
 upon the others. Also the action of one substance upon another 
 is not the emission or transfer of an entity as is commonly be- 
 lieved, and cannot be understood reasonably except in the way 
 which I have just mentioned. It is true that we can easily con- 
 ceive in matter both emissions and receptions of parts, by 
 means of which we are right in explaining mechanically all the 
 phenomena of physics; but as the material mass is not a sub- 
 stance it is apparent that action as regards substance itself can 
 only be what I have just said. 
 
 1 8. These considerations, however metaphysical they may 
 appear, have yet a marvellous use in physics in establishing the 
 laws of motion, as our Dynamics can make clear. For it can be 
 said that in the collision of bodies, each one suffers only by rea- 
 son of its own elasticity, because of the motion which is already 
 in it. And as to absolute motion, it can in no way be deter- 
 mined mathematically, since everything terminates in rela- 
 tions; therefore there is always a perfect equality of hypotheses, 
 as in astronomy, so that whatever number of bodies may be 
 taken it is arbitrary to assign repose or a certain degree of veloc- 
 ity to any one that may be chosen, without being refuted by the 
 phenomena of straight, circular and composite motion. Never- 
 theless it is reasonable to attribute to bodies real movements, 
 according to the supposition which explains phenomena in the 
 most intelligible manner, since this description is in conformity 
 to the idea of action which I have just established. 
 
 XIV. SECOND EXPLANATION OF THE SYSTEM OF THE COM- 
 MUNICATION BETWEEN SUBSTANCES. 1696 
 
 BY your [S. Foucher] reflections, sir, I see clearly that the 
 thought which one of my friends has published in the Journal 
 de Paris has need of explanation. 
 
 You do not understand, you say, how I could prove that 
 which I advanced concerning the communication or harmony 
 of two substances so different as the soul and the body. It is 
 true that I believe that I have found the means of doing so, and
 
 PHILOSOPHICAL WORKS 219 
 
 this is how I propose to satisfy you. Imagine two clocks or 
 watches which agree perfectly. Now, this may take place in 
 three ways. The first consists in a mutual influence; the second 
 is to have a skillful workman attached to them who regulates 
 them and keeps them always in accord ; the third is to construct 
 these two clocks with so much art and accuracy as to assure their 
 future harmony. Put now the soul and the body in place of 
 these two clocks; their accordance may be brought about by 
 one of these three ways. The way of influence is that of common 
 philosophy, but as we cannot conceive of material particles 
 which may pass from one of these substances into the other, 
 this view must be abandoned. The way of the continual assist- 
 ance of the creator is that of the system of occasional causes; 
 but I hold that this is to make a Deus ex Machina intervene in a 
 natural and ordinary matter, in which, according to reason, he 
 ought not to cooperate except in the way in which he does in all 
 other natural things. Thus there remains only my hypothesis; 
 that is, the way of harmony. From the beginning God has 
 made each of these two substances of such a nature that 
 merely by following its own peculiar laws, received with its 
 being, it nevertheless accords with the other, just as if there 
 were a mutual influence or as if God always put his hand thereto 
 in addition to his general cooperation. After this I have no 
 need of proving anything, unless you wish to require me to 
 prove that God is sufficiently skillful to make use of this pre- 
 venient contrivance, examples of which we see even among 
 men. Now, taking for granted that he can do it, you easily see 
 that this is the way most beautiful and most worthy of him. 
 You suspected that my explanation would be opposed to the 
 very different idea which we have of the mind and of the body; 
 but you will presently clearly see that no one has better estab- 
 lished their independence. For while it has been necessary to 
 explain their communication by a kind of miracle, occasion has 
 always been given to many people to fear that the distinction 
 between the body and the soul was not as real as was believed, 
 since in order to maintain it it was necessary to go so far. I shall 
 not be at all sorry to sound enlightened persons concerning the 
 thoughts which I have just explained to you.
 
 220 GOTTFRIED WILHELM VON LEIBNITZ 
 
 XXXII. THE PRINCIPLES OF NATURE AND OF GRACE. 1714 
 
 1. Substance is being, capable of action. It is simple or com- 
 pound. Simple substance is that which has no parts. Compound 
 substance is a collection of simple substances or monads. Monas 
 is a Greek word which signifies unity, or that which is one. 
 
 Compounds, or bodies, are multitudes; and simple sub- 
 stances, lives, souls, spirits are unities. And there must be 
 simple substances everywhere, because without simple sub- 
 stances there would be no compounds; and consequently all 
 nature is full of life. 
 
 2. Monads, having no parts, cannot be formed or decom- 
 posed. They cannot begin or end naturally; and consequently 
 last as long as the universe, which will indeed be changed but 
 will not be destroyed. They cannot have shapes; otherwise 
 they would have parts. And consequently a monad, in itself and 
 at a given moment, could not be distinguished from another ex- 
 cept by its internal qualities and actions, which can be nothing 
 else than its perceptions (that is, representations of the com- 
 pound, or of what is external, in the simple), and its appelitions 
 (that is, its tendencies from one perception to another), which 
 are the principles of change. For the simplicity of substance 
 does not prevent multiplicity of modifications, which must be 
 found together in this same simple substance, and must consist 
 in the variety of relations to things which are external. Just 
 as in a centre or point, altogether simple as it is, there is found 
 an infinity of angles formed by lines which there meet. 
 
 3. Everything in nature is full. There are everywhere simple 
 substances, separated in reality from each other by activities of 
 their own which continually change their relations; and each 
 simple substance, or monad, which forms the centre of a com- 
 pound substance (as, for example, of an animal) and the prin- 
 ciple of its unity, is surrounded by a mass composed of an in- 
 finity of other monads, which constitute the body proper of 
 this central monad; and in accordance with the affections of 
 this it represents, as a centre, the things which are outside of 
 itself. And this body is organic, when it forms a sort of automa- 

 
 PHILOSOPHICAL WORKS 221 
 
 ton or natural machine; which is a machine not only in its 
 entirety, but also in its smallest perceptible parts. And as, be- 
 cause of the plenitude of the world, everything is connected and 
 each body acts upon every other body, more or less according 
 to the distance, and by reaction is itself affected thereby; it fol- 
 lows that each monad is a mirror, living or endowed with in- 
 ternal activity, representative according to its point of view of 
 the universe, and as regulated as the universe itself. And per- 
 ceptions in the monad spring one from the other, by the law of 
 appetites or by the final causes of good and evil, which consist in 
 visible, regulated or unregulated perceptions; just as the 
 changes of bodies and external phenomena spring one from 
 another, by the laws of efficient causes, that is, of movements. 
 Thus there is perfect harmony between the perceptions of the 
 monad and the movements of bodies, established at the begin- 
 ning between the system of efficient causes and that of final 
 causes. And in this consists the accord and physical union 
 of the soul and body, although neither one can change the 
 laws of the other. 
 
 4. Each monad, with a particular body, makes a living sub- 
 stance. Thus there is not only life everywhere, provided with 
 members or organs, but also there is an infinity of degrees in 
 monads, some dominating more or less over the others. But 
 when the monad has organs so adjusted that by means of them 
 there is clearness and distinctness in the impressions which it 
 receives and consequently in the perceptions which represent 
 them (as, for example, when by means of the shape of the 
 humors of the eyes, the rays of light are concentrated and act 
 with more force); this can extend even to feeling [sentiment], 
 that is, even to a perception accompanied by memory, that is, 
 one a certain echo of which remains a long time to make itself 
 heard upon occasion; and such a living being is called an ani- 
 mal, as its monad is called a soul. And when this soul is ele- 
 vated to reason it is something more sublime and is reckoned 
 among spirits, as will soon be explained. 
 
 It is true that animals are sometimes in the condition of 
 simple living beings, and their souls in the condition of simple
 
 222 GOTTFRIED WILHELM VON LEIBNITZ 
 
 monads, namely, when their perceptions are not sufficiently 
 distinct to be remembered, as happens in a profound, dreamless 
 sleep, or in a swoon. But perceptions which have become en- 
 tirely confused must be re-developed in animals, for reasons 
 which I shall shortly (12) enumerate. Therefore it is well to 
 make a distinction between the perception, which is the internal 
 condition of the monad representing external things, and apper- 
 ception, which is consciousness or the reflective knowledge of this 
 internal state; the latter not being given to all souls, nor at all 
 times to the same soul. And it is for want of this distinction 
 that the Cartesians have failed, taking no account of the per- 
 ceptions of which we are not conscious as people take no ac- 
 count of imperceptible bodies. It is this also which made the 
 same Cartesians believe that only spirits are monads, that 
 there is no soul of brutes, and still less other principles of life. 
 
 And as they shocked too much the common opinion of men 
 by refusing feeling to brutes, they have, on the other hand, ac- 
 commodated themselves too much to the prejudices of the 
 multitude, by confounding a long swoon, caused by a great con- 
 fusion of perceptions, with death strictly speaking, where all 
 perception would cease. This confirmed the ill-founded belief 
 in the destruction of some souls, and the bad opinion of some 
 so-called strong minds, who have contended against the 
 immortality of our soul. 
 
 5. There is a continuity in the perceptions of animals which 
 bears some resemblance to reason ; but it is only founded in the 
 memory of facts, and not at all in the knowledge of causes. Thus 
 a dog shuns the stick with which it has been beaten, because 
 memory represents to it the pain which the stick has caused it. 
 And men in so far as they are empirics, that is to say, in three- 
 fourths of their actions, act simply as brutes. For example, we 
 expect that there will be daylight to-morrow, because we have 
 always had the experience; only an astronomer foresees it by 
 reason, and even this prediction will finally fail when the cause 
 of day, which is not eternal, shall cease. But true reasoning de- 
 pends upon necessary or eternal truths, such as those of logic, 
 numbers, geometry, which establish an indubitable connection
 
 PHILOSOPHICAL WORKS 223 
 
 of ideas and unfailing consequences. The animals in which 
 these consequences are not noticed, are called brutes; but those 
 which know these necessary truths are properly those which 
 are called rational animals, and their souls are called spirits. 
 These souls are capable of performing acts of reflection, and of 
 considering that which is called the ego, substance, monad, soul, 
 spirit, in a word, immaterial things and truths. It is this which 
 renders us capable of the sciences and of demonstrative know- 
 ledge. 
 
 6. Modern researches have taught us, and reason approves 
 of it, that living beings whose organs are known to us, that is to 
 say, plants and animals, do not come from putrefaction or from 
 chaos, as the ancients believed, but from pre-formed seeds, and 
 consequently by the transformation of pre-existing living be- 
 ings. There are animalcules in the seeds of large animals, which 
 by means of conception assume a new dress which they make 
 their own and by means of which they can nourish themselves 
 and increase their size, in order to pass to a larger theatre and 
 to accomplish the propagation of the large animal. It is true 
 that the souls of spermatic human animals are not rational and 
 do not become so until conception determines these animals to 
 the human nature. And as generally animals are not born alto- 
 gether in conception or generation, neither do they perish alto- 
 gether in what we call death; for it is reasonable that what does 
 not begin naturally, should not end either in the order of na- 
 ture. Therefore, quitting their mask or their rags, they merely 
 return to a more subtile theatre where they can, nevertheless, 
 be just as sensitive and just as well regulated as in the larger. 
 And what we have just said of large animals, takes place also in 
 the generation and death of smaller spermatic animals, in com- 
 parison with which the former may pass for large; for every- 
 thing extends ad infinitum in nature. 
 
 Thus not only souls, but also animals, are ingenerable and 
 imperishable: they are only developed, unfolded, reclothed, 
 unclothed, transformed: souls never quit their entire body and 
 do not pass from one body into another which is entirely new to 
 them.
 
 224 GOTTFRIED WILHELM VON LEIBNITZ 
 
 There is therefore no metempsychosis, but there is metamor- 
 phosis; animals change, take and leave only parts: the same 
 thing which happens little by little and by small invisible par- 
 ticles but continually in nutrition, and suddenly, visibly but 
 rarely in conception or death, which cause a gain or loss of 
 everything at one time. 
 
 7. Up to this time we have spoken as simple physicists: now 
 we must advance to metaphysics by making use of the great prin- 
 ciple, little employed in general, which teaches that nothing 
 happens without a sufficient reason; that is to say, that nothing 
 happens without its being possible for him who should suffi- 
 ciently understand things, to give a reason sufficient to deter- 
 mine why it is so and not otherwise. This principle laid down, 
 the first question which should rightly be asked, would-be Why 
 is there something rather than nothing? For nothing is simpler 
 and easier than something. Further, suppose that things must 
 exist, we must be able to give a reason why they must exist so 
 and not otherwise. 
 
 8. Now this sufficient reason for the existence of the universe 
 could not be found in the series of contingent things, that is, of 
 bodies and of their representations in souls; for matter being 
 indifferent in itself to motion and to rest and to this or another 
 motion, we could not find the reason of motion in it, and still 
 less of a certain motion. And although the present motion 
 which is in matter, comes from the preceding motion, and that 
 from still another preceding, yet in this way we should never 
 make any progress, go as far as we might; for the same question 
 would always remain. 
 
 Therefore it must be that the sufficient reason which has no 
 need of another reason, be outside this series of contingent 
 things and be found in a substance which is its cause, or which 
 is a necessary being, carrying the reason of its existence within 
 itself; otherwise we should still not have a sufficient reason in 
 which we could rest. And this final reason of things is called 
 God. 
 
 9. This simple primitive substance must contain in itself 
 eminently the perfections contained in the derivative sub-
 
 PHILOSOPHICAL WORKS 225 
 
 stances which are its effects; thus it will have perfect power, 
 knowledge and will : that is, it will have omnipotence and sover- 
 eign goodness. And as justice, taken generally, is only goodness 
 conformed to wisdom, there must too be sovereign justice in 
 God. The reason which has caused things to exist by him, 
 makes them still dependent upon him in existing and in work- 
 ing: and they are continually receiving from him that which 
 gives them some perfection; but the imperfection which re- 
 mains in them, comes from the essential and original limitation 
 of the creature. 
 
 10. It follows from the supreme perfection of God, that in 
 creating the universe he has chosen the best possible plan, in 
 which there is the greatest variety together with the greatest 
 order; the best arranged ground, place, time; the most results 
 produced in the most simple ways ; the most of power, know- 
 ledge, happiness and goodness in the creatures that the uni- 
 verse could permit. For since all the possibles in the under- 
 standing of God laid claim to existence in proportion to their 
 perfections, the actual world, as the resultant of all these 
 claims, must be the most perfect possible. And without this it 
 would not be possible to give a reason why things have turned 
 out so rather than otherwise. 
 
 11. The supreme wisdom of God compelled him to choose the 
 laws of movement best adjusted and most suited to abstract or 
 metaphysical reasons. He preserves there the same quantity of 
 total and absolute force, or of actions; the same quantity of 
 respective force or of reaction ; lastly the same quantity of di- 
 rective force. Farther, action is always equal to reaction, and 
 the whole effect is always equivalent to the full cause. And it is 
 not surprising that we could not by the mere consideration of 
 the efficient causes or of matter, account for those laws of move- 
 ment which have been discovered in our time, and a part of 
 which have been discovered by myself. For I have found that 
 it was necessary to have recourse to final causes, and that these 
 laws do not depend upon the principle of necessity, like logical, 
 arithmetical and geometrical truths, but upon the principle of 
 fitness, that is, upon the choice of wisdom. And this is one of the
 
 226 GOTTFRIED WILHELM VON LEIBNITZ 
 
 most efficacious and evident proofs of the existence of God, to 
 those who can examine these matters thoroughly. 
 
 12. It follows, farther, from the perfection of the supreme 
 author, that not only is the order of the entire universe the 
 most perfect possible, but also that each living mirror repre- 
 senting the universe in accordance with its point of view, that 
 is to say, that each monad, each substantial centre, must have 
 its perceptions and its desires as well regulated as is compatible 
 with all the rest. Whence it follows, still farther, that souls, 
 that is, the most dominating monads, or rather, animals, can- 
 not fail to awaken from the state of stupor in which death or 
 some other accident may put them. 
 
 13. For everything in things is regulated once for all with as 
 much order and harmony as is possible, supreme wisdom and 
 goodness not being able to act except with perfect harmony. 
 The present is big with the future, the future could be read in 
 the past, the distant is expressed in the near. One could be- 
 come acquainted with the beauty of the universe in each soul, 
 if one could unfold all its folds, which only develop visibly in 
 time. But as each distinct perception of the soul includes in- 
 numerable confused perceptions which comprise the whole uni- 
 verse, the soul itself knows the things of which it has percep- 
 tion only so far as it has distinct and clear perceptions of them. 
 
 Each soul knows the infinite, knows all, but confusedly. As 
 in walking on the sea-shore and hearing the great noise which 
 it makes, I hear the individual sounds of each wave, of which 
 the total sound is composed, but without distinguishing them ; 
 so our confused perceptions are the result of the impressions 
 which the whole universe makes upon us. It is the same with 
 each monad. God alone has a distinct consciousness of every- 
 thing, for he is the source of all. It has been well said that he is 
 as centre everywhere, but that his circumference is nowhere, 
 since without any withdrawal from this centre, everything is 
 immediately present to him. 
 
 14. As regards the rational soul, or spirit, there is something 
 in it more than in the monads, or even in simple souls. It is not 
 only a mirror of the universe of creatures, but also an image of
 
 PHILOSOPHICAL WORKS 227 
 
 the Divinity. The spirit has not only a perception of the works 
 of God, but it is even capable of producing something which 
 resembles them, although in miniature. For, to say nothing of 
 the marvels of dreams where we invent without trouble, and 
 even involuntarily, things which when awake we should have 
 to think a long time in order to hit upon, our soul is architec- 
 tonic in its voluntary actions also, and, discovering the sciences 
 according to which God has regulated things (pondere, mensura, 
 numero, etc.), it imitates, in its department and in the little 
 world where it is permitted to exercise itself, what God does in 
 the large world. 
 
 15. This is why all spirits, whether of men or of genii, enter- 
 ing by virtue of reason and of the eternal truths into a sort of 
 society with God, are members of the City of God, that is to 
 say, of the most perfect state, formed and governed by the 
 greatest and best of monarchs ; where there is no crime without 
 punishment, no good actions without proportionate recom- 
 pense; and finally as much virtue and happiness as is possible; 
 and this is not by a derangement of nature, as if what God pre- 
 pares for souls disturbed the laws of bodies, but by the very 
 order of natural things, in virtue of the harmony pre-estab- 
 lished for all time between the realms of nature and of grace, 
 between God as Architect and God as Monarch ; so that nature 
 leads to grace and grace, while making use.of nature, perfects it. 
 
 16. Thus although reason cannot teach us the details, re- 
 served to Revelation, of the great future, we can be assured by 
 this same reason that things are made in a manner surpassing 
 our desires. God also being the most perfect and most happy, 
 and consequently, the most lovable of substances, and truly 
 pure love consisting in the state which finds pleasure in the per- 
 fections and happiness of the loved object, this love ought to 
 give us the greatest pleasure of which we are capable, when 
 God is its object. 
 
 17. And it is easy to love him as we ought, if we know him as 
 I have just described. For although God is not visible to our 
 external senses, he does not cease to be very lovable and to give 
 very great pleasure. We see how much pleasure honors give
 
 228 GOTTFRIED WILHELM VON LEIBNITZ 
 
 men, although they do not at all consist in the qualities of the 
 external senses. 
 
 Martyrs and fanatics (although the affection of the latter is 
 ill-regulated), show what pleasure of the spirit can accomplish; 
 and what is more, even sensuous pleasures are reduced to con- 
 fusedly known intellectual pleasures. 
 
 Music charms us, although its beauty only consists in the 
 harmony of numbers and in the reckoning of the beats or vibra- 
 tions of sounding bodies, which meet at certain intervals, of 
 which we are not conscious and which the soul does not cease 
 to make. The pleasures which sight finds in proportions are of 
 the same nature; and those caused by the other senses amount 
 to almost the same thing, although we cannot explain it so 
 clearly. 
 
 18. It may be said that even from the present time on, the 
 love of God makes us enjoy a foretaste of future felicity. And 
 although it is disinterested, it itself constitutes our greatest 
 good and interest even if we should not seek it therein and 
 should consider only the pleasure which it gives, without re- 
 gard to the utility it produces; for it gives us perfect confidence 
 in the goodness of our author and master, producing a true 
 tranquillity of mind; not like the Stoics who force themselves 
 to patience, but by a present content which assures us of future 
 happiness. And besides the present pleasure, nothing can be 
 more useful for the future; for the love of God fulfills our hopes, 
 too, and leads us in the road of supreme happiness, because by 
 virtue of the perfect order established in the universe, every- 
 thing is done in the best possible way, as much for the general 
 good as for the greatest individual good of those who are con- 
 vinced of this and are content with the divine government; 
 this conviction cannot be wanting to those who know how to 
 love the source of all good. It is true that supreme felicity, by 
 whatever beatific vision or knowledge of God it be accompanied, 
 can never be full; because, since God is infinite, he cannot be 
 wholly known. Therefore our happiness will never, and ought 
 not to, consist in full joy, where there would be nothing farther 
 to desire, rendering our mind stupid; but in a perpetual pro- 
 gress to new pleasures and to new perfections.
 
 CHRISTIAN VON WOLFF 
 
 (1679-1754) 
 
 RATIONAL PSYCHOLOGY 
 
 Translated from the Latin * by 
 EDWARD KENNARD RAND 
 
 THE ESSENCE AND NATURE OF THE SOUL 
 
 48. The soul is a simple substance. For the soul is not body 
 (47) nor an attribute communicated to the body (46), and 
 further, neither is it a composite entity nor does it inhere in a 
 composite entity ( 119, Cosmol. 1 ). Wherefore since every entity 
 is either composite or simple ( 532, 673, Ontol. 2 ) the soul must 
 be a simple entity. 
 
 , Now since acts of thought continually change and succeed 
 one another in turn, they are to be classed with modes ( 151, 
 Ontol.) The soul, therefore, to which these modes apply, is sub- 
 ject to modification ( 764, Ontol.}, and since it is obvious that 
 the soul lasts for some time in conjunction with the body (for 
 whether it can exist apart from the body or not need not be 
 established here) it is per durable ( 766, OntoL). Certainly a 
 per durable and modifiable object is a substance. Therefore 
 the soul is a substance. 
 
 But the soul is a simple entity by the foregoing proof. There- 
 fore it is a simple substance. 
 
 53. The soul is endowed with a certain power. The soul is 
 a substance ( 48), and since perceptions succeed one another in 
 the same, and desires spring from perceptions, and perceptions 
 
 * From Christian von Wolff's Psychologia rationalis. Francof. et Lips. 1734. 
 
 1 Wolff's Cosmologia generalis. Francof. et Lips. 1731. 
 
 1 Wolff's Philosophia prima sive Ontologia. Francof. et Lips. 1730.
 
 230 CHRISTIAN VON WOLFF 
 
 again from desires, as is generally admitted in Empiric Psy- 
 chology, its condition changes ( 709, Ontol). It therefore is 
 endowed with a certain power. ( 776, Ontol.). 
 
 54. A power and a faculty of the soul are different from one 
 another. For power consists in the continual endeavor to act 
 ( 724, Ontol.}. Faculties are merely potencies of action on the 
 part of the soul ( 29, Psych. Empir. 1 ), and thus have possibili- 
 tiesof action ( 716, Ontol.). Therefore a power of the soul and 
 a faculty differ from one another ( 183, Ontol.). 
 
 56. The soul continually tends to change its conditions. For it 
 is endowed with a certain power. Wherefore, since a power 
 continually tends to change the condition of the subject in 
 which it is ( 725, Ontol.), the soul, too, through the mediation 
 of its own power, is bound to tend continually to change its 
 condition. 
 
 57. The power of the soul is absolutely simple. For the soul 
 is simple and thus lacks parts ( 673, Ontol.). Let us now sup- 
 pose that the soul has more than one power distinct from one 
 another; since each one of them consists in the continued 
 endeavor to act ( 724, Ontol.), each one requires a particular 
 subject in which it is.* And so we must conceive of several 
 actual entities distinct from one another ( 142, 183, Ontol.), 
 which when taken together with the soul will be the parts of the 
 same ( 341, Ontol). But this is altogether absurd by the proof 
 above given. 
 
 62. The soul re-presents to itself this universe in accordance 
 with the location of its organic body in the universe, conformably 
 to the mutations which a/ect the organs of sensation. For this 
 law of sensations is constant and inviolable : if a certain muta- 
 tion is produced in some organ of sensation by some sensible 
 object there coexists in the soul a sensation which may be ex- 
 plained to it in an intelligible way, or which recognises in it a 
 sufficient reason why it should be, and why it should be such as 
 it is. ( 85, Psychol. Empir.) Now sensations are perceptions 
 of external objects, which produce a change in the organs of sen- 
 sation ( 67, Psychol. Empir), and hence while the soul feels, it 
 1 Wolff's Psychologia Empirica. Francof. et Lips. 1732.
 
 RATIONAL PSYCHOLOGY 231 
 
 re-presents those objects to itself ( 24, Psychol. Empir.}. And 
 since our body is constantly in this visible world, bodies also 
 which compose the same ( 119, Cosmol.) act constantly upon 
 our body in accordance with its location in the world, or the 
 universe. It is clear, therefore, that the soul re-presents to 
 itself this universe, or this visible world, in accordance with the 
 location of our organic body in the universe, and conformably 
 to the mutations which the bodies of which it is composed 
 produce in the same. When we sleep we perceive nothing 
 clearly and distinctly ( 15). However since the soul is still in a 
 condition of preception, although all its conceptions are con- 
 fused or obscure, there is nothing to prevent it from still per- 
 ceiving obscurely its own body, and the things that impress it, 
 and hence from continuing this re-presentation of the world, so 
 that therefore it may be said without reservation that it 
 re-presents to itself this universe. 
 
 66. The essence of the soul consists in its power of re-presenting 
 (vis reprasentiva) the universe, which power is materially limited 
 by its location in an organic body in the universe, and formally 
 limited by the constitution of the sensory organs. For this power 
 is the first principle which is conceived with regard to the soul, 
 and on which depend the other attributes which are inherent in 
 it ( 65). Therefore the essence of the soul consists in the same 
 ( 168, Ontol.). 
 
 67. The nature of the soul consists in the same re-presenting 
 power (vis reprtzsentiva) . For by this power of the soul every- 
 thing is activated that is possible through the faculties of the 
 soul. Wherefore since we understand by the nature of the soul 
 that principle of mutations in the soul which is intrinsic in the 
 same, just as by the nature of the universe we understand that 
 principle of mutations in the world which is intrinsic in the 
 same ( 503, Cosmol.) ; and since this principle of mutations is 
 power ( 8o7,Ow/0/.), and since the power with which the soul 
 is endowed ( 53) is only the power of re-presenting (vis 
 reprasentiva) the universe (62), that power of re-presenting 
 (vis reprasentiva) the universe is likewise the nature of the 
 soul.
 
 JOHN LOCKE 
 
 (1632-1704) 
 
 AN ESSAY CONCERNING HUMAN UNDER- 
 STANDING* 
 
 BOOK I 
 CHAPTER I. INTRODUCTION 
 
 1. An inquiry into the understanding, pleasant and useful. 
 Since it is the understanding that sets man above the rest of sens- 
 ible beings, and gives him all the advantage and dominion 
 which he has over them, it is certainly a subject, even for its 
 nobleness, worth our labour to inquire into. The understand- 
 ing, like the eye, whilst it makes us see and perceive all other 
 things, takes no notice of itself; and it requires art and pains to 
 set it at a distance, and make it its own object. But whatever be 
 the difficulties that lie in the way of this inquiry, whatever it be 
 that keeps us so much in the dark to ourselves, sure I am that 
 all the light we can let in upon our own minds, all the acquaint- 
 ance we can make with our own understandings, will not only 
 be very pleasant, but bring us great advantage in directing 
 our thoughts in the search of other things. 
 
 2. Design. This therefore being my purpose, to inquire 
 into the original, certainty, and extent of human knowledge, 
 together with the grounds and degrees of belief, opinion, and 
 assent, I shall not at present meddle with the physical con- 
 sideration of the mind, or trouble myself to examine wherein its 
 essence consists or by what motions of our spirits, or alterations 
 of our bodies, we come to have any sensation by our organs, or 
 any ideas in our understandings; and whether those ideas do, in 
 their formation, any or all of them, depend on matter or not: 
 
 * London, 1690 ; ad col. ed. 1694 ; 3d ed. 1697 ; 4th col. ed. 1700 ; ed. A. C. 
 Eraser, 2 vols. Oxford, 1894.
 
 CONCERNING HUMAN UNDERSTANDING 233 
 
 these are speculations which, however curious and entertaining, 
 I shall decline, as lying out of my way in the design I am now 
 upon. It shall suffice to my present purpose, to consider the dis- 
 cerning faculties of a man, as they are employed about the 
 objects which they have to do with; and I shall imagine I. have 
 not wholly misemployed myself in the thoughts I shall have on 
 this occasion, if, in this historical, plain method, I can give any 
 account of the ways whereby our understandings come to 
 attain those notions of things we have, and can set down any 
 measures of the certainty of our knowledge, or the grounds of 
 those persuasions which are to be found amongst men, so vari- 
 ous, different, and wholly contradictory; and yet asserted 
 somewhere or other with such assurance and confidence, that he 
 that shall take a view of the opinions of mankind, observe their 
 opposition, and at the same time consider the fondness and 
 devotion wherewith they are embraced, the resolution and 
 eagerness wherewith they are maintained, may perhaps have 
 reason to suspect that either there is no such thing as truth at 
 all, or that mankind hath no sufficient means to attain a certain 
 knowledge of it. 
 
 3. Method. It is therefore worth while to search out the 
 bounds between opinion and knowledge, and examine by what 
 measures, in things whereof we have no certain knowledge, we 
 ought to regulate our assent, and moderate our persuasions. In 
 order whereunto, I shall pursue this following method: 
 
 First. I shall inquire into the original of those ideas, notions, 
 or whatever else you please to call them, which a man observes, 
 and is conscious to himself he has in his mind; and the ways 
 whereby the understanding comes to be furnished with them. 
 
 Secondly. I shall endeavour to show what knowledge the 
 understanding hath by those ideas, and the certainty, evidence, 
 and extent of it. 
 
 Thirdly. I shall make some inquiry into the nature and 
 grounds of faith or opinion; whereby I mean, that assent which 
 we give to any proposition as true, of whose truth yet we have 
 no certain knowledge: and here we shall have occasion to 
 examine the reasons and degrees of assent.
 
 234 JOHN LOCKE 
 
 BOOK II 
 
 CHAPTER I. OF IDEAS IN GENERAL, AND THEIR 
 
 ORIGINAL 
 
 1. Idea is the object of thinking. Every man being con- 
 scious of himself, that he thinks, and that which his mind is 
 applied about, whilst thinking, being the ideas that are there, it 
 is past doubt that men have in their mind several ideas, such as 
 are those expressed by the words, whiteness, hardness, sweet- 
 ness, thinking, motion, man, elephant, army, drunkenness, and 
 others: it is in the first place then to be inquired, How he comes 
 by them? I know it is a received doctrine, that men have native 
 ideas and original characters stamped upon their minds in their 
 very first being. This opinion I have at large examined already; 
 and, I suppose, what I have said in the foregoing book will be 
 much more easily admitted, when I have shown whence the 
 understanding may get all the ideas it has, and by what ways 
 and degrees they may come into the mind; for which I shall 
 appeal to every one's own observation and experience. 
 
 2. All ideas come from sensation or reflection. Let us then 
 suppose the mind to be, as we say, white paper, void of all char- 
 acters, without any ideas: How comes it to be furnished? 
 Whence comes it by that vast store, which the busy and bound- 
 less fancy of man has painted on it with an almost endless 
 variety? Whence has it all the materials of reason and know- 
 ledge? To this I answer, in one word, From experience. In that 
 all our knowledge is founded, and from that it ultimately 
 derives itself. Our observation, employed either about external 
 sensible objects, or about the internal operations of our mind, 
 perceived and reflected on by ourselves, is that which supplies 
 our understandings with all the materials of thinking. These 
 two are the fountains of knowledge, from whence all the ideas 
 we have, or can naturally have, do spring. 
 
 3. The object of sensation one source of ideas. First. Our 
 senses, conversant about particular sensible objects, do convey 
 into the mind several distinct perceptions of things, according
 
 CONCERNING HUMAN UNDERSTANDING 235 
 
 to those various ways wherein those objects do affect them ; and 
 thus we come by those ideas we have of yellow, white, heat, 
 cold, soft, hard, bitter, sweet, and all those which we call sens- 
 ible qualities; which when I say the senses convey into the 
 mind, I mean, they from external objects convey into the mind 
 what produces there those perceptions. This great source 
 of most of the ideas we have, depending wholly upon our 
 senses, and derived by them to the understanding, I call, 
 SENSATION. 
 
 4. The operations of our minds the other source of them. 
 Secondly. The other fountain, from which experience furnish- 
 eth the understanding with ideas, is the perception of the opera- 
 tions of our own minds within us, as it is employed about the 
 ideas it has got; which operations when the soul comes to reflect 
 on and consider, do furnish the understanding with another set 
 of ideas which could not be had from things without; and such 
 are perception, thinking, doubting, believing, reasoning, know- 
 ing, willing, and all the different actings of our own minds; 
 which we, being conscious of, and observing in ourselves, do 
 from these receive into our understandings as distinct ideas, as 
 we do from bodies affecting our senses. This source of ideas 
 every man has wholly in himself; and though it be not sense as 
 having nothing to do with external objects, yet it is very like it, 
 and might properly enough be called internal sense. But as I 
 call the other sensation, so I call this REFLECTION, the ideas it 
 affords being such only as the mind gets by reflecting on its 
 own operations within itself. By reflection, then, in the follow- 
 ing part of this discourse, I would be understood to mean that 
 notice which the mind takes of its own operations, and the 
 manner of them, by reason whereof there come to be ideas of 
 these operations in the understanding. These two, I say, viz., 
 external material things as the objects of sensation, and the 
 operations of our own minds within as the objects of reflection, 
 are, to me, the only originals from whence all our ideas take 
 their beginnings. The term operations here, I use in a large 
 sense, as comprehending not barely the actions of the mind 
 about its ideas, but some sort of passions arising sometimes
 
 236 JOHN LOCKE 
 
 from them, such as is the .satisfaction or uneasiness arising 
 from any thought. 
 
 5. All our ideas are of the one or the other of these. The 
 understanding seems to me not to have the least glimmering of 
 any ideas which it doth not receive from one of these two. Ex- 
 ternal objects furnish the mind with the ideas of sensible quali- 
 ties, which are all those different perceptions they produce in 
 us; and the mind furnishes the understanding with ideas of its 
 own operations. 
 
 These, when we have taken a full survey of them, and their 
 several modes [combinations, and relations], we shall find to 
 contain all our whole stock of ideas; and that we have nothing 
 in our minds which did not come in one of these two ways. Let 
 any one examine his own thoughts, and thoroughly search into 
 his understanding, and then let him tell me, whether all the 
 original ideas he has there, are any other than of the objects of 
 his senses, or of the operations of his mind considered as objects 
 of his reflection ; and how great a mass of knowledge soever he 
 imagines to be lodged there, he will, upon taking a strict view, 
 see that he has not any idea in his mind but what one of these 
 two have imprinted, though perhaps with infinite variety com- 
 pounded and enlarged by the understanding, as we shall see 
 hereafter. 
 
 CHAPTER II. OF SIMPLE IDEAS 
 
 i. Uncompounded appearances. The better to understand 
 the nature, manner, and extent of our knowledge, one thing 
 is carefully to be observed concerning the ideas we have; and 
 that is, that some of them are simple, and some complex. 
 
 Though the qualities that affect our senses are, in the things 
 themselves, so united and blended that there is no separation, 
 no distance between them; yet it is plain the ideas they produce 
 in the mind enter by the senses simple and unmixed. For 
 though the sight and touch often take in from the same object, 
 at the same time, different ideas as a man sees at once
 
 CONCERNING HUMAN UNDERSTANDING 237 
 
 motion and colour, the hand feels softness and warmth in the 
 same piece of wax yet the simple ideas thus united in the 
 same subject are as perfectly distinct as those that come in by 
 different senses; the coldness and hardness which a man feels in 
 a piece of ice being as distinct ideas in the mind as the smell and 
 whiteness of a lily, or as the taste of sugar and smell of a rose : 
 and there is nothing can be plainer to a man than the clear and 
 distinct perception he has of those simple ideas; which, being 
 each in itself uncompounded, contains in it nothing but one 
 uniform appearance or conception in the mind, and is not dis- 
 tinguishable into different ideas. 
 
 2. The mind can neither make nor destroy them. These 
 simple ideas, the materials of all our knowledge, are suggested 
 and furnished to the mind only by those two ways above men- 
 tioned, viz., sensation and reflection. When the understanding 
 is once stored with these simple ideas, it has the power to 
 repeat, compare, and unite them, even to an almost infinite 
 variety, and so can make at pleasure new complex ideas. But 
 it is not in the power of the most exalted wit or enlarged under- 
 standing, by any quickness or variety of thought, to invent or 
 frame one new simple idea in the mind, not taken in by the 
 ways before mentioned; nor can any force of the understand- 
 ing destroy those that are there: the dominion of man in this 
 little world of his own understanding, being much-what the 
 same as it is in the great world of visible things, wherein his 
 power, however managed by art and skill, reaches no farther 
 than to compound and divide the materials that are made to 
 his hand but can do nothing towards the making the least par- 
 ticle of new matter, or destroying one atom of what is already 
 in being. . . . 
 
 CHAPTER III. OF SIMPLE IDEAS OF SENSE 
 
 i. Division of simple ideas. The better to conceive the 
 ideas we receive from sensation, it may not be amiss for us to 
 consider them in reference to the different ways whereby they 
 make their approaches to our minds, and make themselves per- 
 ceivable by us.
 
 238 JOHN LOCKE 
 
 First, then, there are some which come into our minds by one 
 sense only. 
 
 Secondly. There are others that convey themselves into the 
 mind by more senses than one. 
 
 Thirdly. Others that are had from reflection only. 
 
 Fourthly. There are some that make themselves way, and 
 are suggested to the mind, by all the ways of sensation and 
 reflection. 
 
 We shall consider them apart under these several heads. 
 
 1 . There are some ideas which have admittance only through 
 one sense, which is peculiarly adapted to receive them. Thus 
 light and colours, as white, red, yellow, blue, with their several 
 degrees or shades and mixtures, as green, scarlet, purple, sea- 
 green, and the rest, come in only by the eyes; all kinds of 
 noises, sounds, and tones, only by the ears; the several tastes 
 and smells, by the nose and palate. And if these organs, or the 
 nerves which are the conduits to convey them from without to 
 their audience in the brain, the mind's presence-room (as I 
 may so call it), are, any of them, so disordered as not to perform 
 their functions, they have no postern to be admitted by, no 
 other way to bring themselves into view, and be received by 
 the understanding. 
 
 The most considerable of those belonging to the touch are 
 heat, and cold, and solidity; all the rest consisting almost 
 wholly in the sensible configuration, as smooth and rough ; or 
 else more or less firm adhesion of the parts, as hard and soft, 
 tough and brittle are obvious enough. 
 
 2. I think it will be needless to enumerate all the particular 
 simple ideas belonging to each sense. Nor indeed is it possible 
 if we would, there being a great many more of them belonging 
 to most of the senses than we have names for. ... I shall 
 therefore, in the account of simple ideas I am here giving, con- 
 tent myself to set down only such as are most material to our 
 present purpose, or are in themselves less apt to be taken notice 
 of, though they are very frequently the ingredients of our com- 
 plex ideas; amongst which I think I may well account "solid- 
 ity," which therefore I shall treat of in the next chapter.
 
 CONCERNING HUMAN UNDERSTANDING 239 
 
 CHAPTER IV. IDEA OF SOLIDITY 
 
 1. We receive this idea from touch. The idea of solidity we 
 receive by our touch ; and it arises from the resistance which we 
 find in body to the entrance of any other body into the place it 
 possesses, till it has left it. There is no idea which we receive 
 more constantly from sensation than solidity. Whether we 
 move or rest, in what posture soever we are, we always feel 
 something under us that supports us, and hinders our farther 
 sinking downwards; and the bodies which we daily handle make 
 us perceive that whilst they remain between them, they do, by 
 an insurmountable force, hinder the approach of the parts of our 
 hands that press them. That which thus hinders the approach 
 of two bodies, when they are moving one towards another, I 
 call solidity. I will not dispute whether this acceptation of the 
 word "solid" be nearer to its original signification than that 
 which mathematicians use it in; it suffices that, I think, the 
 common notion of "solidity," will allow, if not justify, this use 
 of it; but if any one think it better to call it impenetrability, he 
 has my consent. Only I have thought the term solidity the 
 more proper to express this idea, not only because of its vulgar 
 use in that sense, but also because it carries something more of 
 positive in it than impenetrability, which is negative, and is, 
 perhaps, more a consequence of solidity than solidity itself. 
 This, of all other, seems the idea most intimately connected 
 with and essential to body, so as nowhere else to be found or 
 imagined but only in matter; and though our senses take no 
 notice of it but in masses of matter, of a bulk sufficient to cause 
 a sensation in us; yet the mind, having once got this idea from 
 such grosser sensible bodies, traces it farther and considers it, 
 as well as figure, in the minutest particle of matter that can 
 exist, and finds it inseparably inherent in body, wherever or 
 however modified. 
 
 2. Solidity fills space. This is the idea which belongs to 
 body, whereby we conceive it to fill space. The idea of which 
 filling of space is, that where we imagine any space taken up by
 
 240 JOHN LOCKE 
 
 a solid substance, we conceive it so to possess it that it excludes 
 all other solid substances, and will for ever hinder any two 
 other bodies, that move towards one another in a straight line, 
 from coming to touch one another, unless it removes from be- 
 tween them in a line not parallel to that which they move in. 
 This idea of it, the bodies which we ordinarily handle suffi- 
 ciently furnish us with. 
 
 6. What it is. If any one asks me, What this solidity is, I 
 send him to his senses to inform him: let him put a flint or a 
 football between his hands, and then endeavour to join them, 
 and he will know. If he thinks this not a sufficient explication 
 of solidity, what it is, and wherein it consists, I promise to tell 
 him what it is, and wherein it consists, when he tells me what 
 thinking is, or wherein it consists; or explains to me what ex- 
 tension or motion is, which perhaps seems much easier. The 
 simple ideas we have are such as experience teaches them us; 
 but if, beyond that, we endeavour by words to make them 
 clearer in the mind, we shall succeed no better than if we went 
 about to clear up the darkness of a blind man's mind by talking, 
 and to discourse into him the ideas of light and colours. The 
 reason of this I shall show in another place. 
 
 CHAPTER VI. OF SIMPLE IDEAS OF REFLECTION 
 
 1. Simple ideas of reflection are the operations of the mind 
 about its other ideas. The mind, receiving the ideas men- 
 tioned in the foregoing chapters from without, when it turns its 
 view inward upon itself, and observes its own actions about 
 those ideas it has, takes from thence other ideas, which are as 
 capable to be the objects of its contemplation as any of those it 
 received from foreign things. 
 
 2. The idea of perception, and idea of willing, we have from 
 reflection. The two great and principal actions of the mind, 
 which are most frequently considered, and which are so fre- 
 quent that every one that pleases may take notice of them in 
 himself, are these two: Perception or Thinking; and Volition or 
 Willing. [The power of thinking is called the Understanding,
 
 CONCERNING HUMAN UNDERSTANDING 241 
 
 and the power of volition is called the Will; and these two powers 
 or abilities in the mind are denominated "faculties."] . 
 
 CHAPTER VII. OF SIMPLE IDEAS OF BOTH SENSA- 
 TION AND REFLECTION 
 
 1. Pleasure and pain. There be other simple ideas which 
 convey themselves into the mind by all the ways of sensation 
 and reflection; viz., pleasure or delight, and its opposite, pain or 
 uneasiness; power, existence, unity. 
 
 2. Delight or uneasiness, one or other of them, join them- 
 selves to almost all our ideas both of sensation and reflection; 
 and there is scarce any affection of our senses from without, any 
 retired thought of our mind within, which is not able to produce 
 in us pleasure or pain. By "pleasure" and "pain," I would be 
 understood to signify whatsoever delights or molests us; whether 
 it arises from the thoughts of our minds, or any thing operating 
 on our bodies. For whether we call it "satisfaction, delight, 
 pleasure, happiness," &c., on the one side; or "uneasiness, 
 trouble, pain, torment, anguish, misery," &c., on the other; 
 they are still but different degrees of the same thing, and belong 
 to the ideas of pleasure and pain, delight or uneasiness; which 
 are the names I shall most commonly use for those two sorts of 
 ideas. 
 
 6. Pleasure and pain. Though what I have here said may 
 not perhaps make the ideas of pleasure and pain clearer to us 
 than our own experience does, which is the only way that we 
 are capable of having them ; yet the consideration of the reason 
 why they are annexed to so many other ideas, serving to give us 
 due sentiments of the wisdom and goodness of the Sovereign 
 Disposer of all things, may not be unsuitable to the main end of 
 these inquiries: the knowledge and veneration of Him being the 
 chief end of all our thoughts, and the proper business of all our 
 understandings. 
 
 7. Existence and unity. Existence and unity are two other 
 ideas that are suggested to the understanding by every object 
 without, and every idea within. When ideas are in our minds,
 
 242 JOHN LOCKE 
 
 we consider them as being actually there, as well as we consider 
 things to be actually without us: which is, that they exist, or 
 have existence: and whatever we can consider as one thing, 
 whether a real being or idea, suggests to the understanding 
 the idea of unity. 
 
 8. Power. Power also is another of those simple ideas 
 which we receive from sensation and reflection. For, observing 
 in ourselves that we do and can think, and that we can at 
 pleasure move several parts of our bodies which were at rest; 
 the effects also that natural bodies are able to produce in one 
 another occurring every moment to our senses, we both these 
 ways get the idea of power. 
 
 9. Succession. Besides these there is another idea, which 
 though suggested by our senses, yet is more constantly offered 
 us by what passes in our minds; and that is the idea of succes- 
 sion. For if we look immediately into ourselves, and reflect on 
 what is observable there,, we shall find our ideas always, whilst 
 we are awake or have any thought, passing in train, one going 
 and another coming without intermission. 
 
 10. Simple ideas the materials of all our knowledge. These, 
 if they are not all, are at least (as I think) the most considerable 
 of those simple ideas which the mind has, and out of which is 
 made all its other knowledge: all of which it receives only by the 
 two forementioned ways of sensation and reflection. 
 
 CHAPTER VIII. SOME FURTHER CONSIDERA- 
 TIONS CONCERNING OUR SIMPLE 
 IDEAS OF SENSATION 
 
 7. Ideas in the mind, qualities in bodies. To discover the 
 nature of our ideas the better, and to discourse of them intel- 
 ligibly, it will be convenient to distinguish them, as they are 
 ideas or perceptions in our minds: and as they are modifica- 
 tions of matter in the bodies that cause such perceptions in us; 
 that so we may not think (as perhaps usually is done) that they 
 are exactly the images and resemblances of something inherent
 
 CONCERNING HUMAN UNDERSTANDING 243 
 
 in the subject; most of those of sensation being in the mind no 
 more the likeness of something existing without us than the 
 names that stand for them are the likeness of our ideas, which 
 yet upon hearing they are apt to excite in us. 
 
 8. Whatsoever the mind perceives in itself, or is the immedi- 
 ate object of perception, thought, or understanding, that I call 
 idea; and the power to produce any idea in our mind, I call 
 quality of the subject wherein that power is. Thus a snowball 
 having the power to produce in us the ideas of white, cold, and 
 round, the powers to produce those ideas in us as they are in the 
 snowball, I call qualities; and as they are sensations or percep- 
 tions in our understandings, I call them "ideas"; which ideas, 
 if I speak of them sometimes as in the things themselves, I 
 would be understood to mean those qualities in the objects 
 which produce them in us. 
 
 9. Primary qualities. [Qualities thus considered in bodies 
 are, First, such as are utterly inseparable from the body, in what 
 estate soever it be;] and such as, in all the alterations and 
 changes it suffers, all the force can be used upon it, it constantly 
 keeps; and such as sense constantly finds in every particle of 
 matter which has bulk enough to be perceived, and the mind 
 finds inseparable from every particle of matter, though less than 
 to make itself singly be perceived by our senses ; e.g., take a grain 
 of wheat, divide it into two parts, each part has still solidity, 
 extension, figure, and mobility; divide it again, and it retains 
 still the same qualities: and so divide it on till the parts become 
 insensible, they must retain still each of them all those quali- 
 ties. For, division (which is all that a mill or pestle or any other 
 body does upon another, in reducing it to insensible parts) can 
 never take away either solidity, extension, figure, or mobility 
 from any body, but only makes two or more distinct separate 
 masses of matter of that which was but one before; all which 
 distinct masses, reckoned as so many distinct bodies, after divi- 
 sion, make a certain number. [These I call original or primary 
 qualities of body, which I think we may observe to produce 
 simple ideas in us, viz., solidity, extension, figure, motion or 
 rest, and number.
 
 244 JOHN LOCKE 
 
 10. Secondary qualities. Secondly. Such qualities, which 
 in truth are nothing in the objects themselves, but powers to 
 produce various sensations in us by their primary qualities, i.e., 
 by the bulk, figure, texture, and motion of their insensible 
 parts, as colours, sounds, tastes, &c., these I call secondary 
 qualities. To these might be added a third sort, which are 
 allowed to be barely powers, though they are as much real qual- 
 ities in the subject as those which I, to comply with the com- 
 mon way of speaking, call qualities, but, for distinction, second- 
 ary qualities. For, the power in fire to produce a new colour or 
 consistency in wax or clay, by its primary qualities, is as 
 much a quality in fire as the power it has to produce in me a 
 new idea or sensation of warmth or burning, which I felt not 
 before, by the same primary qualities, viz., the bulk, texture, 
 and motion of its insensible parts.] 
 
 11. [How primary qualities produce their ideas. The next 
 thing to be considered is, how bodies produce ideas in us; and 
 that is manifestly by impulse, the only way which we can con- 
 ceive bodies to operate in.] 
 
 12. If, then, external objects be not united to our minds 
 when they produce ideas therein ; and yet we perceive these 
 original qualities in such of them as singly fall under our senses, 
 it is evident that some motion must be thence continued by our 
 nerves, or animal spirits, by some parts of our bodies, to the 
 brains or the seat of sensation, there to produce in our minds 
 the particular ideas we have of them. And since the extension, 
 figure, number, and motion of bodies of an observable bigness, 
 may be perceived at a distance by the sight, it is evident some 
 singly imperceptible bodies must come from them to the eyes, 
 and thereby convey to the brain some motion which produces 
 these ideas which we have of them in us. 
 
 13. How secondary. After the same manner that the ideas 
 of these original qualities are produced in us, we may conceive 
 that the ideas of secondary qualities are also produced, viz., by 
 the operation of insensible particles on our senses. For it being 
 manifest that there are bodies, and good store of bodies, each 
 whereof are so small that we cannot by any of our senses dis-
 
 CONCERNING HUMAN UNDERSTANDING 245 
 
 cover either their bulk, figure, or motion (as is evident in the 
 particles of the air and water, and other extremely smaller than 
 those, perhaps as much smaller than the particles of air or water 
 as the particles of air or water are smaller than peas or hail- 
 stones) : let us suppose at present that the different motions and 
 figures, bulk and number, of such particles, effecting the several 
 organs of our senses, produce in us those different sensations 
 which we have from the colours and smells of bodies; e.g., that 
 a violet, by the impulse of such insensible particles of matter of 
 peculiar figures and bulks, and in different degrees and modifi- 
 cations of their motions, causes the ideas of the blue colour and 
 sweet scent of that flower to be produced in our minds ; it being 
 no more impossible to conceive that God should annex such 
 ideas to such motions, with which they have no similitude, than 
 that he should annex the idea of pain to the motion of a piece of 
 steel dividing our flesh, with which the idea hath no resem- 
 blance. 
 
 14. What I have said concerning colours and smells may be 
 understood also of tastes and sounds, and other the like sens- 
 ible qualities; which, whatever reality we by mistake attribute 
 to them, are in truth nothing in the objects themselves, but 
 powers to produce various sensations in us, and depend on 
 those primary qualities, viz., bulk, figure, texture, and motion 
 of parts [as I have said]. 
 
 15. Ideas of primary qualities are resemblances; of secondary, 
 not. From whence I think it is easy to draw this observation, 
 that the ideas of primary qualities of bodies are resemblances of 
 them, and their patterns do really exist in the bodies them- 
 selves; but the ideas produced in us by these secondary qual- 
 ities have no resemblance of them at all. There is nothing like 
 our ideas existing in the bodies themselves. They are, in the 
 bodies we denominate from them, only a power to produce 
 those sensations in us; and what is sweet, blue, or warm in idea, 
 is but the certain bulk, figure, and motion of the insensible parts 
 in the bodies themselves, which we call so. 
 
 23. Three sorts of qualities in bodies. The qualities then 
 that are in bodies, rightly considered, are of three sorts:
 
 246 JOHN LOCKE 
 
 First. The bulk, figure, number, situation, and motion or 
 rest of their solid parts; those are in them, whether we perceive 
 them or not; and when they are of that size that we can dis- 
 cover them, we have by these ideas of the thing as it is in itself, 
 as is plain in artificial things. These I call primary qualities. 
 
 Secondly. The power that is in any body, by reason of its 
 insensible primary qualities, to operate after a peculiar manner 
 on any of our senses, and thereby produce in us the different 
 ideas of several colours, sounds, smells, tastes, &c. These are 
 usually called sensible qualities. 
 
 Thirdly. The power that is in any body, by reason of the 
 particular constitution of its primary qualities, to make such a 
 change in the bulk, figure, texture, and motion of another body, 
 as to make it operate on our senses differently from what it did 
 before. Thus the sun has a power to make wax white, and fire, 
 to make lead fluid. [These are usually called powers.] 
 
 The first of these, as has been said, I think may be properly 
 called real, original, or primary qualities, because they are in 
 the things themselves, whether they are perceived or no; and 
 upon their different modifications it is that the secondary qual- 
 ities depend. 
 
 The other two are only powers to act differently upon other 
 things, which powers result from the different modifications of 
 those primary qualities. 
 
 CHAPTER IX. OF PERCEPTION 
 
 i. Perception the first simple idea of reflection. Perception, 
 as it is the first faculty of the mind exercised about our ideas, 
 so it is the first and simplest idea we have from reflection, and 
 is by some called " thinking" in general. Though thinking, in 
 the propriety of the English tongue, signifies that sort of opera- 
 tion of the mind about its ideas wherein the mind is active; 
 where it, with some degree of voluntary attention, considers 
 any thing: for in bare, naked perception, the mind is, for the 
 most part, only passive, and what it perceives it cannot avoid 
 perceiving.
 
 CONCERNING HUMAN UNDERSTANDING 247 
 
 2. Is only when the mind receives the impression. What 
 perception is, every one will know better by reflecting on what 
 he does himself, when he sees, hears, feels, &c., or thinks, than 
 by any discourse of mine. Whoever reflects on what passes in 
 his own mind, cannot miss it; and if he does not reflect, all the 
 words in the world cannot make him have .any notion of it. 
 
 3. This is certain, that whatever alterations are made in the 
 body, if they reach not the mind; whatever impressions are 
 made on the outward parts, if they are not taken notice of 
 within; there is no perception. Fire may burn our bodies with 
 no other effect than it does a billet, unless the motion be con- 
 tinued to the brain, and there the sense of heat or idea of pain 
 be produced in the mind, wherein consists actual perception. 
 
 8. Ideas of sensation often changed by the judgment. We are 
 farther to consider concerning perception, that the ideas we 
 receive by sensation are often in grown people altered by the 
 judgment without our taking notice of it. When we set before 
 our eyes a round globe of any uniform colour, e.g., gold, ala- 
 baster, or jet, it is certain that the idea thereby imprinted in 
 our mind is of a flat circle variously shadowed, with several 
 degrees of light and brightness coming to our eyes. But we 
 having, by use, been accustomed to perceive what kind of ap- 
 pearance convex bodies are wont to make in us ; what altera- 
 tions are made in the reflections of light by the difference of the 
 sensible figures of bodies ; the judgment presently, by an habit- 
 ual custom, alters the appearances into their causes; so that, 
 from that which truly is variety of shadow or colour collecting 
 the figure, it makes it pass for a mark of figure, and frames to 
 itself the perception of a convex figure and an uniform colour; 
 when the idea we receive from thence is only a plane variously 
 coloured, as is evident in painting. [To which purpose I shall 
 here insert a problem of that very ingenious and studious pro- 
 moter of real knowledge, the learned and worthy Mr. Molin- 
 eaux, which he was pleased to send me in a letter some months 
 since: and it is this: " Suppose a man born blind, and now adult, 
 and taught by his touch to distinguish between a cube and a 
 sphere of the same metal, and nighly of the same bigness, so as
 
 248 JOHN LOCKE 
 
 to tell, when he felt one and the other, which is the cube, which 
 the sphere. Suppose then the cube and sphere placed on a 
 table, and the blind man to be made to see; quaere, Whether by 
 his sight, before he touched them, he could now distinguish and 
 tell which is the globe, which the cube?" To which the acute 
 and judicious proposer answers: "Not. For though he has 
 obtained the experience of how a globe, how a cube, affects his 
 touch; yet he has not yet obtained the experience, that what 
 affects his touch so or so, must affect his sight so or so ; or that a 
 protuberant angle in the cube, that pressed his hand unequally, 
 shall appear to his eye as it does in the cube." I agree with this 
 thinking gentleman whom I am proud to call my friend, in his 
 answer to this his problem; and am of opinion, that the blind 
 man, at first sight, would not be able with certainty to say 
 which was the globe, which the cube, whilst he only saw them ; 
 though he could unerringly name them by his touch, and cer- 
 tainly distinguish them by the difference of their figures felt. 
 This I have set down, and leave with my reader, as an occasion 
 for him to consider how much he may be beholden to experi- 
 ence, improvement, and acquired notions, where he thinks he 
 has not the least use of, or help from them. And the rather, 
 because this observing gentleman farther adds, that having 
 upon the occasion of my book proposed this to divers very 
 ingenious men, he hardly ever met with one that at first gave 
 the answer to it which he thinks true, till by hearing his reasons 
 they were convinced.] 
 
 9. But this is not, I think, usual in any of our ideas but those 
 received by sight; because sight, the most comprehensive of all 
 our senses, conveying to our minds the ideas of light and col- 
 ours, which are peculiar only to that sense; and also the far 
 different ideas of space, figure and motion, the several varieties 
 whereof change the appearances of its proper objects, viz., light 
 and colours; we bring ourselves by use to judge of the one by 
 the other. This, in many cases, by a settled habit in things 
 whereof we have frequent experience, is performed so constantly 
 and so quick, that we take that for the perception of our sensa- 
 tion which is an idea formed by our judgment; so that one, viz.,
 
 CONCERNING HUMAN UNDERSTANDING 249 
 
 that of sensation, serves only to excite the other, and is scarce 
 taken notice of itself; as a man who reads or hears with atten- 
 tion and understanding, takes little notice of the characters or 
 sounds, but of the ideas that are excited in him by them. 
 
 15. Perception the inlet of knowledge. Perception, then, 
 being theirs/ step and degree towards knowledge, and the inlet 
 of all the materials of it, the fewer senses any man as well as any 
 other creature hath; and the fewer and duller the impressions 
 are that are made by them ; and the duller the faculties are that 
 are employed about them, the more remote are they from 
 that knowledge which is to be found in some men. But this, 
 being in great variety of degrees (as may be perceived amongst 
 men), cannot. certainly be discovered in the several species of 
 animals, much less in their particular individuals. It suffices 
 me only to have remarked here, that perception is the first 
 operation* of all our intellectual faculties, and the inlet of all 
 knowledge into our minds. . . . 
 
 CHAPTER XII. OF COMPLEX IDEAS 
 
 i. Made by the mind out of simple ones. We have hitherto 
 considered those ideas, in the reception whereof the mind is 
 only passive, which are those simple ones received from sensa- 
 tion and reflection before mentioned, whereof the mind cannot 
 make one to itself, nor have any idea which does not wholly 
 consist ol them. [But as the mind is wholly passive in the recep- 
 tion of alt its simple ideas, so it exerts several acts of its own, 
 whereby out of its simple ideas, as the materials and founda- 
 tions of the rest, the other are framed. The acts of the mind 
 
 * The other operations of the mind discussed by Locke under simple ideas 
 are retention or memory, discerning, comparing, compounding, and abstraction. 
 He then concludes in part as follows: chap, xi, 15. These are the beginnings 
 of human knowledge. And thus I have given a short and, I think, true history 
 of the first beginnings of human knowledge, whence the mind has its first objects, 
 and by what steps it makes its progress to the laying in and storing up those 
 ideas out of which is to be framed all the knowledge it is capable of; wherein 
 I must appeal to experience and observation whether I am in the right: the best 
 way to come to truth being to examine things as really they are, and not to con- 
 clude they are as we fancy of ourselves, or have been taught by others to imagine.
 
 250 JOHN LOCKE 
 
 wherein it exerts its power over its simple ideas are chiefly these 
 three: (i) Combining several simple ideas into one compound 
 one; and thus all complex ideas are made. (2) The second is 
 bringing two ideas, whether simple or complex, together, and 
 setting them by one another, so as to take a view of them at 
 once, without uniting them into one; by which way it gets all 
 its ideas cf relations. (3) The third is separating them from all 
 other ideas that accompany them in their real existence; this 
 is called "abstraction": and thus all its general ideas are made. 
 This shows man's power and its way of operation to be much 
 the same in the material and intellectual world. For, the 
 materials in both being such as he has no power over, either to 
 make or destroy, all that man can do is either to unite them 
 together, or to set them by one another, or wholly separate 
 them. I shall here begin with the first of these in the considera- 
 tion of complex ideas, and come to the other two in their due 
 places.] * As simple ideas are observed to exist in several com- 
 binations united together, so the mind has a power to consider 
 several of them united together as one idea; and that not only 
 as they are united in external objects, but as itself has joined 
 them. Ideas thus made up of several simple ones put together I 
 call complex; such as are beauty, gratitude, a man, an army, 
 the universe; which, though complicated of various simple ideas 
 or complex ideas made up of simple ones, yet are, when the 
 mind pleases, considered each by itself as one entire thing, and 
 signified by one name. 
 
 2. Made voluntarily. In this faculty of repeating and join- 
 ing together its ideas, the mind has great power in varying and 
 multiplying the objects of its thoughts infinitely beyond what 
 sensation or reflection furnished it with; but all this still con- 
 fined to those simple ideas which it received from those two 
 sources, and which are the ultimate materials of all its composi- 
 tions. For, simple ideas are all from things themselves ; and of 
 these the mind can have no more nor other than what are sug- 
 gested to it. It can have no other ideas of sensible qualities 
 
 * Brackets indicate deviations from the first edition of the Essay found by 
 A. C. Fraser in the three other editions of Locke's lifetime.
 
 CONCERNING HUMAN UNDERSTANDING 251 
 
 than what come from without by the senses, nor any ideas of 
 other kind of operations of a thinking substance than what it 
 finds in itself: but when it has once got these simple ideas, it is 
 not confined barely to observation, and what offers itself from 
 without ; it can, by its own power, put together those ideas it has, 
 and make new complex ones which it never received so united. 
 
 3. Are either modes, substances, or relations. Complex 
 ideas, however compounded and decompounded, though their 
 number be infinite, and the variety endless wherewith they fill 
 and entertain the thoughts of men, yet I think they may be all 
 reduced under these three heads: i. Modes. 2. Substances. 
 3. Relations. 
 
 4. Modes. First. Modes I call such complex ideas which, 
 however compounded, contain not in them the supposition of 
 subsisting by themselves, but are considered as dependences on, 
 or affections of, substances; such are the ideas signified by the 
 words, "triangle, gratitude, murder," &c. And if in this I use 
 the word "mode" in somewhat a different sense from its ordin- 
 ary signification, I beg pardon; it being unavoidable in dis- 
 courses differing from the ordinary received notions, either to 
 make new words or to use old words in somewhat a new signi- 
 fication: the latter whereof, in our present case, is perhaps the 
 more tolerable of the two. 
 
 5. Simple and mixed modes. Of these modes there are two 
 sorts which deserve distinct consideration. First. There are 
 some which are only variations or different combinations of the 
 same simple idea, without the mixture of any other, as a dozen, 
 or score; which are nothing but the ideas of so many distinct 
 units added together: and these I call simple modes, as being 
 contained within the bounds of one simple idea. Secondly. 
 There are others compounded of simple ideas, of several kinds, 
 put together to make one complex one, e.g., beauty, consisting 
 of a certain composition of colour and figure, causing delight 
 in the beholder; theft, which, being the concealed change of the 
 possession of any thing, without the consent of the proprietor, 
 contains, as is visible, a combination of several ideas of several 
 kinds; and these I call mixed modes.
 
 252 JOHN LOCKE 
 
 6. Substances single or collective. Secondly. The ideas of 
 substances are such combinations of simple ideas as are taken 
 to represent distinct particular things subsisting by themselves, 
 in which the supposed or confused idea of substance, such as it 
 is, is always the first and chief. Thus, if to substance be joined 
 the simple idea of a certain dull, whitish colour, with certain 
 degrees of weight, hardness, ductility, and fusibility, we have 
 the idea of lead; and a combination of the ideas of a certain sort 
 of figure, with the powers of motion, thought, and reasoning, 
 joined to substance, make the ordinary idea of a man. Now of 
 substances also there are two sorts of ideas: one of single 
 substances, as they exist separately, as of a man or a sheep ; the 
 other of several of those put together, as an army of men or 
 flock of sheep which collective ideas of several substances 
 thus put together, are as much each of them one single idea as 
 that of a man or an unit. 
 
 7. Relation. Thirdly. The last sort of complex ideas is 
 that we call Relation, which consists in the consideration and 
 comparing one idea with another. Of these several kinds we 
 shall treat in their order. 
 
 8. The abstrusest ideas from the two sources. If we trace 
 the progress of our minds, and with attention observe how it 
 repeats, adds together, and unites its simple ideas received from 
 sensation or reflection, it will lead us farther than at first per- 
 haps we should have imagined. And I believe we shall find, if 
 we warily observe the originals of our notions, that even the 
 most abstruse ideas, how remote soever they may seem from 
 sense, or from any operation of our own minds, are yet only 
 such as the understanding frames to itself, by repeating and 
 joining together ideas that it had either from objects of sense, 
 or from its own operations about them ; so that those even large 
 and abstract ideas are derived from sensation or reflection, 
 being no other than what the mind, by the ordinary use of its 
 own faculties, employed about ideas received from objects of 
 sense, or from the operations it observes in itself about them, 
 may and does attain unto.
 
 CONCERNING HUMAN UNDERSTANDING 253 
 
 BOOK IV 
 CHAPTER I. OF KNOWLEDGE IN GENERAL 
 
 1 . Our Knowledge conversant about our Ideas. Since the 
 mind, in all its thoughts and reasonings, hath no other imme- 
 diate object but its own ideas, which it alone does or can con- 
 template, it is evident that our knowledge is only conversant 
 about them. 
 
 2. Knowledge is the Perception of the Agreement or Disagree- 
 ment of two Ideas. Knowledge, then, seems to me to be 
 nothing but the perception of the connexion and agreement, 
 or disagreement and repugnancy of any of our ideas. In this 
 alone it consists. Where this perception is, there is knowledge; 
 and where it is not, there, though we may fancy, guess, or 
 believe, yet we always come short of knowledge. For when we 
 know that white is not black, what do we else but perceive 
 that these two ideas do not agree? When we possess ourselves 
 with the utmost security of the demonstration, that the three 
 angles of a triangle are equal to two right ones, what do we 
 more but perceive, that equality to two right ones does neces- 
 sarily agree to, and is inseparable from the three angles of a 
 triangle? 
 
 3. This Agreement fourfold. But to understand a little 
 more distinctly wherein this agreement or disagreement con- 
 sists, I think we may reduce it all to these four sorts: 
 
 I. Identity, or diversity. 
 II. Relation. 
 
 III. Co-existence, or necessary connexion. 
 
 IV. Real existence. 
 
 4. First, Of Identity, or Diversity. First, As to the first 
 sort of agreement or disagreement, viz., identity or diversity. 
 It is the first act of the mind, when it has any sentiments or 
 ideas at all, to perceive its ideas; and so far as it perceives them, 
 to know each what it is, and thereby also to perceive their 
 difference, and that one is not another. This is so absolutely 
 necessary, that, without it, there could be no knowledge, no
 
 254 JOHN LOCKE 
 
 reasoning, no imagination, no distinct thoughts at all. By this 
 the mind clearly and infallibly perceives each idea to agree 
 with itself, and to be what it is; and all distinct ideas to disagree, 
 i.e., the one not to be the other; and this it does without pains, 
 labour, or deduction; but at first view, by its natural power of 
 perception and distinction. And though men of art have 
 reduced this into those general rules, "what is, is," and "it is 
 impossible for the same thing to be and not to be," for ready 
 application in all cases, wherein there may be occasion to 
 reflect it on: yet it is certain, that the first exercise of this 
 faculty is about particular ideas. A man infallibly knows, as 
 soon as ever he has them in his mind, that the ideas he calls 
 white and round are the very ideas they are, and that they are 
 not other ideas which he calls red or square. Nor can any 
 maxim or proposition in the world make him know it clearer or 
 surer than he did before, and without any such general rule. 
 This, then, is the first agreement or disagreement which the 
 mind perceives in its ideas, which it always perceives at first 
 sight: and if there ever happen any doubt about it, it will 
 always be found to be about the names, and not the ideas 
 themselves, whose identity and diversity will always be per- 
 ceived as soon and clearly as the ideas themselves are; nor can 
 it possibly be otherwise. 
 
 5. Secondly, Relative. Secondly, The next sort of agree- 
 ment or disagreement the mind perceives in any of its ideas 
 may, I think, be called relative, and is nothing but the per- 
 ception of the relation between any two ideas, of what kind 
 soever, whether substances, modes, or any other. For, since 
 all distinct ideas must eternally be known not to be the same, 
 and so be universally and constantly denied one of another, 
 there could be no room for any positive knowledge at all, if 
 we could not perceive any relation between our ideas, and 
 find out the agreement or disagreement they have one with 
 another, in several ways the mind takes of comparing them. 
 
 6. Thirdly, Of Co-existence. Thirdly, The third sort of 
 agreement or disagreement to be found in our ideas, which 
 the perception of the mind is employed about, is co-existence
 
 CONCERNING HUMAN UNDERSTANDING 255 
 
 or non-co-existence in the same subject ; and this belongs par- 
 ticularly to substances. Thus, when we pronounce concerning 
 gold, that it is fixed, our knowledge of this truth amounts to no 
 more but this, that fixedness, or a power to remain in the fire 
 unconsumed, is an idea that always accompanies and is joined 
 with that particular sort of yellowness, weight, fusibility, malle- 
 ableness, and solubility in aq. regia, which make our complex 
 idea, signified by the word gold. 
 
 7. Fourthly. Of real Existence. Fourthly, The fourth and 
 last sort is that of actual and real existence agreeing to any 
 idea. Within these four sorts of agreement or disagreement 
 is, I suppose, contained all the knowledge we have, or are 
 capable of: for all the inquiries we can make concerning any 
 of our ideas, all that we know or can affirm concerning any of 
 them is, that it is, or is not, the same with some other; that it 
 does or does not always co-exist with some other idea in the 
 same subject ; that it has this or that relation with some other 
 idea; or that it has a real existence without the mind. Thus, 
 blue is not yellow, is of identity: two triangles upon equal 
 bases between two parallels are equal, is of relation: iron is 
 susceptible of magnetical impressions, is of co-existence: God 
 is, is of real existence. Though identity and co-existence are 
 truly nothing but relations, yet they are such peculiar ways of 
 agreement or disagreement of our ideas, that they deserve well 
 to be considered as distinct heads, and not under relation in 
 general; since they are so different grounds of affirmation and 
 negation, as will easily appear to any one, who will but reflect 
 on what is said in several places of this essay. . . .
 
 GEORGE BERKELEY 
 
 (1685-1753) 
 
 AN ESSAY TOWARDS A NEW THEORY OF VISION* 
 
 1. MY design is (a) to shew the manner wherein we perceive 
 by sight the Distance, Magnitude, and Situation of objects; 
 also (b) to consider the difference there is betwixt the ideas of 
 Sight and Touch, and whether there be any idea common to 
 both senses. 
 
 2. It is, I think, agreed by all that Distance of itself, and 
 immediately, cannot be seen. For distance being a line directed 
 endwise to the eye, it projects only one point in the fund of 
 the eye which point remains invariably the same, whether 
 the distance be longer or shorter. 
 
 3. I find it also acknowledged that the estimate we make 
 of the distance of objects considerably remote is rather an act 
 of judgment grounded on experience than of sense. For ex- 
 ample, when I perceive a great number of intermediate objects, 
 such as houses, fields, rivers, and the like, which I have experi- 
 enced to take up a considerable space, I thence form a judg- 
 ment or conclusion, that the object I see beyond them is at a 
 great distance. Again, when an object appears faint and small 
 which at a near distance I have experienced to make a vigorous 
 and large appearance, I instantly conclude it to be far off. - 
 And this, it is evident, is the result of experience; without 
 which, from the faintness and littleness, I should not have 
 inferred anything concerning the distance of objects. 
 
 4. But, when an object is placed at so near a distance as 
 that the interval between the eyes bears any sensible propor- 
 tion to it, the opinion of speculative men is, that the two optic 
 
 * Dublin, 1709; Lond., 1711; ib., 1732, etc.
 
 A NEW THEORY OF VISION 257 
 
 axes (the fancy that we see only with one eye at once being 
 exploded), concurring at the object, do there make an angle, 
 by means of which, according as it is greater or lesser, the 
 object is perceived to be nearer or farther off. 
 
 5. Betwixt which and the foregoing manner of estimating 
 distance there is this remarkable difference: that, whereas 
 there was no apparent necessary connexion between small 
 distance and a large and strong appearance, or between great 
 distance and a little and faint appearance, there appears a 
 very necessary connexion between an obtuse angle and near 
 distance, and an acute angle and farther distance. It does not 
 in the least depend upon experience, but may be evidently 
 known by any one before he had experienced it, that the nearer 
 the concurrence of the optic axes the greater the angle, and the 
 remoter their concurrence is the lesser will be the angle com- 
 prehended by them. 
 
 6. There is another way, mentioned by optic writers, 
 whereby they will have us judge of those distances in respect 
 of which the breadth of the pupil hath any sensible bigness. 
 And that is the greater or lesser divergency of the rays, which, 
 issuing from the visible point, do fall on the pupil that point 
 being judged nearest which is seen by most diverging rays, 
 and that remoter which is seen by less diverging rays; and so 
 on, the apparent distance still increasing, as the divergency of 
 the rays decreases, till at length it becomes infinite when the 
 rays that fall on the pupil are to sense parallel. And after this 
 manner it is said we perceive distance when we look only with 
 one eye. 
 
 7. In this case also it is plain we are not beholden to expe- 
 rience: it being a certain, necessary truth that, the nearer the 
 direct rays falling on the eye approach to a parallelism, the 
 farther off is the point of their intersection, or the visible point 
 from whence they flow. 
 
 8. Now, though the accounts here given of perceiving near 
 distance by sight are received for true, and accordingly made 
 use of in determining the apparent places of objects, they do
 
 258 GEORGE BERKELEY 
 
 nevertheless seem to me very unsatisfactory, and that for these 
 following reasons : 
 
 9. First, It is evident that, when the mind perceives any 
 idea, not immediately and of itself, it must be by the means 
 of some other idea. Thus, for instance, the passions which 
 are in the mind of another are of themselves to me invisible. 
 I may nevertheless perceive them by sight, though not imme- 
 diately, yet by means of the colours they produce in the counte- 
 nance. We often see shame or fear in the looks of a man, by 
 perceiving the changes of his countenance to red or pale. 
 
 10. Moreover, it is evident that no idea which is not itself 
 perceived can be to me the means of perceiving any other idea. 
 If I do not perceive the redness or paleness of a man's face 
 themselves, it is impossible I should perceive by them the 
 passions which are in his mind. 
 
 11. Now, from sect, ii., it is plain that distance is in its own 
 nature imperceptible, and yet it is perceived by sight. It 
 remains, therefore, that it be brought into view by means of 
 some other idea, that is itself immediately perceived in the act 
 of vision. 
 
 12. But those lines and angles by means whereof some 
 men pretend to explain the perception of distance, are them- 
 selves not at all perceived, nor are they in truth ever thought 
 of by those unskilful in optics. I appeal to any one's expe- 
 rience, whether, upon sight of an object, he computes its dis- 
 tance by the bigness of the angle made by the meeting of the 
 two optic axes? or whether he ever thinks of the greater or 
 lesser divergency of the rays which arrive from any point to 
 his pupil? nay, whether it be not perfectly impossible for him 
 to perceive by sense the various angles wherewith the rays, 
 according to their greater or lesser divergence, do fall on the 
 eye? Every one is himself the best judge of what he perceives, 
 and what not. In vain shall any man tell me, that I perceive 
 certain lines and angles which introduce into my mind the 
 various ideas of distance, so long as I myself am conscious 
 of no such thing. 
 
 13. Since therefore those angles and lines are not themselves
 
 A NEW THEORY OF VISION 259 
 
 perceived by sight, it follows, from sect, x., that the mind does 
 not by them judge of the distance of objects. 
 
 14. Secondly, The truth of this assertion will be yet farther 
 evident to any one that considers those lines and angles have 
 no real existence in nature, being only an hypothesis framed 
 by the mathematicians, and by them introduced into optics 
 that they might treat of that science in a geometrical way. 
 
 15. The third and last reason I shall give for rejecting that 
 doctrine is, that though we should grant the real existence of 
 those optic angles, &c., and that it was possible for the mind to 
 perceive them, yet these principles would not be found suffi- 
 cient to explain the phenomena of distance, as shall be shewn 
 hereafter. 
 
 1 6. Now, it being already shewn that distance is suggested 
 to the mind, by the mediation of some other idea which is itself 
 perceived in the act of seeing, it remains that we inquire what 
 ideas or sensations there be that attend vision unto which we 
 may suppose the ideas of distance are connected, and by which 
 they are introduced into the mind. 
 
 And, first, it is certain by experience, that when we look at a 
 near object with both eyes, according as it approaches or 
 recedes from us, we alter the disposition of our eyes, by lessen- 
 ing or widening the interval between the pupils. This disposi- 
 tion or turn of the eyes is attended with a sensation, which 
 seems to me to be that which in this case brings the idea of 
 greater or lesser distance into the mind. 
 
 17. Not that there is any natural or necessary connexion 
 between the sensation we perceive by the turn of the eyes 
 and greater or lesser distance. But because the mind has, 
 by constant experience, found the different sensations corre- 
 sponding to the different dispositions of the eyes to be attended 
 each with a different degree of distance in the object there 
 has grown an habitual or customary connexion between those 
 two sorts of ideas; so that the mind no sooner perceives the 
 sensation arising from the different turn it gives the eyes, in 
 order to bring the pupils nearer or farther asunder, but it
 
 260 GEORGE BERKELEY 
 
 withal perceives the different idea of distance which was wont 
 to be connected with that sensation. Just as, upon hearing 
 a certain sound, the idea is immediately suggested to the 
 understanding which custom had united with it. 
 
 18. Nor do I see how I can easily be mistaken in this matter. 
 I know evidently that distance is not perceived of itself that, 
 by consequence, it must be perceived by means of some other 
 idea, which is immediately perceived, and varies with the dif- 
 ferent degrees of distance. I know also that the sensation 
 arising from the turn of the eyes is of itself immediately per- 
 ceived, and various degrees thereof are connected with differ- 
 ent distances, which never fail to accompany them into my 
 mind, when I view an object distinctly with both eyes whose 
 distance is so small that in respect of it the interval between 
 the eyes has any considerable magnitude. 
 
 19. I know it is a received opinion that, by altering the 
 disposition of the eyes, the mind perceives whether the angle 
 of the optic axes, or the lateral angles comprehended between 
 the interval of the eyes or the optic axes, are made greater 
 or lesser; and that, accordingly, by a kind of natural geometry, 
 it judges the point of their intersection to be nearer or farther 
 off. But that this is not true I am convinced by my own experi- 
 ence, since I am not conscious that I make any such use of the 
 perception I have by the turn of my eyes. And for me to make 
 those judgments, and draw those conclusions from it, without 
 knowing that I do so, seems altogether incomprehensible. 
 
 20. From all which it follows, that the judgment we make 
 of the distance of an object viewed with both eyes is entirely 
 the result of experience. If we had not constantly found cer- 
 tain sensations, arising from the various dispositions of the 
 eyes, attended with certain degrees of distance, we should never 
 make those sudden judgments from them concerning the dis- 
 tance of objects ; no more than we would pretend to judge of a 
 man's thoughts by his pronouncing words we had never heard 
 before. 
 
 21. Secondly, an object placed at a certain distance from the 
 eye, to which the breadth of the pupil bears a considerable
 
 A NEW THEORY OF VISION 261 
 
 proportion, being made to approach, is seen more confusedly. 
 And the nearer it is brought the more confused appearance it 
 makes. And, this being found constantly to be so, there arises 
 in the mind an habitual connexion between the several degrees 
 of confusion and distance; the greater confusion still imply- 
 ing the lesser distance, and the lesser confusion the greater 
 distance of the object. 
 
 22. This confused appearance of the object doth therefore 
 seem to be the medium whereby the mind judges of distance, 
 in those cases wherein the most approved writers of optics 
 will have it judge by the different divergency with which the 
 rays flowing from the radiating point fall on the pupil. No 
 man, I believe, will pretend to see or feel those imaginary angles 
 that the rays are supposed to form according to their various 
 inclinations on his eye. But he cannot choose seeing whether 
 the object appear more or less confused. It is therefore a 
 manifest consequence from what has been demonstrated that, 
 instead of the greater or lesser divergency of the rays, the mind 
 makes use of the greater or lesser confusedness of the appear- 
 ance, thereby to determine the apparent place of an object. 
 
 23. Nor doth it avail to say there is not any necessary con- 
 nexion between confused vision and distance great or small. 
 For I ask any man what necessary connexion he sees between 
 the redness of a blush and shame? And yet no sooner shall he 
 behold that colour to arise in the face of another but it brings 
 into his mind the idea of that passion which hath been ob- 
 served to accompany it. 
 
 24. What seems to have misled the writers of optics in this 
 matter is, that they imagine men judge of distance as they do 
 of a conclusion in mathematics; betwixt which and the pre- 
 mises it is indeed absolutely requisite there be an apparent, 
 necessary connexion. But it is far otherwise in the sudden 
 judgments men make of distance. We are not to think that 
 brutes and children, or even grown reasonable men, whenever 
 they perceive an object to approach or depart from them, do it 
 by virtue of geometry and demonstration. 
 
 25. That one idea may suggest another to the mind, it will
 
 262 GEORGE BERKELEY 
 
 suffice that they have been observed to go together, without 
 any demonstration of the necessity of their coexistence, or 
 without so much as knowing what it is that makes them so to 
 coexist. Of this there are innumerable instances, of which no 
 one can be ignorant. 
 
 26. Thus, greater confusion having been constantly attended 
 with nearer distance, no sooner is the former idea perceived but 
 it suggests the latter to our thoughts. And, if it had been the 
 ordinary course of nature that the farther off an object were 
 placed the more confused it should appear, it is certain the very 
 same perception that now makes us think an object approaches 
 would then have made us to imagine it went farther off that 
 perception, abstracting from custom and experience, being 
 equally fitted to produce the idea of great distance, or small 
 distance, or no distance at all. 
 
 27. Thirdly, an object being placed at the distance above 
 specified, and brought nearer to the eye, we may nevertheless 
 prevent, at least for some time, the appearance's growing more 
 confused, by straining the eye. In which case that sensation 
 supplies the place of confused vision, in aiding the mind to 
 judge of the distance of the object; it being esteemed so much 
 the nearer by how much the effort or straining of the eye in 
 order to distinct vision is greater. 
 
 28. I have here set down those sensations of ideas that seem 
 to be the constant and general occasions of introducing into the 
 mind the different ideas of near distance. It is true, in most 
 cases, that divers other circumstances contribute to frame our 
 idea of distance, viz. the particular number, size, kind, &c. of 
 the things seen. Concerning which, as well as all other the fore- 
 mentioned occasions which suggest distance, I shall only 
 observe, they have none of them, in their own nature, any rela- 
 tion or connexion with it: nor is it possible they should ever 
 signify the various degrees thereof, otherwise than as by expe- 
 rience they have been found to be connected with them. 
 
 41. From what has been premised, it is a manifest conse- 
 quence, that a man born blind, being made to see, would at
 
 A NEW THEORY OF VISION 263 
 
 first have no idea of Distance by sight: the sun and stars, the 
 remotest objects as well as the nearer, would all seem to be in 
 his eye, or rather in his mind. The objects intromitted by sight 
 would seem to him (as in truth they are) no other than a new 
 set of thoughts or sensations, each whereof is as near to him 
 as the perceptions of pain or pleasure, or the most inward 
 passions of his soul. For, our judging objects perceived by 
 sight to be at any distance, or without the mind, is (vid. sect. 
 28) entirely the effect of experience, which one in those cir- 
 cumstances could not yet have attained to. 
 
 42. It is indeed otherwise upon the common supposition 
 that men judge of distance by the angle of the optic axes, just 
 as one in the dark, or a blind man by the angle comprehended 
 by two sticks, one whereof he held in his hand. For, if this 
 were true, it would follow that one blind from his birth, being 
 made to see, should stand in need of no new experience, in order 
 to perceive distance by sight. But that this is false has, I think, 
 been sufficiently demonstrated. 
 
 43. And perhaps, upon a strict inquiry, we shall not find 
 that even those who from their birth have grown up in a con- 
 tinued habit of seeing are irrecoverably prejudiced on the other 
 side, to wit, in thinking what they see to be at a distance from 
 them. For, at this time it seems agreed on all hands, by those 
 who have had any thoughts of that matter, that colours, which 
 are the proper and immediate object of sight, are not without the 
 mind. But then, it will be said, by sight we have also the ideas 
 of extension, and figure, and motion; all which may well be 
 thought without and at some distance from the mind, though 
 colour should not. In answer to this, I appeal to any man's 
 experience, whether the visible extension of any object do not 
 appear as near to him as the colour of that object; nay, whether 
 they do not both seem to be in the very same place. Is not the 
 extension we see coloured, and is it possible for us, so much as 
 in thought,. to separate and abstract colour from extension? 
 Now, where the extension is, there surely is the figure, and 
 there the motion too. I speak of those which are perceived by 
 sight.
 
 264 GEORGE BERKELEY 
 
 44. But, for a fuller explication of this point, and to shew 
 that the immediate objects of sight are not so much as the 
 ideas or resemblances of things placed at a distance, it is 
 requisite that we look nearer into the matter, and carefully 
 observe what is meant in common discourse when one says, 
 that which he sees is at a distance from him. Suppose, for 
 example, that looking at the moon I should say it were fifty 
 or sixty semidiameters of the earth distant from me. Let us 
 see what moon this is spoken of. It is plain it cannot be the 
 visible moon, or anything like the visible moon, or that which 
 I see which is only a round luminous plain, of about thirty 
 visible points in diameter. For, in case I am carried from the 
 place where I stand directly towards the moon, it is manifest 
 the object varies still as I go on; and, by the time that I am 
 advanced fifty or sixty semidiameters of the earth, I shall be so 
 far from being near a small, round, luminous flat that I shall 
 perceive nothing like it this object having long since disap- 
 peared, and, if I would recover it, it must be by going back to 
 the earth from whence I set out. Again, suppose I perceive by 
 sight the faint and obscure idea of something, which I doubt 
 whether it be a man, or a tree, or a tower, but judge it to be at 
 the distance of about a mile. It is plain I cannot mean that 
 what I see is a mile off, or that it is the image or likeness of any- 
 thing which is a mile off; since that every step I take towards 
 it the appearance alters, and from being obscure, small, and 
 faint, grows clear, large, and vigorous. And when I come to 
 the mile's end, that which I saw first is quite lost, neither do I 
 find anything in the likeness of it. 
 
 45. In these and the like instances, the truth of the matter, 
 I find, stands thus: Having of a long time experienced cer- 
 tain ideas perceivable by touch as distance, tangible figure, 
 and solidity to have been connected with certain ideas of 
 sight, I do, upon perceiving these ideas of sight, forthwith con- 
 clude what tangible ideas are, by the wonted ordinary course 
 of nature, like to follow. Looking at an object, I perceive a 
 certain visible figure and colour, with some degree of faintness 
 and other circumstances, which, from what I have formerly
 
 A NEW THEORY OF VISION 265 
 
 observed, determine me to think that if I advance forward so 
 many paces, miles, &c., I shall be affected with such and such 
 ideas of touch. So that, in truth and strictness of speech, I 
 neither see distance itself, nor anything that I take to be at a 
 distance. I say, neither distance nor things placed at a distance 
 are themselves, or their ideas, truly perceived by sight. This 
 I am persuaded of, as to what concerns myself. And I believe 
 whoever will look narrowly into his own thoughts, and examine 
 what he means by saying he sees this or that thing at a dis- 
 tance, will agree with me, that what he sees only suggests to his 
 understanding that, after having passed a certain distance, to 
 be measured by the motion of his body, which is perceivable by 
 touch, he shall come to perceive such and such tangible ideas, 
 which have been usually connected with such and such visible 
 ideas. But, that one might be deceived by these suggestions 
 of sense, and that there is no necessary connexion between 
 visible and tangible ideas suggested by them, we need go no 
 farther than the next looking-glass or picture to be convinced. 
 Note that, when I speak of tangible ideas, I take the word 
 idea for any immediate object of sense or understanding in 
 which large signification it is commonly used by the moderns. 
 
 46. From what we have shewn, it is a manifest consequence 
 that the ideas of Space, Outness, and things placed at a dis- 
 tance are not, strictly speaking, the object of sight; they are 
 not otherwise perceived by the eye than by the ear. Sitting 
 in my study I hear a coach drive along the street; I look 
 through the casement and see it; I walk out and enter into it. 
 Thus, common speech would incline one to think I heard, saw, 
 and touched the same thing, to wit, the coach. It is neverthe- 
 less certain the ideas intromitted by each sense are widely 
 different, and distinct from each other; but, having been ob- 
 served constantly to go together, they are spoken of as one and 
 the same thing. By the variation of the noise, I perceive the 
 different distances of the coach, and know that it approaches 
 before I look out. Thus, by the ear I perceive distance just 
 after the same manner as I do by the eye. 
 
 47. I do not nevertheless say I hear distance, in like manner
 
 266 GEORGE BERKELEY 
 
 as I say that I see it the ideas perceived by hearing not 
 being so apt to be confounded with the ideas of touch as those 
 of sight are. So likewise a man is easily convinced that bodies 
 and external things are not properly the object of hearing, but 
 only sounds, by the mediation whereof the idea of this or that 
 body, or distance, is suggested to his thoughts. But then one 
 is with more difficulty brought to discern the difference there is 
 betwixt the ideas of sight and touch: though it be certain, a 
 man no more sees and feels the same thing, than he hears and 
 feels the same thing. 
 
 48. One reason of which seems to be this. It is thought a 
 great absurdity to imagine that one and the same thing should 
 have any more than one extension and one figure. But, the 
 extension and figure of a body being let into the mind two ways, 
 and that indifferently, either by sight or touch, it seems to fol- 
 low that we see the same extension and the same figure which 
 we feel. 
 
 49. But, if we take a close and accurate view of the matter, 
 it must be acknowledged that we never see and feel one and the 
 same object. That which is seen is one thing, and that which is 
 felt is another. If the visible figure and extension be not the 
 same with the tangible figure and extension, we are not to infer 
 that one and the same thing has divers extensions. The true 
 consequence is that the objects of sight and touch are two dis- 
 tinct things. It may perhaps require some thought rightly to 
 conceive this distinction. And the difficulty seems not a little 
 increased, because the combination of visible ideas hath con- 
 stantly .the same name as the combination of tangible ideas 
 wherewith it is connected which doth of necessity arise from 
 the use and end of language. 
 
 50. In order, therefore, to treat accurately and unconfusedly 
 of vision, we must bear in mind that there are two sorts of 
 objects apprehended by the eye the one primarily and 
 immediately, the other secondarily and by intervention of the 
 former. Those of the first sort neither are nor appear to be 
 without the mind, or at any distance off. They may, indeed, 
 grow greater or smaller, more confused, or more clear, or more
 
 A NEW THEORY OF VISION 267 
 
 faint. But they do not, cannot approach or recede from us. 
 Whenever we say an object is at a distance, whenever we say 
 it draws near, or goes farther off, we must always mean it of 
 the latter sort, which properly belong to the touch, and are not 
 so truly perceived as suggested by the eye, in like manner as 
 thoughts by the ear. 
 
 51. No sooner do we hear the words of a familiar language 
 pronounced in our ears but the ideas corresponding thereto 
 present themselves to our minds: in the very same instant 
 the sound and the meaning enter the understanding : so closely 
 are they united that it is not in our power to keep out the one 
 except we exclude the other also. We even act in all respects 
 as if we heard the very thoughts themselves. So likewise the 
 secondary objects, or those which are only suggested by sight, 
 do often more strongly affect us, and are more regarded, than 
 the proper objects of that sense; along with which they enter 
 into the mind, and with which they have a far more strict 
 connexion than ideas have with words. Hence it is we find it 
 so difficult to discriminate between the immediate and mediate 
 objects of sight, and are so prone to attribute to the former 
 what belongs only to the latter. They are, as it were, most 
 closely twisted, blended, and incorporated together. And the 
 prejudice is confirmed and riveted in our thoughts by a long 
 tract of time, by the use of language, and want of reflection. 
 However, I doubt not but any one that shall attentively con- 
 sider what we have already said, and shall say upon this sub- 
 ject before we have done (especially if he pursue it in his own 
 thoughts), may be able to deliver himself from that prejudice. 
 Sure I am, it is worth some attention to whoever would under- 
 stand the true nature of vision. 
 
 52. I have now done with distance, and proceed to shew 
 how it is that we perceive by sight the Magnitude of objects. 
 It is the opinion of some that we do it by angles, or by angles 
 in conjunction with distance. But, neither angles nor distance 
 being perceivable by sight, and the things we see being in truth 
 at no distance from us, it follows that, as we have shewn lines
 
 268 GEORGE BERKELEY 
 
 and angles not to be the medium the mind makes use of in 
 apprehending the apparent place, so neither are they the 
 medium whereby it apprehends the apparent magnitude of 
 objects. 
 
 53. It is well known that the same extension at a near dis- 
 tance shall subtend a greater angle, and at a farther distance a 
 lesser angle. And by this principle (we are told) the mind esti- 
 mates the magnitude of an object, comparing the angle under 
 which, it is seen with its distance, and thence inferring the 
 magnitude thereof. What inclines men to this mistake (beside 
 the humour of making one see by geometry) is, that the same 
 perceptions or ideas which suggest distance do also suggest 
 magnitude. But, if we examine it, we shall find they suggest 
 the latter as immediately as the former. I say, they do not first 
 suggest distance and then leave it to the judgment t9 use that 
 as a medium whereby to collect the magnitude; but they have 
 as close and immediate a connexion with the magnitude as with 
 the distance; and suggest magnitude as independently of dis- 
 tance, as they do distance independently of magnitude. All 
 which will be evident to whoever considers what has been 
 already said and what follows. 
 
 54. It has been shown there are two sorts of objects -appre- 
 hended by sight, each whereof has its distinct magnitude, or 
 extension the one, properly tangible, i.e. to be perceived and 
 measured by touch, and not immediately falling under the 
 sense of seeing; the other, properly and immediately visible, 
 by mediation of which the former is brought in view. Each 
 of these magnitudes are greater or lesser, according as they 
 contain in them more or fewer points, they being made up of 
 points or minimums. For, whatever may be said of extension 
 in abstract, it is certain sensible extension is not infinitely divi- 
 sible. There is a minimum tangibile, and a minimum visibile, 
 beyond which sense cannot perceive. This every one's experi- 
 ence will inform him. 
 
 55. The magnitude of the object which exists without the 
 mind, and is at a distance, continues always invariably the 
 same: but, the visible object still changing as you approach
 
 to or recede from the tangible object, it hath no fixed and deter- 
 minate greatness. Whenever therefore we speak of the magni- 
 tude of any thing, for instance a tree or a house, we must mean 
 the tangible magnitude; otherwise. there can be nothing steady 
 and free from ambiguity spoken of it. Now, though the tangi- 
 ble and visible magnitude do in truth belong to two distinct 
 objects, I shall nevertheless (especially since those objects are 
 called by the same name, and are observed to coexist), to avoid 
 tediousness and singularity of speech, sometimes speak of them 
 as belonging to one and the same thing. 
 
 56. Now, in order to discover by what means the magni- 
 tude of tangible objects is perceived by sight, I need only reflect 
 on what passes in my own mind, and observe what those things 
 be which introduce the ideas of greater or lesser into my 
 thoughts, when I look on any object. And these I find to be, 
 first, the magnitude or extension of the visible object, which, 
 being immediately perceived by sight, is connected with that 
 other which is tangible and placed at a distance : secondly, the 
 confusion or distinctness: and thirdly, the vigorousness of faint- 
 ness of the aforesaid visible appearance. Ctzteris paribus, by 
 how much the greater or lesser the visible object is, by so much 
 the greater or lesser do I conclude the tangible object to be. 
 But, be the idea immediately perceived by sight never so large, 
 yet, if it be withal confused, I judge the magnitude of the thing 
 to be but small. If it be distinct and clear, I judge it greater. 
 And, if it be faint, I apprehend it to be yet greater. . . . 
 
 57. Moreover, the judgments we make of greatness do, in 
 like manner as those of distance, depend on the disposition of 
 the eye; also on the figure, number,, and situation of inter- 
 mediate objects, and other circumstances that have been ob- 
 served to attend great or small tangible magnitudes. Thus, 
 for instance, the very same quantity of visible extension which 
 in the figure of a tower doth suggest the idea of great magni- 
 tude shall in the figure of a man suggest the idea of much smaller 
 magnitude. That this is owing to the experience we have had 
 of the usual bigness of a tower and a man, no one, I suppose, 
 need be told.
 
 270 GEORGE BERKELEY 
 
 58. It is also evident that confusion or faintness have no 
 more a necessary connexion with little or great magnitude 
 than they have with little or great distance. As they suggest 
 the latter, so they suggest the former to our minds. And, by 
 consequence, if it were not for experience, we should no more 
 judge a faint or confused appearance to be connected with 
 great or little magnitude than we should that it was connected 
 with great or little distance. 
 
 63. Moreover, it is not only certain that any idea of sight 
 might not have been connected with this or that idea of touch 
 we now observe to accompany it, but also that the greater 
 visible magnitudes might have been connected with and 
 introduced into our minds lesser tangible magnitudes, and 
 the lesser visible magnitudes greater tangible magnitudes. 
 Nay, that it actually is so, we have daily experience that 
 object which makes a strong and large appearance not seem- 
 ing near so great as another the visible magnitude whereof is 
 much less, but more faint, and the appearance upper, or which 
 is the same thing, painted lower on the retina, which faintness 
 and situation suggest both greater magnitude and greater 
 distance. 
 
 64. From which, and from sect. 57 and 58, it is manifest 
 that, as we do not perceive the magnitude of objects immedi- 
 ately by sight, so neither do we perceive them by the media- 
 tion of anything which has a necessary connexion with them. 
 Those ideas that now suggest unto us the various magnitudes 
 of external objects before we touch them might possibly have 
 suggested no such thing; or they might have signified them 
 in a direct contrary manner, so that the very same ideas on 
 the perception whereof we judge an object to be small might 
 as well have served to make us conclude it great; those 
 ideas being in their own nature equally fitted to bring into 
 our minds the idea of small or great, or no size at all, of outward 
 objects, just as the words of any language are in their own 
 nature indifferent to signify this or that thing, or nothing at all. 
 
 65. As we see distance so we see magnitude. And we see 
 both in the same way that we see shame or anger in the looks
 
 A NEW THEORY OF VISION 271 
 
 of a man. Those passions are themselves invisible; they are 
 nevertheless let in by the eye along with colours and altera- 
 tions of countenance which are the immediate object of vision, 
 and which signify them for no other reason than barely because 
 they have been observed to accompany them. Without which 
 experience we should no more have taken blushing for a sign 
 of shame than of gladness. 
 
 66. We are nevertheless exceedingly prone to imagine those 
 things which are perceived only by the mediation of others to 
 be themselves the immediate objects of sight, or at least to 
 have in their own nature a fitness to be suggested by them 
 before ever they had been experienced to coexist with them. 
 From which prejudice every one perhaps will not find it easy 
 to emancipate * himself , by any the clearest convictions of 
 reason. And there are some grounds to think that, if there 
 was one only invariable and universal language in the world, 
 and that men were born with the faculty of speaking it, it 
 would be the opinion of some, that the ideas in other men's 
 minds were properly perceived by the ear, or had at least a 
 necessary and inseparable tie with the sounds which were 
 affixed to them. All which seems to arise from want of a due 
 application of our discerning faculty, thereby to discriminate 
 between the ideas that are in our understandings, and consider 
 them apart from each other; which would preserve us from 
 confounding those that are different, and make us see what 
 ideas do, and what do not, include or imply this or that other 
 idea. 
 
 77. pFor the further clearing up of this point, it is to be 
 observed, that what we immediately and properly see are only 
 lights and colours in sundry situations and shades, and degrees 
 of faintness and clearness, confusion and distinctness. All 
 which visible objects are only in the mind; nor do they suggest 
 aught external, whether distance or magnitude, otherwise than 
 by habitual connexion, as words do things. We are also to 
 remark, that beside the straining of the eyes, and beside the 
 
 1 What follows in this section is not in the first edition.
 
 272 GEORGE BERKELEY 
 
 vivid and faint, the instinct and confused appearances (which, 
 bearing some proportion to lines and angles, have been sub- 
 stituted instead of them in the foregoing part of this Treatise), 
 there are other means which suggest both distance and magni- 
 tude particularly the situation of visible points or objects, 
 as upper or lower; the former suggesting a farther distance and 
 greater magnitude, the latter a nearer distance and lesser mag- 
 nitude all which is an effect only of custom and experience, 
 there being really nothing intermediate in the line of distance 
 between the uppermost and the lowermost, which are both 
 equidistant, or rather at no distance from the eye; as there is 
 also nothing in upper or lower which by necessary connexion 
 should suggest greater or lesser magnitude. Now, as these cus- 
 tomary experimental means of suggesting distance do likewise 
 suggest magnitude, so they suggest the one as immediately as 
 the other. I say, they do not (Vid. sect. 53) first suggest dis- 
 tance, and then leave the mind from thence to infer or compute 
 magnitude, but suggest magnitude as immediately and directly 
 as they suggest distance.] 
 
 78. This phenomenon of the horizontal moon is a clear 
 instance of the insufficiency of lines and angles for explaining 
 the way wherein the mind perceives and estimates the magni- 
 tude of outward objects. There is, nevertheless, a use of com- 
 putation by them in order to determine the apparent mag- 
 nitude of things, so far as they have a connexion with and are 
 proportional to those other ideas or perceptions which are the 
 true and immediate occasions that suggest to the mind the 
 apparent magnitude of things. But this in general may, I 
 think, be observed concerning mathematical computation in 
 optics that it can never be very precise and exact, since the 
 judgments we make of the magnitude of external things do 
 often depend on several circumstances which are not propor- 
 tional to or capable of being defined by lines and angles. 
 
 79. From what has been said, we may safely deduce this 
 consequence, to wit, that a man born blind, and made to see, 
 would, at first opening of his eyes, make a very different judg- 
 ment of the magnitude of objects intromitted by them from
 
 A NEW THEORY OF VISION 273 
 
 what others do. He would not consider the ideas of sight with 
 reference to, or as having any connexion with the idea of touch. 
 His view of them being entirely terminated within themselves, 
 he can no otherwise judge them great or small than as they 
 contain a greater or lesser number of visible points. Now, it 
 being certain that any visible point can cover or exclude from 
 view only one other visible point, it follows that whatever 
 object intercepts the view of another hath an equal number 
 of visible points with it; and, consequently, they shall both 
 be thought by him to have the same magnitude. Hence, it is. 
 evident one in those circumstances would judge his thumb, 
 with which he might hide a tower, or hinder its being seen, equal 
 to that tower; or his hand, the interposition whereof might con- 
 ceal the firmament from his view, equal to the firmament: how 
 great an inequality soever there may, in our apprehensions, 
 seem to be betwixt those two things, because of the customary 
 and close connexion that has grown up in our minds between 
 the objects of sight and touch, whereby the very different and 
 distinct ideas of those two senses are so blended and con- 
 founded together as to be mistaken for one and the same thing 
 out of which prejudice we cannot easily extricate ourselves. 
 
 127. It having been shewn that there are no abstract ideas 
 of figure, and that it is impossible for us, by any precision of 
 thought, to frame an idea o extension separate from all other 
 visible and tangible qualities, which shall be common both to 
 sight and touch the question now rem'aining is, Whether 
 the particular extensions, figures, and motions perceived by 
 sight, be of the same kind with the particular extensions, figures, 
 and motions perceived by touch? In answer to which I shall 
 venture to lay down the following proposition: The exten- 
 sion, figures, and motions perceived by sight are specifically dis- 
 tinct from the ideas of touch, called by the same names; nor is there 
 any such thing as one idea, or kind of idea, common to both 
 senses. This proposition may, without much difficulty, be col- 
 lected from what hath been said in several places of this Essay. 
 But, because it seems so remote from, and contrary to the
 
 274 GEORGE BERKELEY 
 
 received notions and settled opinion of mankind, I shall at- 
 tempt to demonstrate it more particularly and at large by the 
 following arguments: - 
 
 128. First, When, upon perception of an idea, I range it 
 under this or that sort, it is because it is perceived after the 
 same manner, or because it has likeness or conformity with, 
 or affects me in the same way as the ideas of the sort I rank 
 it under. In short, it must not be entirely new, but have some- 
 thing in it old and already perceived by me. It must, I say, 
 have so much, at least, in common with the ideas I have before 
 known and named, as to make me give it the same name with 
 them. But, it has been, if I mistake not, clearly made out that 
 a man born blind would not, at first reception of his sight, think 
 the things he saw were of the same nature with the objects of 
 touch, or had anything in common with them ; but that they 
 were a new set of ideas, perceived in a new manner, and en- 
 tirely different from all he had ever perceived before. So that 
 he would not call them by the same name, nor repute them 
 to be of the same sort, with anything he had hitherto known. 
 
 129. Secondly, Light and colours are allowed by all to con- 
 stitute a sort or species entirely different from the ideas of 
 touch; nor will any man, I presume, say they can make them- 
 selves perceived by that sense. But there is no other immediate 
 object of sight besides light and colours. It is therefore a direct 
 consequence, that there is no idea common to both senses. 
 
 130. It is a prevailing opinion, even amongst these who 
 have thought and writ most accurately concerning our ideas, 
 and the ways whereby they enter into the understanding, that 
 something more is perceived by sight than barely light and 
 colours with their variations. Mr. Locke termeth sight 'the 
 most comprehensive of all our senses, conveying to our minds 
 the ideas of light and colours, which are peculiar only to that 
 sense; and also the far different ideas of space, figure, and 
 motion.' (Essay on Human Understanding, b. II. ch. 9. s. 9.) 
 Space or distance, we have shewn, is no otherwise the object 
 of sight than of hearing. (Vid. sect. 46.) And, as for figure 
 and extension, I leave it to any one that shall calmly attend
 
 A NEW THEORY OF VISION 275 
 
 to his own clear and distinct ideas to decide whether he had 
 any idea intromitted immediately and properly by sight save 
 only light and colours: or, whether it be possible for him to 
 frame in his mind a distinct abstract idea of visible extension, or 
 figure, exclusive of all colour; and, on the other hand, whether 
 he can conceive colour without visible extension? For my 
 own part, I must confess, I am not able to attain so great a 
 nicety of abstraction. I know very well that, in a strict sense, 
 I see nothing but light and colours, with their several shades 
 and variations. He who beside these doth also perceive by 
 sight ideas far different and distinct from them, hath that 
 faculty in a degree more perfect and comprehensive than I can 
 pretend to. It must be owned, indeed, that, by the mediation 
 of light and colours, other far different ideas are suggested to my 
 mind. But then, upon this score, I see no reason why sight 
 should be thought more 'comprehensive' than the hearing, 
 which, beside sounds which are peculiar to that sense, doth, by 
 their mediation, suggest not only space, figure, and motion, but 
 also all other ideas whatsoever that can be signified by words. 
 131. Thirdly, It is, I think, an axiom universally received, 
 that ' quantities of the same kind may be added together and 
 make one entire sum.' Mathematicians add lines together; but 
 they do not add a line to a solid, or conceive it as making one 
 sum with a surface. These three kinds of quantity being 
 thought incapable of any such mutual addition, and conse- 
 quently of being compared together in the several ways of 
 proportion, are by them for that reason esteemed entirely 
 disparate and heterogeneous. Now let any one try in his 
 thoughts to add a "visible line or surface to a tangible line or 
 surface, so as to conceive them making one continued sum or 
 whole. He that can do this may think them homogeneous; 
 but he that cannot must, by the foregoing axiom, think them 
 heterogeneous. A blue and a red line I can conceive added 
 together into one sum and making one continued line; but, 
 to make, in my thoughts, one continued line of a visible and 
 tangible line added together, is, I find, a task far more diffi- 
 cult, and even insurmountable and I leave it to the reflec-
 
 276 GEORGE BERKELEY 
 
 tion and experience of every particular person to determine for 
 himself. 
 
 132. A farther confirmation of our tenet may be drawn 
 from the solution of Mr. Molyneux's problem, published by 
 Mr. Locke in his Essay: which I shall set down as it there lies, 
 together with Mr. Locke's opinion of it: 'Suppose a man 
 born blind, and now adult, and taught by his touch to distin- 
 guish between a cube and a sphere of the same metal, and 
 nighly of the same bigness, so as to tell when he felt one and 
 the other, which is the cube, and which the sphere. Suppose 
 then the cube and sphere placed on a table, and the blind man 
 made to see: Quaere, Whether by his sight, before he touched 
 them, he could now distinguish, and tell, which is the globe, 
 which the cube. To which the acute and judicious proposer 
 answers: Not. For, though he has obtained the experience of 
 how a globe, how a cube affects his touch; yet he has not yet 
 attained the experience, that what affects his touch so or so 
 must affect his sight so or so: or that a protuberant angle in the 
 cube, that pressed his hand unequally, shall appear to his eye 
 as it doth in the cube. I agree with this thinking gentleman, 
 whom I am proud to call my friend, in his answer to this his 
 problem; and am of opinion that the blind man, at first sight, 
 would not be able with certainty to say, which was the globe, 
 which the cube, whilst he only saw them.' (Locke's Essay on 
 Human Understanding, b. II. ch. 9. s. 8. 1 ) 
 
 133. Now, if a square surface perceived by touch be of the 
 same sort with a square surface perceived by sight, it is certain 
 the blind man here mentioned might know a square surface 
 as soon as he saw it. It is no more but introducing into his 
 mind, by a new inlet, an idea he has been already well ac- 
 quainted with. Since therefore he is supposed to have known 
 by his touch that a cube is a body terminated by square sur- 
 faces; and that a sphere is not terminated by square surfaces 
 upon the supposition that a visible and tangible square differ 
 only in numero, it follows that he might know, by the unerring 
 
 1 See Leibnitz (Nouveaux Essais, liv. II. ch. 9), who disputes the alleged 
 heterogeneity.
 
 A NEW THEORY OF VISION 277 
 
 mark of the square surfaces, which was the cube, and which not, 
 while he only saw them. We must therefore allow, either that 
 visible extension and figures are specifically distinct from tangi- 
 ble extension and figures, or else, that the solution of this prob- 
 lem, given by those two thoughtful and ingenious men, is 
 wrong. 
 
 134. Much more might be laid together in proof of the pro- 
 position I have advanced. But, what has been said is, if I mis- 
 take not, sufficient to convince any one that shall yield a 
 reasonable attention. And, as for those that will not be at the 
 pains of a little thought, no multiplication of words will ever 
 suffice to make them understand the truth, or rightly conceive 
 my meaning. 
 
 135. I cannot let go the above-mentioned problem without 
 some reflection on it. It hath been made evident that a man 
 blind from his birth would not, at first sight, denominate any- 
 thing he saw, by the names he had been used to appropriate 
 to ideas of touch. (Vid. sect. 106.) Cube, sphere, table are 
 words he has known applied to things perceivable by touch, 
 but to things perfectly intangible he never knew them applied. 
 Those words, in their wonted application, always marked out 
 to his mind bodies or solid things which were perceived by the 
 resistance they gave. But there is no solidity, no resistance or 
 protrusion, perceived by sight. In short, the ideas of sight are 
 all new perceptions, to which there be no names annexed in his 
 mind ; he cannot therefore understand what is said to him con- 
 cerning them. And, to ask of the two bodies he saw placed on 
 the table, which was the sphere, which the cube, were to him a 
 question downright bantering and unintelligible; nothing he 
 sees being able to suggest to his thoughts the idea of body, dis- 
 tance, or, in general, of anything he had already known. 
 
 136. It is a mistake to think the same thing affects both 
 sight and touch. If the same angle or square which is the 
 object of touch be also the object of vision, what should hinder 
 the blind man, at first sight, from knowing it? For, though 
 the manner wherein it affects the sight be different from that 
 wherein it affected his touch, yet, there being, beside this man-
 
 278 GEORGE BERKELEY 
 
 ner of circumstance, which is new and unknown, the angle or 
 figure, which is old and known, he cannot choose but discern it. 
 
 147. Upon the whole, I think we may fairly conclude that 
 the prope'r objects of vision constitute the Universal Language 
 of Nature, whereby we are instructed how to regulate our 
 actions, in order to attain those things that are necessary to 
 the preservation and well-being of our bodies, as also to avoid 
 whatever may be hurtful and destructive of them. It is by their 
 information that we are principally guided in all the transac- 
 tions and concerns of life. And the manner wherein they sig- 
 nify and mark out unto us the objects which are at a distance 
 is the same with that of languages and signs of human appoint- 
 ment; which do not suggest the things signified by any likeness 
 or identity of nature, but only by an habitual connexion that 
 experience has made us to observe between them. 
 
 148. Suppose one who had always continued blind be told 
 by his guide that after he has advanced so many steps he 
 shall come to the brink of a precipice, or be stopped by a wall; 
 must not this to him seem very admirable and surprising? 
 He cannot conceive how it is possible for mortals to frame such 
 predictions as these, which to him would seem as strange and 
 unaccountable as prophecy does to others. Even they who 
 are blessed with the visive faculty may (though familiarity 
 make it less observed) find therein sufficient cause of admira- 
 tion. The wonderful art and contrivance wherewith it is ad- 
 justed to those ends and purposes for which it was apparently 
 designed ; the vast extent, number, and variety of objects that 
 are at once, with so much ease, and quickness, and pleasure, 
 suggested by it all these afford subject for much and pleasing 
 speculation, and may, if anything, give us some glimmering 
 analogous praenotion of things, that are placed beyond the 
 certain discovery and comprehension of our present state.
 
 DAVID HUME 
 
 (1711-1766) 
 
 A TREATISE OF HUMAN NATURE* 
 BOOK I. OF THE UNDERSTANDING 
 
 PART I. OF IDEAS, THEIR ORIGIN, COMPOSITION, 
 CONNEXION, &-C. 
 
 SECTION I. OF THE ORIGIN OF OUR IDEAS 
 
 ALL the perceptions of the human mind resolve themselves 
 into two distinct kinds, which I shall call IMPRESSIONS and 
 IDEAS. The difference betwixt these consists in the degrees 
 of force and liveliness with which they strike upon the mind, 
 and make their way into our thought or consciousness. Those 
 perceptions, which enter with most force and violence, we may 
 name impressions; and under this name I comprehend all our 
 sensations, passions and emotions, as they make their first 
 appearance in the soul. By ideas I mean the faint images of 
 these in thinking and reasoning; such as, for instance, are all 
 the perceptions excited by the present discourse, excepting only 
 those which arise from the sight and touch, and excepting the 
 immediate pleasure or uneasiness it may occasion. I believe it 
 will not be very necessary to employ many words in explaining 
 this distinction. Every one of himself will readily perceive the 
 difference betwixt feeling and thinking. The common degrees 
 of these are easily distinguished; tho' it is not impossible but 
 in particular instances they may very nearly approach to each 
 other. Thus in sleep, in a fever, in madness, or in any very 
 
 * London, 1739-40; ib., 1817; edit, with analytical index by T. Selby-Bigge, 
 Oxford, 1888; edit, with preliminary dissertations and notes byT. H. Green and 
 T. H. Grose, 2 vols., Lond., 1874; new ed. ib., 1888.
 
 2 8o DAVID HUME 
 
 violent emotions of soul, our ideas may approach to our im- 
 pressions: As on the other hand it sometimes happens, that our 
 impressions are so faint and low, that we cannot distinguish 
 them from our ideas. But notwithstanding this near resem- 
 blance in a few instances, they are in general so very different, 
 that no-one can make a scruple to rank them under distinct 
 heads, and assign to each a peculiar name to mark the differ- 
 ence. 1 
 
 There is another division of our perceptions, which it will 
 be convenient to observe, and which extends itself both to our 
 impressions and ideas. This division is into SIMPLE and COM- 
 PLEX. Simple perceptions or impressions and ideas are such as 
 admit of no distinction or separation. The complex are the 
 contrary to these, and may be distinguished into parts. Tho' 
 a particular colour, taste, and smell are qualities all united 
 together in this apple, 't is easy to perceive they are not the 
 same, but are at least distinguishable from each other. 
 
 Having by these divisions given an order and arrangement 
 to our objects, we may now apply ourselves to consider with 
 the more accuracy their qualities and relations. The first cir- 
 cumstance, that strikes my eye, is the great resemblance 
 betwixt our impressions and ideas in every other particular, 
 except their degree of force and vivacity. The one seem to be 
 in a manner the reflexion of the other; so that all the percep- 
 tions of the mind are double, and appear both as impressions 
 and ideas. Wh^n I shut my eyes and think of my chamber, the 
 ideas I form are exact representations of the impressions I felt ; 
 nor is there any circumstance of the one, which is not to be found 
 in the other. In running over my other perceptions, I find still 
 the same resemblance and representation. Ideas and impres- 
 sions appear always to correspond to each other. This circum- 
 
 1 I here make use of these terms, impression and idea, in a sense different from 
 what is usual, and I hope this liberty will be allowed me. Perhaps I rather restore 
 the word, idea, to its original sense, from which Mr. Locke had perverted it, in 
 making it stand for all our perceptions. By the term of impression I would not be 
 understood to express the manner, in which our lively perceptions are produced 
 in the eoul, but merely the perceptions themselves; for which there is no particu- 
 lar name either in the English or any other language, that I know of.
 
 A TREATISE OF HUMAN NATURE 281 
 
 stance seems to me remarkable, and engages my attention for 
 a moment. 
 
 Upon a more accurate survey I find I have been carried away 
 too far by the first appearance, and that I must make use of the 
 distinction of perceptions into simple and complex, to limit this 
 general decision, that all our ideas and impressions are resem- 
 bling. I observe, that many of our complex ideas never had 
 impressions, that corresponded to them, and that many of our 
 complex impressions never are exactly copied in ideas. I can 
 imagine to myself such a city as the New Jerusalem, whose 
 pavement is gold and walls are rubies, tho' I never saw any 
 such. I have seen Paris; but shall I affirm I can form such an 
 idea of that city, as will perfectly represent all its streets and 
 houses in their real and just proportions? 
 
 I perceive, therefore, that tho' there is in general a great 
 resemblance betwixt our complex impressions and ideas, yet 
 the rule is not universally true, that they are exact copies of 
 each other. We may next consider how the case stands with 
 our simple perceptions. After the most accurate examination, 
 of which I am capable, I venture to affirm, that the rule here 
 holds without any exception, and that every simple idea has a 
 simple impression, which resembles it; and every simple impres- 
 sion a correspondent idea. That idea of red, which we form in 
 the dark, and that impression, which strikes our eyes in sun- 
 shine, differ only in degree, not in nature. That the case is the 
 same with all our simple impressions and ideas, 't is impossible 
 to prove by a particular enumeration of them. Every one may 
 satisfy himself in this point by running over as many as he 
 pleases. But if any one should deny this universal resemblance, 
 I know no way of convincing him, but by desiring him to shew 
 a simple impression, that has not a correspondent idea, or a 
 simple idea, that has not a correspondent impression. If he 
 does not answer this challenge, as 't is certain he cannot, we 
 may from his silence and our own observation establish our 
 conclusion. 
 
 Thus we find, that all simple ideas and impressions resem- 
 ble each other; and as the complex are formed from them, we
 
 282 DAVID HUME 
 
 may affirm in general, that these two species of perception are 
 exactly correspondent. Having discover'd this relation, which 
 requires no farther examination, I am curious to find some 
 other of their qualities. Let us consider how they stand with 
 regard to their existence, and which of the impressions and 
 ideas are causes, and which effects. 
 
 The full examination of this question is the subject of the 
 present treatise; and therefore we shall here content ourselves 
 with establishing one general proposition, That all our simple 
 ideas in their first appearance are derived from simple impressions, 
 which are correspondent to them, and which they exactly represent. 
 
 In seeking for phenomena to prove this proposition, I find 
 only those of two kinds; but in each kind the phenomena are 
 obvious, numerous, and conclusive. I first make myself cer- 
 tain, by a new review, of what I have already asserted, that 
 every simple impression is attended with a correspondent idea, 
 and every simple idea with a correspondent impression. From 
 this constant conjunction of resembling perceptions I immedi- 
 ately conclude, that there is a great connexion betwixt our cor- 
 respondent impressions and ideas, and that the existence of the 
 one has a considerable influence upon that of the other. Such a 
 constant conjunction, in such an infinite number of instances, 
 can never arise from chance ; but clearly proves a dependence 
 of the impressions on the ideas, or of the ideas on the impres- 
 sions. That I may know on which side this dependence lies, 
 I consider the order of their first appearance; and find by con- 
 stant experience, that the simple impressions always take the 
 precedence of their correspondent ideas, but never appear in 
 the contrary order. To give a child an idea of scarlet or orange, 
 of sweet or bitter, I present the objects, or in other words, con- 
 vey to him these impressions; but proceed not so absurdly, as 
 to endeavour to produce the impressions by exciting the ideas. 
 Our ideas upon their appearance produce not their correspond- 
 ent impressions, nor do we perceive any colour, or feel any sen- 
 sation merely upon thinking of them. On the other hand we find 
 that any impression either of the mind or body is constantly 
 followed by an idea, which resembles it, and is only different
 
 A TREATISE OF HUMAN NATURE 283 
 
 in the degrees of force and liveliness. The constant conjunction 
 of our resembling perceptions, is a convincing proof, that the 
 one are the causes of the other; and this priority of the impres- 
 sions is an equal proof, that our impressions are the causes of 
 our ideas, not our ideas of our impressions. 
 
 To confirm this I consider another plain and convincing 
 phenomenon; which is, that where-ever by any accident the 
 faculties, which give rise to any impressions, are obstructed 
 in their operations, as when one is born blind or deaf; not only 
 the impressions are lost, but also their correspondent ideas; 
 so that there never appear in the mind the least traces of either 
 of them. Nor is this only true, where the organs of sensation are 
 entirely destroy'd, but likewise where they have never been put 
 in action to produce a particular impression. We cannot form 
 to ourselves a just idea of the taste of a pine-apple, without 
 having actually tasted it. 
 
 There is however one contradictory phaenomenon, which 
 may prove, that 't is not absolutely impossible for ideas to go 
 before their correspondent impressions. I believe it will readily 
 be allow'd, that the several distinct ideas of colours, which 
 enter by the eyes, or those of sounds, which are convey'd by 
 the hearing, are really different from each other, tho' at the 
 same time resembling. Now if this be true of different colours, 
 it must be no less so of the different shades of the same colour, 
 that each of them produces a distinct idea, independent of the 
 rest. For if this shou'd be deny'd, 't is possible, by the con- 
 tinual gradation of shades, to run a colour insensibly into what 
 is most remote from it; and if you will not allow any of the 
 means to be different, you cannot without absurdity deny the 
 extremes to be the same. Suppose therefore a person to have 
 enjoyed his sight for thirty years, and to have become per- 
 fectly well acquainted with colours of all kinds, excepting one 
 particular shade of blue, for instance, which it never has been 
 his fortune to meet with. Let all the different shades of that 
 colour, except that single one, be plac'd before him, descending 
 gradually from the deepest to the lightest; 't is plain, that he 
 will perceive a blank, where that shade is wanting, and will be
 
 284 DAVID HUME 
 
 sensible, that there is a greater distance in that place betwixt 
 the contiguous colours, than in any other. Now I ask, whether 
 't is possible for him, from his own imagination, to supply this 
 deficiency, and raise up to himself the idea of that particular 
 shade, tho' it had never been conveyed to him by his senses? 
 I believe there are few but will be of opinion that he can ; and 
 this may serve as a proof, that the simple ideas are not always 
 derived from the correspondent impressions; tho' the instance 
 is so particular and singular, that 't is scarce worth our observ- 
 ing, and does not merit that for it alone we should alter our 
 general maxim. 
 
 But besides this exception, it may not be amiss to remark 
 on this head, that the principle of the priority of impressions 
 to ideas must be understood with another limitation, viz. that 
 as our ideas are images of our impressions, so we can form 
 secondary ideas, which are images of the primary; as appears 
 from this very reasoning concerning them. This is not, pro- 
 perly speaking, an exception to the rule so much as an explana- 
 tion of it. Ideas produce the images of themselves in new ideas; 
 but as the first ideas are supposed to be derived from impres- 
 sions, it still remains true, that all our simple ideas proceed 
 either mediately or immediately from their correspondent 
 impressions. 
 
 This then is the first principle I establish in the science of 
 human nature; nor ought we to despise it because of the sim- 
 plicity of its appearance. For 't is remarkable, that the present 
 question concerning the precedency of our impressions or ideas, 
 is the same with what has made so much noise in other terms, 
 when it has been disputed whether there be any innate ideas, 
 or whether all ideas be derived from sensation and reflexion. 
 We may observe, that in order to prove the ideas of extension 
 and colour not to be innate, philosophers do nothing but 
 shew, that they are conveyed by our senses. To prove the 
 ideas of passion and desire not to be innate, they observe that 
 we have a preceding experience of these emotions in ourselves. 
 Now if we carefully examine these arguments, we shall find that 
 they prove nothing but that ideas are preceded by other more
 
 A TREATISE OF HUMAN NATURE 285 
 
 lively perceptions, from which they are derived, and which they 
 represent. I hope this clear stating of the question will remove 
 all disputes concerning it, and will render this principle of more 
 use in our reasonings, than it seems hitherto to have been. 
 
 SECTION II. DIVISION OF THE SUBJECT 
 
 SINCE it appears, that our simple impressions are prior to 
 their correspondent ideas, and that the exceptions are very 
 rare, method seems to require we should examine our impres- 
 sions, before we consider our ideas. Impressions may be di- 
 vided into two kinds, those of SENSATION and those of REFLEX- 
 ION. The first kind arises in the soul originally, from unknown 
 causes. The second is derived in a great measure from our 
 ideas, and that in the following order. An impression first 
 strikes upon the senses, and makes us perceive heat or cold, 
 thirst or hunger, pleasure or pain of some kind or other. Of 
 this impression there is a copy taken by the mind, which re- 
 mains after the impression ceases; and this we call an idea. 
 This idea of pleasure or pain, when it returns upon the soul, 
 produces the new impressions of desire and aversion, hope and 
 fear, which may properly be called impressions of reflection, 
 because derived from it. These again are copied by the memory 
 and imagination, and become ideas; which perhaps in their turn 
 give rise to other impressions and ideas. So that the impres- 
 sions of reflection are only antecedent to their correspondent 
 ideas; but posterior to those of sensation, and deriv'd from 
 them. The examination of our sensations belongs more to 
 anatomists and natural philosophers than to moral ; and there- 
 fore shall not at present be enter'd upon. And as the impres- 
 sions of reflection, viz. passions, desires, and emotions, which 
 principally deserve our attention, arise mostly from ideas, 't will 
 be necessary to reverse that method, which at first sight seems 
 most natural ; and in order to explain the nature and principles 
 of the human mind, give a particular account of ideas, before 
 we proceed to impressions. For this reason I have here chosen 
 to begin with ideas.
 
 286 DAVID HUME 
 
 SECTION III. OF THE IDEAS OF THE MEMORY AND IMAGINA- 
 TION 
 
 WE find by experience, that when any impression has been 
 present with the mind, it again makes its appearance there as 
 an idea; and this it may do after two different ways; either 
 when in its new appearance it retains a considerable degree 
 of its first vivacity, and is somewhat intermediate betwixt an 
 impression and an idea; or when it entirely loses that vivacity, 
 and is a perfect idea. The faculty, by which we repeat our 
 impressions in the first manner, is called the MEMORY, and the 
 other the IMAGINATION. 'T is evident at first sight, that the 
 ideas of the memory are much more lively and strong than 
 those of the imagination, and that the former faculty paints its 
 objects in more distinct colours, than any which are employ 'd 
 by the latter. When we remember any past event, the idea 
 of it flows in upon the mind in a forcible manner; whereas in 
 the imagination the perception is faint and languid, and cannot 
 without difficulty be preserv'd by the mind steady and uni- 
 form for any considerable time. Here then is a sensible differ- 
 ence betwixt one species of ideas and another. But of this more 
 fully hereafter. 1 
 
 There is another difference betwixt these two kinds of ideas, 
 which is no less evident, namely that tho' neither the ideas of 
 the memory nor imagination, neither the lively nor faint ideas 
 can make their appearance in the mind, unless their corre- 
 spondent impressions have gone before to prepare the way for 
 them, yet the imagination is not restrain'd to the same order 
 and form with the original impressions; while the memory is in 
 a manner ty'd down in that respect, without any power of 
 variation. 
 
 'T is evident, that the memory preserves the original form, 
 in which its objects were presented, and that where-ever we 
 depart from it in recollecting any thing, it proceeds from some 
 defect or imperfection in that faculty. An historian may, per- 
 haps, for the more convenient carrying on of his narration, 
 1 Part III. sect. 5.
 
 A TREATISE OF HUMAN NATURE 287 
 
 relate an event before another, to which it was in fact posterior; 
 but then he takes notice of this disorder, if he be exact ; and by 
 that means replaces the idea in its due position. 'T is the same 
 case in our recollection of those places and persons, with which 
 we were formerly acquainted. The chief exercise of the memory 
 is not to preserve the simple ideas, but their order and posi- 
 tion. In short, this principle is supported by such a number of 
 common and vulgar phenomena, that we may spare ourselves 
 the trouble of insisting on it any farther. 
 
 The same evidence follows us in our Second principle, of the 
 liberty of the imagination to transpose and change its ideas. The 
 fables we meet with in poems and romances put this entirely 
 out of question. Nature there is totally confounded, and no- 
 thing mentioned but winged horses, fiery dragons, and mon- 
 strous giants. Nor will this liberty of the fancy appear strange, 
 when we consider, that all our ideas are copy'd from our impres- 
 sions, and that there are not any two impressions which are 
 perfectly inseparable. Not to mention, that this is an evident 
 consequence of the division of ideas into simple and complex. 
 Where-ever the imagination perceives a difference among ideas, 
 it can easily produce a separation. 
 
 SECTION IV. OF THE CONNEXION OR ASSOCIATION OF IDEAS 
 
 As all simple ideas may be separated by the imagination, 
 and may be united again in what form it pleases, nothing wou'd 
 be more unaccountable than the operations of that faculty, 
 were it not guided by some universal principles, which render 
 it, in some measure, uniform with itself in all times and places. 
 Were ideas entirely loose and unconnected, chance alone wou'd 
 join them ; and 't is impossible the same simple ideas should 
 fall regularly into complex ones (as they commonly do) with- 
 out some bond of union among them, some associating quality, 
 by which one idea naturally introduces another. This uniting 
 principle among ideas is not to be consider 'd as an inseparable 
 connexion; for that has been already^ excluded from the imag- 
 ination: Nor yet are we to conclude, that without it the mind
 
 288 DAVID HUME 
 
 cannot join two ideas; for nothing is more free than that 
 faculty: but we are only to regard it as a gentle force, which 
 commonly prevails, and is the cause why, among other things, 
 languages so nearly correspond to each other; nature in a man- 
 ner pointing out to every one those simple ideas, which are 
 most proper to be united into a complex one. The qualities, 
 from which this association arises, and by which the mind is 
 after this manner convey'd from one idea to another, are three, 
 viz. RESEMBLANCE, CONTIGUITY in time or place, and CAUSE 
 and EFFECT. * 
 
 I believe it will not be very necessary to prove, that these 
 qualities produce an association among ideas, and upon the 
 appearance of one idea naturally introduce another. Tis 
 plain, that in the course of our thinking, and in the constant 
 revolution of our ideas, our imagination runs easily from one 
 idea to any other that resembles it, and that this quality alone 
 is to the fancy a sufficient bond and association. 'Tis like- 
 wise evident, that as the senses, in changing their objects, are 
 necessitated to change them regularly, and take them as they 
 lie contiguous to each other, the imagination must by long cus- 
 tom acquire the same method of thinking, and run along the 
 parts of space and time in conceiving its objects. As to the con- 
 nexion, that is made by the relation of cause and e/ect, we shall 
 have occasion afterwards to examine it to the bottom, and 
 therefore shall not at present insist upon it. 'T is sufficient 
 to observe, that there is no relation, which produces a stronger 
 connexion in the fancy, and makes one idea more readily recall 
 another, than the relation of cause and effect betwixt their 
 objects. 
 
 That we may understand the full extent of these relations, 
 we must consider, that two objects are connected together in 
 the imagination, not only when the one is immediately re- 
 sembling, contiguous to, or the cause of the other, but also 
 when there is interposed betwixt them a third object, which 
 bears to both of them any of these relations. This may be 
 carried on to a great length; tho' at the same time we may 
 observe, that each remove considerably weakens the relation.
 
 A TREATISE OF HUMAN NATURE 289 
 
 Cousins in the fourth degree are connected by causation, if I 
 may be allowed to use that term; but not so closely as brothers, 
 much less as child and parent. In general we may observe, that 
 all the relations of blood depend upon cause and effect, and are 
 esteemed near or remote, according to the number of connect- 
 ing causes interpos'd betwixt the persons. 
 
 Of the three relations above-mention'd this of causation is 
 the most extensive. Two objects may be consider'd as plac'd 
 in this relation, as well when one is the cause of any of the 
 actions or motions of the other, as when the former is the 
 cause of the existence of the latter. For as that action or 
 motion is nothing but the object itself, consider'd in a certain 
 light, and as the object continues the same in all its different 
 situations, 't is easy to imagine how such an influence of objects 
 upon one another may connect them in the imagination. 
 
 We may carry this farther, and remark, not only that two 
 objects are connected by the relation of cause and effect, when 
 the one produces a motion or any action in the other, but also 
 when it has a power of producing it. And this we may observe 
 to be the source of all the relations of interest and duty, by 
 which men influence each other in society, and are plac'd in the 
 ties of government and subordination. A master is such-a-one 
 as by his situation, arising either from force or agreement, has 
 a power of directing in certain particulars the actions of another, 
 whom we call servant. A judge is one, who in all disputed cases 
 can fix by his opinion the possession or property of any thing 
 betwixt any members of the society. When a person is pos- 
 sess'd of any power, there is no more required to convert it into 
 action, but the exertion of the will; and that in every case is 
 consider'd as possible, and in many as probable; especially in 
 the case of authority, where the obedience of the subject is a 
 pleasure and advantage to the superior. 
 
 These are therefore the principles of union or cohesion 
 among our simple ideas, and in the imagination supply the 
 place of that inseparable connexion, by which they are united 
 in our memory. Here is a kind of ATTRACTION, which in the 
 mental world will be found to have as extraordinary effects as
 
 290 DAVID HUME 
 
 in the natural, and to shew itself in as many and as various 
 forms. Its effects are every where conspicuous; but as to its 
 causes, they are mostly unknown, and must be resolv'd into 
 original qualities of human nature, which I pretend not to 
 explain. Nothing is more requisite for a true philosopher, than 
 to restrain the intemperate desire of searching into causes, and 
 having establish' d any doctrine upon a sufficient number of 
 experiments, rest contented with that, when he sees a farther 
 examination would lead him into obscure and uncertain specu- 
 lations. In that case his enquiry wou'd be much better 
 employ 'd in examining the effects than the causes of his 
 principle. 
 
 Amongst the effects of this union or association of ideas, 
 there are none more remarkable, than those complex ideas, 
 which are the common subjects of our thoughts and reasoning, 
 and generally arise from some principle of union among our 
 simple ideas. These complex ideas may be divided into 
 Relations, Modes, and Substances. We shall briefly examine 
 each of these in order, and shall subjoin some considerations 
 concerning our general and particular ideas, before we leave the 
 present subject, which may be consider'd as the elements of this 
 philosophy. 
 
 SECTION V. OF RELATIONS 
 
 THE word RELATION is commonly used in two senses con- 
 siderably different from each other. Either for that quality, by 
 which two ideas are connected together in the imagination, 
 and the one naturally introduces the other, after the manner 
 above-explained; or for that particular circumstance, in which, 
 even upon the arbitrary union of two ideas in the fancy, we 
 may think proper to compare them. In common language the 
 former is always the sense, in which we use the word, relation; 
 and 't is only in philosophy, that we extend it to mean any par- 
 ticular subject of comparison, without a connecting principle. 
 Thus distance will be allowed by philosophers to be a true re- 
 lation, because we acquire an idea of it by the comparing of 
 objects: But in a common way we say, that nothing can be
 
 A TREATISE OF HUMAN NATURE 291 
 
 more distant than such or such things from each other, nothing can 
 have less relation; as if distance and relation were incompatible. 
 It may perhaps be esteemed an endless task to enumerate 
 all those qualities, which make objects admit of comparison, 
 and by which the ideas of philosophical relation are produced. 
 But if we diligently consider them, we shall find that without 
 difficulty they may be compriz'd under seven general heads, 
 which may be considered as the source of all philosophical 
 relation. 
 
 1. The first is resemblance: And this is a relation, without 
 which no philosophical relation can exist; since no objects 
 will admit of comparison, but what have some degree of resem- 
 blance. But tho' resemblance be necessary to all philosophical 
 relation, it does not follow, that it always produces a connexion 
 or association of ideas. When a quality becomes very general, 
 and is common to a great many individuals, it leads not the 
 mind directly to any one of them; but by presenting at once too 
 great a choice, does thereby prevent the imagination from fix- 
 ing on any single object. 
 
 2. Identity may be esteem'd a second species of relation. 
 This relation I here consider as apply'd in its strictest sense 
 to constant and unchangeable objects; without examining the 
 nature and foundation of personal identity, which shall find 
 its place afterwards. Of all relations the most universal is that 
 of identity, being common to every being, whose existence has 
 any duration. 
 
 3. After identity the most universal and comprehensive rela- 
 tions are those of Space and Time, which are the sources of an 
 infinite number of comparisons, such as distant, contiguous, 
 above, below, before, after, &c. 
 
 4. All those objects, which admit of quantity, or number, may 
 be compar'd in that particular; which is another very fertile 
 source of relation. 
 
 5. When any two objects possess the same quality in com- 
 mon, the degrees, in which they possess it, form a fifth species 
 of relation. Thus of two objects, which are both heavy, the 
 one may be either of greater, or less weight than with the
 
 292 DAVID HUME 
 
 other. Two colours, that are of the same kind, may yet be of 
 different shades, and in that respect admit of comparison. 
 
 6. The relation of contrariety may at first sight be regarded 
 as an exception to the rule, that no relation of any kind can 
 subsist without some degree of resemblance. But let us consider, 
 that no two ideas are in themselves contrary, except those of 
 existence and non-existence, which are plainly resembling, as 
 implying both of them an idea of the object; tho' the latter 
 excludes the object from all times and places, in which it is sup- 
 posed not to exist. 
 
 7. All other objects, such as fire and water, heat and cold, 
 are only found to be contrary from experience, and from the 
 contrariety of their causes or effects; which relation of cause 
 and effect is a seventh philosophical relation, as well as a 
 natural one. The resemblance implied in this relation, shall be 
 explain'd afterwards. 
 
 It might naturally be expected, that I should join di/erence 
 to the other relations. But that I consider rather as a nega- 
 tion of relation, than as any thing real or positive. Difference 
 is of two kinds as oppos'd either to identity or resemblance. 
 The first is called a difference of number; the other of kind. 
 
 SECTION VI. OF MODES AND SUBSTANCES 
 
 I WOU'D fain ask those philosophers, who found so much 
 of their reasonings on the distinction of substance and acci- 
 dent, and imagine we have clear ideas of each, whether the 
 idea of substance be deriv'd from the impressions of sensation 
 or reflection? If it be convey'd to us by our senses, I ask, 
 which of them ; and after what manner? If it be perceiv'd by 
 the eyes, it must be a colour; if by the ears, a sound; if by the 
 palate, a taste; and so of the other senses. But I believe none 
 will assert, that substance is either a colour, or sound, or a 
 taste. The idea of substance must therefore be deriv'd from an 
 impression or reflection, if it really exist. But the impressions 
 of reflection resolve themselves into our passions and emotions; 
 none of which can possibly represent a substance. We have
 
 A TREATISE OF HUMAN NATURE 293 
 
 therefore no idea of substance, distinct from that of a collection 
 of particular qualities, nor have we any other meaning when we 
 either talk or reason concerning it. 1 
 
 The idea of a substance as well as that of a mode, is nothing 
 but a collection of simple ideas, that are united by the imagina- 
 tion, and have a particular name assigned them, by which we 
 are able to recall, either to ourselves or others, that collection. 
 But the difference betwixt these ideas consists in this, that the 
 particular qualities, which form a substance, are commonly 
 refer'd to an unknown something, in which they are supposed 
 to inhere; or granting this fiction should not take place, are at 
 least supposed to be closely and inseparably connected by the 
 relations of contiguity and causation. The effect of this is, that 
 whatever new simple quality we discover to have the same con- 
 nexion with the rest, we immediately comprehend it among 
 them, even tho' it did not enter into the first conception of the 
 substance. Thus our idea of gold may at first be a yellow 
 colour, weight, malleableness, fusibility; but upon the discov- 
 ery of its dissolubility in aqua regia, we join that to the other 
 qualities, and suppose it to belong to the substance as much as 
 if its idea had from the beginning made a part of the compound 
 one. The principle of union being regarded as the chief part of 
 the complex idea, gives entrance to whatever quality after- 
 wards occurs, and is equally comprehended by it, as are the 
 others, which first presented themselves. 2 
 
 That this cannot take place in modes, is evident from con- 
 sidering their nature. The simple ideas of which modes are 
 formed, either represent qualities, which are not united by 
 contiguity and causation, but are dispers'd in different sub- 
 jects; or if they be all united together, the uniting principle 
 is not regarded as the foundation of the complex idea. The 
 .idea of a dance is an instance of the first kind of modes; that 
 of beauty of the second. The reason is obvious, why such com- 
 plex ideas cannot receive any new idea, without changing the 
 name, which distinguishes the mode. 
 
 1 Cf. Green and Grose's Introduction, 208. 
 
 2 Ibid. 214.
 
 294 DAVID HUME 
 
 PART HI. OF KNOWLEDGE AND PROBABILITY 
 SECTION I. OF KNOWLEDGE 
 
 THERE are l seven different kinds of philosophical relation, 
 viz. resemblance, identity, relations of time and place, propor- 
 tion in quantity or number, degrees in any quality, contrariety, and 
 causation. These relations may be divided into two classes; 
 into such as depend entirely on the ideas, which we compare 
 together, and such as may be chang'd without any change in 
 the ideas. 'T is from the idea of a triangle, that we discover 
 the relation of equality, which its three angles bear to two right 
 ones; and this relation is invariable, as long as our idea remains 
 the same. On the contrary, the relations of contiguity and 
 distance betwixt two objects may be chang'd merely by an 
 alteration of their place, without any change on the objects 
 themselves or on their ideas; and the place depends on a hun- 
 dred different accidents, which cannot be foreseen by the mind. 
 'T is the same case with identity and causation. Two objects, 
 tho' perfectly resembling each other, and even appearing in the 
 safhe place at different times, may be numerically different; 
 And as the power, by which one object produces another, is 
 never discoverable merely from their idea, 't is evident cause 
 and effect are relations, of which we receive information from 
 experience, and not from any abstract reasoning or reflection. 
 There is no single phenomenon, even the most simple, which 
 can be accounted for from the qualities of the objects, as they 
 appear to us; or which we cou'd foresee without the help of our 
 memory and experience. 
 
 It appears, therefore, that of these seven philosophical rela- 
 tions, there remain only four, which depending solely upon 
 ideas, can be the objects of knowledge and certainty. These 
 four are resemblance, contrariety, degrees in quality, and propor- 
 tions in quantity or number. Three of these relations are dis- 
 coverable at first sight, and fall more properly under the pro- 
 vince of intuition than demonstration. When any objects 
 
 1 Part I. sect. 5.
 
 A TREATISE OF HUMAN NATURE 295 
 
 resemble each other, the resemblance will at first strike the eye, 
 or rather the mind; and seldom requires a second examination. 
 The case is the same with contrariety, and with the degrees of 
 any quality. No one can once doubt but existence and non- 
 existence destroy each other, and are perfectly incompatible 
 and contrary. And tho' it be impossible to judge exactly of the 
 degrees of any quality, such as colour, taste, heat, cold, when 
 the difference betwixt them is very small; yet 'tis easy to 
 decide, that any of them is superior or inferior to another, when 
 the difference is considerable. And this decision we always 
 pronounce at first sight, without any enquiry or reasoning. 
 
 We might proceed, after the same manner, in fixing the pro- 
 portions of quantity or number, and might at one view observe 
 a superiority or inferiority betwixt any numbers, or figures; 
 especially where the difference is very great and remarkable. 
 As to equality or any exact proportion, we can only guess at it 
 from a single consideration; except in very short numbers, or 
 very limited portions of extension; which are comprehended in 
 an instant, and where we perceive an impossibility of falling 
 into any considerable error. In all other cases we must settle 
 the proportions with some liberty, or proceed in a more 
 artificial manner. 
 
 I have already observ'd, that geometry, or the art, by which 
 we fix the proportions of figures, tho' it much excels, both in 
 universality and exactness, the loose judgments of the senses 
 and imagination, yet never attains a perfect precision and 
 exactness. Its first principles are still drawn from the general 
 appearance of the objects ; and that appearance can never afford 
 us any security, when we examine the prodigious minuteness of 
 which nature is susceptible. Our ideas seem to give a perfect 
 assurance, that no two right lines can have a common segment; 
 but if we consider these ideas, we shall find, that they always 
 suppose a sensible inclination of the two lines, and that where 
 the angle they form is extremely small, we have no standard 
 of a right line so precise as to assure us of the truth of this 
 proposition. 'T is the same case with most of the primary de- 
 cisions of the mathematics.
 
 296 DAVID HUME 
 
 There remain, therefore, algebra and arithmetic as the only 
 sciences, in which we can carry on a chain of reasoning to any 
 degree of intricacy, and yet preserve a perfect exactness and 
 certainty. We are possest of a precise standard, by which we 
 can judge of the equality and proportion of numbers; and ac- 
 cording as they correspond or not to that standard, we deter- 
 mine their relations, without any possibility of error. When two 
 numbers are so combin'd, as that the one has always an unite 
 answering to every unite of the other, we pronounce them equal ; 
 and 't is for want of such a standard of equality in extension, 
 that geometry can scarce be esteem'd a perfect and infallible 
 science. 
 
 But here it may not be amiss to obviate a difficulty, which 
 may arise from my asserting, that tho' geometry falls short of 
 that perfect precision and certainty, which are peculiar to 
 arithmetic and algebra, yet it excels the imperfect judgments 
 of our senses and imagination. The reason why I impute 
 any defect to geometry, is, because its original and funda- 
 mental principles are deriv'd merely from appearances; and 
 it may perhaps be imagin'd, that this defect must always attend 
 it, and keep it from ever reaching a greater exactness in the 
 comparison of objects or ideas, than what our eye or imagina- 
 tion alone is able to attain. I own that this defect so far at- 
 tends it, as to keep it from ever aspiring to a full certainty: But 
 since these fundamental principles depend on the easiest and 
 least deceitful appearances, they bestow on their consequences 
 a degree of exactness, of which these consequences are singly 
 incapable. 'T is impossible for the eye to determine the angles 
 of a chiliagon to be equal to 1996 right angles, or make any 
 conjecture, that approaches this proportion ; but when it deter- 
 mines, that right lines cannot concur; that we cannot draw 
 more than one right line between two given points; its mistakes 
 can never be of any consequence. And this is the nature and 
 use of geometry, to run us up to such appearances, as, by rea- 
 son of their simplicity, cannot lead us into any considerable 
 error. 
 
 I shall here take occasion to propose a second observation
 
 A TREATISE OF HUMAN NATURE 297 
 
 concerning our demonstrative reasonings, which is suggested 
 by the same subject of the mathematics. 'T is usual with 
 mathematicians, to pretend, that those ideas, which are their 
 objects, are of so refin'd and spiritual a nature, that they fall 
 not under the conception of the fancy, but must be compre- 
 hended by a pure and intellectual view, of which the superior 
 faculties of the soul are alone capable. The same notion runs 
 thro* most parts of philosophy, and is principally made use of 
 to explain our abstract ideas, and to shew how we can form an 
 idea of a triangle, for instance, which shall neither be an isoceles 
 nor scalenum, nor be confin'd to any particular length and pro- 
 portion of sides. 'T is easy to see, why philosophers are so fond 
 of this notion of some spiritual and refin'd perceptions; since by 
 that means they cover many of their absurdities, and may 
 refuse to submit to the decisions of clear ideas, by appealing 
 to such as are obscure and uncertain. But to destroy this arti- 
 fice, we need but reflect on that principle so oft insisted on, that 
 all our ideas are copy'd from our impressions. For from thence 
 we may immediately conclude, that since all impressions are 
 clear and precise, the ideas, which are copy'd from them, must 
 be of the same nature, and can never, but from our fault, con- 
 tain any thing so dark and intricate. An idea is by its very 
 nature weaker and fainter than an impression; but being in 
 every other respect the same, cannot imply any very great 
 mystery. If its weakness render it obscure, 't is our business 
 to remedy that defect, as much as possible, by keeping the 
 idea steady and precise; and till we have done so, 't is in vain 
 to pretend to reasoning and philosophy. 
 
 SECTION II. OF PROBABILITY; AND OF THE IDEA OF CAUSE 
 AND EFFECT 
 
 THIS is all I think necessary to observe concerning those 
 four relations, which are the foundation of science; but as to 
 the other three, which depend not upon the idea, and may be 
 absent or present even while that remains the same, 't will be 
 proper to explain them more particularly. These three rela-
 
 298 DAVID HUME 
 
 tions are identity, the situations in time and place, and causa- 
 tion. 
 
 All kinds of reasoning consist in nothing but a comparison, 
 and a discovery of those relations, either constant or incon- 
 stant, which two or more objects bear to each other. This 
 comparison we may make, either when both the objects are 
 present to the senses, or when neither of them is present, or 
 when only one. When both the objects are present to the 
 senses along with the relation, we call this perception rather 
 than reasoning; nor is there in this case any exercise of the 
 thought, or any action, properly speaking, but a mere passive 
 admission of the impressions thro' the organs of sensation. 1 
 According to this way of thinking, we ought not to receive as 
 reasoning any of the observations we may make concerning 
 identity, and the relations of time and place; since in none of 
 them the mind can go beyond what is immediately present to 
 the senses, either to discover the real existence or the relations 
 of objects. 'T is only causation, which produces such a con- 
 nexion, as to give us assurance from the existence or action of 
 one object, that 't was follow'd or preceded by any other exist- 
 ence or action; nor can the other two relations be ever made 
 use of in reasoning, except so far as they either affect or are 
 affected by it. There is nothing in any objects to perswade us, 
 that they are either always remote or always contiguous; and 
 when from experience and observation we discover, that their 
 relation in this particular is invariable, we always conclude 
 there is some secret cause, which separates or unites them. The 
 same reasoning extends to identity. We readily suppose an 
 object may continue individually the same, tho' several times 
 absent from and present to the senses; and ascribe to it an 
 identity, notwithstanding the interruption of the perception, 
 whenever we conclude, that if we had kept our eye or hand con- 
 stantly upon it, it wou'd have ccnvey'd an invariable and unin- 
 terrupted perception. But this conclusion beyond the impres- 
 sions of our senses can be founded only on the connexion of cause 
 and effect; nor can we otherwise have any security, that the 
 
 1 Cf. Green and Grose's Introduction, 327.
 
 A TREATISE OF HUMAN NATURE 299 
 
 object is not chang'd upon us, however much the new object 
 may resemble that which was formerly present to the senses. 
 Whenever we discover such a perfect resemblance, we consider 
 whether it be common in that species of objects; whether pos- 
 sibly or probably any cause cou'd operate in producing the 
 change and resemblance; and according as we determine con- 
 cerning these causes and effects, we form our judgment concern- 
 ing the identity of the object. 1 
 
 Here then it appears, that of those three relations, which 
 depend not upon the mere ideas, the only one, that can be 
 trac'd beyond our senses, and informs us of existences and 
 objects, which we do not see or feel, is causation. This relation, 
 therefore, we shall endeavour to explain fully before we leave 
 the subject of the understanding. 
 
 To begin regularly, we must consider the idea of causation 
 and see from what origin it is deriv'd. 'T is impossible to reason 
 justly, without understanding perfectly the idea concerning 
 which we reason ; and 't is impossible perfectly to understand 
 any idea, without tracing it up to its origin, and examining that 
 primary impression, from which it arises. The examination of 
 the impression bestows a clearness on the idea; and the exami- 
 nation of the idea bestows a like clearness on all our reasoning. 
 
 Let us therefore cast our eye on any two subjects, which 
 we call cause and effect, and turn them on all sides, in order 
 to find that impression, which produces an idea of such pro- 
 digious consequence. At first sight I perceive, that I must not 
 search for it in any of the particular qualities of the objects; 
 since, which-ever of these qualities I pitch on, I find some 
 object, that is not possest of it, and yet falls under the denom- 
 ination of cause or effect. And indeed there is nothing existent, 
 either externally or internally, which is not to be consider'd 
 either as a cause or an effect; tho' 't is plain there is no one 
 quality, which universally belongs to all beings, and gives them 
 a title to that denomination. 
 
 The idea, then, of causation must be deriv'd from some 
 relation among objects; and that relation we must now ert- 
 
 1 Cf. Green and Grose's Introduction, 313.
 
 300 DAVID HUME 
 
 deavour to discover. I find in the first place, that whatever 
 objects are considered as causes or effects, are contiguous; and 
 that nothing can operate in a time or place, which is ever so 
 little remov'd from those of its existence. Tho' distant objects 
 may sometimes seem productive of each other, they are com- 
 monly found upon examination to be link'd by a chain of 
 causes, which are contiguous among themselves, and to the 
 distant objects; and when in any particular instance we cannot 
 discover this connexion, we still presume it to exist. We may 
 therefore consider the relation of CONTIGUITY as essential to 
 that of causation; at least may suppose it such, according to 
 the general opinion, till we can find a more * proper occasion to 
 clear up this matter, by examining what objects are or are not 
 susceptible of juxtaposition and conjunction. 
 
 The second relation I shall observe as essential to causes 
 and effects, is not so universally acknowledg'd, but is liable to 
 some controversy. 'T is that of PRIORITY of time in the cause 
 before the effect. Some pretend that 't is not absolutely neces- 
 sary a cause shou'd precede its effect; but that any object or 
 action, in the very first moment of its existence, may exert 
 its productive quality, and give rise to another object or action, 
 perfectly co-temporary with itself. But beside that experience 
 in most instances seems to contradict this opinion, we may 
 establish the relation of priority by a kind of inference or rea- 
 soning. 'T is an establish 'd maxim both in natural and moral 
 philosophy, that an object, which exists for any time in its full 
 perfection without producing another, is not its sole cause; but 
 is assisted by some other principle, which pushes it from its 
 state of inactivity, and makes it exert that energy, of which it 
 was secretly possest. Now if any cause may be perfectly co- 
 temporary with its effect, 't is certain, according to this maxim, 
 that they must all of them be so; since any one of them, which 
 retards its operation for a single moment, exerts not itself at 
 that very individual time, in which it might have operated, 
 and therefore is no proper cause. The consequence of this 
 wou'd be no less than the destruction of that succession of 
 
 1 Part IV, sect. 5.
 
 A TREATISE OF HUMAN NATURE 301 
 
 causes, which we observe in the world; and indeed, the utter 
 annihilation of time. For if one cause were co-temporary with 
 its effect, and this effect with its effect, and so on, 't is plain 
 there wou'd be no such thing as succession, and all objects 
 must be co-existent. 
 
 If this argument appear satisfactory, 'tis well. If not, I 
 beg the reader to allow me the same liberty, which I have us'd 
 in the preceding case, of supposing it such. For he shall find, 
 that the affair is of no great importance. 
 
 Having thus disco ver'd or suppos'd the two relations of 
 contiguity and succession to be essential to causes and effects, 
 I find I am stopt short, and can proceed no farther in consider- 
 ing any'single instance of cause and effect. Motion in one body 
 is regarded upon impulse as the cause of motion in another. 
 When we consider these objects with the utmost attention, we 
 find only that the one body approaches the other ; and that the 
 motion of it precedes that of the other, but without any sensible 
 interval. 'T is in vain to rack ourselves with farther thought 
 and reflection upon this subject. We can go no farther in con- 
 sidering this particular instance. 
 
 Shou'd any one leave this instance, and pretend to define a 
 cause, by saying it is something productive of another, 'tis 
 evident he wou'd say nothing. For what does he mean by 
 production? Can he give any definition of it, that will not be 
 the same with that of causation? If he can; I desire it may be 
 produc'd. If he cannot; he here runs in a circle, and gives a 
 synonymous term instead of a definition. 
 
 Shall we then rest contented with these two relations of 
 contiguity and succession, as affording a complete idea of 
 causation? By no means. An object may be contiguous and 
 prior to another, without being consider'd as its cause. There 
 is a NECESSARY CONNEXION to be taken into consideration; 
 and that relation is of much greater importance, than any of 
 the other two above-mention'd. l 
 
 1 Cf. Green and Grose's Introduction, 286.
 
 302 DAVID HUME 
 
 SECTION XIV. OF THE IDEA OF NECESSARY CONNEXION 
 
 It has been establish 'd as a certain principle, that general 
 or abstract ideas are nothing but individual ones taken in a 
 certain light, and that, in reflecting on any object, 't is as 
 impossible to exclude from our thought all particular degrees 
 of quantity and quality as from the real nature of things. If 
 we be possest, therefore, of any idea of power in general, we 
 must also be able to conceive some particular species of it ; and 
 as power cannot subsist alone, but is always regarded as an 
 attribute of some being or existence, we must be able to place 
 this power in some particular being, and conceive tha-t being 
 as endow'd with a real force and energy, by which such a par- 
 ticular effect necessarily results from its operation. We must 
 distinctly and particularly conceive the connexion betwixt the 
 cause and effect, and be able to pronounce, from a simple view 
 of the one, that it must be follow'd or preceded by the other. 
 This is the true manner of conceiving a particular power in a 
 particular body: and a general idea being impossible without an 
 individual; where the latter is impossible, 'tis certain the 
 former can never exist. Now nothing is more evident, than that 
 the human mind cannot form such an idea of two objects, as to 
 conceive any connexion betwixt them, or comprehend distinctly 
 that power or efficacy, by which they are united. Such a con- 
 nexion wou'd amount to a demonstration, and wou'd imply the 
 absolute impossibility for the one object not to follow, or to be 
 conceived not to follow upon the other: Which kind of connex- 
 ion has already been rejected in all cases. If any one is of a 
 contrary opinion, and thinks he has attain 'd a notion of power 
 in any particular object, I desire he may point out to me that 
 object. But till I meet with such-a-one, which I despair of, 1 
 cannot forbear concluding, that since we can never distinctly 
 conceive how any particular power can possibly reside in any 
 particular object, we deceive ourselves in imagining we can 
 form any such general idea. 
 
 Thus upon the whole we may infer, that when we talk of any
 
 A TREATISE OF HUMAN NATURE 303 
 
 being, whether of a superior or inferior nature, as endow'd with 
 a power or force, proportion'd to any effect; when we speak of a 
 necessary connexion betwixt objects, and suppose, that this 
 connexion depends upon an efficacy or energy, with which any 
 of these objects are endow'd; in all these expressions, so apply 'd 
 we have really no distinct meaning, and make use only of com- 
 mon words, without any clear and determinate ideas. But as 
 't is more probable, that these expressions do here lose their 
 true meaning by being wrong apply 'd, than that they never have 
 any meaning; 't will be proper to bestow another consideration 
 on this subject, to see if possibly we can discover the nature and 
 origin of those ideas, we annex to them. 
 
 Suppose two objects to be presented to us, of which the one 
 is the cause and the other the effect; 't is plain, that from the 
 simple consideration of one, or both these objects we never 
 shall perceive the tie, by which they are united, or be able 
 certainly to pronounce, that there is a connexion betwixt them. 
 'T is not, therefore, from any one instance, that we arrive at 
 the idea of cause and effect, of a necessary connexion of power, 
 of force, of energy, and of efficacy. Did we ever see any but 
 particular conjunctions of objects, entirely different from each 
 other, we shou'd never be able to form any such ideas. 
 
 But again; suppose we observe several instances, in which 
 the same objects are always conjoin'd together, we immediately 
 conceive a connexion betwixt them, and begin to draw an in- 
 ference from one to another. This multiplicity of resembling 
 instances, therefore, constitutes the very essence of power or 
 connexion, and is the source, from which the idea of it arises. 
 In order, then, to understand the idea of power, we must con- 
 sider that multiplicity; nor do I ask more to give a solution of 
 that difficulty, which has so long perplex'd us. For thus I rea- 
 son. The repetition of perfectly similar instances can never 
 alone give rise to an original idea, different from what is to be 
 found in any particular instance, as has been observ'd, and as 
 evidently follows from our fundamental principle, that all ideas 
 are copy 1 d from impressions. Since therefore the idea of power 
 is a new original idea, not to be found in any one instance, and
 
 3 o 4 DAVID HUME 
 
 which yet arises from the repetition of several instances, it 
 follows, that the repetition alone has not that effect, but must 
 either discover or produce something new, which is the source 
 of that idea. Did the repetition neither discover nor produce 
 any thing new, our ideas might be multiply'd by it, but wou'd 
 not be enlarg'd above what they are upon the observation of 
 one single instance. Every enlargement, therefore, (such as the 
 idea of power or connexion) which arises from the multiplicity 
 of similar instances, is copy'd from some effects of the multi- 
 plicity, and will be perfectly understood by understanding these 
 effects. Wherever we find any thing new to be discover'd or 
 produc'd by the repetition, there we must place the power, and 
 must never look for it in any other object. 
 
 But 't is evident, in the first place, that the repetition of like 
 objects in like relations of succession and contiguity discovers 
 nothing new in any one of them ; since we can draw no inference 
 from it, nor make it a subject either of our demonstrative ot 
 probable reasonings; as has been already prov'd. Nay sup- 
 pose we cou'd draw an inference, 't wou'd be of no consequence 
 in the present case; since no kind of reasoning can give rise to 
 a new idea, such as this of power is; but wherever we reason, we 
 must antecedently be possest of clear ideas, which may be the 
 objects of our reasoning. The conception always precedes the 
 understanding; and where the one is obscure, the other is un- 
 certain; where the one fails, the other must fail also. 
 
 Secondly, 'T is certain that this repetition of similar objects 
 in similar situations produces nothing new either in these ob- 
 jects, or in any external body. For' t will readily be allow'd, that 
 the several instances we have of the conjunction of resembling 
 causes and effects are in themselves entirely independent, and 
 that the communication of motion, which I see result at present 
 from the shock of two billiard-balls, is totally distinct from that 
 which I saw result from such an impulse a twelve-month ago. 
 These impulses have no influence on each other. . They are 
 entirely divided by time and place; and the one might have 
 existed and communicated motion, tho' the other never had 
 been in being.
 
 A TREATISE OF HUMAN NATURE 305 
 
 There is, then, nothing new either discovered or produc'd in 
 any objects by their constant conjunction, and by the uninter- 
 rupted resemblance of their relations of succession and con- 
 tiguity. But 't is from this resemblance, that the ideas of 
 necessity, of power, and of efficacy, are deriv'd. These ideas, 
 therefore, represent not any thing, that does or can belong to 
 the objects, which are constantly conjoin'd. This is an argu- 
 ment, which, in every view we can examine it, will be found 
 perfectly unanswerable. Similar instances are still the first 
 source of our idea of power or necessity; at the same time that 
 they have no influence by their similarity either on each other, 
 or on any external object. We must therefore, turn ourselves 
 to some other quarter to seek the origin of that idea. 
 
 Tho' the several resembling instances, which give rise to 
 the idea of power, have no influence on each other, and can 
 never produce any new quality in the object, which can be the 
 model of that idea, yet the observation of this resemblance 
 produces a new impression in the mind, which is its real model. 
 For after we have observ'd the resemblance in a sufficient 
 number of instances, we immediately feel a determination of 
 the mind to pass from one object to its usual attendant, and to 
 conceive it in a stronger light upon account of that relation. 
 This determination is the only effect of the resemblance; and 
 therefore must be the same with power or efficacy, whose idea 
 is deriv'd from the resemblance. The several instances of re- 
 sembling conjunctions leads us into the notion of power and 
 necessity. These instances are in themselves totally distinct 
 from each other, and have no union but in the mind, which ob- 
 serves them, and collects their ideas. Necessity, then, is the 
 effect of this observation, and is nothing but an internal impres- 
 sion of the mind, or a determination to carry our thoughts from 
 one object to another. Without considering it in this view, we 
 can never arrive at the most distant notion of it, or be able to 
 attribute it either to external or internal objects, to spirit or 
 body, to causes or effects. 
 
 The necessary connexion betwixt causes and effects is the 
 foundation of our inference from one to the other. The founda-
 
 3 o6 DAVID HUME 
 
 tion of our inference is the transition arising from the accus- 
 tom 'd union. These are, therefore, the same. 
 
 The idea of necessity arises from some impression. There 
 is no impression convey'd by our senses, which can give rise 
 to that idea. It must, therefore, be deriv'd from some internal 
 impression, or impression of reflection. There is no internal 
 impression, which has any relation to the present business, 
 but that propensity, which custom produces, to pass from an 
 object to the idea of its usual attendant. This therefore is the 
 essence of necessity. Upon the whole, necessity is something, 
 that exists in the mind, not in objects; nor is it possible for us 
 ever to form the most distant idea of it, consider'd as a quality 
 in bodies. Either we have no idea of necessity, or necessity is 
 nothing but that determination of the thought to pass from 
 causes to effects and from effects to causes, according to their 
 experienc'd union. 
 
 Thus as the necessity, which makes two times two equal to 
 four, or three angles of a triangle equal to two right ones, lies 
 only in the act of the understanding, by which we consider and 
 compare these ideas; in like manner the necessity or power, 
 which unites causes and effects, lies in the determination of the 
 mind to pass from the one to the other. The efficacy or energy 
 of causes is neither plac'd in the causes themselves, nor in 
 the deity, nor in the concurrence of these two principles; but 
 belongs entirely to the soul, which considers the union of two 
 or more objects in all past instances. 'T is here that the real 
 power of causes is plac'd, along with their connexion and 
 necessity. 
 
 I am sensible, that of all the paradoxes, which I have had, 
 or shall hereafter have occasion to advance in the course of this 
 treatise, the present one is the most violent, and that 'tis 
 merely by dint of solid proof and reasoning I can ever hope it 
 will have admission, and overcome the inveterate prejudices 
 of mankind. Before we are reconcil'd to this doctrine, how 
 often must we repeat to ourselves, that the simple view of any 
 two objects or actions, however related, can never give us any 
 idea of power, or of a connexion betwixt them: that this idea
 
 A TREATISE OF HUMAN NATURE 307 
 
 arises from the repetition of their union: that the repetition 
 neither discovers nor causes any thing in the objects, but has 
 an influence only on the mind, by that customary transition it 
 produces: that this customary transition is, therefore, the same 
 with the power and necessity; which are consequently qualities 
 of perceptions, not of objects, and are internally felt by the 
 soul, and not perceiv'd externally in bodies? There is com- 
 monly an astonishment attending every thing extraordinary; 
 and this astonishment changes immediately into the highest 
 degree of esteem or contempt, according as we approve or dis- 
 approve of the subject. I am much afraid, that tho' the fore- 
 going reasoning appears to me the shortest and most decisive 
 imaginable; yet with the generality of readers the biass of the 
 mind will prevail, and give them a prejudice against the present 
 doctrine. 
 
 This contrary biass is easily accounted for. 'T is a common 
 observation, that the mind has a great propensity to spread 
 itself on external objects, and to conjoin with them any internal 
 impressions, which they occasion, and which always make their 
 appearance at the same time that these objects discover them- 
 selves to the senses. Thus as certain sounds and smells are 
 always found to attend certain visible objects, we naturally 
 imagine a conjunction, even in place, betwixt the objects and 
 qualities, tho' the qualities be of such a nature as to admit of 
 no such conjunction, and really exist no where. But of this 
 more fully l hereafter. Mean while 't is sufficient to observe, 
 that the same propensity is the reason, why we suppose neces- 
 sity and power to lie in the objects we consider, not in our mind, 
 that considers them ; notwithstanding it is not possible for us 
 to form the most distant idea of that quality, when it is not 
 taken for the determination of the mind, to pass from the idea 
 of an object to that of its usual attendant. 
 
 But tho' this be the only reasonable account we can give of 
 necessity, the contrary notion is so riveted in the mind from the 
 principles above-mention'd, that I doubt not but my senti- 
 ments will be treated by many as extravagant and ridiculous. 
 
 1 Part IV, sect. 5.
 
 308 DAVID HUME 
 
 What! the efficacy of causes lie in the determination of the 
 mind! As if causes did not operate entirely independent of the 
 mind, and wou'd not continue their operation, even tho' there 
 was no mind existent to contemplate them, or reason concern- 
 ing them. Thought may well depend on causes for its opera- 
 tion, but not causes on thought. This is to reverse the order of 
 nature, and make that secondary, which is really primary. To 
 every operation there is a power proportion 'd; and this power 
 must be plac'd on the body, that operates. If we remove the 
 power from one cause, we must ascribe it to another: But to 
 remove it from all causes, and bestow it on a being, that is no 
 ways related to the cause or effect, but by perceiving them, is a 
 gross absurdity, and contrary to the most certain principles of 
 human reason. 
 
 I can only reply to all these arguments, that the case is here 
 much the same, as if a blind man shou'd pretend to find a great 
 many absurdities in the supposition, that the colour of scarlet 
 is not the same with the sound of a trumpet, nor light the same 
 with solidity. If we have really no idea of a power or efficacy 
 in any object, or of any real connexion betwixt causes and 
 effects, 't will be to little purpose to prove, that an efficacy is ne- 
 cessary in all operations. We do not understand our own mean- 
 ing in talking so, but ignorantly confound ideas, which are en- 
 tirely distinct from each other. I am, indeed, ready to allow, 
 that there maybe several qualities both in material and imma- 
 terial objects, with which we are utterly unacquainted; and if 
 we please to call these power or efficacy, 't will be of little conse- 
 quence to the world. But when, instead of meaning these un- 
 known qualities, we make the terms of power and efficacy sig- 
 nify something, of which we have a clear idea, and which is 
 incompatible with those objects, to which we apply it, obscur- 
 ity and error begin then to take place, and we are led astray by 
 a false philosophy. This is the case, when we transfer the de- 
 termination of the thought to external objects, and suppose any 
 real intelligible connexion betwixt them; that being a quality, 
 which can only belong to the mind that considers them. 
 
 As to what may be said, that the operations of nature are
 
 A TREATISE OF HUMAN NATURE 309 
 
 independent of our thought and reasoning, I allow it; and ac- 
 cordingly have observ'd, that objects bear to each other the 
 relations of contiguity and succession ; that like objects may be 
 observ'd in several instances to have like relations; and that all 
 this is independent of, and antecedent to the operations of the 
 understanding. But if we go any farther, and ascribe a power 
 or necessary connexion to these objects; this is what we can 
 never observe in them, but must draw the idea of it from what 
 we feel internally in contemplating them. And this I carry so 
 far, that I am ready to convert my present reasoning into an 
 instance of it, by a subtility, which it will not be difficult to 
 comprehend. 
 
 When any object is presented to us, it immediately conveys 
 to the mind a lively idea of that object, which is usually found 
 to attend it; and this determination of the mind forms the 
 necessary connexion of these objects. But when we change the 
 point of view, from the objects to the perceptions; in that case 
 the impression is to be considered as the cause, and the lively 
 idea as the effect; and their necessary connexion is that new 
 determination, which we feel to pass from the idea of the one to 
 that of the other. The uniting principle among our internal 
 perceptions is as unintelligible as that among external objects, 
 and is not known to us any other way than by experience. Now 
 the nature and effects of experience have been already suffi- 
 ciently examin'd and explain'd. It never gives us any insight 
 into the internal structure or operating principle of objects, but 
 only accustoms the mind to pass from one to another. 
 
 'T is now time to collect all the different parts of this reason- 
 ing, and by joining them together form an exact definition of 
 the relation of cause and effect, which makes the subject of the 
 present enquiry. This order wou'd not have been excusable, of 
 first examining our inference from the relation before we had 
 explain'd the relation itself, had it been possible to proceed in a 
 different method. But as the nature of the relation depends so 
 much on that of the inference, we have been oblig'd to advance 
 in this seemingly preposterous manner, and make use of terms 
 before we were able exactly to define them, or fix their meaning.
 
 3 io DAVID HUME 
 
 We shall now correct this fault by giving a precise definition of 
 cause and effect. 
 
 There may two definitions be given of this relation, which 
 are only different, by their presenting a different view of the 
 same object, and making us consider it either as a philosophical 
 or as a natural relation; either as a comparison of two ideas, 
 or as an association betwixt them. We may define a CAUSE to 
 be 'An object precedent and contiguous to another, and where 
 all the objects resembling the former are plac'd in like relations 
 of precedency and contiguity to those objects, that resemble 
 the latter.' If this definition be esteem'd defective, because 
 drawn from objects foreign to the cause, we may substitute this 
 other definition in its place, viz. 'A CAUSE is an object precedent 
 and contiguous to another, and so united with it, that the idea 
 of the one determines the mind to form the idea of the other, 
 and the impression of the one to form a more lively idea of the 
 other.' Shou'd this definition also be rejected for the same 
 reason, I know no other remedy, than that the persons, who 
 express this delicacy, should substitute a juster definition in its 
 place. But for my part I must own my incapacity for such an 
 undertaking. When I examine with the utmost accuracy those 
 objects, which are commonly denominated causes and effects, 
 I find, in considering a single instance, that the one object 
 is precedent and contiguous to the other; and in inlarging my 
 \ iew to consider several instances, I find only, that like objects 
 are constantly plac'd in like relations of succession and contig- 
 uity. Again, when I consider the influence of this constant 
 conjunction, I perceive, that such a relation can never be an 
 object of reasoning, and can never operate upon the mind, 
 but by means of custom, which determines the imagination to 
 make a transition from the idea of one object to that of its 
 usual attendant, and from the impression of one to a more 
 lively idea of the other. However extraordinary these senti- 
 ments may appear, I think it fruitless to trouble myself with 
 any farther enquiry or reasoning upon the subject, but shall 
 repose myself on them as on establish'd maxims. 
 
 'T will only be proper, before we leave this subject, to draw
 
 A TREATISE OF HUMAN NATURE 311 
 
 some corrollaries from it, by which we may remove several 
 prejudices and popular errors, that have very much prevail'd 
 in philosophy. First, We may learn from the foregoing doc- 
 trine, that all causes are of the same kind, and that in particular 
 there is no foundation for that distinction, which we sometimes 
 make betwixt efficient causes, and causes sine qua non; or be- 
 twixt efficient causes, and formal, and material, and exem- 
 plary, and final causes. For as our idea of efficiency is deriv'd 
 from the constant conjunction of two objects, wherever this is 
 observ'd, the cause is efficient and where it is not, there can 
 never be a cause of any kind. For the same reason we must 
 reject the distinction betwixt cause and occasion, when sup- 
 pos'd to signify any thing essentially different from each other. 
 If constant conjunction be imply'd in what we call occasion, 
 't is a real cause. If not, 't is no relation at all, and cannot give 
 rise to any argument or reasoning. 
 
 Secondly, The same course of reasoning will make us con- 
 clude, that there is but one kind of necessity, as there is but one 
 kind of cause, and that the common distinction betwixt moral 
 and physical necessity is without any foundation in nature. 
 This clearly appears from the precedent explication of neces- 
 sity. 'T is the constant conjunction of objects, along with the 
 determination of the mind, which constitutes a physical neces- 
 sity : And the removal of these is the same thing with chance. As 
 objects must either be conjoin'd or not, and as the mind must 
 either be determin'd or not to pass from one object to another, 
 't is impossible to admit of any medium betwixt chance and an 
 absolute necessity. In weakening this conjunction and deter- 
 mination you do not change the nature of the necessity; since 
 even in the operation of bodies, these have different degrees of 
 constancy and force, without producing a different species of 
 that relation. 
 
 The distinction, which we often make betwixt power and 
 the exercise of it, is equally without foundation. 
 
 Thirdly, We may now be able fully to overcome all that 
 repugnance, which 't is so natural for us to entertain against 
 the foregoing reasoning, by which we endeavour'd to prove,
 
 312 DAVID HUME 
 
 that the necessity of a cause to every beginning of existence 
 is not founded on any arguments either demonstrative or intui- 
 tive. Such an opinion will not appear strange after the fore- 
 going definitions. If we define a cause to be an object precedent 
 and contiguous to another, and where all the objects resembling the 
 former are plac'd in a like relation of priority and contiguity to 
 those objects, that resemble the latter; we may easily conceive, that 
 there is no absolute nor metaphysical necessity, that every 
 beginning of existence shou'd be attended v/ith such an object. 
 If we define a cause to be, An object precedent and contiguous to 
 another, and so united with it in the imagination, that the idea of 
 the one determines the mind to form the idea of the other, and the 
 impression of the one to form a more lively idea of the other; we 
 shall make still less difficulty of assenting to this opinion. Such 
 an influence on the mind is in itself perfectly extraordinary 
 and incomprehensible; nor can we be certain of its reality, but 
 from experience and observation. 
 
 I shall add as a fourth corrollary, that we can never have 
 reason to believe that any object exists, of which we cannot 
 form an idea. For as all our reasonings concerning existence 
 are deriv'd from causation, and as all our reasonings concerning 
 causation are deriv'd from the experienc'd conjunction of 
 objects, not from any reasoning or reflection, the same experi- 
 ence must give us a notion of these objects, and must remove 
 all mystery from our conclusions. This is so evident, that 
 'twou'd scarce have merited our attention, were it not to 
 obviate certain objections of this kind, which might arise 
 against the following reasonings concerning matter and sub- 
 stance. I need not observe, that a full knowledge of the object 
 is not requisite, but only of those qualities of it, which we 
 believe to exist.
 
 DAVID HARTLEY 
 
 (1705-1757) 
 
 OBSERVATIONS ON MAN, HIS FRAME, HIS 
 DUTY, AND HIS EXPECTATIONS* 
 
 PART I. INTRODUCTION f 
 
 MAN consists of two parts, body and mind. 
 
 The first is subjected to our senses and inquiries, in the same 
 manner as the other parts of the external material world. 
 
 The last is that substance, agent, principle, &c. to which we 
 refer the sensations, ideas, pleasures, pains, and voluntary 
 motions. 
 
 Sensations are those internal feelings of the mind, which arise 
 from the impressions made by external objects upon the several 
 parts of our bodies. 
 
 All our other internal feelings may be called ideas. Some 
 of these appear to spring up in the mind of themselves, some 
 are suggested by words, others arise in other ways. Many 
 writers comprehend sensations under ideas; but I every where 
 use these words in the senses here ascribed to them. 
 
 * London, 1749; id ed. (with Life), 1791; 6th rev. ed. 1834. 
 
 t Hartley describes the origin of the Observations on Man, in its Preface, as 
 follows: "About eighteen years ago [1731] I was informed, that the Rev. Mr. 
 Gay, then living, asserted the possibility of deducing all our intellectual pleasures 
 and pains from association. This put me upon considering the power of associa- 
 tion. Mr. Gay published his sentiments on this matter, about the same time, in 
 a Dissertation on the Fundamental Principle of Virtue, prefixed to Mr. Arch- 
 deacon Law's translation of Archbishop King's Origin of Evil." 
 
 The internal evidence, moreover, tends to prove that the anonymous tract 
 entitled, An Enquiry into the Origin of the Human Appetite and Affections, 
 shewing how each arises from Association, Lincoln 1747, which is the fourth of 
 Rev. Samuel Parr's Metaphysical Tracts, Lond. 1837, was also written by the 
 'modest' Gay, whose priority as regards the doctrine of association is thereby 
 more firmly secured.
 
 DAVID HARTLEY 
 
 / 
 
 The ideas which resemble sensations, are called ideas of sen- 
 sation: all the rest may therefore be called intellectual ideas. 
 
 It will appear in the course of these observations, that the 
 ideas of sensation are the elements of which all the rest are 
 compounded. Hence ideas of sensation may be termed simple, 
 intellectual ones complex. 
 
 The pleasures and pains are comprehended under the sensa- 
 tions and ideas, as these are explained above. For all our pleas- 
 ures and pains are internal feelings, and conversely, all our 
 internal feelings seem to be attended with some degree either of 
 pleasure or pain. However, I shall, for the most part, give the 
 names of pleasure and pain only to such degrees as are consider- 
 able; referring all low evanescent ones to the head of mere 
 sensations and ideas. 
 
 The pleasures and pains may be ranged under seven general 
 classes; viz. 
 
 1. Sensation; 
 
 2. Imagination; 
 
 3. Ambition; 
 
 4. Self-interest; 
 
 5. Sympathy; 
 
 6. Theopathy; and, 
 
 7. The Moral Sense; according as they arise from, 
 
 1. The impressions made on the external senses; 
 
 2. Natural or artificial beauty or deformity; 
 
 3. The opinions of others concerning us; 
 
 4. Our possession or want of the means of happiness, and 
 security from, or subjection to, the hazards of misery; 
 
 5. The pleasures and pains of our fellow-creatures; 
 
 6. The affections excited in us by the contemplation of the 
 Deity; or 
 
 7. Moral beauty and deformity. 
 
 The human mind may also be considered as endued with the 
 faculties of memory, imagination, or fancy, understanding, affec- 
 tion, and will.
 
 OBSERVATIONS ON MAN 315 
 
 CHAPTER I. THE DOCTRINES OF VIBRATIONS AND 
 ASSOCIATION IN GENERAL 
 
 MY chief design in the following chapter is briefly to explain, 
 establish, and apply the doctrines of vibrations and association. 
 The first of these doctrines is taken from the hints concerning 
 the performance of sensation and motion, which Sir Isaac New- 
 ton has given at the end of his Principia, 1 and in the Questions 
 annexed to his Optics 2 ; the last, from what Mr. Locke, 3 and other 
 ingenious persons since his time, have delivered concerning the 
 influence of association over our opinions and affections, and its 
 use in explaining those things in an accurate and precise way, 
 which are commonly referred to the power of habit and custom, 
 is a general and indeterminate one. 
 
 The doctrine of vibrations may appear at first sight to have 
 no connexion with that of association; however, if these doc- 
 trines be found in fact to contain the laws of the bodily and 
 mental powers respectively, they must be related to each other, 
 since the body and mind are. One may expect, that vibrations 
 should infer association as their effect, and association point to 
 vibrations as its cause. I will endeavour, in the present chapter, 
 to trace out this mutual relation. 
 
 The proper method of philosophizing seems to be, to discover 
 and establish the general laws of action, affecting the subject 
 under consideration, from certain select, well-defined, and well- 
 attested phenomena, and then to explain and predict the other 
 phaenomena by these laws. This is the method of analysis and 
 synthesis recommended and followed by Sir Isaac Newton. 
 
 I shall not be able to execute, with any accuracy, what the 
 reader might expect of this kind, in respect of the doctrines of 
 vibrations and association, and their general laws, on account 
 of the great intricacy, extensiveness, and novelty of the sub- 
 ject. However, I will attempt a sketch in the best manner I 
 can, for the service of future inquirers. 
 
 1 Newton's Philosophiae naluralis principia mathematicoa, Lond. 1687. 
 
 2 Newton's Treatise of Optics, Lond. 1784. 
 
 * Locke's An Essay Concerning Human Understanding, Lond. 1690.
 
 3i6 DAVID HARTLEY 
 
 SECTION I. THE DOCTRINE OF VIBRATIONS, AND ITS USE FOR 
 
 EXPLAINING THE SENSATIONS 
 
 PROP. I. The white medullary Substance of the Brain, spinal 
 Marrow, and the Nerves proceeding from them, is the imme- 
 diate Instrument of Sensation and Motion. 
 
 UNDER the word brain, in these observations, I comprehend 
 all that lies within the cavity of the skull, i.e. the cerebrum, or 
 brain properly so called, the cerebellum, and the medulla 
 oblongata. 
 
 This proposition seems to be sufficiently proved in the writ- 
 ings of physicians and anatomists; from the structure and func- 
 tions of the several organs of the human body; from experi- 
 ments on living animals; from the symptoms of diseases, and 
 from dissections of morbid bodies. Sensibility, and the power 
 of motion, seem to be conveyed to all the parts, in their natural 
 state, from the brain and spinal marrow, along the nerves. 
 These arise from the medullary, not the cortical part, every 
 where, and are themselves of a white medullary substance. 
 When the nerves of any part are cut, tied, or compressed in any 
 considerable degree, the functions of that part are either 
 entirely destroyed, or much impaired. When the spinal mar- 
 row is compressed by a dislocation of the vertebra of the back, 
 all the parts, whose nerves arise below the place of dislocation, 
 become paralytic. When any considerable injury is done to the 
 medullary substance of the brain, sensation, voluntary motion, 
 memory, and intellect, are either entirely lost, or much im- 
 paired; and if the injury be very great, this extends immedi- 
 ately to the vital motions also, viz. to those of the heart, and 
 organs of respiration, so as to occasion death. But this does not 
 hold equally in respect of the cortical substance of the brain; 
 perhaps not at all, unless as far as injuries done to it extend 
 themselves to the medullary substance. In dissections after 
 apoplexies, palsies, epilepsies, and other distempers affecting 
 the sensations and motions, it is usual to find some great dis- 
 order in the brain, from preternatural tumours, from blood, 
 matter, or serum, lying upon the brain, or in its ventricles, &c.
 
 OBSERVATIONS ON MAN 317 
 
 This may suffice as general evidence for the present. The par- 
 ticular reasons of some of these phaenomena, with more definite 
 evidences, will offer themselves in the course of these observa- 
 tions. 
 
 PROP. II. The white medullary Substance of the Brain is also 
 the immediate Instrument, by which Ideas are presented to the 
 Mind: or, in other words, whatever Changes are made in this 
 Substance, corresponding Changes are made in our Ideas; and 
 vice versa. 
 
 THE evidence for this proposition is also to be taken from the 
 writings of physicians and anatomists; but especially from 
 those parts of these writings which treat of the faculties of 
 memory, attention, imagination, &c. and of mental disorders. 
 It is sufficiently manifest from hence, that the perfection of our 
 mental faculties depends upon the perfection of this substance; 
 that all injuries done to it affect the trains of ideas proportion- 
 ably ; and that these cannot be restored to their natural course 
 till such injuries be repaired. Poisons, spirituous liquors, opi- 
 ates, fevers, blows upon the head, &c. all plainly affect the 
 mind, by first disordering the medullary substance. And evac- 
 uations, rest, medicines, time., &c. as plainly restore the mind 
 to its former state, by reversing the foregoing steps. But there 
 will be more and more definite evidence offered in the course of 
 these observations. 
 
 PROP. III. The Sensations remain in the Mind for a short time 
 
 after the sensible Objects are removed. 
 
 THIS is very evident in the sensations impressed on the eye. 
 Thus, to use Sir Isaac Newton's words, "If a burning coal be 
 nimbly moved round in a circle, with gyrations continually re- 
 peated, the whole circle will appear like fire; the reason of 
 which is, that the sensation of the coal, in the several places of 
 that circle, remains impressed on the sensorium until the coal 
 return again to the same place. And so in a quick consecution 
 of the colours," (viz. red, yellow, green, blue, and purple, men- 
 tioned in the experiment, whence this passage is taken,) "the
 
 3 i8 DAVID HARTLEY 
 
 impression of every colour remains on the sensorium until a 
 revolution of all the colours be completed, and that first colour 
 return again. The impressions therefore of all the successive 
 colours are at once in the sensorium and beget a sensation 
 of white." Opt. b. I. p. 2. Experiment 10. 
 
 Thus also, when a person has had a candle, a window, or any 
 other lucid and well-defined object, before his eyes for a con- 
 siderable time, he may perceive a very clear and precise image 
 thereof to be left in the sensorium, fancy, or mind (for these I 
 consider as equivalent expressions in our entrance upon these 
 disquisitions,) for some time after he has closed his eyes. At 
 least this will happen frequently to persons who are attentive 
 to these things in a gentle way; for, as this appearance escapes 
 the notice of those who are entirely inattentive, so too earnest 
 a desire and attention prevents it, by introducing another state 
 of mind or fancy. 
 
 To these may be referred the appearance mentioned by Sir 
 Isaac Newton, Opt. Qu. 16. viz. "When. a man in the dark 
 presses either corner of his eye with his finger, and turns his eye 
 away from his finger, he will see a circle of colours like those in 
 the feather of a peacock's tail. And this appearance continues 
 about a second of time after the eye and finger have remained 
 quiet." The sensation continues therefore in the mind about a 
 second of time after its cause ceases to act. 
 
 The same continuance of the sensations is also evident in the 
 ear. For the sounds which we hear are reflected by the neigh- 
 bouring bodies, and therefore consist of a variety of sounds, 
 succeeding each other at different distances of time, according 
 to the distances of the several reflecting bodies; which yet 
 causes no confusion or apparent complexity of sound, unless the 
 distance of the reflecting bodies be very considerable, as in spa- 
 cious buildings. Much less are we able to distinguish the suc- 
 cessive pulses of the air, even in the gravest sounds. 
 
 As to the senses of taste and smell, there seems to be no clear 
 direct evidence for the continuance of their sensations after the 
 proper objects are removed. But analogy would incline one to 
 believe, that they must resemble the senses of sight and hearing
 
 OBSERVATIONS ON MAN 319 
 
 in this particular, though the continuance cannot be perceived 
 distinctly, on account of the shortness of it, or other circum- 
 stances. For the sensations must be supposed to bear such an 
 analogy to each other, and so to depend in common upon the 
 brain, that all evidences for the continuance of sensations in 
 any one sense, will extend themselves to the rest. Thus all the 
 senses may be considered as so many kinds of feeling; the taste 
 is nearly allied to the feeling, the smell to the taste, and the 
 sight and hearing to each other. All which analogies will offer 
 themselves to view when we come to examine each of these 
 senses in particular. 
 
 In the sense of feeling, the continuance of heat, after the 
 heating body is removed, and that of the smart of a wound, 
 after the instant of infliction, seem to be of the same kind with 
 the appearances taken notice of in the eye and ear. 
 
 But the greatest part of the sensations of this sense resemble 
 those of taste and smell, and vanish to appearance as soon as 
 the objects are removed. 
 
 PROP. IV. External Objects impressed upon the Senses occa- 
 sion, first in the Nerves on which they are impressed, and then in 
 the Brain, Vibrations of the small, and as one may say, infini- 
 tesimal, medullary Particles. 
 
 THESE vibrations are motions backwards and forwards of the 
 small particles; of the same kind with the oscillations of pen- 
 dulums, and the tremblings of the particles of sounding bodies. 
 They must be conceived to be exceedingly short and small, so 
 as not to have the least efficacy to disturb or move the whole 
 bodies of the nerves or brain. For that the nerves themselves 
 should vibrate like musical strings, is highly absurd; nor was it 
 ever asserted by Sir Isaac Newton, or any of those who have 
 embraced his notion of the performance of sensation and mo- 
 tion, by means of vibrations. 
 
 In like manner we are to suppose the particles which vibrate, 
 to be of the inferior orders, and not those biggest particles, on 
 which the operations in chemistry, and the colours of natural 
 bodies, depend, according to the opinion of Sir Isaac Newton.
 
 320 DAVID HARTLEY 
 
 Hence, in the proposition, I term the medullary particles, which 
 vibrate, infinitesimal. 
 
 Now that external objects impress vibratory motions upon 
 the medullary substance of the nerves and brain (which is the 
 immediate instrument of sensation, according to the first pro- 
 position) appears from the continuance of the sensations men- 
 tioned in the third; since no motion, besides a vibratory one, 
 can reside in any part for the least moment of time. External 
 objects, being corporeal, can act upon the nerves and brain, 
 which are also corporeal, by nothing but impressing motion on 
 them. A vibrating motion may continue for a short time in the 
 small medullary particles of the nerves and brain, without dis- 
 turbing them, and after a short time would cease; and so would 
 correspond to the above-mentioned short continuance of the 
 sensations; and there seems to be no other species of motion 
 that can correspond thereto. 
 
 COR. As this proposition is deduced from the foregoing, so 
 if it could be established upon independent principles, (of 
 which I shall treat under the next,) the foregoing might be de- 
 duced from it. And on this supposition there would be an argu- 
 ment for the continuance of the sensations, after the removal 
 of their objects; which would extend to the senses of feeling, 
 taste, and smell, in the same manner as to those of sight and 
 hearing. 
 
 SECTION II. OF IDEAS, THEIR GENERATION AND ASSOCIA- 
 TIONS; AND OF THE AGREEMENT OF THE DOCTRINE OF Vl- 
 BRATIONS WITH THE PHENOMENA OF IDEAS. 
 
 PROP. VIII. Sensations, by being often repeated, leave certain 
 Vestiges, Types, or Images, of themselves, which may be called, 
 Simple Ideas of Sensation. 
 
 I TOOK notice in the Introduction, that those ideas which 
 resemble sensations were called ideas of sensation ; and also that 
 they might be called simple ideas, in respect of the intellectual 
 ones which are formed from them, and of whose very essence it 
 is to be complex. But the ideas of sensation are not entirely
 
 OBSERVATIONS ON MAN 321 
 
 simple, since they must consist of parts both co-existeat and 
 successive, as the generating sensations themselves do. 
 
 Now, that the simple ideas of sensation are thus generated, 
 agreeably to the proposition, appears, because the most vivid 
 of these ideas are those where the corresponding sensations 
 are most vigorously impressed, or most frequently renewed; 
 whereas if the sensation be faint, or uncommon, the generated 
 idea is also faint in proportion, and, in extreme cases, evanes- 
 cent and imperceptible. The exact observance of the order of 
 place in visible ideas, and of the order of time in audible ones, 
 may likewise serve to shew, that these ideas are copies and off- 
 springs of the impressions made on the eye and ear, in which the 
 same orders were observed respectively. And though it hap- 
 pens, that trains of visible and audible ideas are presented in 
 sallies of the fancy, and in dreams, in which the order of time 
 and place is different from that of any former impressions, yet 
 the small component parts of these trains are copies of former 
 impressions; and reasons may be given for the varieties of their 
 compositions. 
 
 It is also to be observed, that this proposition bears a great 
 resemblance to the third; and that, by this resemblance, they 
 somewhat confirm and illustrate one another. According to the 
 . third proposition, sensations remain for a short time after the 
 impression is removed; and these remaining sensations grow 
 feebler and feebler, till they vanish. They are therefore, in 
 some part of their declension, of about the same strength with 
 ideas, and in their first state, are intermediate between sensa- 
 tions and ideas. And it seems reasonable to expect, that, if a 
 single sensation can leave a perceptible effect, trace, or vestige, 
 for a short time, a sufficient repetition of a sensation may leave 
 a perceptible effect of the same kind, but of a more permanent 
 nature, i.e. an idea, which shall recur occasionally, at long 
 distances of time, from the impression of the corresponding 
 sensation, and vice versa. As to the occasions and causes, which 
 make ideas recur, they will be considered in the next proposi- 
 tion but one. 
 
 The method of reasoning used in the last paragraph is farther
 
 322 DAVID HARTLEY 
 
 confirmed by the following circumstance; viz. that both the 
 diminutive declining sensations, which remain for a short space 
 after the impressions of the objects cease, and the ideas, which 
 are the copies of such impressions, are far more distinct and vivid 
 in respect of visible and audible impressions, than of any others. 
 To which it may be added, that, after travelling, hearing music, 
 &c. trains of vivid ideas are very apt to recur, which correspond 
 very exacjtly to the late impressions, and which are of an inter- 
 mediate nature between the remaining sensations of the third 
 proposition, in their greatest vigour, and the ideas mentioned 
 in this. 
 
 The sensations of feeling, taste and smell, can scarce be said 
 to leave ideas, unless very indistinct and obscure ones. How- 
 ever, an analogy leads one to suppose that these sensations may 
 leave traces of the same kind, though not in the same degree, 
 as those of sight and hearing; so the readiness with which we 
 reconnoitre sensations of feeling, taste, and smell, that have 
 been often impressed, is an evidence that they do so; and these 
 generated traces or dispositions of mind may be called the 
 ideas of feeling, taste, and smell. In sleep, when all our ideas 
 are magnified, those of feeling, taste, and smell, are often suffi- 
 ciently vivid and distinct; and the same thing happens in some 
 few cases of vigilance. 
 
 PROP. IX. Sensory Vibrations, by being often repeated, beget, 
 in the medullary Substance of the Brain, a Disposition to 
 diminutive Vibrations, which may also be called Vibratiuncles, 
 and Miniatures, corresponding to themselves respectively. 
 THIS correspondence of the diminutive vibrations to the 
 original sensory ones, consists in this, that they agree in kind, 
 place, and line of direction; and differ only in being more feeble, 
 i.e. in degree. 
 
 This proposition follows from the foregoing. For since sensa- 
 tions, by being often repeated, beget ideas, it cannot but be 
 that those vibrations, which accompany sensations, should be- 
 get something which may accompany ideas in like manner; and 
 this can be nothing but feebler vibrations, agreeing with the
 
 OBSERVATIONS ON MAN 323 
 
 sensory generating vibrations in kind, place, and line of 
 direction. 
 
 Or thus : By the first proposition it appears, that some motion 
 must be excited in the medullary substance, during each sensa- 
 tion; by the fourth, this motion is determined to be a vibratory 
 one : since therefore some motion must also, by the second, be 
 excited in the medullary substance during the presence of each 
 idea, this motion cannot be any other than a vibratory one : else 
 how should it proceed from the original vibration attending the 
 sensation, in the same manner as the idea does from the sensa- 
 tion itself? It must also agree in kind, place, and line of direc- 
 tion, with the generating vibration. A vibratory motion, which 
 recurs t times in a second, cannot beget a diminutive one that 
 recurs f t, or 2 t times; nor one originally impressed on the 
 region of the brain corresponding to the auditory nerves, beget 
 diminutive vibrations in the region corresponding to the optic 
 nerves; and so of the rest. The line of direction must likewise 
 be the same in the original and derivative vibrations. It 
 remains therefore, that each simple idea of sensation be at- 
 tended by diminutive vibrations of the same kind, place, and 
 line of direction, with the original vibrations attending the sen- 
 sation itself: or, in the words of the proposition, that sensory 
 vibrations, by being frequently repeated, beget a disposition to 
 diminutive vibrations corresponding to themselves respect- 
 ively. We may add, that the vibratory nature of the motion 
 which attends ideas, may be inferred from the continuance of 
 some ideas, visible ones for instance, in the fancy for a few 
 moments. 
 
 PROP. X. Any Sensations A, B, C, &c. by being associated 
 with one another a sufficient Number of Times, get such a Power 
 over the corresponding Ideas a, b, c, &c. that any one of the 
 Sensations A, when impressed alone, shall be able to excite in 
 the Mind, b, c, &c. the Ideas of the rest. 
 SENSATIONS may be said to be associated together, when 
 
 their impressions are either made precisely at the same instant
 
 324 DAVID HARTLEY 
 
 of time, or in the contiguous successive instants. We may 
 therefore distinguish association into two sorts, the synchron- 
 ous, and the successive. 
 
 The influence of association over our ideas, opinions, and 
 affections, is so great and obvious, as scarcely to have escaped 
 the notice of any writer who has treated of these, though the 
 word association, in the particular sense here affixed to it, was 
 first brought into use by Mr. Locke. But all that has been 
 delivered by the ancients and moderns, concerning the power 
 of habit, custom, example, education, authority, party- 
 prejudice, the manner of learning the manual and liberal 
 arts, &c. goes upon this doctrine as its foundation, and may 
 be considered as the detail of it, in various circumstances. 
 I here begin with the simplest case, and shall proceed to 
 more and more complex ones continually, till I have ex- 
 hausted what has occurred to me upon this subject. 
 
 This proposition, or first and simplest case of association, is 
 manifest from innumerable common observations. Thus, the 
 names, smells, tastes, and tangible qualities of natural bodies, 
 suggest their visible appearances to the fancy, i.e. excite their 
 visible ideas; and, vice versa, their visible appearances impressed 
 on the eye raise up those powers of reconnoitring their names, 
 smells, tastes, and tangible qualities, which may not improperly 
 be called their ideas, as above noted ; and in some cases raise up 
 ideas, which may be compared with visible ones, in respect of 
 vividness. All which is plainly owing to the association of the 
 several sensible qualities of bodies with their names, and with 
 each other. It is remarkable, however, as being agreeable to 
 the superior vividness of visible and audible ideas, before taken 
 notice of, that the suggestion of the visible appearance from the 
 name is the most ready of any other; and, next to this, that of 
 the name from the visible appearance; in which last case, the 
 reality of the audible idea, when not evident to the fancy, may 
 be inferred from the ready pronunciation of the name. For it 
 will be shewn hereafter, that the audible idea is most commonly 
 a previous requisite to pronunciation. Other instances of the 
 power of association may be taken from compound visible and
 
 OBSERVATIONS ON MAN 325 
 
 audible impressions. Thus the sight of part of a large building 
 suggests the idea of the rest instantaneously; and the sound of 
 the words which begin a familiar sentence, brings the remaining 
 part to our memories in order, the association of the parts being 
 synchronous in the first case, and successive in the last. 
 
 It is to be observed, that, in successive associations, the power 
 of raising the ideas is only exerted according to the order in 
 which the association is made. Thus, if the impressions A , B, C, 
 be always made in the order of the alphabet, B impressed alone 
 will not raise a, but c only. Agreeably to which it is easy to 
 repeat familiar sentences in the order in which they always 
 occur, but impossible to do it readily in an inverted one. The 
 reason of this is, that the compound idea, c, b, a, corresponds to 
 the compound sensation C, B,A; and therefore requires the im- 
 pression of C, B, A, in the same manner as a, b, c, does that of 
 A, B, C. This will, however, be more evident, when we come 
 to consider the associations of vibratory motions, in the next 
 proposition. 
 
 It is also to be observed, that the power of association grows 
 feebler, as the number either of synchronous or successive im- 
 pressions is increased, and does not extend, with due force, to 
 more than a small one, in the first and simplest cases. But, in 
 complex cases, or the associations of associations, of which the 
 memory, in its full extent, consists, the powers of the mind, 
 deducible from this source, will be found much greater than any 
 person, upon his first entrance on these inquiries, could well 
 imagine. 
 
 PROP. XI. Any Vibrations, A, B, C, &c. by being associated 
 together a sufficient Number of Times, get such a Power over 
 a, b, c, &*c. the corresponding Miniature Vibrations, that any 
 of the Vibrations A, when impressed alone, shall be able to 
 excite b, c, &c. the Miniatures of the rest. 
 THIS proposition may be deduced from the foregoing, in the 
 
 same manner as the ninth has been from the eighth. 
 
 But it seems also deducible from the nature of vibrations, 
 
 and of an animal body. Let A and B be two vibrations, asso-
 
 326 DAVID HARTLEY 
 
 dated synchronically. Now, it is evident, that the vibration A 
 (for I will, in this proposition, speak of A and B in the singular 
 number, for the sake of greater clearness) will, by endeavouring 
 to diffuse itself into those parts of the medullary substance which 
 are affected primarily by the vibration B, in some measure 
 modify and change B, so as to make B a little different from what 
 it would be, if impressed alone. For the same reasons the vibra- 
 tion A will be a little affected, even in its primary seat, by the 
 endeavour of B to diffuse itself all over the medullary sub- 
 stance. Suppose now the vibrations A and B to be impressed at 
 the same instant, for a thousand times; it follows, from the 
 ninth proposition, that they will first overcome the disposition 
 to the natural vibrations N, and then leave a tendency to them- 
 selves, which will now occupy the place of the original natural 
 tendency to vibrations. When therefore the vibration A is im- 
 pressed alone, it cannot be entirely such as the object would 
 excite of itself, but must lean, even in its primary seat, to the 
 modifications and changes induced by B, during their thousand 
 joint impressions; and therefore much more, in receding from 
 this primary seat, will it lean that way; and when it comes to 
 the seat of B, it will excite B's miniature a little modified 
 and changed by itself. 
 
 Or thus: When A is impressed alone, some vibration must 
 take place in the primary seat of J5, both on account of the heat 
 and pulsation of the arteries, and because A will endeavour to 
 diffuse itself over the whole medullary substance. This cannot 
 be that part of the natural vibrations N, which belongs to this 
 region, because it is supposed to be overruled already. It can- 
 not be that which A impressed alone would have propagated 
 this region, because that has always hitherto been overruled, 
 and converted into B; and therefore cannot have begotten a 
 tendency to itself. It cannot be any full vivid vibration, such 
 as B, C, D, &c. belonging to this region, because all full vibra- 
 tions require the actual impression of an object upon the corre- 
 sponding external organ. And of miniature vibrations belong- 
 ing to this region, such as b, c, d, &c. it is evident, that b has the 
 preference, since A leans to it a little, even in its own primary
 
 OBSERVATIONS ON MAN 327 
 
 seat, more and more, in receding from this, and almost entirely, 
 when it comes to the primary seat of B. For the same reasons 
 B impressed alone will excite a; and, in general, if A, B, C, &c. 
 be vibrations synchronically impressed on different regions of 
 the medullary substance, A impressed alone will at last excite 
 b, c, &c. according to the proposition. 
 
 If A and B be vibrations impressed successively, then will the 
 latter part of A, viz. that part which, according to the third and 
 fourth propositions, remains, after the impression of the object 
 ceases, be modified and altered by B, at the same time that it 
 will a little modify and alter it, till at last it be quite over- 
 powered by it, and end in it. It follows therefore, by a like 
 method of reasoning, that the successive impression of A and B, 
 sufficiently repeated, will so alter the medullary substance, as 
 that when A is impressed alone, its latter part shall be not such 
 as the sole impression of A requires, but lean towards B, and 
 end in b at last. But B will not excite a in a retrograde order; 
 since, by supposition, the latter part of B was not modified and 
 altered by A , but by some other vibration, such as C or D. And 
 as B, by being followed by C, may at last raise c; so b, when 
 raised by A, in the method here proposed, may be also suffi- 
 cient to raise c; inasmuch as the miniature c being a feeble mo- 
 tion, not stronger, perhaps, than the natural vibrations N, 
 requires only to have its kind, place, and line of direction, de- 
 termined by association, the heat and arterial pulsation con- 
 veying to it the requisite degree of strength. And thus A im- 
 pressed alone will raise b, c, &c. in successive associations, 
 as well as in synchronous ones, according to the proposi- 
 tion. 
 
 It seems also, that the influence of A may, in some degree, 
 reach through B to C; so that A of itself may have some effect 
 to raise c, as well as by means of b. However, it is evident, that 
 this chain must break off, at last, in long successions; and that 
 sooner or later, according to the number and vigour of the 
 repeated impressions. The power of miniature vibrations to 
 raise other miniatures may, perhaps, be made clearer to mathe- 
 maticians, by hinting, that the efficacy of any vibration to raise
 
 328 DAVID HARTLEY 
 
 any other, is not in the simple ratio of its vividness, but as some 
 power thereof less than unity; for thus b may raise c, a weaker 
 vibration than b, c may raise d, &c. with more facility than if 
 the efficacy was in the simple ratio of the vividness, and yet so 
 that the series shall break off at last. 
 
 If the ninth proposition be allowed, we may prove this in 
 somewhat a shorter and easier manner, as follows. Since the 
 vibrations A and B are impressed together, they must, from the 
 diffusion necessary to vibratory motions, run into one vibration ; 
 and consequently, after a number of impressions sufficiently 
 repeated, will leave a trace, or miniature, of themselves, as one 
 vibration, which will recur every now and them, from slight 
 causes. Much rather, therefore, may the part b of the com- 
 pound miniature a + b recur, when the part A of the compound 
 original vibration A +B is impressed. 
 
 And as the ninth proposition may be thus made to prove the 
 present, so it ought to be acknowledged and remarked here, 
 that unless the ninth be allowed, the present cannot be proved, 
 or that the power of association is founded upon, and necessa- 
 rily requires, the previous power of forming ideas, and miniature 
 vibrations. For ideas, the miniature vibrations, must first be 
 generated, according to the eighth and ninth propositions, 
 before they can be associated, according, to the tenth and this 
 eleventh. But then (which is very remarkable) this power of 
 forming ideas, and their corresponding miniature vibrations, 
 does equally presuppose the power of association. For since all 
 sensations and vibrations are infinitely divisible, in respect of 
 time and place, they could not leave any traces or images of 
 themselves, i.e. any ideas, or miniature vibrations, unless their 
 infinitesimal parts did cohere together through joint impres- 
 sion, i.e. association. Thus, to mention a gross instance, we 
 could have no proper idea of a horse, unless the particular ideas 
 of the head, neck, body, legs, and tail, peculiar to this animal, 
 stuck to each other in the fancy, from frequent joint impres- 
 sion. And, therefore, in dreams, where complex associations are 
 much weakened, and various parcels of visible ideas, not joined 
 in nature, start up together in the fancy, contiguous to each
 
 OBSERVATIONS ON MAN 329 
 
 other, we often see monsters, chimeras, and combinations, 
 which have never been actually presented. 
 
 PROP. XII. Simple Ideas will run into complex ones, by 
 Means of Association. 
 
 IN order to explain and prove this proposition, it will be 
 requisite to give some previous account of the manner in 
 which simple ideas of sensation may be associated together. 
 
 Case i. Let the sensation A be often associated with each of 
 the sensations B, C, D, &c. i.e. at certain times with B, at cer- 
 tain other times with C, &c. it is evident, from the tenth propo- 
 sition, that A, impressed alone, will, at last, raise b, c, d, &c. all 
 together, i.e. associate them with one another, provided they 
 belong to different regions of the medullary substance; for if 
 any two, or more, belong to the same region, since they cannot 
 exist together in their distinct forms, A will raise something 
 intermediate between them. 
 
 Case 2. If the sensations A, B, C, D, &c. be associated to- 
 gether, according to various combinations of twos, or even 
 threes, fours, &c. then will A raise b, c, d, &c. also B raise a, c, d, 
 &c. as in case the first. 
 
 It may happen, indeed, in both cases, that A may raise a par- 
 ticular miniature, as b, preferably to any of the rest, from its 
 being more associated with B, from the novelty of the impres- 
 sion of B, from a tendency in the medullary substance to favour 
 b, &c. and in like manner, that b may raise c or d preferably to 
 the rest. However, all this will be overruled, at last, by the 
 recurrency of the associations; so that any one of the sensations 
 will excite the ideas of the rest at the same instant, i.e. associate 
 them together. 
 
 Case 3. Let A, J5, C, D, &c. represent successive impressions, 
 it follows from the tenth and eleventh propositions, that A will 
 raise b, c, d, &c. B raise c, d, &c. And though the ideas do not, 
 in this case, rise precisely at the same instant, yet they come 
 nearer together than the sensations themselves did in their 
 original impression; so that these ideas are associated almost
 
 330 DAVID HARTLEY 
 
 synchronically at last, and successively from the first. The 
 ideas come nearer to one another than the sensations, on ac- 
 count of their diminutive nature, by which all that appertains 
 to them is contracted. And this seems to be as agreeable to 
 observation as to theory. 
 
 Case 4. All compound impressions A+B+C+D, &c. after 
 sufficient repetition leave compound miniatures a+b+c+d, 
 &c. which recur every now and then from slight causes, as well 
 such as depend on association, as some which are different from 
 it. Now, in these recurrences of compound miniatures, the 
 parts are farther associated, and approach perpetually nearer 
 to each other, agreeably to what was just now observed; i.e. the 
 association becomes perpetually more close and intimate. 
 
 Case 5. When the ideas a, b, c, d, &c. have been sufficiently 
 associated in any one or more of the foregoing ways, if we sup- 
 pose any single idea of these, a for instance, to be raised by the 
 tendency of the medullary substance that way, by the associa- 
 tion of A with a foreign sensation or idea X or x, &c. this idea a, 
 thus raised, will frequently bring in all the rest, b, c, d, &c. and 
 so associate all of them together still farther. 
 
 And upon the whole, it may appear to the reader, that the 
 simple ideas of sensation must run into clusters and combina- 
 tions, by associations; and that each of these will, at last, coal- 
 esce into one complex idea, by the approach and commixture 
 of the several compounding parts. 
 
 It appears also from observation, that many of our intel- 
 lectual ideas, such as those that belong to the heads of beauty, 
 honour, moral qualities, &c. are, in fact, thus composed of 
 parts, which, by degrees, coalesce into one complex idea.
 
 CHARLES BONNET 
 
 (1720-1793) 
 
 ABSTRACT OF THE ANALYTICAL ESSAY 
 UPON THE FACULTIES OF THE SOUL 
 
 Translated from the French* by 
 BENJAMIN RAND 
 
 I. The senses the first source of our ideas 
 
 I HAVE set out from a well known and indubitable fact, and 
 one which no person will venture to deny. It is that one born 
 blind can never acquire our ideas of light and colors. 1 His soul 
 has however the same faculties as ours. What then does he 
 lack in order to have these visual sensations ? the organ 
 suitable to these sensations. 
 
 Suppose the person born blind were at the same time bom 
 deaf, and had also from his birth been deprived of the senses of 
 touch, taste, and smell. I ask what ideas his soul would be able 
 to acquire? 
 
 The reply will possibly be made to me as it already has been, 
 that it would have at least the consciousness of its existence. 
 But how do we acquire the consciousness of our own existence? 
 Is it not by reflecting upon our own sensations? Or at least are 
 not our first sensations united to that consciousness, which 
 our soul always has that it is itself which experiences them? 
 And is this consciousness anything else than that of its exist- 
 ence? But how could a soul which has never had a sensation 
 know that it exists? 
 
 It would not be well to admit here a certain confused con- 
 sciousness of existence of which we could not form any idea. It 
 
 * Ch. Bonnet's Essai Analytique sur les facultes de I'dme. Copenh. 1760. 
 Translated here from Bonnet's Analyse abregee de I'essai analytique (1769), in 
 his Oeuvres d'histoire naturelle et de philosophic. Neufchatel, 1779-83, torn. xv. 
 
 1 Bonnet's Essai analytique sur les facultes de I'dme, 17.
 
 332 CHARLES BONNET 
 
 is better doubtless to receive only clear things and those about 
 which one can reason. The present thought cannot constitute 
 the essence of the soul. What would constitute it, at least 
 partly, would be rather the capacity for thoughts (cogitabilite ) . 
 
 II. Reflection, the second source of our ideas 
 
 I HAVE thus supposed as a principle that all our ideas are 
 derived originally from the senses. I have not said that our 
 ideas are purely sensory. I have shown very clearly and in great 
 detail, how reflection aided by the different kinds of signs rises 
 by degrees from sensations to the most abstract conceptions. 1 I 
 have sufficiently investigated the theory of abstractions, and 
 have traced in general that of ideas. 2 
 
 III. The union of soul and body and its law 
 
 THE objects themselves or the corpuscles which emanate 
 from them act upon the senses only by impulsion. They com- 
 municate to them a certain shock, which is transmitted to 
 the brain, and the soul experiences sensations. 
 
 The philosopher does not investigate how the movement of a 
 nerve causes an idea to arise in the soul. He simply admits the 
 fact and readily renounces the attempt of discovering the cause. 
 He knows that it springs from the mystery of -the union of two 
 substances, and that this mystery is for him inscrutable. 
 
 It suffices for him to know that to the disturbance of this or 
 that nerve there always corresponds in the soul this or that 
 sensation. He does not regard the sensation as the physical 
 and immediate effect of the movement of the nerve, but as the 
 inseparable sequence of that movement. He regards this move- 
 ment as in some sort a natural sign of the sensation by divine 
 establishment. 
 
 IV. Man a composite being 
 
 I HAVE not affirmed that it is impossible for the soul to think 
 without a body. There perhaps exist pure spirits which have 
 ideas; but I am profoundly ignorant how they have them. 
 1 Chaps, xvi, xix, 28. 2 Chaps, xiv, xv, xvi.
 
 THE FACULTIES OF THE SOUL 333 
 
 I know only that the feeling that I have of my ego is always 
 one, simple, indivisible; from which I infer that I am not 
 wholly material. I have very much amplified this excellent 
 proof. I admit then the existence of my soul as that of an 
 immaterial substance, which it has pleased the Creator to unite 
 to an organised body. I learn from the contemplation of my 
 being, that I result from the union of two very different sub- 
 stances. 
 
 In this order of things I perceive that I have ideas only by 
 the intervention of my body, and the more I reflect upon my- 
 self, the more I am compelled to recognise the great influence 
 of the machine 1 upon all the operations of my soul. 
 
 I learn also from revelation that my soul will be eternally 
 joined to a portion of matter. I shall therefore be eternally a 
 composite being. 
 
 The purpose of the author of my being has therefore not been 
 that I should be a pure spirit. He has consequently willed that 
 my soul should use its faculties only by means of a body. If he 
 had willed otherwise I should have philosophized differently, 
 because I should have had another way of perceiving and 
 judging. 
 
 I have thus followed in my researches upon the economy of 
 our being the course which has appeared to me most to conform 
 to that of nature. My soul has no hold upon itself; it cannot see 
 itself, and it cannot feel itself; but it sees, and it feels bodies, by 
 the aid of the body to which it is united. 
 
 Its senses place it in relation with everything about it; 
 through them it is related to all parts of the universe; by 
 them it appropriates in some fashion all of nature, and even 
 reascends to its divine author. 
 
 V. The objects of our sensations real 
 
 I studied then the constitution of my senses, which are the 
 
 universal instruments of the operations of my soul. I gave 
 
 attentive heed to everything that takes place in them when 
 
 objects happen to strike them. I meditated upon the effects of 
 
 1 The group of organs which constitute the body of man.
 
 334 CHARLES BONNET 
 
 those shocks, and upon the relationship that the fibres, which 
 are the seat of them, sustain with one another, and on the most 
 immediate consequences of these relationships. 
 
 As I was assured that my soul experiences no modification, 
 except upon occasion of something which happens to and 
 through its senses to that part of the brain which is the imme- 
 diate seat of feeling and of thought, I considered the play and 
 modifications of the sensory fibres as a sort of representation of 
 the corresponding modifications of my soul. 
 
 It is of very little importance for my purpose that I do not 
 err about the existence of bodies. Although the whole material 
 system should be only a phenomenon, a pure appearance, rela- 
 tive to my manner of perceiving and of judging, I should none 
 the less distinguish my sensations from one another. I would 
 not be the less assured that some are in my power, arid that 
 others are not- at all. I would also be none the less certain that 
 there exists apart from my soul something which excites in it 
 sensations independent of its will. That thing, whatever it may 
 be, is what I term matter. 
 
 I do not affirm that matter is in effect what it seems to me to 
 be; but I can reasonably affirm, that what seems to be results 
 essentially, both from that which it is itself, as well as from what 
 I am by reference to it. Beings which observe it under other 
 relationships than mine are of a different nature from mine. I 
 would see myself under other relationships, if my nature hap- 
 pened to change. 
 
 It would also be wholly indifferent to the purpose of my 
 researches to discuss the different hypotheses which have been 
 made in order to explain the union of the soul and of the body, 
 since all such hypotheses equally suppose a constant relation- 
 ship between the modifications of the soul and the movements 
 of the body. 
 
 It was necessary then always to devote one's attention to the 
 play of the organs. It is fully permitted afterward to translate 
 every reasoning into the special language of the hypothesis 
 that has been adopted. I have confined myself to physical in- 
 fluence, not as a fact, but as that which seems to be.
 
 THE FACULTIES OF THE SOUL 335 
 
 VI. Specific differences of the sensory fibres 
 
 EACH sense has its mechanics, its manner of action, its end. 
 Each sense transmits to the soul a multitude of different im- 
 pressions to which correspond a like number of different sen- 
 sations. 
 
 It was not possible for me to conceive of fibres perfectly 
 similar being capable of receiving and transmitting without 
 confusion so many diverse impressions. It has seemed to me, 
 that each sensory fibre would in such a case be like a body 
 impelled at the same time by several forces acting in different 
 directions. This body would thereby receive a composite move- 
 ment which would be the product of those forces, and which 
 would represent none of those forces in particular. 
 
 In assuming this point of view I have not been able to render 
 an account to myself of the difference in my sensations. I have, 
 therefore, been compelled to suppose that there is in each sense 
 certain fibres appropriate to each kind of sensation. 
 
 I believe that I have discerned in the organisation of the 
 senses peculiarities which justify my supposition, and I have 
 indicated them. 1 The observations upon the difference of 
 refrangability of colored rays, and upon those of the vibrations 
 of strings of musical instruments, have appeared to me to add 
 an additional degree of probability to that conjecture. 
 
 VII. The physics of reminiscence 
 
 BUT my soul is not limited to feeling through the agency of 
 my senses. It has likewise recollection of that which it has felt. 
 It has the consciousness of the newness of a sensation. A sensa- 
 tion which has been presented to it many times does not affect 
 it precisely as at the first time. 
 
 It is always through the senses that objects come to the soul. 
 Those fibres which have been shocked many times cannot be 
 precisely in the state in which they were before they had been 
 disturbed. The repeated action of the object must change 
 them in some respect. 
 
 If a particular kind of sensation has been associated with a 
 1 Chap. viii.
 
 336 CHARLES BONNET 
 
 special kind of fibre, the recollection of the sensation, or the 
 reminiscence, may have been associated with the present state 
 of the fibre. I have thus conjectured that the virgin fibres do 
 not affect the soul precisely as those do which are not so, and I 
 have attributed the feeling of novelty to that state of virginity 
 of the sensory fibres. 1 
 
 By virtue of the union of the two substances nothing can take 
 place in the soul without something in the body correspond- 
 ing to it. It is this something which I have always sought, 
 though I do not flatter myself to have always encountered, 
 and that very often I have only caught a glimpse of it. 
 
 VIII. The action of the soul upon the Senses indicated by the 
 nature and effects of the attention 
 
 MY soul has a will, and exerts it. It has certain desires, and 
 is active. This activity, whatever may be its nature, must have 
 a subject on which it displays itself. It has not been possible 
 for me to discover for it any other than the sensory fibres. I 
 have therefore thought that as the senses act upon the soul, so 
 the soul may act in its turn upon the senses. 
 
 I have not said that the soul acts after the manner of the 
 body, as it is not body; but I have said that the effect of its 
 action corresponds to that of a body. In one word I have 
 admitted, that the soul causes the sensory fibres to vibrate at 
 its pleasure, and I have not undertaken to investigate the man- 
 ner of it. 
 
 Divers facts have appeared to me to establish that motive 
 power of the soul, and in particular the exercise of attention. 
 When it is too long continued, it gives rise in the soul to that 
 uncomfortable feeling, which we express by the term fatigue. 
 
 Strictly speaking can fatigue have its seat anywhere else 
 than in the organs? And is it not the soul itself, which occasions 
 fatigue, by an act of its will? If it did not will to be atten- 
 tive, it would not experience any fatigue. It acts, therefore, 
 upon the fibres which are the seat of this fatigue. 
 
 If the fatigue ceases when the soul changes its object, that is 
 1 Chap. ix.
 
 THE FACULTIES OF THE SOUL 337 
 
 because it is acting upon other fibres. For we have seen, that 
 it is probable, that every object has in the brain certain fibres 
 which are adapted to it. 
 
 It is by the aid of these principles that I, perhaps the first, 
 have attempted to analyze the nature, and the effects of atten- 
 tion, and to prove that it is this valuable faculty which estab- 
 lishes the most difference between one man and another. 1 
 
 Excellent rules have been given us for directing and fixing 
 the attention ; but sufficient investigation has not been made of 
 the physical foundation of these rules. You will never succeed 
 better in guiding man, than when you set out from the physical 
 constitution. It is always through the physical that you must 
 pass to reach the soul. 
 
 IX. The physics of the imagination and of the memory 
 
 THE ideas that objects excite in the soul can be recalled by 
 it without the intervention of objects. This reproduction of 
 ideas is due to imagination, and to memory. I have sought to 
 investigate how they operate, or what is the same thing, wherein 
 consists the physics of the imagination, and of the memory. 2 
 
 The method, that I have followed to succeed, has seemed to 
 me very simple and sufficiently luminous. It is the same that 
 I have pursued in all my psychological researches. I have at 
 first directed my attention to what has immediately preceded. 
 Before investigating how an idea is reproduced, I have investi- 
 gated how it was produced. 
 
 I have clearly seen that the soul never has a new sensation, 
 except through the medium of the senses. It is to the shock of 
 certain fibres that such sensation has been originally as- 
 sociated. Its reproduction or its recall by imagination will still 
 be related to the shock of these same fibres. 
 
 Accidents, which can effect only the body, enfeeble and even 
 destroy the imagination and the memory. They have therefore 
 their seat in the body. And how could this seat be anything else 
 than the organs which transmit to the soul all outer impressions. 
 
 1 Chaps, xi, xix, 628, 530, 533. 
 
 2 Chap, xiv, 212, 213, 214; chap, xx, 546; chap, xxn, 623,624.
 
 338 CHARLES BONNET 
 
 It is therefore my belief that the sensory fibres are constituted 
 in such a manner, that the action more or less continued of the 
 objects produces on them determinations more or less durable, 
 which constitute the physics of memory. 
 
 I have never been able to say what these determinations are, 
 because the structure of the sensory fibres is to me unknown. 
 But if sense has its mechanics, I have thought that every kind 
 of sensory fibre can also have its own. 
 
 X. Important remarks upon the sensory fibres 
 
 I HAVE thus regarded each sensory fibre as a very small 
 organ, which has its own functions, or as a very small machine, 
 which the action of the objects keys to the tone which is 
 adapted to it. I have judged that the play or the conduct of the 
 fibre must result essentially from its primordial structure, and 
 this latter from the nature and arrangement of the elements. 
 
 It is impossible for me to represent these elements as of the 
 nature of simple bodies. I have regarded them as constituent 
 parts of a small organ, or as the different parts of a small 
 machine, designed to receive, to transmit, and to reproduce the 
 impression of the object to which it has been adapted. 
 
 I have therefore supposed that every kind of sensory fibre 
 has been originally patterned upon relationships that are 
 adapted to the manner of acting of its object. 
 
 This supposition has not appeared to me gratuitous. If the 
 eye does not act as the ear, it is because its structure is essen- 
 tially different, because light does not act like sound. The 
 fibres appropriate to different visual sensations have therefore 
 probably another structure than that of fibres adapted to per- 
 ceptions of hearing. 
 
 Nay more: each perception has its peculiar character which 
 makes us distinguish it from every other. For example, every 
 colored ray has an essence which is unchangeable. A red ray 
 for instance does not act precisely as a blue ray. There are con- 
 sequently still among the fibres of vision certain differences 
 corresponding to those which exist among the rays. 
 
 I have not simply admitted that the fibres of sight are finer
 
 THE FACULTIES OF THE SOUL 339 
 
 than those of hearing; that the vibrations of one are more 
 prompt than those of the other; and that among the fibres of 
 sight those which are adapted to the action of red rays are less 
 'fine than those which are suited to the action of blue rays. This 
 does not appear to me sufficient to render an account of the 
 phenomena of memory. 
 
 I have indeed surmised that oscillations more or less rapid, 
 or other analogous movements, might perhaps suffice to 
 characterize the kind of sensation. I have not, however, under- 
 stood that they can at the same time serve to recall to the soul 
 the memory of the sensation. It has seemed to me that since 
 this memory is connected with the body, it must depend upon 
 some change which happened to the primitive state of the 
 sensory fibres through the action of objects. 1 
 
 I have, therefore, admitted as probable that the state of the 
 fibres upon which an object has acted, is not precisely the same 
 after that action, as it was before. I have conjectured that the 
 sensory fibres thus experience modifications more or less dur- 
 able, which constitutes the physics of recollection, and of 
 memory. 
 
 I have not undertaken to determine in what these modifica- 
 tions consist. I know no fact which could throw light upon this 
 obscure point. But having regarded the sensory fibres as very 
 small organs, it has not been difficult for me to conceive that 
 the constituent parts of these organs may assume with reference 
 to one another new positions, or new relationships, to which 
 was attached the physics of memory. 
 
 This is the result of habit, of which so much is said, which 
 has so great an influence in human life, and of which I am not 
 aware that anyone has well developed the principle. I have 
 endeavored to explain how it is formed, rooted, weakened, and 
 obliterated. 2 
 
 I have said on that occasion, " not only does the fibre transmit 
 to the soul the impression of the object, but it recalls to it 
 furthermore the recollection of this impression. This remem- 
 
 1 Chap, vii, 57, 58, 59. 
 
 2 Chap, ix, p. 96, 97, etc.; chap, xxu, p. 641, 642, etc.
 
 34 o CHARLES BONNET 
 
 brance differs from the sensation itself only in the degree of its 
 intensity. It has therefore the same origin. It depends then as 
 the sensation itself upon a movement which is aroused in the 
 fibre; but on a weaker movement. 
 
 The carrying out of this movement requires a certain dispo- 
 sition in the integral parts of the fibre. The elements, therefore, 
 retain during a period of more or less length, the determinations 
 which they have received from the action of the object. It 
 keys up, so to speak, the fibre to its own tone, and while the 
 fibre remains keyed up in this way, it preserves the power of 
 recalling to the soul the memory of the sensation of the object." 
 
 I added finally: "It is necessary therefore to regard the 
 fibre as a very small machine designed to produce a certain 
 movement. The capacity of this small machine to carry out 
 that movement depends originally upon its construction; and 
 that construction differentiates it from every other machine of 
 the same sort. The action of the object makes this capacity 
 active. It is that action which keys up the machine. As soon as 
 it is keyed up it plays at the moment that some impulse 
 occurs." 
 
 For the rest, the reader ought not to have much difficulty in 
 understanding, how nature has been able to vary sufficiently 
 the structure of sensory fibres to provide for that prodigious 
 diversity of perceptions which we experience. How much human 
 art, so crude, so imperfect, so limited, varies its productions of 
 the same kind ! How many different forms has it not been able 
 to give to a chain ! What variety has it not put among the links 
 of different chains! Of how many combinations are not the 
 same elements susceptible ! And how will it be when we suppose 
 the elements have been themselves diversified !
 
 feTIENNE BONNOT DE CONDILLAG 
 
 (1715-1780) 
 
 TREATISE ON SENSATIONS 
 
 Translated from the French * by 
 FREDERICK C. DE SUMICHRAST 
 
 CHAPTER!. THE FIRST NOTIONS OF A MAN 
 POSSESSING THE SENSE OF SMELL ONLY 
 
 i. THE notions of our statue being limited to the sense of 
 smell, can include odours only. It cannot have any conception 
 of extent, of form, of anything external to itself, or to its sensa- 
 tions, any more than it can have of colour, sound or taste. 
 
 2. If we offer the statue a rose, it will be, in its relation to us, 
 a statue which smells a rose; but in relation to itself, it will be 
 merely the scent itself of the flower. 
 
 Therefore, according to the objects which act upon its organ, 
 it will be scent of rose, of carnation, of jasmine, of violet. In a 
 word, odours are, in this respect, merely modifications of the 
 statue itself or modes of being; and it is not capable of believ- 
 ing itself aught else, since these are the only sensations it can 
 feel. 
 
 3. Let those philosophers to whom it is so evident that every- 
 thing is material, put themselves for a moment in the place of 
 the statue, and let them reflect how they could suspect that there 
 exists anything resembling what we call matter. 
 
 4. We may then already be convinced that it is sufficient to 
 increase or to diminish the number of the senses to cause us to 
 come to conclusions wholly different from those which are at 
 present so natural to us, and our statue, limited to the sense of 
 smell, may thus enable us to comprehend somewhat the class 
 of beings whose notions are the most restricted. 
 
 * From Trait& des Sensations, Paris and London, 1754.
 
 342 CONDILLAC 
 
 CHAPTER II. OF THE OPERATIONS OF THE 
 MIND IN A MAN LIMITED TO THE SENSE OF 
 SMELL, AND OF THE FACT THAT THE DIF- 
 FERENT DEGREES OF PLEASURE AND OF PAIN 
 CONSTITUTE THE PRINCIPLE OF THESE OP- 
 ERATIONS. 
 
 1. With the first odour the capacity for feeling of our statue 
 wholly taken up by the impression made upon its organ. I 
 
 call this attention. 
 
 2. From that moment it begins to enjoy or to suffer: for if the 
 ower of feeling is wholly devoted to a pleasant odour, enjoy- 
 
 ent is the result ; and if it be wholly devoted to an unpleasant 
 odour, suffering results. 
 
 3. But our statue has yet no idea of the different changes it 
 may experience. Therefore it is well; or it is not well, without 
 the desire to be better. Suffering is no more capable of exciting 
 in the statue a longing for an enjoyment of which it has no know- 
 ledge, than enjoyment is capable of making it fear an ill of which 
 it is equally ignorant. Consequently, no matter how disagree- 
 able the first sensation may be, even to the point of wounding 
 the organ and of being a violent pain, it cannot cause desire. 
 
 While suffering with us is always accompanied by the desire 
 not to suffer, it cannot be so with the statue. Pain creates that 
 desire in us only because the condition of non-suffering is al- 
 ready known to us. The habit we have contracted of looking 
 upon pain as a thing we have been without and of which we may 
 be freed, is the cause that the moment we suffer we immediately 
 desire not to suffer, ansLtJiis ponditionJis inseparable irony a 
 state of suffering. 
 
 But the statue which, at the first moment, is conscious of its 
 feeling only through the very pain it experiences, does not know 
 whether it can cease to be a statue and become something 
 else, or cease to exist. It has, as yet, no conception of change, 
 of succession or of duration. Therefore it exists without having 
 the power to form a desire.
 
 TREATISE ON SENSATIONS 343 
 
 4. Once it has observed that it is capable of ceasing to be 
 what it is, in order to become once more what it was before, we 
 shall see its desires spring from a condition of pain, which it 
 will compare with a condition of pleasure recalled to it by mem- 
 ory. Thus it is that pleasure and pain are the sole principle 
 which, determining all the operations of its soul, will gradually 
 raise it to all the knowledge of which it is capable; and in order 
 to determine the progress of which it is susceptible, it will suffice 
 to observe the pleasure it will have to desire, the pains it will 
 have to fear, and the influence of either according to circum- 
 stances. 
 
 5. Supposing the statue to have no remembrance of the 
 changes it has undergone, then on every occasion of a change 
 it would believe itself to be conscious of sensation for the first 
 time: whole years would be swallowed up in each present mo- 
 ment. Therefore by ever confining its attention to a single mode 
 of being, it would never reckon two together, and would never 
 note their relations to each other: it would enjoy or suffer, with- 
 out yet knowing desire or fear. 
 
 6. But the odour it smells does not, so soon as the odoriferous 
 object ceases to act upon its organ, become wholly lost to the 
 statue. "The attention it bestowed upon it still retains the odour, 
 and there remains a more or less strong impression of that odour 
 in proportion as the attention itself has been more or less active. 
 That is memory. Jp^yfi^* 7 
 
 7. When, therefore, our statue is* a new odour, there is still 
 present to it the odour that it was the moment before. Its power ^ 
 of feeling is divided between memory and the sense of smell, 
 the former of these faculties being attentive to the past sensation, 
 while the latter is attentive to the present sensation. 
 
 8. Thus there are in the statue two modes of feeling, differ- 
 ing only in this, that the one is concerned with a present sensa- 
 tion and the other with a sensation no longer existent, but the 
 impression of which still remains. Unaware of the fact that there 
 are objects which act upon it, unaware even of the fact that it 
 possesses an organ, the statue ordinarily distinguishes between 
 the remembrance of a sensation and a present sensation merely
 
 344 CONDILLAC 
 
 by dimly feeling what it has been and feeling strongly what it is 
 at the moment. 
 
 9. I say ordinarily, because remembrance will not always be 
 a faint sentiment, nor sensation a lively one. For every time 
 that memory recalls very strongly these states of being, while, 
 on the contrary, the organ itself receives but slight impressions, 
 the consciousness of a present sensation will be much less vivid 
 than the remembrance of a sensation which has ceased to be. 
 
 10. As, therefore, one odour is present to the sense of smell 
 through the impression made by an odoriferous body upon the 
 organ itself, so is another odour present in the memory, because 
 the impression made by another odoriferous body continues in 
 the brain, to which the organ of smell has transmitted it. Pass- 
 ing thus through two states of being, the statue feels that it is 
 no longer what it has been : the knowledge of this change causes 
 it to refer the first state to a different moment from that in which 
 it experiences the second state, and this it is which causes the 
 statue to make a distinction between existing in one way and 
 having existed in another way. 
 
 11. The statue is active in relation to one of its two modes of 
 feeling, and passive in relation to the other. IMs active when it 
 remembers a sensation, because it has within itself the cause 
 which brings about that recollection, that is memory. It is 
 passive at the moment when it experiences a sensation, because 
 the cause which produces it is external to the statue itself, that 
 is, it lies in the odoriferous bodies which act upon its sense of 
 smell. 
 
 12. But, unable even to suspect the action upon itself of ob- 
 jects external to it, it cannot distinguish between a cause within 
 itself and a cause outside of itself. As far as the statue is con- 
 cerned all the modifications of its state of being appear to it due 
 to itself, and whether it experiences a sensation or merely recalls 
 one, it is never aware of aught save that it is or has been in such 
 and such a state of being. It cannot, therefore, observe any 
 difference between the condition in which it is itself active or 
 that in which it is wholly passive. 
 
 13. Nevertheless the more numerous the occasions for the
 
 TREATISE ON SENSATIONS 345 
 
 exercise of the memory the more readily will the memory act. 
 And it is in this way that the statue will acquire the habit of re- 
 calling without an effort the changes through which it has passed, 
 and of dividing its attention between what it has been and what 
 it is. For habit is merely the facility of repeating what one has 
 done, and that facility is acquired by the reiteration of the ac- 
 tions. 
 
 14. If, after having repeatedly smelled a rose and a carnation, 
 the statue once more smells a rose, the passive attention, acting 
 by the sense of smell, will be wholly given up to the present odour 
 of the rose, and the active attention, which acts through the 
 memory, will be divided between the remains of the scents of 
 the rose and of the carnation. Now these two states of being 
 cannot share the capacity for feeling without comparing them- 
 selves one with the other, for comparing is nothing else than 
 bestowing one's attention upon two ideas at tkc same tinUK Jt&A* 
 
 15. From the moment that comparison exists, judgment exists. 
 Our statue cannot at one and the same time be attentive to the 
 sr^nt of the rose and that of the carnation, without perceiving 
 that the one is not the same as the other, and it cannot be atten- 
 tive to the odour of a rose which it smells and to that of a rose 
 which it has previously smelled without perceiving that they are a 
 similar modification. Judgment, therefore, is simply the percep- 
 tion of the relation between two ideas which are being compared. 
 
 1 6. As the comparisons and conclusions become more fre- 
 quent the statue acquires greater facility in making them. It 
 contracts theBefore the habit of comparing and judging. Con- 
 sequently it will be sufficient to make it smell other odours in 
 order to cause it to make additional comparisons, come to ad- 
 ditional conclusions and contract new habits. 
 
 17. The first sensation it experiences causes no surprise to 
 the statue, for it is as yet unaccustomed to form any kind of 
 judgment, nor is it surprised when, on smelling successively 
 different odours, it perceives each but for a moment. Under 
 these conditions it does not abide by any conclusion it has formed, 
 and the more the statue changes the more it feels itself naturally 
 inclined to change.
 
 346 CONDILLAC 
 
 Nor will it feel any more surprise if we lead it, by unnotice- 
 able gradations, from the habit of believing itself one odour to 
 the conclusion that it is another odour, for the statue changes 
 without having the power of noticing the change. 
 
 But it cannot fail to be surprised if it passes suddenly from a 
 condition to which it was accustomed to a totally different state 
 of which it had no previous conception. 
 
 1 8. This amazement causes it to feel more distinctly the differ- 
 ences between its modes of being. The more abrupt the change 
 from one to the other the greater the astonishment of the statue, 
 and the more is it struck by the contrast between the pleasures 
 and the pains which mark these changes. Its attention, excited 
 by pains which are more keenly felt, applies itself with greater 
 acuteness to the sensations which succeed each other. It there- 
 fore compares them more carefully; it judges more accurately 
 their relations to each other. Amazement consequently increases 
 the activity of the operations of its mind. But, because it is 
 by bringing out a more marked opposition between feelings of 
 pleasure and feelings of pain that amazement thus increases 
 activity of mind, it follows that it is always pleasure artd pain 
 which are the primary motive cause of its faculties. 
 
 19. If each successive odour acts with equal force upon the 
 statue's attention, the memory will remember them in the order 
 in which they followed each other, and they will by this means 
 become connected one with another. 
 
 If the series is numerous, the impression made by the most 
 
 ^ v recent odours, being the most recent, will be the strongest; the 
 
 impression made by the first in order will be imperceptibly 
 
 weakened, then disappear altogether, and these sensations will 
 
 be as if they had never been. 
 
 But if there be any which have acted but slightly upon the 
 attention, they will leave no impression behind them and will 
 be forgotten as soon as they have been perceived. 
 
 Finally the impressions which will have more vividly struck 
 the attention, will be more vividly recalled, and will so strongly 
 engage it that they will be capable of making it forget the others. 
 
 20. Memory therefore is a series of ideas forming a sort of
 
 TREATISE ON SENSATIONS 347 
 
 chain. It is this connection which enables us to pass from one 
 idea to another, and to recall the most distant. Therefore we 
 remember an idea that we had some time since only because 
 we recall, more or less rapidly, the intermediary ideas. 
 
 21. In the case of the second sensation our statue experiences, 
 it has not to make any selection: it can remember but the first 
 sensation. It will merely act more or less vigorously, according 
 as it is inclined thereto by the intensity of the pleasure or the 
 pain. 
 
 But when there has been a succession of changes, the statue, 
 having a great number in remembrance, will be inclined to re- 
 call preferably those which can best contribute to its happiness, 
 passing rapidly over the others or dwelling on them only in spite 
 of itself. 
 
 To make this truth fully plain it is necessary to know the 
 different degrees of pain and of pleasure of which we are suscep- 
 tible, and the comparisons which may be drawn between them. 
 
 22. Pleasures and pains are of two kinds. Some pertain more 
 especially to the body: they are of the senses; others are within 
 the memory and all the faculties of the soul : these are intellectual 
 or spiritual. But this is a difference which the statue is incapable 
 of observing. 
 
 This inability preserves it from an error which we find it diffi- 
 cult to avoid, seeing that these sentiments do not differ one from 
 another as greatly as we imagine. In truth, they are all intellect- 
 ual and spiritual, since it is the soul only which is capable of 
 feeling. It may be said also that they are all likewise in a certain 
 sense sensible or corporeal, since the body is their sole occasion- 
 ing cause. It is only with reference to their relation to the facul- 
 ties of the body or those of the soul that we divide them into two 
 kinds. 
 
 23. Pleasure may diminish or increase by degrees; when it 
 diminishes, it tends to disappear, and it vanishes with the sensa- 
 tion. On the contrary, when it increases, it may attain to pain, 
 because the impression becomes too strong for the organ. Thus 
 there are two extreme points in pleasure: the weaker is that in 
 which sensation begins with the least power; it is the first step
 
 348 CONDILLAC 
 
 from nothingness to feeling; the strongest is that when the sen- 
 sation cannot augment without ceasing to be agreeable; it is the 
 condition nearest to pain. 
 
 The impression of a faint pleasure seems to become concen- 
 trated in the organ which transmits it to the soul. But when it 
 has a certain amount of intensity, it is accompanied by an emo- 
 tion which spreads throughout the whole body. This emotion is 
 a fact which our experience places beyond the shadow of a doubt. 
 
 Pain, likewise, may increase or diminish. When it increases 
 it tends to the total destruction of the animal; but, when it dimin- 
 ishes, it does not, like pleasure, tend to the privation of all sense 
 of feeling; on the contrary, the moment which puts an end to it 
 is always pleasant. 
 
 24. It is impossible to discover among these various degrees 
 a state of indifference; with the first sensation, no matter how 
 weak it may be, the statue is necessarily ill or well. But once it 
 shall have experienced successively the sharpest pains and the 
 liveliest pleasures, it will consider indifferent, or will cease to 
 regard as agreeable or disagreeable, the weaker sensations which 
 it will have compared with the stronger. 
 
 We may therefore suppose that there are for it divers degrees, 
 agreeable or disagreeable, in the modes of being, and others 
 which it regards as indifferent. 
 
 25. Whenever it is ill or less well, it recalls its past sensations, 
 compares them with its actual condition, and feels that it is 
 important that it should become once more what it was formerly. 
 Hence springs the need or knowledge of a state of well-being, 
 which it concludes that it needs to enjoy. 
 
 Therefore it knows that it has wants only because it compares 
 the pain from which it is suffering with the pleasures it has en- 
 joyed. Destroy in it the remembrance of these pleasures, and 
 the statue will be ill, without suspecting that it has any want, 
 for, in order to feel the need of anything, one must be acquainted 
 with it. Now, in the above supposititious case, the statue is not 
 acquainted with any other state of being than that in which it 
 finds itself. But once it recalls a happier state, its existing con- 
 dition at once causes it to feel the want of that state. Thus it is
 
 TREATISE ON SENSATIONS 349 
 
 that pleasure and pain will always determine the action of its 
 faculties. 
 
 26. The want experienced by the statue may be caused by a 
 genuine pain, by a disagreeable sensation, by a sensation less 
 agreeable than those which have preceded it, or, finally, by a 
 state of languor, in which it is reduced to one of those states of 
 being which it has become accustomed to consider indifferent. 
 
 If its need is caused by an odour which gives it lively pain, the 
 need appropriates the power of feeling almost wholly, and leaves 
 only strength enough to the memory to remind the statue that it 
 has not always been so ill. Then it becomes incapable of compar- 
 ing the various states of being through which it has passed ; it is 
 unable to judge which is the most agreeable. All that it desires 
 is to emerge from that condition in order to enjoy another, no 
 matter what it may be; and if it were acquainted with a means 
 of escaping from its suffering, it would apply all its faculties to 
 the making use of that means. It is thus that in serious sickness 
 we cease to desire the pleasures we formerly ardently sought, and 
 think only of regaining our health. 
 
 When it is a less agreeable sensation which gives rise to the 
 want, there are two cases to be distinguished: either the plea- 
 sures with which the statue compares that sensation have been 
 lively, and accompanied by the strongest emotions, or else they 
 have been less powerful and have scarcely moved it. 
 
 In the former case, the past happiness is recalled with the 
 greater force the more it differs from the immediate sensation. 
 The emotion which accompanied it is partly reproduced, and 
 drawing to itself almost the totality of the power of feeling, does 
 not permit the agreeable feelings which have preceded or fol- 
 lowed it to be noticed. The statue, then, experiencing no dis- 
 traction, compares more accurately that happiness with its pre- 
 sent state; it judges more truly how greatly that state differs 
 from the former, and, as it endeavours to depict it to itself in 
 the most vivid manner, the privation of that happiness gives rise 
 to a more insistent need, and the possession of it becomes a 
 much more necessary welfare. 
 
 In the second case, on the contrary, that state of happiness
 
 350 CONDILLAC 
 
 is recalled with much less intensity: other pleasures divide the 
 attention; the advantages it offers are less felt; it reproduces but 
 little emotion or none at all. Therefore the statue is less inter- 
 ested in its return, and does not apply its faculties to it so ear- 
 nestly. 
 
 Finally, if the need springs from one of those sensations which 
 it has got into the habit of considering indifferent, it lives at first 
 without feeling either pain or pleasure. But this state, compared 
 with the happy situations in which it has found itself, soon 
 becomes disagreeable to the statue, and the pain it then expe- 
 riences is what we term ennui. Meanwhile the ennui lasts, in- 
 reases, becomes unbearable, and determines powerfully all the 
 'acuities towards that happiness of which the statue feels the 
 loss. 
 
 This ennui may be as crushing as pain, in which case the statue 
 has no other thought than to get rid of it, and turns, without 
 selecting, to all the conditions of being which are fitted to cause 
 it to disappear. But if we diminish the burden of ennui the 
 condition of the statue will be less unhappy, it will feel less im- 
 periously the need of being rid of it, it will be in a condition to 
 devote its attention to all the agreeable sentiments of which it 
 has any recollection, and it is the pleasure, the remembrance of 
 which it recalls in the liveliest manner, which will draw all the 
 faculties to itself. 
 
 27. There are then two principles which determine the degree 
 of action of its faculties : on the one hand, the lively remembrance 
 of a well-being it has lost ; on the other, the small amount of plea- 
 sure in the sensation actually felt, or else the pain by which it is 
 accompanied. 
 
 When these two principles unite, the statue makes a greater 
 effort to recall what it has ceased to be, and it feels less what it 
 actually is. For its power of feeling being necessarily limited, 
 memory cannot attract a part of this power to itself without 
 leaving less to the sense of smell. Even if the action of this faculty 
 should be so strong as to appropriate to itself the whole power 
 of feeling, the statue will not observe any more the impression 
 made upon its organ, and it will recall its former condition in so
 
 TREATISE ON SENSATIONS 35 r 
 
 lively a manner that it will believe itylf to bf 
 dition. 
 
 28. But if its actual condition is the happiest it knows, then 
 pleasure induces it to enjoy it by preference. There no longer 
 exists any cause capable of inducing the mind to act strongly 
 enough to overbear the sense of smell to the extent of destroying 
 the feeling in it. Pleasure, on the contrary, concentrates at least 
 the greater part of the attention or of the capacity for feeling 
 upon the present sensation; and if the statue even yet recalls 
 what it has been, it is because the comparison with its present 
 state causes it to enjoy its happiness still more. 
 
 29. Here then are two of the effects of memory: the one is a 
 sensation which is recalled as strongly as if it were acting upon 
 the organ itself; the other is a sensation of which naught remains 
 but a faint recollection. 
 
 There are thus in the action of this faculty of memory two 
 degrees which we can establish: the weaker is that in which it 
 causes pleasure in the past to but a slight extent ; the other that 
 in which it causes enjoyment of that past just as if the past 
 were the present. 
 
 It is called memory when it recalls things as past only, and it 
 is called imagination when it recalls them so strongly that they 
 appear to be present. Imagination, therefore, is found in our 
 statue, as well as memory, and these two faculties differ in decree 
 only. Memory is the beginning of an imagination which is yet 
 still weak; imagination is memory itself, which has attained the 
 fullest power of which it is susceptible. 
 
 Having distinguished two forms of attention in the statue, 
 the one acting through the sense of smell, the other through the 
 memory, we may now note a third, which acts through the im- 
 agination, and the peculiarity of which is to stay the impressions 
 of the senses in order to substitute in their place a feeling inde- 
 pendent of external objects. 
 
 30. Nevertheless when the statue imagines a sensation which 
 it no longer is experiencing, and when it recalls it in as lively a 
 manner as if it were still experiencing it, it is not aware that there 
 exists in itself a cause which produces the same effect as would
 
 352 CONDILLAC 
 
 be produced by an odoriferous body acting upon its organ of 
 smell. It cannot therefore distinguish, as we do, between im- 
 agination and feeling. 
 
 31. But we may presume that the imagination of the statue 
 will be more active than is our own. Its power of feeling is wholly 
 concentrated on a single kind of sensation; the whole force of 
 its faculties is devoted solely to odours; nothing can distract 
 it. But we are divided between a multitude of sensations and 
 ideas, which are constantly assailing us, and, devoting to our 
 imagination but a part of our powers, we imagine but feebly. 
 Besides, our senses, continually on their guard against our im- 
 agination, warn us constantly of the objects we seek to imagine, 
 while, on the contrary, the imagination of our statue is entirely 
 free to act. Therefore it recalls trustingly an odour which it has 
 enjoyed, and it does actually enjoy it, just as if its sense of smell 
 were affected by it. Finally the ease with which we can put aside 
 
 / I things offensive to us, and seek those the enjoyment of which ll 
 I we prize, further contributes to render our imagination lazy. " 
 I But since our statue can escape from a disagreeable feeling 
 only by imagining strongly a condition of being in which it takes 
 pleasure, its imagination is more exercised by it, and must pro- 
 duce effects out of the power of our own to attain. 
 
 32. Yet there is one case in which the action of the statue's 
 imagination is wholly suspended, and even also that of memory. 
 It is when a sensation is so vivid as to fulfil completely the power 
 
 1 of feeling. Then the statue iswhollyDassiye. Pleasure becomes 
 for it a species of intoxication, in which there is scarcely any 
 enjoyment, and pain a crushing in which it scarcely suffers. 
 
 33. But the moment the sensation loses some degrees of its 
 intensity, forthwith the faculties of the soul become active once 
 more, and need becomes once again the cause which determines 
 their action. 
 
 34. The modifications which must give the greatest pleasure 
 to the statue are not always those it has most recently expe- 
 rienced. They may occur in the beginning or in the middle of 
 the chain of its knowledge, or at the end. Imagination, there- 
 fore, is frequently compelled to pass rapidly over intermediate
 
 TREATISE ON SENSATIONS 353 
 
 ideas. It brings nearer the more distant, changes the order they 
 were in in the memory, and out of them forms an entirely new 
 chain. 
 
 The connection of ideas does not then follow the same order 
 in its faculties. The more that order it derives from the imagi- 
 nation becomes familiar to the statue, the less will it preserve 
 that order which memory has furnished it with. Thus ideas are 
 connected in innumerable different ways, and often the statue 
 will recall less the order in which it experienced its sensations 
 than the order in which it has imagined them to be. 
 
 35. All these series, however, are formed only through the 
 comparisons which have been made between each preceding 
 and each succeeding link in the chain, and through the conclu- 
 sions which have been drawn concerning their relation to each 
 other. This connection becomes stronger in proportion as the 
 use of the faculties strengthens the habits of recollection and 
 imagination; and this is the reason why we possess the surpris- 
 ing advantage of recognizing sensations we have already expe- 
 rienced. 
 
 36. For, indeed, if we cause our statue to smell an odour with 
 which it is familiar, it is a state of being which it has compared, 
 which it has drawn a conclusion, from, and which it has linked 
 to some of the parts of the series which its memory is in the habit 
 of reviewing. That is why it concludes that the state in which 
 it finds itself is the same as that in which it formerly found itself. 
 But an odour which it has not yet smelled does not come within 
 this case, and therefore must strike it as quite new. 
 
 37. It is needless to point out that when it recognizes a state 
 of being it does so without being able to account for the fact. 
 The cause of a phenomenon of this sort is so difficult to make 
 out that all men who do not know how to observe and analyze 
 what is going on within them, are unable to perceive it. 
 
 38. But when the statue goes on a long time without thinking 
 of a state of being, what becomes, during that period, of the idea 
 it has formed of that state? When, later, that idea is recalled 
 
 
 
 by the memory, whence does it spring ? Is it in the soul or in the 
 body that it has been preserved ? In neither.
 
 354 CONDILLAC 
 
 It is not in the soul, since an alteration in the brain is sufficient 
 to destroy the power of recalling the idea. 
 
 It is not in the body. The physical cause alone could be pre- 
 served there, and for that it would be necessary to suppose that 
 the brain would remain precisely in the condition into which it 
 was brought by the sensation which the statue remembers. But 
 how can that supposition be maintained in view of the con- 
 tinual movements of the mind? How can it be maintained, 
 especially when one considers the innumerable ideas stored in 
 the memory? The phenomenon may be explained in a much 
 simpler way. 
 
 I experience a given sensation when there occurs in one of my 
 organs a movement which is transmitted to the brain. If the 
 same movement originates in the brain and is transmitted to the 
 organ, I believe I experience a sensation which I do not really 
 experience: it is an illusion. But if the movement begins and 
 -ends in the brain, I remember the sensation I have experiencecfr 
 
 When the statue recalls an idea, then, it is not because the 
 idea has been preserved in the body or in the soul; it is because 
 the movement, which is the physical and occasioning cause of 
 it, is reproduced in the brain. This, however, is not the place to 
 venture on conjectures concerning the mechanism of memory. 
 We preserve the remembrance of our sensations, we recall them, 
 although we have been a long time without thinking of them. 
 To bring this about it is sufficient that they should have strongly 
 impressed themselves upon us, or that we should have expe- 
 rienced them repeatedly. These facts authorize me to suppose 
 that our statue, organized as we are, is, like ourselves, able to 
 remember. 
 
 39. We conclude then that it has contracted several habits: 
 the habit of bestowing its attention; the habit of remember- 
 ing; a third habit of comparing; a fourth of judging; a fifth of 
 imagining; and finally one of recognizing. 
 
 40. The same causes which have produced habits are alone 
 capable of maintaining them. I mean that habits will become 
 lost unless they are renewed by actions reiterated from time to 
 time. In that case our statue will re.call neither the comparisons
 
 TREATISE ON SENSATIONS 355 
 
 between states of being which it has made, nor the conclusions 
 it has drawn from them, and it will experience a state of being 
 for the third or fourth time without being able to recognize it. 
 
 41. But we may ourselves help to maintain the practice of its 
 memory and of all its faculties. It is sufficient to induce it, by 
 different degrees of pleasure or of pain, to cling to its state of 
 being or to escape from it. The skill with which we make use of 
 its sensations will enable us to fortify and extend more and more 
 its habits. There is even ground for conjecturing that the statue 
 will distinguish, in a succession of odours, differences which we 
 fail to note. Compelled to apply all its faculties to a single sort 
 of sensation, may not the statue exhibit more discernment therein 
 than we do? 
 
 42. Yet the relations which its judgment can discover are 
 very few in number. It merely is aware that one state of being 
 is the same as a state in which it has already been, or else that it 
 is different; that the one is agreeable, the other disagreeable, 
 and both in a greater or less degree. 
 
 But will it distinguish between several odours smelled to- 
 gether? That is a power of discernment which we ourselves 
 acquire only by long practice, and even then within very narrow 
 limits, for there is no one who can recognize by the sense of 
 smell all the components of a sachet. Now it .seems to me that 
 any mingling of odours must be a sachet to our statue. 
 
 It is the knowledge of odoriferous bodies, as we shall see later, 
 which has taught us to recognize two odours within a third. 
 After having smelled in turn a rose and a jonquil, we smelled 
 them together, and thus learned that the sensation caused in 
 us by these two flowers together is composed of two other sen- 
 sations. But if the odours be multiplied we can distinguish 
 those only which are strongest, and even then we shall not dis- 
 tinguish these if the mingling has been made so skilfully that 
 no one odour shall prevail over the others. In such a case they 
 appear to pass one into another,' like colours ground up to- 
 gether; they unite and mingle so thoroughly that not one of them 
 remains what it originally was, and of many odours one alone 
 remains.
 
 356 CONDILLAC 
 
 So if our statue, at the first moment of its existence, smells 
 two odours, it will not conclude that it is at one and the same 
 time in two states of being. But let us suppose that having 
 learned to know them separately, it smells them together: will 
 it recognize them ? That does not appear probable to me. For, 
 unaware that they come from two different bodies, nothing can 
 lead it to suspect that the sensation it experiences is the sum of 
 two other sensations. Indeed, if neither prevail, it would be the 
 same with us, and if one of the two is fainter, it will merely alter 
 the stronger and they will together seem to be a simple state of 
 being. To convince ourselves of this we need only smell odours 
 which we are not accustomed to refer to separate bodies; I am 
 persuaded that we would not venture to affirm whether they are 
 one odour or several odours. And this is precisely the case of the 
 statue. 
 
 Therefore the statue acquires discernment only through the 
 attention it gives at one and the same time to a state of being 
 which it is actually experiencing and to another state which it 
 has previously experienced. Thus its judgments do not bear 
 upon two odours smelled at one and the same time, but upon 
 successive sensations. 
 
 CHAPTER III. OF THE DESIRES, THE PASSIONS, 
 LOVE, HATE, HOPE, FEAR AND WILL IN A 
 MAN LIMITED TO THE SENSE OF SMELL 
 
 1. We have just seen the character of the various kinds of 
 wants, and that they are the causes of the degrees of intensity 
 with which the faculties of the soul attach themselves to a state 
 of well-being, the enjoyment of which becomes a necessity. Now 
 desire is nothing else than the action of these faculties, when 
 these are directed towards the thing of which we feel the need. 
 
 2. Therefore every desire presupposes that the statue conceives 
 of a condition better than the one wherein it finds itself at the 
 time, and that it compares the difference between two states of 
 being succeeding each other. If they differ but little, its suffering 
 is less, in consequence of the deprivation of the mode of being
 
 TREATISE ON SENSATIONS 357 
 
 that it desires; and I give the name of discomfort or slight dis- 
 content, to the feeling it experiences. In such a case both the 
 action of its faculties is less energetic and its desires are less 
 strong. On the contrary, it suffers more if the difference be great, 
 and I give the name of anxiety, or even of torment, to the im- 
 pression it then experiences. Therefore the difference between 
 these two states is the measure of the desire, and it is sufficient 
 to remember by how much the action of the faculties gains or 
 loses in intensity in order to know all the degrees of desires. 
 
 3. For instance, they are never so violent as when the facul- 
 ties of the statue tend to a state of well-being the loss of which 
 causes an anxiety the greater in proportion to the difference of 
 that wished-for state from the existing state. In such cases, 
 nothing can distract the statue's attention from that condition: 
 it recalls it, it imagines it; all its faculties are concentrated upon 
 it. Consequently the more it desires it, the more it accustoms 
 itself to desire. In a word, it feels for it what we call a passion, 
 that is, a desire which prevents our feeling any other, or at least 
 is the most powerful one. 
 
 4. This passion persists so long as the state which is the object 
 of it continues to appear the most agreeable, and so long as the 
 absence of that state is accompanied by the same anxieties. BuK 
 it is replaced by another passion, if the statue has occasion to 
 become accustomed to another condition to which it will give 
 the preference. 
 
 5. From the moment that enjoyment, suffering, need, desire, 
 passion exist in the statue, love and hate exist likewise. For the 
 statue loves a pleasant odour, which it enjoys or desires. It hates 
 
 a disagreeable odour, which causes it to suffer; finally, it likes / 
 less a less agreeable odour, which it would fain exchange for^ 
 another. In proof of this, it is sufficient to note that to love is 
 always synonymous with to enjoy or to desire, and that to hate 
 is similarly synonymous with suffering from discomfort, from 
 discontent, in the presence of some object. 
 
 6. As there may be several gradations in the amount of anxiety 
 caused by the loss of a pleasant object, and in the discontent 
 caused by the sight of an odious one, so may similar gradations
 
 358 CONDILLAC 
 
 be noted in love and in hate. Indeed we even have words to 
 denote them: such as taste, inclination, tendency, aloofness, 
 repugnance, -disgust. Although these words cannot be substi- 
 tuted for the words love, hate, none the less the feelings they 
 express are but the beginnings of these passions ; they differ from 
 these merely in being weaker. 
 
 7. For the rest, the love of which our statue is capable, is but 
 love of self, or that which bears the name of self-love. For, in 
 truth, it loves but itself, seeing that the things it loves are but 
 its own states of being. 
 
 8. Hope and fear spring from the same principle as love and 
 hate. 
 
 Our statue, being in the habit of experiencing agreeable or 
 disagreeable sensations, is led to conclude that it can experience 
 further sensations of the same sort. If this conclusion combines 
 with a sensation which pleases, it produces hope; and if it 
 combines with a sensation that displeases, it causes fear. For, 
 in fact, to hope is to flatter one's self that one shall possess a 
 certain good; to fear, is to be threatened by an evil. It may be 
 noted that hope and fear contribute to increase desire. It is from 
 the conflict of these two feelings that the most violent passions 
 arise. 
 
 9. The remembrance that it has satisfied some of its desires 
 causes our statue to hope all the more to be able to satisfy other 
 desires, that, unaware of the obstacles which stand in the way, 
 it does not see why what it desires should not be within its power, 
 like what it has desired on other occasions. It is true that the 
 statue cannot make sure of this, but, on the other hand, it has 
 no proof of the contrary. If it more particularly remembers that 
 the same desire which it feels has formerly been followed by 
 enjoyment, it will believe itself capable of realizing it in propor- 
 tion as its want of it becomes greater. Thus two causes will con- 
 tribute to inspire it with confidence: the knowledge that it has 
 satisfied such a desire before, and its interest in satisfying it 
 once again. Henceforth the statue will not be satisfied with de- 
 siring; it will will; for by will is meant an absolute desire, such 
 that we consider that a thing we desire is in our power.
 
 CONDILLAC 359 
 
 CHAPTER VI. OF THE EGO, OR PERSONALITY OF 
 A MAN LIMITED TO THE SENSE OF SMELL 
 
 1. Our statue being capable of remembering, it is no sooner 
 one odour than it remembers that it has been another. That is its 
 personality, for if it could say /, it would say it at every instant 
 of its own duration, and each time its / would comprise all the 
 moments it remembered. 
 
 2. True, it would not say it at the first odour. What is meant 
 by that term seems to me to suit only a being which notes in 
 the present moment, that it is no longer what it has been. So 
 long as it does not change, it exists without thought of itself; but 
 as soon as it changes, it concludes that it is the selfsame which 
 was formerly in such another state, and it says 7. 
 
 This observation confirms the fact that in the first instant of 
 its existence the statue cannot form desires, for before being 
 able to say / wish, one must have said /. 
 
 3. The odours which the statue does not remember do not 
 therefore enter into the notion it has of its own person. Being as 
 foreign to its Ego as are colours and sounds, of which it has no 
 knowledge, they are, in respect of the statue, as if the statue had 
 never smelled them. Its Ego is but the sum of the sensations it 
 experiences and of those which memory recalls to it. In a word, 
 it is at once the consciousness of what it is and the remembrance 
 of what it has been. 
 
 CHAPTER VII. CONCLUSIONS FROM THE PRE- 
 CEDING CHAPTERS 
 
 i. Having proved that the statue is capable of being attentive, 
 of remembering, of comparing, of judging, of discerning, of 
 imagining; that it possesses abstract notions, notions of number 
 and duration; that it is acquainted with general and particular 
 truths; that desires are formed by it, that it has the power of 
 passions, loves, hates, wills; and finally that it contracts habits, 
 we must conclude that the mind is endowed with as many facul-
 
 
 360 TREATISE ON SENSATIONS 
 
 ties when it has but a single organ as when it has five. We shall 
 see that the faculties which appear to be peculiar to us are no- 
 thing else than the same faculties which, applied to a greater 
 number of objects, develop more fully. 
 
 2. If we consider that to remember, compare, judge, discern, 
 imagine, be astonished, have abstract notions, have notions of 
 duration and number, know general and particular truths, are 
 but different modes of attention; that to have passions, to love, 
 to hate, to hope, to fear and to will are but different modes of 
 desire, and that, finally, attention and desire are in their essence 
 but sensation, we shall conclude that sensation calls out all the 
 faculties of the soul. 
 
 3. Lastly, if we consider that there are no absolutely indiffer- 
 ent sensations, we shall further conclude that the different degrees 
 of pleasure and of pain constitute the law according to which 
 the germ of all that we are has developed in order to produce all 
 our faculties. 
 
 This principle may be called want, astonishment, or otherwise, 
 but it remains ever the same, for we are always moved by plea- 
 sure or by pain in whatever we are led to do by need or astonish- 
 ment. 
 
 The fact is that our earliest notions are pain or pleasure only. 
 Many others soon follow these, and give rise to comparisons, 
 whence spring our earliest needs and our earliest desires. Our 
 researches, undertaken for the purpose of satisfying these needs 
 and desires, cause us to acquire additional notions which in their 
 turn produce new desires. The surprise which makes us feel in- 
 tensely any extraordinary thing happening to us, increases from 
 time to time the activity of our faculties^ and there is formed a 
 chain the links of which are alternately notions and desires, and 
 it is sufficient to follow up this chain to discover the progress of 
 the enlightening of man. 
 
 4. Nearly all that I have said about the faculties of the soul, 
 while treating of the sense of smell, I might have said if I had 
 taken any other sense ; it is easy to apply all to each of the senses. 
 I have now only to examine what is peculiar to each of them.
 
 THOMAS REID 
 
 (1710-1796) 
 
 ESSAYS ON THE INTELLECTUAL POWERS 
 
 OF MAN* 
 
 ESSAY II. OF THE POWERS WE HAVE BY 
 MEANS OF OUR EXTERNAL SENSES 
 
 CHAPTER V. OF PERCEPTION 
 
 IN speaking of the impressions made on our organs in percep- 
 tion, we build upon facts borrowed from anatomy and physi- 
 ology, for which we have the testimony of our senses. But, being 
 now to speak of perception itself, which is solely an act of the 
 mind, we must appeal to another authority. The operations of 
 our minds are known, not by sense, but by consciousness, the 
 authority of which is as certain and as irresistible as that of 
 sense. 
 
 In order, however, to our having a distinct notion of any of 
 the operations of our own minds, it is not enough that we be 
 conscious of them; for all men have this consciousness. It is 
 farther necessary that we attend to them while they are ex- 
 erted, and reflect upon them with care, while they are recent 
 and fresh in our memory. It is necessary that, by employing our- 
 selves frequently in this way, we get the habit of this attention 
 and reflection; and, therefore, for the proof of facts which I shall 
 have occasion to mention upon this subject, I can only appeal 
 to the reader's own thoughts, whether such facts are not agree- 
 able to what he is conscious of in his own mind. 
 
 If, therefore, we attend to that act of our mind which we call 
 the perception of an external object of sense, we shall find in it 
 these three things : First, Some conception or notion of the 
 
 * Edinburgh, 1785.
 
 362 THOMAS REID 
 
 object perceived; Secondly, A strong and irresistible conviction 
 and belief of its present existence; and, Thirdly, That this con- 
 viction and belief are immediate, and not the effect of reason- 
 ing. 
 
 First, It is impossible to perceive an object without having 
 some notion or conception of that which we perceive. We may, 
 indeed, conceive an object which we do not perceive; but, when 
 we perceive the object, we must have some conception of it at 
 the same time; and we have commonly a more clear and steady 
 notion of the object while we perceive it, than we have from 
 memory or imagination when it is not perceived. Yet, even in 
 perception, the notion which our senses give of the object may 
 be more or less clear, more or less distinct, in all possible degrees. 
 
 Thus we see more distinctly an object at a small than at a 
 great distance. An object at a great distance is seen more dis- 
 tinctly in a clear than in a foggy day. An object seen indis- 
 tinctly with the naked eye, on account of its smallness, may be 
 seen distinctly with a microscope. The objects in this room will 
 be seen by a person in the room less and less distinctly as the 
 light of the day fails; they pass through all the various degrees 
 of distinctness according to the degrees of the light, and, at 
 last, in total darkness they are not seen at all. What has been 
 said of the objects of sight is so easily applied to the objects of 
 the other senses, that the application may be left to the reader. 
 
 In a matter so obvious to every person capable of reflection, 
 it is necessary only farther to observe, that the notion which we 
 get of an object, merely by our external sense, ought not to be 
 confounded with that more scientific notion which a man, come 
 to the years of understanding, may have of the same object, by 
 attending to its various attributes, or to its various parts, and 
 their relation to each other, and to the whole. Thus, the notion 
 which a child has of a jack for roasting meat, will be acknow- 
 ledged to be very different from that of a man who understands 
 its construction, and perceives the relation of the parts to one 
 another, and to the whole. The child sees the jack and every 
 part of it as well as the man. The child, therefore, has all the 
 notion of it which sight gives; whatever there is more in the
 
 THE INTELLECTUAL POWERS OF MAN 363 
 
 notion which the man forms of it, must be derived from other 
 powers of the mind, which may afterwards be explained. This 
 observation is made here only that we may not confound the 
 operations of different powers of the mind, which by being 
 always conjoined after we grow up to understanding, are apt to 
 pass for one and the same. 
 
 Secondly, In perception we not only have a notion more or 
 less distinct of the object perceived, but also an irresistible con- 
 viction and belief of its existence. This is always the case when 
 we are certain that we perceive it. There may be a perception 
 so faint and indistinct as to leave us in doubt whether we per- 
 ceive the object or not. Thus, when a star begins to twinkle as 
 the light of the sun withdraws, one may, for a short time, think 
 he sees it without being certain, until the perception acquire 
 some strength and steadiness. When a ship just begins to appear 
 in the utmost verge of the horizon, we may at first be dubious 
 whether we perceive it or not ; but when the perception is in any 
 degree clear and steady, there remains no doubt of its reality ; 
 and when the reality of the perception is ascertained, the exist- 
 ence of the object perceived can no longer be doubted. 
 
 By the laws of all nations, in the most solemn judicial trials, 
 wherein men's fortunes and lives are at stake, the sentence 
 passes according to the testimony of eye or ear witnesses of 
 good credit. An upright judge will give a fair hearing to every 
 objection that can be made to the integrity of a witness, and 
 allow it to be possible that he may be corrupted; but no judge 
 will ever suppose that witnesses may be imposed upon by trust- 
 ing to their eyes and ears. And if a sceptical counsel should 
 plead against the testimony of the witnesses, that they had no 
 other evidence for what they declared but the testimony of 
 their eyes and ears, and that we ought not to put so much 
 faith in our senses as to deprive men of life or fortune upon their 
 testimony, surely no upright judge would admit a plea of this 
 kind. I believe no counsel, however sceptical, ever dared to 
 offer such an argument; and, if it was offered, it would be 
 rejected with disdain. 
 
 Can any stronger proof be given that it is the universal judg-
 
 364 THOMAS REID 
 
 ment of mankind that the evidence of sense is a kind of evi- 
 dence which we may securely rest upon in the most momentous 
 concerns of mankind ; that it is a kind of evidence against which 
 we ought not to admit any reasoning; and, therefore that to 
 reason either for or against it is an insult to common sense? 
 
 The whole conduct of mankind in the daily occurrences of 
 life, as well as the solemn procedure of judicatories in the trial 
 of causes civil and criminal, demonstrates this. I know only of 
 two exceptions that may be offered against this being the uni- 
 versal belief of mankind. 
 
 The first exception is that of some lunatics who have been 
 persuaded of things that seem to contradict the clear testimony 
 of their senses. It is said there have been lunatics and hypo- 
 chondriacal persons, who seriously believed themselves to be 
 made of glass; and, in consequence of this, lived in continual 
 terror of having their brittle frame shivered into pieces. 
 
 All I have to say to this is, that our minds, in our present 
 state, are, as well as our bodies, liable to strange disorders; and, 
 as we do not judge of the natural constitution of the body from 
 the disorders or diseases to which it is subject from accidents, 
 so neither ought we to judge of the natural powers of the mind 
 from its disorders, but from its sound state. It is natural to 
 man, and common to the species, to have two hands and two 
 feet; yet I have seen a man, and a very ingenious one, who was 
 born without either hands or feet. It is natural to man to have 
 faculties superior to those of brutes; yet we see some individuals 
 whose faculties are not equal to those of many brutes; and the 
 wisest man may, by various accidents, be reduced to this state. 
 General rules that regard those whose intellects are sound are 
 not overthrown by instances of men whose intellects are hurt 
 by any constitutional or accidental disorder. 
 
 The other exception that may be made to the principle we 
 have laid down is that of some philosophers who have main- 
 tained that the testimony of sense is fallacious, and therefore 
 ought never to be trusted. Perhaps it might be a sufficient an- 
 swer to this to say, that there is nothing so absurd which some 
 philosophers have not maintained. It is one thing to profess a
 
 THE INTELLECTUAL POWERS OF MAN 365 
 
 doctrine of this kind, another seriously to believe it, and to be 
 governed by it in the conduct of life. It is evident that a man 
 who did not believe his senses could not keep out of harm's way 
 an hour of his life; yet, in all the history of philosophy, we never 
 read of any sceptic that ever stepped into fire or water be- 
 cause he did not believe his senses, or that shewed in the con- 
 duct of life less trust in his senses than other men have. This 
 gives us just ground to apprehend that philosophy was never 
 able to conquer that natural belief which men have in their 
 senses; and that all their subtile reasonings against this belief 
 were never able to persuade themselves. 
 
 It appears, therefore, that the clear and distinct testimony 
 of our senses carries irresistible conviction along with it to every 
 man in his -right judgment. 
 
 I observed, Thirdly, That this conviction is not only irresisti- 
 ble, but it is immediate ; that is, it is not by a train of reasoning 
 and argumentation that we come to be convinced of the exist- 
 ence of what we perceive; we ask no argument for the exist- 
 ence of the object, but that we perceive it; perception com- 
 mands our belief upon its own authority, and disdains to rest 
 its authority upon any reasoning whatsoever. 
 
 The conviction of a truth may be irresistible, and yet not 
 immediate. Thus, my conviction that the three angles of every 
 plain triangle are equal to two right angles, is irresistible, but it 
 is not immediate; I am convinced of it by demonstrative rea- 
 soning. There are other truths in mathematics of which we 
 have not only an irresistible but an immediate conviction. 
 Such are the axioms. Our belief of the axioms in mathematics 
 is not grounded upon argument arguments are grounded 
 upon them; but their evidence is discerned immediately by the 
 human understanding. 
 
 It is, no doubt, one thing to have an immediate conviction of 
 a self-evident axiom ; it is another thing to have an immediate 
 conviction of the existence of what we see; but the conviction 
 is equally immediate and equally irresistible in both cases. No 
 man thinks of seeking a reason to believe what he sees; and, 
 before we are capable of reasoning, we put no less confidence in
 
 366 THOMAS REID 
 
 our senses than after. The rudest savage is as fully convinced 
 of what he sees, and hears, and feels, as the most expert logi- 
 cian. The constitution of our understanding determines us to 
 hold the truth of a mathematical axiom as a first principle, from 
 which other truths may be deduced, but it is deduced from none ; 
 and the constitution of our power of perception determines us 
 to hold the existence of what we distinctly perceive as a first 
 principle, from which other truths may be deduced; but it is 
 deduced from none. What has been said of the irresistible and 
 immediate belief of the existence of objects distinctly per- 
 ceived, I mean only to affirm with regard to persons so far ad- 
 vanced in understanding as to distinguish objects of mere imag- 
 ination from things which have a real existence. Every man 
 knows that he may have a notion of Don Quixote, or of Gara- 
 gantua, without any belief that such persons ever existed; and 
 that of Julius Caesar and Oliver Cromwell, he has not only a 
 notion, but a belief that they did really exist. But whether child- 
 ren, from the time that they begin to use their senses, make a 
 distinction between things which are only conceived or imag- 
 ined, and things which really exist, may be doubted. Until we 
 are able to make this distinction, we cannot properly be said to 
 believe or to disbelieve the existence of anything. The belief of 
 the existence of anything seems to suppose a notion of existence 
 a notion too abstract, perhaps, to enter into the mind of an 
 infant. I speak of the power of perception in those that are 
 adult and of a sound mind, who believe that there are some 
 things which do really exist; and that there are many things 
 conceived by themselves, and by others, which have no exist- 
 ence. That such persons do invariably ascribe existence to 
 everything which they distinctly perceive, without seeking rea- 
 sons or arguments for doing so, is perfectly evident from the 
 whole tenor of human life. 
 
 The account I have given of our perception of external 
 objects, is intended as a faithful delineation of what every 
 man, come to years of understanding, and capable of giving 
 attention to what passes in his own mind, may feel in himself. 
 In what manner the notion of external objects, and the imme-
 
 THE INTELLECTUAL POWERS OF MAN 367 
 
 diate belief of their existence, is produced by means of our 
 senses, I am not able to shew, and I do not pretend to shew. If 
 the power of perceiving external objects in certain circum- 
 stances, be a part of the original constitution of the human 
 mind, all attempts to account for it will be vain. No other 
 account can be given of the constitution of things, but the will 
 of Him that made them. As we can give no reason why matter 
 is extended and inert, why the mind thinks and is conscious of 
 its thoughts, but the will of Him who made both; so I suspect 
 we can give no other reason why, in certain circumstances, we 
 perceive external objects, and in others do not. 
 
 The Supreme Being intended that we should have such 
 knowledge of the material objects that surround us, as is neces- 
 sary in order to our supplying the wants of nature, and avoiding 
 the dangers to which we are constantly exposed; and he has 
 admirably fitted our powers of perception to this purpose. If 
 the intelligence we have of external objects were to be got by 
 reasoning only, the greatest part of men would be destitute of 
 it; for the greatest part of men hardly ever learn to reason; and 
 in infancy and childhood no man can reason : Therefore, as this 
 intelligence of the objects that surround us, and from which we 
 may receive so much benefit or harm, is equally necessary to 
 children and to men, to the ignorant and to the learned, God in 
 his wisdom conveys it to us in a way that puts all upon a level. 
 The information of the senses is as perfect, and gives as full 
 conviction to the most ignorant as to the most learned. 
 
 CHAPTER XV L OF SENSATION 
 
 HAVING finished what I intend, with regard to that act of 
 mind which we call the preception of an external object, I pro- 
 ceed to consider another, which, by our constitution, is con- 
 joined with perception, and not with perception only, but with 
 many other acts of our minds; and that is sensation. 
 
 Almost all our perceptions have corresponding sensations 
 which constantly accompany them, and, on that account, are 
 very apt to be confounded with them. Neither ought we to
 
 3 68 THOMAS REID 
 
 expect that the sensation, and its corresponding perception, 
 should be distinguished in common language, because the pur- 
 poses of common life do not require it. Language is made to 
 serve the purposes of ordinary conversation; and we have no 
 reason to expect that it should make distinctions that are not of 
 common use. Hence it happens, that a quality perceived, and 
 the sensation corresponding to that perception, often go under 
 the same name. 
 
 This makes the names of most of our sensations ambiguous, 
 and this ambiguity hath very much perplexed philosophers. 
 It will be necessary to give some instances, to illustrate the 
 distinction between our sensations and the objects of percep- 
 tion. 
 
 When I smell a rose, there is in this operation both sensation 
 and perception. The agreeable odour I feel, considered by 
 itself, without relation to any external object, is merely a sensa- 
 tion. It affects the mind in a certain way; and this affection of 
 the mind may be conceived, without a thought of the rose, or 
 any other object. This sensation can be nothing else than it is 
 felt to be. Its very essence consists in being felt; and, when 
 it is not felt, it is not. There is no difference between the 
 sensation and the feeling of it they are one and the same 
 thing. It is for this reason that we before observed that, in 
 sensation, there is no object distinct from that act of the mind 
 by which it is felt and this holds true with regard to all 
 sensations. 
 
 Let us next attend to the perception which we have in smell- 
 ing a rose. Perception has always an external object; and the 
 object of my perception, in this case, is that quality in the rose 
 which I discern by the sense of smell. Observing that the agree- 
 able sensation is raised when the rose is near, and ceases when 
 it is removed, I am led, by my nature, to conclude some quality 
 to be in the rose, which is the cause of this sensation. This qual- 
 ity in the rose is the object perceived; and that act of my mind 
 by which I have the conviction and belief of this quality, is 
 what in this case I call perception. 
 
 But it is here to be observed, that the sensation I feel, and
 
 369 
 
 the quality in the rose which I perceive, are both called by the 
 same name. The smell of a rose is the name given to both: so 
 that this name hath two meanings; and the distinguishing its 
 different meanings removes all perplexity, and enables us to 
 give clear and distinct answers to questions about which 
 philosophers have held much dispute. 
 
 Thus, if it is asked, whether the smell be in the rose, or in the 
 mind that feels it, the answer is obvious: That there are two 
 different things signified by the smell of a rose; one of which is 
 in the mind, and can be in nothing but in a sentient being; the 
 other is truly and properly in the rose. The sensation which I 
 feel is in my mind. The mind is the sentient being; and, as the 
 rose is insentient, there can be no sensation, nor anything re- 
 sembling sensation in it. But this sensation in my mind is 
 occasioned by a certain quality in the rose, which is called by 
 the same name with the sensation, not on account of any simil- 
 itude, but because of their constant concomitancy. 
 
 All the names we have for smells, tastes, sounds, and for the 
 various degrees of heat and cold, have a like ambiguity; and 
 what has been said of the smell of a rose may be applied to 
 them. They signify both a sensation, and a quality perceived 
 by means of that sensation. The first is the sign, the last the 
 thing signified. As both are conjoined by nature, and as the 
 purposes of common life do not require them to be disjoined 
 in our thoughts, they are both expressed by the same name: 
 and this ambiguity is to be found in all languages, because the 
 reason of it extends to all. 
 
 The same ambiguity is found in the names of such diseases 
 as are indicated by a particular painful sensation: such as the 
 toothache, the headache. The toothache signifies a painful 
 sensation, which can only be in a sentient being; but it signifies 
 also a disorder in the body, which has no similitude to a sensa- 
 tion, but is naturally connected with it. 
 
 Pressing my hand with force against the table, I feel pain, 
 and I feel the table to be hard. The pain is a sensation of the 
 mind, and there is nothing that resembles it in the table. The 
 hardness is in the table, nor is there anything resembling it in
 
 370 THOMAS REID 
 
 the mind. Feeling is applied to both; but in a different sense; 
 being a word common to the act of sensation, and to that of 
 perceiving by the sense of touch. 
 
 I touch the table gently with my hand, and I feel it to be 
 smooth, hard, and cold. These are qualities of the table per- 
 ceived by touch ; but I perceive them by means of a sensation 
 which indicates them. This sensation not being painful, I com- 
 monly give no attention to it. It carries my thought immedi- 
 ately to the thing signified by it, and is itself forgot, as if it had 
 never been. But, by repeating it, and turning my attention to 
 it, and abstracting my thought from the thing signified by it, I 
 find it to be merely a sensation, and that it has no similitude 
 to the hardness, smoothness, or coldness of the table, which are 
 signified by it. 
 
 It is indeed difficult, at first, to disjoin th : ngs in our attention 
 which have always been conjoined, and to make that an object 
 of reflection which never was so before; but some pains and 
 practice will overcome this difficulty in those who have got the 
 habit of reflecting on the operations of their own minds. 
 
 Although the present subject leads us only to consider the 
 sensations which we have by means of our external senses, yet 
 it will serve to illustrate what has been said, and, I apprehend, 
 is of importance in itself, to observe, that many operations of 
 mind, to which we give one name, and which we always con- 
 sider as one thing, are complex in their nature, and made up of 
 several more simple ingredients ; and of these ingredients sensa- 
 tion very often makes one. Of this we shall give some instances. 
 
 The appetite of hunger includes an uneasy sensation, and a 
 desire of food. Sensation and desire are different acts of mind. 
 The last, from its nature, must have an object ; the first has no 
 object. These two ingredients may always be separated in 
 thought perhaps they sometimes are, in reality; but hunger 
 includes both. 
 
 Benevolence towards our fellow-creatures includes an agree- 
 able feeling; but it includes also a desire of the happiness of 
 others. The ancients commonly called it desire. Many mod- 
 erns choose rather to call it a feeling. Both are right: and they
 
 THE INTELLECTUAL POWERS OF MAN 371 
 
 only err who exclude either of the ingredients. Whether these 
 two ingredients are necessarily connected, is, perhaps, difficult 
 for us to determine, there being many necessary connections 
 which we do not perceive to be necessary; but we can disjoin 
 them in thought. They are different acts of the mind. 
 
 An uneasy feeling, and a desire, are, in like manner, the in- 
 gredients of malevolent affections; such as malice, envy, re- 
 venge. The passion of fear includes an uneasy sensation or 
 feeling, and an opinion of danger; and hope is made up of the 
 contrary ingredients. When we hear of a heroic action, the 
 sentiment which it raises in our mind, is made up of various 
 ingredients. There is in it an agreeable feeling, a benevolent 
 affection to the person, and a judgment or opinion of his merit. 
 
 If we thus analyse the various operations of our minds, we 
 shall find that many of them which we consider as perfectly 
 simple, because we have been accustomed to call them by one 
 name, are compounded of more simple ingredients; and that 
 sensation, or feeling, which is only a more refined kind of sensa- 
 tion, makes one ingredient, not only in the perception of 
 external objects, but in most operations of the mind. 
 
 A small degree of reflection may satisfy us that the number 
 and variety of our sensations and feelings is prodigious; for, to 
 omit all those which accompany our appetites, passions, and 
 affections, our moral sentiments and sentiments of taste, even 
 our external senses, furnish a great variety of sensations, differ- 
 ing in kind, and almost in every kind an endless variety of 
 decrees. Every variety we discern, with regard to taste, smell, 
 sovnd, colour, heat, and cold, and in the tangible qualities of 
 bodies, is indicated by a sensation corresponding to it. 
 
 The most general and the most important division of our 
 sensations and feelings, is into the agreeable, the disagreeable, 
 and the indifferent. Everything we call pleasure, happiness, or 
 enjoyment, on the one hand; and, on the other, everything we 
 call misery, pain, or uneasiness, is sensation or feeling; for no 
 man can for the present be more happy or more miserable than 
 he feels himself to be. He cannot be deceived with regard to the 
 enjoyment or suffering of the present moment.
 
 372 THOMAS REID 
 
 But I apprehend that, besides the sensations that are either 
 agreeable or disagreeable, there is still a greater number that 
 are indifferent. To these we give so little attention, that they 
 have no name, and are immediately forgot, as if they had never 
 been; and it requires attention to the operations of our minds 
 to be convinced of their existence. 
 
 For this end we may observe, that, to a good ear, every 
 human voice is distinguishable from all others. Some voices 
 are pleasant, some disagreeable; but the far greater part can 
 neither be said to be one nor the other. The same thing may be 
 said of other sounds, that no less of tastes, smells, and colours; 
 and, if we consider that our senses are in continual exercise 
 while we are awake, and some sensation attends every object 
 they present to us, and that familiar objects seldom raise any 
 emotion, pleasant or painful, we shall see reason, besides the 
 agreeable and disagreeable, to admit a third class of sensations 
 that may be called indifferent. 
 
 The sensations that are indifferent, are far from being use- 
 less. They serve as signs to distinguish things that differ; and 
 the information we have concerning things external, comes by 
 their means. Thus, if a man had no ear to receive pleasure from 
 the harmony or melody of sounds, he would still find the sense 
 of hearing of great utility. Though sounds give him neither 
 pleasure nor pain of themselves, they would give him much 
 useful information; and the like may be said of the sensations 
 we have by all the other senses. 
 
 As to the sensations and feelings that are agreeable or dis- 
 agreeable, they differ much not only in degree, but in kind and 
 in dignity. Some belong to the animal part of our nature, and 
 are common to us with the brutes; others belong to the rational 
 and moral part. The first are more properly called sensations; 
 the last, feelings. The French word sentiment is common to 
 both. 
 
 I shall conclude this chapter by observing that, as the con- 
 founding our sensations with that perception of external 
 objects which is constantly conjoined with them, has been the 
 occasion of most of the errors and false theories of philosophers
 
 THE INTELLECTUAL POWERS OF MAN 373 
 
 with regard to the senses; so the distinguishing these opera- 
 tions seems to me to be the key that leads to a right under- 
 standing of both. 
 
 Sensation, taken by itself, implies neither the conception nor 
 belief of any external'object. It supposes a sentient being, and 
 a certain manner in which that being is affected; but it sup- 
 poses no more. Perception implies an immediate conviction 
 and belief of something external something different both 
 from the mind that perceives, and from the act of perception. 
 Things so different in their nature ought to be distinguished ; 
 but, by our constitution, they are always united. Every dif- 
 ferent perception is conjoined with a sensation that is proper to 
 it. The one is the sign, the other the thing signified. They 
 coalesce in our imagination. They are signified by one name, 
 and are considered as one simple operation. The purposes of 
 life do not require them to be distinguished. 
 
 It is the philosopher alone who has occasion to dis- 
 tinguish them, when he would analyse the operation com- 
 pounded of them. But he has no suspicion that there is 
 any composition in it ; and to discover this requires a de- 
 gree of reflection which has been too little practised by 
 philosophers.
 
 THOMAS BROWN 
 
 (1778-1820) . 
 
 LECTURES ON THE PHILOSOPHY OF 
 THE HUMAN MIND* 
 
 PART II 
 
 CHAPTER V. SECTION I. THE MUSCULAR 
 SENSATIONS 
 
 IN defining sensation, when we began our inquiry into its 
 nature, to be that affection of the mind, which is immediately 
 subsequent to the affection of certain organs, induced by the 
 action of external bodies; two assumptions were made, the 
 existence of foreign changeable external bodies, as separate 
 from the mind, and the existence of organs, also separate 
 from the mind, and in relation to it truly external, like other 
 bodies, but forming a permanent part of our corporeal frame, 
 and capable of being affected, in a certain manner, by the other 
 bodies, of which the existence was assumed. As far as our 
 analytical inquiry has yet proceeded, these assumptions are 
 assumptions still. We have not been able to detect, in the sens- 
 ations considered more than in any of our internal pleasures 
 or pains, any circumstances that seem to be indicative of a 
 material world without. 
 
 Our analytical inquiry itself, however, even in attempting to 
 trace the circumstances in which the belief originates, must pro- 
 ceed on that very belief. Accordingly, in examining our senses 
 of smell, taste, and hearing, I uniformly took for granted the 
 existence of odoriferous, sapid, and vibrating bodies, and con- 
 
 * Edinburgh, 1820. Reprinted from T. Brown's A Treatise on the Philosophy 
 of the Human Mind, abridged by Levi Hedge, Cambridge, 1827, vol. i.
 
 PHILOSOPHY OF THE HUMAN MIND 375 
 
 sidered merely, whether the sensations excited by these, were, 
 of themselves, capable of communicating to us any knowledge 
 of the external and independent existence of the bodies which 
 excited them. 
 
 In the present stage of our inquiry, I must, in like manner, 
 take for granted the existence of bodies, which act, by their 
 contiguity or pressure, on our organs of touch, as the odoriferous 
 or sapid particles act on our nerves of smell and taste. All our 
 language is at present adapted to a system of external things. 
 There is no direct vocabulary of skepticism; and even the most 
 cautious and philosophic inquirer, therefore, must often be 
 obliged to express his doubt, or his dissent, in language that 
 implies affirmation. In the present case, when we attempt to 
 analyze our sensations, it is impossible to speak of the circum- 
 stances in which the infant is placed, or even to speak of the 
 infant himself, without that assumption which we have been 
 obliged to make. The real existence of an external universe, and 
 the belief of that existence, are, however, in themselves, per- 
 fectly separate and distinct; and it is not the existence of an 
 external world which we are now endeavouring to establish as 
 an object of belief. We are only endeavouring, in our analysis 
 of the sensations afforded by our different organs, to ascertain 
 in what circumstance the belief arises. There might be a world 
 of suns and planets, though there were no human being, whose 
 mind could be affected with belief of it; and even the most 
 zealous defenders of the reality of external nature must admit, 
 that, though no created thing but ourselves were in existence, 
 our mind might still have been so constituted, as to have the 
 very series of feelings, which form at present its successive 
 phenomena, and which are ascribed in no small number to the 
 action of external things. 
 
 Are the primary sensations derived from the organ oftouch, 
 then, of such a kind as to afford us that knowledge, which they 
 are supposed to give of things without? 
 
 Let us imagine a being, endowed with the sense of touch, and 
 with every other sense and faculty of our mind, but not with any 
 previous knowledge of his own corporeal frame, or of other
 
 376 THOMAS BROWN 
 
 things external, and let us suppose a small body, of any 
 shape, to be pressed, for the first time, on his open hand. What- 
 ever feeling mere touch can give, directly of itself, would of 
 course be the same in this case, as now, when our knowledge is 
 increased and complicated, from many other sources. 
 
 Let the body, thus impressed, be supposed to be a small cube, 
 of the same temperature with the hand itself, that all consider- 
 ations of heat or cold may be excluded, and the feeling produced 
 be as simple as possible. 
 
 What, then, may we suppose the consequent feeling to be? 
 
 It will, I conceive, be a simple feeling of the kind already 
 spoken of, as capable of arising from the affection of a single 
 point of our organ of touch, a feeling that varies indeed 
 with the quantity of pressure as the sensation of fragrance 
 varies with the number of the odorous particles, but involves 
 as little the notion of extension, as that notion is involved in the 
 mere fragrance of a violet or a rose. The connexion of this 
 original tactual feeling, however, with that of extension, is now 
 so indissoluble, as, indeed, it could not fail to become, in the cir- 
 cumstance in which it has uniformly arisen, that it is almost 
 impossible to conceive it as separate. We may perhaps, how- 
 ever, make a near approach to the conception of it, by using the 
 gentle gradual pressure of a small pointed body, which, in the 
 various slight feelings, excited by it, before it penetrate the 
 cuticle, or cause any considerable pain, may represent, in 
 some measure, the simple and immediate effect, which pressure 
 in any case produces, exclusively of the associate feelings 
 which it indirectly suggests. 
 
 Those who have the curiosity to try the experiment, with any 
 small bodies, not absolutely pointed, such as the head of a 
 pin, or any body of similar dimensions, will be astonished to 
 feel, how very slightly, if at all, the notion of extension, or 
 figure, is involved in the feeling, even after all the intimate asso- 
 ciations of our experience ; certainly far less than the notion of 
 longitudinal distance seems to us to be involved in the immedi- 
 ate affections of our sense of sight. 
 
 But the pressure of such a large body as the cube, which we
 
 PHILOSOPHY OF THE HUMAN MIND 377 
 
 have supposed to be pressed against our organ of touch, now 
 awakens very different feelings. We perceive, as it were imme- 
 diately, form and hardness. May not, then, the knowledge of 
 resistance and extension, and consequently the belief of the 
 essential qualities of matter, be originally communicated by the 
 affections of this organ? 
 
 The feeling of resistance, to begin with this, is, I con- 
 ceive, to be ascribed, not to our organ of touch, but to our 
 muscular frame, as forming a distinct organ of sense ; the affec- 
 tions of which, particularly as existing in combination with 
 other feelings, and modifying our judgments concerning these, 
 (as in the case of distant vision, for example,) are not less impor- 
 tant than those of our other sensitive organs. The sensations of 
 this class, are, indeed, in common circumstances, so obscure, as 
 to be scarcely heeded or remembered ; but there is probably no 
 contraction, even of a single muscle, which is not attended with 
 some faint degree of sensation, that distinguishes it from the 
 contraction of other muscles, or from other degrees of contrac- 
 tion of the same muscle. Each motion of the visible limb, 
 whether produced by one or more of the invisible muscles, is 
 accompanied with a certain feeling, that may be complex, 
 indeed, as arising from various muscles, but which is consid- 
 ered by the mind as one; and it is this particular feeling, accom- 
 panying the particular visible motion, whether the feeling 
 and the invisible parts contracted be truly simple or compound, 
 which we distinguish from every other feeling accompanying 
 every other quantity of contraction. It is as if a man, born 
 blind, were to walk, for the first time, in a flower garden. He 
 would distinguish the fragrance of one parterre from the fra- 
 grance of another, though he might be altogether ignorant 01 
 the separate odours united in each; and might even consider 
 as one simple perfume, what was, in truth, the mingled pro- 
 duct of a thousand. 
 
 Obscure as our muscular sensations are in common circum- 
 stances, there are other circumstances in which they make 
 themselves abundantly manifest. It is sufficient to refer to 
 phenomena of which every one must have been conscious in-
 
 378 THOMAS BROWN 
 
 numerable times, and which imply no disease nor lasting differ- 
 ence of state. What is the feeling of fatigue, for example, but a 
 muscular feeling? that is to say, a feeling of which our muscles 
 are as truly the organ, as our eye or ear is the organ of sight or 
 hearing. When a limb has been long exercised, without suffi- 
 cient intervals of rest, the repetition of the contraction of its 
 muscles is accompanied, not with a slight and obscure sensa- 
 tion, but with one which amounts, if it be gradually increased, 
 to severe pain, and which, before it arrives at this, has passed 
 progressively through various stages of uneasiness. Even when 
 there has been no previous fatigue, we cannot make a single 
 powerful effort at any time, without being sensible of the mus- 
 cular feeling connected with this effort. Of the pleasure which 
 attends more moderate exercise, every one must have been con- 
 scious in himself, even in his years of maturity, when he seldom 
 has recourse to it for the pleasure alone; and must remember, 
 still more, the happiness which it afforded him in other years, 
 when happiness was of less costly and laborious production 
 than at present. By that admirable provision, with which Na- 
 ture accommodates the blessings which she gives, to the wants 
 that stand in need of them, she has, in that early period, 
 when the pleasure of mental freedom, and the ambitions of 
 busy life, are necessarily excluded, made ample amends to 
 the little slave of affections, in that disposition to spontaneous 
 pleasure, which renders it almost an effort to be sad, as if exist- 
 ence itself were delight; giving him a fund of independent hap- 
 piness in the very air which she has poured around him, and the 
 ready limbs which move through it almost without his bidding. 
 In that beautiful passage, in which Goldsmith describes the 
 sounds that come in one mingled murmur from the village, who 
 does not feel the force of the happiness which is comprised in 
 the single line, that speaks of 
 
 " The playful children just let loose from school ? " l 
 
 It is not the mere freedom from the intellectual task, of which 
 
 we think; it is much more that burst of animal pleasure, which 
 
 1 Deserted Village, v. 120.
 
 PHILOSOPHY OF THE HUMAN MIND 379 
 
 is felt in every limb, when the long constraint that has repressed 
 it is removed, and the whole frame is given once more to all the 
 freedom of nature. 
 
 With the same happy provision with which she has consid- 
 ered the young of our own species, Nature has, in the other 
 animals, whose sources of general pleasure are still more limited 
 than in the child, converted their muscular frame into an organ 
 of delight. It is not in search of richer pasture, that the horse 
 gallops over his field, or the goat leaps from rock to rock; it is 
 for the luxury of the exercise itself. It is this appearance of 
 happy life which spreads a charm over every little group with 
 which Nature animates her scenery; and he who can look with- 
 out interest on the young lamb, as it frolics around the bush, 
 may gaze, indeed, on the magnificent landscape as it opens 
 before him, but it will be with an eye which looks languidly, 
 and in vain, for pleasure which it cannot find. 
 
 Our muscular frame is not merely a part of the living ma- 
 chinery of motion, but is also truly an organ of sense. When I 
 move my arm, without resistance, I am conscious. of a certain 
 feeling; when the motion is impeded by the presence of an ex- 
 ternal body, I am conscious of a different feeling, arising partly, 
 indeed, from the mere sense of touch, in the moving limb com- 
 pressed, but not consisting merely in this compression, since, 
 when the same pressure is made by a foreign force, without any 
 muscular effort on my part, my general feeling is very different. 
 It is the feeling of this resistance to our progressive effort, 
 (combined, perhaps, with the mere tactual feeling) which 
 forms what we term our feeling of solidity, or hardness; and with- 
 out it the tactual feeling would be nothing more than a sensa- 
 tion indifferent or agreeable, or disagreeable or severely pain- 
 ful, according to the force of the pressure, in the particular case; 
 in the same way as the matter of heat, acting in different de- 
 grees on this very organ of touch, and on different portions of its 
 surface at different times, produces all the intermediate sensa- 
 tions, agreeable, disagreeable, or indifferent, from the pain of 
 excessive cold, to the pain of burning; and produces them in 
 like manner, without suggesting the presence of any solid body 
 external to ourselves.
 
 38o THOMAS BROWN 
 
 Were the cue, therefore, in the case supposed, pressed for the 
 first time on me hand, it would excite a certain sensation, in- 
 deed, but not that of resistance, which always implies a muscu- 
 lar effort that is resisted, and consequently not that of hardness 
 which is a mode of resistance. It would be very different, how- 
 ever, if we fairly made the attempt to press against it; for then 
 our effort would be impeded, and the consequent feeling of 
 resistance would arise; which, as co-existing in this case, and in 
 every case of effort, with the particular sensation of touch, 
 might afterwards be suggested by it, on the simple recurrence 
 of the same sensation of touch, so as to excite the notion of 
 hardness in the body touched, without the renewal of any mus- 
 cular effort on our part, in the same manner as the angular sur- 
 faces of the cube, if we chance to turn our eye upon it, are sug- 
 gested by the mere plane of colour, which it presents to our 
 immediate vision, and which is all that our immediate vision 
 would, of itself, have made known to us. The feeling of resist- 
 ance, then, it will be admitted, and consequently of hardness, 
 and all the other modes of resistance, is a muscular, not a 
 tactual feeling. 
 
 SECTION IL SPACE PERCEPTION 
 
 The proof, that our perception of extension by touch, is not 
 an original and immediate perception of that sense, is alto- 
 gether independent of the success of any endeavour which may 
 be made, to discover the elements of the compound perception. 
 It would not be less true, that touch does not afford it, though 
 we should be incapable of pointing out any source, from which 
 it can be supposed to be derived. 
 
 To those who are wholly unacquainted with the theory of 
 vision, nothing certainly can seem more absurd than the asser- 
 tion, that we see, not with our eyes merely, but chiefly by the 
 medium of another organ, which the blind possess in as great 
 perfection as ourselves, and which at the moment of vision,
 
 PHILOSOPHY OF THE HUMAN MIND 381 
 
 may perhaps be absolutely at rest. It will not be surprising, 
 therefore, though the element which seems to me to form the 
 most important constituent of our notion of extension should in 
 the same manner seem a very unlikely one. 
 
 This element is our feeling of succession, or time, a feeling, 
 which necessarily involves the notion of divisibility or series of 
 parts, that is so essential a constituent of our more complex 
 notion of matter, and to which notion of continuous divisi- 
 bility, if the notion of resistance be added, it is scarcely possible 
 for us to imagine, that we should not have acquired, by this 
 union, the very notion of physical extension, that which has 
 parts, and that which resists our effort to grasp it. 
 
 That memory is a part of our mental constitution, and that * 
 we are thus capable of thinking of a series of feelings, as succes- 
 sive to each other, the experience of every moment teaches us 
 sufficiently. This succession frequently repeated, suggests im- i ^ 
 mediately, or implies the notion of length, not metaphorically, i 
 as is commonly said, but as absolutely as extension itself; and, 
 the greater the number of the successive feelings may have 
 been, the greater does this length appear. It is not possible for 
 us to look back on the years of our life, since they form truly a 
 
 P ***- j- ~^ 
 
 progressive series, without regarding them as a sort of length, ' 
 which is more distinct indeed, the nearer the succession of feel- y- 
 ings, may be to the moment at which we consider them, but ' l j - 
 which, however remote, is still felt by us as one continued length^ *.,-. 
 in the same manner, as when, after a journey of many hundred 
 miles, we look back, in our memory, on the distance over which 
 we have passed, we see, as it were, a long track of which some 
 parts, particularly the nearer parts, are sufficiently distinct, but 
 of which the rest seems lost in a sort of distant obscurity. The 
 line of our long journeying, or, in other words, that almost 
 immeasurable line of plains, hills, declivities, marshes, bridges, 
 woods, to endeavour to comprehend which in our thought, 
 seems an effort as fatiguing as the very journey itself, we 
 know well, can be divided, into those various parts; and, in like 
 manner, the progressive line of time or, in other words, the 
 continued succession, of which the joy, the hope, the fragrance,
 
 3 82 THOMAS BROWN 
 
 the regret, the melody, the fear, and innumerable other affec- 
 tions of the mind, were parts, we feel that we can mentally 
 divide into those separate portions of the train. Continuous 
 length and divisibility, those great elementary notions of space, 
 and of all that space contains, are thus found in every succes- 
 sion of our feelings. There is no language in which time is not 
 described as long or short, not from any metaphor for no 
 mere arbitrary metaphor can be thus universal and inevitable, 
 as a form of human thought but because it is truly impos- 
 sible for us to consider succession, without this notion of pro- 
 gressive divisibility attached to it; and it appears to us as ab- 
 surd to suppose, that by adding, to our retrospect of a week, 
 * the events of the month preceding, we do not truly lengthen the 
 succession, as it would be to suppose, that we do not lengthen 
 the line of actual distance, by adding, to the few last stages of a 
 long journey, the many stages that preceded it. 
 
 That which is progressive must have parts. Time, or succes- 
 sion, then involves the very notions of longitudinal extension 
 and divisibility, and involves these, without the notion of any 
 thing external to the mind itself; for though the mind of 
 man had been susceptible only of joy, grief, fear, hope, and the 
 other varieties of internal feeling, without the possibility of 
 being affected by external things, he would still have been capa- 
 ble of considering these feelings, as successive to each other, in a 
 long continued progression, divisible into separate parts. The 
 notions of length, then, and of divisibility, are not confined to 
 external things, but are involved in that very memory, by 
 which we consider the series of the past, not in the memory 
 of distant events only, but in those first successions of feeling, 
 by which the mind originally became conscious of its own per- 
 manence and identity. The notion of time, then, is precisely 
 coeval with that of the mind itself; since it is implied in the 
 knowledge of succession, by which alone the mind acquires the 
 knowledge of its own reality, as something more than the mere 
 sensation of the present moment. 
 
 Conceiving the notion of time, therefore, that is to say, of 
 feelings past and present, to be thus one of the earliest notions
 
 PHILOSOPHY OF THE HUMAN MIND 383 
 
 which the infant mind can form, so as to precede its notions of 
 external things, and to involve the notions of length and divisi- 
 bility, I am inclined to reverse exactly the process commonly 
 supposed; and, instead of deriving the measure of time from 
 extension, to derive the knowledge and original measure of 
 extension from time. That one notion or feeling of the mind 
 may be united indissolubly with other feelings, with which it 
 has frequently co-existed, and to which, but for this co-exist- 
 ence, it would seem to have no common relation, is sufficiently 
 shown by the phenomena of vision. 
 
 In what manner, however, is the notion of time peculiarly 
 associated with the simple sensation of touch, so as to form, 
 with it, the perception of extension? We are able, in the theory 
 of vision, to point out the co-existence of sensations which pro- 
 duce the subsequent union, that renders the perception of dis- 
 tance apparently immediate. If a similar co-existence of the 
 original sensations of touch, with the notion of continued and 
 divisible succession, cannot be pointed out in the present case, 
 the opinion which asserts it, must be considered merely as a 
 wild and extravagant conjecture. 
 
 The source of such a co-existence is not merely to be found, 
 but is at least as obvious, as that which is universally admitted 
 in the case of vision. 
 
 To proceed, then, The hand is the great organ of touch. 
 It is composed of various articulations, that are easily move- 
 able, so as to adapt it readily to changes of shape, in accommo- 
 dation to the shape of the bodies which it grasps. If we shut 
 our hand gradually, or open it gradually, we find a certain 
 series of feelings, varying with each degree of the opening or 
 closing, and giving the notion of succession of a certain length. 
 In like manner, if we gradually extend our arms, in various 
 directions, or bring them nearer to us again, we find that each 
 degree of the motion is accompanied with a feeling that is dis- 
 tinct, so as to render us completely conscious of the progres- 
 sion. The gradual closing of the hand, therefore, must neces- 
 sarily give a succession of feelings, a succession, which, of 
 itself, might, or rather must, furnish the notion of length in the
 
 384 THOMAS BROWN 
 
 manner before stated, the length being different, according to 
 the degree of the closing; and the gradual stretching out of the 
 arm gives a succession of feelings, which, in like manner, must 
 furnish the notion of length, the length being different ac- 
 cording to the degree of the stretching of the arm. To those 
 who have had opportunities of observing infants, I need not 
 say, how much use, or rather what constant use, the future 
 inquirer makes of his little fingers and arms; by the frequent 
 contraction of which, and the consequent renewal of the series 
 of feelings involved in each gradual contraction, he cannot fail 
 to become so well acquainted with the progress, as to distin- 
 guish each degree of contraction, and, at last, after innumerable 
 repetitions, to associate with each degree the notion of a certain 
 length of succession. The particular contraction, therefore, 
 when thus often repeated, becomes the representative of a cer- 
 tain length, in the same manner as shades of colour in vision 
 become ultimately representative of distance, the same prin- 
 ciple of association, which forms the combination in the one 
 case, operating equally in the other. 
 
 In these circumstances of acquired knowledge, after the 
 series of muscular feelings, in the voluntary closing of the hand, 
 has become so familiar, that the whole series is anticipated and 
 expected, as soon as the motion has begun, when a ball, or 
 any other substance, is placed for the first time in the infant's 
 hand, he feels that he can no longer perform the usual con- 
 traction, or, in other words, since he does not fancy that he 
 has muscles which are contracted, he feels that the usual series 
 of sensations does not follow his will to renew it, he knows 
 how much of the accustomed succession is still remaining; and 
 the notion of this particular length, which was expected, and 
 interrupted by a new sensation, is thus associated with the par- 
 ticular tactual feeling excited by the pressure of the ball, the 
 greater or less magnitude of the ball preventing a greater or 
 less portion of the series of feelings in the accustomed contrac- 
 tion. By the frequent repetition of this tactual feeling, as asso- 
 ciated with that feeling which attends a certain progress of con- 
 traction, the two feelings at last flow together, as in the
 
 PHILOSOPHY OF THE HUMAN MIND 385 
 
 acquired perceptions of vision; and when the process has been 
 repeated with various bodies innumerable times, it becomes, at 
 last, as impossible to separate the mere tactual feeling from the 
 feeling of length, as to separate the whiteness of a sphere, in 
 vision, from that convexity of the sphere, which the eye, of it- 
 self, would have been for ever incapable of perceiving. 
 
 As yet, however, the only dimension of the knowledge of 
 which we have traced the origin, is mere length; and it must 
 still be explained, how we acquire the knowledge of the other 
 dimensions. If we had had but one muscle, it seems to me very 
 doubtful whether it would have been possible for us to have 
 associated with touch any other notion than that of mere 
 length. But nature has made provision for giving us a wider 
 knowledge, in the various muscles, which she has distributed 
 over different parts, so as to enable us to perform motions in 
 various directions at the same instant, and thus to have co- 
 existing series of feelings, each of which series was before con- 
 sidered as involving the notion of length. The infant bends one 
 finger gradually on the palm of his hand; the finger, thus 
 brought down, touches one part of the surface of the palm, 
 producing a certain affection of the organ of touch, and a con- 
 sequent sensation; and he acquires the notion of a certain length, 
 in the remembered succession of muscular feelings during the 
 contraction; he bends another finger; it, too, touches a cer- 
 tain part of the surface of the palm, producing a certain feeling 
 of touch, that co-exists and combines, in like manner, with the 
 remembrance of a certain succession of muscular feelings. 
 When both fingers move together, the co-existence of the two 
 series of successive feelings, with each of which the mind is 
 familiar, gives the notion of co-existing lengths, which receive 
 a sort of unity, from the proximity in succession of the tactual 
 feelings in the contiguous parts of the palm which they touch, 
 feelings, which have before been found to be proximate, when 
 the palm has been repeatedly pressed along a surface, and the 
 tactual feelings of these parts, which the closing fingers touch 
 at the same moment, were always immediately successive, 
 as immediately successive, as any of the muscular feelings in
 
 386 THOMAS BROWN 
 
 the series of contraction. When a body is placed in the infant's 
 hand, and its little fingers are bent by it as before, sometimes 
 one finger only is impeded in its progress, sometimes two, some- 
 times three, and he thus adds to the notion of mere length, 
 which would have been the same, whatever number of fingers 
 had been impeded, the notion of a certain number of proximate 
 and co-existing lengths, which is the very notion of breadth; 
 and with these, according as the body is larger or smaller, is 
 combined always the tactual affection produced by the press- 
 ure of the body, on more, or fewer, of the interior parts of the 
 palm, and fingers, which had before become, of themselves, 
 representative of certain lengths, in the manner described ; and 
 the concurrence of these three varieties of length, in the single 
 feeling of resistance, in which they all seem to meet, when an 
 incompressible body is placed within the sphere of the clos- 
 ing fingers, however rude the notions of concurring dimen- 
 sions may be, or rather must be, as at first formed, seems at 
 least to afford the rude elements, from which, by the frequent 
 repetition of the feeling of resistance, together with the prox- 
 imate lengths, of which it has become representative, clearer 
 notions of the kind may gradually arise. 
 
 The progressive contractions of the various muscles which 
 move the arms as affording similar successions of feelings, may 
 be considered in precisely the same light, as sources of the 
 knowledge of extension; and, by their motion in various direc- 
 tions, at the same time with the motion of the fingers, they 
 concur powerfully, in modifying, and correcting, the informa- 
 tion received from these. The whole hand is brought, by the 
 motion of the arm, to touch one part of the face or body; it is 
 then moved, so as to touch another part, and with the frequent 
 succession of the simple feelings of touch, in these parts, is asso- 
 ciated the feeling of the intervening length, derived from the 
 sensations that accompanied the progressive contraction of the 
 arm. But the motion is not always the same; and, as the same 
 feeling of touch, in one part, is thus followed by various feelings 
 of touch in different parts, with various series of muscular feel- 
 ings between, the notion of length in various directions, that is
 
 PHILOSOPHY OF THE HUMAN MIND 387 
 
 to say, of length in various series commencing from one power, 
 is obtained in another way. That the knowledge of extension, 
 or in other words, the association of the notion of succession 
 with the simple feelings of touch, will be rude and indistinct at 
 first, I have already admitted; but it will gradually become 
 more and more distinct and precise; as we can have no doubt, 
 that the perception of distance by the eye is, in the first stages 
 of visual association, very indistinct, and becomes clearer after 
 each repeated trial. For many weeks or months, all is confu- 
 sion in the visual perceptions, as much as in the tactual and 
 muscular. Indeed, we have abundant evidence of this contin- 
 ued progress of vision, even in mature life, when, in certain 
 professions that require nice perceptions of distance, the power 
 of perception itself, by the gradual acquisitions which it ob- 
 tains from experience, seems to unfold itself more and more, in 
 proportion to the wants that require it. 
 
 It may be thought that the notion of time, or succession, is, in 
 this instance, a superfluous incumbrance of the theory, and that 
 the same advantage might be obtained, by supposing the mus- 
 cular feelings themselves, independently of the notion of their 
 succession, to be connected with the notion of particular 
 lengths. But this opinion, it must be remarked, would leave 
 the difficulty precisely as before ; and sufficient evidence in con- 
 futation of it, may be found in a very simple experiment, which 
 it is in the power of any one to make. The experiment I cannot 
 but consider as of the more value, since it seems to me strongly 
 corroborative of the theory which I have ventured to propose ; 
 for it shows, that, even after all the acquisitions which our 
 sense of touch has made, the notion of extension is still modi- 
 fied, in a manner the most striking and irresistible, by the mere 
 change of accustomed time. Let any one, with his eyes shut, 
 move his hand, with moderate velocity, along a part of a table, 
 or any other hard smooth surface; the portion over which he 
 presses, will appear of a certain length; let him move his hand 
 more rapidly, the portion of the surface pressed will appear 
 less; let him move his hand very slowly, and the length, accord- 
 ing to the degree of the slowness, will appear increased, in a
 
 388 THOMAS BROWN 
 
 most wonderful proportion. In this case, there is precisely the 
 same quantity of muscular contraction, and the same quantity 
 of the organ of touch compressed, whether the motion be rapid, 
 moderate, or slow. The only circumstance of difference is the 
 time occupied in the succession of the feelings; and this differ- 
 ence is sufficient to give complete diversity to the notion of 
 length. 
 
 If any one, with his eyes shut, suffer his hand to be guided by 
 another, very slowly along any surface unknown to him, he will 
 find it impossible to form any accurate guess as to its length. 
 But it is not necessary, that we should be previously unac- 
 quainted with the extent of surface, along which the motion is 
 performed; for the illusion will be nearly the same, and the 
 experiment, of course, be still more striking, when the motion is 
 along a surface with which we are perfectly familiar, as a book 
 which we hold in our hand, or a desk at which we are accus- 
 tomed to sit. 
 
 This experiment is well fitted to show the influence of mere 
 difference of time, in our estimation of longitudinal extent. It 
 is an experiment, tried, unquestionably, in most unfavourable 
 circumstances, when our tactual feelings, representative of ex- 
 tension, are so strongly fixed, by the long experience of our 
 life; and yet, even now, it will be found, on moving the hand, 
 slowly and rapidly, along the same extent of surface, though 
 with precisely the same degree of pressure in both cases, that 
 it is as difficult to conceive the extent, thus slowly and rapidly 
 traversed, to be the same, as it is difficult to conceive the extent 
 of visual distance to be exactly the same when we look alternately 
 through the different ends of an inverted telescope. If, when all 
 other circumstances are the same, the different visual feelings, 
 arising from difference of the mere direction of light, be repre- 
 sentative of length in the one case, the longer or shorter suc- 
 cession of time, when all other circumstances are the same, has 
 surely as much reason to be considered a representative of it, 
 in the other case. 
 
 Are we, then, to believe, that feeling of extension, or in 
 other words, of the definite figure of bodies, is a simple
 
 PHILOSOPHY OF THE HUMAN MIND 389 
 
 feeling of touch, immediate, original, and independent of 
 time; or is there not rather reason to think, that it is a 
 compound feeling, of which time, that is to say, our notion 
 of succession, is an original element 
 
 PART III 
 
 CHAPTER I. SECTION II. SIMPLE AND RELA- 
 TIVE SUGGESTION 
 
 OUR various states or affections of the mind, I have already 
 divided into two classes, according to the nature of the circum- 
 stances which precede them, the External and the Internal, 
 and this latter class into two orders, our Intellectual 
 States of Mind, and our Emotions. It is with the intellectual 
 phenomena that we are at present concerned; and this order I 
 would arrange under two generic capacities, that appear to me 
 to comprehend or exhaust the phenomena of the order. The 
 whole order, as composed of feelings which arise immediately, 
 in consequence of certain former feelings of the mind may be 
 technically termed, in reference to these feelings which have 
 induced them, Suggestions; but, in the suggested feelings them- 
 selves, there is one striking difference. If we analyze out trains 
 of intellectual thought exclusively of the Emotions which may 
 co-exist or mingle with them, and of sensations that may be 
 accidentally excited by external objects, we shall find them to 
 be composed of two very distinct sets of feelings, one set of 
 which are mere conceptions or images of the past, that rise, 
 image after image in regular sequence, but simply in succession, 
 without any feeling of relation necessarily involved, while the 
 perceptions of relation, in the various objects of our thought, 
 form another set of feelings, of course as various as the relations 
 perceived. Conceptions and relations, it is with these, and 
 with these alone, that we are intellectually conversant. There 
 is thus an evident ground for the arrangement of the internal 
 suggestions, that form our trains of thought, under two heads,
 
 390 THOMAS BROWN 
 
 according as the feeling excited directly by some former feeling 
 may be either a simple conception, in its turn, perhaps, giving 
 place to some other conception as transient; or may be, the 
 feeling^ of ajrelation which two or more objects of our thought 
 -fife'consideredByTis as bearing to each other. There is, in 
 short, in the mind, a capacity of association; or, as for reasons 
 afterwards to be stated, I would rather term it, the capacity 
 of Simple Suggestion, by which feelings formerly existing, 
 are revived, in consequence of the mere existence of other feel- 
 ings, as there is also a capacity of feeling resemblance, differ- 
 ence, proportion, or relation in general, when two or more 
 external objects, or two or more feelings of the mind itself, are 
 considered by us, which mental capacity, in distinction 
 from the former, I would term the capacity of Relative Sugges- 
 tion; and of these simple and relative suggestions, the whole of 
 our intellectual trains of thought are composed. As I am no 
 lover of new phrases, when the old can be used without danger 
 of mistake, I would very willingly substitute for the phrase, 
 relative suggestion, the term comparison, which is more familiar, 
 and expresses very nearly the same meaning. But comparison, 
 though it involve the feeling of relation, seems also to imply a 
 voluntary seeking for some relation, which is far from necessary 
 to the mere internal suggestion or feeling of the relation itself. 
 The resemblance of two objects strikes me, indeed, when I am 
 studiously comparing them; but it strikes me also, with not less 
 force, on many other occasions, when I had not previously been 
 forming the slightest intentional comparison. I prefer, there- 
 fore, a term which is applicable alike to both cases, when a rela- 
 tion is sought, and when it occurs, without any search or desire 
 of finding it. 
 
 The term judgment, in its strict philosophic sense, as the mere 
 perception of relation, is more exactly synonymous with the 
 phrase which I have employed, and might have been substi- 
 tuted with safety, if the vulgar use of the term, in many vague 
 significations, had not given some degree of indistinctness even 
 to the philosophical use of it. I may remark, too, that in our 
 works of logic and intellectual physiology, judgment and reason-
 
 PHILOSOPHY OF THE HUMAN MIND 391 
 
 ing are usually discussed separately, as if there were some es- 
 sential difference of their nature; and, therefore, since I include 
 them both, in the relative suggestions of which I shall after- 
 wards have to treat, it seems advisable, not to employ for the 
 whole, a name which is already appropriated, and very gener- 
 ally limited, to a part. As the rise in the mind of the feeling of 
 relation, from the mere perception or conception of objects, is 
 however, what I mean to denote by the phrase Relative Sugges- 
 tion; and as judgment, in its strictest sense, is nothing more than 
 this feeling of relation, or any two or more objects, consid- 
 ered by us together, I shall make no scruple to use the 
 shorter and more familiar term, as synonymous when there can 
 be no danger of its being misunderstood. 
 
 The intellectual states of the mind, then, to give a brief illus- 
 tration of my division, I consider as all referable to two generic 
 susceptibilities, those of Simple Suggestion and Relative Sug- 
 gestion. Our perception or conception of one object excites, of 
 itself, and without any known cause, external to the mind, the 
 conception of some other object, as when the mere sound of our 
 friend's name, suggests to us the conception of our friend him- 
 self, in which case, the conception of our friend, which fol- 
 lows the perception of the sound, involves no feeling of any 
 common property with the sound which excites it, but is pre- 
 cisely the same state of mind, which might have been induced, 
 by various other previous circumstances, by the sight of the 
 chair on which he sat, of the book which he read to us, of 
 the landscape which he painted. This is Simple Suggestion. 
 
 But, together with this capacity of Simple Suggestion, by 
 which conception after conception arises in the mind, pre- 
 cisely in the same manner, and in the same state, as each 
 might have formed a part of other trains, and in which the par- 
 ticular state of mind that arises by suggestion does not neces- 
 sarily involve any consideration of the state of mind which pre- 
 ceded it, there is a suggestion of a very different sort, which 
 in every case involves the consideration, not of one phenome- 
 non of mind, but of two or more phenomena, and which con- 
 stitutes the feeling of agreement, disagreement, or relation of
 
 392 THOMAS BROWN 
 
 some sort. I perceive, for example, a horse and a sheep at the 
 same moment. The perception of the two is followed by that 
 different state of mind which constitutes the feeling of their 
 agreement in certain respects, or of their disagreement in cer- 
 tain other respects. I think of the square of the hypotenuse of a 
 right-angled triangle, and of the squares of the two other sides; 
 I feel the relation of equality. I see a dramatic representa- 
 tion; I listen to the cold conceits which the author of the trag- 
 edy, in his omnipotent command over warriors and lovers of his 
 own creation, gives to his hero, in his most impassioned situa- 
 tions; I am instantly struck with their unsuitableness to the 
 character and the circumstances. All the intellectual succes- 
 sions of feeling, in these cases, which constitute the perception 
 of relation, differ from the results of simple suggestion in neces- 
 sarily involving the consideration of two or more objects or 
 affections of mind, that immediately preceded them. I may 
 think of my friend, in the case of simple suggestion, that is 
 to say, my mind may exist in the state which constitutes the 
 conception of my friend, without that previous state which 
 constitutes the perception of the sound of his name; for the 
 conception of him may be suggested by various objects and 
 remembrances. But I cannot in the cases of relative suggestion, ^ 
 think of the resemblance of a horse and a sheep; of the propor- 
 tion of the squares of the sides of a right-angled triangle; or of 
 the want of the truth of nature in the expressions of a dramatic 
 hero, without those previous states of mind, which constitute 
 the conceptions of a horse and a sheep of the sides of the 
 triangle, or of the language of the warrior or lover, and the 
 circumstances of triumph, or hope, or'-^espair, in which he is 
 exhibited to us by the creative artist. 
 
 With these two capacities of suggested feelings, simple and 
 relative, which are all that truly belong to the class of intel- 
 lectual states of the mind, various emotions may concur, par- 
 ticularly that most general of all emotions, the emotion of 
 desire, in some one or other of its various forms. According as 
 this desire does or does not concur with them, the intellectual 
 states themselves appear to be different; and, by those who do
 
 PHILOSOPHY OF THE HUMAN MIND 393 
 
 not make the necessary analysis, are supposed, therefore, to be 
 indicative of different powers. By simple suggestion, the 
 images of things, persons, events, pass in strange and rapid 
 succession; and a variety of names, expressive of different 
 powers, conception, association, memory, have been 
 given to this one simple law of our intellectual nature. But, 
 when we wish to remember some object; that is to say, when 
 we wish our mind to be affected in that particular manner, 
 which constitutes the conception of a particular thing, or per- 
 son, or event, or when we wish to combine new images, in 
 some picture of fancy, this co-existence of desire, with the 
 simple course of suggestion, which continues still to follow its 
 own laws, as much as when no desire existed with it, seems 
 to render the suggestion itself different; and recollection, and 
 imagination, or fancy, which are truly, as we shall afterwards 
 find, nothing more than the union of the suggested conceptions 
 with certain specific permanent desires, are to us, as it were, 
 distinct additional powers of our mind, and are so arranged in 
 the systems of philosophers, who have not made the very sim- 
 ple analysis, which alone seems to be necessary for a more pre- 
 cise arrangement. 
 
 In like manner, those suggestions of another class, which 
 constitute our notions of proportion, resemblance, difference, 
 and all the variety of relations, may arise, when we have had 
 no previous desire of tracing the relations, or may arise after 
 that previous desire. But, when the feelings of relation seem to 
 us to arise spontaneously, they are not in themselves different 
 from the feelings of relation, that arise, in our intentional com- 
 parisons or judgments, in the longest series of ratiocination. 
 Of such ratiocination, they are truly the most important ele- 
 ments. The permanent desire of discovering something un- 
 known, or of establishing, or confuting, or illustrating, some 
 point of belief or conjecture, may co-exist, indeed, with the con- 
 tinued series of relations that are felt, but does not alter the 
 nature of that law, by which these judgments, or relative sug- 
 gestions, succeed each other. 
 
 There is no power to be found, but only the union of certain
 
 394 THOMAS BROWN 
 
 intellectual states of the mind, with certain desires, a species 
 of combination not more wonderful in itself, than any other 
 complex mental state, as when we, at the same moment, see 
 and smell a rose, or listen to the voice of a friend, who has 
 been long absent from us, and see, at the same moment, that 
 face of affection, which is again giving confidence to our heart, 
 and gladness to our very eyes. 
 
 Our intellectual states of mind, then, are either those resem- 
 blances of past affections of the mind, which arise by simple 
 suggestion, or those feelings of relation, which arise by what I 
 have termed relative suggestions, the one set resulting, in- 
 deed, from some prior states of the mind, but not involving, 
 necessarily, any consideration of these previous states of mind, 
 which suggested them, the other set, necessarily involving 
 the consideration of two or more objects, or two or more affec- 
 tions of mind, as subjects of the relation which is felt.
 
 JOHANN FRIEDRIGH HERBART 
 
 (1776-1841) 
 
 A TEXT BOOK IN PSYCHOLOGY 
 
 Translated from the German * by 
 MARGARET K. SMITH 
 
 PART FIRST. FUNDAMENTAL PRINCIPLES 
 
 CHAPTER I. THE CONDITION OF CONCEPTS, 
 WHEN THEY ACT AS FORCES 
 
 10. CONCEPTS become forces when they resist one another. 
 This resistance occurs wjien two or more opposed concepts 
 encounter one another. 
 
 At first let us take this proposition as simply as possible. In 
 this connection, therefore, we shall not think of complex nor of 
 compound concepts of any kind whatever; nor of such as indi- 
 cate an object with several characteristics, neither of anything 
 in time nor space, but of entirely simple concepts or sensations 
 - e.g., red, blue, sour, sweet, etc. It is not our purpose to con- 
 sider the general notions of the above-mentioned sensations, 
 but to consider such representations as may result from an 
 instantaneous act of sense-perception. 
 
 Again, the question concerning the origin of the sensations 
 mentioned does not belong here, much less has the discussion 
 to do with the consideration of anything else that might have 
 previously existed or occurred in the soul. 
 
 The proposition as it stands is that opposed concepts resist 
 one another. Concepts that are not opposed e.g., a tone and 
 a color may exist, in which case it will be assumed that such 
 
 * From Lehrbuch zer Psychologic, Lpg., 1816; 3 Aufl. 1882. Reprinted here 
 from J. F. Herbart's A Text-Book in Psychology, translated by M. K. Smith, 
 New York, D. Appleton & Co., 1891.
 
 396 JOHANN FRIEDRICH HERBART 
 
 concepts offer no resistance to one another. (Exceptions to this 
 latter proposition may occur, of which more hereafter.) 
 
 Resistance is an expression of force. To the resisting con- 
 cept, however, its action is quite accidental ; it adjusts itself to 
 the attack which is mutual among concepts, and which is deter- 
 mined by the degree of opposition existing between them. This 
 opposition may be regarded as that by which they are affected 
 collectively. In themselves, however, concepts are not forces. 
 
 11. Now, what is the result of the resistance mentioned? 
 Do concepts partially or wholly destroy one another, or, not- 
 withstanding the resistance, do they remain unchanged? 
 
 Destroyed concepts are the same as none at all. However, if, 
 notwithstanding the mutual attack, concepts remain un- 
 changed, then one could not be removed or suppressed by an- 
 other (as we see every moment that they are). Finally, if all 
 that is conceived of each concept were changed by the contest, 
 then this would signify nothing more than, at the beginning, 
 quite another concept had been present in consciousness. 
 
 The presentation (concept), then, must yield without being 
 destroyed i.e., the real concept is changed into an effort to 
 present itself. 
 
 Here it is in effect stated that, as soon as the hindrance 
 yields, the concept by its own effort will again make its appear- 
 ance in consciousness. In this lies the possibility (although not 
 for all cases the only ground) of reproduction. 
 
 12. When a concept becomes not entirely, but only in part, 
 transformed into an effort, we must guard against considering 
 this part as a severed portion of the whole concept. It has cer- 
 tainly a definite magnitude (upon the knowledge of which 
 much depends), but this magnitude indicates only a degree of 
 the obscuration of the whole concept. If the question be in 
 regard to several parts of one and the same concept, these parts 
 must not be regarded as different, severed portions, but the 
 smaller divisions may be regarded as being contained in the 
 larger. The same is true of the remainders after the collisions 
 
 i.e., of those parts of a concept which remain unobscured, 
 for those parts are also degrees of the real concept.
 
 A TEXT BOOK IN PSYCHOLOGY 397 
 
 CHAPTER II. EQUILIBRIUM AND MOVEMENT OF 
 
 CONCEPTS 
 
 13. WHEN a sufficiency of opposition exists between con- 
 cepts, the latter are in equilibrium. They come only gradually 
 to this point. The continuous change of their degree of obscura- 
 tion may be called their movement. 
 
 The statics and mechanics of the mind have to do with the 
 calculation of the equilibrium and movement of the concepts. 
 
 14. All investigations into the statics of the mind begin with 
 two different quantitative factors, viz., the sum (or the aggre- 
 gate amount) of the_ resistances and the j-atio of their limita- 
 tion. The former is the quantity which rises from their en- 
 counter, to be divided between the opposing concepts. If one 
 knows how to state it, and knows also the ratio in which the dif- 
 ferent concepts yield in the encounter, then, by a simple calcu- 
 lation in proportion, the statical point of each concept i.e., 
 the degree of its obscuration in equilibrium may be found. 
 
 15. The sum as well as the ratio of the mutual limitation 
 depends upon the strength of each individual concept which is 
 affected in inverse ratio' to its strength, and upon the degree of 
 opposition between the two concepts. For their influence upon 
 each other stands in direct ratio to the strength of each. 
 
 The principle determining the sum of the mutual limitation 
 is, that it shall be considered as small as possible, because all 
 concepts strive against suppression, and certainly submit to no 
 more of it than is absolutely necessary. 
 
 1 6. By actual calculation, the remarkable result is obtained 
 that, in the case of the two concepts, the one never entirely 
 obscures the other, but, in the case of three or more, one is v 
 easily obscured, and can be made as ineffective notwith- 
 standing its continuous struggle as if it were not present a$/- 
 all. Indeed, this obscuration may happen to a large number o 
 concepts as well as to one, and may be effected through the 
 agency of two, and even through the combined influence of 
 concepts less strong than those which are suppressed. 
 
 Here the expression "threshold of consciousness" must be
 
 398 JOHANN FRIEDRICH HERBART 
 
 explained, as we shall have occasion to use it. A concept is in 
 consciousness in so far as it is not suppressed, but is an actual 
 representation. When it rises out of a condition of complete 
 suppression, it enters into consciousness. Here, then, it is on 
 the threshold of consciousness. It is very important to deter- 
 mine by calculation the degree of strength which a concept 
 must attain in order to be able to stand beside two or more 
 stronger ones exactly on the threshold of consciousness, so that, 
 at the slightest yielding of the hindrance, it would begin to rise 
 into consciousness. 
 
 NOTE. The expression "A concept is in consciousness" must 
 be distinguished from that, "I am conscious of my concept." To the 
 latter belongs inner perception ; to the former not. In psychology, 
 we need a word that will indicate the totality of all simultaneous 
 actual presentations. No word except consciousness can be found 
 for this purpose. 
 
 Here we are obliged to be content with a circumlocution and 
 this all the more, because the inner perception which is usually 
 attributed to consciousness has no fixed limit where it begins or 
 ceases, and, moreover, the act of perceiving is not itself perceived ; 
 so that, since we are not conscious of it in ourselves, we must exclude 
 it from consciousness, although it is an active knowing, and in no 
 way a restricted or suppressed concept. 
 
 17. Among the many, and, for the most part, very compli- 
 cated laws underlying the movement of concepts, the following 
 is the simplest: 
 
 While the arrested portion (Hemmungssumme) of the concept 
 sinks, the sinking part is at every moment proportional to the 
 part un suppressed. 
 
 By this it is possible to calculate the whole course of the sink- 
 ing even to the statical point. 
 
 NOTE. Mathematically, the above law may be expressed: 
 <r=S in which S = the aggregate amount suppressed, 
 
 / = the time elapsed during the encounter, a- = the suppressed portion 
 of all the concepts in the time indicated by t.
 
 A TEXT BOOK IN PSYCHOLOGY 399 
 
 As the latter quantity is apportioned among the individual con- 
 cepts, it is found that those which fall directly beneath the statical 
 threshold (16) are very quickly driven thence, while the rest do not 
 reach exactly their statical point in any given finite time. On ac- 
 count of this latter circumstance, the concepts in the mind of a man 
 of most equable temperament are, while he is awake, always in a 
 state of gentle motion. This is also the primary reason why the inner 
 perception never meets an object which holds it quite motionless. 
 
 18. When to several concepts already near equilibrium a 
 new one comes, a movement arises which causes them to sink 
 for a short time beneath their statical point, after which they 
 quickly and entirely of themselves rise again something as a 
 liquid, when an object is thrown into it, first sinks and then 
 rises. In this connection several remarkable circumstances 
 occur: 
 
 19. First, upon an occasion of this kind, one of the older con- 
 cepts may be removed entirely out of consciousness even by a 
 new concept that is much weaker than itself. In this case, how- 
 ever, the striving of the suppressed concept is not to be consid- 
 ered wholly ineffective, as shown above (see 16) ; it works with 
 all its force against the concepts in consciousness. Although its 
 object is not conceived, it produces a certain condition of con- 
 sciousness. The way in which these concepts are removed out 
 of consciousness and yet are effective therein may be indicated 
 by the expression, "They are on the mechanical threshold." 
 The threshold mentioned above (16) is called for the sake of 
 distinction the statical threshold. 
 
 NOTE. If the concepts on the statical threshold acted in the 
 same way as on the mechanical threshold we should find ourselves 
 in a state of the most intolerable uneasiness, or rather the body 
 would be subjected to a condition of tension that must in a few 
 moments prove fatal, even as under present conditions sudden fright 
 will sometimes cause death; for all the concepts which, as we are 
 accustomed to say, the memory preserves, and which we well know 
 can upon the slightest occasion be reproduced, are in a state of 
 incessant striving to rise, although the condition of consciousness is 
 not at all affected by them.
 
 400 JOHANN FRIEDRICH HERBART 
 
 20. Second, the time during which one or more concepts 
 linger upon the mechanical threshold can be extended if a series 
 of new, although weaker, concepts come in succession to them. 
 
 Every employment to which we are unaccustomed puts us in 
 this condition. The earlier concepts are pressed back of the 
 later ones. The former, however, because they are the stronger, 
 remain tense, affect the physical organism more and more, and 
 finally make it necessary that the employment cease, when the 
 old concepts immediately rise, and we experience what is called 
 a feeling of relief which depends in part upon the physical 
 organism, although the first cause is purely psychological. 
 
 21. Third, when several concepts are driven in succession to 
 the mechanical threshold, several sudden successive changes in 
 the laws of reciprocal movements arise. 
 
 In this way is to be explained the fact that the course of our 
 thoughts is so often inconsequent, abrupt, and apparently irre- 
 gular. This appearance deceives in the same way as the wan- 
 dering of the planets. The conformity to law in the human 
 mind resembles exactly that in the firmament. 
 
 NOTE. As a counterpart to the concepts which sink simul- 
 taneously are to be observed those which rise simultaneously, 
 especially when they rise free i.e., when a restricting environ- 
 ment or a general pressure suddenly disappears. With the rising 
 the amount of suppression increases. Hence, in the case of three, 
 one 'may be, as it were, bent back, and under certain conditions 
 may sink quite to the threshold. Their elevation is greater than 
 the depression to which, sinking together, they would have pressed 
 one another, because in sinking the sum of their mutual limitation 
 depends upon the total strength, which in the gradual rising is 
 not the case. 
 
 CHAPTER III. COMPLICATIONS AND BLEN DINGS 
 
 22. THE easily conceivable metaphysical reason why op- 
 posed concepts resist one another is the unity of the soul, of 
 which they are the self-preservations. This reason explains with- 
 out difficulty the combination of our concepts (which combina-
 
 A TEXT BOOK IN PSYCHOLOGY 401 
 
 tion is known to exist). If, on account of their opposition, they 
 did not suppress one another, all concepts would compose but 
 one act of one soul ; and, indeed, in so far as they are not divided 
 into a manifold by any kind of arrests whatever, they really con- 
 stitute but one act. Concepts that are on the threshold of con- 
 sciousness can not enter into combination with others, as they 
 are completely transformed into effort directed against other 
 definite concepts, and are thereby, as it were, isolated. In con- 
 sciousness, however, concepts combine in two ways'^First, con- 
 cepts which are not opposed or contrasted with one another (as 
 a tone and a color) so far as they meet unhindered, form a cotg- 
 plex; second ? contrasted concepts [e.g., red and yellow], in so far 
 as they are effected neither by accidental foreign concepts nor 
 by unavoidable opposition, become blended (Juse). 
 
 Complexes may be complete; blendings (fusions) from their 
 nature must always be (more or less) incomplete. 
 
 NOTE. Of such complexes as are partially or almost complete, 
 we have remarkable instances in the concepts of things with several 
 characteristics and of words used as signs of thoughts. In the 
 mother-tongue the latter, words and thoughts, are so closely con- 
 nected that it would appear that we think- by means of words. 
 (Concerning both examples more hereafter.) Among the blendings 
 are especially remarkable, partly those which include in themselves 
 an aesthetic relation (which, taken psychologically, is created at the 
 same time with the blending), partly those which involve succession, 
 in which serial forms have their origin. 
 
 23. That which is complicated or blended out of several con- 
 cepts furnishes an aggregate of force, and for this reason works 
 according to quite other statical and mechanical laws than 
 those according to which the individual concepts would have 
 acted. Also the thresholds of consciousness change according 
 to the complex or blending (fusion), so that on account of a 
 combination a concept of the very weakest kind may be able to 
 remain and exert an influence in consciousness. 
 
 NOTE i. The computation for complexes and blendings de- 
 pends upon the same principles as that for simple concepts; it is,
 
 402 JOHANN FRIEDRICH HERBART 
 
 however, much more intricate, especially for the reason that in the 
 case of incomplete combinations the forces as well as their arrests 
 are only partially interwoven with one another (and do not fully 
 enter as factors into the product). 
 
 NOTE 2. Combinations of concepts consist not only of two or 
 three members, but they often contain many members in very un- 
 equal degrees of complication, or blending, in which case no calcula- 
 tion can estimate the multiplicity. Nevertheless, from the latter, 
 the simplest cases may be chosen and the more intricate ones esti- 
 mated according to them. For every science the simplest laws are 
 the most important. 
 
 24. Problem: After an encounter between two concepts, P 
 and II, the remainders, r and p, are blended (or incompletely 
 united). The problem is to indicate what help one of the two 
 concepts, in case it should be still more suppressed, would 
 receive from the other. 
 
 NOTE. Solution : Let P be the helping concept; it helps with a 
 force equal to r, but n can only appropriate this force in the ratio of 
 
 , ', ft II. Hence through P, II receives the help jj, and in the same way 
 
 P receives from n the help r . 
 U P 
 
 The proof lies immediately in the analysis of the ideas. It is 
 plain that the two remainders, r and p, taken together, deter- 
 mine the degree of union between the two concepts. One of 
 them is the helping force; the other, compared with the con- 
 cept to which it belongs, is to be considered as a fraction of the 
 whole; and, of the totality of help which could be rendered by 
 the first remainder, it yields that portion which here attains 
 efficient activity. 
 
 25. The following principles may be observed here: 
 
 a. Beyond the point of union no help extends its influence. 
 
 If the concept II has more clearness in consciousness than the 
 remainder p indicates, then by striving of the concept P, which 
 might come to the help of the former, already more than 
 enough has been done; hence for the present it exerts no more 
 influence.
 
 A TEXT BOOK IN PSYCHOLOGY 403 
 
 b. The farther the one of the concepts is below the point of 
 union, so much the more effectively does the other help. 
 
 NOTE. This gives the following differential equation: 
 rpp o) , , 
 
 u dt==d<a > 
 
 ( rt\ 
 whence by integration <0=p ( _ -=) 
 
 This equation contains the germ of manifold investigations 
 which penetrate the whole of psychology. It is indeed so simple 
 that it can never really occur in the human soul, but alMnvestiga- 
 tions into applied mathematics begin with such simple presupposi- 
 tions as only exist in abstraction e.g., the mathematical lever, 
 or the laws of bodies falling in a vacuum. Here merely the influence 
 of the help is considered, which, if everything depended upon it 
 alone, would bring into consciousness during the time t a quantity 
 w from IT. Besides, if we take into consideration the single circum- 
 stance that n meets with an unavoidable arrest from other con- 
 cepts, then the calculation becomes so complicated that it can be 
 only approximately solved by an integration of the following form : 
 
 It is self-evident that it much more nearly expresses the facts 
 which are to be observed experimentally. 
 
 26. The foregoing contains the foundation of the theory of 
 mediate reproduction, which, according to ordinary language, 
 is derived from the association of ideas or concepts. Before pur- 
 suing this further we must mention immediate reproduction - 
 i.e., that reproduction which by its own force follows upon the 
 yielding of the hindrances. The ordinary case is that a concept 
 gained by a new act of perception causes the old concept of the 
 same or of a similar object to rise into consciousness. This 
 occurs when the concept furnished by the new act of perception 
 presses back everything present in consciousness opposed to 
 the old concept, which is similar to the new one. Then, without 
 further difficulty, the old concept rises of itself. From this are 
 to be observed the following conditions, which are to be found 
 by calculation, of which, however, no idea can be given here:
 
 4 o 4 JOHANN FRIEDRICH HERBART 
 
 a. In the beginning the rising is in proportion to the square 
 of the time, if the new act of perception occurs suddenly; but to 
 the cube of the time, if the latter (as is usual) is formed by a 
 gradual and lingering act of apprehension. 
 
 b. The course of the rising is adjusted principally to the 
 strength of the concept furnished by the new act of perception 
 in proportion to the opposing one which it has pressed back; but 
 the individual strength of the rising concept only has influence 
 under special conditions. It can, as it were, only use this 
 strength in the free space which is given to it. 
 
 c. The rising concept blends as such with the concept, similar 
 to it, furnished by the new act of perception. Since it does not 
 rise entirely, however, the blending is incomplete. 
 
 d. The fact that immediate reproduction is not limited 
 entirely to the old concept of exactly the same kind, but ex- 
 tends to the more or less similar so far as to receive partial free- 
 dom from the new act of perception, is of special importance. 
 The whole reproduction may be indicated by the name of 
 vaulting (or arching). In the case of a long duration, or of a fre- 
 quent repetition of a new act of perception, a second important 
 process, which we call tapering (or pointing), follows. The pe- 
 culiarity of this latter consists in the fact that the concepts 
 which are less similar are again arrested by the concepts received 
 through the new act of perception, as the old concepts bring 
 with them into consciousness others which are opposed to the 
 new, so that finally the concept that is entirely homogeneous 
 finds itself alone favored, and forms, as it were, a tapering sum- 
 mit where the highest point of the vault (or arch) was hereto- 
 fore. 
 
 27. Where the circumstances allow, with this immediate 
 reproduction is united that mediate reproduction mentioned in 
 25. The concept P, mentioned above, is reproduced immedi- 
 ately (i.e., without the mediation of others), then the free space 
 allowed it may be regarded as that r (spoken of in 25) or as a 
 force which strives to raise the II blended with it to its point of 
 blending p.
 
 A TEXT BOOK IN PSYCHOLOGY 405 
 
 NOTE. As the free space gradually increasing (and again 
 decreasing) is given, we must for the present observation regard 
 
 ( ri\ 
 
 r in the formula W=P as a variable quantity, and indeed 
 
 \i e n/ 
 
 as a function of that quantity upon which the propositions in 26 
 depend. 
 
 28. The most important applications of the previous theories 
 are, if with different remainders r, r f , r", etc., of one and the 
 same concept P several II, II', n", etc., are united, by which, for 
 the sake of brevity, we may assume the remainders of the lat- 
 ter, viz., p, p', p", to be equal; also, II, II', etc., may be equal. 
 
 A concept acts upon several united "with it in the same series 
 according to the time in which its remainders (by which it is united 
 with those others according to quantity] stand. 
 
 NOTE. In order to avoid diffuseness, this most important law 
 is here only very incompletely expressed in words. We recognize it 
 
 ( -rt\ 
 better and more clearly in the formula given: w = p ( ), if 
 
 VI & 1 J/ 
 
 instead of one r we substitute different smaller and greater, r, r', r", 
 etc. But the more exact calculation mentioned in 25 shows that the 
 n, n', n", etc., blended with them, not only rise, but sink again, as 
 it were, to make place for each other, in and the order of r, r', r", etc. 
 
 29. Here is discovered the ground of the genuine reproduc- 
 tion or of memory so far as it brings to us a series of concepts 
 in the same order in which they were first received. In order to 
 comprehend this, we must consider what union arises among 
 several concepts that are successively given. 
 
 Let a series, a, b, c, d, be given by perception; then, from the 
 first movement of the perception and during its continuance, a 
 is exposed to an arrest from other concepts already in conscious- 
 ness. In the mean time, a, already partially sunken in con- 
 sciousness, became more and more obscured when b came to it. 
 This b at first, unobscured, blended with the sinking a; then 
 followed c, which itself unobscured, united with b, which was 
 becoming obscured, and also with a, which was still more 
 obscured. Similarly followed d, to become united in different
 
 4 o6 JOHANN FRIEDRICH HERBART 
 
 degrees with a, b, c. From this arises a law for each of these 
 concepts that states how, after the whole series has been, for a 
 time, removed out of consciousness, upon the re-emergence of 
 one of the concepts of such a series into consciousness, every 
 other concept of the same series is called up. Let it be assumed 
 that a rises first, then it is united more with b, less with c, and 
 still less with d; backward, however, b, c, and d are blended 
 collectively in an unobscured condition with the remainders of 
 a; hence a seeks to bring them all again into an unobscured 
 condition [i.e., into full consciousness]. But a acts the most 
 quickly and strongly upon b, more slowly upon c, still more 
 slowly upon d, etc., by which close investigation shows that b 
 sinks again, while c rises, even as c sinks when d rises; in short, 
 the series follows in the same order as first given. On the con- 
 trary, let us assume that c is originally reproduced, then c acts 
 upon d and the following members of the series exactly in the 
 same way as was indicated in the case of a i.e., the series 
 c, d, etc., unfolds gradually in the order of its succession. On 
 the contrary, b and a experience quite another influence. The 
 unobscured c was blended with their different remainders. 
 Then c acts upon them with its whole strength, and without 
 delay, but only to call back the remainders of a and b united with 
 it, to bring a part of b and a smaller part of a into consciousness. 
 Thus it happens that when we remember something in the mid- 
 dle of a known series, the preceding part of the series presents 
 itself all at once in a lessened degree of clearness, while the por- 
 tion following comes before the mind in the same order as the 
 series it brings with it. But the series never runs backward ; an 
 anagram from a well-comprehended word never originates 
 without intentional effort. 
 
 30. Several series may cross one another, e.g., a, b, c, d, e, and 
 ct, ft, c, 8, e, in which c is common to the two series. If c were 
 reproduced alone, it would strive to call up d and e as well as o 
 and e. If, however, b comes into consciousness first, then the 
 first series comes decidedly forward on account of the united 
 help of b and c, yet the oppositions among the members of both 
 series, in this case, have each their own influence.
 
 A TEXT BOOK IN PSYCHOLOGY 407 
 
 We may remark that, to the simple type or model here given, 
 a variety of complicated psychological occurrences may be 
 adjusted. The same c can be held as the common point of inter- 
 section for many hundred series. On account of the manifold 
 oppositions in these series, the common c may cause none of the 
 members to rise perceptibly, but so soon as b and a come for- 
 ward, determining c more closely, the indecision will disappear, 
 and the uppermost series will really come before the mind. 
 
 31. The foregoing depends upon the difference presupposed 
 in the remainders r, r', r", etc. (28) . But in order that this dif- 
 ference may have its influence, the concept to which these re- 
 mainders belong must come forward sufficiently into conscious- 
 ness. Let it be granted that it is arrested to such a degree that 
 its active representation amounts to no more than that of the 
 smallest among the remainders r, r', r", etc., then it works 
 equally on the whole series of concepts blended with it so that 
 a vague total impression of all comes into consciousness. The 
 reason for this is explained in sections 27 and 12. The re- 
 mainders are not different parts severed from one and the same 
 concept; hence if a little of the latter is in consciousness, we 
 must not first question whether this little may be one and per- 
 haps quite the smallest among those remainders, but we must 
 assume that it really is so, although at the same time it may be 
 a part of every other greater remainder. If the active concept 
 gradually rises into consciousness, then the remainders, from 
 the smaller to the greater, one after the other, gain a special 
 law of action. By this the above vague impression of the 
 whole rises, in which lies a whole series of concepts, and 
 these are gradually developed out of one another. 
 
 NOTE. Here, among others, must be compared the phenomena 
 resulting from exercise and skill; that, moreover, not every course 
 of thought repeats faithfully the series constructed; and upon that 
 is based, in part, the ground of the inequalities in the quantities II 
 and p (25), with whose possible difference we can not deal further 
 here. Additional facts may be deduced from the following. 
 
 32. If free-rising concepts (of which mention was made in 
 the closing remarks of the last chapter) should blend in regular
 
 4 o8 JOHANN FRIEDRICH HERBART 
 
 gradation, they would be subject to other laws of reproduction 
 which originate out of the blending, and are distinguished and 
 determined according to their differences. Upon occasion, like- 
 wise arises a process of construction and formation of series 
 which differ from the form of analogous concepts in case the 
 latter are given and then sink out of consciousness. From this 
 may be explained the conflict between things as we perceive 
 them and as we think them, as well as the tendency to regard 
 them otherwise than as they first present themselves; conse- 
 quently the modifying action of the self-activity upon that 
 which lies before- the perception. This may be observed espe- 
 cially in the case of children who can have no set purpose in 
 the matter. 
 
 CHAPTER IV. CONCEPTS AS THE SOURCE 
 OF MENTAL STATES 
 
 33. ONE of the objections against mathematical psychology 
 is that mathematics defines only quantity, while psychology 
 must especially consider quality. It is now time to meet this 
 objection, and to collect the explanations of those mental states 
 which the foregoing presents. 
 
 Here we must first remark that the peculiar striving of con- 
 cepts for representation (n) never appears immediately in con- 
 sciousness, for, just so far as concepts change into striving, they 
 are removed out of consciousness. Also, the gradual sinking of 
 concepts can not be perceived. A special instance of this is, 
 that no one is able to observe his own falling asleep. 
 
 So far as it represents or conceives, the soul is called mind; 
 so far as it feels and desires, it is called the heart or disposition 
 (Gemuth.) The disposition of the heart, however, has its source in 
 the mind in other words, feeling and desiring are conditions, 
 and, for the most part, changeable conditions of concepts. The 
 emotions indicate this, while experience, upon the whole, con- 
 firms it: the man feels little of the joys and sorrows of his 
 youth; but what the boy learns correctly, the graybeard still 
 knows. The extent, however, to which a steadfast disposition
 
 A TEXT BOOK IN PSYCHOLOGY 409 
 
 and, above all, character can be given, will be shown later in the 
 explanations of the principles above presented. 
 
 34 < JFirst 4 _there is a blending of concepts not only after the 
 arrest (22), but quite a different one Jbetfojg-.it, provided the 
 degree of opposition (15) be sufficiently small. A principle of 
 aesthetic judgment lies in this. Pleasant feelings in their nar- 
 rowest sense, together with their opposites, must be regarded as 
 analogous to these aesthetic judgments i.e., as springing 
 from the relation of many concepts which do not assert them- 
 selves individually, but rather which perhaps, for psychological 
 reasons, can not be perceived when separated. 
 
 NOTE. In carrying out this investigation, the series of tone 
 relations upon which music depends may be presented as a subject 
 of experiment. Among simple tones, the degree of arrest (the inter- 
 val of tones), entirely alone and without means, determines the 
 aesthetic character of its relation. It is also certain that the psycho- 
 logical explanation (widely different from the acoustical) of all har- 
 mony is to be sought in the difference between the degrees of arrest, 
 and that it must be found there. The necessary calculations for this 
 are, for the most part, to be found in the second volume of the Konigs- 
 berg Archives for Philosophy. Of the somewhat extensive investiga- 
 tions, only the principal ones which experience decidedly confirms 
 can be given here: 
 
 When the forces, into which concepts, through their similarity 
 and their contrasts, separate one another, are equally strong, there 
 arises disharmony. If, however, one of these forces be opposed to 
 the others in such a relation that it is driven to the statical thres- 
 hold (16) by them, then a harmonious relation will prevail. 
 
 35. Second, a principle of contrast is to be found in the com- 
 plexes (22), which we here consider complete. The complexes 
 a+a and b + ft are similar, provided a:a = b:fS; if not, they 
 are dissimilar. Let the degree of arrest between a and b equal p, 
 and that between a and /3 equal IT. Now, if in similar com- 
 plexes, p = TT, then, and then only, will the individual concepts 
 be arrested, exactly as if they had not been in any combina- 
 tion; also no feeling of contrast arises, inasmuch as the arrest is 
 successful only when the opposing forces bring the feeling of
 
 410 JOHANN FRIEDRICH HERBART 
 
 contrast with them ; but, in every variation from the case pre- 
 sented, the less opposed concepts are affected by their com- 
 bination with the other two, but in this very way a part of the 
 arrest will be withheld from the latter; consequently, notwith- 
 standing the opposition, something remains in consciousness 
 that resists, and in this lies the feeling of contrast. If rr</>, 
 then the contrast between a and b will be felt, not that between 
 a and ft. If TT>/>, the case is reversed. When ir = O, the con- 
 trast between a and b is the greatest. 
 
 36. Third, a complex a + a is reproduced by a concept furn- 
 ished by a new act of perception similar to a (26). Now, when 
 a, on account of its combination with a, comes forward, it 
 meets in consciousness a concept opposed to it, ft. Then a will 
 be at the same time, driven forward and held back. In this situa- 
 tion, it is the source of an unpleasant feeling which may give 
 rise to desire, viz., for the object represented by a provided 
 the opposition offered by ft is weaker than the force which 
 a brings with it. 
 
 This is ordinarily the case; desires are excited by a remem- 
 brance of their object. When the remembrance is strengthened 
 by several incidental concepts, the impulses of desire are re- 
 newed. As often as the opposing concepts (i.e., concepts of the 
 hindrances which stand in the way of the longing) attain pre- 
 ponderance, they produce a painful feeling of privation. 
 
 37._Fourth, a concept comes forward into consciousness by 
 its own strength (perhaps reproduced according to the method 
 described in 26), at the same time being called forward by 
 several helping concepts (24). Since each of these helps has its 
 own measure of time in which it acts (according to the formula 
 in 25), then the helps may strengthen one another against a pos- 
 >- sible resistance, but they can not increase their own velocity, 
 y jThe movement in advancing takes place only with that velo- 
 city which is the greatest among several concepts meeting to- 
 gether, but it is favored by all the rest. This favoring is part of the 
 process which takes place in consciousness, but^in no wayjs it 
 anything represented or conceived. Hence it can only be called 
 a feeling without doubt a feeling of pleasure. 

 
 A TEXT BOOK IN PSYCHOLOGY 411 
 
 Here is the source of the cheerful disposition, especially of 
 joy in successful activity. Here belong various movements, 
 instigated from without, which do not accelerate but favor one 
 another as in the case of dancing and music. Of the same char- 
 acter is the action according to several centering motives, and 
 such too is the insight based on understanding several reasons 
 which confirm one another. 
 
 38. In general, it may be observed that feelings and desires 
 have not their source in the process or act of conception in gen- 
 eral, but always in certain particular concepts. Hence there 
 may be at the same time many different feelings and desires, 
 and these may either agree or entirely disagree one with the 
 other. 
 
 CHAPTER V. THE CO-OPERATION OF SEVERAL 
 MASSES OF CONCEPTS OF UNEQUAL STRENGTH 
 
 39. FROM the foregoing, it may, in a way, be perceived that 
 after a considerable number of concepts in all kinds of combina- 
 tions is present, every new act of perception must work as an 
 excitant by which some will be arrested, others called forward 
 and strengthened, progressing series interrupted or set again in 
 motion, and this or that mental state occasioned. These mani- 
 festations must become more complex if, as is usual, the con- 
 cept received by the new act of perception contains in itself a 
 multiplicity or variety, that at the same time enables it to hold 
 its place in several combinations and series, and gives them a 
 fresh impulse which brings them into new relations of opposi- 
 tion or blending with one another. By this, the concepts 
 brought by the new act of perception are assimilated to the 
 older concepts in such a way as to suffer somewhat after the 
 first excitation has worked to the extent of its power, because 
 the old concepts on account of their combinations with one 
 another are much stronger than the new individuals which 
 are added. 
 
 40. If, however, already very strong complexes and blend- 
 ings with many members have been formed, then the same rela-
 
 4 i2 JOHANN FRIEDRICH HERBART 
 
 tion which existed between the old and the new concepts may 
 be repeated within between the old concepts. Weaker concepts, 
 which, according to any kind of law, enter into consciousness, 
 act as excitants upon those masses before mentioned, and are 
 received and appropriated by them (apperceived) just as in the 
 case of a new sense-impression; hence the inner perception is 
 analogous to the outer. Self-consciousness is not the subject of 
 discussion here, although it is very often combined with the 
 above. 
 
 41. In what has been said, lies that which experience con- 
 firms, viz., that the innejLDerception is never a passive appre-^ 
 
 Jhension, JDut always (even against the will) active. The apper- 
 ceived concepts do not continue rising or sinking according to 
 their own laws, but they are interrupted in their movements by 
 the more powerful masses which drive back whatever is op- 
 posed to them although it is inclined to rise; and in the case of 
 that which is similar to them although it is on the point of sink- 
 ing, they take hold of it and blend it with themselves. 
 
 42. It is worth the trouble to indicate how far this difference 
 among concepts which we might be inclined to divide into 
 dead and living may be carried. 
 
 Let us recall the concepts on the statical threshold (16). 
 These are, indeed, in effect nothing less than dead; for, in the 
 condition of arrest in which they stand, they are not able by 
 their own effort to effect anything whatever [toward rising into 
 consciousness]. Nevertheless, through the combination in 
 which they stand, they may be reproduced, and, besides, they 
 will often be driven back in whole heaps and series by those 
 more powerful masses, as when the leaves of a book are turned 
 hurriedly. 
 
 43. If the apperceived concepts or at least some of them 
 are not on the statical threshold, then the apperceiving con- 
 cepts suffer some violence from them; also the latter may be 
 subject to arrest from another side, in which case the inner per- 
 ception is interrupted ; through this, uncertainty and irresolu- 
 tion may be explained. 
 
 The apperceiving mass may be, in its turn apperceived by
 
 A TEXT BOOK IN PSYCHOLOGY 413 
 
 another mass; but for this to occur, there must be present 
 several concept masses of distinctly different degrees of 
 strength. Hence it is somewhat seldom that the inner percep- 
 tion rises to this second power [the apperception of appercep- 
 tion], and only in the case of philosophical ideas is this series 
 considered as one which might be prolonged into infinity. 
 
 CHAPTER VI. A GLANCE OVER THE CONNECTION 
 BETWEEN BODY AND SOUL 
 
 44. UP to the present chapter, concepts have been considered 
 as present in the soul without any question concerning their 
 origin or concerning foreign influences. This has been done for 
 simplicity. Now, sense-perception in part and physiological 
 influences in part, together with concepts already present, must 
 be considered. 
 
 45. Even from experience it may be assumed that each act 
 of perception of any considerable strength requires a short 
 space of time for its creation; but experience and meta- 
 physics at the same time teach that by delaying longer, the 
 strength of the perception in no way increases in proportion to 
 the time, but, the stronger the perception already is, so much the 
 less does it increase, and from this it follows, by an easy calcula- 
 tion, that there is a final limit to its strength which the at- 
 tained concept very soon reaches, and above which even by an 
 infinite delay the same perception will not be able to rise. This 
 is the law of diminishing susceptibility, and the strength of the 
 sense-impression is quite indifferent in regard to this limit. The 
 weakest sense-perception may give the concept quite as much 
 strength as the strongest, only it requires for this a somewhat 
 longer time. 
 
 46. Every human concept really consists of infinitely small 
 elementary apprehensions very unlike one another, which in 
 the different moments of time during the continuance of the 
 act of perception were created little by little. However, if dur- 
 ing the continuance of the perception an arrest caused by old 
 opposed concepts did not occur, these apprehensions would be
 
 4H JOHANN FRIEDRICH HERBART 
 
 all necessarily blended into a single, undivided total force. For 
 this reason the total force will be perceptibly less than the sum 
 of all the elementary apprehensions. 
 
 47. In early childhood a much larger supply of simple sense- 
 concepts is generated than in all the following years. Indeed, 
 the work of the after-years consists in making the greatest 
 possible number of combinations from this supply. Although 
 this susceptibility is never entirely extinguished, yet, if there 
 were not a kind of renewal of it, the age of manhood would be 
 more indifferent and more unfruitful in sense-impressions than 
 it really is. 
 
 Though concepts on the statical threshold are quite without 
 influence for that which goes on in consciousness (16), they can 
 not weaken the susceptibility to new perceptions similar to 
 themselves. Hence this receptivity would be completely re- 
 established if the earlier ratio of arrest were not quite changed 
 by the new acts of perception, and a certain freedom to repro- 
 duce themselves directly given to the older concepts (26). 
 When this happens, the receptivity decreases. The greater the 
 number of old concepts of the same kind present in conscious- 
 ness this means usually the longer one has lived so much 
 greater is the number of concepts which upon a given occasion 
 enter at the same time into consciousness ; and thus with years 
 the renewal of receptivity diminishes. 
 
 48. The above statements refer not only to concepts of 
 exactly the same kind, but to all whose degree of opposition is a 
 fraction. This can not be developed here, since in the foregoing 
 nothing exact could be said of the difference between the degrees 
 of opposition. 
 
 49. It is to be especially observed that the influence of the 
 body upon psychical manifestations is shown in three ways 
 its repression (Druck), its excitation (Resonanz), and its co- 
 operation in action. Upon this are the following preliminary 
 remarks: 
 
 50. Physiological repression arises when the accompanying 
 conditions, which should correspond to the changes in the soul, 
 ran not follow without hindrance; hence the hindrance will also
 
 A TEXT BOOK IN PSYCHOLOGY 415 
 
 be felt as such in the soul because the conditions of each affect 
 both. This repression is often merely a retarding force, to suit 
 which the mental movements must proceed more slowly, as is 
 the case with slow minds that consume time and are stupefied 
 by quick changes. Often, however, repression is similar to an 
 arresting force, and as such it can be mathematically calculated, 
 as when it increases the number of opposed concepts by one or 
 more. By it all active concepts may be driven to the statical 
 threshold; and here we have the explanation of sleep. In this 
 case it would be a deep and complete sleep. 
 
 51. Physiological excitation (Resonanz) arises when the 
 accompanying bodily conditions change more quickly or 
 become stronger than would be necessary to merely cause no 
 hindrance to the mental movements. Then the soul, again in 
 response to the body, will act more quickly and more vigor- 
 ously. The soul must also share the resulting relaxations of the 
 body, as in intoxication and passion. 
 
 52. The co-operation of the soul and body in external action 
 can not originally proceed from the soul, for the will does not 
 know in the least what influence it really exerts upon the nerves 
 and muscles. But in the child exists an organic necessity for 
 movement. At first the soul accompanies this and the active 
 movements arising from it, with its feelings. The feelings, how- 
 ever, become connected with perceptions of the members 
 moved. If, in the result, the concept arising from such a percep- 
 tion acts as a means of arousing desire (16), then the feeling 
 connected with it arises, and to this latter as accompanying 
 bodily condition belong all those phenomena in the nerves and 
 muscles by which organic movement is actually determined or 
 defined. Thus it happens that concepts come to appear as a 
 source of mechanical forces in the outer world.
 
 FRIEDRIGH EDUARD BENEKE 
 
 (1798-1854) 
 
 A TEXTBOOK OF PSYCHOLOGY 
 AS NATURAL SCIENCE 
 
 Translated from the German * by 
 BENJAMIN RAND 
 
 CHAPTER L FUNDAMENTAL PROCESSES OF 
 PSYCHICAL DEVELOPMENT 
 
 22. First fundamental process. Sensations and perceptions 
 are formed in the human soul in consequence of impressions 
 or excitations which come to it from without. The usual 
 view is that we receive the external impressions primarily 
 through the bodily organs, and only thereafter do they pro- 
 ceed to the soul by means of the nerves and of the brain. But 
 of this our self-consciousness, which we have designated ( i) 
 as the only fundamental source for psychological knowledge, 
 gives no hint whatever. The excitation of the bodily organs 
 presents itself to us as an effect concomitant with the formation 
 of the sensory impressions, or as running parallel with it; and 
 we must regard as a false inference if one endeavors in the man- 
 ner indicated to place the same in causal connection therewith. 
 There is no scientific justification ( 47 ff.) for this assumption as 
 it is ordinarily made. Furthermore nothing is in the least gained 
 thereby for the doing away with the offensive dissimilarity be- 
 tween external objects and the soul. For we are still even as 
 little able to conceive how a psychical seeing, hearing, etc., can 
 arise from a material vibration of the nerves, or of the brain, as 
 how the soul itself can be immediately excited by external im- 
 pressions into the formations of sensations. Let anatomy and 
 
 * From F. E. Beneke's Lehrbuch der Psychologic als N aturwissenschafl. 
 Berlin, 1833; bearb. von J. G. Dressier, 4 Aufl. ib., 1877.
 
 PSYCHOLOGY AS NATURAL SCIENCE 417 
 
 physiology, therefore, explain and establish the results of 
 observation in their domain. In psychology we hold firmly to 
 the fact that our self-consciousness says nothing about any 
 such mediation. 
 
 23. The creation of sensations and perceptions necessarily 
 presupposes: (i) certain external elements (excitations, impres- 
 sions) which are received and appropriated by our soul; and (2) 
 certain inner forces, or faculties, by which it receives and ap- 
 propriates these elements. These forces, which, like the excita- 
 tions aforesaid, show themselves at the first glance to be mani- 
 fold, or to form several characteristic systems, we style sensory 
 faculties, just because they respond to external excitations; and, 
 furthermore, we call them original faculties (Urvermogen) 
 of the soul, in so far as we are unable to derive them from any- 
 thing else. It is to be observed, however, that the sensory 
 excitations so soon as they are received and appropriated are 
 transformed likewise into psychical elements. We attribute to 
 the sensory faculties in respect to this process a higher or 
 lesser degree of sensitiveness to excitation. By means of this 
 variable degree the extent of the excitation received, or the 
 vividness of the sensation, is shown to be conditioned from 
 within. 
 
 24. Second fundamental process. The human soul is con- 
 stantly acquiring original faculties. Of this innermost life-pro- 
 cess, by which alone the soul is able to continue its life, we ob- 
 tain knowledge only from the fact, that from time to time the 
 original faculties become exhausted. There is in other words an 
 inability to form sensory perceptions, or to carry on activities, 
 which demand new and original faculties, and these remain for 
 a subsequent more or less extended use. As an explanation of 
 this phenomenon the effect indicated proves to be the most 
 plausible hypothesis. We cannot, indeed, determine more ex- 
 actly the nature of this process, not merely because it wholly 
 escapes consciousness, but also because among all other pro- 
 cesses of which we are conscious there is none analogous to it. 
 An indication of the circumstances under which this process 
 occurs, and occurs more perfectly, we reserve for later consider-
 
 4 i8 FRIEDRICH EDUARD BENEKE 
 
 ation ( 335) on account of this very obscurity, and in order 
 to make use in fuller measure of the results of observation. 
 
 25. The original faculties are essentially volitions so long 
 and so far as they have not as yet adopted excitation for their 
 completion ; that is to say, they strive for this fulfilment as for 
 a complement intended for them by their nature. We also 
 term this striving " tension." This character appears especially 
 in the uneasiness which develops if they have accumulated 
 unused in rather a large number. This is an uneasiness which as 
 experience shows can mount to any conceivable degree, and can 
 lead even to despair of life and to suicide. Moreover, the use of 
 the original faculties is by no means restricted to the formation 
 of sensations and perceptions. On the contrary, attaching them- 
 selves to inner formations they become effective for the same 
 excitations and for achievements of the most varied sort. Es- 
 pecially do they form in this way the fundamental active prin- 
 ciple in all action as well as in all psychical products. 
 
 26. Third fundamental process. The combination of facul- 
 ties and excitations, such as are originally grounded in sensa- 
 tions and perceptions, and maintained in their reproductions, 
 reveals sometimes a firmer and sometimes a less firm inter- 
 penetration of these two classes of elements. A more accurate 
 observation now teaches us, that when elements are less firmly 
 united and therefore mobile, they can be transferred in the 
 greatest variety of combinations from one psychical formation 
 to another. In all psychical developments at every moment of 
 our lives there is an active striving towards a balancing or 
 equalizing of the mobile elements in them. In a preliminary 
 way we may give as examples of this fact the increase of in- 
 tensity, which all the operations of our mind experience through 
 the emotions of joy, of enthusiasm, of love, of anger, etc.; as 
 well as upon the other hand, the depressions of the same, 
 through sorrow, fear, etc. 
 
 27. Our self-consciousness constantly exhibits a change, 
 which sometimes mounts to an appalling variety and rapidity. 
 But this change does not extend so far as at first glance it 
 appears to do, and moreover chiefly effects only the excited
 
 PSYCHOLOGY AS NATURAL SCIENCE 419 
 
 state. For every psychical product that thus became formed in 
 the human soul with any degree of perfection persists, even 
 after it has disappeared from consciousness or from the sphere 
 of excited psychical development, in the unconscious or inner 
 being of the soul, out of which it can later enter into the con- 
 scious psychical development or be reproduced. We term that 
 which persists in an unconscious state, with reference to the 
 psychical development which continues unconsciously to exist, 
 "a trace"; and in reference to those developments which are 
 either constructed upon this basis, or which proceed therefrom, 
 " a rudiment." (There is prefigured or predisposed in the same 
 a presentation of imagination, a sensation, etc.) Every such 
 trace consists therefore of two elements: faculty and excitation. 
 28. We know indeed these traces or rudiments only by 
 means of the reproductions thereof. We are, nevertheless, per- 
 fectly certain of them, because of the fact that these reproduc- 
 tions, where no hindrance occurs, always take place not only 
 qualitatively, but also quantitatively, in the strictest agree- 
 ment with the earlier psychical formations. The kind of the 
 excitation and the strength of the faculty (the two elements out 
 of which every trace was formed) return to consciousness in the 
 same way, as at their coalescence they conditioned the devel- 
 opment of the trace. In fact, strictly speaking, even this per- 
 sistence of the trace needs no explanation, since there is repre- 
 sented in it only the universally evident fact, that what has 
 once come into existence continues until it is destroyed through 
 the agency of special causes. What, therefore, is here subject 
 to explanation is not the continued subsistence, but only the 
 transition into unconsciousness of what previously had been 
 conscious; and this is easily comprehended from the aforesaid 
 process of balancing. Inasmuch as the conscious developments 
 balance or transfer in every direction, so far as an immediate 
 combination takes place, those elements which are not firmly 
 appropriated by them and are mobile, it follows, that such a 
 depression must take place in them that they become uncon- 
 scious forms or mere traces ( 30) . 
 , 29. In reference to the presentation of these traces, which,
 
 420 FRIEDRICH EDUARD BENEKE 
 
 as they are essentially unconscious cannot be made immedi- 
 ately by means of these themselves, we must hold absolutely to 
 the effects which have led to their assumption. These traces 
 hence have no actual place of existence. As is the soul in 
 general, so also all its parts are nowhere; for self consciousness, 
 which is our single source of knowledge, contains with itself 
 immediately, and by itself, (without the addition of perceptions 
 of the external senses), nothing, whatever of spatial relations. 
 The traces are also united to no bodily organ. For the intuitive 
 notions of space, and the transformations thereof, which run 
 parallel to the psychical developments, are in the strictest 
 sense merely parallel to them, that is to say, synchronous, or at 
 best always synchronous. They can thus in no wise be made 
 essential to them , to say nothing of being postulated as their 
 substantial basis (43 ff.). The trace is what comes between 
 the production of a psychical activity, (e.g., a sensory percep- 
 tion), and its reproduction, (e.g., as recollection). Since both of 
 these acts are psychical we may also conceive of the trace only 
 in psychical form. We are, nevertheless, in general able to 
 acquire very definite ideas of it, since the fundamental condi- 
 tions for this conception are given us in any case on two sides, 
 and not infrequently, (when there traces are manifoldly repro- 
 duced), on several sides. 
 
 30. Faculties and excitations exist in the traces in the rela- 
 tively constant combination, which they have entered into with 
 one another ( 26). Since nothing can escape from the faculties, 
 the loss by which the previously conscious or aroused develop- 
 ments become mere traces, must effect the received excitations; 
 and so far as this loss occurs, to that extent is the faculty filled 
 by them again emptied or free. In so far all traces are as such 
 volitions (Strebungen) ; that is to say, the original faculties 
 given in them strive for the recovery of that which they have 
 lost, or for the renewed attainment of consciousness. 
 
 31. The certainty, which we receive by a strict comparison 
 of facts concerning this inner persistence, is, likewise, in two 
 respects, invaluable for the perfecting of general psychological 
 knowledge. First, because we apply them in a progressive
 
 421 
 
 direction. Since all previous developments of the soul, so far as 
 they have not again been destroyed, continue to exist in the 
 inner being of the soul, it follows, that this must, or (what is the 
 same thing) the forces or faculties of the soul must, consist of 
 traces of the earlier aroused developments. We can, therefore, 
 perceive these faculties not merely from their effects, (which 
 lead only to a summary or rough determination), but likewise 
 from their causes too, or from the conscious developments pre- 
 ceding them. Since now these latter separate in far greater 
 extension and far more decidedly, (in hundreds of cases and 
 more) , we thus derive by this means for the perception of their 
 nature and organisation the same advantages as those which 
 magnifying glasses afford when applied to external nature. 
 Secondly, we can furthermore turn to account the doctrine of 
 inner persistence in a retrogressive construction. This matter 
 has been provisionally discussed (21). If we have clearly re- 
 cognised in a certain series of developments the manner in which 
 the traces are formed, we can thus disregard that which is 
 added to these in our thoughts, and, since we continually repeat 
 this, can at last attain to a knowledge of the original nature of 
 the soul. 
 
 32. How far this persistence extends in reference to the 
 quality of the developments, and the length of time, can 
 scarcely be established with perfect certitude from the fore- 
 going experiences. We know of the inner persistence only 
 through the reproductions ( 28). But from the fact that 
 something has not heretofore been reproduced, and even now 
 cannot be reproduced, it does not immediately follow that the 
 same is not yet present, nor even that it is not capable of repro- 
 duction. Experiments which have been made in this matter in 
 violent fevers and injuries, etc., have shown, that what one has 
 believed to have long disappeared, because it has never been 
 reproduced under the ordinary conditions of reproduction, was 
 raised into consciousness and psychical activity under unusual 
 conditions of production. The presumption, therefore, is great, 
 that in general whatever has once formed a part with any degree 
 of completeness of our soul is never again lost.
 
 422 FRIEDRICH EDUARD BENEKE 
 
 33. Since the persistence of the traces consists in nothing 
 except the continuance of whatever has once attained exist- 
 ence, the perfection in general of the traces must also be 
 dependent upon the perfection with which the developments 
 have originally been formed. In the sensations and perceptions, 
 therefore, it would depend upon the perfection with which the 
 excitations have been appropriated. We ascribe to the sensory 
 original faculties in this connection a higher or lower degree of 
 strength. 
 
 34. In the innermost soul traces remain of this transference 
 of mobile elements from one psychical form to another, and 
 thereby are established, in the same manner as all permanent 
 combinations, even the combinations of incompatible forma- 
 tions into groups and series: the combinations between the qual- 
 ities of a thing, between the spatial and temporal coincidence, 
 and the connection between causes and effects. These are, there- 
 fore, by no means to be regarded merely as ideal relations, but 
 to be viewed, just as much as the single presentation, as some 
 real abiding existence in the inner being of the soul. 
 
 35. Fourth fundamental process. Identical formations of 
 the human soul, and similar ones according to the measure of 
 their likeness, attract one another, or strive to enter into closer 
 relations with each other. This presents itself to our observa- 
 tion so frequently, not merely in its products but also in its 
 occurrence, that it needs no further explanation. Familiar 
 examples are such as, the witty combination of ideas, the forma- 
 tion of similies and judgments, the fusion of similar feelings 
 and endeavors, etc. If now in these examples the coalescing 
 formations are only partly similar to one another, this attrac- 
 tion, as is confirmed in the most evident manner by a stricter 
 analysis of the facts in various cases, must take place between 
 formations which are totally similar with still greater strength, 
 and decisiveness. Nevertheless, the more critical observation 
 shows that in all these attractions only a coalition of similar 
 formations, but still no permanent combination or fusion of 
 them is affected. Rather the process of balancing must enter 
 in_a complementary way for these latter, just as it must enter
 
 PSYCHOLOGY AS NATURAL SCIENCE 423 
 
 in permanent combinations between dissimilar, formations. 
 This balancing process reveals itself as active here with most 
 remarkable strength, so that the blending gains a higher degree 
 of intimacy, since a specially favorable basis is prepared for it 
 by the indicated attraction (91). 
 
 36. The process of formation is of exceptional importance, 
 especially for the judgment of quantitative development. If we 
 suppose one and the same sensation, presentation, desire, etc., 
 to be frequently produced, the traces remaining therefrom 
 enter not only into relation with one another, but they also 
 coalesce owing to their complete similarity into one total form- 
 ation. And such formation appears to us as one to that degree 
 in which we cannot become at all aware immediately of its com- 
 plexity (qualitative), but only by means of its augmentation 
 (quantitative). The strict conception and application of this 
 will lead us to a number of highly significant conclusions, which 
 have heretofore escaped the notice of science, because it has 
 only very inaccurately taken these results into account. 
 
 37. All the processes explained in the preceding paragraphs 
 are of such an elementary character, and of so great universal- 
 ity, that scarcely one even of the simplest developments of our 
 matured soul could be pointed out, in which they do not alto- 
 gether, and even repeatedly, collaborate. But they show them- 
 selves active in very different relations of combinations and 
 degree; and thus there is indeed nothing that prevents one 
 from indicating this or that single fundamental process as the 
 conditioning cause for this or that effect, when its agency is 
 particularly conspicuous above the others. A more exact 
 observation teaches, that these processes can occur with very 
 various degrees of rapidity and vivacity. And since these 
 processes, (at least so far as there is no external condition), 
 manifest themselves uniformly in all developments, which take 
 place in a human being within the range of a certain funda- 
 mental system, we are justified in deriving them in so far from 
 the original faculties, and in attributing to the latter in respect 
 thereof a higher or lower degree of animation as a pri- 
 mordial quality.
 
 424 FRIEDRICH EDUARD BENEKE 
 
 CHAPTER 1 L THE FUNDAMENTAL NATURE OF 
 THE HUMAN SOUL 
 
 38. If we summarize first of all the most general character- 
 istics concerning the nature of the human soul which result 
 from our preceding exposition, it presents itself to us: (i) as a 
 perfectly immaterial being ( 22 and 29), consisting of certain 
 fundamental systems, which not only in themselves, but also 
 in combination with each other, are most intimately one, or 
 constitute one being ( 26) ; (2) as a sensory being, i.e., the ele- 
 mentary forces of the soul are capable of certain stimulations 
 from without by excitations, which are assimilated and retained 
 by these forces ( 22 f.). To these must still be added: (3) the 
 forces of the soul gain by this assimilation a more positive 
 organisation, and in this they enter upon manifold closer com- 
 binations with one another, partly by means of the fusion of 
 similar forms into one total form ( 35 f.), and partly by means 
 of the combination of dissimilar forms into groups and series 
 (34). (4) But the forces and faculties of the soul have also an 
 original determinateness, which is twofold: the original de- 
 terminateness of the fundamental systems to which they be- 
 long, and the original determinateness of certain degrees of 
 strength ( 33), and vivacity ( 37), and sensitiveness of 
 stimulus ( 23). Observation teaches us that every degree 
 of any one of these fundamental conditions can occur together 
 with any degree of the others. 
 
 39. For a more exact determinateness we must compare 
 human souls with the souls of lower animals. If we compare 
 that which appears in the latter as the effect of the psychical, 
 with that immediately perceived in us and the effects thereof, 
 the most striking characteristic of human souls appears to be, 
 that they are spiritual, (that is to say, if for the present we 
 formulate this superiority in its greatest universality and as it 
 immediately appears), souls, which are capable of a clearer, 
 more definite, and more comprehensive consciousness, and 
 which necessarily develop such consciousness up to a certain 
 point of time, although some in greater, others in lesser perfec-
 
 PSYCHOLOGY AS NATURAL SCIENCE 425 
 
 tion. The question now arises, what we have to regard as that 
 which fundamentally conditions this superiority. 
 
 40. We here first encounter a view which was especially in 
 the last century, and even in our time has been again, pro- 
 pounded. According to it, the original forces of human souls are 
 said to be in and of themselves entirely similar to those of the 
 lower animals, and the spiritual character of the human soul is 
 derived solely from the more excellent bodily organisation with 
 which this is united. In support of this view three things have 
 been especially emphasized: first, the possession of hands by 
 which man is enabled to change the position and form of ob- 
 jects, and thus become acquainted with an incomparably 
 greater number of these qualities; secondly, the possession of 
 speech, which makes possible a manifold expression of acquired 
 ideas, etc., as well as a more extended and more perfect reten- 
 tion of them; and, thirdly, the slower growth owing to a longer 
 period of childhood, in consequence of which there is a more 
 varied accumulation and elaboration of ideas. 
 
 41. The reasons specified in the preceding paragraph con- 
 cerning the spiritual character of the human soul in no wise give 
 a perfectly satisfactory explanation. From the greater mass of 
 heterogeneous ideas which are acquired through the medium 
 of the hands and speech, there would result in and for itself 
 only a greater throng of them, and as a consequence rather a 
 more rapid and more complete obliteration of the single idea. 
 It is just as difficult to perceive from the slower growth of the 
 body how it should transform the unspiritual into something 
 spiritual without the addition of another positive factor. 
 We have on the contrary to regard the slower formations of 
 the body not as a cause, but as a consequence of spiritual devel- 
 opment, which constantly exerts a certain modification upon 
 the bodily development. The higher perfection of the human 
 soul, therefore, cannot be in such wise merely externally condi- 
 tioned, but must be a perfection that is internally and qualita- 
 tively conditioned, and which affects the innermost nature of 
 the psychical original faculties themselves. 
 
 42. Of the three fundamental characteristics of the original
 
 426 FRIEDRICH EDUARD BENEKE 
 
 faculties as designated ( 38), the susceptibility of excitation 
 occurs not merely in many of the lower animals in like perfec- 
 tion with man, but also in case of some of them in greater per- 
 fection than in man. Vivacity occurs with men as with the 
 lower animals in very many degrees. But what is peculiar and 
 essential to human souls is a higher power of susceptibility and 
 of appropriation of the excitation, as well as a greater force of 
 inner persistence of the developments founded thereupon. 
 By means of this more perfect inner persistence, there is made 
 possible in the psychical developments of men an infinite in- 
 crease of strength, of clearness, and of capacity of coalescence. 
 In combination therewith, but also only in combination there- 
 with, the hands, the speech, and the longer period of childhood 
 are, to be sure, of no little significance for the development of 
 'the human soul. We can best designate this superiority of man 
 over the lower animals by ascribing to the former a spiritual 
 sensuousness. Besides the superiority of the higher energy of 
 the original faculties there is another in which the possession of 
 speech and hands are ranked only as single constituents. This 
 is the more individual and more definite determinateness, and 
 in consequence of that, the more definite separation of the 
 different elementary systems, both as to the qualities of the 
 several susceptibilities and activities, and as to the combi- 
 nations and interweavings. 
 
 CHAPTER III. THE RELATION OF THE SOUL 
 AND THE BODY 
 
 43. THERE is still need of a more exact determination con- 
 cerning the relation of the soul to the body. We have already 
 remarked ( i), that these are very definitely separated in the 
 perception (Auffassung), and the knowledge based thereupon; 
 since to the knowledge of the soul everything belongs that we 
 perceive by means of self-consciousness, and to the knowledge 
 of the body everything by means of the external senses. We 
 must leave to metaphysics the deeper determination of their 
 real relation. We have here only to do with the question,
 
 PSYCHOLOGY AS NATURAL SCIENCE 427 
 
 how they must stand to one another for the purposes of psy- 
 chology. 
 
 44. Transferring the contrary kinds of knowledge men- 
 tioned in the foregoing paragraphs to the real, without due 
 consideration those who have set as their task a strictly philo- 
 sophical knowledge, in most cases have represented the soul 
 and the body as being in their innermost nature opposed to one 
 another. And from this the most remarkable hypotheses have 
 been evolved ; since upon the other hand the experience of every 
 moment presents their immediate union in one and the same 
 being, and also their immediate interaction and co-operation. 
 
 45. When on the contrary there was set as a task no deeper 
 philosophical knowledge, but there was in mind only the prac- 
 tical application, which a synthesis of both rendered desir- 
 able for a common knowledge, it has been attempted in most 
 cases to refer the psychical developments to the bodily; indeed, 
 some have gone so far as quite generally to designate the former 
 as mere products of the bodily organization peculiar to man. 
 This is the fundamental view of materialism. But the history of 
 psychology shows, that never at any time has it been possible, 
 either to explain or to construct from the material the very 
 least of the developments of the soul. And not only so, but it 
 can also admit of no doubt, that this will be just as little pos- 
 sible in the entire future. Both kind of ideas are much too dis- 
 similar for this. In whatever way we may determine and 
 combine the material forms and processes, we never attain to 
 anything that has even the remotest resemblance to a thought, 
 or to any other psychical product. 
 
 46. What has given rise to the materialistic view indicated 
 in the preceding paragraph is only the greater distinctness and 
 definiteness, which the presentations of the bodily have over 
 those of the psychical for those unused to self-examination. 
 But this advantage is nevertheless purely subjectively 
 grounded (in the nature of the presentation) ; and the transfer- 
 ence of it to the objective, or real, can be in no wise justified. 
 And as a subjective advantage it is to be regarded not even as 
 essentially necessary, but only as accidental and temporary;
 
 428 FRIEDRICH EDUARD BENEKE 
 
 since in a practice continued for some time and intelligently 
 conducted, an equally great, indeed a still greater, clearness 
 and defmiteness can be gained for the perception of psychical 
 products and results. 
 
 47. To this must be added, that we are able to observe 
 ( 13) the developments of our soul far more immediately and 
 more intimately. This, in connection with what has been 
 remarked in the preceding paragraph, enables us to develop the 
 knowledge of the psychical forms and processes to such great 
 definiteness, exactness, and acuteness, that the knowledge of 
 the bodily stands far in the background. Indeed, we can foresee 
 with the highest probability, that a completeness of under- 
 standing and construction for the bodily, such as we already 
 have for the psychical, can never be gained (granted the 
 highest possible perfection of magnifying glasses, etc.) even 
 approximately. Even regardless of reasons of inner truth, it 
 appears from the standpoint of the products of knowledge it- 
 self as far more desirable, that, in direct opposition to the 
 materialistic view, we should be able to conceive and to 
 construct the bodily according to the forms and the laws of 
 the psychical. 
 
 48. The problem which presents itself ( 44) in the appar- 
 ently opposed fundamental natures of the soul and body can be 
 solved after deeper reflection (Aufassung) very simply, in that, 
 we also perceive our own body, as everything else corporeal, 
 only by means of the impressions upon our senses, and, there- 
 fore, not immediately as in the case of the soul, where the 
 powers and developments are apprehended as they are in them- 
 selves. But there correspond certain forces to the perceptions 
 of our own body as its being (in itself) , which as they effect those 
 sensory perceptions, permit still many other results to proceed 
 from themselves. And the opposition in our observations of the 
 two kinds of developments can arise just as well from the differ- 
 ence in the faculties of perception, as from the difference of the 
 perceived objects and events. That this difference is not so 
 great as it appears is already in the highest degree probable, 
 even (we can truly say) certain, from the fact, that there exists
 
 PSYCHOLOGY AS NATURAL SCIENCE 429 
 
 no kind of bodily developments which cannot become con- 
 scious under certain circumstances, and which as conscious can- 
 not be immediately perceived by us. But in that event it be- 
 comes psychical ( i and 43) ; as it stands also in fact in this 
 case to the positively psychical developments entirely in the 
 same relations of reciprocal aid, of combination, and of opposi- 
 tion, as the psychical developments stand to one another. 
 Such a transformation of a thing most ordinarily to be con- 
 ceived as non-psychical into one to be conceived as psychical, 
 would be unthinkable, if in their fundamental nature they 
 were opposed. 
 
 On the contrary we are led to conclude that both kinds of 
 forces must stand very close to one another in their innermost 
 nature ; and no artificial hypotheses ( 44) are necessary for the 
 explanation of their intimate relationship and reciprocal action. 
 What through the senses we learn of the human body, or what 
 we commonly term the body, we have to view only as external 
 signs or representatives of the innermost nature of the body, 
 which, like the soul, consists of certain forces and their develop- 
 ments, that are indeed distinct from those of the soul, but are 
 nevertheless essentially of the same kind. 
 
 49. On the other hand, it must be added, that the different 
 fundamental systems of the soul also do not develop con- 
 sciousness in equal perfection, but rather in very significant 
 gradations. And they show the gradations in all relations 
 parallel, as we observe between the positively psychical 
 developments and the bodily developments raised to the 
 psychical. Thus the difference between the soul and the 
 body stands forth still more definitely than a mere difference 
 of degree. They even approach so near to one another that no 
 real line of separation can be drawn between them in the living 
 man, and in general they are not farther separated than the dif- 
 ferent psychical fundamental systems from one another. A 
 real separation between soul and body takes place first only at 
 death. 
 
 50. In any event we are justified according to the conclu- 
 sions reached, to include the bodily, so far as it develops
 
 430 FRIEDRICH EDUARD BENEKE 
 
 consciousness, in our science, and to make the attempt to dis- 
 cover whether its developments, and especially its action upon 
 the soul, may not be construed according to the laws, which 
 have come to light for the positive psychical developments from 
 the facts observed by our self-consciousness. It furthermore 
 immediately appears from this, that we have throughout to 
 suppose no other bond for the connection of soul and body, than 
 that by which the psychical systems themselves are united. 
 
 51. Even the most general survey of the bodily develop- 
 ments permits no doubt concerning the fact, that the four fund- 
 amental laws which have been established for the psychical, 
 likewise have their application as determining and regulating 
 the bodily, though to be sure with some modifications. The 
 bodily forces also need support from without, and they strive 
 after and appropriate it; and in them, too, life is propagated 
 from within by means of continual acquisition of new homo- 
 geneous faculties or forces. In them also, received stimuli are 
 balanced with reference to the formations which stand in rela- 
 tion therewith ; and the developments deprived in this way of 
 excitation continue to exist in the forms of traces or forces, 
 which thereafter enter as rudiments into future developments. 
 Finally, in them too, a reciprocal attraction between homo- 
 geneous developments manifests itself. They enter into closer 
 relation, or even totally fuse with each other. As a result of all 
 this there is formed that which one terms (favorably or unfav- 
 orably etc.) the bodily constitution. What is lacking to the 
 bodily developments in all these relations, is only a more inde- 
 pendent development of elementary acts and forces, which 
 distinguish psychical development ( 42). They coalesce too 
 with less regard to distinctions; and the forms of organisation 
 have therefore no such definite determination (47). 
 
 52. It is thus obvious, that the recognised fundamental 
 laws prove effective for the interaction between soul and body, 
 and the rudiments remaining from these. Here only the adjust- 
 ment of the mobile elements and the attraction of the homo- 
 geneous formations come into consideration. By means of the 
 former all transferences and influences which proceed from the
 
 PSYCHOLOGY AS NATURAL SCIENCE 431 
 
 soul to the body, or from the body to the soul, are determined : 
 especially in the first direction every bodily doing or action 
 produced by the soul, as well as the involuntary manifestations 
 of the emotions, etc. ; and in the second direction the manifold 
 aids which the psychical development experiences from the 
 bodily, and by means of which the soul as it were constantly 
 feeds upon the bodily. The attraction in relation to those things 
 homogeneous, shows itself operative especially in the distribu- 
 tion of the tones from the one to the other, and in the associa- 
 tions between similarly toned psychical and bodily develop- 
 ments. Moreover, these are operative in various forms, e.g., in 
 passions and other emotions, for the production of balancings 
 among the corresponding bodily developments, when psychical 
 developments meet, which by their firmer forms of organiza- 
 tion, or otherwise, are prevented from balancing. Thus blushing 
 accompanies shame and anger, etc.; tears of emotion accom- 
 pany the unexpected proofs of love, and deserved but long with- 
 held marks of distinction, etc. From all this it follows, that we 
 have to conceive the bodily life as subordinated to the psychi- 
 cal; whereas materialism affirms that the life of the soul is only 
 an intensified bodily; and that as an independent existence in 
 man there is no soul.
 
 MORITZ WILHELM DROBISGH 
 
 (1802-1896) 
 
 EMPIRICAL PSYCHOLOGY ACCORDING TO 
 THE METHODS OF NATURAL SCIENCE 
 
 Translated from the German* by 
 BENJAMIN RAND 
 
 FIFTH SECTION: THE FUNDAMENTAL EX- 
 PLANATION OF THE PSYCHICAL LIFE 
 
 III. THE DYNAMICS OF IDEAS AS A PRINCIPLE 
 OF EXPLANATION OF PSYCHICAL PHENOMENA 
 
 138. TEE INTERDEPENDENCE OF PSYCHICAL 
 PHENOMENA 
 
 IN the explanation of psychical phenomena it is most neces- 
 sary, that their connection and interdependence be not ne- 
 glected in the consideration of their diversity, because other- 
 wise we should set up unavoidable hindrances to any theory 
 seeking for unity. Of this character is particularly the assump- 
 tion of an original two- or threefold division of the activity of 
 the mind, which is supposed to rest upon the qualitative differ- 
 ence of inner phenomena. After the detailed examination of 
 the latter we should still find impossible to place in one and the 
 same category as regards their origin, ideas, feelings, and de- 
 sires; on the contrary, we must rather regard the lack of inde- 
 pendence, and even actual dependence of the forms of the latter 
 two kinds of phenomena upon the ideas, as an indication that 
 these in some way lie at their foundation, and that they are 
 capable of being made comprehensible as derived states. In- 
 
 * From M. W. Drobisch's Empirische Psychologic nach nalurwissenschafticher 
 Methode, Hamburg und Leipzig, 1842; 2te Aufl. 1898.
 
 EMPIRICAL PSYCHOLOGY 433 
 
 deed, so many earlier psychologists have sought to prove this, 
 that we may say the atomistic trichotomy of the soul was first 
 introduced by Kant and his school. 
 
 If now the uselessness of abstract powers of the mind has been 
 made clear in what has preceded, no one can desire to revert, 
 either to a general faculty of ideas, or to any specific kinds of 
 it, under the names of sense, imagination, understanding, etc. 
 On the contrary, the ever increasing specialisation of these fac- 
 ulties, which becomes necessary if one somewhat more than 
 superficially considers inner experience, shows that we cannot 
 pursue this method with success, but have to take one directly 
 opposed. This consists in supposing each single idea itself as an 
 independent state of the mind, and accordingly an indefinitely 
 large number of such states. If now to each one of these a 
 power is ascribed as cause, we thus acquire, to be sure, instead 
 of a moderate number of faculties of the mind, an almost un- 
 limited number of individual powers of the mind. We do not 
 fail to perceive that we are thereby still further, and in a far 
 more hazardous way, removed from the unity of the soul, than 
 is the case with the theory of faculties. But if we do not suc- 
 ceed in comprehending the unity of ten or twenty faculties, the 
 failure consequently is essentially not greater if a thousand or 
 ten thousand powers of forming ideas appear hard to combine. 
 Nevertheless this would only be a lamentable consolation, 
 which we are far from claiming. Therefore, either we must seek 
 so to justify that hypothesis, that it no longer controverts the 
 unity of the soul, or this principle is not adequately estab- 
 lished, and must be given up. Let us then first test somewhat 
 more closely this demand for the unity of the soul, as the pos- 
 sessor of the powers of the mind. 
 
 139. THE UNITY OF THE SOUL 
 
 If it must be conceded that the powers of the mind, as causes 
 of its states, are not objects of inner observation, it holds still 
 more true of the mind itself, as the possessor of those powers. 
 For self-consciousness by no means reveals to us the mind, on
 
 434 MORITZ WILHELM DROBISCH 
 
 the contrary, shows only the empirical I, from which through 
 abstraction of its changing content the pure I is first at- 
 tained; but which, for that very reason, is an empty and really 
 formal idea. The identity of our psychical being is, therefore, 
 by no means immediately guaranteed as a fact by the identity 
 of our self -consciousness, and it is merely upon inferences that 
 this conviction is based. Without deeper metaphysical argu- 
 mentation the following observations can be made upon this 
 subject. 
 
 All our ideas have a tendency to become united, to exchange 
 their multiplicity for unity, and they actually coalesce, so far as 
 the contradictions of their contents do not prevent. Our sensu- 
 ous perception, as well as our intellectual conception, is a con- 
 stant process of unification, either through the percept, or the 
 concept; therefore, every theoretical science involves the effort 
 to reduce the principles of explanation to the lowest possible 
 number. The fact, that only a few ideas can enter our conscious- 
 ness at once, shows to be sure at first glance, that they displace, 
 suppress, therefore, as it were, expel one another; but also on 
 the other hand, that they are not able to avoid one another, but 
 are held together by an attractive force. The same thing like- 
 wise appears in associations, these quite involuntary and art- 
 less combinations of simultaneous ideas. It is, therefore, pos- 
 sible to attribute similar attractive and repellant forces to ideas, 
 after the analogy of the physical-chemical hypothesis of attrac- 
 tions and repulsions of elements. But leaving out of considera- 
 tion the fact, that here attraction and repulsion must be ascribed 
 simultaneously to the same elements of psychical life, which 
 beyond controversy is inconceivable (the physicist attributes 
 attraction to the molecules, and transfers repulsion to the sur- 
 rounding sphere of heat), there is furthermore this difference, 
 that the elements of bodies have an independent existence, so 
 that the existence of the body depends upon that of its ele- 
 ments, which become thereby the constituents out of which it 
 is composed. 
 
 Nevertheless, it will not occur to anyone to affirm that the 
 mind is composed of its ideas, and that these have also
 
 EMPIRICAL PSYCHOLOGY 435 
 
 existence apart from the mind. The mind, in which they are, 
 and because they are in it, which has no constituents (for what 
 apart from ideas, could otherwise be its constituents?), and is 
 consequently simple, must moreover itself be assumed to be 
 the principle of unity. This also leads to the same conclusion, 
 that the body is external to the mind, but ideas, feelings, and 
 desires, are within it. The mind is, therefore, in a middle 
 ground between outer and inner experience, as the unit of mea- 
 sure belonging to no experience of things and states of 
 the external and internal world. With a measure one can in- 
 deed measure ; but one cannot wish to measure it itself, or it 
 ceases to be a measure. One can indeed distinguish the parts in 
 it; but these are only accidental parts, and not essential con- 
 stituents. 
 
 140. THE REFUTATION OF THE FACULTY 
 CONCEPT 
 
 If accordingly the hypothesis of the unity of the soul appear 
 to us reasonably established, so that we have to think of it as 
 having strict simplicity of being, because otherwise a new prin- 
 ciple of unification would be needed, the question is all the 
 more seriously renewed, how the other hypothesis of an un- 
 limited number of states of the mind is supposed to be com- 
 patible with it. There corresponds to every individual sensa- 
 tion a simple idea as a state of the mind, and combined ideas 
 originate from these as their elements. Shall we endow the 
 mind with as many faculties as it has simple ideas? And if not, 
 what else shall we do? In order to decide this question, it is ne- 
 cessary first to determine, what must be understood by facul- 
 ties. If we oppose activity to it, as reality to possibility, the 
 entire concept of faculty is at bottom an empty thought, which 
 can signify nothing other, than that after an activity has origin- 
 ated we can then add in thought, that nevertheless the possi- 
 bility must have been present for it beforehand. But this possi- 
 bilty is also only a mode of forming ideas in the mind of the 
 thinker, and is nothing in the things themselves; for we should
 
 436 MORITZ WILHELM DROBISCH 
 
 thereby conceive an actual possibility, which is a gross ab- 
 surdity. 
 
 In this merely logical sense we will not want to have the con- 
 cept of possibility taken, but we seek to express thereby, that 
 an activity is existent in the germ (potentia), and only awaits 
 the opportunity to develop into actuality (actu). We cannot, 
 indeed, strictly mean thereby, that the activity is retained 
 wholly as it afterwards manifests itself, only in a concentrated 
 undeveloped condition in the mind, so that, therefore, e.g., the 
 sensuous ideas before they appear in consciousness through 
 stimulation of the senses, dwell in the mind in the same way as 
 they abide in the recesses of the memory, after they have be- 
 come forgotten. This would make every excitation of ideas 
 from without a mere appearance, and would therefore be a 
 view compatible only with the most thoroughgoing idealism. 
 This is rather what we mean, that, just as the seed-corn, in order 
 to germinate and develop, requires earth, air, moisture, and 
 warmth, but nevertheless these potencies can still bring into 
 development only a seed-corn, but by no means a stone, or even 
 a blossom; so likewise a diversified capacity for forming ideas, 
 is to be understood as belonging to the mind, by virtue of which, 
 if certain external conditions are associated therewith, an 
 actual formation of ideas take place in it. 
 
 If we would discuss this concept metaphysically we should 
 put the question, whether the multiplicity of capacities har- 
 monises better with the demanded unity of the soul, than a 
 multiplicity of actual powers; or whether the soul, if it origin- 
 ally carries in itself as the mode of its existence such a multi- 
 plicity of capacities, would be strictly regarded anything more 
 than a system of the same, therefore, a compound, and what 
 then must be deemed the significance of these capacities apart 
 from this compound? But this may be left out of the present 
 discussion. 
 
 Possibly one might think of seeking aid through the analogy 
 of physics, by saying that the activity is still united to the 
 capacity, latent, and becomes free through development under 
 the cooperation of external conditions. To this suggestion we
 
 EMPIRICAL PSYCHOLOGY 437 
 
 should oppose the observation, that latent heat or electricity 
 presupposes the free ; that this latter is the first and original, the 
 former only the secondary and derived condition. Latent activ- 
 ities of the mind may therefore indeed be termed ideas stored 
 in memory beyond consciousness; but the ideas originating 
 according to common conviction through sensory impressions 
 if, as becoming free, they are to be viewed as previously bound, 
 would have to be taken as platonic remembrances out of a pre- 
 vious existence, and their sensuous origin would have to be a 
 vain delusion. To prove this latter has up to now been impos- 
 sible for any scepticism, or any idealism. 
 
 141. IDEAS AS STATES AND NOT POWERS 
 OF THE MIND 
 
 According to the foregoing every return to faculties, or power 
 of forming ideas, in whatever way we may conceive these, ap- 
 pears to lead to no acceptable result. We must, therefore, at- 
 tempt to obtain another point of view of ideas, which without 
 being content to regard them as mere inner phenomena, ex- 
 plains both their existence, and promises to make conceivable, 
 as coming from them, feelings and desires. In this attempt the 
 comparison with physical science affords us the safest guidance. 
 If the physicist says that this body possesses the capacity to be- 
 come more heated, luminous, electrical, magnetic, to resound, to 
 enter into many chemical combinations, etc., he does not mean 
 by that, that the body possesses certain faculties or dormant 
 powers, which under certain conditions can awaken and produce 
 those phenomena, but he signifies thereby only certain disposi- 
 tions or qualities of the body, whether these may have their 
 location in the bulk of its matter, in its mechanical composi- 
 tion, or in the relation of the quality of its matter to that of some 
 other body. If we here speak of a force as the cause of such 
 a physical condition of a body, it is not transferred to this, but 
 is established outside of it, and the body appears only as a thing 
 which is placed in a certain condition, to which we do not on that 
 account ascribe peculiar powers; or would we attribute to a
 
 438 MORITZ WILHELM DROBISCH 
 
 heavy body a power to fall, to the resonant a power to sound? 
 How far even the older physics was from any such theory as 
 this, its hypothesis of a force of inertia shows. It did not 
 attribute to a mobile body a power of movement, but a power 
 to resist movement. The new physics, on the other hand, dis- 
 cards both, and views rest and motion as states which are alike 
 accidental to the bodies, but if they are placed in them, they 
 continue unchanged until a removal or modification of the same 
 ensues. The thought of the capacity of bodies for these states 
 drops entirely as idle and unfruitful. 
 
 To heed this example of physics might now be by far the 
 most profitable method for psychology. It has been already 
 remarked above, that in our immediate consciousness the form- 
 ing of ideas appears neither as an actuality, nor a capacity of the 
 mind, but only as a happening in it. Accordingly, in harmony 
 with experience, we will designate the ideas as states of the 
 mind, and can affirm at least of the sensuous ideas, which form 
 the basis of all others, that the mind is placed in these states by 
 means of external causes through the agency of the organs of 
 sense, which, like the produced motion of a body, continues un- 
 changed so long as they are not removed or modified by addi- 
 tional inner or outer causes. We consequently lay claim to the 
 principle of permanence (the law of inertia) for these states, 
 and regard the mind as existence in itself, barren of ideas, and 
 accordingly also of feelings and desires, which, on account of its 
 simplicity, can attain to those states only through the manifold 
 relations of its quality to the qualities of the things with which 
 it stands in relation, comparable to chemical affinity. 
 
 The nature and mode in which exterrial things affect the 
 mind, the conditions of the production of any idea, remain 
 partly physiological and partly metaphysical problems. But 
 since it is assumed, that the manifoldness of the relations of the 
 individual mind to the external causes of its simple ideas cre- 
 ates likewise a manifold constitution in the latter, the question 
 how the unity of the mind is consistent with the multiplicity of 
 its inner happenings has at least in general no more difficulties. 
 One and the same number can enter into infinitely numerous
 
 EMPIRICAL PSYCHOLOGY 439 
 
 relations, and the exponent of the relations is in every case a 
 different one. With such exponents the ideas may be compared ; 
 and with the common fundamental unit (the first member) of 
 them, the mind itself may be compared. But if one desires 
 more than comparisons, one has then to do with metaphysics, 
 which has to discuss this question in the systematic relation of 
 concepts. For the immediate purpose it suffices to observe that 
 the formation of ideas must be conceived not from the point of 
 view of a manifestation of power of the mind, but as a state of 
 the same, or as a happening befalling it. The ideas must not be 
 compared with powers, but with movements of the mind; and 
 if a sensuous image is desired, they can best be compared with 
 the oscillations of a body, otherwise externally at rest. 
 
 142. THE FREEDOM AND INHIBITION OF IDEAS 
 
 The facts of the changing attention and of the disappearance 
 of ideas from consciousness, as well as their reappearance in 
 it, reveal clearly, that ideas although themselves only states of 
 the mind, nevertheless are capable of having in their turn dif- 
 ferent states of their own. These are the states of freedom and 
 of inhibition of ideas. An idea will then be free, if simultaneously 
 there be represented no others of opposite quality, but only of a 
 like or dissimilar constitution. But if opposed ideas occur sim- 
 ultaneously, a diminution of that freedom takes place, which 
 can be termed inhibition. For as experience adequately shows, 
 ideas do not mutually suppress one another, not even when 
 some of them become forgotten for they can be again 
 aroused under certain conditions but they are merely 
 brought into a state in which they cease wholly or in a certain 
 degree to be ideas; but for all that are neither destroyed, nor 
 suffer a diminution of their being, which rather assumes only 
 another form. This is the form of striving. 
 
 In the same degree namely, in which vividness or the con- 
 scious clearness of an idea diminishes, in that degree a resist- 
 ance to this violent state and a striving to free itself there- 
 from arises in it. Under such circumstances the idea certainly
 
 440 MORITZ WILHELM DROBISCH 
 
 becomes a force, but one which is directed against a definite 
 hindrance obstructing its freedom. It ceases at once to be a 
 force so soon as that hindrance disappears, and it has attained 
 again its natural uninhibited state. In this striving is found the 
 principle for the explanation of desire ; it would, however, be 
 rash if one were to affirm this striving to be in general the desire 
 itself. For manifestly no idea could disappear from conscious- 
 ness, unless its return were desired; and all ideas, which we any 
 time have had and have long since forgotten, would have to 
 be desired, and consequently press for return into conscious- 
 ness. Of this, however, we do not observe the least, and we are 
 not even aware of any such pressure on the part of the ideas, 
 from which our attention is momentarily diverted. A conscious 
 and an unconscious striving must therefore be distinguished, 
 and the conditions of this distinction must be investigated. 
 
 143. THE. INHIBITION OF OPPOSING IDEAS 
 
 In fact our inhibited striving is to be conceived as at one 
 time united with the feeling of pressure, and as at another time 
 without any such feeling. This indicates an essential difference 
 in the inhibition, according as this occurs before or after the 
 complete balancing of the opposing striving of ideas. The 
 former is combined with a feeling of obstruction, the latter is 
 free therefrom, and can be termed an equilibrium of ideas, 
 which takes place within or without consciousness, according as 
 the balanced ideas are in part only, or wholly inhibited. Ideas 
 which are not yet in equilibrium will possess a striving after it; 
 for only the balanced condition can have a point of rest, and the 
 inhibition connected with it will be that which under the given 
 circumstances imposes upon the ideas the least proportionate 
 pressure. More precise determinations of this state, the condi- 
 tions of equilibrium of ideas, cannot be developed without the 
 aid of mathematics. Ideas in equilibrium are united in general 
 neither with feelings nor with desires; but both accompany the 
 still unbalanced ideas. Feelings and desires as distinct from 
 ideas are inconceivable. They lack a definite representable
 
 EMPIRICAL PSYCHOLOGY 441 
 
 what, a quale; nevertheless they are actually in consciousness. 
 They must, therefore, be found in it as the manifold changeable 
 how of presentation. Wherein now does this consist, and how 
 do they differ from one another? By what means do I know of 
 my desires? Do I perceive an act of desire immediately? Not at 
 all, I certainly feel only the state of desire, but still distinguish 
 therefrom the feeling which accompanies it. The desire destroys 
 the calm, the equilibrium of the mind, or to speak more cor- 
 rectly, the equilibrium of its ideas. If I have a feeling of this 
 equilibrium, a change in it will be a feeling of disturbance. The 
 feeling of psychical equilibrium is precisely similar to that of 
 bodily health. Of both there exists no positive feeling. The 
 body as well as the mind is in a state of equilibrium when one 
 has no feeling of its activities, just as a machine in which there 
 is the least possible friction makes but little noise. Desires and 
 feelings are, therefore, the indices of the deviation from the 
 state of equilibrium of ideas. 
 
 It is to be remembered if we wish to comprehend their differ- 
 ence, that desires are the activity, feelings the passivity of the 
 mind. Now desire is the striving of that idea, whose content is 
 desired, against obstructions, which have their ground it is true 
 outside of the mind, but nevertheless must be felt by it, since 
 otherwise the striving idea, which always abides in the mind, 
 would find no obstruction. Obstructions are, therefore, at least 
 in the broadest sense of the term, themselves ideas. But whilst 
 the hindrances obstruct, they react against the striving idea, and 
 thereby become unpleasant. This latter idea presses and is 
 pressed ; in it is the seat of desire ; in its obstructions is the seat 
 of the unpleasant feeling of resistance united therewith. The 
 overcoming striving of an idea against such obstructions is 
 therefore the desire of its content; and the succumbing resist- 
 ance of what is opposed is therefore the painful feeling, which 
 is constantly united with the postponement of the attainment 
 of what is desired. The former is the striving, the latter is the 
 suffering of the one desiring. The desire is, therefore, not felt 
 only in the idea of the desired thing, also not alone in that 
 which resists it, but in both at the same time, and in their rela-
 
 442 MORITZ WILHELM DROBISCH 
 
 tion, which is none other than the disturbance of the preceding 
 equilibrium. But the striving idea, however, does not itself 
 alone possess the power for this disturbance, but gains it only 
 through union with an internal or external perception related to 
 it, which reproduces and lifts above the point of equilibrium, 
 and which therefore appears as the external cause of the origin, 
 or the reawakening of desire. The desire appears herewith as a 
 progressing or retrogressing movement of ideas; if we regard 
 the maximum of their clearness as the goal or culminating 
 point. But the mind itself is thereby immediately neither 
 active, nor passive. It is both, only mediately, in so far, that is 
 to say as its ideas are found in these states. 
 
 144. THE ORIGIN OF FEELINGS AND DESIRES 
 
 This is the first, and, to be sure, only a very meagre outline 
 of the origin of feelings and desires, of which a further and more 
 exhaustive explanation would demand a more exact and more 
 varied development of the explanatory principle postulated as 
 its basis, than is here possible and consistent with the desired 
 ami. Nevertheless, it is at least possible to add the following 
 corollaries. 
 
 (1) Just as the idea striving against abstractions causes 
 desire, the idea retreating reluctantly from consciousness 
 causes repugnance. For manifestly the content represented in 
 it is the object of repugnance, but the energy of the repugnance 
 is contained in the ideas opposed to this idea, which repel and 
 gradually suppress it; the stronger the resistance of the reced- 
 ing idea, so much the stronger is the emotion of abhorrence. 
 
 (2) Feelings of oppression can also arise without desire and 
 abhorrence, that is to say, without a progressive or retrogres- 
 sive movement of ideas. For granted an idea is in itself too 
 weak to continue in consciousness when opposed by many 
 stronger ones, and thus to be in equilibrium with them, it can 
 nevertheless happen by the following means, that it is asso- 
 ciated with an idea of a dissimilar content, which affords the 
 support demanded for equilibrium with the others. The
 
 EMPIRICAL PSYCHOLOGY 443 
 
 memory-image of the room which I occupied many years ago 
 as a schoolboy is itself not capable of continuing beside the 
 intuitions of the present; but if by a related perception the 
 damp, musty smell is reproduced, which at that time made its 
 occupancy not the most agreeable, then the image emerges 
 with full vividness and continues in my consciousness. But 
 nevertheless, any such recollection always demands a certain 
 effort, and this consists in the fact that the retained idea is in a 
 pressed position between the opposed ideas seeking to sup- 
 plant it, and those dissimilar which afford to it the necessary 
 support. Hence arises a feeling of oppression. 
 
 (3) An idea, finally, can also arise notwithstanding opposing 
 hindrances, that is to say, when this rising occurs under the 
 protection of a stronger idea entirely homogeneous with it, 
 which removes the obstacles in its way, and thereby makes for 
 it a free path. Then the obstacles disappear as if dispelled by 
 magic, like the impotent spectres of the night before the light 
 of day. Under such circumstances the rising idea possesses more 
 elasticity than it can expend, and the character of its move- 
 ment creates a feeling of pleasure. 
 
 With these corollaries we must here be content, for the condi- 
 tions under which the feelings of the good and the beautiful 
 arise, lie too deep to permit of being here developed with any 
 clearness. 
 
 145. THE EQUILIBRIUM AND MOVEMENT OF 
 
 IDEAS 
 
 The concepts of freedom and inhibition, of equilibrium and 
 movements, of striving and resistance of ideas, developed with 
 the sharpest lines of differentiation, must henceforth, solely and 
 alone, take the place of the theory of the abstract faculties of 
 ideas, feeling, and desire, as explanatory principles. But they 
 serve, moreover, to supplant the more special faculties sub- 
 ordinated to these in a manner more conformable to experi- 
 ence. Our entire analysis of psychical phenomena must have 
 demonstrated, that association and reproduction are the keys
 
 444 MORITZ WILHELM DROBISCH 
 
 which open the portals of the inner life of the soul. But the 
 principles themselves henceforth can be proved to be derived 
 from others lying deeper. For association is the result of the 
 unity of the soul, by means of which all the states of the latter, 
 so far as their contrasts admit it, unite and enter combinations 
 under all circumstances. But reproduction rests in part imme- 
 diately upon associations, and in part upon the concepts of free- 
 dom and inhibition of ideas. 
 
 In general the apparent manifestation of the faculties of the 
 mind rests upon combinations, aggregations of ideas in the 
 large, which we can style with Herbart masses of ideas (Vors- 
 tellungsmassen) , which developed with more or less regularity 
 are interwoven out of series, and series of series; and move- 
 ments and transformations of these masses of ideas appear in 
 place of the activity of the faculties. The individual faculties 
 are distinguished in part formally by the different kind of the 
 formation of the masses in which they have their location ; and 
 in part materially by the kind of ideas which make up the mate- 
 rial of the mass. By means of the latter we can understand the 
 so frequently occurring partiality of memory, of imagination, 
 and of the understanding. 
 
 Memory, therefore, we may ascribe to our mind in so far as it 
 possesses ideas, which still bear the characteristics of their first 
 origin, and which return to consciousness, out of which they 
 have been crowded by others, according to the same temporal 
 order as that in which they originated, in that train of recol- 
 lected thought which is conformable to the laws of memory. 
 
 Imagination we can ascribe to our mind in so far as it pos- 
 sesses ideas, in which the characteristics of their first sensuous 
 origin are obliterated, which therefore no longer occupy a 
 definite place among other after images of former perceptions, 
 and are no longer reproduced in the temporal sequence of the 
 same. But the most manifold combinations are entered upon, 
 according to all the laws of association, which enable it to 
 perform even as manifold reproductions, and to give them that 
 easy mobility, by which the making of more and more numer- 
 ous combinations of surpassing novelty is rendered possible.
 
 EMPIRICAL PSYCHOLOGY 445 
 
 Understanding belongs to our mind in so far as there exists 
 in it masses of ideas whose combinations, independent of all 
 accidental circumstances of their encounter, are completely 
 adapted to the nature of their content, and therefore corre- 
 spond to the relations of things ; it may be, that, as in theoretical 
 understanding, this content is sharply separated in conceptual 
 definitions, or, as in the practical understanding, is rightly recog- 
 nised only in relation to the content of another idea. 
 
 Our mind possesses will, in so far as it has masses of ideas, 
 whose content represent what is willed, and whose striving 
 exercises a decisive control over other ideas and combinations 
 of ideas. 
 
 The mind is rational, if the moral insight has become the 
 kernel and centre of the mass-of-ideas ruling all others. But 
 man as a natural creature is called rational in so far as adapta- 
 tions have been made in his physical organisation, which makes 
 possible the development of moral insight, and the attainment 
 of it to power, but do not prevent it as in the case of the lower 
 animals. 
 
 Finally with momentary perceptions the mind possesses 
 sensibility. 
 
 146. THE STAGES IN THE FORMATION OF THE 
 
 SPIRIT 
 
 With this explanation and limitation of the apparent faculties 
 of the mind the view can now be united, which discerns the 
 different stages in the formation of the spirit. Indeed it is ob- 
 vious, that thereby the transformations must at the same time 
 be considered, which affect the body in its different periods of 
 life, and which without doubt favor and support the psychical 
 processes. But after the subtraction of these bodily condi- 
 tions there remain nevertheless always a series of purely 
 psychical transformations residual, resting chiefly upon the 
 changes which take place in the combinations of ideas. 
 
 Ideas are barren of connection and therefore purely sensuous 
 in their first origin in the newborn child, but after a short time
 
 446 MORITZ WILHELM DROBISCH 
 
 those associations have already been formed which are neces- 
 sary to memory, and a little later that desire appears, which 
 not always the need of food, but often only the sight of the 
 nurse calls forth. In the boy, it is true, highly manifold com- 
 binations of ideas have been formed, and we must concede to 
 him memory and imagination, understanding and will, in very 
 many spheres of his capacity for forming ideas. But neverthe- 
 less, sensibility, memory, and imagination still dominate in him, 
 to which his fondness for sweetmeats, his love of sightseeing and 
 curiosity, his ability for learning by heart, his joy in narratives 
 of adventure, his desire for sport, sufficiently testify. The 
 youth begins to feel : the scattered ideas concentrate in him to 
 form a more abiding and more powerful empirical self, by which 
 he not only acquires power over his actions and thereby be- 
 comes responsible, but also learns to guide his imagination in 
 poetic composition, and to formulate his thought in reflection. 
 With higher self-consciousness the inner world opens before 
 him, and with it the finer feeling for the beautiful in nature, art, 
 poetry, and the other sex. Still experience is lacking, which 
 gives maturity to the understanding. This manhood gives with 
 increasing needs and cares, for the supplying of which under- 
 standing must serve; but the execution of its decisions de- 
 mands energy of the will, and the duties to society and to the 
 family, a moral content of the will. Self-control must, therefore, 
 now be present in constant increase, and a constant, true, and 
 reasonable activity towards the outer world must take the 
 place of youthful vacillation. With self-control reason is finally 
 acquired, the strength of which must increase in the same meas- 
 ure as that in which sensuous impressionability, the power of 
 desires and passions, decrease. 
 
 Thus the combinations among ideas become greater in num- 
 ber, and more perfected in the course of life, and as a result of it 
 restrain and control its movements. The stress of emotions and 
 passions give place to more mature considerations ; absentmind- 
 edness and the flightiness of imagination yield to the sharp 
 attention and many sided circumspectness of reflection; know- 
 ledge tempers the disquietude of doubt; and when this know-
 
 EMPIRICAL PSYCHOLOGY 447 
 
 ledge can go no further, faith succeeds to its function. The 
 entire development of the mind progresses always towards a 
 more and more harmonious form, and its activity towards a 
 more and more peaceful movement. But there are not newly 
 awakening faculties of the mind which produce this change of 
 phenomena; but there are always only the ideas, their com- 
 binations and movements, ideation and its states, by means 
 of which they become intelligible.
 
 FRANCOIS PIERRE GONTHIER 
 MAINE DE BIRAN 
 
 (1766-1824) 
 
 ESSAY UPON THE FOUNDATIONS OF 
 PSYCHOLOGY 
 
 Translated from the French* by 
 BENJAMIN RAND 
 
 CHAPTER I. FACTS OF THE INNER SENSE 
 
 I SHALL characterise from the present this inner sense (sens 
 intime) in a more explicit manner under the name of sense of 
 effort, .of which the cause or productive force becomes self, by 
 the single fact of the distinction which is established between 
 the subject of that free effort, and the object which resists im- 
 mediately through its own inertia. I say immediately, in order 
 to announce here in advance another very essential distinction, 
 that I believe myself authorized to set up between the resist- 
 ance or relative inertia of one's own body, which yields to or 
 obeys voluntary effort, and the absolute resistance of the for- 
 eign body, which may be invincible. 
 
 . The sense of effort has not been designated until now by its 
 specific name, precisely because it is the innermost, or the 
 nearest to ourselves, or rather because it is ourselves. If one 
 should demand at this stage to be made acquainted with it by 
 a more detailed exposition, I should reply, that each of our 
 senses defines itself by its exercise. If there were, for example, 
 one born paralytic who had never acted voluntarily to move 
 
 * From Maine deBiran's Essai sur les fondements de la psychologic (1812), in 
 his (Enures intdites, publics par Ernest Naville, Paris, 1859, torn. I.
 
 MAINE DE BIRAN 449 
 
 his b'mbs or to set in motion foreign bodies, supposing that 
 such a person, which appears impossible to me, could have 
 had the least degree of intelligence, there would be no more 
 possibility to make him understand by language what effort is, 
 than there is to explain to one born blind what color and the 
 sense of sight are. Nevertheless, as one explains not the sense 
 or the phenomenon of vision, but rather the conditions, in- 
 struments, and physical or organic means, which serve to effect 
 it, it will perhaps not be useless to analyse also physically 
 the instruments and means of exercise of the internal sense of 
 effort, in order to learn the better to circumscribe its domain 
 by distinguishing it from that of an external sense with which 
 it might be confused. I shall therefore enter upon some con- 
 siderations which appear to me important. 
 
 This study, foreign as it is to the proper analysis of the phe- 
 nomena of the inner sense, which excludes everything that be- 
 longs to the province of external observation, will be included 
 more expressly in the object of another portion of this work, 
 where we shall be occupied more particularly with the relation 
 of the phenomena of physical or organic nature than with those 
 of psychology; but I cannot proceed without giving the follow- 
 ing physiological hints as indispensable to my actual purpose. 
 
 1 . The organs of sensation with which the physiologists have 
 heretofore been exclusively occupied, appear confined to the 
 cerebral nervous system, distinguished by a well known ob- 
 server l under the title of the Nervous system of animal life. The 
 sense of effort, here in question, is limited by that part of the 
 muscular system, which the action of the will expressly sets in 
 play, and which physiology distinguishes also under the title of 
 a System of the voluntary muscles of the animal life. 
 
 2. In the natural and original state of the sentient being 
 there is no affection felt in any part whatsoever of its organism, 
 nor any object perceived externally, except in so far as the nerv- 
 ous extremities are at first excited by some cause foreign to 
 the self, and as this first impression is uninterruptedly trans- 
 mitted by the sensory nerves which receive it as far as the 
 
 1 Cf. Bichat's works: De la vie el la mart and Anatomic Physiologique.
 
 450 THE FOUNDATIONS OF PSYCHOLOGY 
 
 centre of the brain, where perception is supposed to occur, 
 although we are profoundly ignorant of what takes place in the 
 nerves and the brain whenever an impression is felt or per- 
 ceived. Nevertheless, daily experience proves that such percep- 
 tion is always preceded or accompanied by the organic condi- 
 tions which we have just mentioned. But in the exercise of the 
 sense of effort something more takes place. 
 
 Let us first suppose that the muscular organ be excited by an 
 external cause, or by a stimulus adapted to set in play that vital 
 property that the physiologists name irritability or sensory 
 organic contractility; or again, let us suppose that a movable 
 part may be aroused or strongly agitated by an external force, 
 there will indeed clearly result from it a particular impression, 
 which one may call muscular sensation or sensation of move- 
 ment, but which could not be confused with that mode of our 
 activity which we designate by the term of willed effort. In 
 fact, this muscular sensation is subject to the same laws or 
 organic conditions which determine the general sensory func- 
 tions; it is always an impression received and transmitted to 
 the brain, where it is felt as a passive mode foreign to the will or 
 to the self. But in effort such as we perceive and reproduce at 
 each instant, there is no excitation, no foreign stimulus, and 
 nevertheless the muscular organ is set in play, the contraction 
 effected, the movement produced, without any cause other 
 than this inner force which is felt or immediately perceived in 
 its exercise, and also without any sign being capable of repre- 
 senting it to the imagination or to some sense other than its own. 
 
 Let us however represent this force in exercise by an image, 
 and, by placing ourselves for a moment at the physiological 
 point of view, let us suppose that it be localised in the centre of 
 the brain. When the effort is made, this central spring to the 
 release of which there is referred by a sort of imaginary fiction 
 the feeling of our activity, will be said to enter into action of it- 
 self. 1 I adopt this last expression, as a material sign of voluntary 
 effort, or of an action which is neither actually compelled nor 
 
 1 An expression of M. Cabanis in his great work upon the Rapports du 
 physique et du moral de I'homme.
 
 MAINE DE BIRAN 451 
 
 provoked by any sensory impression coming from without, nor 
 even produced in any part of the nervous system outside the 
 centre. The first motor determination being thus begotten in 
 the centre, is immediately transmitted by the nerves to the 
 muscular organ. This is contracted, or extended; its specific 
 irritability is set in action, as it could be by a foreign stimulus. 
 But, whereas, in this last case, the simple passive muscular 
 sensation commences at the external organ in order to termi- 
 nate at the centre which receives it; here the active motor 
 stimulus commences in the centre where the cause resides, 
 which, after having performed the contraction or movement, 
 perceives as effect by means of the nervous transmission the 
 muscular impression which it originates in the beginning. I 
 here discover the symbol of complete action, the physiological 
 signs of which I must endeavor to analyse more expressly; be- 
 cause, it is upon these signs alone that the analysis can here 
 be based, since every action of the will is truly indivisible and 
 instantaneous as known through the inner sense. 
 
 In considering, therefore, this action from the point of view 
 of physiology, I distinguish two elements, or two moments, 
 in which it is accomplished. To the first corresponds the simple 
 motor determination or the release of the central spring 
 affecting the nerves. However, that part of the action, thus 
 limited -to the nervous system, does not appear to be accom- 
 panied by a particular internal perception; but supposing there 
 were such perception, and that it were not such as to be neces- 
 sarily confused with that of resistance or inertia of the con- 
 tracted muscle, which accompanies or immediately follows it, 
 one still could not regard it as the symbolical sign of individual- 
 ity or of the self, which can begin to know itself, or to exist for 
 itself, only so far as it can distinguish itself as subject of effort 
 from an object which resists. Thus the kind of obscure per- 
 ception which would correspond to this incomplete action 
 which is performed from a single centre upon a homogeneous 
 nervous system, would be still only a vague and confused feel- 
 ing of existence, to which perhaps some species of animals are 
 limited. To the second moment corresponds that which takes
 
 452 THE .FOUNDATIONS OF PSYCHOLOGY 
 
 place in the motor system, from the instant when the muscle 
 contracts, until the effect of the contraction is transmitted or 
 carried to the centre, where the muscular sensation then takes 
 on this characteristic of reduplication which constitutes the 
 inner consciousness of effort, inseparable from a resistance, or 
 the inner consciousness of the self which knows itself by dis- 
 tinguishing itself from the resisting object. 
 
 Let us now pass from the symbol or the sign to the thing sig- 
 nified, and compare the internal facts with the hypotheses or the 
 physiological facts. 
 
 We know, from a very constant experience, that the sentient 
 being can never give to itself by any exercise of its activity, 
 those agreeable or disagreeable impressions which affects it in 
 spite of itself; that it is not the artisan nor the creator of those 
 sensations or of those images which come into existence, suc- 
 ceed one another or disappear, without any concurrence of its 
 will, or even against its desire. We know, moreover, from the 
 observation of sentient nature, and from the various experi- 
 ments of physiologists, that there exist sure and constant 
 means to set in play the animal sensitivity by appropriate 
 excitations, and to draw from the sentient being all the signs of 
 the affections, of pain, or of physical pleasure, that one makes it 
 undergo. The internal sense of effort on the other hand can be 
 set in play only by this force, which is interior and sui generis, 
 that we call will, and with which what we call our self is com- 
 pletely identified. 
 
 The power of effort, or the ability to commence and to con- 
 tinue any series of movements or of actions, is a fact of inner 
 sense as evident as that of our existence itself. There is no for- 
 eign force to which that power is necessarily subordinated. 
 Observe thus, how powerless all the external or artificial means 
 may be which would tend to imitate the results of that acting 
 force, or to reproduce and to provoke the signs of its manifes- 
 tation. If you apply a stimulus, either directly upon a muscle, 
 or upon the trunk, or the nervous centre which send ramifica- 
 tions to it, you of a certainty bring about contractions, sensed 
 in the li ving, and purely organic in the dead. In regard to the
 
 MAINE DE BIRAN 453 
 
 will of man, or the power of effort, it dwells in independence in 
 the innermost being, beyond all reach of any excitation from 
 without. Neither the inducements of pleasure, nor the goads of 
 pain, are capable of irresistibly compelling it. When it exer- 
 cises itself, all physiological laws are disturbed; all the ex- 
 ternal signs of sensitivity or of contractility are uncertain, and 
 can be quiescent or deceptive. How powerless, for example, 
 the most excruciating pain over the will of a Mucius 
 Scevola? Before it yields, the arm which it holds motionless 
 upon the burning coals will be reduced to ashes. Is not then the 
 force which thus dominates sensibility and rules it by its own 
 laws, which compels the body to stop or to rush forward, even 
 when its instinct urges it to flight, a force that is specific and 
 sui juris. 
 
 But still we cannot speak of that moral force guided by 
 motives which can render effort sublime. Before motives to 
 act exist, there is surely a power of movement or of action ; be- 
 fore this movement has become means, it has first been itself 
 the aim or proper end of the willing. Finally it is necessary that 
 the self shall have begun to exist for itself, or to circumscribe 
 itself in its own domain, before extending over nature its 
 constitutive force. Thereby are justified those considerations 
 which might appear to us somewhat too minute, and to others 
 too closely allied to this materialism which they are calculated 
 to attack in its first foundation. 
 
 For us, therefore, who are here occupied only with a primi- 
 tive fact of the inner sense, the will is as yet only the power of 
 effort. We have just characterised this force through the signs, 
 or the first conditions, or the instruments of its exercise. We 
 now need to seek by analysis, what may be the origin of this 
 exercise, and that of the individual personality which cannot be 
 separated from it. But before entering upon this analysis, let 
 us summarise the consequences of what precedes. 
 
 i . The primitive fact of the inner sense is none other than that 
 of a voluntary effort, inseparable from some organic resistance, 
 or from some muscular sensation of which the self is cause. This 
 fact is thus a relation of which the two terms are distinct with-
 
 454 THE FOUNDATIONS OF PSYCHOLOGY 
 
 out being separated. In order that they should be separated, 
 it would be necessary, under the physiological hypothesis taken 
 as a symbol, that the immediate action exerted from the centre 
 upon the motor nerves be accompanied by a particular internal 
 perception, distinct and separate from the muscular sensation ; 
 but therefore, the same internal perception would consist in an- 
 other relation still more inner, between the hyperorganic force 
 exerted from the centre and the nerves upon which it immedi- 
 ately acts. It would be, therefore, the nervous inertia which 
 would replace in that case the muscular inertia, and the charac- 
 ter of the primitive fact would not be changed. 
 
 2. The essential character of the primitive fact consists in 
 that, that neither one nor the other of the terms of the funda- 
 mental relation is constituted in necessary dependence upon the 
 impressions from without. Hence the knowledge of the self can 
 be separated in its principle from that of the external universe. 
 
 3. The effort-cause, or the self has the internal consciousness 
 of its existence as soon as it can distinguish this cause, which is 
 itself, from the effect or from the contraction referred to the 
 organic object, which is no longer itself, and which it places 
 outside. 1 
 
 4. The primitive fact which necessarily serves as the point 
 of departure to science, therefore resolves itself into a primary 
 effort, where analysis is still able to distinguish two elements: a 
 hyperorganic force naturally in relation with a living resistance. 
 
 5. The idea or reflexive abstract notion of force is later 
 deduced from the fact, or from the primitive feeling of effort. 
 In following an inverse course and starting from the idea of 
 absolute force, all the metaphysicians, up to and inclusive of 
 Locke, have displaced the origin of science. They have desired 
 to deduce the actual and the real from the possible: that was 
 to begin in darkness. 
 
 We do not fear to lose ourselves in darkness by seeking at 
 present how effort can begin to be willed, what the origin is of 
 this primary action, of this free will, which is the primary condi- 
 
 1 We shall see that this outside is not external extensity, nor even the form of 
 space, such as the Kantians conceive it, as inherent to sensibility.
 
 MAINE DE BIRAN 455 
 
 tlon of the consciousness of one's self, and, consequently, of all 
 other consciousness. We have a thread which guides us in these 
 researches, and which, if it does not lead to the absolute truth 
 which we seek, enables us at least not to lose ourselves in ideal 
 regions, whence there would be no outlet or means to retrace 
 our steps. 
 
 CHAPTER II. THE ORIGIN OF EFFORT, AND OF 
 PERSONALITY 
 
 IF it were true, as philosophers who have attempted to 
 derive everything from desire think, that will were nothing 
 other than desire, which itself is confused with a first need of 
 the organised living being ; if it were true, or conformed to the 
 facts of the inner sense, that instinctive determinations, re- 
 garded as completed sensations, embraced judgment, desire, 
 or will ; if finally it were true, that the very first movement made 
 by each of us had been accompanied by will, it would be very 
 useless to seek, I do not say, the origin of that absolute force 
 identical with the soul, or of that which stands for it in all sys- 
 tems, but the origin of the feeling of its exercise, or of the effort 
 with which the ego identifies itself. This origin indeed would be 
 confused with the first rudiments of life, and would be traced 
 back to the organic germ which possibly exists before fecunda- 
 tion. If this system were that of nature, it would turn out I have 
 pursued up to the present only a chimera, and all the precise 
 distinctions I have sought to establish would disappear like 
 vain shadows. The obligation is thus imposed upon me to 
 make it evident that my present researches have a real object, 
 or that there may be an origin of voluntary effort or of the 
 self, posterior in order of time to the birth of the sentient being, 
 to the first instinctive determinations, to the needs, and even 
 to the desire, which differ from the will, properly so called, as 
 passion differs from action. 
 
 I am going at the outset to place myself anew at the physi- 
 ological point of view, and upon the very ground of the 
 philosophers who have assimilated or confounded in the origin,
 
 456 THE FOUNDATIONS OF PSYCHOLOGY 
 
 everything that I believe should be distinguished or even 
 separated, in order to have a science of principles. If the dis- 
 tinctions that I establish turn out to be confirmed by physio- 
 logy itself they are doubtless likely to receive in consequence 
 more weight and value in the eyes of those to whom I take the 
 liberty of opposing them. 
 
 According to the principles of a physiologist, 1 who was gifted 
 with the genius of experiment rather than with the talent for 
 classification, one is justified in the recognition of three modes, 
 or three kinds of muscular contractility, which are distin- 
 guished among themselves in the same manner as the causes 
 which produce or determine the contractions. The first kind is 
 a simple organic property inherent to the muscular fibre, and 
 which has been known since Haller by the term irritability. We 
 have no need to know up to what point the nervous influence 
 contributes to set it in action, because this property, simply 
 vital, happens to be outside of the object of our researches. 
 V/hat is of importance to us, is to recognise the truly distin- 
 guishing characteristics in the sentient contractility, which may 
 also be called animal, and a contractility properly voluntary. 
 Let us seek, therefore, to specify clearly the physiological char- 
 acteristics of these two kinds. Both of them expressly relate to 
 cerebral influence, but under very different conditions, and it 
 is not permissible to confuse them even physiologically. 
 
 Affective impressions excited in the nervous system by for- 
 eign or inner causes, being transmitted to the brain or to some 
 other of the partial centres, determine those powerful reactions 
 which tend to set in play the locomotor organs: hence the ani- 
 mal contractions and all the instinctive movements. I have 
 just spoken of partial centres as of points of reaction, because 
 it is not proved that it is the direct influence of a single centre 
 which determines always the instinctive locomotion of animals 
 as of the foetus, and several analogies tend to prove the opposite. 
 Supposing, what appears to be contradicted by many physiolog- 
 ical observations, that a single centre determines solely by its 
 reaction the kind of movement which is in question here, at 
 
 1 Cf. Bichat's Rcckerchcs pkysiologiqucs sur la vie ct la mart.
 
 MAINE DE BIRAN 457 
 
 least it is true that this centre plays in that case a passive or 
 merely sympathetic role influenced, as it is, by the impres- 
 sions of the internal or external nervous organs which are the 
 true determining causes of these animal contractions. 
 
 But in the contraction that is strictly voluntary, it is clearly 
 in a single centre that the action commences which, without 
 being provoked or compelled by any foreign impression, is 
 transmitted directly to the organs of movement by the inter- 
 mediary of the nerves. We find here the only true sign of vol- 
 untary effort, such as we have characterised it. 
 
 As the voluntary contraction thus differs from the animal 
 contraction, so likewise the will, the individual and free power 
 of effort and movement, differ from appetite, need, and all feel- 
 ings of discomfort, of disquietude, etc. which have been arbi- 
 trarily united under the general term of will. Here both the psy- 
 chological and physiological points of view perfectly correspond. 
 The sympathetic reaction of the centre, which occasions the 
 animal contractions or the instinctive movements, is the sign of 
 aflective desire very improperly called will. The action, com- 
 mencing in a single centre, which occasions the voluntary 
 movement that is in the power of the individual to make or not 
 to make, is the proper sign of an impelling will. The general 
 faculty in question from the first physiological point of view, is 
 not only subordinated to, but identical with the sensibility con- 
 sidered as the principle or the cause which determines animal 
 movement. It is, therefore, not necessary to seek any other 
 origin for it than that of life itself of the organised being, which 
 feels only so far as it is moved, and which moves only as far as 
 it feels. In this case, it is conditionally true to say that the first 
 of all movements has been accompanied by desire or by will, 
 and that the instinctive determinations, being sensations as the 
 others, include judgment, desire, etc. The individual faculty 
 which is in question in the second point of view, far from being 
 subordinate to the sensibility, is most often in opposition to it; 
 and we have already seen that it has its peculiar and primor- 
 dial laws, outside the circle of all affective impressions. 
 
 The experience of the inner sense suffices to assure us in fact
 
 458 THE FOUNDATIONS OF PSYCHOLOGY 
 
 that, in the cases in which movements of any kind are com- 
 pelled and abruptly incited by violent appetites, passions, or 
 too emotional excitations of the sensibility, we ourselves move, 
 or rather our body moves without our leave, without, or even 
 against the explicit orders of the will, which is oppressed and 
 as it were nullified, by the very fact that sensibility predomin- 
 ates or rules exclusively. How could it therefore be possible 
 that the same affective impressions, which destroy the control 
 of the will, and absorb or hamper that power, even when it is 
 already fully established, would originally serve to develop 
 it and to set it in exercise? How is it possible to suppose that 
 the being, which begins to live, can perceive or feel its own 
 movements, and begin to derive therefrom some knowledge, 
 when we ourselves are completely ignorant alike of the cause 
 and of the effect of those movements, in the midst of the dis- 
 turbance of the affections which provoke or even prevail over 
 them? How finally could the very principle, which obscures 
 and so often extinguishes in us the light of consciousness, have 
 been the first source of it? 
 
 We are, therefore, justified in saying from our present stand- 
 point, that the first movements, which are determined by ap- 
 petite or organic need, or even accompanied by desire, differ 
 as much from will properly so-called, as the peculiar and direct 
 action exerted from a single centre differs from all sympathetic 
 reactions. Thus, the first acts of this nascent will, explained in 
 its principles, differ from the blind determinations of instinct, 
 which precedes them in the order of time, but without serving 
 them in their origin. There is then occasion to seek by an 
 explicit analysis of primitive facts, what is the order of progress 
 or of conditions which may have produced the first exercise of 
 the individual power of effort, and with it the first feeling of the 
 self ; that which is equivalent to asking what is the law, eithei 
 physiological or psychological, of the transition from instinctive 
 movements, to voluntary and free movements, accompanied 
 by effort. 
 
 As long as the organic centre, to which physiologists refer 
 motor determination, only reacts in consequence of the impres-
 
 MAINE DE BIRAN 459 
 
 sions which it receives from diverse sensitive organs with which 
 it is in relation, the movements thus produced, not being capa- 
 ble of being perceived or felt as distinct from their producing 
 causes, cannot even begin to be voluntary. For if distinct per- 
 ception is not anterior, as I believe, to any exercise whatever of 
 the will, neither can this latter in its turn precede any degree 
 whatsoever of perception; and although it may be true to say, 
 that the thinking being cannot begin to know save in so far as 
 he begins to act and to will, it is none the less true, in the ordin- 
 ary phrase, that one cannot expressly will that of which one 
 has no knowledge. 
 
 If one appears to revolve here in a vicious circle, the reason 
 is, that as a result of having failed to recognize the truly prim- 
 itive fact, one wishes to distinguish or separate two acts which 
 are reduced to one in this fact, and that one already applies the 
 law of succession, or like the Kantians, the complete form of 
 time, to the first term of every succession, at the origin of all 
 time. 
 
 Through the indeterminate order of the progress of being, 
 simple in the vital stage, but destined to become double in the 
 human stage, 1 a period arrives when the exclusive rule of instinct 
 tends to end or to be united to another order of faculties. Al- 
 ready the impressions begin to become less vivid, less general, 
 less tumultuous; habit has blunted their edge which was at first 
 strongly affective; the appetites are less pressing, the move- 
 ments less brusque, less automatic; the organs of locomotion 
 begin to harden, their special irritability diminishes; they yield 
 less promptly to every external cause of contraction. Thus, on 
 the one side, these organs have contracted habits in repeated 
 instinctive locomotion, and they are disposed in such way to 
 comply with more facility to the new contractions that the will 
 is to impose upon them; on the other hand, the motor centre 
 has also acquired in reacting such determinations that it is 
 capable of entering spontaneously into action, by virtue of that 
 general law of habit, in consequence of which a living organ 
 
 1 Homo simplex in vitalitate, duplex in humanitale, says Boerhaave energet- 
 ically, and with profound truth.
 
 460 THE FOUNDATIONS OF PSYCHOLOGY 
 
 tends to renew of itself the impressions or the movements 
 that a foreign cause has a number of times aroused in it, or in 
 consequence of which makes it own the dispositions of another 
 organ with which it has sympathetically shared. 
 
 When the centre thus accomplishes movements by its own 
 and initial action, the latter take a wholly different character, 
 and become spontaneous, instead of being instinctive as they 
 were at the outset. Now this spontaneity is still not the will, or 
 the power of effort, but it immediately precedes it. By virtue 
 of the spontaneity of action of the centre, which is the imme- 
 diate term or proper instrument of the hyperorganic force of the 
 soul, that force, which could neither perceive nor distinctly feel 
 the instructive movements, begins to feel the spontaneous 
 movements which no emotion troubles or disturbs. But it can- 
 not begin to feel them thus as produced by its immediate in- 
 strument, without appropriating to itself their power. As soon 
 as it feels that power, it exerts it by accomplishing that move- 
 ment itself. As soon as it effects it, it perceives its effort with 
 the resistance, it is a cause for itself, and in relation to the 
 effect that it produces, with freedom, it is the self. 
 
 Thus personality begins with the first complete action of a 
 hyperorganic force which is for itself, or as self, only in so far as 
 it knows itself, and which begins to know itself only in so far as 
 it begins to act with freedom. The problem is not to know 
 what that force is in itself, how it exists, or when it begins 
 absolutely to exist, but when it begins to exist as an identical 
 person, as self. Now it exists for itself only in so far as it knows 
 itself, and it knows itself only in so far as it acts. 
 
 Although the primitive fact, of which we seek to determine 
 the source, seems to escape, in that source itself, from every 
 kind of experiment, and presents itself only as an hypothesis, 
 we can nevertheless discover some examples adapted to explain, 
 up to a certain point, the origin of personality, such as we have 
 just established it. 
 
 i. In sleep of the mind or of the self, it occurs sometimes that 
 one is awakened with a start in consequence of movements, of 
 words or of voices, produced by a spontaneity resembling that
 
 MAINE DE BIRAN 461 
 
 which serves originally as intermediary between instinct and 
 will. At the very instant of this sudden awakening, the indi- 
 vidual feels these movements, not accompanied with effort as 
 they are in the state of waking, but with a feeling of power to 
 make them, which is, in this case, the memory of that effort. It 
 is in this way that he appropriates to himself in their result 
 those spontaneous movements that he has not determined in 
 their principle, and that conscious appropriation characterises 
 solely the perfect awakening. Therefore, in the origin of person- 
 ality, spontaneous movement awakens the soul, causes to arise 
 in it, as it were, the presentiment of a power which determines 
 the first voluntary effort, and with it the first knowledge. 
 
 2. In the newborn infant, and even during a certain period 
 after birth, the locomotion and voice are set in action only by 
 instinct. The infant frets and cries because it suffers, and in so 
 far as it is affected by simple needs or appetites. As long as 
 this purely sensitive state continues, will and apperception can- 
 not exist ; for how can you suppose that the first cries of pain, 
 the first automatic movements, are acts of a faculty of will and 
 of judgment already in exercise, unless you admit these faculties 
 as innate or unconditioned? Without doubt the cries of an 
 infant have a significance or a natural sense, but that is for an 
 intelligent being capable of understanding or of interpreting it, 
 and not for the infant reduced to sensations and to animal con- 
 tractions. But apart from the exclusive domain of the affec- 
 tions, of the needs or appetites of instinct, the infant still cries 
 and frets by virtue of the determinations or of the habits con- 
 tracted by the motor centre and by the organs of movement or 
 of the voice. These movements then spontaneous are veritable 
 sensations. Soon they will be perceived, willed and trans- 
 formed by the infant itself, into involuntary signs of which it will 
 make use in order to call for aid. Behold the first stage of man, 
 duplex in humanitate, the first sign of nascent personality. The 
 transition sought for is then accomplished. But how could it 
 have been possible, if the movements had always been the pro- 
 ducts of an instinctive and sympathetic reaction, carried away 
 k and repelled by vivid emotions, and finally if there had not
 
 462 THE FOUNDATIONS OF PSYCHOLOGY 
 
 been an intermediary mode of motility such, that sensation, 
 distinct from the movement performed, be accompanied by a 
 feeling of power, and gives rise consequently to the exercise of 
 the will? Such is the order or the series of progress; such 
 is the transition from instinct to spontaneity, and from that to 
 the will, which constitutes the person, the self. The animal 
 rapidly passes beyond the first two degrees; man alone can 
 attain to the third, but he attains it only progressively, accord- 
 ing to certain laws or conditions, that philosophy should seek 
 to know in order to find the principles and origin of science. If 
 we have not been able to dispel all the clouds which conceal 
 that origin, we have at least shown how, and in what sense, it is 
 necessary to admit an assignable origin of personality; how or 
 by what procedure of analysis, one can hope to find it identi- 
 fied, not with the first sensation of a passive substance, but with 
 the first action of a hyperorganic force.
 
 JAMES MILL 
 
 (1773-1836) 
 
 ANALYSIS OF THE PHENOMENA OF THE 
 HUMAN MIND* 
 
 CHAPTER III. THE ASSOCIATION OF IDEAS 
 
 "To have a clear view of the phenomena of the mind, as mere affections or 
 states of it, existing successively, and in a certain series, which we are able, there- 
 fore, to predict, in consequence of our knowledge of the past, is, I conceive, to have 
 made the most important acquisition which the intellectual inquirer can make." 
 
 Brown, Lectures, i. 544. 
 
 THOUGHT succeeds thought; idea follows idea, incessantly. 
 If our senses are awake, we are continually receiving sensa- 
 tions, of the eye, the ear, the touch, and so forth ; but not sensa- 
 tions alone. After sensations, ideas are perpetually excited of 
 sensations formerly received; after those ideas, other ideas: and 
 during the whole of our lives, a series of those two states of con- 
 sciousness, called sensations, and ideas, is constantly going on. 
 I see a horse: that is a sensation. Immediately I think of his 
 master: that is an idea. The idea of his master makes me think 
 of his office; he is a minister of state: that is another idea. The 
 idea of a minister of state makes me think of public affairs ; and 
 I am led into a train of political ideas; when I am summoned to 
 dinner. This is a new sensation, followed by the idea of dinner, 
 and of the company with whom I am to partake it. The sight 
 of the company and of the food are other sensations; these sug- 
 gest ideas without end ; other sensations perpetually intervene, 
 suggesting other ideas : and so the process goes on. 
 
 In contemplating this train of feelings, of which our lives 
 consist, it first of all strikes the contemplator, as of importance 
 
 * London, 1829; new ed., with notes illustrative and critical by Alexander 
 Bain, Andrew Findlater, and George Grote, edited with additional notes by John 
 Stuart Mill, ib. 1869, vol. i.
 
 464 JAMES MILL 
 
 to ascertain, whether they occur casually and irregularly, or 
 according to a certain order. 
 
 With respect to the SENSATIONS, it is obvious enough that 
 they occur, according to the order established among what we 
 call the objects of nature, whatever those objects are; to ascer- 
 tain more and more of which order is the business of physical 
 philosophy in all its branches. 
 
 Of the order established among the objects of nature, by 
 which we mean the objects of our senses, two remarkable cases 
 are all which here we are called upon to notice; the SYNCHRON- 
 OUS ORDER and the SUCCESSIVE ORDER. The synchronous order, 
 or order of simultaneous existence, is the order in space; the 
 successive order, or order of antecedent and consequent exist- 
 ence, is the order in time. Thus the various objects in my 
 room, the chairs, the tables, the books, have the synchronous 
 order, or order in space. The falling of the spark, and the ex- 
 plosion of the gunpowder, have the successive order, or order 
 in time. 
 
 According to this order, in the objects of sense, there is a 
 synchronous, and a successive, order of our sensations. I have 
 SYNCHRONICALLY, or at the same instant, the sight of a great 
 variety of objects; touch of all the objects with which my body 
 is in contact; hearing of all the sounds which are reaching my 
 ears ; smelling of all the smells which are reaching my nostrils ; 
 taste of the apple which I am eating; the sensation of resistance 
 both from the apple which is in my mouth, and the ground on 
 which I stand; with the sensation of motion from the act of 
 walking. I have SUCCESSIVELY the sight of the flash from the 
 mortar fired at a distance, the hearing of the report, the sight 
 of the bomb, and of its motion in the air, the sight of its fall, the 
 sight and hearing of its explosion, and lastly, the sight of all the 
 effects of that explosion. 
 
 Among the objects which I have thus observed synchron- 
 ically, or successively; that is, from which I have had synchron- 
 ical or successive sensations; there are some which I have so 
 observed frequently; others which I have so observed not fre- 
 quently: in other words, of my sensations some have been fre-
 
 PHENOMENA OF THE HUMAN MIND 465 
 
 quently synchronical, others not frequently; some frequently 
 successive, others not frequently. Thus, my sight of roast beef, 
 and my taste of roast beef, have been frequently SYNCHRONICAL; 
 my smell of a rose, and my sight and touch of a rose, have been 
 frequently synchronical; my sight of a stone, and my sensa- 
 tions of its hardness, and weight, have been frequently syn- 
 chronical. Others of my sensations have not been frequently 
 synchronical: my sight of a lion, and the hearing of his roar; 
 my sight of a knife, and its stabbing a man. My sight of the 
 flash of lightning, and my hearing of the thunder, have been 
 often SUCCESSIVE; the pain of cold, and the pleasure of heat, 
 have been often successive; the sight of a trumpet, and the 
 sound of a trumpet, have been often successive. On the other 
 hand, my sight of hemlock, and my taste of hemlock, have not 
 been often successive: and so on. 
 
 It so happens, that, of the objects from which we derive the 
 greatest part of our sensations, most of those which are ob- 
 served synchronically, are frequently observed synchronically; 
 most of those which are observed successively, are frequently 
 observed successively. In other words, most of our synchron- 
 ical sensations, have been frequently synchronical; most of our 
 successive sensations, have been frequently successive. Thus, 
 most of our synchronical sensations are derived from the objects 
 around us, the objects which we have the most frequent occa- 
 sion to hear and see; the members of our family; the furniture 
 of our houses; our food; the instruments of our occupations or 
 amusements. In like manner, of those sensations which we 
 have had in succession, we have had the greatest number 
 repeatedly in succession; the sight of fire, and its warmth; the 
 touch of snow, and its cold; the sight of food, and its taste. 
 
 Thus much with regard to the order of SENSATIONS; next 
 with regard to the order of IDEAS. 
 
 As ideas are not derived from objects, we should not expect 
 their order to be derived from the order of objects; but as they 
 are derived from sensations, we might by analogy expect, that 
 they would derive their order from that of the sensations; and 
 this to a great extent is the case.
 
 466 JAMES MILL 
 
 Our ideas spring up, or exist, in the order in which the sensa- 
 tions existed, of which they are the copies. 
 
 This is the general law of the "Association of Ideas"; by 
 which term, let it be remembered, nothing is here meant to be 
 expressed, but the order of occurrence. 
 
 In this law, the following things are to be carefully observed. 
 
 1. Of those sensations which occurred synchronically, the 
 ideas also spring up synchronically. I have seen a violin, and 
 heard the tones of the violin, synchronically. If I think of the 
 tones of the violin, the visible appearance of the violin at the 
 same time occurs to me. I have seen the sun, and the sky in 
 which it is placed, synchronically. If I think of the one, I think 
 of the other at the same time. 
 
 One of the cases of synchronical sensation, which deserves 
 the most particular attention, is, that of the several sensations 
 derived from one and the same object; a stone, for example, 
 a flower, a table, a chair, a horse, a man. 
 
 From a stone I have had, synchronically, the sensation of 
 colour, the sensation of hardness, the sensations of shape, and 
 size, the sensation of weight. When the idea of one of these 
 sensations occurs, the ideas of all of them occur. They exist in 
 my mind synchronically; and their synchronical existence is 
 called the idea of the stone; which, it is thus plain, is not a single 
 idea, but a number of ideas in a particular state of combina- 
 tion. 
 
 Thus, again, I have smelt a rose, and looked at, and handled 
 a rose, synchronically; accordingly the name rose suggests to 
 me all those ideas synchronically ; and this combination of those 
 simple ideas is called my idea of the rose. 
 
 My idea of an animal is still more complex. The word thrush, 
 for example, not only suggests an idea of a particular colour and 
 shape, and size, but of song, and flight, and nestling, and eggs, 
 and callow young, and others. 
 
 My idea of a man is the most complex of all; including not 
 only colour, and shape, and voice, but the whole class of events 
 in which I have observed him either the agent or the patient. 
 
 2. As the ideas of the sensations which occurred synchron-
 
 PHENOMENA OF THE HUMAN MIND 467 
 
 ically, rise synchronically, so the ideas of the sensations which 
 occurred successively, rise successively. 
 
 Of this important case of association, or of the successive 
 order of our ideas, many remarkable instances might be ad- 
 duced. Of these none seems better adapted to the learner than 
 the repetition of any passage, or words; the Lord's Prayer, for 
 example, committed to memory. In learning the passage, we 
 repeat it; that is, we pronounce the words, in successive order, 
 from the beginning to the end. The order of the sensations is 
 successive. When we proceed to repeat the passage, the ideas 
 of the words also rise in succession, the preceding always sug- 
 gesting the succeeding, and no other. Our suggests Father, 
 Father suggests which, which suggests art; and so on, to the end. 
 How remarkably this is the case, any one may convince him- 
 self, by trying to repeat backwards, even a passage with which 
 he is as familiar as the Lord's Prayer. The case is the same 
 with numbers. A man can go on with the numbers in the pro- 
 gressive order, one, two, three, &c. scarcely thinking of his act; 
 and though it is possible for him to repeat them backward, be- 
 cause he is accustomed to subtraction of numbers, he cannot do 
 so without an effort. 
 
 Of witnesses in courts of justice it has been remarked, that 
 eye-witnesses, and ear-witnesses, always tell their story in the 
 chronological order; in other words, the ideas occur to them in 
 the order in which the sensations occurred; on the other hand, 
 that witnesses, who are inventing, rarely adhere to the chrono- 
 logical order. 
 
 3. A far greater number of our sensations are received in the 
 successive, than in the synchronical order. Of our ideas, also, 
 the number is infinitely greater that rise in the successive than 
 the synchronical order. 
 
 4. In the successive order of ideas, that which precedes, is 
 sometimes called the suggesting, that which succeeds, the sug- 
 gested idea ; not that any power is supposed to reside in the ante- 
 cedent over the consequent; suggesting, and suggested, mean 
 only antecedent and consequent, with the additional idea, that 
 such order is not casual, but, to a certain degree, permanent.
 
 4 68 JAMES MILL 
 
 5. Of the antecedent and consequent feelings, or the suggest- 
 ing, and suggested; the antecedent may be either sensations or 
 ideas; the consequent are always ideas. An idea may be excited 
 either by a sensation or an idea. The sight of the dog of my 
 friend is a sensation, and it excites the idea of my friend. The 
 idea of Professor Dugald Stewart delivering a lecture, recalls 
 the idea of the delight with which I heard him ; that, the idea 
 of the studies in which it engaged me; that, the trains of thought 
 which succeeded; and each epoch of my mental history, the 
 succeeding one, till the present moment; in which I am en- 
 deavouring to present to others what appears to me valuable 
 among the innumerable ideas of which this lengthened train 
 has been composed. 
 
 6. As there are degrees in sensations, and degrees in ideas; for 
 one sensation is more vivid than another sensation, one idea 
 more vivid than another idea; so there are degrees in associa- 
 tion. One association, we say, is stronger than another: First, 
 when it is more permanent than another: Secondly, when it is 
 performed with more certainty: Thirdly, when it is performed 
 with more facility. 
 
 It is well known, that some associations are very transient, 
 others very permanent. The case which we formerly men- 
 tioned, that of repeating words committed to memory, affords 
 an apt illustration. In some cases, we can perform the repeti- 
 tion, when a few hours, or a few days have elapsed; but not 
 after a longer period. In others, we can perform it after the 
 lapse of many years. There are few children in whose minds 
 some association has not been formed between darkness and 
 ghosts. In some this association is soon dissolved; in some it 
 continues for life. 
 
 In some cases the association takes place with less, in some 
 with greater certainty. Thus, in repeating words, I am not 
 sure that I shall not commit mistakes, if they are imperfectly 
 got; and I may at one trial repeat them right, at another 
 wrong: I am sure of always repeating those correctly, which I 
 have got perfectly. Thus, in my native language, the associa- 
 tion between the name and the thing is certain; in a language
 
 PHENOMENA OF THE HUMAN MIND 469 
 
 with which I am imperfectly acquainted, not certain. In ex- 
 pressing myself in my own language, the idea of the thing sug- 
 gests the idea of the name with certainty. In speaking a lan- 
 guage with which I am imperfectly acquainted, the idea of the 
 thing does not with certainty suggest the idea of the name; at 
 one time it may, at another not. 
 
 That ideas are associated in some cases with more, in some 
 with less facility, is strikingly illustrated by the same instance, 
 of a language with which we are well, and a language with 
 which we are imperfectly, acquainted. In speaking our own 
 language, we are not conscious of any effort; the associations 
 between the words and the ideas appear spontaneous. In 
 endeavouring to speak a language with which we are im- 
 perfectly acquainted, we are sensible of a painful effort : the 
 associations between the words and ideas being not ready, or 
 immediate. 
 
 7. The causes of strength in association seem all to be re- 
 solvable into two; the vividness of the associated feelings; and 
 the frequency of the association. 
 
 In general, we convey not a very precise meaning, when we 
 speak of the vividness of sensations and ideas. We may be 
 understood when we say that, generally speaking, the sensation 
 is more vivid than the idea; or the primary, than the secondary 
 feeling; though in dreams, and in delirium, ideas are mistaken 
 for sensations. But when we say that one sensation is more 
 vivid than another, there is much more uncertainty. We can 
 distinguish those sensations which are pleasurable, and those 
 which are painful, from such as are not so; and when we call the 
 pleasurable and painful more vivid, than those which are not 
 so, we speak intelligibly. We can also distinguish degrees of 
 pleasure, and of pain; and when we call the sensation of the 
 higher degree more vivid than the sensation of the lower 
 degree, we may again be considered as expressing a meaning 
 tolerably precise. 
 
 In calling one IDEA more vivid than another, if we confine the 
 appellation to the ideas of such SENSATIONS as may with preci- 
 sion be called more or less vivid ; the sensations of pleasure and
 
 470 JAMES MILL 
 
 pain, in their various degrees, compared with sensations which 
 we do not call either pleasurable or painful ; our language will 
 still have a certain degree of precision. But what is the meaning 
 which I annex to my words, when I say, that my idea of the 
 taste of the pine-apple which I tasted yesterday is vivid; my 
 idea of the taste of the foreign fruit which I never tasted but 
 once in early life, is not vivid? If I mean that I can more cer- 
 tainly distinguish the more recent, than the more distant sensa- 
 tion, there is still some precision in my language; because it 
 seems true of all my senses, that if I compare a distant sensa- 
 tion with the present, I am less sure of its being or not being a 
 repetition of the same, than if I compare a recent sensation 
 with a present one. Thus, if I yesterday had a smell of a very 
 peculiar kind, and compare it with a present smell, I can judge 
 more accurately of the agreement or disagreement of the two 
 sensations, than if I compared the present with one much more 
 remote. The same is the case with colours, with sounds, with 
 feelings of touch, and of resistance. It is therefore sufficiently 
 certain, that the idea of the more recent sensation affords the 
 means of a more accurate comparison, generally, than the idea 
 of the more remote sensation. And thus we have three cases 
 
 * 
 
 of vividness, of which we can speak with some precision: the 
 case of sensations, as compared with ideas ; the case of pleas- 
 urable and painful sensations, and their ideas as compared 
 v 'th those which are not pleasurable or painful; and the case of 
 the more recent, compared with the more remote. 
 
 That the association of two ideas, but for once, does, in some 
 cases, give them a very strong connection, is within the sphere 
 of every man's experience. The most remarkable cases are 
 probably those of pain and pleasure. Some persons who have 
 experienced a very painful surgical operation, can never after- 
 wards bear the sight of the operator, however strong the grati- 
 tude which they may actually feel towards him. The meaning 
 is, that the sight of the operator, by a strong association, calls 
 up so vividly the idea of the pain of the operation, that it is 
 itself a pain. The spot on which a tender maiden parted with 
 her lover, when he embarked on the voyage from which he
 
 PHENOMENA OF THE HUMAN MIND 471 
 
 never returned, cannot afterwards be seen by her without an 
 agony of grief. 
 
 These cases, also, furnish an apt illustration of the superior- 
 ity which the sensation possesses over the idea, as an associating 
 cause. Though the sight of the surgeon, the sight of the place, 
 would awaken the ideas which we have described, the mere 
 thought of them might be attended with no peculiar effect. 
 Those persons who have the association of frightful objects with 
 darkness, and who are transported with terrors when placed in 
 the dark, can still think of darkness without any emotion. 
 
 The same cases furnish an illustration of the effect of recency 
 on the strength of association. The sight, of the affecting spot 
 by the maiden, of the surgeon by the patient, would certainly 
 produce a more intense emotion, after a short, than after a long 
 interval. With most persons, time would weaken, and at last 
 dissolve, the association. 
 
 So much with regard to vividness, as a cause of strong asso- 
 ciations. Next, we have to consider frequency or repetition; 
 which is the most remarkable and important cause of the 
 strength of our associations. 
 
 Of any two sensations, frequently perceived together, the 
 ideas are associated. Thus, at least, in the minds of English- 
 men, the idea of a soldier, and the idea of a red coat are asso- 
 ciated ; the idea of a clergyman, and the idea of a black coat; the 
 idea of a quaker, and of a broad-brimmed hat; the idea of a 
 woman and the idea of petticoats. A peculiar taste suggests 
 the idea of an apple; a peculiar smell the idea of a rose. If I 
 have heard a particular air frequently sung by a particular per- 
 son, the hearing of the air suggests the idea of the person. 
 
 The most remarkable exemplification of the effect of degrees 
 of frequency, in producing degrees of strength in the associa- 
 tions, is to be found in the cases in which the association is pur- 
 posely and studiously contracted; the cases in which we learn 
 something; the use of words, for example. 
 
 Every child learns the language which is spoken by those 
 around him. He also learns it by degrees. He learns first the 
 names of the most familiar objects; and among familiar objects,
 
 472 JAMES MILL 
 
 the names of those which he most frequently has occasion to 
 name; himself, his nurse, his food, his playthings. 
 
 A sound heard once in conjunction with another sensation; 
 the word mamma, for example, with the sight of a woman, 
 would produce no greater effect on the child, than the conjunc- 
 tion of any other sensation, which once exists and is gone for- 
 ever. But if the word mamma is frequently pronounced, in 
 conjunction with the sight of a particular woman, the sound 
 will by degrees become associated with the sight; and as the 
 pronouncing of the name will call up the idea of the woman, so 
 the sight of the woman will call up the idea of the name. 
 
 The process becomes very perceptible to us, when, at years 
 of reflection, we proceed to learn a dead or foreign language. At 
 the first lesson, we are told, or we see in the dictionary, the 
 meaning of perhaps twenty words. But it is not joining the 
 word and its meaning once, that will make the word suggest its 
 meaning to us another time. We repeat the two in conjunction, 
 till we think the meaning so well associated with the word, 
 that whenever the word occurs to us, the meaning will occur 
 along with it. We are often deceived in this anticipation; and 
 finding that the meaning is not suggested by the word, we have 
 to renew the process of repetition, and this, perhaps, again, and 
 again. By force of repetition the meaning is associated, at 
 last, with every word of the language, and so perfectly, that 
 the one never occurs to us without the other. 
 
 Learning to play on a musical instrument is another remark- 
 able illustration of the effect of repetition in strengthening 
 associations, in rendering those sequences, which, at first, are 
 slow, and difficult, afterwards, rapid, and easy. At first, the 
 learner, after thinking of each successive note, as it stands in 
 his book, has each time to look out with care for the key or the 
 string which he is to touch, and the finger he is to touch it with, 
 and is every moment committing mistakes. Repetition is well 
 known to be the only means of overcoming these difficulties. 
 As the repetition goes on, the sight of the note, or even the idea 
 of the note, becomes associated with the place of the key or the 
 string; and that of the key or the string with the proper finger.
 
 473 
 
 The association for a time is imperfect, but at last becomes so 
 strong, that it is performed with the greatest rapidity, without 
 an effort, and almost without consciousness. 
 
 In few cases is the strength of association, derived from repe- 
 tition, more worthy of attention, than in performing arithme- 
 tic. All men, whose practice is not great, find the addition of a 
 long column of numbers, tedious, and the accuracy of the oper- 
 ation, by no means certain. Till a man has had considerable 
 practice, there are few acts of the mind more toilsome. The 
 reason is, that the names of the numbers, which correspond to 
 the different steps, do not readily occur; that is, are not 
 strongly associated with the names which precede them. Thus, 
 7 added to 5, make 12; but the antecedent, 7 added to 5, is not 
 strongly associated with the consequent 12, in the mind of the 
 learner, and he has to wait and search till the name occurs. 
 Thus, again, 12 and 7 make 19; 19 and 8 make 27, and so on to 
 any amount; but if the practice of the performer has been small, 
 the association in each instance is imperfect, and the process 
 irksome and slow. Practice, however; that is, frequency of 
 repetition ; makes the association between each of these antece- 
 dents and its proper consequent so perfect, that no sooner is the 
 one conceived than the other is conceived, and an expert arith- 
 metician can tell the amount of a long column of figures, with a 
 rapidity, which seems almost miraculous to the man whose 
 faculty of numeration is of the ordinary standard. 
 
 8. Where two or more ideas have been often repeated to- 
 gether, and the association has become very strong, they 
 sometimes spring up in such close combination as not to be 
 distinguishable. Some cases of sensation are analogous. For 
 example; when a wheel, on the seven parts of which the seven 
 prismatic colours are respectively painted, is made to revolve 
 rapidly, it appears not of seven colours, but of one uniform 
 colour, white. By the rapidity of the succession, the several 
 sensations cease to be distinguishable; they run, as it were, 
 together, and a new sensation, compounded of all the seven, 
 but apparently a simple one, is the result. Ideas, also, which 
 have been so often conjoined, that whenever one exists in the
 
 474 JAMES MILL 
 
 mind, the others immediately exist along with it, seem to run 
 into one another, to coalesce, as it were, and out of many to 
 form one idea; which idea, however in reality complex, appears 
 to be no less simple, than any one of those of which it is com- 
 pounded. 
 
 The word gold, for example, or the word iron, appears to 
 express as simple an idea, as the word colour, or the word 
 sound. Yet it is immediately seen, that the idea of each of those 
 metals is made up of the separate ideas of several sensations; 
 colour, hardness, extension, weight. Those ideas, however, 
 present themselves in such intimate union, that they are con- 
 stantly spoken of as one, not many. We say, our idea of iron, 
 our idea of gold; and it is only with an effort that reflecting 
 men perform the decomposition. 
 
 The idea expressed by the term weight, appears so perfectly 
 simple, that he is a good metaphysician, who can trace its com- 
 position. Yet it involves, of course, the idea of resistance, 
 which we have shewn above to be compounded, and to involve 
 the feeling attendant upon the contraction of muscles; and the 
 feeling, or feelings, denominated Will ; it involves the idea, not 
 of resistance simply, but of resistance in a particular direction; 
 the idea of direction, therefore, is included in it, and in that are 
 involved the ideas of extension, and of place and motion, some 
 of the most complicated phenomena of the human mind. 
 
 The ideas of hardness and extension have been so uniformly 
 regarded as simple, that the greatest metaphysicians have set 
 them down as the copies of simple sensations of touch. Hartley 
 and Darwin, were, I believe, the first who thought of assigning 
 to them a different origin. 
 
 We call a thing hard, because it resists compression, or sepa- 
 ration of parts; that is, because to compress it, or separate it 
 into parts, what we call muscular force is required. The idea, 
 then, of muscular action, and of all the feelings which go to it, 
 are involved in the idea of hardness. 
 
 The idea of extension is derived from the muscular feelings in 
 what we call the motion of parts of our own bodies; as for exam- 
 ple, the hands. I move my hand along a line; I have certain
 
 PHENOMENA OF THE HUMAN MIND 475 
 
 sensations; on account of these sensations, I call the line long, 
 or extended. The idea of lines in the direction of length, breadth, 
 and thickness, constitutes the general idea of extension. In the 
 idea of extension, there are included three of the most complex 
 of our ideas; motion; time, which is included in motion; and 
 space, which is included in direction. We are not yet prepared 
 to explain the simple ideas which compose the very complex 
 ideas, of motion, space, and time; it is enough at present to 
 have shewn, that in the idea of extension, which appears so very 
 simple, a great number of ideas are nevertheless included; and 
 that this is a case of that combination of ideas in the higher 
 degrees of association, in which the simple ideas are so inti- 
 mately blended, as to have the appearance, not of a complex, 
 but of a simple idea. 
 
 It is to this great law of association, that we trace the forma- 
 tion of our ideas of what we call external objects; that is, the 
 ideas of a certain number of sensations, received together so 
 frequently that they coalesce as it. were, and are spoken of 
 under the idea of unity. Hence, what we call the idea of a tree, 
 the idea of a stone, the idea of a horse, the idea of a man. 
 
 In using the names, tree, horse, man, the names of what I 
 call objects, I am referring, and can be referring, only to my 
 own sensations; in fact, therefore, only naming a certain num- 
 ber of sensations, regarded as in a particular state of combina- 
 tion; that is, concomitance. Particular sensations of sight, of 
 touch, of the muscles, are the sensations, to the ideas of which, 
 colour, extension, roughness, hardness, smoothness, taste, 
 smell, so coalescing as to appear one idea, I give the name, idea 
 of a tree. 
 
 To this case of high association, this blending together of 
 many ideas, in so close a combination that they appear not 
 many ideas, but one idea, we owe, as I shall afterwards more 
 fully explain, the power of classification, and all the advan- 
 tages of language. It is obviously, therefore, of the greatest 
 moment, that this important phenomenon should be well 
 understood. 
 
 9. Some ideas are by frequency and strength of association
 
 476 JAMES MILL 
 
 so closely combined, that they cannot be separated. If one 
 exists, the others exist along with it, in spite of whatever effort 
 we make to disjoin them. 
 
 For example; it is not in our power to think of colour, with- 
 out thinking of extension; or of solidity, without figure. We 
 have seen colour constantly in combination with extension, 
 spread as it were, upon a surface. We have never seen it except 
 in this connection. Colour and extension have been invariably 
 conjoined. The idea of colour, therefore, uniformly comes into 
 the mind, bringing that of extension along with it; and so 
 close is the association, that it is not in our power to dissolve 
 it. We cannot, if we will, think of colour, but in combination 
 with extension. The one idea calls up the other, and retains 
 it, so long as the other is retained. 
 
 This great law of our nature is illustrated in a manner 
 equally striking, by the connection between the ideas of solidity 
 and figure. We never have the sensations from which the idea 
 of solidity is derived, but jn conjunction with the sensations 
 whence the idea of figure is derived. If we handle anything 
 solid, it is always either round, square, or of some other form. 
 The ideas correspond with the sensations. If the idea of solidity 
 rises, that of figure rises along with it. The idea of figure which 
 rises, is, of course, more obscure than that of extension; be- 
 cause, figures being innumerable, the general idea is exceed- 
 ingly complex, and hence, of necessity, obscure. But, such as it 
 is, the idea of figure is always present when that of solidity is 
 present; nor can we, by any effort, think of the one without 
 thinking of the other at the same time. 
 
 Of all the cases of this important law of association, there is 
 none more extraordinary than what some philosophers have 
 called, the acquired perceptions of sight. 
 
 When I lift my eyes from the paper on which I am writing, 
 I see the chairs, and tables, and walls of my room, each of its 
 proper shape, and at its proper distance. I see, from my win- 
 dow, trees, and meadows, and horses, and oxen, and distant 
 hills. I see each of its proper size, of its proper form, and at its 
 proper distance; and these particulars appear as immediate
 
 PHENOMENA OF THE HUMAN MIND 477 
 
 informations of the eye, as the colours which I see by means of 
 it. 
 
 Yet, philosophy has ascertained, that we derive nothing from 
 the eye whatever, but sensations of colour; that the idea of 
 extension, in which size, and form, and distance are included, is 
 derived from sensations, not in the eye, but in the muscular 
 part of our frame. How, then, is it, that we receive accurate 
 information, by the eye, of size, and shape, and distance? By 
 association merely. 
 
 The colours upon a body are different, according to its figure, 
 its distance, and its size. But the sensations of colour, and what 
 we may here, for brevity, call the sensations of extension, of 
 figure, of distance, have been so often united, felt in conjunc- 
 tion, that the sensation of the colour is never experienced with- 
 out raising the ideas of the extension, the figure, the distance, 
 in such intimate union with it, that they not only cannot be 
 separated, but are actually supposed to be seen. The sight, as 
 it is called, of figure, or distance, appearing, as it does, a simple 
 sensation, is in reality a complex state of consciousness; a 
 sequence, in which the antecedent, a sensation of colour, and 
 the consequent, a number of ideas, are so closely combined by 
 association, that they appear not one idea, but one sensation. 
 
 Some persons, by the folly of those about them, in early life, 
 have formed associations between the sound of thunder, and 
 danger to their lives. They are accordingly in a state of agita- 
 tion during a thunder storm. The sound of the thunder calls up 
 the idea of danger, and no effort they can make, no reasoning 
 they can use with themselves, to show how small the chance 
 that they will be harmed, empowers them to dissolve the spell, 
 to break the association, and deliver themselves from the tor- 
 menting idea, while the sensation or the expectation of it 
 remains. 
 
 Another very familiar illustration may be adduced. Some 
 persons have what is called an antipathy to a spider, a toad, or 
 a rat. These feelings generally originate in some early fright. 
 The idea of danger has been on some occasion so intensely 
 excited along with the touch or sight of the animal, and hence
 
 478 JAMES MILL 
 
 the association so strongly formed, that it cannot be dissolved. 
 The sensation, in spite of them, excites the idea, and produces 
 the uneasiness which the idea imports. 
 
 The following of one idea after another idea, or after a sensa- 
 tion, so certainly that we cannot prevent the combination, nor 
 avoid having the consequent feeling as often as we have the 
 antecedent, is a law of association, the operation of which we 
 shall afterwards find to be extensive, and bearing a principal 
 part in some of the most important phenomena of the human 
 mind. 
 
 As there are some ideas so intimately blended by association, 
 that it is not in our power to separate them; there seem to be 
 others, which it is not in our power to combine. Dr. Brown, in 
 exposing some errors of his predecessors, with respect to the 
 acquired perceptions of sight, observes: "I cannot blend my 
 notions of the two surfaces, a plane, and a convex, as one sur- 
 face, both plane and convex, more than I can think of a whole 
 which is less than a fraction of itself, or a square of which the 
 sides are not equal." The case, here, appears to be, that a 
 strong association excludes whatever is opposite to it. I cannot 
 associate the two ideas of assafcetida, and the taste of sugar. 
 Why? Because the idea of assafcetida is so strongly associated 
 with the idea of another taste, that the idea of that other 
 taste rises in combination with the idea of assafcetida, and of 
 course the idea of sugar does not rise. I have one idea associ- 
 ated with the word pain. Why can I not associate pleasure 
 with the word pain? Because another indissoluble association 
 springs up, and excludes it. This is, therefore, only a case of 
 indissoluble association; but one of much importance, as we 
 shall find when we come to the exposition of some of the more 
 .complicated of our mental phenomena. 
 
 10. It not unfrequently happens in our associated feelings, 
 that the antecedent is of no importance farther than it intro- 
 duces the consequent. In these cases, the consequent absorbs 
 all the attention, and the antecedent is instantly forgotten. Of 
 this a very intelligible illustration is afforded by what happens 
 in ordinary discourse. A friend arrives from a distant country,
 
 PHENOMENA OF THE HUMAN MIND 479 
 
 and brings me the first intelligence of the last illness, the last 
 words, the last acts, and death of my son. The sound of the 
 voice, the articulation of every word, makes its sensation in my 
 ear; but it is to the ideas that my attention flies. It is my son 
 that is before me, suffering, acting, speaking, dying. The 
 words which have introduced the ideas, and kindled the affec- 
 tions, have been as little heeded, as the respiration which has 
 been accelerated, while the ideas were received. 
 
 It is important in respect to this case of association to 
 remark, that there are large classes of our sensations, such as 
 many of those in the alimentary duct, and many in the nervous 
 and vascular systems, which serve, as antecedents, to introduce 
 ideas, as consequents; but as the consequents are far more 
 interesting than themselves, and immediately absorb the atten- 
 tion, the antecedents are habitually overlooked; and though 
 they exercise, by the trains which they introduce, a great influ- 
 ence on our happiness or misery, they themselves are generally 
 wholly unknown. 
 
 That there are connections between our ideas and certain 
 states of the internal organs, is proved by many familiar in- 
 stances. Thus, anxiety, in most people, disorders the digestion. 
 It is no wonder, then, that the internal feelings which accom- 
 pany indigestion, should excite the ideas which prevail in a 
 state of anxiety. Fear, in most people, accelerates, in a remark- 
 able manner, the vermicular motion of the intestines. There is 
 an association, therefore, between certain states of the intes- 
 tines, and terrible ideas; and this is sufficiently confirmed by 
 the horrible dreams to which men are subject from indigestion ; 
 and the hypochondria, more or less afflicting, which almost 
 always accompanies certain morbid states of the digestive 
 organs. The grateful food which excites pleasurable sensations 
 in the mouth, continues them in the stomach; and, as pleasures 
 excite ideas of their causes, and these of similar causes, and 
 causes excite ideas of their effects, and so on, trains of pleas- 
 urable ideas take their origin from pleasurable sensations in 
 the stomach. Uneasy sensations in the stomach, produce 
 analogous effects. Disagreeable sensations are associated with
 
 4 8o JAMES MILL 
 
 
 
 disagreeable circumstances; a train is introduced, in which, one 
 painful idea following another, combinations, to the last degree 
 afflictive, are sometimes introduced, and the sufferer is alto- 
 gether overwhelmed by dismal associations. 
 
 In illustration of the fact, that sensations and ideas, which 
 are essential to some of the most important operations of our 
 minds, serve only as antecedents to more important conse- 
 quents, and are themselves so habitually overlooked, that their 
 existence is unknown, we may recur to the remarkable case 
 which we have just explained, of the ideas introduced by the 
 sensations of sight. The minute gradations of colour, which 
 accompany varieties of extension, figure, and distance, are 
 insignificant. The figure, the size, the distance, themselves, on 
 the other hand, are matters of the greatest importance. The 
 first having introduced the last, their work is done. The conse- 
 quents remain the sole objects of attention, the antecedents are 
 forgotten; in the present instance, not completely; in other 
 instances, so completely, that they cannot be recognized. 
 
 ii. Mr. Hume, and after him other philosophers, have said 
 that our ideas are associated according to three principles; 
 Contiguity in time and place, Causation, and Resemblance. 
 The Contiguity in time and place, must mean, that of the sen- 
 sations; and so far it is affirmed, that the order of the ideas fol- 
 lows that of the sensations. Contiguity of two sensations in 
 time, means the successive order. Contiguity of two sensations 
 in place, means the synchronous order. We have explained the 
 mode in which ideas are associated, in the synchronous, as well 
 as the successive order, and have traced the principle of con- 
 tiguity to its proper source. 
 
 Causation, the second of Mr. Hume's principles, is the same 
 with contiguity in time, or the order of succession. Causation 
 is only a name for the order established between an antecedent 
 and a consequent; that is, the established or constant antece- 
 dence of the one, and consequence of the other. Resemblance 
 only remains, as an alleged principle of association, and it is 
 necessary to inquire whether it is included in the laws which 
 have been above expounded. I believe it will be found that we
 
 PHENOMENA OF THE HUMAN MIND 481 
 
 are accustomed to see like things together. When we see a tree, 
 we generally see more trees than one; when we see an ox, we 
 generally see more oxen than one; a sheep, more sheep than 
 one; a man, more men than one. From this observation, I 
 think, we may refer resemblance to the law of frequency, of 
 which it seems to form only a particular case. 
 
 Mr. Hume makes contrast a principle of association, but not 
 a separate one, as he thinks it is compounded of Resemblance 
 and Causation. It is not necessary for us to show that this is an 
 unsatisfactory account of contrast. It is only necessary to 
 observe, that, as a case of association, it is not distinct from 
 those which we have above explained. 
 
 A dwarf suggests the idea of a giant. How? We call a dwarf 
 a dwarf, because he departs from a certain standard. We call a 
 giant a giant, because he departs from the same standard. This 
 is a case, therefore, of resemblance, that is, of frequency. 
 
 Pain is said to make us think of pleasure; and this is con- 
 sidered a case of association by contrast. There is no doubt 
 that pain makes us think of relief from it; because they have 
 been conjoined, and the great vividness of the sensations makes 
 the association strong. Relief from pain is a species of pleasure; 
 and one pleasure leads to think of another, from the resem- 
 blance. This is a comp'ound case, therefore, of vividness and 
 frequency. All other cases of contrast, I believe, may be ex- 
 pounded in a similar manner. 
 
 I have not thought it necessary to be tedious in expounding 
 the observations which I have thus stated; for whether the 
 reader supposes that resemblance is, or is not, an original prin- 
 ciple of association, will not affect our future investigations. 
 
 12. Not only do simple ideas, by strong association, run 
 together, and form complex- ideas: but a complex idea, when 
 the simple ideas which compose it have become so consolidated 
 that it always appears as one, is capable of entering into com- 
 binations with other ideas, both simple and complex. Thus two 
 complex ideas may be united together, by a strong association, 
 and coalesce into one, in the same manner as two or more sim- 
 ple ideas coalesce into one. This union of two complex ideas
 
 482 JAMES MILL 
 
 into one, Dr. Hartley has called a duplex idea. Two also of 
 these duplex, or doubly compounded ideas, may unite into 
 one; and these again into other compounds, without end. It is 
 hardly necessary to mention, that as two complex ideas unite to 
 form a duplex one, not only two, but more than two may so 
 unite; and what he calls a duplex idea may be compounded of 
 two, three, four, or any number of complex ideas. 
 
 Some of the most familiar objects with which we are ac- 
 quainted furnish instances of these unions of complex and 
 duplex ideas. 
 
 Brick is one complex idea, mortar is another complex idea; 
 these ideas, with ideas of position and quantity, compose my 
 idea of a wall. My idea of a plank is a complex idea, my idea of 
 a rafter is a complex idea, my idea of a nail is a complex idea. 
 
 These, united with the same ideas of position and quantity, 
 compose my duplex idea of a floor. In the same manner my 
 complex idea of glass, and wood, and others, compose my 
 duplex idea of a window; and these duplex ideas, united to- 
 gether, compose my idea of a house, which is made up of vari- 
 ous duplex ideas. How many complex, or duplex ideas, are all 
 united in the idea of furniture? How many more in the idea of 
 merchandise? Now many more in the idea called Every 
 Thing?
 
 ALEXANDER BAIN 
 
 (1818-1903) 
 
 THE SENSES AND THE INTELLECT* 
 
 THE INTELLECT 
 
 WE now proceed to view the Intellect, or the thinking func- 
 tion of the mind. The various faculties known as Memory, 
 Judgment, Abstraction, Reason, Imagination, are modes or 
 varieties of Intellect. Although we can hardly ever exert this 
 portion of our mental system in separation from the other ele- 
 ments of mind Feeling and Volition, yet scientific method 
 requires it to be described apart. 
 
 The primary, or fundamental attributes of Thought, or In- 
 telligence, have been already stated to be, Consciousness of 
 Difference, Consciousness of Agreement, and Reieniiveness. The 
 exposition of the Intellect will consist in tracing out the work- 
 ings of these several attributes; the previous book containing 
 the enumeration of all that we at first have to discriminate, 
 identify, and retain. 
 
 (i.) The first and most fundamental property is the Con- 
 sciousness of Difference, or DISCRIMINATION. To be distinc- 
 tively affected by two or more successive impressions is the 
 most general fact of consciousness. We are never conscious at 
 all without experiencing transition or change. (This has been 
 called the Law of Relativity.) When the mental outburst is 
 characterized mainly by pleasure or pain, we are said to be 
 under a state of feeling. When the prominent circumstance is 
 discrimination of the two distinct modes of the transition, we 
 are occupied intellectually. There are many transitions that 
 give little or no feeling in the sense of pleasure or pain, and that 
 are attended to as transitions, in other words, as Differences. 
 
 * London, 1855; 4th ed., 1894.
 
 484 ALEXANDER BAIN 
 
 In states of enjoyment or suffering, we cannot be strictly devoid 
 of the consciousness of difference; but we abstain from the ex- 
 ercise of the discriminating (and the identifying) function, and 
 follow out the consequences of a state of feeling as such, these 
 being to husband the pleasure and abate the pain, by voluntary 
 actions. 
 
 (2.) The fundamental property of Intellect, named RETEN- 
 TIVENESS, has two aspects, or degrees. 
 
 First. The persistence or continuance of mental impressions, 
 after the withdrawal of the external agent. When the ear is 
 struck by a sonorous wave, we have a sensation of sound, but 
 the mental excitement does not die away because the sound 
 ceases; there is a certain continuing effect, generally much 
 feebler, but varying greatly according to circumstances, and on 
 some occasions quite equal to the effect of the actual sensation. 
 In consequence of this property, our mental excitement, due 
 to external causes, may greatly outlast the causes themselves; 
 we are enabled to go on living a life in ideas, in addition to the 
 life in actualities. 
 
 But this is not all. We have, secondly, the power of recover- 
 ing, or reviving, under the form of ideas, past or extinct sensa- 
 tions and feeling of all kinds, without the originals, and by 
 mental agencies alone. 
 
 After the impression of a sound has ceased entirely, and the 
 mind has been occupied with other things, there is a possibility 
 of recovering from temporary oblivion the idea, or mental 
 effect, without reproducing the actual sound. We remember, 
 or bring back to mind, sights, and sounds, and thoughts, that 
 have not been experienced for months or years. This implies a 
 still higher mode of retentiveness than the previous fact; it 
 supposes that something has been engrained in the mental 
 structure; that an effect has been produced of a kind that suc- 
 ceeding impressions have not been able to blot out. Now, one 
 medium of the restoration to consciousness of a particular past 
 state, is the actual presence of some impression that had often
 
 THE SENSES AND THE INTELLECT 485 
 
 occurred in company with that state. Thus we are reminded of 
 a name as ship, star, tree by seeing the thing; the previous 
 concurrence of name and thing has led to a mental companion- 
 ship between the two. Impressions that have frequently ac- 
 companied one another in the mind grow together, so as to 
 become at last almost inseparable : we cannot have one without 
 a disposition or prompting to renew all the rest. This is the 
 highest form of the Retentive, or plastic, property of the mind. 
 It will be exemplified at length under the title of Association by 
 Contiguity. 
 
 (3.) The remaining property of Intellect is consciousness of 
 AGREEMENT. Besides the consciousness of difference, the mind 
 is also affected by agreement rising out of partial difference. 
 The continuance of the same impression produces no effect, 
 but after experiencing a certain impression and passing away 
 from it to something else, the recurrence of the first causes a 
 certain shock or start, the shock of recognition; which is 
 all the greater according as the circumstances of the present 
 and of the past occurrence are different. Change produces one 
 effect, the effect called discrimination ; Similarity in the midst 
 of change produces a new and distinct effect; and these are the 
 two modes of intellectual stimulation, the two constituents of 
 knowledge. When we see in the child the features of the man, 
 we are struck by agreement in the midst of difference. 
 
 This power of recognition, identification, or discovery of 
 likeness in unlikeness, is another means of bringing to mind 
 past ideas; and is spoken of as the Associating, or Reproductive 
 principle of SIMILARITY. We are as often reminded of things by 
 their resemblance to something present, as by their previous 
 proximity to what is now in the view. Contiguity and Similarity 
 express two great principles or forces of mental reproduction; 
 they are distinct powers of the mind, varying in degree among 
 individuals the one sometimes preponderating, and some- 
 times the other. The first governs Acquisition, the second 
 Invention. 
 
 The commonly recognized intellectual faculties, enumerated 
 by Psychologists with much discrepancy, in so far as they do
 
 4 86 ALEXANDER BAIN 
 
 not involve Feeling and Volition, are resolvable into these 
 three primitive properties of Intellect Discrimination, Re- 
 tention, Similarity. The faculty called Memory is almost 
 exclusively founded in the Retentive power, although some- 
 times aided by Similarity. The processes of Reason and 
 Abstraction involve Similarity chiefly; there being in both the 
 identification of resembling things. What is termed Judgment 
 may consist in Discrimination on the one hand, or in the Sense 
 of Agreement on the other: we determine two or more things 
 either to differ or to agree. It is impossible to find any case of 
 Judging that does not, in the last resort, mean one or other of 
 these two essential activities of the intellect. Lastly, Imagina- 
 tion is a product of all the three fundamentals of our intelli- 
 gence, with the addition of an element of Emotion. 
 
 CHAPTER!. RETENTIVENESS LAW OF 
 CONTIGUITY 
 
 i. THIS principle is the basis of Memory, Habit, and the 
 Acquired Powers in general. Writers on Mental Science have 
 described it under various names. Sir William Hamilton terms 
 it the law of "Redintegration," regarding it as the principle 
 whereby one part of a whole brings up the other parts, as when 
 the first words of a quotation recall the remainder, or one house 
 in a street suggests the succeeding ones. The associating links 
 called Order in Time, Order in Place, and Cause and Effect, 
 are all included under it. We might also name it the law of 
 Association proper, of Adhesion, Mental Adhesiveness, or Ac- 
 quisition. 
 
 The following is a general statement of this mode of mental 
 reproduction. 
 
 Actions, Sensations, and States of Feeling, occurring to- 
 gether or in close succession, tend to grow together, or 
 cohere, in such a way that, when any one of them is after- 
 wards presented to the mind, the others are apt to be 
 brought up in idea.
 
 THE SENSES AND THE INTELLECT 487 
 
 There are various circumstances or conditions that regulate 
 and modify the operation of this principle, so as to render the 
 adhesive growth more or less rapid and secure. These will be 
 best brought out by degrees in the course of the exposition. As 
 a general rule, Repetition is necessary in order to render co- 
 herent in the mind a train or aggregate of images, as, for exam- 
 ple, the successive aspects of a panorama, with a sufficient 
 degree of force to make one suggest the others at an after period. 
 The precise degree of repetition needed depends on a variety of 
 causes, the quality of the individual mind being one. 
 
 4. In regard to the conditions that regulate the pace of our 
 various acquisitions, some are general, others are special to 
 individual kinds. 
 
 The general conditions are these: 
 
 I. A certain amount of Continuance, or Repetition of the 
 matter to be learned, is requisite : and the greater the continu- 
 ance, or the more frequent the repetition, the greater the pro- 
 gress of the learner. Deficiency in the other conditions has to 
 be made up by a protracted iteration. 
 
 II. The Concentration of the mind is an important condi- 
 tion. This means physically that the forces of the nevous sys- 
 tem are strongly engaged upon the particular act, which is pos- 
 sible only by keeping the attention from wandering to other 
 things. It is well known that distraction of mind is a bar to 
 acquirement. 
 
 There are various modes of attaining the desired concentra- 
 tion. It is a voluntary act, prompted by present and by future 
 pleasures and pains. 
 
 The greatest of all motives to concentration is a present 
 enjoyment of the work in hand. Any exercise possessing a 
 special charm detains us by immediate attraction ; everything 
 else is neglected so long as the fascination lasts. This is the 
 inherent power of the will in its immediate and most efficient 
 manifestation a present pleasure furthering a present action. 
 It explains the great influence of what is called the Taste for a 
 special pursuit. The taste or fascination for music, for science, 
 for business, keeps the mind of the learner exclusively bent
 
 488 ALEXANDER BAIN 
 
 upon the subject; and the pace of acquisition is proportionally 
 rapid. 
 
 Next to present enjoyment, is associated, or future, enjoy- 
 ment; as when we devote ourselves to something uninteresting 
 or painful in itself, but calculated to bring future gratification. 
 This is, generally speaking, a less urgent stimulation, as being 
 the influence of pleasure existing only in idea. There may, 
 however, be all degrees of intensity of the motive, according to 
 the strength of the ideal representation of the pleasure to come. 
 It is on this stimulation, that we go through the dry studies 
 necessary to a lucrative profession or a favourite object of 
 pursuit. The young are insufficiently actuated by prospective 
 pleasure, owing to their inferior ideal hold of it; and are there- 
 fore not powerfully moved in this way. 
 
 A third form of concentration is when present pain is made 
 use of to deter and withdraw the mind from causes of distrac- 
 tion, or matters having an intrinsically superior charm. This 
 is the final resort in securing the attention of the volatile 
 learner. It is an inferior motive, on the score of economy, but 
 cannot be dispensed with in early training. By an artificial 
 appliance, the subject is made comparatively the most attractive. 
 So with the use of future pains ; the same allowance being made 
 for the difference in their character, as for pleasures existing 
 only in prospect. 
 
 Mere Excitement, whether as pleasure or as pain, or as 
 neither, is a power of intellectual concentration. An idea that 
 excites us very much persists in the mind, even if painful; and 
 the remembrance of it will be stamped in consequence. This 
 influence will be especially noticed, a few pages hence. 
 
 It is not uncommon, in stating the general conditions of Reten- 
 tiveness, or memory, to specify the vividness or intensity of an 
 impression; thus, we readily remember such effects as an intense 
 odour, a speech uttered with vehemence, a conflagration. This, 
 however, resolves itself into the concentration of mental and nerv- 
 ous force, due to the emotional excitement. Apart from the feel- 
 ings, an idea may be more or less distinct and clear, but is not 
 properly more or less intense. If an inscription is legible with ease,
 
 THE SENSES AND THE INTELLECT 489 
 
 it is everything that the intellect demands; the adventitious aid of 
 glaring characters, as when, at a public illumination, a sentiment is 
 written in gas jets, is a species of excitement, securing an inordinate 
 amount of attention or concentration of mind. 
 
 If we compare an object sharply defined with another whose 
 lineaments are faded and obscure, there is a wide difference in the 
 hold that the two would severally take on the memory; but such 
 impressions differ in kind, and not simply in degree. The names 
 'vivid' and 'intense' are scarcely applicable except by a figure. 
 Without a decisive difference or contrast, the mind is not impressed 
 at all; everything that favours the contrast favours discrimination, 
 and also depth of impression. All this, however, is pre-supposed, 
 as a fact or property of the Discriminating function of intellect; 
 and is not to be repeated as appertaining to the Retentive function. 
 
 III. There appears to be specific to each individual a certain 
 degree of General Retentiveness, or a certain aptitude for 
 acquirement generally. We find a great inequality in the 
 progress of learners placed almost exactly in the same circum- 
 stances. Sometimes the difference refers only to single depart- 
 ments, as mechanical art, music, or language; it is then refer- 
 able to special and local endowments, as muscular sensibility, 
 the musical ear, and so forth. Often, however, the superiority 
 of individuals is seen in acquirement as a whole, in which form 
 it is better regarded as a General power of Retentiveness. 
 
 5. We shall advert, as we proceed, to the modifying circum- 
 stances of a local kind peculiar to each class of acquisitions. 
 As respects the present class, Movements, the special condi- 
 tions seem to be as follows : 
 
 (i.) Bodily Strength, or mere muscular vigour, must be 
 regarded as favouring acquisition. Not only is it an indication 
 of a large share of vitality in the muscles, which is likely to 
 attend their acquired aptitudes; it also qualifies for enduring, 
 without fatigue, a great amount of continuance or practice of 
 the operations required. 
 
 (2.) Distinct from mere muscular power is Spontaneity, or 
 the active temperament; meaning the natural proneness to 
 copious muscular activity. This must be regarded as a pro-
 
 490 ALEXANDER BAIN 
 
 perty, not of the muscular tissue, but of the nerve-centres on 
 the active side of the brain. Hence there is a likelihood, if not a 
 certainty, that the endowment is accompanied with a greater 
 facility in the association of movements. Observation accords 
 with the view. It is usually men of abounding natural activity 
 that make adroit mechanics, good sportsmen, and able com- 
 batants. 
 
 (3.) Of still greater importance is Muscular Delicacy, or 
 Discrimination, which is not necessarily involved in either of 
 the foregoing heads, although more allied to the second. The 
 power of discriminating nice shades of muscular movement is 
 at the foundation of muscular expertness in every mode. We 
 have abundant proof that, wherever delicacy of discrimination 
 exists, there exists also a special retentiveness of that class of 
 impressions. The physical groundwork of the property is the 
 abundance of the nerve elements fibres and corpuscles out 
 of which also must spring the capacity for varied groupings and 
 fixed associations. 
 
 Physical vigour in general, and those modes of it that are the 
 counterparts of mental vigour in particular, must be reckoned 
 among the conditions of Retentiveness. Other things being the 
 same, acquisition is most rapid in health, and in the nourished and 
 fresh condition of all the organs. When the forces of the system run 
 strongly to the nervous system in general, there is a natural exuber- 
 ance of all the mental manifestations; and energy of mind is then 
 compatible with much bodily feebleness, yet not with any circum- 
 stances that restrict the nourishment of the brain. 
 
 CHAPTER II. AGREEMENT LAW OF SIMILARITY 
 
 Present Actions, Sensations, Thoughts, or Emotions 
 tend to revive their LIKE among previous Impres- 
 sions, or States. 
 
 i. CONTIGUITY joins together things that occur together, or 
 that are, by any circumstance, presented to the mind at the 
 same time; as when we associate heat with light, a falling body
 
 THE SENSES AND THE INTELLECT 491 
 
 with a concussion. But, in addition to this link of reproductive 
 connexion, we find that one thing will, by virtue of Similarity, 
 recall another separated from it in time, as when a portrait recalls 
 the original. 
 
 The second fundamental property of Intellect, termed Con- 
 sciousness of Agreement, or Similarity, is a great power of 
 mental reproduction, or a means of recovering past mental 
 states. It was noticed by Aristotle as one of the links in the 
 succession of our thoughts. 
 
 As regards our knowledge, or perception, of things, the conscious- 
 ness of Agreement is second only to Discrimination, or the con- 
 sciousness of Difference. When we know a thing, we do so by its 
 differences and its agreements. Our full knowledge of red, is our 
 having contrasted it with all other colours, and our having compared 
 it with itself and with its various shades. Our knowledge of a chair 
 is made up of our experiences of the distinction between it and other 
 articles of furniture, &c., and of the agreement between it and other 
 chairs. Both modes are involved in a complete act of cognition, and 
 nothing else (except, of course, the Retentiveness implied in the one 
 and the other) is necessary. Our knowledge of man is the sum of the 
 points of contrast between a man and all other things, and the sum 
 of the points of identity on comparing men with one another. Our 
 increase in knowledge is constantly proceeding in both directions: 
 we note new differences, and also new agreements, among our 
 experiences, object and subject. We do not begin to be conscious 
 till we have the shock of difference; and we cannot make that 
 analysis of our conscious states, called the recognition of plurality, 
 combination, or complication, till we discover agreements, and refer 
 each part of the impression to its like among our previous impres- 
 sions. To perceive is, properly, to recognize, or identify. 
 
 2. Some preliminary explanation of the kind of relationship 
 subsisting between the two principles of Contiguity and Simi- 
 larity, is requisite in order to guard against mistakes, and 
 especially to prevent misapprehension, as to the separate exist- 
 ence of the two modes of action in the mental framework. 
 When the cohesive link between any two contiguous actions, 
 or images, is confirmed by a new occurrence or repetition,
 
 492 ALEXANDER BAIN 
 
 obviously the present impression must revive the sum total of 
 the past impressions, or reinstate the whole mental condition 
 left on the occasion immediately preceding. Thus, if I am dis- 
 ciplining myself in the act of drawing a round figure with my 
 hand any one present effort must recall the state of the mus- 
 cular and nervous action, or the precise bent acquired at the end 
 of the previous effort, while that effort had to reinstate the con- 
 dition at the end of the one preceding, and so on. It is only in 
 this way that repetition can be of any avail in confirming a 
 physical habit, or in forming an intellectual aggregate. But 
 this reinstatement of a former condition by a present act of the 
 same kind, is really and truly a case of the operation of the 
 associating principle of similarity, or of like recalling like; and 
 we here plainly see, that without such recall, the adhesion of 
 contiguous things would be impossible. Hence it would appear, 
 that all through the exposition of Contiguity, the principle of 
 Similarity has been tacitly assumed; we have everywhere taken 
 for granted, that a present occurrence of any object to the view 
 recalls the total impression made by all the previous occur- 
 rences, and adds its own effect to that total. 
 
 But, by thus tacitly assuming the power of anything present 
 to reinstate the past impressions of the same thing, we restrict 
 ourselves to those cases where the reinstatement is sure and 
 certain, in fact to cases of absolute identity of the present and 
 past. Such is the nature of the instances dwelt upon in the pre- 
 vious chapter: in all of them, the new movement, or the new 
 image, was supposed precisely identical with the old, and went 
 simply to reinstate and to deepen an impression already made. 
 We must, however, now pass beyond this field of examples, and 
 enter upon a new class where the identity is only partial, and is 
 on that account liable to be missed; where the restoration, 
 instead of being sure, is doubtful; and where, moreover, the 
 reinstatement serves higher purposes than .the mere iteration 
 and deepening of the impression already made. In all mental 
 restorations whatsoever, both Contiguity and Similarity are at 
 work; in one class, the question is as to the sufficiency of the 
 contiguous bond, the similarity being sure; in another class, the
 
 THE SENSES AND THE INTELLECT 493 
 
 question is as to the sufficiency of the attractive force of the 
 likeness, the contiguous adhesiveness being believed certain. 
 If I chance to meet with a person I have formerly seen, and 
 endeavour^ to remember his name, it will depend upon the 
 goodness of a cohesive link whether or not I succeed ; there will 
 be no difficulty in my recalling the past impression of his per- 
 sonal appearance through the force of the present impression; 
 but having recalled the full total of the past impressions, I may 
 not be able to recover the accompaniment of the name; the con- 
 tiguity may be at fault, although the similarity works its per- 
 fect work of restoring to me my previous conception of the per- 
 sonal aspect. If, on the other hand, I see a man on the street, 
 and if I have formerly seen a portrait of that man, it is a ques- 
 tion whether the living reality shall recall the portrait; the 
 doubt hangs not upon the contiguity, or coherence of the parts 
 and surroundings of the picture, if it could be recovered, but 
 upon the chance of its being recovered. Where things are 
 identical, the operation of similarity, in making the present 
 case revive the former ones, is so certain that it is not even 
 mentioned; we talk of the goodness of the cohesive bond be- 
 tween the revived part and its accompaniments, as if contigu- 
 ity expressed the whole fact of the restoration. To make up for 
 this partiality of view, which was indispensable to a clear expo- 
 sition, we now embrace, with the like partial and prominent 
 consideration, the element that was left in a latent condition; 
 and allow to sink, into the latent state, the one that has 
 hitherto been made exclusively prominent. 
 
 3. In the perfect identity between a present and a past 
 impression, the past is recovered and fused with the present, 
 instantaneously and surely. So quick and unfaltering is the 
 process that we lose sight of it altogether; we are scarcely made 
 aware of the existence of an associating link of similarity in the 
 chain of sequence. When I look at the full moon, I am in- 
 stantly impressed with the state arising from all my former 
 impressions of her disc added together; so natural and neces- 
 sary does this restoration seem, that we rarely reflect on the 
 principle implied in it, namely, the power of the new stimulus
 
 494 ALEXANDER BAIN 
 
 to set on the nervous currents, with all the energy acquired in 
 the course of many hundred repetitions of the same visual im- 
 petus. But when we pass from perfect to imperfect or partial 
 identity, we are more readily made aware of the existence of 
 this link of attraction between similars, for we find that some- 
 times the restoration does not take place; cases occur where we 
 fail to be struck with a similitude; the spark does not pass be- 
 tween the new currents and the old dormant ones. The failure 
 in reinstating the old condition by virtue of the present stimu- 
 lus, is, in the main, ascribable to imperfect identity. When, in 
 some new impression of a thing, the original form is muffled, ob- 
 scured, distorted, disguised, or in any way altered, it is a chance 
 whether or not we identify it; the amount of likeness that 
 remains will have a reviving power, or a certain amount of rein- 
 stating energy, but the points of difference or unlikeness will 
 operate to resist the supervention of the old state, and will tend 
 to revive objects like themselves. If I hear a musical air that I 
 have been accustomed to, the new impression revives the old as 
 a matter of course; but if the air is played with complex har- 
 monies and accompaniments, it is possible that the effect of 
 these additions may be to check my recognition of the piece; 
 the unlike circumstances may repel the reinstatement of the 
 old experience more powerfully than the remaining likeness 
 attracts it; and I may find in it no identity whatever with an 
 air previously known, or even identify it with something alto- 
 gether different. If my hold of the essential character of the 
 melody is but feeble, and if I am stunned and confounded with 
 the new accompaniments, there is every likelihood that I shall 
 not experience the restoration of my past hearing of the air 
 intended, and consequently I shall not identify the perform- 
 ance. 
 
 4. The obstructives to the revival of the past through simili- 
 tude, may be classed under the two heads Faintness and 
 Diversity. There are instances where a new impression is too 
 feeble to strike into the old-established track of the same impres- 
 sion, and to make it alive again; as when we are unable to iden- 
 tify the taste of a very weak solution, or to discern an object in
 
 THE SENSES AND THE INTELLECT 495 
 
 twilight dimness. The most numerous and interesting cases 
 come, however, under the other head Diversity, or mingled 
 likeness and unlikeness; as when we meet an old acquaintance 
 in a new dress, or in circumstances where we have never seen 
 the same person before. The modes of diversity are countless, 
 and incapable of being classified. We might, indeed, include 
 under diversity the other of the two heads, seeing that faintness 
 implies diversity of degree, if not of any other circumstance; but 
 I prefer considering the obstruction arising from faintness by 
 itself, after which we shall proceed to the larger field of exam- 
 ples marked by unlikeness in other respects. 
 
 5. The difficulty or facility in resuming a past mental condi- 
 tion, at the suggestion of a present similitude, will plainly de- 
 pend upon the hold that the past impression has acquired ; it is 
 much easier to revive a familiar image than an unfamiliar, by 
 the force of a new presentation. We shall, therefore, have to 
 keep this circumstance in view, among others, in the course of 
 our illustration of the law of Similarity. 
 
 It has to be considered how far natural character that is, 
 a primitive endowment of the intellect, enters into the power 
 of reviving similars, or of bringing together like things in spite 
 of the repulsion of unlike accompaniments. There is much to 
 be explained in the preferences shown by different minds, in the 
 objects that they most readily recall to the present view; which 
 preferences determine varieties of character, such as the scien- 
 tific and the artistic minds. The explanation of these differ- 
 ences was carried up to a certain point under the Law of Con- 
 tiguity; but, if I am not mistaken, there is still a portion 
 referable to the existence of various modes and degrees of sus- 
 ceptibility to the force of Similarity. From all that I have been 
 able to observe, the two energies of contiguous adhesion, and of 
 attraction of similars, do not rise and fall together in the char- 
 acter; we may have one feeble and the other strong, in all pro- 
 portions and degrees of adjustment. I believe, moreover, that 
 there is such a thing as an energetic power of recognizing simi- 
 larity in general, and that this is productive of remarkable con- 
 sequences. Whether I shall be able to impress these convictions
 
 496 ALEXANDER BAIN 
 
 upon my readers, will depend upon the success of the detailed 
 exposition of this noted peculiarity of our intellectual nature. 
 
 CHAPTER III. COMPOUND ASSOCIATION 
 
 i. HITHERTO we have restricted our attention to single 
 threads or indivisible links of association, whether of Contig- 
 uity or Similarity. It remains for us to consider the case where 
 several threads, or a Plurality of links or bonds of connexion, 
 unite in reviving some previous thought or mental state. No 
 new principle is introduced here; we have merely to note, what 
 seems an almost unavoidable effect of the combined action, that 
 the reinstatement is thereby made more easy and certain. As- 
 sociations that are individually too weak, to operate the revival 
 of a past idea, may succeed by acting together; and there is 
 thus opened up to our view a means of aiding our recollection, 
 or invention, when the one thread in hand is too feeble to effect 
 a desired recall. It happens in fact, that, in a very large num- 
 ber of our mental transitions, there is present a multiple bond 
 of association. 
 
 The combinations may be made up of Contiguities alone, 
 of Similarities alone, or of Contiguity and Similarity mixed. 
 Moreover, we shall find that in Emotion and in Volition there 
 are influences either assisting or obstructing the proper intel- 
 lectual forces. In the reviving of a past image or idea, it is 
 never unimportant, that the revival gratifies a favourite emo- 
 tion, or is strongly willed in the pursuit of an end. We must 
 endeavour to appreciate, as far as we are able, the influence of 
 these extra-intellectual energies within the sphere of intellect; 
 but, as they would rarely suffice for the reproduction of thought, 
 if acting apart and alone, we are led to look at them chiefly as 
 modifying the effects of the strictly intellectual forces, or as 
 combining elements in the composition of associations. 
 
 The general law may be stated as follows : 
 
 Past actions, sensations, thoughts, or emotions, are re- 
 called more easily, when associated either through con- 
 tiguity or through similarity, with more than one present 
 object or impression.
 
 THE SENSES AND THE INTELLECT 497 
 
 COMPOSITION OF CONTIGUITIES 
 
 2. We begin with the composition of contiguities. Instances 
 might be cited under all the heads of the first chapter; but a 
 less profuse selection will suffice. There will, however, be a 
 gain in clearness by taking Conjunctions and Successions 
 separately. 
 
 Conjunctions. For a simple example of a compound con- 
 junction, we may suppose a person smelling a liquid and iden- 
 tifying the smell as something felt before, but unable to recall 
 to mind the material causing it. Here the bond between an 
 odour and the odorous substance is too feeble for reproducing 
 the idea or the name of the substance. Suppose farther that 
 the person could taste the liquid without feeling the odour, and 
 that in the taste he could recognize a former taste, but could 
 not remember the thing. If, in these circumstances, the con- 
 currence of the two present sensations of taste and smell 
 brought the substance to the recollection, we should have a 
 true instance of composite association. If one of the two links 
 is fully equal to the restoring effect, there is no case under the 
 present law; in order to constitute a proper example, each 
 should be insufficient when acting singly. Although there can 
 be no doubt as to the fact of such revivals, we might easily sup- 
 pose it otherwise. Combination is not strength under all cir- 
 cumstances. A gallon of water at 40, cannot yield a spoonful 
 at 41. Ten thousand commonplace intellects would not 
 make one genius, under any system of co-operation. The mul- 
 tiplication of unaided eyes could never equal the vision of one 
 person with a telescope, or a microscope. 
 
 We have seen that the complex wholes around us in the world, 
 are held together in the recollection by the adhesive force of 
 Contiguity; such objects as a tree, a human figure, a scene in 
 nature, cannot continue in the mind, or be revived as ideas, 
 until frequent repetition has made all the parts coherent. After 
 the requisite iteration, a complex object, such as a rural village, 
 may be revived by the presence of a single portion of it, as some 
 street, or building, or marked locality. But, if the village is one
 
 498 . ALEXANDER BAIN 
 
 not very well known, that is, if the notion of it is not very firmly 
 aggregated in the mind, the traveller just entering may be not 
 ready to identify it by the first thing that strikes him ; he may 
 require to go on till several other objects come in view, when 
 probably their joint impression will be able to bring up the 
 whole, in other words, will remind him what village he is now 
 entering. 
 
 So in regarding objects as concretes, or combinations of many 
 distinct qualities, an orange, for example, which affects all 
 the senses, a fixing process makes the different sensations 
 hold together in one complex idea. Here, too, there is room for 
 the joint action of associating links in recalling an image to the 
 mind. I have already imagined a case of this description, where 
 the united action of smell and of taste was supposed to revive 
 the idea of the concrete object causing them, either being of 
 itself insufficient for the purpose. 
 
 5. Successions. I have dwelt at length, in a previous chap- 
 ter, on the contiguous association of successions of various 
 kinds. Here, too, in the circumstance of imperfect adhesion, 
 the recovery may be due to a composite action. I have wit- 
 nessed a series of events, and these are, in consequence, associ- 
 ated in my mind. In endeavouring to recall the series from the 
 commencement, a link fails, until some other association, such 
 as place, or person, contributes an assisting thread. 
 
 There is one succession that contains the whole of our experi- 
 ence, that is, the Order of Time, or the sequence of events in 
 each one's own history. If all the minutiae of this succession 
 were to cohere perfectly in the mind, everything that we have 
 ever done, seen, or been cognizant of, could be recovered by 
 means of it. But although all the larger transactions, and the 
 more impressive scenes, of our personal history, are linked in 
 this order with a sufficient firmness, yet for smaller incidents 
 the bond is too weak. I cannot remember fully my yesterday's 
 train of thoughts; nor repeat verbatim an address of five 
 minutes' length, whether spoken or heard. Things related in 
 the order of time are, strictly speaking, experienced only once, 
 and we usually require repetition to fix any mental train. It
 
 THE SENSES AND THE INTELLECT 499 
 
 constantly happens, therefore, that we are in search of some 
 reinforcing connexion to help us in recovering the stream of 
 events, as they occurred in the order of time. We seek for other 
 conjunctions and successions to enable us to recommence after 
 every break. 
 
 Experience teaches us, that the only way of making up a 
 defective adhesion is to compass in our minds some other con- 
 nexion, or to get at the missing object through a new door. The 
 inability to recollect the next occurring particular of a train 
 that we are in want of, stimulates a great effort of volition, and 
 the true course for the mind to take is to get upon some chain 
 or current that is likely to cross the line of the first near the 
 break. 
 
 At every moment of life, each person stands immersed in a 
 complicated scene, and each object of this scene may become 
 a starting point for a train of recollections. All the internal 
 feelings of the body; everything that surrounds us and strikes 
 the eye, ear, touch, taste, or smell ; all the ideas, emotions, and 
 purposes occupying the mind; these form so many begin- 
 nings of trains of association passing far away into the remot- 
 est regions of recollection and thought; and we have it in our 
 power to stop and change the direction as often as we please. 
 From some one of these present things, we must commence our 
 outgoings towards the absent and the distant, whether treading 
 in single routes, or introducing composite action. 
 
 6. Language. The recall of names by things, and of things 
 by names, gives special occasion for bringing in additional links 
 to aid a feeble tie. When we have forgotten the name of a per- 
 son, or of an object, we are under the necessity of referring back 
 to the situation and circumstances where we have heard the 
 name, to see if any other bond of connexion will spring up. 
 Often we are unable, at the moment, to recover the lost sound 
 by any means; but, afterwards, an auxiliary circumstance 
 crosses the view, and the revival is effected. 
 
 Many of our recollections, thoughts, conceptions, and imag- 
 inings, are an inextricable mixture of language and ideas of 
 things. The notions that we acquire through oral instruction,
 
 Soo ALEXANDER BAIN 
 
 or from books, are made up in part by the subject matter 
 purely, and in part by the phraseology that conveyed it. Thus, 
 my recollection of a portion of history is made up of the train of 
 words, with the train of historical facts and scenes, as I might 
 have seen them with my own eyes. So in many sciences, there 
 is a combination of visual or tactual notions with language. 
 Geometry is a compound of visible diagrams with the language 
 of definitions, axioms, and demonstrations. Now, in all these 
 cases, recollection may depend, either on the associations of 
 words, or on those of visual and other conceptions, or on a com- 
 pound of both. If I listen to a geographical description, there 
 is, in the first place, a train of words dropping on my ear; and, 
 by virtue of a perfect verbal cohesion, I might recall the whole 
 description and recite it to another party. In the second place, 
 there is a series of views of objects of mountain, river, plain, 
 and forest which I picture in my mind and retain inde- 
 pendently of the language used to suggest them. Were my pic- 
 torial adhesion strong enough, I could recall the whole of the 
 features in the order that I was made to conceive them, and 
 leave aside the language. The common case, however, is that 
 the recollection is effected by a union of both the threads of 
 cohesion ; the pictorial train is assisted by the verbal, and the 
 verbal by the pictorial, as may happen. 
 
 COMPOSITION OF SIMILARITIES 
 
 7. The influence of the multiplication of points of likeness, 
 in securing the revival of a past object, is liable to no uncer- 
 tainty. It is only an extension of the principle maintained all 
 through the discussion of the law of similarity, that the greater 
 the similitude, and the more numerous the points of resem- 
 blance, the surer is the stroke of recall. If I meet a person very 
 like some one else I have formerly known, the probability of 
 my recalling this last person to view is increased, if the likeness 
 in face and feature is combined with similarity of dress, of 
 speech, of gait, or of any still more extraneous points, such as 
 occupation, or history. Increase of resemblance extensively,
 
 THE SENSES AND THE INTELLECT 501 
 
 that is by outward connexions, has the same power as increase 
 of resemblance intensively, in rendering the restoration of the 
 past more certain. It might admit of a doubt whether four faint 
 links of contiguous adhesion would be equal to one strong link, 
 but it would be against our whole experience of the workings 
 of similarity, to doubt the utility of multiplying faint resem- 
 blances, when there was no one sufficiently powerful to effect 
 the revival. At the same time, we must admit that much more 
 is contributed to the chances of reinstatement by intensifying 
 one point of likeness, than by adding new ones of a faint char- 
 acter. By raising some single feature almost up to the point of 
 identity, we should do more good than could be done by scat- 
 tering faint and detached likenesses over the picture. This, 
 however, is not always in our power; and we are glad to find, 
 that, when the similarity, in any one particular, is too feeble 
 to suggest the resembling past, the existence of a plurality of 
 weak resemblances will be the equivalent of a single stronger 
 one. 
 
 On this view, I might set forth the workings of composite 
 similarities, from the various classes of examples gone over in 
 the preceding chapter. In all very complicated conjunctions, 
 as, for example, a landscape, there may be a multiplication of 
 likenesses, unable to strike singly, but, by their concurrence 
 suggesting a parallel scene. Hence, in endeavouring to recall 
 resembling things, we may proceed, as in Contiguity, by hunt- 
 ing out new collaterals, on the chance of increasing the amount 
 of similitude, and, with that, the attractive power of the pres- 
 ent for the absent. If I am endeavouring to recall to mind 
 some historic parallel to a present political situation, suppos- 
 ing one to exist and to have been at some former time impressed 
 on my mind, there may be a want of any single salient like- 
 ness, such as we admit to be the most effective medium of 
 reinstatement; and I must, therefore, go over in my mind all 
 the minute features of the present, to enhance, in this way, 
 the force of the attraction of similitude for the forgotten 
 parallel. 
 
 8. The case noticed at the conclusion of the preceding head,
 
 S 02 ALEXANDER BAIN 
 
 namely, the combination of language with subject-matter in a 
 mixed recollection, is favourable to the occurrence of com- 
 pound similarity. If an orator has to deal with a special point, 
 the conduct of an individual, for example, which he wishes to 
 denounce by a cutting simile, his invention may be aided by 
 some similarity in the phrases descriptive of the case, as well as 
 in the features of the case itself. If one who has at a former time 
 read the play of (Edipus, now commences to read Lear, the 
 similarity is not at first apparent, but long before the conclu- 
 sion there will be a sufficient accumulation of features of simili- 
 tude, in dramatic situation and in language, to bring CEdipus to 
 mind without any very powerful stretch of intellectual force. 
 So, in scientific invention; a fact described in language has a 
 double power of suggestion; and if, by good luck, the fact has a 
 likeness to some other fact, and the description resembles the 
 language that accompanied that other when formerly present 
 to the mind, there is so much the more chance of the revival 
 taking place. 
 
 MIXED CONTIGUITY AND SIMILARITY 
 
 9. Under this head, there are several interesting examples. 
 
 If any one, in describing a storm, employ the phrase ' a war 
 of elements,' the metaphor has been brought to mind partly by 
 similitude, but partly also by contiguity, seeing that the com- 
 parison has already been made. The person that first used the 
 phrase came upon it by similarity; he that used it next had con- 
 tiguity to assist him; and, after frequent repetition, the bond 
 of contiguity may be so well confirmed, that the force of 
 similarity is. entirely superseded. In this way, many things 
 that were originally strokes of genius, end in being efforts of 
 mere adhesive recollection; while, for a time previous to this 
 final consummation, there is a mixed effort of the two suggest- 
 ing forces. Hence Johnson's remark on the poet Ogilvie, that 
 his poem contained what was once imagination, but in him had 
 come to be memory. 
 
 In all regions of intellectual exertion industry, science,
 
 THE SENSES AND THE INTELLECT 503 
 
 art, literature there is a kind of ability displayed in taking 
 up great and original ideas and combinations, before they have 
 been made easy by iteration. Minds unable for the highest 
 efforts of origination may yet be equal to this second degree of 
 genius, wherein a considerable force of similarity is assisted by 
 a small thread of contiguity. To master a large multitude of 
 the discoveries of identification, a power of similarity short of 
 the original force that gave birth to them, is aided by the con- 
 tiguous bond that has grown up, during a certain number of 
 repetitions of each. 
 
 10. A second case is, when a similarity is struck out in cir- 
 cumstances such as to bring the absent object into near proxim- 
 ity in some contiguous train. Thus, a poet falls upon a beautiful 
 metaphor, while dwelling in the region where the material of the 
 simile occurs. In the country, rural comparisons are most 
 easily made; on ship-board, nautical metaphors are naturally 
 abundant. 
 
 If we chance to be studying by turns two different sciences 
 that throw much light on each other, we are in the best position 
 for deriving the benefit of the comparison. When we know the 
 most likely source of fertile similitudes for some difficult prob- 
 lem, we naturally keep near that source, in order that we may 
 be struck with the faintest gleam of likeness, through the help 
 of proximity. A historian of the ancient republics cultivates a 
 familiarity with all the living instances of the republican sys- 
 tem. Now that physical science is largely indebted to mathe- 
 matical handling, the physicist has to maintain his freshness in 
 mathematics. It is not safe to trust to an acquisition of old 
 date, however pertinacious the mind be in retaining the subject 
 in question-. The great discoveries of identification that aston- 
 ish the world and open up new vistas of knowledge, have doubt- 
 less often been helped by the accidental proximity of the things 
 made to flash together. For illustration's sake, we might sup- 
 pose Newton in the act of meditating upon the planetary at- 
 traction, at the time that the celebrated apple fell to the ground 
 before his eyes; a proximity so very close would powerfully aid 
 in bringing on the stroke of identification.
 
 504 ALEXANDER BAIN 
 
 CHAPTER IV. CONSTRUCTIVE ASSOCIATION 
 
 By means of Association, the mind has the power to form 
 new combinations, or aggregates, different from any that 
 have been presented to it in the course of experience. 
 
 i. THROUGHOUT the whole of the preceding exposition, we 
 have had in view the literal resuscitation, revival, or reinstate- 
 ment of former actions, images, emotions, and trains of thought. 
 No special reference has been made to the operations known by 
 such names as Imagination, Creation, Constructiveness, Orig- 
 ination; through which we are supposed to put together new 
 forms, or to construct images, conceptions, pictures, and 
 modes of working, such as we have never before had any expe- 
 rience of. Yet the genius of the Painter, the Poet, the Musi- 
 cian, and the Inventor in the arts and sciences, evidently im- 
 plies a process of this nature. 
 
 Under the head of Similarity, we have had to recognize a 
 power tending to originality and invention, as when in virtue 
 of the identifying of two things lying far apart in nature 
 whatever is known of the one is instantly transferred to the 
 other, thereby constituting a new and instructive combination 
 of ideas. Such was the case when Franklin's identification of 
 electricity and thunder, led to the application of the Leyden jar 
 to explain a thunderstorm. The power of recalling like by like, 
 in spite of remoteness, disguise, and false lures, enters into 
 a very large number of inventive efforts, both in the sciences and 
 in the arts. But we have now to deal with constructions of a 
 higher order of complexity. There are discoveries that seem 
 nothing short of absolute creations, as the whole science of 
 Mathematics; while, in the Fine Arts, a frieze of the Parthe- 
 non, a Gothic cathedral, a Paradise Lost, are very far beyond 
 the highest stretches of the identifying faculty taken by itself. 
 
 Nevertheless, the intellectual forces operating in those crea- 
 tions, are no other than the associating forces already discussed. 
 The new combinations grow out of elements already possessed 
 by the mind, and brought to view according to the laws above 
 laid down.
 
 HERBERT SPENCER 
 
 (1820-1903) 
 
 THE PRINCIPLES OF PSYCHOLOGY* 
 
 PART II. THE INDUCTIONS OF PSYCHOLOGY 
 CHAPTER II. THE COMPOSITION OF MIND 
 
 64. IN the last chapter we incidentally encroached on 
 the topic to which this chapter is to be devoted. Certain 
 apparently-simple feelings were shown to be compounded of 
 units of feeling; whence it was inferred that possibly, if not 
 probably, feelings of other classes are similarly compounded. 
 And 'n thus treating of the composition of feelings, we, by 
 implication, treated of the composition of Mind, of which feel- 
 ings are themselves components. 
 
 Here, however, leaving speculations about the ultimate 
 composition of Mind, we pass to observations on its proximate 
 composition. Accepting as really simple those constituents of 
 Mind which are not decomposable by introspection, we have 
 to consider what are their fundamental distinctive characters, 
 and what are the essential principles of arrangement among 
 them. 
 
 65. The proximate components of Mind are of two broadly- 
 contrasted kinds Feelings and the Relations between feel- 
 ings. Among the members of each group there exist multitud- 
 inous unlikenesses, many of which are extremely strong; but 
 such unlikenesses are small compared with those which dis- 
 tinguish members of the one group from members of the other. 
 Let us, in the first place, consider what are the characters which 
 all Feelings have in common, and what are the characters which 
 Relations between feelings have in common. 
 
 * London, 1855; 2d ed. ib. 1870; 3d ed. ib. 1881; 5th ed. 1890.
 
 5o6 HERBERT SPENCER 
 
 Each feeling, as we here define it, is any portion of conscious- 
 ness which occupies a place sufficiently large to give it a per- 
 ceivable Individuality; which has its individuality marked off 
 from adjacent portions of consciousness by qualitative con- 
 trasts; and which, when introspectively contemplated, appears 
 to be homogeneous. These are the essentials. Obviously if 
 under introspection, a state of consciousness is decomposable, 
 into unlike parts that exist either simultaneously or succes- 
 sively, it is not one feeling but two or more. Obviously if it is 
 indistinguishable from an adjacent portion of consciousness, it 
 forms one with that portion is not an individual feeling but 
 part of one. And obviously if it does not occupy in conscious- 
 ness an appreciable area, or an appreciable duration, it cannot 
 be known as a feeling. 
 
 A relation between feelings is, on the contrary, characterized 
 by occupying no appreciable part of consciousness. Take away 
 the terms it unites, and it disappears along with them ; having 
 no independent place no individuality of its own. It is true, 
 that, under an ultimate analysis, what we call a relation proves 
 to be itself a kind of feeling the momentary feeling accom- 
 panying the transition from one conspicuous feeling to an 
 adjacent conspicuous feeling. And it is true that, notwith- 
 standing its extreme brevity, its qualitative character is appre- 
 ciable; for relations are (as we shall hereafter see) distinguish- 
 able from one another only by the unlikenesses of the feelings 
 which accompany the momentary transitions. Each relational 
 feeling may, in fact, be regarded as one of those nervous shocks 
 which we suspect to be the units of composition of feelings; and, 
 though instantaneous, it is known as of greater or less strength 
 and as taking place with greater or less facility. But the con- 
 trast between these relational feelings and what we ordinarily 
 call feelings, is so strong that we must class them apart. Their 
 extreme brevity, their small variety, and their dependence on 
 the terms they unite, differentiate them in an unmistakeable 
 way. 1 
 
 1 It will perhaps be objected that some relations, as those between things 
 which are distant in Space or in Time, occupy distinguishable portions of con-
 
 THE PRINCIPLES OF PSYCHOLOGY 507 
 
 Perhaps it will be well to recognize more fully the truth that 
 this distinction cannot be absolute. Besides admitting that, as 
 an element of consciousness, a relation is a momentary feeling, 
 we must also admit that just as a relation can have no existence 
 apart from the feelings which form its terms, so a feeling can 
 exist only by relations to other feelings which limit it in space 
 or time or both. Strictly speaking, neither a feeling nor a rela- 
 tion is an independent element of consciousness: there is 
 throughout a dependence such that the appreciable areas of 
 consciousness occupied by feelings, can no more possess indir 
 vidualities apart from the relations which link them, than these 
 relations can possess individualities apart from the feelings they 
 link. The essential distinction between the two, then, appears 
 to be that whereas a relational feeling is a portion of conscious- 
 ness inseparable into parts, a feeling ordinarily so-called, is a 
 portion of consciousness that admits imaginary division into 
 like parts which are related to one another in sequence or co- 
 existence. A feeling proper is either made up of like parts that 
 occupy time, or it is made up of like parts that occupy space, or 
 both. In any case, a feeling proper is an aggregate of related 
 like parts, while a relational feeling is undecomposable. And 
 this is exactly the contrast between the two which must result 
 if, as we have inferred, feelings are composed of units of feeling, 
 or shocks. 
 
 66. Simple feelings as above defined, are of various kinds. 
 To say anything here about the classification of them, involves 
 some forestalling of a future chapter. This breach of order, 
 however, is unavoidable; for until certain provisional groupings 
 have been made, further exposition is scarcely practicable. 
 
 Limiting our attention to seemingly-homogeneous feelings 
 as primarily experienced, they may be divided into the feelings 
 which are centrally initiated and the feelings which are peri- 
 
 sciousness. These, however, are not the simple relations between adjacent 
 feelings which we are here dealing with. They are relations that bridge over 
 great numbers of intervening feelings and relations; and come into existence 
 only by quick transitions through these intervening states, ending in the consoli- 
 dation of them.
 
 508 HERBERT SPENCER 
 
 pherally initiated emotions and sensations. These have 
 widely unlike characters. Towards the close of this volume 
 evidence will be found that while the sensations are relatively 
 simple, the emotions, though seeming to be simple are ex- 
 tremely compound; and that a marked contrast of character 
 between them hence results. But without referring to any 
 essential unlikeness of composition, we shall shortly see that 
 between the centrally-initiated feelings and the peripherally- 
 initiated feelings, fundamental distinctions may be established 
 by introspective comparison. 
 
 A subdivision has to be made. The peripherally-initiated 
 feelings, or sensations, may be grouped into those which, 
 caused by disturbances at the ends of nerves distributed on 
 the outer surface, are taken to imply outer agencies, and those 
 which, caused by disturbances at the ends of nerves distributed 
 within the body, are not taken to imply outer agencies; which 
 last, though not peripherally initiated in the ordinary sense, are 
 so in the physiological sense. But as between the exterior of the 
 body and its interior, there are all gradations of depth, it results 
 that this distinction is a broadly marked one, rather than a 
 sharply marked one. We shall, however, find that certain dif- 
 ferential characters among the sensations accompany this dif- 
 ference of distribution of the nerves in which they arise; and 
 that they are decided in proportion to the relative superficiality 
 or centrality of these nerves. 
 
 In contrast with this class of primary or real feelings, thus 
 divided and subdivided, has to be set the complementary class 
 of secondary or ideal feelings, similarly divided and subdivided. 
 Speaking generally, the two classes differ greatly in intensity. 
 While the primary or originally-produced feelings are relatively 
 vivid, the secondary or reproduced feelings are relatively faint. 
 It should be added that the vivid feelings are taken to imply 
 objective exciting agents then and there acting on the peri- 
 phery of the nervous system; while the faint feelings, though 
 taken to imply objective exciting agents which thus acted at a 
 past time, are not taken to imply their present action. 
 
 We are thus obliged to carry with us a classification based
 
 THE PRINCIPLES OF PSYCHOLOGY 509 
 
 on structure and a classification based on function. The divi- 
 sion into centrally-initiated feelings, called emotions, and peri- 
 pherally-initiated feelings, called sensations; and the subdivi- 
 sion of these last into sensations that arise on the exterior of the 
 body and sensations that arise in its interior; respectively refer 
 to differences among the parts in action. Whereas the division 
 into vivid or real feelings and faint or ideal feelings, cutting 
 across the other divisions at right angles as we may say, refers 
 to difference of amount in the actions of these parts. The first 
 classification has in view unlikenesses of kind among the feel- 
 ings; and the second, a marked unlikeness of degree, common to 
 all the kinds. 
 
 67. From the classes of simple feelings we pass to the 
 classes of simple relations between feelings, respecting which 
 also, something must be said before we can proceed. In default 
 of an ultimate analysis, which cannot be made at present, cer- 
 tain brief general statements must suffice. 
 
 As already said, the requisite to the existence of a relation 
 is the existence of two feelings between which it is the link. The 
 requisite to the existence of two feelings is some difference. 
 And therefore the requisite to the existence of a relation is the 
 occurrence of a change the passage from one apparently- 
 uniform state to another apparently-uniform state, implying 
 the momentary shock produced by the commencement of a 
 new state. 
 
 It follows that the degree of the change or shock, constituting 
 in other words the consciousness of the degree of difference 
 between the adjacent states, is the ultimate basis of the dis- 
 tinctions among relations. Hence the fundamental division of 
 them into relations between feelings that are equal, or those of 
 likeness (which however must be divided by some portion of 
 consciousness that is unlike them), and relations between feel- 
 ings that are unequal, or those of unlikeness. These last fall 
 into what we may distinguish as relations of descending inten- 
 sity and relations of ascending intensity, according as the tran- 
 sition is to a greater or to a less amount of feeling. And they
 
 HERBERT SPENCER 
 
 are further distinguishable into relations of quantitative un- 
 likeness, or those occurring between feelings of the same nature 
 but different in degree, and relations of qualitative unlikeness, 
 or those occurring between feelings not of the same nature. 
 
 Relations thus contemplated simply as changes, and grouped 
 according to the degree of change or the kind of change, sever- 
 ally belong to one or other of two great categories which take 
 no account of the terms as like or unlike in nature or amount, 
 but which take account only of their order of occurrence, as 
 either simultaneous or successive. This fundamental division 
 of relations into those of co-existence and those of sequence, is, 
 however, itself dependent on the preceding division into rela- 
 tions of equality between feelings and relations of inequality 
 between them. For relations themselves have to be classed as of 
 like or unlike kinds by comparing the momentary feelings that 
 attend the establishment of them, and observing whether these 
 are like or unlike, and, as we shall hereafter see, the relations of 
 co-existence and sequence are distinguished from one another 
 only by process of this kind. . 
 
 68. Having defined simple feelings and simple relations, 
 and having provisionally classified the leading kinds of each, 
 we may now go on to observe how Mind is made up of these 
 elements, and how different portions of it are characterized by 
 different modes of combination of them. 
 
 Tracts of consciousness formed of feelings that are centrally* 
 initiated, are widely unlike tracts of consciousness formed of 
 feelings that are peripherally initiated ; and of the tracts of con- 
 sciousness formed of peripherally-initiated feelings, those parts 
 occupied by feelings that take their rise in the interior of the 
 body are widely unlike those parts occupied by feelings that 
 take their rise on the exterior of the body. The marked unlike- 
 nesses are in both cases due to the greater or smaller porpor- 
 tions of the relational elements that are present. Whereas 
 among centrally-initiated feelings, the mutual limitations, both 
 simultaneous and successive, are vague and far between; and 
 whereas among peripherally-initiated feelings caused by inter-
 
 THE PRINCIPLES OF PSYCHOLOGY 511 
 
 nal disturbances, some are extremely indefinite, and few or none 
 definite in a high degree; feelings caused by external disturb- 
 ances are mostly related quite clearly, alike by co-existence and 
 sequence, and among the highest of them the mutual limita- 
 tions in space or time or both, are extremely sharp. These 
 broad contrasts, dependent on the extent to which the elements 
 of feeling are compounded with the elements of relation, cannot 
 be understood, and their importance perceived, without illus- 
 trations. We will begin with those parts of Mind distinguished 
 by predominance of the relational elements. 
 
 Remembering that the lenses of the eye form a nonsentient 
 optical apparatus that casts images on the retina, we may fairly 
 say that the retina is brought more directly into contact with 
 the external agent acting on it than is any other peripheral 
 expansion of the nervous system. And it is in the tracts of con- 
 sciousness produced by the various lights reflected from objects 
 around and concentrated on the retina, that we find the ele- 
 ments of feeling most intimately woven up with the elements of 
 relation. The multitudinous states of consciousness yielded by 
 vision, are above all others sharp in theirmutual limitations; the 
 differences that occur between adjacent ones are extremely 
 definite. It is further to be noted that the relational element is 
 here dominant under both of its fundamental forms. Some of 
 the feelings simultaneously limit one another with great dis- 
 tinctness, and some of them with equal distinctness succes- 
 sively limit one another. The feelings caused by 
 actions on the general surface of the body are marked off clearly, 
 though by no means so clearly as those which arise in the retina. 
 Sensations of touch initiated at points on the skin very near one 
 another, form parts of consciousness that are separate though 
 adjacent; and these are distinguishable not only as co-existing 
 in close promixity, but also as distinct from kindred sensations 
 immediately preceding or immediately succeeding them. 
 Moreover the definiteness of their mutual limitations, in space 
 if not in time, is greatest among the sensations of touch pro- 
 ceeding from parts of the surface which have, in a sense, the 
 greatest externality the parts which, like the tips of the
 
 512 HERBERT SPENCER 
 
 fingers and the tip of the tongue, have the most frequent and 
 varied converse with outer objects. 1 Next in the 
 
 definiteness of their mutual limitations come the auditory feel- 
 ings. Among such of these as occur together, the relations are 
 marked with imperfect clearness. Received through unculti- 
 vated ears, only a few simultaneous sounds are vaguely sepa- 
 rable in consciousness; though received through the ears of a 
 musician, many such sounds may be distinguished and identi- 
 fied. But among successive sounds the relational components 
 of mind are conspicuous. Differences between tones that follow 
 one another, even very rapidly, are clearly perceived. But the 
 demarcations are less decided than those between contrasted 
 sensations in the field of vision. Passing to the sen- 
 
 sations of taste, we see that these, less external in their origin 
 (for it is not in the tip of the tongue, but over its hinder part 
 and the back of the palate, that the gustatory nerves are dis- 
 tributed), are comparatively indefinite in their relations. Such 
 distinctions as may be perceived between tastes that co-exist 
 are comparatively vague, and can be extended to but two or 
 three. Similarly, the beginnings and ends of successive tastes 
 are far less sharp than the beginnings and ends of the visual 
 impressions we receive at every glance; nor can successive 
 tastes be distinguished with anything like the same rapidity as 
 successive tones. Even more undecided are the mu- 
 
 tual limitations among sensations of smell, which, like the last, 
 originate at a considerable distance from the surface (for the 
 nose is not the seat of smell : the olfactory chamber, with which 
 the nostrils communicate, is seated high up between the eyes). 
 Of simultaneous smells the discrimination is very vague; and 
 probably not more than three can be separately identified. Of 
 smells that follow one another, it is manifest that they begin 
 and end indefinitely, and that they cannot be experienced in 
 rapid succession. 
 
 1 The tongue is a much more active tactual organ than at first appears. The 
 mechanical impressions it receives are not limited to those given by the food 
 which it manages during mastication; but at other times it is perpetually explor- 
 ing the inner surfaces of the teeth, which are to it external bodies.
 
 THE PRINCIPLES OF PSYCHOLOGY 513 
 
 We come now to the peripherally-initiated feelings set up by 
 internal disturbances. Among these the most superficial in 
 origin and most relational as they exist in consciousness, are the 
 sensations of muscular tension. Though, except when making 
 vigorous efforts, these are but feeble; though such as are present 
 together mutually limit one another in a very vague way; and 
 though their beginnings and ends are so blurred that a series of 
 them is but indistinctly separable into parts ; yet they are juxta- 
 posed and contrasted to the extent implied by discriminations 
 and recognitions of them discriminations and recognitions so 
 partial, however, as frequently to require indirect verifications. 
 It should be added that the relations among muscular feelings 
 are variable in abundance and distinctness. They are most con- 
 spicuous when the feelings come from muscles that are small, 
 and in perpetual action, as those which move the eyes, the fin- 
 gers, and the vocal organs; and least conspicuous when the 
 feelings come from muscles that are large or centrally seated, 
 or both, as those of the legs and of the trunk. Pass- 
 
 ing over abnormal feelings of pain and discomfort due to dis- 
 turbances of nerves distributed within the limbs and body, 
 among which the small proportion of the relational element is 
 manifest, it will suffice if we come at once to the feelings origin- 
 ating in parts that are remotest from the external world, and 
 which, at least relational, are most distinguished from those we 
 set out with. Hunger is extremely vague in its beginning and 
 end. Commencing unobtrusively and ceasing gradually, it is 
 utterly unlike those feelings which, closely contiguous in time, 
 make one another distinct by mutual limitation. Neither is it 
 appreciably marked out by co-existing feelings; its position 
 among simultaneous states of consciousness is indeterminate. 
 And this indefiniteness of relation, both in space and time, 
 characterizes other visceral feelings, both normal and ab- 
 normal. 
 
 Of the centrally-initiated feelings, or emotions, much the 
 same has to be said as of the last. Their beginnings and endings 
 in time are comparatively indefinite, and they have no definite 
 localizations in space. That is to say, they are not limited by
 
 HERBERT SPENCER 
 
 preceding and succeeding states of consciousness with any pre- 
 cision; and no identifiable bounds are put to them by states of 
 consciousness that co-exist. Here, then, the relational element 
 of mind is extremely inconspicuous. The sequences among 
 emotions that can occur in a given period, are comparatively 
 few and indeterminate; and between such two or three emo- 
 tions as can co-exist it is impossible to distinguish in more than 
 a vague way. 
 
 69. Further and equally important distinctions obtain 
 between the tracts of consciousness thus broadly contrasted, 
 and they are similarly caused. Presence of the relational ele- 
 ments, seen in the mutual limitations of feelings, simultaneous 
 and successive, is accompanied by the mutual cohesion of 
 feelings; and absence of the relational elements, seen in the 
 indeterminate boundaries of feelings in space and time, is 
 accompanied by their incoherence. Let us re-observe the tracts 
 of consciousness above compared. 
 
 The sharply-defined patches of colour that occur together 
 in a visual impression, are indissolubly united held rigidly 
 in juxtaposition. And successive visual feelings, such as are 
 produced by transferring the gaze from one object to another, 
 have a strength of connection that gives a fixed consciousness 
 of their order. Thus the visual feelings, above all others dis- 
 tinguished by the sharpness of their mutual limitations, are 
 absolutely coherent in space and very coherent in time. 
 Between sensations of touch given by an object grasped, the 
 cohesion is not so great. Though the two feelings produced by 
 two points felt simultaneously by a finger, hold together so 
 that they cannot be removed far from one another in con- 
 sciousness; yet the bond uniting them has much less rigidity 
 than the bond uniting the visual feelings produced by the 
 two points; and when the feelings are more than two, their 
 connections in consciousness are loose enough to permit of 
 much variation in the conception of their relative positions. 
 Still the strength of links between co-existing feelings of touch 
 is considerable; as is also that between successive feelings of the
 
 THE PRINCIPLES OF PSYCHOLOGY 515 
 
 same kind. Among the simultaneous feelings caused 
 
 by simultaneous sounds, especially if they are not in harmony, 
 the defect of cohesion is as marked as the defect of mutual 
 limitation. But among the successive feelings produced by suc- 
 cessive sounds, we find that along with distinct mutual limita- 
 tions there go decided mutual cohesions. Sequent notes, or 
 articulations, cling together with tenacity. Much 
 
 less clearly bounded by one another as are tastes, simultaneous 
 and successive, they are also comparatively incoherent. Among 
 co-existent tastes there are no connections like those between 
 co-existent visual feelings, or even like those between the 
 sounds produced at the same instant by a band ; and tastes do 
 not hold together in sequence as do the tones of cadence. 
 Of smells the like is true. Along with vagueness in the bound- 
 ing of one by another there goes but a feeble linking together. 
 The feelings accompanying muscular actions have cohesions 
 that are hidden in much the same way as are their limitations. 
 The difficulty of observing the mutual limitations of muscular 
 feelings, is due to the fact that each muscle, or set of muscles, 
 passes from a state of rest to a state of action or from a state of 
 action to a state of rest, through gradations that occupy an ap- 
 preciable time ; and that, consequently, the accompanying feel- 
 ing, instead of beginning and ending strongly, shades off at both 
 extremes. Being thus weak at the places where they are con- 
 tiguous, these feelings are incapable of strong cohesions. Indeed, 
 if we except those which accompany great efforts, we may say 
 that they are altogether so faint compared with most others 
 that their relations, both in kind and order, are necessarily 
 inconspicuous. Their cohesions are in a great degree those of 
 automatic nervous acts; and are by so much the less the cohe- 
 sions of conscious states. Those very vague feelings 
 which have their seats in the viscera, may, as before, be exem- 
 plified by hunger. Here where we reach such extreme inde- 
 finiteness of limitation, both in space and time, we reach an 
 extreme want of cohesion. Hunger does not suddenly follow 
 some other into consciousness; nor is it suddenly followed by 
 some other. Neither is there any simultaneous feeling to which
 
 516 HERBERT SPENCER 
 
 it clings. The relational element of Mind is almost absent; 
 holding only in a feeble degree with some tastes and smells. 
 
 Lastly^ among the centrally-initiated feelings, or emotions, 
 the same connection of characters occurs. When emotions 
 co-exist, they can scarcely be said to hold together: the bond 
 between them is so feeble, that each may disappear without 
 affecting the others. Between sequent emotions the links have 
 no appreciable strength : no one is attached to another in such 
 way as to produce constancy of succession. And though be- 
 tween emotions and certain more definite feelings which pre- 
 cede them, there are strong connections, yet these connections 
 are not between emotions and single antecedent feelings, but 
 between emotions and large groups of antecedent feelings; and 
 even this cohesion, very variable in its strength, may entirely 
 fail. 
 
 70. A further trait in the composition of Mind, dependent 
 on these correlated traits, may next be set down. We have seen 
 that tracts of consciousness formed of feelings produced by 
 external disturbances, are mostly distinguished by predomi- 
 nance of the relational element, involving clearness of mutual 
 limitation and strength of cohesion among the component 
 feelings; and we have seen that, contrariwise, the feelings pro- 
 duced by internal disturbances, peripheral and central are 
 mostly distnguished by comparative want of the relational 
 element, involving proportionate defect of mutual limitation 
 and cohesion. We have now to observe that the tracts of con- 
 sciousness thus broadly contrasted, are, by consequence, broadly 
 contrasted in the respect that, in the one case, the component 
 feelings can unite into coherent and well-defined clusters, while, 
 in the other case, they cannot so unite. 
 
 The state of consciousness produced by an object seen is 
 composed of sharply-outlined lights, shades, and colours, and 
 the co-existent feelings and relations entering into one of these 
 groups form an indissoluble whole. To a considerable degree, 
 successive visual feelings cling together in defined groups. As 
 most of them are caused by moving objects more or less com-
 
 THE PRINCIPLES OF PSYCHOLOGY 517 
 
 plex, it is difficult to trace this clustering of them in sequence 
 apart from their clustering in co-existence. But if we take the 
 case of a bird that suddenly flies past close to a window out of 
 which we are looking, it is manifest that the successive feelings 
 form a consciousness of its line of movement so defined and 
 coherent that we know, without having moved the eyes, what 
 was its exact course. The clustering of auditory 
 
 feelings, comparatively feeble among those occurring simul- 
 taneously, is comparatively strong among those occurring suc- 
 cessively. Hence the consolidated groups of sounds which we 
 know in consciousness as words. Hence the chains of notes 
 which we remember as musical phrases. The clustering 
 
 of tactual feelings in relations of co-existence, though by no 
 means so decided as the clustering of co-existent visual feelings, 
 either in the extent or complexity of the clusters or the firmness 
 with which their components are united, is nevertheless consid- 
 erable. When the hand is laid on some small object, as a key, a 
 number of impressions may be distinguished as separate though 
 near, one another; but while their mutual relations are so far 
 fixed that approximate limits within which they exist are 
 known, they do not constitute anything like such a fixed and 
 defined group as those given by vision of the key. This imper- 
 fect clustering in co-existence is accompanied by imperfect clus- 
 tering in sequence. The successive feelings produced by a fly 
 creeping over the hand, hold together strongly enough and 
 definitely enough to constitute a consciousness of its general 
 movement as being towards the wrist or from the wrist, across 
 fr >m right to left or from left to right; but they do not form a 
 consciousness of its exact course. Tastes unite only 
 
 into very simple and incoherent clusters in co-existence; while 
 in sequence they scarcely unite at all. And the like is true of 
 smells. 
 
 Such capability of clustering as is displayed by the peri- 
 pherally-initiated feelings caused by internal disturbances, oc- 
 curs among those accompanying the movements of muscles. 
 But, along with the comparative vagueness of limitation and 
 want of strong cohesion which characterize these feelings, there
 
 Si8 HERBERT SPENCER 
 
 goes a comparative indistinctness of the clusters. Though the 
 nervous acts of which muscular motions are results, combine 
 into groups with much precision, yet the combination of them, 
 at first feeble, becomes strong only by repetition. And as the 
 repetition which makes the combination strong, makes it to the 
 same extent automatic, the concomitant feelings become less 
 and less distinct, and fade from consciousness as fast as they 
 unite. How, in muscular acts, complete clustering and uncon- 
 sciousness go together, is seen in the fact that consciousness 
 impedes clustered muscular acts. After having many times 
 gone through the series of compound movements required, it is 
 possible to walk across the room in the dark and lay hold of the 
 handle of the door so long, that is, as the movements are 
 gone through unthinkingly. If they are consciously made, 
 failure is almost certain. Of the further class of feel- 
 
 ings initiated within the body, including appetites, pains, &c., 
 it is scarcely needful to say that there is among them no forma- 
 tion of coherent groups. Their great indefiniteness of limita- 
 tion and accompanying want of cohesion, forbid unions of them, 
 either simultaneous or successive. 
 
 Obviously the emotions are characterized by a like want of 
 combining power. A confused and changing chaos is produced 
 by any of them which co-exist. In fact, the absence among 
 them of capacity for uniting, is as marked as its presence 
 among those visual feelings with which we set out. 
 
 71 . We come now to more complex manifestations of these 
 general contrasts. In tracts of consciousness where the rela- 
 tional element predominates, and where the clustering of feel- 
 ings is consequently decided, the clusters themselves enter into 
 relations one with another. Grouped feelings, together with 
 the relations uniting them, are fused into wholes which, com- 
 porting themselves as single feelings do, combine with other 
 such consolidated groups in definite relations; and even groups 
 of groups, similarly fused, become in like manner limited by, 
 and coherent with, other groups of groups. Conversely, in 
 tracts of consciousness where the relations are few and vague, 
 nothing of the kind takes place.
 
 THE PRINCIPLES OF PSYCHOLOGY 519 
 
 It is among the visual feelings, above all others multitudin- 
 ous, definite, and coherent in their relations, that this com- 
 pound clustering is carried to the greatest extent. Along with 
 the ability to form that complex consciousness of lights, shades, 
 and colours, joined in relative positions, which constitute a 
 man as present to sight, there goes the ability to form a con- 
 sciousness of two men in a definite and coherent relation of 
 position there goes the ability to form a consciousness 
 of a crowd of such men; nay, two or more such crowds 
 may be mentally combined. The aggregate of definitely- 
 related visual feelings known as a house, itself aggregates 
 with others such to form the consciousness of a street, and the 
 streets to form the consciousness of a town. Though the com- 
 pound clustering of visual feelings in sequence is not so distinct 
 or so strong, it is still very marked. Numerous complicated 
 images produced by objects seen in succession, hang together 
 in consciousness with considerable tenacity. There is 
 
 little, if any, clustering of clusters among the simultaneous 
 auditory feelings. But among the successive auditory feelings 
 there are definite and coherent combinations of groups with 
 groups. The fused set of sounds we call a word, unites with 
 many others such into a sentence. In some minds these clus- 
 ters of clusters of successive sounds again cluster very defin- 
 itely and coherently: many successive sentences are, as we say, 
 accurately remembered. And similarly, musical phrases will 
 cling together into a long and elaborate melody. Among 
 
 the tactual feelings this compound clustering is scarcely trace- 
 able, either in space or time; and there is not the remotest 
 approach to it in the olfactory and gustatory feelings. 
 
 For form's sake it is needful to say that these higher degrees 
 of mental composition are entirely wanting among the inter- 
 nally-initiated feelings. Only among those which accompany 
 muscular motion is there any approach to it; and here the 
 compound clustering, like the simple clustering, entails pro- 
 gressing unconsciousness. 
 
 72. One more kindred trait of composition must be set
 
 520 HERBERT SPENCER 
 
 down. Thus far we have observed only the degrees of mutual 
 limitation, of cohesion, and of complex combining power, 
 among feelings within each order. It remains to observe the 
 extent to which feelings of one order enter into relations with 
 those of another, and the consequent amounts of their mutual 
 limitations and of their combining powers. To trace out these 
 at all fully would carry us into unmanageable detail. We must 
 confine ourselves to leading facts. 
 
 Feelings of different orders do not limit one another as clearly 
 as feelings of the same order do. The clustered colours pro- 
 duced by an object at which we look are but little interfered 
 with by a sound: the sound does not put any appreciable 
 boundary to them in consciousness, but serves merely to di- 
 minish their dominance in consciousness. Neither the combined 
 noises which make up a conversation at table, nor the impres- 
 sions received through the eyes from the dishes on the table, 
 are excluded from the mind by the accompanying tactual feel- 
 ings and tastes and smells, as much as colours are excluded by 
 colours, sounds by sounds, tastes by tastes, or one tactual feeling 
 by another. Of sensations arising within the body, and still 
 more of emotions, it may be said that, unless intense, they dis- 
 turb but slightly the sensations otherwise arising. It would 
 almost seem as though a sensation of colour, a sensation of 
 sound, and a pleasurable emotion produced by the sound, 
 admit of being superposed in consciousness with but little mu- 
 tual obscuration. Doubtless in most cases two simple feelings, 
 or two clustered feelings of different orders, put bounds to one 
 another in time if not in space: there is an extremely rapid 
 extrusion of each by the other rather than a continuous pres- 
 ence of either. But it is manifest that these alternating ex- 
 trusions, partial or complete, by feelings of different orders, are 
 less distinct than the extrusion of one another by feelings of the 
 same order. 
 
 It is a correlative truth that feelings of different orders cohere 
 with one another less strongly than do feelings of the same 
 order. The impressions which make up the visual conscious- 
 ness of an object, hang together more firmly than the group of
 
 THE PRINCIPLES OF PSYCHOLOGY 521 
 
 them does with the group of sounds making up the name of the 
 object. The notes composing a melody have a stronger ten- 
 dency to drag one another into consciousness than any one, or 
 all of them, have to drag into consciousness the sights along 
 with which they occurred: these last may or may not cohere 
 with them; but the following of one note by the next is often 
 difficult to prevent. Similarly, though there is considerable 
 cohesion between the visual sensations produced by an orange 
 and the taste or smell of the orange, yet it is quite usual to have 
 a visual consciousness of an orange without its taste or its smell 
 arising in consciousness; while it is scarcely possible to have 
 before the mind one of its apparent characters unaccompanied 
 by other apparent characters. 
 
 A further fact of moment must be added. The feelings of 
 different orders which enter into definite relations and cohere 
 most strongly, are those among which there is a predominance 
 of the relational elements; and there is an especial facility of 
 combination between those feelings of different orders which 
 are respectively held together by relations of the same order. 
 Thus the co-existent visual feelings, most relational of all, enter 
 into very definite and coherent relations with co-existent tact- 
 ful feelings. To the group of lights and shades an object yields 
 to the eyes, there attaches itself very strongly the group of im- 
 pressions produced by touching and grasping the object. Next 
 in order of strength are the connections between sensations 
 received through the eyes and those received through the ears ; 
 or rather between clusters of the one and clusters of the 
 other. But though the feelings clustered in co-existence that 
 form the visual consciousness of anything, are linked with 
 much strength to the feelings clustered in sequence that form 
 the consciousness of its name; yet, probably because the feelings 
 forming the one cluster not only differ in kind from those form- 
 ing the other but are held together by relations of a different 
 order, the cohesion of the two clusters is not so strong. As we 
 descend towards the unrelational feelings we find that this com- 
 bining power of class with class decreases. Between tastes and 
 smells and certain visceral sensations, such as hunger and
 
 522 HERBERT SPENCER 
 
 nausea, there is, indeed, a considerable aptitude to cohere. 
 But after admitting exceptions, it remains true on the average 
 that the extremely un-relational states of consciousness of 
 different orders, connect but feebly with one another and with 
 the extremely-relational states of consciousness. 
 
 73. Thus far we have proceeded as though Mind were 
 composed entirely of the primary or vivid feelings, and the 
 relations among them; ignoring the secondary or faint feelings. 
 Or if, as must be admitted, there has been a tacit recognition of 
 these secondary feelings in parts of the foregoing sections which 
 deal with the relations and cohesions of feelings in sequence 
 (since in a sequence of feelings those which have passed have 
 become faint, and only the one present is vivid) ; yet there has 
 been no avowed recognition of them as components of Mind 
 different from, though closely allied with, the primary feelings. 
 We must now specially consider them and the part they play. 
 
 The cardinal fact to be noted as of co-ordinate importance 
 with the facts above noted, is that while each vivid feeling is 
 joined to, but distinguished from, other vivid feelings, simul- 
 taneous or successive, it is joined to, and identified with, faint 
 feelings that have resulted from foregoing similar vivid feelings. 
 Each particular colour, each special sound, each sensation of 
 touch, taste, or smell, is at once known as unlike other sensa- 
 tions that limit it in space or time, and known as like the faint 
 forms of certain sensations that have preceded it in time - 
 unites itself with foregoing sensations from which it does not 
 differ in quality but only in intensity. 
 
 On this law of composition depends the orderly structure of 
 Mind. In its absence there could be nothing but a perpetual 
 kaleidoscopic change of feelings an ever-transforming pre- 
 sent without past or future. It is because of this tendency 
 which vivid feelings have severally to cohere with the faint 
 forms of all preceding feelings like themselves, that there arise 
 what we call ideas. A vivid feeling does not by itself constitute 
 a unit of that aggregate of ideas entitled knowledge. Nor does 
 a single faint feeling constitute such a unit. But an idea, or unit
 
 THE PRINCIPLES OF PSYCHOLOGY 523 
 
 of knowledge, results when a vivid feeling is assimilated to, or 
 coheres with, one or more of the faint feelings left by such vivid 
 feelings previously experienced. From moment to moment the 
 feelings that constitute consciousness segregate each be- 
 coming fused with the whole series of others like itself that have 
 gone before it ; and what we call knowing each feeling as such or 
 such, is our name for this act of segregation. 
 
 The process so carried on does not stop with the union of 
 each feeling, as it occurs, with the faint forms of all preceding 
 like feelings. Clusters of feelings are simultaneously joined 
 with the faint forms preceding like clusters. An idea of an ob- 
 ject or act is composed of groups of similar and similarly- 
 related feelings that have arisen in consciousness from time 
 to time, and have formed a consolidated series of which the 
 members have partially or completely lost their individuali- 
 ties. 
 
 This union of present clustered feelings with past clustered 
 feelings is carried to a much greater degree of complexity. 
 Groups of groups coalesce with kindred groups of groups that 
 preceded them; and in the higher types of Mind, tracts of con- 
 sciousness of an excessively composite character are produced 
 after the same manner. 
 
 To complete this general conception it is needful to say that 
 as with feelings, so with the relations between feelings. Parted 
 so far as may be from the particular pairs of feelings and pairs 
 of groups of feelings they severally unite, relations themselves 
 are perpetually segregated. From moment to moment relations 
 are distinguished from one another in respect of the degrees of 
 contrast between their terms and the kinds of contrast between 
 their terms; and each relation, while distinguished from various 
 concurrent relations, is assimilated to previously-experienced 
 relations like itself. Thus result ideas of relations as those of 
 strong contrast or weak contrast, of descending intensity or 
 ascending intensity, of homogeneity of kind or heterogeneity of 
 kind. Simultaneously occurs a segregation of a different species. 
 Each relation of co-existence is classed with other like relations 
 of co-existence and separated from relations of co-existence that
 
 524 HERBERT SPENCER 
 
 are unlike it; and a kindred classing goes on among relations of 
 sequence. Finally, by a further segregation, are formed that 
 consolidated abstract of relations of co-existence which we 
 know as Space, and that consolidated abstract of relations of 
 sequence which we know as Time. This process, here briefly 
 indicated merely to show its congruity with the general process 
 of composition, cannot be explained at length : the elucidation 
 must come hereafter. 
 
 74. And now having roughly sketched the composition of 
 Mind having, to preserve clearness of outline, omitted de- 
 tails and passed over minor qualifications; let me go on to indi- 
 cate the essential truth which it is a chief purpose of this chap- 
 ter to bring into view the truth that the method of composi- 
 tion remains the same throughout the entire fabric of Mind 
 from the formation of its simplest feelings up to the formation 
 of- those immense and complex aggregates of feelings which 
 characterize its highest developments. 
 
 In the last chapter we saw that what is objectively a wave of 
 molecular change propagated through a nerve-centre, is sub- 
 jectively a unit of feeling, akin in nature to what we call a nerv- 
 ous shock. In one case we found conclusive proof that when a 
 rapid succession of such waves yield a rapid succession of such 
 units of feeling, there results the continuous feeling known as a 
 sensation; and that the quality of the feeling changes when 
 these waves and corresponding units of feeling recur with a dif- 
 ferent rapidity. Further, it was shown that by unions among 
 simultaneous series of such units recurring at unlike rates, 
 countless other seemingly-simple sensations are produced. And 
 we inferred that what unquestionably holds among these 
 primary feelings of one order, probably holds among primary 
 feelings of all orders. To what does this conclusion amount, 
 expressed in another way? It amounts to the conclusion that 
 one of these feelings which, as introspectively contemplated, 
 appears uniform, is really generated by the perpetual assimila- 
 tion of a new pulse of feeling to pulses of feeling immediately 
 preceding it: the sensation is constituted by the linking of each
 
 THE PRINCIPLES OF PSYCHOLOGY 525 
 
 vivid pulse as it occurs, with the series of past pulses that were 
 severally vivid but have severally become faint. And what, 
 otherwise stated, is the conclusion that compound sensations 
 result from unions among different concurrent series of such 
 pulses? It is that while the component pulses of each series are, 
 as they occur, severally assimilated to, or linked with, preced- 
 ing pulses of their own kind, they are also severally combined 
 in some relation with the pulses of concurrent series; and the 
 compound sensation so generated is known as different from 
 other compound sensations of the same order, by' virtue of 
 some speciality in the relations among the concurrent series. 
 
 Consider now, under its most general form, the process of 
 composition of Mind described in foregoing sections. It is no 
 other than this same process carried out on higher and higher 
 platforms, with increasing extent and complication. As we 
 have lately seen, the feelings called sensations cannot of them- 
 selves constitute Mind, even when great numbers of various 
 kinds are present together. Mind is constituted only when each 
 sensation is assimilated to the faint forms of antecedent-like 
 sensations. The consolidation of successive units of feeling to 
 form a sensation, is paralleled in a larger way by the consolida- 
 tion of successive sensations to form what we call a knowledge 
 of the sensation as such or such to form the smallest separa- 
 ble portion of what we call thought, as distinguished from mere 
 confused sentiency. So too is it with the relations among those 
 feelings that occur together and limit one another in space or 
 time. Each of these relations, so long as it stands alone in expe- 
 rience with no antecedent like relations, is not fully cognizable 
 as a relation: it assumes its character as a component of intelli- 
 gence only when, by recurrence of it, there is produced a serial 
 aggregate of such relations. Observe further that while 
 
 each special sensation is raised into a proixmate constituent of 
 simple thought only by being fused with like predecessors, it 
 becomes a proximate constituent of compound thought by 
 simultaneously entering into relations of unlikeness with other 
 sensations which limit it in space or time; just as we saw that 
 the units or pulses that form simple sensations by serial union
 
 526 HERBERT SPENCER 
 
 with their kind, may simultaneously help to form complex sen- 
 sations by entering into relations of difference with units of 
 other kinds. The same thing obviously holds of the relations 
 themselves, that exist between these unlike sensations. And 
 thus it becomes manifest that the method by which simple sen- 
 sations, and the relations among them, are compounded into 
 states of definite consciousness, is essentially analogous to the 
 method by which primitive units of feeling are compounded into 
 sensations. 
 
 The next higher stage of mental composition shows us this 
 process repeating itself. The vivid cluster of related sensations 
 produced in us by a special object, has to be united with the 
 faint forms of clusters like it that have been before produced 
 by such objects. What we call knowing the object, is the as- 
 similation of this combined group of real feelings it excites, 
 with one or more preceding ideal groups which objects of the 
 same kind once excited ; and the knowledge is clear only when 
 the series of ideal groups is long. Equally does this 
 
 principle hold of the connexions, static and dynamic, between 
 each such special cluster and the special clusters generated by 
 other objects. Knowledge of the powers and habits of things, 
 dead and living, is constituted by assimilating the more or less 
 complex relations exhibited by their actions in space and time 
 with other such complex relations. If we cannot so assimilate 
 them, or parts of them, we have no knowledge of their actions. 
 
 That the same law of composition continues without definite 
 limit through tracts of higher consciousness, formed of clusters 
 of clusters of feelings held together by relations of an extremely 
 involved kind, scarcely needs adding. 
 
 75. How clearly the evolution of Mind, as thus traced 
 through ascending stages of composition, conforms to the laws 
 of Evolution in general, will be seen as soon as it is said. We 
 will glance at the correspondence under each of its leading 
 aspects. 
 
 Evolution is primarily a progressing integration; and 
 throughout this chapter, as well as the last, progressing inte-
 
 THE PRINCIPLES OF PSYCHOLOGY 527 
 
 gration has thrust itself upon us as the fundamental fact in 
 mental evolution. We came upon it quite unexpectedly in the 
 conclusion that a sensation is .an integrated series of nervous 
 shocks or units of feeling; and in the further conclusion that by 
 integration of two or more such series, compound sensations are 
 formed. We have lately seen that by an integration of succes- 
 sive like sensations, there arises the knowledge of a sensation 
 as such or such; and that each sensation as it occurs, while 
 thus integrated with its like, also unites into an aggregate with 
 other sensations that limit it in space or time. And we have 
 similarly seen that the integrated clusters resulting, enter into 
 higher integrations of both these kinds; and so on to the 
 end. The significance of these facts will be appreciated 
 
 when it is remembered that the tracts of consciousness in 
 which integration is undecided, are tracts of consciousness 
 hardly included in what we commonly think of as Mind ; and 
 that the tracts of consciousness presenting the attributes of 
 Mind in the highest degree, are those in which the integration 
 is carried furthest. Hunger, thirst, nausea, and visceral feelings 
 in general, as well as feelings of love, hatred, anger, &c., which 
 cohere little with one another and with other feelings, and thus 
 integrate but feebly into groups, are portions of consciousness 
 that play but subordinate parts in the actions we chiefly class as 
 mental. Mental actions, ordinarily so called, are nearly all 
 carried on in terms of those tactual, auditory, and visual feel- 
 ings, which exhibit cohesion, and consequent ability to inte- 
 grate, in so conspicuous a manner. Our intellectual operations 
 are indeed mostly confined to the auditory feelings (as inte- 
 grated into words) and the visual feelings (as integrated into 
 impressions and ideas of objects, their relations, and their 
 motions). After closing the eyes and observing how relatively- 
 immense is the part of intellectual consciousness that is sud- 
 denly shorn away, it will be manifest that the most developed 
 portion of perceptive Mind is formed of these visual feelings 
 which cohere so rigidly, which integrate into such large and nu- 
 merous aggregates, and which re-integrate into aggregates im- 
 mensely exceeding in their degree of composition all aggregates
 
 528 HERBERT SPENCER 
 
 formed by other feelings. And then, on rising to what we for 
 convenience distinguish as rational Mind, we find the integra- 
 tion taking a still wider reach. 
 
 The ascending phases of Mind show us no less conspicu- 
 ously, the increasing heterogeneity of these integrated aggre- 
 gates of feelings. In the last chapter, we saw how sensations 
 that are all composed of units of one kind, are rendered hetero- 
 geneous by the combination and re-combination of such units 
 in multitudinous ways. We have lately seen that the portions 
 of consciousness occupied by the internal bodily feelings and by 
 the emotions, are, as judged by introspection, relatively very 
 simple or homogeneous: thirst is not made up of contrasted 
 parts, nor can we separate a gust of passion into many distin- 
 guishable components. But on passing upwards to intellectual 
 consciousness, there meets us an increasing variety of kinds of 
 feelings present together. When we come to the auditory feel- 
 ings, which play so important a part in processes of thought, 
 we find that the groups of them are formed of many compon- 
 ents, and that those groups of groups used as symbols of pro- 
 positions are very heterogeneous. As before however with 
 integration, so where with heterogeneity, a far higher degree is 
 reached in that consciousness formed of visual feelings, which 
 is the most developed part of perceptive Mind. And much 
 more heterogeneous still are those tracts of consciousness dis- 
 tinguished as ratiocinative tracts, in which the multiform 
 feelings given us by objects through eyes, ears, and tactual 
 organs, nose, and palate, are formed into conceptions that 
 answer to the objects in all their attributes, and all their 
 activities. 
 
 With equal clearness does Mind display the further trait of 
 Evolution increase of definiteness. Both the centrally- 
 initiated feelings and the internal peripherally-initiated feel- 
 ings, which play so secondary a part in what we understand 
 as Mind, we found to be very vague very imperfectly lim- 
 ited by one another. Contrariwise, it was shown that the 
 mutual limitations are decided among those peripherally- 
 initiated feelings which, arising on the outer surface, enter
 
 THE PRINCIPLES OF PSYCHOLOGY 529 
 
 largely into our intellectual operations; and that the visual 
 feelings, which enter by far the most largely into our intel- 
 lectual operations, are not only by far the sharpest in their 
 mutual limitations, but form aggregates that are much more 
 definitely circumscribed than any others, and aggregates be- 
 tween which there exist relations much more definite than 
 those entered into by other aggregates. 
 
 Thus the conformity is complete. Mind rises to what are 
 universally recognized as its higher developments, in propor- 
 tion as it manifests the traits characterizing Evolution in gen- 
 eral (First Principles, 98-145). A confused sentiency, 
 formed of recurrent pulses of feeling having but little variety 
 of kind and but little combination, we may conceive as the 
 nascent Mind possessed by those low types in which nerves and 
 nerve-centres are not yet clearly differentiated from one an- 
 other, or from the tissues in which they lie. At a stage above 
 this, while yet the organs of the higher senses are rudimentary 
 and such nerves as exist are incompletely insulated, Mind is 
 present probably under the form of a few sensations, which, like 
 those yielded by our own viscera, are simple, vague, and inco- 
 herent. And from this upwards, the mental evolution exhibits 
 a differentiation of these simple feelings into the more numer- 
 ous kinds which the special senses yield; an ever-increasing 
 integration of such more varied feelings with one another and 
 with feelings of other kinds; an ever-increasing multiformity in 
 the aggregates of feelings produced ; and an ever-increasing dis- 
 tinctness of structure in such aggregates. That is to say, there 
 goes on subjectively a change "from an indefinite, incoherent 
 homogeneity to a definite, coherent heterogeneity;" parallel to 
 that redistribution of matter and motion which constitutes 
 Evolution as objectively displayed.
 
 JOHANNES MUELLER 
 
 (1801-1858) 
 
 ELEMENTS OF PHYSIOLOGY 
 
 Translated from the German* by 
 WILLIAM BALY 
 
 BOOK V. OF THE SENSES 
 THE GENERAL LAWS OF SENSATION 
 
 THE senses, by virtue of the peculiar properties of their 
 several nerves, make us acquainted with the states of our own 
 body, and they also inform us of the qualities and changes of 
 external nature, as far as these give rise to changes in the condi- 
 tion of the nerves. Sensation is a property common to all the 
 senses; but the kind ("modus"} of sensation is different in 
 each: thus we have the sensations of light, of sound, of taste, of 
 smell, and of feeling, or touch. By feeling, or touch, we under- 
 stand the peculiar kind of sensation of which the ordinary sen- 
 sitive nerves generally as, the nervus trigeminus, vagus, 
 ' glosso-pharyngeus, and the spinal nerves, are susceptible; 
 the sensations of itching, of pleasure and pain, of heat and cold, 
 and those excited by the act of touch in its more limited sense, 
 are varieties of this mode of sensation. That which through the 
 medium of our senses is actually perceived by the sensorium, is 
 indeed merely a property or change of condition of our nerves; 
 but the imagination and reason are ready to interpret the modi- 
 fications in the state of the nerves produced by external influ- 
 ences as properties of the external bodies themselves. This 
 
 * From J. Miiller's Handbuch dcr Physiologic des MenscTtcn fiir Vortesungen, 
 2 Bde. Coblenz, 1834-40. Reprinted from J. Miiller's Elements of Physiology, 
 translated by William Baly. London, 1837-42, vol. n.
 
 ELEMENTS OF PSYCHOLOGY 531 
 
 mode of regarding sensations has become so habitual in the case 
 of the senses which are more rarely affected by internal causes, 
 that it is only on reflection that we perceive it to be erroneous. 
 In the case of the sense of feeling or touch, on the contrary, 
 where the peculiar sensations of the nerves perceived by the 
 sensorium are excited as frequently by internal as by external 
 causes, it is easily conceived that the feeling of pain or pleasure, 
 for example, is a condition of the nerves, and not a property of 
 the things which excite it. This leads us to the consideration of 
 some general laws, a knowledge of which is necessary before 
 entering on the physiology of the separate senses. 
 
 I. In the first place, it must be kept in mind that external 
 agencies can give rise to no kind of sensation which cannot also be 
 produced by internal causes, exciting changes in the condition of 
 our nerves. 
 
 In the case of the sense of touch, this is at once evident. The 
 sensations of the nerves of touch (or common sensibility) are 
 those of cold and heat, pain and pleasure, and innumerable 
 modifications of these, which are neither painful nor pleasur- 
 able, but yet have the same kind of sensation as their element, 
 though not in an extreme degree. All these sensations are con- 
 stantly being produced by internal causes in all parts of our 
 body endowed with sensitive nerves ; they may also be excited 
 by causes acting from without, but external agencies are not 
 capable of adding any new element to their nature. The sensa- 
 tions of the nerves of touch are therefore states or qualities 
 proper to themselves, and merely rendered manifest by exciting 
 causes external or internal. The sensation of smell also may be 
 perceived independently of the application of any odorous sub- 
 stance from without, the nerve of smell being thrown by an in- 
 ternal cause into the condition requisite for the production of 
 the sensation. This perception of the sensation of odours with- 
 out an external exciting cause, though not of frequent occur- 
 rence, has been many times observed in persons of an irritable 
 nervous system ; and the sense of taste is probably subject to the 
 same affection, although it would be always difficult to deter- 
 mine whether the taste might not be owing to a change in the
 
 53 2 JOHANNES MUELLER 
 
 qualities of the saliva or mucus of the mouth ; the sensation of 
 nausea, however, which belongs to the sensations of taste, is 
 certainly very often perceived as the result of a merely internal 
 affection of the nerves. The sensations of the sense of vision, 
 namely, colour, light, and darkness, are also perceived inde- 
 pendently of all external exciting cause. In the state of the 
 most perfect freedom from excitement, the optic nerve has no 
 other sensation than that of darkness. The excited condition 
 of the nerve is manifested, even while the eyes are closed, by the 
 appearance of light, or luminous flashes, which are mere sensa- 
 tions of the nerve, and not owing to the presence of any matter 
 of light, and consequently are not capable of illuminating any 
 surrounding objects. Every one is aware how common it is to 
 see bright colours while the eyes are closed, particularly in the 
 morning when the irritability of the nerves is still considerable. 
 These phenomena are very frequent in children after waking 
 from sleep. Through the sense of vision, therefore, we receive 
 from external nature no impressions which we may not also 
 experience from internal excitement of our nerves; and it is 
 evident that a person blind from infancy in consequence of 
 opacity of the transparent media of the eye, must have a per- 
 fect internal conception of light and colours, provided the retina 
 and optic nerve be free from lesion. The prevalent notions with 
 regard to the wonderful sensations supposed to be experienced 
 by persons blind from birth when their sight is restored by oper- 
 ation, are exaggerated and incorrect. The elements of the sen- 
 sation of vision, namely, the sensations of light, colour, and 
 darkness, must have been previously as well known to such 
 persons as to those of whom the sight has always been perfect. 
 If, moreover, we imagine a man to be from his birth surrounded 
 merely by external objects destitute of all variety of colours, so 
 that he could never receive the impressions of colours from 
 without, it is evident that the sense of vision might neverthe- 
 less have been no less perfect in him than in other men; for 
 light and colours are innate endowments of his nature, and 
 require merely a stimulus to render them manifest. 
 The sensations of hearing also are excited as well by internal
 
 ELEMENTS OF PSYCHOLOGY 533 
 
 as by external causes; for, whenever the auditory nerve is in a 
 state of excitement, the sensations peculiar to it, as the sounds 
 of ringing, humming, &c. are perceived. It is by such sensations 
 that the diseases of the auditory nerve manifest themselves; 
 and, even in less grave, transient affections of the nervous sys- 
 tem, the sensations of humming and ringing in the ears afford 
 evidence that the sense of hearing participates in the disturb- 
 ance. 
 
 No further proof is wanting to show, that external influences 
 give rise in our senses to no other sensations, than those which 
 may be excited in the corresponding nerves by internal causes. 
 
 II. The same internal cause excites in the different senses dif- 
 ferent sensations; in each sense the sensations peculiar to it. 
 
 One uniform internal cause acting on all the nerves of the 
 senses in the same manner, is the accumulation of blood in the 
 capillary vessels of the nerve, as in congestion and inflamma- 
 tion. This uniform cause excites in the retina, while the eyes 
 are closed, the sensation of light and luminous flashes; in the 
 auditory nerve, humming and ringing sounds; and in the 
 nerves of feeling, the sensation of pain. In the same way, also, 
 a narcotic substance introduced into the blood excites in the 
 nerves of each sense peculiar symptoms; in the optic nerves the 
 appearance of luminous sparks before the eyes; in the auditory 
 nerves, " tinnitus aurium;" and in the common sensitive nerves 
 the sensation of ants creeping over the surface. 
 
 III. The same external cause also gives rise to different sensa- 
 tions in each sense, according to the special endowments of its 
 nerve. 
 
 The mechanical influence of a blow, concussion, or pressure 
 excites, for example, in the eye the sensation of light and 
 colours. It is well known that by exerting pressure upon the 
 eye, when the eyelids are closed, we can give rise to the appear- 
 ance of a luminous circle ; by more gentle pressure the appear- 
 ance of colours may be produced, and one colour may be made 
 to change to another. Children, waking from sleep before day- 
 light, frequently amuse themselves with these phenomena. The 
 light thus produced has no existence external to the optic nerve,
 
 534 JOHANNES MUELLER 
 
 it is merely a sensation excited in it. However strongly we press 
 upon the eye in the dark, so as to give rise to the appearance of 
 luminous flashes, these flashes, being merely sensations, are 
 incapable of illuminating external objects. Of this any one may 
 easily convince himself by experiment. I have in repeated trials 
 never been able, by means of these luminous flashes in the eye, 
 to recognise in the dark the nearest objects, or to see them bet- 
 ter than before; nor could another person, while I produced by 
 pressure on my eye the appearance of brilliant flashes, perceive 
 in it the slightest trace of real light. 
 
 A mechanical influence excites also peculiar sensations of the 
 auditory nerve; at all events, it has become a common saying, 
 " to give a person what will make his ears ring," or " what will 
 make his eyes flash fire," or "what will make him feel "; so that 
 the same cause, a blow, produces in the nerves of hearing, 
 sight, and feeling, the different sensations proper to these 
 senses. It has not become a part of common language that a 
 blow shall be given which will excite the sense of smell, or of 
 taste; nor would such sayings be correct; yet mechanical irri- 
 tation of the soft palate, of the epiglottis and root of the tongue, 
 excites the sensation of nausea. The actions of sonorous bodies 
 on the organ of hearing is entirely mechanical. A sudden me- 
 chanical impulse of the air upon the organ of hearing produces 
 the sensation of a report of different degrees of intensity accord- 
 ing to the violence of the impulse, just as an impulse upon thi 
 organ of vision gives rise to the sensation of light. If the action 
 of the mechanical cause on the organ of hearing be of continued 
 duration, the sound is also continued; and when caused by a 
 rapid succession of uniform impulses, or vibrations, it has a 
 musical character. If we admit that the matter of light acts on 
 bodies by mechanical oscillation (the undulation theory), we 
 shall have another example of a mechanical influence, producing 
 different effects on different senses. These undulations, which 
 produce in the eye the sensation of light, have no such effects 
 on other senses; but in the nerves of feeling they produce the 
 sensation of warmth.
 
 ELEMENTS OF PSYCHOLOGY 535 
 
 The stimulus of electricity may serve as a second example, of a 
 uniform cause giving rise in different nerves of sense to different 
 sensations. A single pair of plates of different metals applied so 
 as to include the eye within the circle, excites the sensation of a 
 bright flash of light when the person experimented upon is in a 
 dark room; and, even though the eye do not lie within the cir- 
 cle, if it be not distant from it, as, for example, when one of 
 the plates is applied to one of the eyelids, and the other to the 
 interior of the mouth, the same effect will be produced, 
 owing to a part of the current of electricity being diverted to the 
 eye. A more intense electric stimulus gives rise to more intense 
 sensations of light. In the organ of hearing, electricity excites 
 the sensation of sound. Volta states that, while his ears were 
 included between the poles of a battery of forty pairs of plates, 
 he heard a hissing and pulsatory sound, which continued as long 
 as the circle was closed.* Ritter perceived a sound like that of 
 the fiddle G at the moment of the closure of the galvanic circle. 
 
 The electricity of friction, developed by the electrical ma- 
 chine, excites in the olfactory nerves the odour of phosphorus. 
 The application of plates of different metals to the tongue, 
 gives rise to an acid or a saline taste, according to the length of 
 the plates which are applied one above, and the other beneath 
 the tongue. The facts detailed with regard to the other senses 
 are sufficient to show that these latter phenomena cannot be 
 attributed to decomposition of the salts of the saliva. 
 
 The effects of the action of electricity on the nerves of com- 
 mon sensation or feeling, are neither the sensation of light, of 
 sound, of smell, nor of taste, but those proper to the nerves of 
 feeling, namely, the sensations of pricking, of a blow, &c. 
 
 Chemical influences also probably produce different effects 
 on different nerves of sense. We have, of course, but few 
 facts illustrating their action on these nerves; but we know that 
 in the sensitive nerves of the skin they excite the different kinds 
 of common sensation, as the sensations of burning, pain, and 
 heat; in the organ of taste, sensations of taste; and, when vola- 
 tile, in the nerves of smell, the sensations of odours. Without 
 
 * Philos. Transact. 1800, p. 427.
 
 536 JOHANNES MUELLER 
 
 the infliction of great injury on the textures, it is impossible to 
 apply chemical agents to the nerves of the higher senses, sight 
 and hearing, except through the medium of the blood. Chem- 
 ical substances introduced into the blood act on every nerve of 
 sense, and excite in each a manifestation of its properties. 
 Hence the internal sensations of light and sound, which are well 
 known to result from the action of narcotics. 
 
 IV. The peculiar sensations of each nerve of sense can be excited 
 by several distinct causes internal and external. 
 
 The facts on which this statement is founded have been 
 already mentioned; for we have seen that the sensation of light 
 in the eye is excited: 
 
 1. By the undulations or emanations which from their action 
 on the eye are called light, although they have many other 
 actions than this; for instance, they effect chemical changes, 
 and are the means of maintaining the organic processes in 
 plants. 
 
 2. By mechanical influences; as concussion, or a blow. 
 
 3. By electricity. 
 
 4. By chemical agents, such as narcotics, digitalis, &c. which, 
 being absorbed into the blood, give rise to the appearance of 
 luminous sparks, &c. before the eyes independently of any 
 external cause. 
 
 5. By the stimulus of the blood in the state of congestion. 
 The sensation of sound may be excited in the auditory nerve: 
 
 1. By mechanical influences, namely, by the vibrations of 
 sonorous bodies imparted to the organ of hearing through the 
 intervention of media capable of propagating them. 
 
 2. By electricity. 
 
 3. By chemical influences taken into the circulation; such as 
 the narcotics, or alterantia nervina. 
 
 4. By the stimulus of the blood. 
 
 The sensation of odours may be excited in the olfactory 
 nerves : 
 
 1. By chemical influences of a volatile nature, odorous 
 substances. 
 
 2. By electricity.
 
 ELEMENTS OF PSYCHOLOGY 537 
 
 The sensation of taste may be produced: 
 
 1. By chemical influences acting on the gustatory nerves 
 either from without or through the medium of the blood; for, 
 according to Magendie, dogs taste milk injected into their 
 blood-vessels, and begin to lap with their tongue. 
 
 2. By electricity. 
 
 3. By mechanical influences; for we must refer to taste the 
 sensation of nausea produced by mechanically irritating the 
 velum palati, epiglottis, and root of the tongue. 
 
 The sensations of the nerves of touch or feeling are excited: 
 
 1. By mechanical influences; as sonorous vibrations, and 
 contact of any kind. 
 
 2. By chemical influences. 
 
 3. By heat. 
 
 4. By electricity. 
 
 5. By the stimulus of the blood. 
 
 V. Sensation consists in the sensorium receiving through the 
 medium of the nerves, and as the result of the action of an external 
 cause, a knowledge of certain qualities or conditions, not of external 
 bodies, but of the nerves of sense themselves; and these qualities of 
 the nerves of sense are in all different, the nerve of each sense having 
 its own peculiar quality or energy. 
 
 The special susceptibility of the different nerves of sense for 
 certain influences, as of the optic nerve for light, of the 
 auditory nerve for vibrations, and so on, was formerly 
 attributed to these nerves having each a specific irritability. 
 But this hypothesis is evidently insufficient to explain all the 
 facts. The nerves of the senses have assuredly a specific irri- 
 tability for certain influences; for many stimuli, which exert 
 a violent action upon one organ of sense, have little or no effect 
 upon another: for example, light, or vibrations so infinitely 
 rapid as those of light, act only on the nerves of vision and 
 common sensation; slower vibrations, on the nerves of hearing 
 and common sensation, but not upon those of vision; odorous 
 substances only upon the olfactory nerves. The external stim- 
 uli must therefore be adapted to the organ of sense must be 
 "homogeneous:" thus light is the stimulus adapted to the
 
 538 JOHANNES MUELLER 
 
 nerve of vision; while vibrations of less rapidity, which act upon 
 the auditory nerve, are not adapted to the optic nerve, or are 
 indifferent to it; for if the eye be touched with a tuning-fork 
 while vibrating, a sensation of tremours is excited in the con- 
 junctiva, but no sensation of light. We have seen, however, 
 that one and the same stimulus, as electricity, will produce dif- 
 ferent sensations in the different nerves of the senses; all the 
 nerves are susceptible of its action, but the sensations in all are 
 different. The same is the case with other stimuli, as chemical 
 and mechanical influences. The hypothesis of a specific irrita- 
 bility of the nerves of the senses for certain stimuli, is therefore 
 insufficient; and we are compelled to ascribe, with Aristotle, pe- 
 culiar energies to each nerve, energies which are vital quali- 
 ties of the nerve, just as contractility is the vital property of 
 muscle. The truth of this has been rendered more and more 
 evident in recent times by the investigation of the so-called 
 "subjective" phenomena of the senses by Elliot, Darwin, Rit- 
 ter, Goethe, Purkinje, and Hjort. Those phenomena of the 
 senses, namely, are now styled " subjective," which are pro- 
 duced, not by the usual stimulus adapted to the particular 
 nerve of sense, but by others which do not usually act upon it. 
 These important phenomena were long spoken of as "illusions 
 of the senses," and have been regarded in an erroneous point of 
 view; while they are really true actions of the senses, and must 
 be studied as fundamental phenomena in investigations into 
 their nature. 
 
 The sensation of sound, therefore, is the peculiar "energy" 
 or "quality" of the auditory nerve; the sensation of light and 
 colours that of the optic nerve; and so of the other nerves of 
 sense. An exact analysis of what takes place in the production 
 of a sensation would of itself have led to this conclusion. The 
 sensations of heat and cold, for example, make us acquainted 
 with the existence of the imponderable matter of caloric, or of 
 peculiar vibrations in the vicinity of our nerves of feeling. But 
 the nature of this caloric cannot be elucidated by sensation, 
 which is in reality merely a particular state of our nerves; it 
 must be learnt by the study of the physical properties of this
 
 ELEMENTS OF PSYCHOLOGY 539 
 
 agent, namely, of the laws of its radiation, its development 
 from the latent state, its property of combining with and pro- 
 ducing expansion of other bodies, &c. All this again, however, 
 does not explain the peculiarity of the sensation of warmth as 
 a condition of the nerves. The simple fact devoid of all theory 
 is this, that warmth, as a sensation, is produced whenever the 
 matter of caloric acts upon the nerves of feeling; and that cold 
 as a sensation, results from this matter of caloric being ab- 
 stracted from a nerve of feeling. 
 
 So, also, the sensation of sound is produced when a certain 
 number of impulses or vibrations are imparted, within a certain 
 time, to the auditory nerve: but sound, as we perceive it, is a 
 very different thing from a succession of vibrations. The vibra- 
 tions of a tuning-fork, which to the ear give the impression of 
 sound, produce in a nerve of feeling or touch the sensation of 
 tickling; something besides the vibrations must consequently 
 be necessary for the production of the sensation of sound, and 
 that something is possessed by the auditory nerve alone. Vision 
 is to be regarded in the same manner. A difference in the in- 
 tensity of the action of the imponderable agent, light, causes an 
 inequality of sensation at different parts of the retina : whether 
 this action consists in impulses or undulations, (the undulation 
 theory,) or in an infinitely rapid current of imponderable mat- 
 ter, (the emanation theory,) is a question here of no importance. 
 The sensation of moderate light is produced where the action of 
 the imponderable agent on the retina is not intense; of bright 
 light where its action is stronger, and of darkness or shade 
 where the imponderable agent does not fall ; and thus results a 
 luminous image of determinate form according to the distribu- 
 tion of the parts of the retina differently acted on. Colour is 
 also a property of the optic nerve; and when excited by external 
 light, arises from the peculiarity of the so-called coloured rays, 
 or of the oscillations necessary for the production of the impres- 
 sion of colour, a peculiarity, the nature of which is not at 
 present known. The nerves of taste and smell are capable of 
 being excited to an infinite variety of sensations by external 
 causes) but each taste is due to a determinate condition of the
 
 540 JOHANNES MUELLER 
 
 nerve excited by the external cause; and it is ridiculous to say 
 that the property of acidity is communicated to the sensorium 
 by the nerve of taste, while the acid acts equally upon the nerves 
 of feeling, though it excites there no sensation of taste. 
 
 The essential nature of these conditions of the nerves, by 
 virtue of which they see light and hear sound, the essential 
 nature of sound as a property of the auditory nerve, and of light 
 as a property of the optic nerve, of taste, of smell, and of feel- 
 ing, remains, like the ultimate causes of natural phenomena 
 generally, a problem incapable of solution. Respecting the na- 
 ture of the sensation of the colour "blue," for example, we can 
 reason no farther; it is one of the many facts which mark the 
 limits of our powers of mind. It would not advance the ques- 
 tion to suppose the peculiar sensations of the different senses 
 excited by one and the same cause, to result from the propaga- 
 tion of vibrations of the nervous principle of different rapidity 
 to the sensorium. Such an hypothesis, if at all tenable, would 
 find its first application in accounting for the different sensa- 
 tions of which a single sense is susceptible; for example, in ex- 
 plaining how the sensorium receives the different impressions 
 of blue, red, and yellow, or of an acute and a grave tone, or of 
 painful and pleasurable sensations, or of the sensations of heat 
 and cold, or of the tastes of bitter, sweet, and acid. It is only 
 with this application that the hypothesis 'is worthy of regard: 
 tones of different degrees of acuteness are certainly produced by 
 vibrations of sonorous bodies of different degrees of rapidity ; and 
 a slight contact of a solid body, which singly excites in a nerve 
 of common sensation merely the simple sensation of touch, pro- 
 duces in the same nerve when repeated rapidly, as the vibra- 
 tions of a sonorous body, the feeling of tickling; so that possibly 
 a pleasurable sensation, even when it arises from internal causes 
 independently of external influences, is due to the rapidity of 
 the vibrations of the nervous principle in the nerves of feeling. 
 
 The accuracy of our discrimination by means of the senses 
 depends on the different manner in which the conditions of our 
 nerves are affected by different bodies; but the preceding con-
 
 541 
 
 siderations show us the impossibility that our senses can ever 
 reveal to us the true nature and essence of the material world. 
 In our intercourse with external nature it is always our own 
 sensations that we become acquainted with, and from them we 
 form conceptions of the properties of external objects, which 
 may be relatively correct; but we can never submit the nature 
 of the objects themselves to that immediate perception to 
 which the states of the different parts of our own body are sub- 
 jected in the sensorium. 
 
 VI. The nerve of each sense seems to be capable of one deter- 
 minate kind of sensation only, and not of those proper to the other 
 organs of sense; hence one nerve of sense cannot take the place and 
 perform the function of the nerve of another sense. 
 
 The sensation of each organ of sense may be increased in 
 intensity till it become pleasurable, or till it becomes disagree- 
 able, without the specific nature of the sensation being altered, 
 or converted into that of another organ of sense. The sensation 
 of dazzling light is an unpleasant sensation of the organ of vi- 
 sion ; harmony of colours, an agreeable one. Harmonious and 
 discordant sounds are agreeable and disagreeable sensations of 
 the organ of hearing. The organs of taste and smell have their 
 pleasant and unpleasant tastes and odours; the organ of touch 
 its pleasurable and painful feelings. It appears, therefore, that, 
 even in the most excited condition of an organ of sense, the sens- 
 ation preserves its specific character. It is an admitted fact 
 that the sensations of light, sound, taste, and odours, can be 
 experienced only in their respective nerves; but in the case of 
 common sensation this is not so evidently the case, for it is a 
 question whether the sensation of pain may not be felt in the 
 nerves of the higher senses, whether, for example, violent 
 irritation of the optic nerve may not give rise to the sensation 
 of pain. This question is difficult of solution. There are fila- 
 ments of the nerves of common sensation distributed in the 
 nerves of the other organs of sense: the nostrils are supplied 
 with nerves of common sensation from the second division of 
 the nervus trigeminus in addition to the olfactory nerves; the 
 tongue has common sensibility as well as taste, and may retain
 
 542 JOHANNES MUELLER 
 
 the one while it loses the other; the eye and organ of hearing 
 likewise are similarly endowed. 
 
 To determine this question, it is necessary to institute experi- 
 ments on the isolated nerves of special sense themselves. As far 
 as such experiments have hitherto gone, they favour the view 
 that the nerves of sense are susceptible of no other kind of sen- 
 sation than that peculiar to each, and are not endowed with 
 the faculty of common sensibility. 
 
 Among the well-attested facts of physiology, again, there is 
 not one to support the belief that one nerve of sense can assume 
 the functions of another. The exaggeration of the sense of 
 touch in the blind will not in these days be called seeing with the 
 fingers ; the accounts of the power of vision by the fingers and 
 epigastrium, said to be possessed in the so-called magnetic 
 state, appear to be mere fables, and the instances in which it has 
 been pretended to practise it, cases of deception. The nerves of 
 touch are capable of no other sensation than that of touch or 
 feeling. Hence, also, no sounds can be heard except by the 
 auditory nerve; the vibrations of bodies are perceived by the 
 nerves of touch as mere tremours wholly different in its nature 
 from sound; though it is indeed even now not rare for the differ- 
 ent modes of action of the vibrations of bodies upon the sense 
 of hearing, and upon that of feeling, to be confounded. With- 
 out the organ of hearing with its vital endowments, there would 
 be no such a thing as sound in the world, but merely vibrations; 
 without the organ of sight, there would be no light, colour, nor 
 darkness, but merely a corresponding presence or absence of 
 the oscillations of the imponderable matter of light. 
 
 VII. // is not known whether the essential cause of tlie peculiar 
 "energy " of each neme of sense is seated in the nerve itself, or in the 
 parts of the brain and spinal cord with which it is connected; but it 
 is certain that the central portions of the nerves included in the 
 encephalon are susceptible of their peculiar sensations, inde- 
 pendently of the more peripheral portion of the nervous cords 
 which form the means of communication with the external organs 
 of sense.
 
 ELEMENTS OF PSYCHOLOGY 543 
 
 The specific sensibility of the individual senses to particular 
 stimuli, owing to which vibrations of such rapidity or length 
 as to produce sound are perceived, only by the senses of hearing 
 and touch, and mere mechanical influences, scarcely at all by 
 the sense of taste, must be a property of the nerves them- 
 selves; but the peculiar mode of reaction of each sense, after the 
 excitement of its nerve, may be due to either of two conditions. 
 Either the nerves themselves may communicate impressions 
 different in quality to the sensorium, which in every instance 
 remains the same; or the vibrations of the nervous principle 
 may in every nerve be the same and yet give rise to the percep- 
 tion of different sensations in the sensorium, owing to the parts 
 of the latter with which the nerves are connected having differ- 
 ent properties. 
 
 The proof of either of these propositions I regard as at 
 present impossible. . . . 
 
 VIII. The immediate objects of the perception of our senses are 
 merely particular states induced in the nerves, and felt as sensa- 
 tions either by the nerves themselves or by the sensorium; but inas- 
 much as the nerves of the senses are material bodies, and therefore 
 participate in the properties of matter generally occupying space, 
 being susceptible of vibratory motion, and capable of being changed 
 chemically as well as by the action of heat and electricity, they 
 make known to the sensorium, by virtue of the changes thus produced 
 in them by external causes, not merely their own condition, but also 
 properties and changes of condition of external bodies. The in- 
 formation thus obtained by the senses concerning external nature, 
 -varies in each sense, having a relation to the qualities or energies of 
 the nerve. 
 
 Qualities which are to be regarded rather as sensations or 
 modes of reaction of the nerves of sense, are light, colour, the 
 bitter and sweet tastes, pleasant and unpleasant odours, pain- 
 ful and pleasant impressions on the nerves of touch, cold and 
 warmth: properties which may belong wholly to external na- 
 ture are "extension," progressive and tremulous motion, and 
 chemical change. 
 
 All the senses are not equally adapted to impart the idea of
 
 544 JOHANNES MUELLER 
 
 "extension" to the sensorium. The nerve of vision and the 
 nerve of touch, being capable of an exact perception of this 
 property in themselves, make us acquainted with it in external 
 bodies. In the nerves of taste, the sensation of extension is less 
 distinct, but is not altogether deficient ; thus we are capable of 
 distinguishing whether the seat of a bitter or sweet taste be the 
 tongue, the palate, or the fauces. In the sense of touch and 
 sight, however, the perception of space is most acute. The retina 
 of the optic nerve has a structure especially adapted for this 
 perception; for the ends of the nervous fibres in the retina are, 
 as Treviranus discovered, so arranged as to be at last perpen- 
 dicular to its inner surface, and by their papillar extremities 
 form a pavement-like composite membrane. On the great num- 
 ber of these terminal fibrils depends the delicate power of dis- 
 criminating the position of bodies in space possessed by the 
 sense of vision ; for each fibre represents a greater or less field of 
 the visible world, and imparts the impression of it to the sens- 
 orium. 
 
 The sense of touch has a much more extended sphere of ac- 
 tion for the perception of space than has the sense of vision ; but 
 its perception of this quality of external bodies is much less ac- 
 curate; and considerable portions of the surface of the body or 
 skin are in many instances represented in the sensorium by 
 very few nervous fibres; hence, in many parts of the surface, 
 impressions on two points considerably removed from each 
 other are, as E. H. Weber has shown, felt as one impression. 
 Although the senses of vision, touch, and taste are all capable 
 of perceiving the property of extension in space, yet the quality 
 of the sensations which give the conception of extension is 
 different in each of these senses ; the sensation in one is an image 
 of which the essential quality is light; in another, a perception 
 of extension with any of the modifications of the quality of 
 touch, between pain, cold, heat, and pleasure; in the third, a 
 perception of extension with the quality of taste.
 
 RUDOLF HERMANN LOTZE 
 
 (1817-1881) 
 
 OUTLINES OF PSYCHOLOGY 
 
 CHAPTER IV. THE THEORY OF LOCAL SIGNS 
 
 27. Metaphysic raises the doubt, whether space is actually 
 extended and we, together with 'Things,' are contained in it; 
 whether just the reverse the whole spatial world is not 
 rather only a form of intuition in us. 
 
 This question we for the present leave one side, and in the 
 meantime take our point of departure from the assumption, pre- 
 viously alluded to, with which we are all conversant. But since 
 Things in space can never become the object of our perception 
 by virtue of their bare existence, and, on the contrary, become 
 such solely through the effects which they exercise upon us, the 
 question arises: How do the Things by their influence upon us 
 bring it to pass, that we are compelled mentally to represent 
 them in the same reciprocal position in space, in which they 
 actually exist outside of us? 
 
 28. In the case of the eye, nature has devised a painstaking 
 structure, such that the rays of light which come from a lumin- 
 ous point are collected again at one point on the retina, and 
 that the different points of the image, which originate here, as- 
 sume the same reciprocal relation toward one another as the 
 
 * From H. Lotze's Grundzilge der Psychologic : Dictate aus den Vorlesungen. 
 Lpz. 1881; 3 Aufl. 1884. Reprinted from H. Lotze's Outlines of Psychology: 
 Dictated Portions of the Lectures. Translated and edited by George T. Ladd. 
 Boston: Ginn & Co. 1886.
 
 546 RUDOLPH HERMANN LOTZE 
 
 points of the object outside of us, to which they correspond. 
 Without doubt, this so-called 'image of the object,' so care- 
 fully prepared, is an indispensable condition of our being able 
 mentally to present the object in its true form and position. 
 But it is the source of all the errors in this matter to believe 
 that the bare existence of this image, without anything else, 
 explains our idea of the position of its parts. The entire image 
 is essentially nothing but a representative of the external ob- 
 ject, transposed into the interior of the organ of sense; and how 
 we know and experience aught of it, is now just as much the 
 question as the question previously was, How can we per- 
 ceive the external object? 
 
 29. If one wished to conceive of the soul itself as an ex- 
 tended being, then the impressions on the retina would, of 
 course, be able to transplant themselves, with all their geo- 
 metrical regularity, to the soul. One point of the soul would be 
 excited as green, the other red, a third yellow; and these three 
 would lie at the corners of a triangle precisely in the same way 
 as the three corresponding excitations on the retina. 
 
 It is also obvious, however, that there is no real gain in all 
 this. The bare fact that three different points of the soul are 
 excited is, primarily, a disconnected three-fold fact. A know- 
 ledge thereof, however, and therefore a knowledge of this three- 
 foldness, and of the reciprocal positions of the three points, is, 
 nevertheless, by no means given in this way: but such know- 
 ledge could be brought about only by means of a uniting and 
 relating activity; and this itself, like every activity, would be 
 perfectly foreign to all predicates of extension and magnitudes 
 in space. 
 
 30. The same thought is more immediately obvious if we 
 surrender this useless notion of the soul being extended, and 
 consider it as a supersensible essence, which, in case we wish to 
 bring it at all into connection with spatial determinations, 
 could be represented only as an indivisible point. 
 
 On making the transition into this indivisible point, the
 
 OUTLINES OF PSYCHOLOGY 547 
 
 manifold impressions must obviously lose all the geometrical 
 relations which they might still have upon the extended retina, 
 - just in the same way as the rays of light, which converge at 
 the single focus of a lens, are not side by side with one another, 
 but only all together, in this point. Beyond the focus, the rays 
 diverge in the same order as that in which they entered it. No- 
 thing analogous to this, however, happens in our consciousness; 
 that is to say, the many impressions, which were previously 
 side by side with one another, do not actually again separate 
 from each other; but, instead of this, the aforesaid activity of 
 mental presentation simply occurs, and it transposes their 
 images to different places in the space that is only 'intuited' 
 by it. 
 
 Here, too, the previous observation holds good : The mental 
 presentation is not that which it presents; and the idea of a 
 point on the left does not lie on the left of the idea of a point on 
 the right; but of one mental presentation, which in itself has no 
 spatial properties whatever, both points are merely themselves 
 so presented before the mind, as though one lay to the left, the 
 other to the right. 
 
 31. The following result now stands before us: Many im- 
 pressions exist conjointly in the soul, although not spatially 
 side by side with one another; but they are merely together in 
 the same way as the synchronous tones of a chord; that is to 
 say, qualitatively different, but not side by side with, above 
 or below, one another. Notwithstanding, the mental presenta- 
 tion of a spatial order must be produced again from these 
 impressions. The question is, therefore, in the first place, to be 
 raised : How in general does the soul come to apprehend these 
 impressions, not in the form in which they actually are, to 
 wit, non-spatial, but as they are not, in a spatial juxta- 
 position? 
 
 The satisfactory reason obviously cannot lie in the impres- 
 sions themselves, but must lie solely in the nature of the soul in 
 which they appear, and upon which they themselves act sim- 
 ply as stimuli.
 
 548 RUDOLPH HERMANN LOTZE 
 
 On this account, it is customary to ascribe to the soul this 
 tendency to form an intuition of space, as an originally inborn 
 capacity. And indeed we are compelled to rest satisfied with 
 this. All the 'deductions' of space, hitherto attempted, which 
 have tried to show on what ground it is necessary to the nature 
 of the soul to develop this intuition of space, have utterly 
 failed of success. Nor is there any reason to complain over this 
 matter; for the simplest modes of the experience of the soul 
 must always merely be recognized as given facts, just as, for 
 example, no one seriously asks why we only hear, and do not 
 rather taste, the waves of air. 
 
 32. The second question is much more important. Let it 
 be assumed that the soul once for all lies under the necessity of 
 mentally presenting a certain manifold as in juxtaposition in 
 space; How does it come to localize every individual impression 
 at a definite place in the space intuited by it, in such manner 
 that the entire image thus intuited is similar to the external 
 object which acted on the eye? 
 
 Obviously, such a clue must lie in the impressions them- 
 selves. The simple quality of the sensation ' green ' or ' red ' does 
 not, however, contain it; for every such color can in turn ap- 
 pear at every point in space, and on this account does not, of 
 itself, require always to be referred to the one definite point. 
 
 We now remind ourselves, however, that the carefulness with 
 which the regular position on the retina of the particular excita- 
 tions is secured, cannot be without a purpose. To be sure, an 
 impression is not seen at a definite point on account of its being 
 situated at such point; but it may perhaps by means of this 
 definite situation act on the soul otherwise than if it were else- 
 where situated. 
 
 Accordingly we conceive of this in the following way: Every 
 impression of color r for example, red produces on all 
 places of the retina, which it reaches, the same sensation of red- 
 ness. In addition to this, however, it produces on each of these 
 different places, a, b, c, a certain accessory impression, a, y3, 7, 
 which is independent of the nature of the color seen, and de-
 
 OUTLINES OF PSYCHOLOGY 549 
 
 pendent merely on the nature of the place excited. This second 
 local impression would therefore be associated with every im- 
 pression of color r, in such manner that ra signifies a red that 
 acts on the point a, r/3 signifies the same red in case it acts on the 
 point b. These associated accessory impressions would, accord- 
 ingly, render for the soul the clue, by following which it trans- 
 poses the same red, now to one, now to another spot, or simul- 
 taneously to different spots in the space intuited by it. 
 
 In order, however, that this may take place in a methodical 
 way, these accessory impressions must be completely different 
 from the main impressions, the colors, and must not disturb 
 the latter. They must be, however, not merely of the same 
 kind among themselves, but wholly definite members of a 
 series or a system of series; so that for every impression r 
 there may be assigned, by the aid of this adjoined 'local sign,' 
 not merely a particular, but a quite definite spot among all the 
 rest of the impressions. 
 
 33. The foregoing is the theory of 'Local Signs.' Their 
 fundamental thought consists in this, that all spatial differ- 
 ences and relations among the impressions on the retina must 
 be compensated for by corresponding non-spatial and merely 
 intensive relations among the impressions which exist together 
 without space-form in the soul ; and that from them in reverse 
 order there must arise, not a new actual arrangement of these 
 impressions in extension, but only the mental presentation of 
 such an arrangement in us. To such an extent do we hold this 
 principle to be a necessary one. 
 
 On the contrary, only hypotheses are possible in order to 
 answer the question, In what do those accessory impressions 
 requisite consist, so far as the sense of sight is concerned? We 
 propose the following conjecture: 
 
 In case a bright light falls upon a lateral part of the retina, 
 on which as is well known the sensitiveness to impressions 
 is more obtuse than in the middle of the retina, then there fol- 
 lows a rotation of the eye until the most sensitive middle part 
 of the retina, as the receptive organ, is brought beneath this
 
 550 RUDOLPH HERMANN LOTZE 
 
 light: we are accustomed to style this the "fixation of vision" 
 upon the aforesaid light. Such motion happens involuntarily, 
 without any original cognition of its purpose, and uniformly 
 without cognition of the means by which it is brought about. 
 We may therefore reckon it among the so-called reflex motions, 
 which originate by means of an excitation of one nerve, that 
 serves at other times for sensation, being transplanted to motor 
 nerves without any further assistance from the soul and in ac- 
 cordance with the pre-existing anatomical connections; and 
 these latter nerves being therefore stimulated to execute a 
 definite motion in a perfectly mechanical way. Now in order to 
 execute such a rotation of the eye as serves the purpose previ- 
 ously alluded to, every single spot in the retina, in case it is 
 stimulated, must occasion a magnitude and direction of the 
 aforesaid rotation peculiar to it alone. But at the same time all 
 these rotations of the eye would be perfectly comparable mo- 
 tions, and, of course, members of a system of series that are 
 graded according to magnitude and direction. 
 
 34. The application of the foregoing hypothesis (many 
 more minute particular questions being disregarded) we con- 
 ceive of as follows: In case a bright light falls upon a lateral 
 point P of a retina, which has not yet had any sensation of light 
 whatever, then there arises, in consequence of the connection in 
 the excitation of the nerves, such a rotation of the eye as that, 
 instead of the place P, the place E of clearest vision is brought 
 beneath the approaching stimulus of the light. Now while the 
 eye is passing through the arc PE, the soul receives at each 
 instant a feeling of its momentary position, a feeling of the 
 same kind as that by which we are, when in the dark, informed 
 of the position of our limbs. To the arc PE there corresponds 
 then a series of constantly changing feelings of position, the 
 first member of which we call TT, and the last of which we 
 call e. 
 
 If now, in a second instance, the place P is again stimulated 
 by the light, then there originates not simply the rotation PE 
 for a second time, but the initial member of the series of feeling
 
 OUTLINES OF PSYCHOLOGY 551 
 
 of position TT, reproduces in memory the entire series associated 
 with it, ire ; and this series of mental presentations is independ- 
 ent of the fact that at the same time also the rotation of the eye 
 PE actually follows. 
 
 Exactly the same thing would hold good of another point R; 
 only the arc RE, the series of feelings pe, and also the initial 
 member of the series, p, would have other values. 
 
 Now finally, in case it came about that both places, P and R, 
 were simultaneously stimulated with an equal intensity, and 
 that the arcs PE and RE were equal but in opposite directions 
 to each other, then the actual rotation of the eye PE and RE 
 could not take place; on the other hand, the excitation upon 
 the places P and R is nevertheless not without effect ; each pro- 
 duces the series of feelings of position belonging to it, re- 
 spectively, 7T and pe. Although therefore the eye does not now 
 move, yet there is connected with every excitation of the places 
 P and R the mental presentation of the magnitude and of the 
 qualitative peculiarity of a series of changes, which conscious- 
 ness or the common feeling would have to experience, in order 
 that these excitations may fall upon the place of clearest 
 vision, or, according to the customary expression, in the line of 
 vision. 
 
 And now we assert that to see anything ' to the right ' or ' to 
 the left ' of this line of vision means nothing more than this, to 
 be conscious of the magnitude of the achievement which would 
 be necessary to bring the object into this line. 
 
 35- By the foregoing considerations nothing further would 
 be established than the relative position of the single colored 
 points in the field of vision. The entire image, on the contrary, 
 would still have no place at all in a yet larger space; indeed, 
 even the mental presentation of such a place would as yet have 
 no existence. 
 
 Now this image first attains a place with reference to the eye, 
 the repeated opening and closing of which, since it can become 
 known to us in another way, is the condition of its existence or 
 non-existence. That is to say, the visible world is in front before
 
 552 RUDOLPH HERMANN LOTZE 
 
 our eyes. What is behind us not merely has no existence what- 
 ever for us, but we do not once know that there is anything 
 which should be called 'behind.' 
 
 The motions of the body lead us further. If the field of vision 
 in a position of rest contains from left to right the images a be, 
 and we then turn ourselves to the right upon our axis, a van- 
 ishes, but d appears on the right, and therefore the image 
 bed, cde, def, . . . xyz, yza, zab, abc, succeed in order. As a 
 result of such recurrence of the images with which we began, 
 the two following thoughts originate; namely, that the visible 
 world of objects exists in a closed circuit of extension about us, 
 and that the alteration of our own position, which we perceive 
 by means of the changing feelings of position while turning, 
 depends upon an alteration of our relation to this immovable 
 world of objects, that is to say, upon a motion. 
 
 It is easily understood that the mental picture of a spherical 
 extension originates from the aforesaid mental picture of a 
 closed horizon by means of repeatedly turning in a similar way 
 in various other directions. 
 
 36. But, nevertheless, this spherical surface also would 
 always have only a superficial extension no intimation would 
 as yet exist of a depth to space. 
 
 Now the mental presentation, to the effect that something 
 like a third dimension of space in general exists, cannot origin- 
 ate of itself, but only through the experience which we have in 
 case we move about among the visible objects. From the mani- 
 fold displacements which the particular visual images experi- 
 ence, in a manner that is tedious to describe but very easy to 
 imagine, we gain the impression, that each line in an image 
 originally seen is the beginning of new surfaces which do not 
 coincide with that previously seen, but which lead out into this 
 space, now extended on all sides, to greater or less distances 
 from the line. 
 
 Another question to be treated subsequently is this: By what 
 means do we estimate the different magnitudes of the distance 
 into this depth of space?
 
 OUTLINES OF PSYCHOLOGY 553 
 
 37. The crossing of the rays of light in the narrow opening 
 of the pupil is the cause of the image of the upper points of the 
 object being formed beneath, that of the lower points above on 
 the retina; and of the whole picture having therefore a position 
 the reverse of the object. But it is a prejudice on this account 
 to consider seeing in inverse position to be natural, and seeing 
 in upright position to be mysterious. Like every geometrical 
 property of the image, so this one of its position, too, on passing 
 into consciousness, is completely lost; and the position in which 
 we see things is in no way prejudiced by the aforesaid position 
 of the image on the retina. 
 
 Now, however, in order that we may be able to ascribe to 
 objects a position at all, in order therefore that the expressions 
 'above,' 'below,' 'upright,' and 'inverted,' may have a mean- 
 ing, we must have, independent of all sensation by sight, a men- 
 tal picture of a space in which the entire content of the field of 
 vision shall be arranged, and in which 'above' and 'below' are 
 two qualitatively opposite and, on this account, not exchange- 
 able directions. 
 
 The muscular feeling affords us such a mental presentation. 
 'Below' is the place toward which the direction of gravity 
 moves; ' above,' the opposite. Both directions are distinguished 
 perfectly for us by means of an immediate feeling; and, on this 
 account, we are never deceived even in the dark about the posi- 
 tion and situation of our body. 
 
 Accordingly we see objects 'upright' in case the lower points 
 of the object are reached by one and the same movement of the 
 eyes simultaneously with those points of our own body which 
 are 'below' according to the testimony of the aforesaid muscu- 
 lar feeling; and the upper points by a movement which, accord- 
 ing to the same testimony, renders visible simultaneously the 
 upper parts of our own selves. 
 
 Now it is exactly such agreement that is secured in our eye, in 
 which the axis lies in front of the sensitive retina, by means of 
 the inverted position of the retinal image. In an other eye in 
 which the sensitive surface should be placed in front of the axis, 
 and yet the greatest sensitiveness also should appear in the
 
 554 RUDOLPH HERMANN LOTZE 
 
 middle portion of that surface, the retinal image would have to 
 stand upright to serve the same purpose. 
 
 38. The final and valid answer to the question, why we 
 have single vision with two eyes, is not to be given. As is well 
 known, it does not always happen. The rather must two im- 
 pressions fall on two quite definite points of the retina in order 
 to coalesce. We see double, on the contrary, if they fall on 
 other points. Naturally, we shall say: The two places which 
 belong together would have to impart like local signs to their 
 impressions, and thereby render them indistinguishable; but we 
 are not able to demonstrate in what manner this postulate is 
 fulfilled. Physiology, too, in the last analysis, satisfies itself 
 with a mere term for the fact; it calls 'identical' those places in 
 both retinas which give one simple impression, and 'non- 
 identical' those which give a double impression. 
 
 39. Irritations of the skin we naturally refer at once to the 
 place of the skin on which we see them acting. But in case of 
 their repetition, when we are not able to see them, we have no 
 assistance from remembering them; for the most ordinary 
 stimuli have already in the course of our life touched all pos- 
 sible places of the skin, and could therefore now as well be re- 
 ferred to one place as to another. In order that they may be 
 correctly localized, they would have at every instant to tell us 
 anew where they belong; that is to say, there must be attached 
 to the main impression (impact, pressure, heat or cold) an 
 auxiliary impression which is independent of the latter and, on 
 the contrary, dependent on the place of the skin that is 
 irritated. 
 
 The skin can supply such local signs; for since it is connected 
 without interruption, a single point of it cannot be irritated at 
 all, without the surrounding portion experiencing a displacement, 
 pulling, stretching, or concussion of some kind. But, further, 
 since the skin possesses at different places a different thickness, 
 different tension or liability to displacement, extends some- 
 times above the firm surfaces of the bones, sometimes over the
 
 OUTLINES OF PSYCHOLOGY 555 
 
 flesh of the muscles, sometimes over cavities; since, moreover, 
 the members being manifold, these relations change from one 
 stretch of skin to another; therefore the aforesaid sum of sec- 
 ondary effects around the point irritated will be different for 
 each one from the remainder; and such effects, if they are taken 
 up by the nerve-endings and act on consciousness, may occa- 
 sion the feelings so difficult to describe, according to which we 
 distinguish a contact at one place from the same contact at 
 another. 
 
 It cannot be said, however, that each point of the skin has its 
 special local sign. It is known from the investigations of E. H. 
 Weber, that on the margin of the lips, the tip of the tongue, the 
 tips of the fingers, being touched in two places (by the points of 
 a pair of compasses) can be distinguished as two at an interval 
 of only \ line ; while there are places on the arms, legs, and on 
 the back, which require for making the distinction a distance 
 between them of as much as 20 lines. We interpret this in the 
 following way. Where the structure of the skin changes little 
 for long stretches, the local signs also alter only a little from 
 point to point. And if two stimuli act simultaneously, and 
 accordingly a reciprocal disturbance of these secondary effects 
 occurs, they will be undistinguishable ; on the contrary, in cases 
 where both stimuli act successively, and therefore the aforesaid 
 disturbance ceases, both are still frequently distinguishable. 
 On the other hand, we know nothing further to allege as to how 
 the extraordinary sensitiveness for example of the lips is 
 occasioned. 
 
 40. The preceding statement merely explains the possibil- 
 ity of distinguishing impressions made at different places; but 
 each impression must also be referred to the definite place at 
 which it acts. 
 
 This is easy for one who sees, since he already possesses a pic- 
 ture of the surface of his own body; and, on this account, he 
 now by means of the unchanging local sign, even in the dark, 
 translates each stimulus which he has once seen act on a definite 
 place, to the same place in this picture of the body that is men-
 
 r 556 RUDOLPH HERMANN LOTZE 
 
 tally presented before him. One born blind would be com- 
 pelled to construct such a picture first by means of the sense of 
 touch; and this naturally is accomplished through motions of 
 the tactual members and by estimating the distances which 
 they would have to travel in order to reach from contact at the 
 point a to contact at the other point b. It is to be considered, 
 however that these motions which in this case are not seen 
 are perceivable only by so-called muscular feelings; that is 
 to say by feelings which in themselves are merely certain 
 species of the way we feel, and do not of themselves at all 
 indicate the motions which are in fact the causes of them. 
 
 Now it cannot be described, how it is that this interpretation 
 of the muscular feelings actually originates In the case of those 
 born blind; but the helps which lead to it are very probably 
 found in the fact, that the sense of touch as well as the eye can 
 receive many impressions simultaneously, and that, in case of a 
 movement, the previous impression does not vanish without 
 trace and have its place taken by a wholly new one; but that, in 
 the manner previously alleged, the combinations abc, bed, etc., 
 follow one another, and therefore some part in common is 
 always left over for the next two impressions. By this alone 
 does it seem possible to awaken the idea that the same occur- 
 rence, from which the series of changeable muscular feelings 
 originates for us, consists in an alteration of our relation to a 
 series of objects previously existent side by side and to be found 
 arranged in a definite order; it consists, therefore, in a motion. 
 
 5 41. It is questionable whether the mental picture of space 
 which one born blind attains solely by the sense of touch will be 
 altogether like that of one who sees; it is rather to be assumed 
 that a much less intuitable system of mental presentations of 
 time, of the magnitude of motion, and of the exertion which is 
 needed in order to reach from contact at one point to that at 
 another, takes the place of the clear, easy, and at once all-com- 
 prehending intuition, with which he who sees is endowed.
 
 ERNST HEINRIGH WEBER 
 
 (1795-1878) 
 
 THE SENSE OF TOUCH AND THE 
 COMMON FEELING 
 
 WEBER'S 
 
 CONCERNING THE SMALLEST PERCEPTIBLE DIFFERENCES OF 
 WEIGHTS WHICH WE CAN DISTINGUISH BY THE SENSE OF 
 TOUCH, OF THE LENGTH OF LINES WHICH WE CAN DISTIN- 
 GUISH BY SIGHT, AND OF TONES WHICH WE CAN DISTINGUISH 
 BY HEARING 
 
 THE smallest perceptible difference between two weights, 
 which we can distinguish by the feeling of muscular exertion, 
 appears according to my experiments to be that between 
 weights which stand approximately in the relation of 39 to 40: 
 that is to say, of which one is about 1-40 heavier than the 
 other. By means of the feeling of pressure, which two weights 
 make upon our skin, all we are able to distinguish is a differ- 
 ence of weight that amounts to only 1-30, so that the weights 
 accordingly stand in the relation of 29 to 30. 
 
 * From Der Taslsinn und das GemeingefUhl in R. Wagner's Handworlerbuch 
 der Physiologic, Braunschweig, 1846, iii, 2; [separately,] Leipzig, 1849; ib., 1851; 
 ib., 1905. 
 
 t The first formulation of what is known as Weber's Law was made by Weber 
 in 1834 in a monograph entitled De tactu. It reads as follows: 
 
 " In comparing objects and observing the distinction between them, we per- 
 ceive not the difference between the objects, but the ratio of this difference to the 
 magnitude of the objects compared. If we are comparing by touch two weights, 
 the one of 30 and the ether of 29 half-ounces, the difference is not more easily 
 perceived than that between weights of 30 and 29 drachms. . . . Since the dis-
 
 558 ERNST HEINRICH WEBER 
 
 If we look at one line after another, any one who possesses a 
 very exceptional visual discrimination can according to my 
 experiments discover a difference between two lines whose 
 lengths are related as 50 : 51, or even as 100 : 101. Those who 
 have a less delicate visual discrimination distinguish lines, 
 which are separated from one another by 1-25 of their length. 
 The smallest perceptible difference of the pitch of two tones, 
 (which are really in unison), that a musician perceives, if he 
 hears two tones successively, is according to Delezenne 1 1-4 
 Komma (81-80) 1-4. A lover of music according to him distin- 
 guishes only about 1-2 Komma (81-80) 1-2. If the tones are 
 heard simultaneously we cannot, according to Delezenne's 
 experiments, perceive such small tonal differences. 1-4 Komma 
 is nearly the relation of 321 1322, but 1-2 Komma is nearly the 
 relation of 160:161. 
 
 tinction is not perceived more easily in the former case than in the latter, it is 
 clear that not the weights of the differences but their ratios are perceived. . . . 
 Experience has taught us that apt and practised o's sense the difference be- 
 tween weights, if it is not less than the thirtieth part of the heavier weight, and 
 that the same o's perceive the difference not less easily, if drachms are put in the 
 place of half-ounces. 
 
 " That which I have set forth with regard to weights compared by touch holds 
 also of lines to be compared by sight. For, whether you compare longer or shorter 
 lines, you will find that the difference is not sensed by most o's if the second line 
 is less by a hundredth part. . . . The length in which the distinction resides, 
 therefore, although [in the case of lines of 50 and 50.5 mm.] it is twice as small 
 [as it is in the case of lines of 100 and 101 mm.], is nevertheless no less easily 
 apprehended, for the reason that in both cases the difference of the compared 
 lines is one hundredth of the longer line. 
 
 " I have made no experiments upon comparison of tones by the ear. [Dele- 
 zenne, however, determined the j. n. d. of the b of 240 vs.] As this author does 
 not say that this difference is discriminated less easily in deeper, more easily in 
 higher tones, and as I have never heard that a difference is more easily perceived 
 in higher tones, ... I imagine that in audition also not the absolute difference 
 between the vibrations of two tones, but the relative compared with the number 
 of vibrations of the tones is discriminated. 
 
 " The observation, confirmed in several departments of sense, that in ob- 
 serving the distinction between objects we perceive not the absolute but the rela- 
 tive differences, has again and again impelled me to investigate the cause of this 
 phenomenon; and I hope that when this cause is sufficiently understood, we shall 
 be able to judge more correctly regarding the nature of the senses " (172 ff.). 
 Translation in E. B. Titchener's Experimental Psychology, ii, part ii, p. xvi. 
 
 1 Delezenne in Recueil des Travaux de la sac. des sci. de Lille, 1827.
 
 THE SENSE OF TOUCH 559 
 
 I have shown that the result in the determinations of weight 
 is the same, whether one takes ounces or half ounces; for it 
 does not depend upon the number of grains that form the 
 increment of weight, but depends on the fact that this incre- 
 ment makes up the thirtieth or fiftieth [should be fortieth] part 
 of the weight which we are comparing with the second weight. 
 This likewise holds true of the comparison of the length of two 
 lines and of the pitch of two tones. It makes no difference 
 whether we compare lines that are, say, two inches or one inch 
 long, if we examine them successively, and can see them lying 
 parallel to each other; and yet the extent by which the one line 
 exceeds the other is in the former case twice as great as in the 
 latter. To be sure, if both lines lie close together and parallel, 
 we compare only the ends of the lines to discover how much 
 the one line exceeds the other; and in this test the question is 
 only how great that length of line which overlaps the other 
 really is, and how near the two lines lie to one another. 
 
 So too in the comparison of the pitch of two tones, it does 
 not matter whether the two tones are seven tonal stops [i.e. an 
 octave] higher or lower, provided only they do not lie at the end 
 of the tonal series, where the exact discrimination of small 
 tonal differences becomes more difficult. Here again, therefore, 
 it is not a question of the number of vibrations, by which the 
 one tone exceeds the other, but of the relation of the numbers of 
 the vibrations of the two tones which we are comparing. If we 
 counted the vibrations of the two tones it would be conceivable, 
 that we should pay attention only to the number of vibrations 
 by which one tone exceeds the other. If we fix the eyes first 
 upon one line and afterwards upon a second, and thus permit 
 both to be pictured successively upon the most sensitive parts 
 of the retina, we should be inclined to suppose, that we com- 
 pared the traces of the impression which the first image left, 
 with the impression which the second image made upon the 
 same parts of the retina, and that we thereby perceived how 
 much the second image exceeds the first, and conversely. For 
 this is the way we compare two scale-units: we place one upon 
 the other, so that they coincide, and thus perceive how much
 
 560 ERNST HEINRICH WEBER 
 
 the one exceeds the other. From the fact, that we do not em- 
 ploy this method which is so very advantageous, it seems to 
 follow, that we are unable to employ it, and that therefore the 
 preceding impression left behind no such trace upon the retina, 
 or in the brain, as would permit of comparison in the manner 
 mentioned with succeeding impressions. That it is possible 
 for us to proceed otherwise in the comparison of the length of 
 two lines appears from the fact, that we can compare two lines, 
 which are longer than we can picture at once in their en- 
 tirety on the most sensitive part of the retina. In this case we 
 must move the eye and thereby cause the different parts of the 
 same line to be pictured successively upon the same parts of the 
 retina. Under these circumstances we must take account of 
 the movement of the eye, and only thus do we form an idea of 
 the length of the lines. Were the impressions of visible things, 
 which we preserve in memory, traces, which the sensuous 
 impressions left behind in the brain, and whose spatial relations 
 corresponded to the spatial relations of the sensuous impres- 
 sions, and were thus so to speak photographs of the same, it 
 would be difficult to remember a figure, which is larger than 
 could be pictured at once wholly upon the sensitive part of the 
 retina. It appears to me, indeed, as if a figure, which we can 
 survey at a single glance, impressed itself better upon our 
 memory and our imagination, than a figure, which we can 
 survey only successively by moving the eyes; but we can never- 
 theless represent also the former by means of the imagination. 
 But in this case the representation of the whole figure seems to 
 be composed by us of the parts which we perceive all at once. 
 If we compare two lines, which are 20 and 21 Linien [i.e. i-io 
 of an inch] long, the latter is 1-20 longer, but the absolute dif- 
 ference of length amounts to i Linie. If, on the other hand, we 
 compare two lines, which are i Linie and 1.05 Linie long, 
 the difference amounts also to 1-20, but the line is only 1-20 
 longer than the other. Consequently in the latter case the abso- 
 lute difference is 20 times smaller. But 1-20 Linie is a size like 
 a fine pinhole which lies at the very threshold of vision. The 
 smallest possible point that we are able to see, is one whose di-
 
 THE SENSE OF TOUCH 561 
 
 ameter amounts to 1-20 Lime, and yet one who has a very 
 good visual discrimination can distinguish in respect to their 
 length two lines of which one is 1-20 Linie longer than the other. 
 Two observers, before whom I placed such lines, both distin- 
 guished the longer from the shorter, and their visual discrimi- 
 nation extended even farther. I myself distinguished two lines, 
 whose relative difference of length amounted to 1-20, and of 
 which the one was between 1-17 and 1-18 longer than the 
 other. The apprehension of the relations of whole magnitudes, 
 without our having measured the magnitudes by a smaller 
 scale-unit, and without our having ascertained the absolute dif- 
 ference between them, is a most interesting psychological phe- 
 nomenon. In music we apprehend the relations of tone, without 
 knowing their rate of vibration [i.e., their absolute pitch] ; in 
 architecture, the relation of spatial magnitudes, without hav- 
 ing determined them by inches; and in the same way we ap- 
 prehend the magnitudes of sensation or of force in the com- 
 parison of weights.
 
 GUSTAV THEODOR FEGHNER 
 
 (1801-1887) 
 
 ELEMENTS OF PSYCHOPHYSICS 
 
 Translated from the German * by 
 HERBERT SIDNEY LANGFELD 
 
 VII. THE MEASUREMENT OF SENSATION 
 
 WEBER'S law, that equal relative increments of stimuli are 
 proportional to equal increments of sensation, is, in considera- 
 tion of its generality and the wide limits within which it is abso- 
 lutely or approximately valid, to be considered fundamental 
 for psychic measurement. There are, however, limits to its 
 validity as well as complications, which we shall have carefully 
 to examine later. Yet even where this law ceases to be valid or 
 absolute, the principle of psychic measurement continues' to 
 hold, inasmuch as any other relation between constant incre- 
 ments of sensation and variable increments of stimulus, even 
 though it is arrived at empirically and expressed by an empir- 
 ical formula, may serve equally well as the fundamental basis for 
 psychic measurement, and indeed must serve as such in those 
 parts of the stimulus scale where Weber's law loses its validity. 
 In fact such a law, as well as Weber's law, will furnish a differ- 
 ential formula from which may be derived an integral formula 
 containing an expression for the measurement of sensation. 
 
 This is a fundamental point of view, in which Weber's law, 
 with its limitations, appears, not as limiting the application of 
 psychic measurement, but as restricted in its own application 
 toward that end and beyond which application the general 
 
 * From G. F. Fechner's Elcmenle dcr Psychophysik, Leipzig, 1860; unverand. 
 Aufl. 1889.
 
 ELEMENTS OF PSYCHOPHYSICS 563 
 
 principle of psychic measurement nevertheless continues to hold. 
 It is not that the principle depends for its validity upon 
 Weber's law, but merely that the application of the law is 
 involved in the principle. 
 
 Accordingly investigation in the interest of the greatest 
 possible generalization of psychic measurement has not essen- 
 tially to commence with the greatest possible generalization of 
 Weber's law, which might easily produce the questionable in- 
 clination to generalize the law beyond its natural limitation, or 
 which might call forth the objection that the law was general- 
 ized beyond these limits solely in the interest of psychic meas- 
 urement; but rather it may quite freely be asked how far 
 Weber's law is applicable, and how far not; for the three 
 methods which are used in psychic measurement are applicable 
 even when Weber's law is not, and where these methods are 
 applicable psychic measurement is possible. 
 
 In short, Weber's law forms merely the basis for the most 
 numerous and important applications of psychic measurement, 
 but not the universal and essential one. The most general 
 and more fundamental basis for psychic measurement is rather 
 those methods by which the relation between stimulus incre- 
 ments and sensation increment in general is determined, 
 within, as well as without, the limits of Weber's law; and the 
 development of these methods towards ever greater precision 
 and perfection is the most important consideration in regard 
 to psychic measurement. 
 
 And yet a great advantage would be lost, if so simple a law as 
 Weber's law could not be used as an exact or at least suffi- 
 ciently approximate basis for psychic measurement; just such 
 an advantage as would be lost if we could not use the Kepler 
 law in astronomy, or the laws of simple refraction in the theory 
 of the dioptric instruments. Now there is just the same diffi- 
 culty with these laws as with Weber's law. In the case of 
 Kepler's law we abstract from deviations. In the case of simple 
 lens refraction we abstract from optical aberration. In fact 
 they may become invalid as soon as the simple hypotheses for 
 which they are true no longer exist. Yet they will always re-
 
 564 GUSTAV THEODOR FECHNER 
 
 main decisive for the principle relation with which astronomy 
 and dioptrics are concerned. Weber's law may in like manner, 
 entirely lose its validity, as soon as the average or normal condi- 
 tions under which the stimulus produces the sensation are un- 
 realized. It will always, however, be decisive for these particu- 
 lar conditions. 
 
 Further, just as in physics and astronomy, so can we also 
 in psychic measurement, neglect at first the irregularities and 
 small departures from the law in order to discover and examine 
 the principle relations with which the science has to do. The 
 existence of these exceptions must not, however, be forgotten, 
 inasmuch as the finer development and further progress of the 
 science depends upon the determination and calculation of 
 them, as soon as the possibility of doing so is given. 
 
 The determination of psychic measurement is a matter for 
 outer psychophysics and its first applications lie within its 
 boundary; its further applications and consequences, however, 
 extend necessarily into the domain of inner psychophysics and 
 its deeper meaning lies there. It must be remembered that the 
 stimulus does not cause sensation directly, but rather through 
 the assistance of bodily processes with which it stands in more 
 direct connection. The dependence, quantitatively considered 
 of sensation on stimulus, must finally be translated into one of 
 sensation on the bodily processes which directly underlie the 
 sensation in short the psycho-physical processes; and the 
 sensation, instead of being measured by the amount of the 
 stimulus, \\till be measured by the intensity of these processes. 
 In order to do this, the relation of the inner process to the stim- 
 ulus must be known. Inasmuch as this is not a matter of direct 
 experience it must be deduced by some exact method. Indeed 
 it is possible for this entire investigation to proceed along ex- 
 act lines, and it cannot fail at some time or other to obtain 
 the success of a critical study, if one has not already reached 
 that goal. 
 
 Although Weber's law, as applied to the relation of stimulus 
 to sensation, shows only a limited validity in the domain of 
 outer psychophysics, it has, as applied to the relation of sensa-
 
 ELEMENTS OF PSYCHOPHYSICS 565 
 
 tion to kinetic energy, or as referred to some other function of 
 trie psycho-physical process, in all probability an unlimited 
 validity in the domain of inner psychophysics, in that all excep- 
 tions to the law which we find in the arousal of sensation by 
 external stimulus, are probably due to the fact that the stimu- 
 lus only under normal or average conditions engenders a kinetic 
 energy in those inner processes proportional to its own amount. 
 From this it may be foreseen, that this law, after it has been 
 restated as a relation between sensation and the psycho- 
 physical processes, will be as important, general, and funda- 
 mental for the relations of mind to body, as is the law of gravity 
 for the field of planetary motion. And it also has that simplicity 
 which we are accustomed to find in fundamental laws of 
 nature. 
 
 Although, then, psychic measurement depends upon 
 Weber's law only within certain limitations in the domain of 
 outer psycho-physics, it may well get its unconditional support 
 from this law in the field of inner psychophysics. These are 
 nevertheless for the present merely opinions and expectations, 
 the verification of which lies in the future. 
 
 XIV. THE FUNDAMENTAL FORMULA AND THE 
 MEASUREMENT FORMULA 
 
 Although not as yet having a measurement for sensation, still 
 one can combine in an exact formula the relation expressed in 
 Weber's law, that the sensation difference remains constant 
 when the relative stimulus difference remains constant, with 
 the law, established by the mathematical auxiliary principle, 
 that small sensation increments are proportional to stimu- 
 lus increments. Let us suppose, as has generally been done in 
 the attempts to preserve Weber's law, that the difference be- 
 tween two stimuli, or, what is the same, the increase in one 
 stimulus, is very small in proportion to the stimulus itself. Let 
 the stimulus which is increased be called /3, the small increase 
 J/3, where the letter d is to be considered not as a special mag- 
 nitude, but simply as a sign that dfi is the small increment of
 
 $66 GUSTAV THEODOR FECHNER 
 
 ft. This already suggests the differential sign. The relative 
 stimulus increase therefore is -Q. On the other hand, let the 
 
 sensation which is dependent upon the stimulus ft be called 
 7, and let the small increment of the sensation which results 
 from the increase of the stimulus by dft be called dy, where 
 d again simply expresses the small increment. The terms dft 
 and dy are each to be considered as referring to an arbitrary 
 unit of their own nature. 
 According to the empirical Weber's law, dy remains constant 
 
 when -Q remains constant, no matter what absolute values 
 
 dft and ft take; and according to the a priori mathematical 
 auxiliary principle the changes dy and dft remain propor- 
 tional to one another so long as they remain very small. The two 
 relations maybe expressed together in the following equation: 
 
 *-^ 
 
 where K is a constant (dependent upon the units selected for 7 
 and ft) . In fact, if one multiplies ftd and ft by any number, so 
 long as it is the same number for both, the proportion remains 
 constant, and with it also the sensation difference dy. This is 
 Weber's law. If one doubles or triples the value of the variation 
 dft without changing the initial value ft, then the value of the 
 change dy is also doubled or tripled. This is the mathematical 
 
 VJQ 
 
 principle. The equation dyQ- therefore entirely satisfies 
 
 both Weber's law and this principle; and no other equation 
 satisfies both together. This is to be called the fundamental 
 formula, in that the deduction of all consequent formulas will 
 be based upon it. 
 
 The fundamental formula does not presuppose the measure- 
 ment of sensation, nor does it establish any; it simply expresses 
 the relation holding between small relative stimulus incre- 
 ments and sensation increments. In short, it is nothing more 
 than Weber's law and the mathematical auxiliary principle 
 united and expressed in mathematical symbols.
 
 ELEMENTS OF PSYCHOPHYSICS 567 
 
 There is, however, another formula connected with this 
 formula by infinitesimal calculus, which expresses a general 
 quantitative relation between the stimulus magnitude as a 
 summation of stimulus increments, and the sensation magni- 
 tude as a summation of sensation increments, in such a way, 
 that with the validity of the first formula, together with the 
 assumption of the fact of limen, the validity of this latter 
 formula is also given. 
 
 Reserving for the future a more exact deduction, I shall 
 attempt first to make clear in a general way the connection of 
 the two formulas. 
 
 One can readily see, that the relation between the increments 
 dy and dft in the fundamental formula corresponds to the rela- 
 tion between the increments of a logarithm and the increments 
 of the corresponding number. For as one can easily convince 
 oneself, either from theory or from the table, the logarithm 
 does not increase by equal increments when the corresponding 
 number increases by equal increments, but rather when the 
 latter increases by equal relative amounts; in other words, the 
 increases in the logarithms remain equal, when the relative in- 
 creases of the numbers remain equal. Thus, for example, the 
 following numbers and logarithms belong together: 
 
 Number. 
 
 Logarithm. 
 
 10 
 
 I.OOOOOO 
 
 ii 
 
 1.0413927 
 
 100 
 
 2.OOOOOO 
 
 no 
 
 2.0413927 
 
 IOOO 
 
 3.OOOOOO 
 
 IIOO 
 
 3.0413927 
 
 where an increase of the number 10 by i brings with it just as 
 great an increase in the corresponding logarithm, as the increase 
 of the number 100 by 10 or 1000 by 100. In each instance the 
 increase in the logarithm is 0.0413927. Further, as was already 
 shown in explaining the mathematical auxiliary principle, the 
 increases in the logarithms are proportional to the increases of
 
 568 GUSTAV THEODOR FECHNER 
 
 the numbers, so long as they remain very small. Therefore one 
 can say, that Weber's law and the mathematical auxiliary prin- 
 ciple are just as valid for the increases of logarithms and num- 
 bers in their relation to one another, as they are for the increases 
 of sensation and stimulus. 
 
 The fact of the threshold appears just as much in the relation 
 of a logarithm to its number as in the relation of sensation to 
 stimulus. The sensation begins with values above zero, not 
 with zero, but with a finite value of the stimulus the thres- 
 hold ; and so does the logarithm begin with values above zero, 
 not with a zero value of the number, but with a finite value of 
 the number, the value i, inasmuch as the logarithm of i is 
 equal to zero. 
 
 If now, as was shown above, the increase of sensation and 
 stimulus stands in a relation similar to that of the increase of 
 logarithm and number, and, the point at which the sensation 
 begins to assume a noticeable value stands in a relation to the 
 stimulus similar to that which the point at which the logarithm 
 attains positive value stands to the number, then one may 
 also expect that sensation and stimulus themselves stand in a 
 relation to one another similar to that of logarithm to number, 
 which, just as the former (sensation and stimulus) may be 
 regarded as made up of a sum of successive increments. 
 
 Accordingly the simplest relation between the two that we 
 can write is 7 = log ft. 
 
 In fact it will soon be shown that, provided suitable units of 
 sensation and stimulus are chosen, the functional relation 
 between both reduces to this very simple formula. Meanwhile 
 it is not the most general formula that can be derived, but one 
 which is only valid under the supposition of particular units of 
 sensation and stimulus, and we still need a direct and absolute 
 deduction instead of the indirect and approximate one. 
 
 The specialist sees at once how this may be attained, namely, 
 by treating the fundamental formula as a differential formula 
 and integrating it. In the following chapter one will find this 
 done. Here it must be supposed already carried out, and those 
 who are not able to follow the simple infinitesimal deduction,
 
 ELEMENTS OF PSYCHOPHYSICS 569 
 
 must be asked to consider the result as a mathematical fact. 
 This result is the following functional formula between stimu- 
 lus and sensation, which goes by the name of the measurement 
 formula and which will now be further discussed: 
 
 In this formula K again stands for a constant, dependent upon 
 the unit selected and also the logarithmic system, and b a second 
 constant which stands for the threshold value of the stimulus, 
 at which the sensation 7 begins and disappears. 
 
 According to the rule, that the logarithm of a quotient of two 
 numbers may be substituted for the difference of their logar- 
 ithms, . . . one can substitute for the above form of the meas- 
 urement formula the following, which is more convenient for 
 making deductions. ~ 
 
 y = K log | ( 3 ) 
 
 From this equation it follows that the sensation magnitude 7 
 is not to be considered as a simple function of the stimulus 
 value /3, but of its relation to the threshold value b, where the 
 sensation begins and disappears. This relative stimulus value, 
 
 is for the future to be called the fundamental stimulus value, 
 
 or the fundamental value of the stimulus. 
 
 Translated in words, the measurement formula reads: 
 The magnitude of the sensation (7) is not proportional to the 
 absolute value of the stimulus (/3), but rather to the logarithm of 
 the magnitude of the stimulus, when this last is expressed in terms 
 of its threshold value(b), i. e. that magnitude considered as unit 
 at which the sensation begins and disappears. In short, it is pro- 
 portional to the logarithm of the fundamental stimulus value. 
 
 Before we proceed further, let us hasten to show that that 
 relation between stimulus and sensation, from which the meas- 
 urement formula is derived, may be correctly deduced in turn 
 from it, and that this latter thus finds its verification in so far 
 as these relations are found empirically. We have here at the 
 same time the simplest examples of the application of the meas- 
 urement formula.
 
 570 GUSTAV THEODOR FECHNER * 
 
 The measurement formula is founded upon Weber's law and 
 the fact of the stimulus threshold; and both must follow in turn 
 from it. 
 
 Now as to Weber's law. In the form that equal increments of 
 sensation are proportional to relative stimulus increments, it 
 may be obtained by differentiating the measurement formula, 
 inasmuch as in this way one returns to the fundamental for- 
 mula, which contains the expression of the law in this form. 
 
 In the form, that equal sensation differences correspond to 
 equal relations of stimulus, the law may be deduced in quite an 
 elementary manner as follows. 
 
 Let two sensations, whose difference is to be considered, be 
 called 7 and 7', and the corresponding stimuli /3 and ft. Then 
 according to the measurement formula 
 
 y = K (log ft - log 6) 
 
 and likewise for the sensation difference 
 
 or, since log ft - log ft' = log j| 
 
 From this formula it follows, that the sensation difference 7-7' 
 is a function of the stimulus relation -g, , and remains the same 
 
 no matter what values ft, $ may take, so long as the relation 
 remains unchanged, which is the statement of Weber's law. 
 
 In a later chapter we shall return to the above formula under 
 the name of the difference formula, as one of the simplest conse- 
 quences of the measurement formula. 
 
 As for the fact of the threshold, which is caused by the sensa- 
 tion having zero value not at zero but at a finite value of the 
 stimulus, from which point it first begins to obtain notice- 
 able values with increasing values of stimulus, it is so far con- 
 tained in the measurement formula as 7 does not, according 
 to this formula, have the value zero when ft = o, but when /3 
 is equal to a finite value b. This follows as well from equation
 
 ELEMENTS OF PSYCHOPHYSICS 571 
 
 (2) as (3) of the measurement formula, directly from (2), and 
 from (3) with the additional consideration of the fact, that 
 
 13 
 
 when ft equals b, log T equals log i, and log i = o. 
 
 Naturally all deduction from Weber's law and the fact of 
 the threshold will also be deductions from our measurement 
 formula. 
 
 It follows from the former law, that every given increment of 
 stimulus causes an ever decreasing increment in sensation in 
 proportion as the stimulus grows larger, and that at high values 
 of the stimulus it is no longer sensed, while on the other hand, 
 at low values it may appear exceptionally strong. 
 
 In fact the increase of a large number ft by a given amount 
 is accompanied by a considerably smaller increase in the corre- 
 sponding logarithm y, than the increase of a small number /3 by' 
 the same amount.' When the number 10 is increased by 10, 
 (that is, reaches 20), the logarithm corresponding to 10, which 
 is i, is increased to 1.3010. When, however, the number 1000 
 is increased by 10, the logarithm corresponding to 1000, namely 
 3, is only increased to 3.0043. In the first case the logarithm is 
 increased by 1-3 of its amount, in the latter case by about 1-700. 
 
 In connection with the fact of the threshold belongs the de- 
 duction, that a sensation is further from the perception thres- 
 hold the more the stimulus sinks under its threshold value. 
 This distance of a sensation from the threshold, is represented in 
 the same manner by the negative values of y, according to our 
 measurement formula, as the increase above the threshold is 
 represented by the positive values. 
 
 In fact one sees directly from equation (2), that when /3 is 
 smaller than b and with it log /3 smaller than log b, the sensa- 
 tion takes on negative values, and the same deduction follows in 
 
 equation (3), in that r, becomes a proper fraction when @<^b, 
 
 and the logarithm of a proper fraction is negative. 
 
 In so far as sensations, which are caused by a stimulus 
 which is not sufficient to raise them to consciousness, are called 
 unconscious, and those which affect consciousness are called
 
 572 GUSTAV THEODOR FECHNER 
 
 conscious, we may say that the unconscious sensations are 
 represented in our formula by negative, the conscious by posi- 
 tive values. We will return to this statement in a special chap- 
 ter (chapter 18) since it is of great importance, and perhaps not 
 directly evident to everyone. For the present I shall not let it 
 detain me longer. 
 
 According to the foregoing our measurement formula corre- 
 sponds to experience: 
 
 1. In the cases of equality, where a sensation difference 
 remains the same when the absolute intensity of the stimulus is 
 altered (Weber's law). 
 
 2. In the cases of the thresholds, where the sensation itself 
 ceases, and where its change becomes either imperceptible or 
 barely perceptible. In the former case, when the sensation 
 reaches its lower threshold ; in the latter case, when it becomes 
 so great that a given stimulus increase is barely noticed. 
 
 3. In the contrasting cases, between sensations which rise 
 above the threshold of consciousness and those that do not 
 reach it, in short, conscious and unconscious sensations. 
 From the above the measurement formula may be considered 
 well founded. 
 
 In the measurement formula one has a general dependent rela- 
 tion between the size of the fundamental stimulus and the size of the 
 corresponding sensation and not one which is valid only for the 
 cases of equal sensations. This permits the amount of sensation to 
 be calculated from the relative amounts of the fundamental stimu- 
 lus and thus we have a measurement of sensation.
 
 HERMANN VON HELMHOLTZ 
 
 (1821-1894) 
 
 A MANUAL OF PHYSIOLOGICAL OPTICS 
 
 THEORY OF COLOR VISION 
 
 HYPOTHESES. The facts to be deduced from the laws of 
 color-mixture, that three constituents of sensation which 
 proceed independently of one another are produced by exter- 
 nal stimulation, have received their more definite and more sig- 
 nificant expression in the hypotheses, which assume, that these 
 different constituents are excited and transmitted in different 
 portions of the optic nerve; but that they simultaneously attain 
 to consciousness, and thereby, so far as they have become 
 excited from the same place of the retina, they are also localized 
 in the same place of the field of vision. 
 
 Such a theory was first proposed by Thomas Young. 1 The 
 more detailed development of it is essentially conditioned by 
 
 * From H. von Helmholtz's Handbuch der Physiologischen Opiik. Leipzig, 
 1856-66; 2te. umgearb. Aufl. Hamb. u. Lpz. 1896. 
 
 1 Thomas Young's theory of color vision is as follows: "From three simple 
 sensations, with their combinations, we obtain seven primitive distinctions of 
 colours; but the different proportions, in which they may be combined, afford a 
 variety of traits beyond all calculation. The three simple sensations being red, 
 green, and violet, the three binary combinations are yellow, consisting of red and 
 green; crimson, of red and violet; and blue, of green and violet; and the seventh 
 in order is white light, composed by all three united. But the blue thus produced, 
 by combining the whole of the green and violet rays, is not the blue of the spect- 
 rum, for four parts of green and one of violet make a blue differing very little 
 from green; while the blue of the spectrum appears to contain as much violet as 
 green : and it is for this reason that red and blue usually make a purple, deriving its 
 hue from the predominance of the violet." Thomas Young's A Course of Lec- 
 tures on Natural Philosophy. Lond. 1807, vol. i, p. 440.
 
 574 HERMANN VON HELMHOLTZ 
 
 the fact, that its author would ascribe to the sensitive nerves of 
 the eye only the properties and capacities, which we positively 
 know as belonging to the motor nerves of men and of animals. 
 We have a much more favorable opportunity to discover these 
 latter by experiment than is the case with the nerves of sensa- 
 tion, since we are able comparatively easily and definitely both 
 to discern and to measure the finest changes of their excitation 
 and excitability by means of the contractions occurring in the 
 muscles, and their changes. What we furthermore have been 
 able to ascertain concerning the structure, the chemical consti- 
 tution, the excitability, the conductivity, and the electrical 
 behavior of the sensitive nerves, harmonises so perfectly with 
 the corresponding behavior of the motor nerves, that funda- 
 mental differences in the nature of their activity are extremely 
 improbable, at least so far as these do not depend upon the other 
 organic apparatus connected with them, upon which they exert 
 their influence. 
 
 Now we know in regard to motor nerves only the contrast 
 between the state of rest and of activity. In the former state 
 the nerve can remain unaltered a long time without important 
 chemical change or development of heat; and at the same time 
 the muscle dependent upon the nerve remains lax. If we stimu- 
 late the nerve, heat develops in it material changes, electrical 
 oscillations are shown, and the muscle is contracted. In a 
 cut nerve-preparation the sensitiveness is quickly lost, prob- 
 ably on account of the expansion of the chemical constituents 
 necessary for activity. Under the action of atmospheric oxygen, 
 or better still of the arterial blood containing oxygen, the sensi- 
 tiveness is wholly or partially slowly restored, save that these 
 processes of restoration excite contractions of the muscle, or 
 changes of electrical relation in nerve and muscle coincident 
 with the activity. We are acquainted also with no external 
 means which can produce this process of restoration so 
 quickly and intensively, and which can permit it at the same 
 time so suddenly to appear and again to cease, as would be 
 necessary, if this process were to serve as the physiological 
 basis of a powerful sensation occurring with precision.
 
 MANUAL.OF PHYSIOLOGICAL OPTICS 575 
 
 If we confine our assumptions concerning the development of 
 a theory of cplor vision to the properties belonging with cer- 
 tainty to the nerves, there is presented in fairly secure outline 
 the theory of Thomas Young. 
 
 The sensation of dark corresponds to the state of rest of the 
 optic nerve, that of colored or white light to an excitement of 
 it. The three simple sensations which correspond to the excite- 
 ment only of a single one of the three nerve systems, and from 
 which all the others can be composed, must correspond in the 
 table of colors to the three angles of the color triangle. 
 
 In order to assume the finest possible color sensations not 
 demonstrable by objective stimulus, it appears appropriate so 
 to select the angles of the color triangle that its sides include in 
 the closest possible way the curves of the colors of the spectrum. 
 
 Thomas Young has therefore assumed : 
 
 1. There are in the eye three kinds of nerve fibres. The ex- 
 citation of the first produces the sensation of red ; the excitation 
 of the second, the sensation of green; the excitation of the 
 third, the sensation of violet. 
 
 2. Objective homogeneous light excites these three kinds of 
 fibres with an intensity which varies according to the length 
 of the wave. The fibres sensitive to red are excited most 
 strongly by light of the greatest wave-length ; and those sensi- 
 tive to violet by light of the smallest wave-length. Neverthe- 
 less, it is not precluded, but rather to be assumed, for the expla- 
 nation of a series of phenomena, that each color of the spectrum 
 excites all the kinds of fibres, but with different intensity. If we 
 suppose in Fig. i the spectrum colors placed horizontally and in 
 their natural order, beginning from red R up to violet V, the 
 three curves may represent more or less exactly the strength 
 of the excitation of the three kinds of fibres: no. i those sensi- 
 tive to red; no. 2 those sensitive to green; and no. 3 those sen- 
 sitive to violet. 
 
 The simple red excites strongly the fibres sensitive to red, 
 and weakly the two other kinds of fibres; sensation: red. 
 
 The simple yellow excites moderately the fibres sensitive to 
 red and green, weakly the violet; sensation: red.
 
 576 HERMANN VON HELMHOLTZ 
 
 The simple green excites strongly the fibres sensitive to green, 
 much more weakly the two other kinds; sensation: green. 
 
 The simple blue excites moderately the fibres sensitive to 
 green and violet, weakly the red; sensation: blue. 
 
 The simple violet excites strongly the fibres which belong to 
 it, and weakly the others; sensation: violet. 
 
 The excitation of all the fibres of nearly equal strength gives 
 the sensation of white, or of whitish colors. 
 
 Perhaps it may be objected at first view to this hypothesis, 
 that three times the number of nerve fibres and nerve endings 
 must be presumed than in the older assumption, according to 
 which each separate nerve fibre was thought capable of trans- 
 mitting all kinds of chromatic excitations. But I do not believe, 
 that in this connection the supposition of Young is in contra- 
 diction with the anatomical facts. An hypothesis was previ- 
 ously discussed, 1 which explains the accuracy of sight by the 
 aid of a much smaller number of visual nerve fibres, than the 
 number of distinguishable places in the field of vision. 
 
 The choice of the three fundamental colors seems at first, as 
 we have observed, somewhat arbitrary. Any other three colors 
 might be chosen from which white can be composed. Young 
 was guided probably by the consideration that the colors at the 
 end of the spectrum appear to claim a privileged position. If we 
 were not to select these it would be necessary to take for one of 
 the fundamental colors a purple shade, and the curve which cor- 
 
 1 Helmholtz's Hdb. d. Physiol. Optik. 2 Aufl., S. 264.
 
 MANUAL OF PHYSIOLOGICAL OPTICS 577 
 
 responds to it in the foregoing figure (Fig. i), would have two 
 maxima: one in red, and the other in violet. 
 
 The single, circumstance, which is of direct importance in the 
 mode of sensation and appears to give a clue for the determina- 
 tion of the fundamental colors, is the apparent greater color- 
 saturation of the red and violet; a thing which also manifests 
 itself, although indeed less markedly, for green. Since we style 
 colors the more saturated the farther they are removed from 
 white, we must expect that great saturation must belong partic- 
 ularly to those colors of the spectrum which produce most 
 purely the simplest sensations of color. In fact, these colors, if 
 they are very pure, have even with inferior brilliancy, some- 
 thing of an intensively glowing, almost dazzling quality. 
 There are especially red, violet, or blue violet flowers, e.g. of the 
 cameraria, whose colors display this characteristic blending of 
 darkness and brilliancy. Young's hypothesis affords for this a 
 simple explanation. A dark color can cause an intensive excita- 
 tion of one of the three nerve systems, while the corresponding 
 bright white causes a much weaker excitation of the same. The 
 difference appears analogous to that between the sensation of 
 very hot water upon a small portion of the skin and lukewarm 
 water striking a greater surface. 
 
 In particular violet makes upon me this impression of a deeply 
 saturated color. But inasmuch as the strictly violet rays, even 
 when they occur in sunlight, are of slight intensity and are 
 modified by fluorescence, ultramarine blue, which has far the 
 advantage of greater intensity of light, produces an effect ap- 
 proximately equal to it. The strictly pure violet of the spectrum 
 is very little known among the laity, since the violet pigments 
 give nearly always the effect of a slight admixture of red, or 
 appear very dark. For that very reason, the shades of the ultra- 
 marine blue coming near to the violet excite the general atten- 
 tion much more, are much better known, and are designated 
 by a much older name, that of blue, than the violet strictly 
 so called. In addition one has in the deep ultramarine blue of 
 the cloudless sky a highly imposing, well known, and constant 
 example of this color.
 
 578 HERMANN VON HELMHOLTZ 
 
 In this fact I seek the reason why in former times blue has 
 always been regarded as the one fundamental color. And the 
 more recent observers, like Maxwell and A. Konig, who have 
 sought to determine the composition of color, have also in 
 part returned to it. For both of these had, to be sure, a more 
 definite reason in the above mentioned elevation of the curve 
 of the colors of the spectrum in violet. 
 
 It should still be mentioned that the Venetian school of 
 painters, which creates effects chiefly by the intense richness of 
 its color, is especially fond of putting in juxtaposition the three 
 colors, red, green, and violet. 
 
 Furthermore, I decidedly question the opinion expressed by 
 various investigators, that the need of designating primary 
 sensations has manifested itself in the names of the colors, and 
 that these might therefore give a clue for the determination of 
 colors. Our forefathers had before them in colors a domain of 
 vague distinctions. If they wanted to determine sharp degrees 
 of difference they had first of all to look for good old examples 
 of striking shade, which were everywhere known, and any- 
 where observable. The names for red led back to the Sanscrit 
 rudhira = blood, and also "red." From this epvdpos-, rufus, 
 ruber, roth, red, etc. For "blue" the Greeks have 7ro/3</>i5/oeo<? 
 and Kuctfeo?, which appear to refer to the sea; the Latins 
 coeruleus, from ccelum, the sky; the Germans "blau"; the 
 English, blue; the Dutch, blau; the old German, blaw; which 
 appear to lead to the English "blow," that is, the color of the 
 air. The names for green may be traced back to vegetation, 
 irpdfflvos (leek-green), TrooiSe? (grass-green), viridis from vis, 
 virescere (to grow strong) ; German: green, English: green, refer 
 to "grow." 
 
 The oldest designations of color were very vague: gavQo? 
 appears to have extended from golden yellow to blue green. It 
 was clearly a difficult task to fix in sharp degrees of difference 
 this vague domain. To-day even it is difficult for gifted children 
 to learn the names of colors. One should not infer from these 
 facts that the ancients were color blind. 
 
 That from the series of colors which may be stimulated by
 
 MANUAL OF PHYSIOLOGICAL OPTICS 579 
 
 objective light, it is impossible to select three which can be 
 regarded as fundamental sensations, has already been dis- 
 cussed. For this very reason A. Konig and C. Dieterici have 
 distinguished a middle section of the spectrum, the colors of 
 which we can no longer obtain by the mixture of the end-colors 
 and one of the spectrum colors lying within it. The table of 
 colors drawn according to the measurements of the same ob- 
 servers reveals the same fact in graphic representation. Just 
 on this account the supposition is necessary for Thomas 
 Young's theory, that every color of the spectrum excites simul- 
 taneously, even though in different intensity, not merely one, 
 but two or all three, of the three nerve systems which are sensi- 
 tive to color. At best the hypothesis of simplicity would be 
 permissible for the end-colors of the spectrum, red and violet. 
 But precisely in the case of violet we know, that the fluores- 
 cence of the retina produced by the violet rays must vitiate the 
 sensation, and it appears to me not improbable, that the height 
 of the curve between F and Y, found even by Maxwell, is con- 
 ditioned by the fluorescence of the retina. 
 
 It further follows, that it must appear theoretically possible 
 to produce sensations of more saturated colors through other 
 conditions of excitation. That this is also practically possible, 
 and that this demand can be actually fulfilled by Young's 
 theory,! shall have to explain in the description of after-images. 
 
 The color theory of Thomas Young, above outlined, is, as 
 compared with the general theory of nervous activity as it was 
 worked out by Johannes Miiller, a more special application of 
 the law of specific sensations. Corresponding to its hypotheses 
 the sensations of red, green, and violet would be regarded as 
 determined by the specific energy of sensation of the correspond- 
 ing three nerve systems. Any sort of excitation whatever, 
 which can in any degree excite the nerve system aforesaid, 
 would always be able to produce in it only its specific sensa- 
 tion. As for the cause of the particular quality of these sensa- 
 tions we hardly need look for it in the retina or the constitution 
 of its fibres, but in the activity of the central parts of the brain 
 associated with them.
 
 580 HERMANN VON HELMHOLTZ 
 
 I have up to the present kept the analysis of this theory relatively 
 abstract in order to keep it as free as possible from farther hypothet- 
 ical additions. Nevertheless, there are as great advantages for the 
 certain understanding of such abstractions, if one tries to imagine 
 for oneself pictures as concrete as possible, even though these occa- 
 sion many a presupposition that is not directly necessary for the na- 
 ture of the case. In this sense I permit myself to set forth Young's 
 theory in the following somewhat more manifest form. That objec- 
 tions to these additions do not contradict the essence of Young's 
 hypothesis, I have no need to explain. 
 
 1. Three kinds of photochemically decomposible substances are 
 deposited in the end organs of the visual nerve fibres, which have 
 different sensitiveness for the different parts of the spectrum. The 
 three color values of the colors of the spectrum depend essentially 
 upon the photochemical reaction of these three substances to the 
 light. In the eyes of birds and reptiles besides colorless cones there 
 occur in fact rods with red, and rods with yellow-green, drops of oil, 
 which might produce a favoring of some simple light in their action 
 upon the back element of these formations. In the case of human 
 beings and other mammals nothing similar has up to the present 
 time been found. 
 
 2. By the disintegration of all the substances sensitive to light, 
 the nerve fibre laden therewith, is set into a state of excitation. 
 There is only one kind of activity capable of exciting sensation in 
 every nerve fibre which accompanies the disintegration of the 
 organic substance and the development of heat, as we know from 
 our study of the nerves of muscles. These phenomena in the three 
 systems of fibres are probably also thoroughly similar one to the 
 other. They act differently in the brain only for the reason that they 
 are united to different functioning parts of the brain. The nerve 
 fibres need here as everywhere to play only the part of conducting 
 wires, by which entirely similar electric currents which pass through 
 them can precipitate or call forth the most various activities in the 
 apparatus connected with the ends. These excitations of the three 
 systems of fibre form the above separated three elementary excita- 
 tions, provided always that the intensity of excitation, for which 
 we still have no universally valid measure, is thereby made propor- 
 tional to the strength of light. This does not prevent the intensity 
 of the elementary excitation being any involved function whatever 
 of the use of material or of the negative variation of the current in
 
 MANUAL OF PHYSIOLOGICAL OPTICS 581 
 
 the nerves, which latter phenomena might occasionally be employed 
 as a measure of excitation. 
 
 3. In the brain the three systems of fibres stand in alliance with 
 the three different functioning systems of ganglionic cells, which are 
 perhaps spatially so close to one another, that those corresponding 
 to the same parts of the retina lie close together. This appears to 
 follow from recent investigations concerning the influence of lesions 
 of the brain upon the field of vision.
 
 EWALD HERING 
 
 THEORY OF LIGHT SENSATION 
 
 Translated from the German * by 
 BENJAMIN RAND 
 
 FUNDAMENTAL PRINCIPLES OF A THEORY OF 
 LIGHT SENSATION 
 
 25. PREFATORY REMARKS 
 
 ALTHOUGH strictly speaking a theory of light sensation has 
 to consider all visual sensations, I mean here chiefly to con- 
 sider only the sensations of white, black, and the transitions 
 from one to the other, that is to say, only the colorless, or, as I 
 have termed them (21), white-black sensations. Later,! shall 
 enter upon a special discussion of color-sensations in the 
 stricter sense of that term. 
 
 Colors, to be sure, are everywhere intermingled, and espe- 
 cially in the after-images of the closed eye; but I shall wholly 
 disregard color in all such more or less colored sensations, and 
 confine myself only to that which can be designated as the 
 whitishness or blackishness of sensation. Later it will appear, 
 that this special consideration of the sensations of colorless 
 light even has its complete theoretical justification. 
 
 The sensation of white or colorless light has been regarded as 
 a mixed sensation, because it is produced by a simultaneous 
 effect of so called complementary kinds of light upon the retina. 
 Nevertheless we see simultaneously in white, neither yellow and 
 blue, nor red and green, nor any other two complementary 
 
 * From E. Bering's Zur Lehre vom Lichtsinne, (Sitzber. Akad. Wiss. Wien, 
 math.-naiurw. Cl., LXVI-LXX.) Wieo. 1872-74; ib. 1878.
 
 THEORY OF LIGHT SENSATION 583 
 
 colors, but at most the white shades off into yellow or blue, red 
 or green, never, however, into two complementary colors. The 
 designation of white, therefore, as a sensation of red and green, 
 or yellow and blue, or of all colors simultaneously mixed, ap- 
 pears inadmissible, and has indeed arisen only from the ab- 
 stract confusion of sensations with their causes. Not everyone, 
 who has termed white a mixed sensation, meant to say that the 
 sensations were actually mixed, but only, that in order to excite 
 the sensation of white we must mix light of different wave 
 lengths. This sensation aroused by the simultaneous reaction 
 of divers kinds of rays can very well be regarded as a simple 
 resultant of mingled physical causes. 
 
 The Young-Helmholtz hypothesis can only in this sense be 
 acceptable to a certain extent. For if we were to say to a dis- 
 interested person, even though he had a highly developed sense 
 of color such as a painter has, that white is a compound sensa- 
 tion in which one perceives not only simultaneously, but also 
 with equal intensity, red, green, and violet, he would reply with 
 an incredulous shake of the head, or, if he felt no special respect 
 for the trustworthiness of science, with a smile. That three tones 
 of different pitch are contained in a triad, everyone hears who 
 is skilled in music, though only in a slight degree; but no one is 
 able, try as he may, to extract the sensations of red, green, and 
 violet, from one and the same white. 
 
 To one, who enters upon the investigation of his visual 
 sensations without physical or physiological presuppositions, 
 white is a sensation of its own kind, just as black, red, green, 
 yellow, and blue. Something can be combined with the white 
 from one or the other, or even from several of the last men- 
 tioned sensations so that it more or less clearly reminds us of 
 them. If, however, we imagine these intermingled traces of 
 other sensations to be absent, a sensation is left of an entirely 
 specific and pure quality, which decidedly gives the impression 
 of something simple, and which the unprejudiced sees no oc- 
 casion whatever to regard as compound. The same, moreover, 
 is quite true of the sensation of black. 
 
 Since the physiologist must deem all sensations as conditioned
 
 584 EWALD HERING 
 
 and supported by physical processes of the nervous system, 
 because otherwise every further physiological investigation 
 would be useless, he must also accept the so-called psycho- 
 physical processes or movements, which correspond to the sen- 
 sations of black, of white, and of all transitions from one to the 
 other. It is not possible to say as yet in what part of the nerv- 
 ous system these psychophysical processes are to be conceived 
 as localized. Suffice it to say, that somewhere in the nervous 
 apparatus of the eye and the parts of the brain standing in 
 functional connection therewith, the substance must be sought 
 with whose change or movement sensation is connected. This 
 substance we might designate as the psychophysical substance 
 of the organ of sight relative to the brain. It will be shorter to 
 designate it as the visual substance, because the visual sensa- 
 tions are connected with it and immediately dependent upon it. 
 Whether this visual substance is to be sought only in the brain, 
 or likewise in the nerves of sight, and in the retina, and in what 
 histological constituents of the same, all this remains out- 
 side the present discussion. 
 
 It is manifest, that we can draw conclusions at first only from 
 the nature and course of our visual sensations in regard to the 
 course of the psychophysical processes, which occur in the 
 visual substance; for with these the sensations are to be re- 
 garded as immediately and legitimately connected. If we can 
 determine in this way to a certain extent the laws of psycho- 
 physical reactions in the visual substance, not until we do is it 
 in order for us to seek the laws of functional relation between 
 those psychophysical processes and the vibrations of aether. 
 The reverse method which proceeds from the vibrations of 
 aether has led heretofore to no result, so far as it has dealt not 
 merely with the vicissitudes of the rays of light in the optical 
 media, that is to say exclusively with an application of phys- 
 ical optics to the eye. We know nothing at all of what takes 
 place after the light waves have penetrated the retina. On the 
 other hand we certainly obtain through numerous physical 
 investigations the most valuable conclusions concerning the 
 relations between the vibrations of aether and visual sensa-
 
 THEORY OF LIGHT SENSATION 585 
 
 tions. But all physiological links and especially their psycho- 
 physical processes have been simply ignored in these investiga- 
 tions, as was quite appropriate under the circumstances of a 
 preliminary research. 
 
 Only the psychophysical investigations, especially Fechner's, 
 have a closer regard to the physiological intermediaries, espe- 
 cially in so far as Fechner proposed a law of functional connec- 
 tion between the psychophysical movement and the so called 
 intensity of sensations. I refer to that psychophysical law 
 called by Fechner's name,* the validity of which I must chal- 
 lenge not merely for the sense of sight, but for the domain of all 
 the senses. 
 
 5 26. THE NATURE OF THE PSYCHOPHYSICAL 
 PROCESSES 
 
 If we desire to form an idea of the nature of the psychophy- 
 sical processes, we have from the outset a choice between such 
 inner movements of the psychophysical, or (briefly) psychical 
 substance, as occur without change of chemical composition, 
 and such movements as appear to be at the same time changes 
 of chemical composition. The physiologist of the present can 
 nevertheless no longer be in doubt about his decision. For the 
 general physiology of the nerves has sufficiently proven, that 
 every movement or activity of the nervous substance changes 
 it at once chemically; and upon the hypothesis of chemical 
 changes all our ideas of changes of sensitiveness, fatigue, and 
 recuperation after activity are based. 
 
 How Du Bois-Reymond f could propose a purely physical 
 hypothesis concerning processes in the nerve-fibres -becomes 
 conceivable, when you consider that he aimed in reality only 
 at the explanation of what the multiplicator testified to him 
 about the processes in the nerves. If he had had for the changes 
 of the nerve as fine a chemical reagent, as he possessed in the 
 
 * Supra, p. 570. 
 
 f Cf. Emil du Bois-Reymond's Untersuchungen iiber thierische Electricitttl, 
 Berlin, 1848-49.
 
 586 EWALD HERING 
 
 multiplicator an electrical one, he would then of course have 
 proposed a chemical hypothesis. At all events, the hypothesis 
 of Du Bois-Reymond does not form a conclusive objection 
 against my affirmation, that according to our present knowledge 
 the activity of the psychophysical substance is not easily con- 
 ceivable without simultaneous chemical changes. 
 
 The hypothesis developed in Fechner's psychophysics, ac- 
 cording to which all psychophysical processes are regarded as 
 oscillatory movements of a substance not more exactly to be 
 designated as ponderable or imponderable, also cannot be 
 cited against the above affirmation. For first, the hypothesis 
 according to the whole nature of the case rests upon only an 
 empirical basis which up to the present is very narrow; and 
 secondly, although it is purely mechanical, it still permits to the 
 chemical processes their significance in psychical happening, 
 and, so to speak, includes them. 
 
 In whatever way one may regard these questions this much 
 is certain, that the continuous existence of chemical process is 
 in every living and consequently sensitive substance a fact, and 
 transformation is for us the most universal known characteris- 
 tic of living things. 
 
 So much in the way of proof for the justification by prin- 
 ciple of the following theory, which is related primarily to the 
 chemical action in the nerve substance. A definite view as to 
 whether we actually apprehend in this chemical action the 
 real psychophysical movement, or whether an intermediate 
 link intervenes, as it were, between this and the sensation, I do 
 not for the present mean to have said. Furthermore, it was by 
 no means my intention in this brief discussion to enter upon 
 a real investigation of the difficult question concerning the 
 nature of psychophysical movement. On the contrary, it was 
 intended only to show that the physiologist is perfectly right 
 in conceiving the life of the nerve-substance primarily as 
 chemical, and likewise that of the psychophysical substance, 
 which even, if one does not insert a new and completely un- 
 known link, must be wholly or partially identified with the 
 nerve substance.
 
 THEORY OF LIGHT SENSATION 587 
 
 27. VISUAL SENSATION AS PSYCHICAL 
 
 CORRELATE OF CHEMICAL PROCESSES IN THE 
 
 VISUAL SUBSTANCE 
 
 That light occasions chemical changes in the nervous ap- 
 paratus of the visual organ will probably not be disputed after 
 what has been said. What we term fatigue and in general change 
 of sensitivity of this process rest according to the universal 
 view, here as everywhere, upon chemical change of a sensitive 
 substance. Fechner himself, who sought to develop farther the 
 theory of resonance proposed by the physicists Herschell, 
 Melloni, and Seebeck, for the excitation of the retina by light, 
 saw occasion to take account of the chemical influences of light 
 upon the nerve substance and to include them in his reckoning. 1 
 
 The chemical processes occasioned by light in the visual 
 organ were first regarded as localised in the retina. But if cer- 
 tain parts of the brain participate in the production of visual 
 sensations and representations, those chemical processes of the 
 retina must on their part also occasion chemical changes in the 
 substance of the visual nerve, and these in turn in the substance 
 of the brain. Since, however, as already stated, we do not know 
 whether we have to consider the entire substance of the visual 
 organ, or only a part of it, and in the latter instance which part, 
 as the true psychophysical visual substance, we must for the 
 present be content with the current hypothesis, that the vibra- 
 tions of aether set free in general chemical changes in the nerv- 
 ous visual apparatus. And those changes, whether the series 
 of these chemical processes be long or short, whether it be com- 
 posed of similar or dissimilar members, lead finally to sensation. 
 
 Furthermore, whatever ideas of the nature and place of the 
 processes occurring in the visual organ investigators enter- 
 tained, one thing was lacking to all: viz., they merely conceived 
 the sensations of bright or white color here too I entirely dis- 
 regard as conditioned by and based upon certain changes of 
 the visual substance; the sensation of dark or black in reference 
 1 Psychophysik, u. Theil, 283.
 
 588 EWALD HERING 
 
 to its physiological or psychophysical correlate was entirely 
 neglected. How this came about, and to what contradictions 
 this onesided consideration of the sensation of brightness led, I 
 have more fully set forth in my foregoing chapter ( 21-23). 
 The facts there developed compel us henceforth to abandon 
 this onesided attitude in the investigation of the visual sensa- 
 tions, and to give an equal consideration to the two chief varia- 
 bles in visual sensation, the dark or black, just as much as the 
 bright or white. 
 
 I have explained in 21, how all sensations of the black-white 
 series of sensations appear related to one another in a twofold 
 manner, and have in common two different kinds of factors, 
 namely, the sensation of brightness and of darkness, the black 
 and the white. I have also set forth how each member of this 
 sensation series can be characterised by the relation in which 
 both these factors are contained in the given sensation. If now 
 we ask concerning the psychical correlates of those sensations, 
 and concerning the psychophysical or psychochemical processes 
 lying at their basis; not only does the hypothesis, that the 
 physical correlate of the blackest sensation is nothing further 
 than the lowest degree of intensity of the same process which 
 conditions in its highest intensity the clearest or purest white 
 sensation, have nothing in its favor, but even appears to be 
 extravagant and contradictory. For this hypothesis demands 
 one and the same kind of psychophysical process for two clearly 
 fundamentally different qualities of sensation. But our entire 
 psychophysics is based upon the hypothesis, that there exists 
 a certain parallelism between physical and psychical events, 
 and especially that to different qualities of sensation there cor- 
 respond different qualities or forms of psychophysical phe- 
 nomena. 1 
 
 1 Although this ought to be self evident to everyone who accepts a legitimate 
 functional relation between psychical and physical, between sensation and nerve 
 process, it still has often been forgotten, and even Fechner, although he is guided 
 by the same presupposition, nevertheless makes, as I deem, too little application 
 of it. Mach styles this fundamental presupposition of the entire psychophys- 
 ics merely as " a heuristic principle of psychophysical research"; but it is more, 
 it is the conditio sine qua non of all such research, if it is to bear any fruit. Mach
 
 THEORY OF LIGHT SENSATION 589 
 
 If we do not desire, therefore, at the outset to introduce in 
 like manner into this difficult domain an hypothesis which 
 stands in a yet unsolved contradiction to the fundamental 
 presupposition of the entire science of psychophysics, and pro- 
 bably furnishes a bad precedent for other wholly capricious 
 and theoretically improbable hypotheses, we must abandon 
 the present current view. And we can do this the more readily 
 as another hypothesis presents itself which is thoroughly in 
 accord with the aforementioned presupposition of psychophys- 
 ics, and at the same time satisfies far better than the present 
 theory the demands which must be taken into consideration 
 from the point of view of the general physiology of the nerves. 
 This hypothesis is the following: 
 
 To the two qualities of sensation, which we designate as white 
 or bright and as black or dark, correspond two different quali- 
 ties of chemical activity in the -visual substance; and to the 
 different relations of brightness or intensity, with which these 
 two sensations appear in single transitions between pure white 
 and pure black, or to the relations in which they appear mixed, 
 correspond the same relations of intensities of those two psycho- 
 physical processes. 
 
 It will be readily acknowledged after reflection, that this 
 hypothesis is the simplest there is, because it states the sim- 
 plest formula that can be conceived for the functional connec- 
 tion between physical and psychical phenomena. 
 
 But it also satisfies every demand that the general physio- 
 remarks (Uberd. Wirk,d. rauml, Verlheil. d. Lichlreizes auf die Nelzhaui. Sitzungs- 
 ber.d. Akad. 52 Bd., 1868). "To every psychical there corresponds a physical, and 
 the reverse. To like psychical processes there correspond like physical, to unlike, 
 unlike. If a psychical process can be resolved in a purely psychological way into 
 a number of qualities a, b, c, there will correspond to these likewise an equal 
 number of different physical processes a, /8, y. To all details of the psychical there 
 correspond details of the physical." Barring the omission from the statement, of 
 all reference to the fact that psychophysical processes of very different size can 
 produce the same sensation, because it depends everywhere not upon the abso- 
 lute size of this process, but solely upon their reciprocal relation (cf. 5 29), I can 
 entirely accept these words of Mach. 
 
 My theory of the spatial sense of the retina was founded upon the same princi- 
 ple. Mach is the only one who has concurred in its fundamental thought.
 
 590 EWALD HERING 
 
 logy of the nerves can make. We must suppose a substance in 
 the nervous visual apparatus, which suffers change under the 
 influence of the light that falls upon it, and this change, even 
 though it may be characterised as physical, is nevertheless, as 
 the physiology of the nerves must assume, at the same time a 
 chemical process. If the action of the light ceases, the changed 
 (more or less exhausted) substance reverts sooner or later to its 
 original condition. This reversion can in turn be nothing but 
 a chemical change in the opposite direction. If the occurring 
 change of the excitable substance under the direct influence of 
 light is conceived as a partial consumption, the reversion to the 
 former condition must be conceived as a restitution; and if the 
 former is viewed as an analytic process, the latter must be 
 viewed as a synthetic process. 
 
 It has also been customary to designate the latter process, by 
 means of which the living organic substance again restores the 
 loss suffered by excitation or activity as assimilation, and I will 
 retain this expression. Now every living and excitable organic 
 substance forms in the excitation or activity according to 
 general assumption certain chemical products. The formation 
 of these products I will designate analogously as the process of 
 dissimilation. 
 
 The propositions concerning assimilation (A) and dissimila- 
 tion (D) just set forth are derived from the experiences of gen- 
 eral physiology, and particularly of the physiology of the 
 nerves. They have, therefore, been developed wholly inde- 
 pendently of our hypothesis. Granted their correctness, it is by 
 no means plausible, that merely the one kind of chemical 
 activity in the visual substance, namely dissimilation, should 
 have a psychophysical significance, but the other, the process 
 of assimilation, none. The common view, that the chemical 
 process taking place under the direct influence of light, namely 
 dissimilation, is alone perceived, is clearly onesided and unjusti- 
 fied. On the contrary, it appears from the outset proper to 
 ascribe an equal value for sensation to both kinds of chemical 
 process. But this leads to none other than the hypothesis above 
 formulated. For we need only to make this hypothesis still
 
 THEORY OF LIGHT SENSATION 591 
 
 more precise, by saying, that the dissimilation of the visual 
 substance corresponds to the sensation of white or bright, and 
 the assimilation of the visual substance to the sensation of black 
 or dark ; and then the hypothesis, as I shall show, satisfies not 
 only the facts of sensation, but also the demands of the general 
 physiology of the nerves. 
 
 If my hypothesis is correct we have the means, through the 
 visual sensations, of observing closely the " building up" process 
 of the visual substance, and its two principal factors, assimilation 
 and dissimilation. We do not, therefore, deal hereafter only with 
 the fact, that a complex of sensations is transmitted from the 
 eye to the human soul, which afterwards moulds it into present- 
 ations by the aid of correct or false judgments or inferences; 
 but what comes to consciousness as visual sensation is the 
 physical expression or the conscious correlate of the chemical 
 change of the visual substance. 
 
 We have, therefore, a test of great sensitiveness for this 
 chemical change, namely our consciousness. It tells us, indeed, 
 nothing directly concerning the nature of the chemical com- 
 pounds or disintegrations, but it reveals to us the whole tem- 
 poral process of assimilation and dissimilation, the law of their 
 dependence upon one another and upon the vibrations of aether, 
 the elevation and depression of excitability of the visual sub- 
 stance, and the dependence of these changes of excitability 
 upon assimilation and dissimilation. In this way the chapter on 
 visual sensations first becomes a truly integral section of 
 physiology, whereas heretofore it necessarily contained more 
 physical and philosophical, than strictly physiological dis- 
 cussions. 
 
 From the above hypothesis we derive, as is shown in what 
 follows, a complete series of propositions concerning fatigue, 
 excitability, chemical change of the visual substance, which are 
 in harmony with certain propositions of the general physiology 
 of the nerves ; but we are able also in addition to give to those 
 propositions in part a more precise expression, as well as to test 
 certain new propositions, which follow as the result of our 
 hypothesis, in regard to other excitable substances. In brief, a
 
 592 EWALD HERING 
 
 way opens up for the further development of the general 
 physiology of the nerves, also of the physiology of the " ex- 
 citable " substances, and finally of the doctrine of the whole 
 organic life. That this way is not improbable, I hope to demon- 
 strate in later chapters on several subjects in physiology. 
 
 We have employed our sense-perceptions so abundantly in 
 order to comprehend our external world, and they make it 
 serviceable to us; let us now employ them also in order to in- 
 vestigate the material activity of our own body, examining first 
 by their aid what we feel, not as the external objects only medi- 
 ately, but immediately, that is to say, the chemical change of 
 our nervous system. 
 
 28. THE DEDUCTION OF VARIOUS COROL- 
 LARIES 
 
 In my fourth chapter I derived by means of an analysis of 
 visual sensations, independent of every physical or physiolog- 
 ical presupposition, the proposition, that every sensation of col- 
 orless light is determined by the relation of the perceptible 
 black to the simultaneous perceptible white in it, and that this 
 relation determines the quality brightness or darkness of 
 every white-black sensation. 
 
 If we now apply to this problem the hypothesis advanced in 
 the preceding section, we come to the further proposition that 
 the quality brightness or darkness of a sensation of 
 colorless light, is conditioned by the relation in which the in- 
 tensity or extent of dissimilation of the visual substance stands 
 to the intensity or degree of its simultaneous assimilation. 
 
 From this it follows further, that to the gray, which I have 
 designated as the middle or neutral, corresponds that condition 
 of the visual substance in which dissimilation and assimilation 
 are in equilibrium, so that the quantity of the excitable sub- 
 stance remains constant. 
 
 Further it follows, that in every rather bright sensation the 
 dissimilation is greater than the assimilation, so that the 
 excitable substance decreases; and the more rapidly, the greater
 
 THEORY OF LIGHT SENSATION 593 
 
 IV 
 
 the relation 3, or the brighter the sensation is, and so much 
 
 the more, the longer it continues. 
 
 On the contrary it follows, that in every sensation, which is 
 darker than the middle gray, the dissimilation is smaller than 
 the simultaneous assimilation, so that the excitable substance 
 increases; and, indeed, the more rapidly, the darker the sen- 
 sation is, and so much the more, the longer it continues. 
 
 What now does the increase or decrease of the excitable 
 substance signify? 
 
 If we style all stimuli which favor the dissimilation of the 
 visual substance, stimuli of dissimilation or D stimuli, and if we 
 borrow from general physiology the proposition, that the degree 
 of the reaction with which an organ responds to a stimulus 
 depends among other things upon the quantity of excitable 
 substance contained in it and affected by the stimulus, we ar- 
 rive at the farther proposition, that the degree of the dissimila- 
 tion conditioned by a D stimulus (e.g., light) depends not 
 merely upon the degree of the stimulus, but also upon the quan- 
 tity of the excitable substance contained at any time in the 
 stimulated portions and affected by the stimulus. 
 
 The capacity of an excitable substance to become excited by 
 stimuli, that is, to respond to these stimuli by a definite chemi- 
 cal process, we term its excitability. Accordingly, we can desig- 
 nate the capacity of the visual substance to react upon the D 
 stimuli with dissimilation as its D excitability, and can now 
 also express the foregoing proposition as follows: 
 
 Every increase of the excitable substance conditions an en- 
 hancement, and every decrease a depression, of the D excita- 
 bility in the corresponding part of the visual organ. 
 
 It follows further, that the sensation of medium gray condi- 
 tions an equilibrium, every rather bright sensation a decrease, 
 every rather dark sensation an increase, of the D excitability of 
 the affected part. 
 
 If sensations of different degrees of brightness or darkness 
 are simultaneously produced in two places of nearest equal 
 D excitability, the place of the brighter (less dark) sensa-
 
 594 EWALD HERING 
 
 tion has always a smaller D excitability at the conclusion of the 
 excitation, than the place of the less bright (darker) sensation; 
 and it makes no difference whether one or both sensations 
 were brighter or darker than the neutral gray. Furthermore, 
 the remaining difference of D excitability is so much the 
 greater, as the difference was greater between the brightness of 
 both sensations, or between the values of the two corresponding 
 
 i * w j w ' 
 relations - - and . , ,. 
 s+w s'+w 
 
 Since according to what has been said the degree of dissimi- 
 lation is always dependent on the one hand upon the degree of 
 the stimulus, and upon the other hand upon the quantity of the 
 excitable substance present in the stimulated part, we have the 
 right from the outset to affirm, that the assimilation also does 
 not always occur with constant intensity, but that it has like- 
 wise a variable degree dependent upon definite conditions. 
 
 For the process of dissimilation clearly presupposes, that on 
 the one hand the necessary chemical conditions, that is to say, 
 certain substances, are present; and on the other hand certain 
 physical conditions, (such as a certain temperature). According 
 as whatever assimilation is present in greater or less degree, it 
 takes place more quickly and more abundantly, or more slowly 
 and less abundantly. The A material necessary to assimila- 
 tion, present in the visual organ, which is constantly used in 
 assimilation and constantly renewed by the blood, can become 
 more or less exhausted as soon as its consumption is greater than 
 the simultaneous restoration from the blood. For the degree of 
 the assimilation probably also depends upon the quantity of 
 the assimilative excitable substance present at the time. From 
 what precedes it is already possible quite theoretically to 
 deduce a series of propositions concerning the enhancement or 
 depression of the capacity for assimilation or of the A excita- 
 bility, and concerning the A stimuli in contrast with the D 
 stimuli, etc. Nevertheless, I shall refer for the present only to 
 such propositions from the general nerve physiology as are 
 already accepted, and shall postpone a full discussion of them 
 until later.
 
 THEORY OF LIGHT SENSATION 595 
 
 29. THE WEIGHT OF VISUAL SENSATIONS 
 
 If the brightness or darkness of a sensation of colorless light 
 depends solely upon the relation of dissimilation to the simul- 
 taneous assimilation, and is therefore independent of the abso- 
 lute magnitude of the corresponding psychophysical processes, 
 the question arises, what is the significance of this absolute 
 magnitude. Without entering here more closely into this ques- 
 tion, which belongs to general psychophysics, I shall endeavor 
 to give briefly a preliminary answer. 
 
 The absolute extent of a given psychophysical process deter- 
 mines the weight to introduce here a new expression of the 
 corresponding sensation. If two simultaneous psychophysical 
 processes of different quality lie at the basis of a sensation, as 
 for instance the gray, then the sum of the magnitudes of both 
 processes gives the weight of the resulting or mixed sensation. 
 The clearness, with which every single relatively simple sensa- 
 tion appears in such a compound sensation, depends upon the 
 relation in which its individual weight stands to the total weight 
 of the resulting or compound sensation. Thus, as we saw, the 
 brightness or whitishness of a gray sensation is determined by 
 the relation of the weight of the white sensation (or the degree 
 of dissimilation) to the total weight of the gray sensation, that 
 is, to the sum of the weights of the white and of the black sensa- 
 tion, (or of the degree of dissimilation and assimilation). 
 
 If a compound sensation, e.g., gray, is in itself a component of 
 a still more complicated compound, e.g., of gray-blue, the clear- 
 ness, with which the gray emerges in this sensation, depends 
 in turn upon the relation in which the weight of the gray sensa- 
 tion stands to the total-weight of the gray-blue. If, for example, 
 in such a sensation the blue, white, and black appear with 
 equal clearness, this depends upon the fact, that the blue, the 
 white, and the black sensation have equal weight. We can also 
 conceive such a sensation as composed of two parts of neutral 
 gray and one part of blue. The character or quality of a sensa- 
 tion is therefore independent of its total weight, but is deter-
 
 596 EWALD HERING 
 
 mined by the relation of the individual weights of the simple or 
 relatively simple sensations composing it; and the weight of a 
 black-white sensation does not gain significance until it appears 
 with other visual sensations, or in general only so far as its 
 relations to the other simultaneous processes come into con- 
 sideration. 
 
 The well informed reader must have recognised, from what 
 has already been said, the general psychophysical law, from 
 which I proceed in opposition to Fechner. This law says, 
 that the purity or clearness of any sensation or presentation 
 depends upon the relation, in which its weight, that is, the 
 degree of the corresponding psychophysical process, stands to 
 the total weight of all simultaneously present sensations and re- 
 presentations, (or however else one may denominate the psychi- 
 cal states), namely, to the sum of the degrees of all corresponding 
 psychophysical processes. 
 
 Most of the sensations, which we accept as simple, are highly complex; that 
 partial sensation, which has the greatest weight, gives the total sensation its 
 character and name. If the fragment of the total weight of a sensation, 
 belonging to one of its components, sinks below a certain value, we are no . \ 
 longer in a position to feel these components as such. Nevertheless, a weak com- 
 ponent also affects a sensation and determines by its character the quality 
 thereof. Fechner would say the partial sensation remains "below the threshold." 
 Thus every visual sensation, as I shall later seek to prove, is composed of various 
 simple sensations, and if I have here presented the sensations of the black-white 
 series as only binary sensations, it has been done provisionally in the interest of 
 simplicity of treatment. In black and white even the colors simultaneously per- 
 ceived are " below the threshold " because their relative weight is too small.
 
 ERNST MAGH 
 
 (1838- ) 
 
 CONTRIBUTIONS TO THE ANALYSIS OF 
 SENSATIONS 
 
 Translated from the German * by 
 C. M. WILLIAMS 
 
 THE SENSATIONS AS ELEMENTS 
 ANTIMETAPHYSICAL 
 
 i. THE splendid success achieved by physical science in mod- 
 ern times, a success which is not restricted to its own sphere 
 but embraces that of other sciences which employ its help, has 
 brought it about that physical ways of thinking and physical 
 modes of procedure enjoy on all hands unwonted prominence, 
 and that the greatest expectations are associated with their 
 employment. In keeping with this drift of modern inquiry, 
 the physiology of the senses, gradually leaving the paths which 
 were opened by men like Goethe, Schopenhauer, and others, 
 but with particular success by Johannes Miiller, has also as- 
 sumed an almost exclusively physical character. This tend- 
 ency must appear to us as not exactly the proper one, when 
 we reflect that physics despite its considerable development 
 nevertheless constitutes but a portion of a larger collective 
 body of knowledge, and that it is unable, with its limited in- 
 tellectual implements, created for limited and special purposes, 
 to exhaust all the subject-matter of science. Without renounc- 
 ing the support of physics, it is possible for the physiology of 
 the senses, not only to pursue its own course of development, 
 but also to afford to physical science itself powerful assistance; 
 
 * From Beilrage zur Analyse der Empfindungen. Jena, 1886: 4 verm. Aufl. 
 1903. Reprinted from E. Mach's Contributions to the Analysis of Sensations, 
 translated by C. M. Williams, Chicago, The Open Court Publishing Co., 1897.
 
 598 ERNST MACH 
 
 a point which the following simple considerations will serve to 
 illustrate. 
 
 2. Colors, sounds, temperatures, pressures, spaces, times, 
 and so forth, are connected with one another in manifold ways; 
 and with them are associated moods of mind, feelings, and voli- 
 tions. Out of this fabric, that which is relatively more fixed 
 and permanent stands prominently forth, engraves itself in the 
 memory, and expresses itself in language. Relatively greater 
 permanency exhibit, first, certain complexes of colors, sounds, 
 pressures, and so forth, connected in time and space, which 
 therefore receive special names, and are designated bodies. 
 Absolutely permanent such complexes are not. 
 
 My table is now brightly, now dimly lighted. Its tempera- 
 ture varies. It may receive an ink stain. One of its legs may 
 be broken. It may be repaired, polished, and replaced part for 
 part. But for me, amid all its changes, it remains the table at 
 which I daily write. 
 
 My friend may put on a different coat. His countenance 
 may assume a serious or a cheerful expression. His complex- 
 ion, under the effects of light or emotion, may change. His 
 shape may be altered by motion, or be definitely changed. Yet 
 the number of the permanent features presented, compared 
 with the number of the gradual alterations, is always so great, 
 that the latter may be overlooked. It is the same friend with 
 whom I take my daily walk. 
 
 My coat may receive a stain, a tear. My very manner of ex- 
 pression shows that we are concerned here with a sum-total of 
 permanency, to which the new element is added and from which 
 that which is lacking is subsequently taken away. 
 
 Our greater intimacy with this sum-total of permanency, 
 and its preponderance as contrasted with the changeable, 
 impel us to the partly instinctive, partly voluntary and con- 
 scious economy of mental representation and designation, as 
 expressed in ordinary thought and speech. That which is 
 perceptually represented in a single image receives a single 
 designation, a single name.
 
 ANALYSIS OF SENSATIONS 599 
 
 As relatively permanent, there is exhibited, further, that 
 complex of memories, moods, and feelings, joined to a particu- 
 lar body (the human body), which is denominated the "I" or 
 " Ego." I may be engaged upon this or that subject, I may be 
 quiet or animated, excited or ill-humored. Yet, pathological 
 cases apart, enough durable features remain to identify the ego. 
 Of course, the ego also is only of relative permanency. 
 
 After a first survey has been obtained, by the formation of 
 the substance-concepts " body" and "ego" (matter .and soul), 
 the will is impelled to a more exact examination of the changes 
 that take place in these relatively permanent existences. The 
 changeable features of bodies and of the ego, in fact, are exactly 
 what moves the will to this examination. Here the component 
 parts of the complex are first exhibited as its properties. A fruit 
 is sweet; but it can also be bitter. Also, other fruits may be 
 sweet. The red color we are seeking is found in many bodies. 
 The neighborhood of some bodies is pleasant; that of others, 
 unpleasant. Thus, gradually, different complexes are found to 
 be made up of common elements. The visible, the audible, the 
 tangible, are separated from bodies. The visible is analysed 
 into colors and into form. In the manifoldness of the colors, 
 again, though here fewer in number, other component parts are 
 discerned such as the primary colors, and so forth. The 
 complexes are disintegrated into elements. 
 
 3. The useful habit of designating such relatively perma- 
 nent compounds by single names, and of apprehending them 
 by single thoughts, without going to the trouble each time of an 
 analysis of their component parts, is apt to come into strange 
 conflict with the tendency to isolate the component parts. The 
 vague image which we have of a given permanent complex, be- 
 ing an image which does not perceptibly change when one or 
 another of the component parts is taken away, gradually estab- 
 lishes itself as something which exists by itself. Inasmuch as it 
 is possible to take away singly every constituent part without 
 destroying the capacity of the image to stand for the totality 
 and of being recognised again, it is imagined that it is possible
 
 6oo ERNST MACH 
 
 to subtract all the parts and to have something still remaining. 
 Thus arises the monstrous notion of a thing in itself, unknow- 
 able and different from its " phenomenal" existence. 
 
 Thing, body, matter, are nothing apart from their complexes 
 of colors, sounds and so forth nothing apart from their so- 
 called attributes. That Protean, supposititious problem, which 
 springs up so much in philosophy, of a single thing with many 
 attributes, arises wholly from a mistaking of the fact, that 
 summary comprehension and precise analysis, although both 
 are provisionally justifiable and for many purposes profitable, 
 cannot and must not be carried on simultaneously. A body 
 is one and unchangeable only so long as it is unnecessary to 
 consider its details. Thus both the earth and a billiard-ball 
 are spheres, if the purpose in hand permits our neglecting de- 
 viations from the spherical form, and great precision is not 
 necessary. But when we are obliged to carry on investigations 
 in orography or microscopy, both bodies cease to be spheres. 
 
 4. Man possesses, in its highest form, the power of con- 
 sciously and arbitrarily determining his point of view. He can 
 at one time disregard the most salient features of an object, 
 and immediately thereafter give attention to its smallest de- 
 tails ; now consider a stationary current, without a thought of its 
 contents, and then measure the width of a Fraunhofer line 
 in the spectrum ; he can rise at will to the most general abstrac- 
 tions or bury himself in the minutest particulars. The animal 
 possesses this capacity in a far less degree. It does not assume 
 a point of view, but is usually forced to it. The babe who does 
 not know its father with his hat on, the dog that is perplexed at 
 the new coat of its master, have both succumbed in this con- 
 flict of points of view. Who has not been worsted in similar 
 plights? Even the man of philosophy at times succumbs, as 
 the grotesque problem, above referred to, shows. 
 
 In this last case, the circumstances appear to furnish a real 
 ground for justification. Colors, sounds, and the odors of bod- 
 ies are evanescent. But the tangible part, as a sort of constant 
 durable nucleus, not readily susceptible of annihilation, re-
 
 ANALYSIS OF SENSATIONS 601 
 
 mains behind; appearing as the vehicle of the more fugitive 
 properties annexed to it. Habit, thus, keeps our thought firmly 
 attached to this central nucleus, even where the knowledge 
 exists that seeing, hearing, smelling, and touching are inti- 
 mately akin in character. A further consideration is, that ow- 
 ing to the singularly extensive development of mechanical 
 physics a kind of higher reality is ascribed to space and time 
 than to colors, sounds, and odors; agreeably to which, the tem- 
 poral and spatial links of colors, sounds, and odors appear to be 
 more real than the colors, sounds, and odors themselves. The 
 physiology of the senses, however, demonstrates, that spaces 
 and times may just as appropriately be called sensations as 
 colors and sounds. 
 
 5. The ego, and the relation of bodies to the ego, give rise to 
 similar pseudo-problems, the character of which may be briefly 
 indicated as follows: 
 
 Let those complexes of colors, sounds, and so forth, com- 
 monly called bodies, be designated, for the sake of simplicity, 
 by A B C . . . ; the complex, known as our own body, which 
 constitutes a part of the former, may be called K L M . . . ; 
 the complex composed of volitions, memory-images, and the 
 rest, we shall represent by a /3 7 . . . Usually, now, the com- 
 plex a/37 K L M . . ., as making up the ego, is opposed 
 to the. complex A B C . . ., as making up the world of sub- 
 stance; sometimes, also, a /3 7 . . . is viewed as ego, and KLM 
 . . . A B C ... as world of substance. Now, at first blush, 
 ABC... appears independent of the ego, and opposed to it 
 as a separate existence. But this independence is only relative, 
 and gives way upon closer inspection. Much, it is true, may 
 change in the complex a /3 7 ... without a perceptible change 
 being induced in A B C . . . ; and vice versa. But many changes 
 in a/37 ... do pass, by way of changes in K L M . . ., 
 toABC...', and vice versa. (As, for example, when power- 
 ful ideas burst forth into acts, or our environment induces 
 noticeable changes in our body.) At the same time the group 
 KLM... appears to be more intimately connected with
 
 602 ERNST MACH 
 
 afiy . . . and with ABC..., than the latter do with one 
 another; relations which find their expression in common 
 thought and speech. 
 
 Precisely viewed, however, it appears that the group ABC 
 ... is always codetermined by K L M. A cube of wood when 
 seen close at hand, looks large; when seen at a distance, small; 
 it looks different with the right eye from what it does with the 
 left; sometimes it appears double; with closed eyes it is invis- 
 ible. The properties of the same body, therefore, appear modi- 
 fied by our own body; they appear conditioned by it. But 
 where, now, is that same body, which to the appearance is so 
 different ? All that can be said is, that with different K L M 
 different ABC... are associated. 
 
 We see an object having a point S. If we touch 5, that is, 
 bring it into connexion with our body, we receive a prick. We 
 can see S, without feeling the prick. But as soon as we feel the 
 prick we find S. The visible point, therefore, is a permanent 
 fact or nucleus, to which the prick is annexed, according to cir- 
 cumstances, as something accidental. From the frequency of 
 such occurrences we ultimately accustom ourselves to regard 
 all properties of bodies as "effects" proceeding from perman- 
 ent nuclei and conveyed to the ego through the medium of 
 the body; which effects we call sensations. By this operation, 
 however, our imagined nuclei are deprived of their entire sen- 
 sory contents, and converted into mere mental symbols. The 
 assertion, then, is correct that the world consists only of our 
 sensations. In which case we have knowledge only of sensa- 
 tions, and the assumption of the nuclei referred to, or of a re- 
 ciprocal action between them, from which sensations proceed, 
 turns out to be quite idle and superfluous. Such a view can 
 only suit with a half-hearted realism or a half-hearted philo- 
 sophical criticism. 
 
 6. Ordinarily the complex a jBy . . . K L M . .. is contrasted 
 as ego with the complex ABC. Those elements only of A B C 
 . . . that more strongly alter a fi y . . ., as a prick, a pain, are 
 wont to be comprised in the ego. Afterwards, however, through
 
 ANALYSIS OF SENSATIONS 603 
 
 observations of the kind just referred to, it appears that the 
 right to annex A B C ... to the ego nowhere ceases. In con- 
 formity with this view the ego can be so extended as ultimately 
 to embrace the entire world. The ego is not sharply marked off, 
 its limits are very indefinite and arbitrarily displaceable. Only 
 by failing to observe this fact, and by unconsciously narrowing 
 those limits, while at the same time we enlarge them, arise, in 
 the conflict of points of view, the metaphysical difficulties met 
 with in this connection. 
 
 As soon as we have perceived that the supposed unities 
 "body" and "ego" are only makeshifts, designed for provis- 
 ional survey and for certain practical ends (so that we may 
 take hold of bodies, protect ourselves against pain, and so forth), 
 we find ourselves obliged, in many profound scientific investi- 
 gations, to abandon them as insufficient and inappropriate. 
 The antithesis of ego and world, sensation (phenomenon) and 
 thing, then vanishes, and we have simply to deal with the con- 
 nexion of the elements a/3y...ABC...KLM...., 
 of which this antithesis was only a partially appropriate and 
 imperfect expression. This connexion is nothing more nor less 
 than the combination of the above-mentioned elements with 
 other similar elements (time and space). Science has simply to 
 accept this connexion, and to set itself aright (get its bearings) 
 in the intellectual environment which is thereby furnished, 
 without attempting to explain its existence. 
 
 On a superficial examination the complex a /3 7 . . . appears 
 to be made up of much more evanescent elements than ABC 
 . . . and K L M . . . in which last the elements seem to be 
 connected with greater stability and in a more permanent man- 
 ner (being joined to solid nuclei as it were). Although on closer 
 inspection the elements of all complexes prove to be homogene- 
 ous, yet in spite of the knowledge of this fact, the early notion 
 of an antithesis of body and spirit easily regains the ascendancy 
 in the mind. The philosophical spiritualist is often sensible of 
 the difficulty of imparting the needed solidity to his mind- 
 created world of bodies ; the materialist is at a loss when required 
 to endow the world of matter with sensation. The monistic
 
 604 ERNST MACH 
 
 point of view, which artificial reflexion has evolved, is easily 
 clouded by our older and more powerful instinctive notions. 
 
 7. The difficulty referred to is particularly felt in the follow- 
 ing case. In the complex A B C . . ., which we have called the 
 world of matter, we find as parts, not only our own body KLM 
 . . ., but also the bodies of other persons (or animals) K ' L' M' 
 . . ., K" L" M" . . ., to which, by analogy, we imagine other 
 a' &' 7' . . . , a " &" 7" . . ., annexed, similar to a fi y . . .So 
 long as we deal with K' L' M ' . . ., we find ourselves in a 
 thoroughly familiar province at every point sensorially acces- 
 sible to us. When, however, we inquire after the sensations or 
 feelings appurtenant to the body K' L' M' . . ., we no longer 
 find the elements we seek in the province of sense: we add them 
 in thought. Not only is the domain which we now enter far less 
 familiar to us, but the transition into it is also relatively un- 
 safe. We have the feeling as if we were plunging into an abyss. 
 Persons who adopt this method only, will never thoroughly rid 
 themselves of this sense of insecurity, which is a frequent source 
 of illusive problems. 
 
 But we are not restricted to this course. Let us consider, 
 first, the reciprocal relations of the elements of the complex 
 ABC . . ., without regarding KLM... (our body). All 
 physical investigations are of this sort. A white bullet falls 
 upon a bell; a sound is heard. The bullet turns yellow before a 
 sodium lamp, red before a lithium lamp. Here the elements 
 (ABC. . .) appear to be connected only with one another and 
 to be independent of our body (KLM . . .). But if we take 
 santonine, the bullet again turns yellow. If we press one eye 
 to the side, we see two bullets. If we close our eyes entirely, 
 we see none at all. If we sever the auditory nerve, no sound is 
 heard. The elements ABC..., therefore, are not only con- 
 nected among one another, but also with KLM. To this ex- 
 tent, and to this extent only, do we call ABC. . . sensations, 
 and regard A B C as belonging to the ego. In this way, accord- 
 ingly, we do not find the gap between bodies and sensations 
 above described, between what is without and what is within,
 
 ANALYSIS OF SENSATIONS 605 
 
 between the material world and the spiritual world. 1 All ele- 
 ments A B C . . ., K L M . . . constitute a single coherent 
 mass only, in which, when any one element is disturbed, all is 
 put in motion; except that a disturbance in K L M . . . has 
 a more extensive and profound action than in A B C. A magnet 
 in our neighborhood disturbs the particles of iron near it; a 
 falling boulder shakes the earth; but the severing of a nerve 
 sets in motion the whole system of elements. 
 
 I 
 
 8. That traditional gulf between physical and psychological 
 research, accordingly, exists only for the habitual stereotyped 
 method of observation. A color is a physical object so long as 
 we consider its dependence upon its luminous source, upon other 
 colors, upon heat, upon space, and so forth. Regarding, how- 
 ever, its dependence upon the retina (the elements K L M. . . ) 
 it becomes a psychological object, a sensation. Not the sub- 
 ject, but the direction of our investigation, is different in the 
 two domains. 
 
 Both in reasoning from the observation of the bodies of other 
 men or animals, to the sensations which they possess, as well 
 as in investigating the influence of our own body upon our own 
 sensations, we must complete observed facts by analogy. This 
 is accomplished with much greater readiness and certainty, 
 when it relates, say, only to nervous processes, which cannot be 
 fully observed in our own bodies that is, when it is carried 
 out in the more familiar physical domain than when it is 
 made in connexion with psychical processes. Otherwise there 
 is no essential difference. 
 
 10. Reference has already been made to the different char- 
 acter of the groups of elements designated by A B C . . . and 
 a/3y. As a matter of fact, when we see a green tree before us, 
 or remember a green tree, that is, represent a green tree to our- 
 selves, we are perfectly aware of the difference of the two cases. 
 The represented tree has a much less determinate, a much more 
 
 1 Compare my Grundlinien der Lehre von den Bewegungsempfindungen, Leipsic, 
 Engelmann, 1875, p. 54.
 
 6o6 ERNST MACH 
 
 changeable form; its green is much paler and more evanescent; 
 and, what is of especial note, it is plainly situated in a different 
 domain. A. movement that we propose to execute is never more 
 than a represented movement, and appears in a different sphere 
 from that of the executed movement, which always takes place 
 when the image is vivid enough. The statement that the ele- 
 ments A and a appear in different spheres, means, if we go to 
 the bottom of it, simply this, that these elements are united 
 with different other elements. Thus far, therefore, the funda- 
 mental constituents of ABC. . ., afty . . . would seem to be 
 the same (colors, sounds, spaces, times, motor sensations. . . ), 
 and only the character of their connexion different. 
 
 Ordinarily pleasure and pain are regarded as different from 
 sensations. Yet not only tactile sensations, but all other kinds 
 of sensations, may pass gradually into pleasure and pain. Plea- 
 sure and pain also may be justly termed sensations. Only they 
 are not so well analysed and so familiar as the common sensa- 
 tions. In fact, sensations of pleasure and pain, however faint 
 they may be, really, make up the contents of all so-called emo- 
 tions. Thus, perceptions, ideas, volition, and emotion, in 
 short the whole inner and outer world, are composed of a small 
 number of homogeneous elements connected in relations of vary- 
 ing evanescence or permanence. Usually, these elements are 
 called sensations. But as vestiges of a one-sided theory inhere 
 in that term, we prefer to speak simply of elements, as we have 
 already done. The aim of all research is to ascertain the mode 
 of connexion of these elements. 1 
 
 ii. That in this complex of elements, which fundamentally 
 is one, the boundaries of bodies and of the ego do not admit of 
 being established in a manner definite and sufficient for all cases, 
 has already been remarked. The comprehending of the elements 
 that are most intimately connected with pleasure and pain, 
 under one ideal mental-economical unity, the ego, is a work of 
 the highest significance for the intellect in the functions which 
 
 1 Compare the note at the conclusion of my treatise, Die Geschichte und die 
 Wurzel des Satzes der Erhaltung der Arbeit, Prague, CaK'e, 1872.
 
 ANALYSIS OF SENSATIONS 607 
 
 it performs for the pain-avoiding, pleasure-seeking will. The 
 delimitation of the ego, therefore, is instinctively effected, 
 is rendered familiar, and possibly becomes fixed through hered- 
 ity. Owing to their high practical value, not only for the in- 
 dividual, but for the entire species, the composites "ego" and 
 "body" assert instinctively their claims, and operate with all 
 the power of natural elements. In special cases, however, in 
 which practical ends are not concerned, but where knowledge 
 is an object in itself, the delimitation in question may prove to 
 be insufficient, obstructive, and untenable. 1 
 
 The primary fact is not the I, the ego, but the elements (sen- 
 sations) . The elements constitute the I. That I have the sensa- 
 tion green, signifies that the element green occurs in a given 
 complex of other elements (sensations, memories). When / 
 cease to have the sensation green, when I die, then the ele- 
 ments no longer occur in their ordinary, familiar way of asso- 
 ciation. That is all. Only an ideal mental-economical unity, 
 not a real unity, has ceased to exist. 
 
 If a knowledge of the connexion of the elements (sensations) 
 does not suffice us, and we ask, Who possesses this connexion 
 of sensations, Who experiences the sensations ? then we have 
 succumbed to the habit of subsuming every element (every 
 sensation) under some unanalysed complex, and we are fall- 
 ing back imperceptibly upon an older, lower and more limited 
 point of view. 
 
 The so-called unity of consciousness is not an argument in 
 point. Since the apparent antithesis of real world and perceived 
 world is due entirely to our mode of view, and no actual gulf 
 
 1 Similarly, esprit de corps, class bias, national pride, and even the narrowest 
 minded local patriotism may have a high value, for certain purposes. But such 
 attitudes will not be shared by the broad-minded inquirer, at least not in mo- 
 ments of research. All such egoistic views are adequate only for practical pur- 
 poses. Of course, even the inquirer may succumb to habit. Trifling pedantries 
 and nonsensical discussions, the cunning appropriation of others' thoughts, with 
 perfidious silence as to the sources, the metaphorical dysphagia suffered when 
 recognition must be given, and the crooked illumination of others' performances 
 when this is done, abundantly show that the scientist and scholar have also the 
 battle of existence to fight, that the ways of science still lead to the mouth, and 
 that the pure quest of knowledge in our present social conditions is still an ideal.
 
 608 ERNST MACH 
 
 exists between them, a rich and variously interconnected con- 
 tent of consciousness is in no respect more difficult to under- 
 stand than a rich and diversified interconnexion of the world. 
 
 If we regard the ego as a real unity, we become involved in 
 the following dilemma : either we must set over against the ego 
 a world of unknowable entities (which would be quite idle and 
 purposeless), or we must regard the whole world, the egos of 
 other people included, as comprised in our own ego (a proposi- 
 tion to which it is difficult to yield serious assent). 
 
 But if we take the eeo simply as a practical unity, put to- 
 gether for purposes of provisional survey, or simply as a more 
 strongly coherent group of elements, less strongly connected 
 with other groups of this kind, questions like those above dis- 
 cussed will not arise and research will have an unobstructed 
 future. 
 
 In his philosophical notes Lichtenberg says: "We become 
 conscious of certain percepts that are not dependent upon us; 
 of others that we at least think are dependent upon us. Where 
 is the border-line? We know only the existence of our sensa- 
 tions, percepts, and thoughts. We should say, // thinks, just 
 as we say, it lightens. It is going too far to say cogito, if we 
 translate cogito by / think. The assumption, or postulation, of 
 the ego is a mere practical necessity." Though the method by 
 which Lichtenberg arrived at this result is somewhat different 
 from ours, we must nevertheless give our full assent to his con- 
 clusion. 
 
 12. Bodies do not produce sensations, but complexes of 
 sensations (complexes of elements) make up bodies. If, to the 
 physicist, bodies appear the real, abiding existences, whilst 
 sensations are regarded merely as their envanescent, transitory 
 show, the physicist forgets, in the assumption of such a view, 
 that all bodies are but thought-symbols for complexes of sens- 
 ations (complexes of elements). Here, too, the elements form 
 the real, immediate, and ultimate foundation, which it is the 
 task of physiological research to investigate. By the recogni- 
 tion of this fact, many points of psychology and physics as- 
 
 i
 
 ANALYSIS OF SENSATIONS 609 
 
 sume more distinct and more economical forms, and many 
 spurious problems are disposed of. 
 
 For us, therefore, the world does not consist of mysterious 
 entities, which by their interaction with another, equally mys- 
 terious entity, the ego, produce sensations, which alone are 
 accessible. For us, colors, sounds, spaces, times, . . . are the 
 ultimate elements, whose given connexion it is our business to 
 investigate. In this investigation we must not allow ourselves 
 to be impeded by such intellectual abridgments and delimita- 
 tions, as body, ego, matter, mind, etc., which have been formed 
 for special, practical purposes and with wholly provisional and 
 limited ends in view. On the contrary, the fittest forms of 
 thought must be created in and by that research itself, just as is 
 done in every special science. In place of the traditional, in- 
 stinctive ways of thought, a freer, fresher view, conforming to 
 developed experience, must be substituted. 
 
 13. Science always takes its origin in the adaptation of 
 thought to some definite field of experience. The results of the 
 adaptation are thought-elements, which are able to represent 
 the field. The outcome, of course, is different, according to the 
 character and extent of the province surveyed. If the province 
 of experience in question is enlarged, or if several provinces 
 heretofore disconnected are united, the traditional, familiar 
 thought-elements no longer suffice for the extended province. 
 In the struggle of acquired habit with the effort after adapta- 
 tion, problems arise, which disappear when the adaptation is 
 perfected, to make room for others which have arisen in the 
 interim. 
 
 To the physicist, qua physicist, the idea of "body" is pro- 
 ductive of a real facilitation of view, and is not the cause of 
 disturbance. So, also, the person with purely practical aims, is 
 materially assisted by the idea of the / or ego. For, unques- 
 tionably, every form of thought that has been designedly or 
 undesignedly constructed for a given purpose, possesses for that 
 purpose a permanent value. When, however, research in phy- 
 sics and in psychology meets, the ideas held in the one domain
 
 610 ERNST MACH 
 
 prove to be untenable in the other. From the attempt at mu- 
 tual adaptation arise the various atomic and monadic theories 
 which, however, never attain their end. If we regard sens- 
 ations, in the sense above denned, as the elements of the world, 
 the problems referred to are practically disposed of, and the 
 first and most important adaptation effected. This fundamen- 
 tal view (without any pretension to being a philosophy for all 
 eternity) can at present be adhered to in all provinces of expe- 
 rience; it is consequently the one that accommodates itself 
 with the least expenditure of energy, that is, more economically 
 than any other, to the present temporary collective state of know- 
 ledge. Furthermore, in the consciousness of its purely econom- 
 ical office, this fundamental view is eminently tolerant. It does 
 not obtrude itself into provinces in which the current concep- 
 tions are still adequate. It is ever ready, upon subsequent 
 extensions of the domain of experience, to yield the field to a 
 better conception. 
 
 The philosophical point of view of the average man if that 
 term may be applied to the nai've realism of the ordinary indi- 
 vidual has a claim to the highest consideration. It has arisen 
 in the process of immeasurable time without the conscious as- 
 sistance of man. It is a product of nature, and is preserved and 
 sustained by nature. Everything that philosophy has accom- 
 plished the biological value of every advance, nay, of every 
 error, admitted is, as compared with it, but an insignificant 
 and ephemeral product of art. The fact is, every thinker, every 
 philosopher, the moment he is forced to abandon his narrow 
 intellectual province by practical necessity, immediately returns 
 to the universal point of view held by all men in common. 
 
 To discredit this point of view is not then the purpose of the 
 foregoing "introductory remarks." The task which we have 
 set ourselves is simply to show why and to what purpose for the 
 greatest portion of life we hold it, and why and for what purpose 
 we are provisorily obliged to abandon it. No point of view has 
 absolute, permanent validity. Each has importance only for 
 some given end. 1 
 
 1 A kindred view will be found in Avenarius, Kritik der reinen Erfal:rung.
 
 ANALYSIS OF SENSATIONS 611 
 
 THE SPACE-SENSATIONS 
 
 1 . THE tree with its hard, rough grey trunk, its numberless 
 branches swayed by the wind, its smooth soft, shining leaves, 
 appears to us at first a single, indivisible whole. In like manner, 
 we regard the sweet, round, yellow fruit, the warm, bright fire, 
 with its manifold moving tongues, as a single thing. One name 
 designates the whole, one word draws forth from the depths of 
 oblivion all associated memories, as if they were strung upon 
 a single thread. 
 
 The reflexion of the tree, the fruit, or the fire in a mirror is 
 visible, but not tangible. When we turn our glance away or 
 close our eyes, we can touch the tree, taste the fruit, feel the 
 fire, but we cannot see them. Thus the apparently indivisible 
 thing is separated into parts, which are not only connected with 
 one another but are also joined to other conditions. The visible 
 is separable from the tangible, from that which may be tasted, 
 
 The visible also appears at first sight to be a single thing. 
 But we may see a round, yellow fruit together with a yellow, 
 star-shaped blossom. A second fruit is just as round as the first, 
 but is green or red. Two things maybe alike in color but unlike 
 in form ; they may be different in colour but like in form. Thus 
 sensations of sight are separable into color-sensations and space- 
 sensations. 
 
 2. Color-sensation, into the details of which we shall not 
 enter here, is essentially a sensation of favorable or unfavor- 
 able chemical conditions of life. In the process of adaptation to 
 these conditions, color-sensation may have been developed and 
 modified. Light introduces organic life. The green chlorophyll 
 and the (complementary) red haemoglobin play a prominent 
 part in the chemical processes of the plant-body and in the con- 
 trary processes of the animal body. The two substances pre- 
 sent themselves to us in the most varied modifications of tint. 
 The discovery of the visual purple, observations in photogra-
 
 6i2 ERNST MACH 
 
 phy and photochemistry render the conception of processes of 
 sight as chemical processes permissible. The r61e which color 
 plays in analytical chemistry, in spectrum-analysis, in crystal- 
 lography, is well known. It suggests a new conception for the 
 so-called vibrations of light, according to which they are re- 
 garded, not as mechanical, but as chemical vibrations, as suc- 
 cessive union and separation, as an oscillatory process of the 
 same sort that takes place, though only in one direction, in 
 photo-chemical phenomena. This conception, which is sub- 
 stantially supported by recent investigations in abnormal dis- 
 persion, accords with the electro-magnetic theory of light. In 
 the case of electrolysis, in fact, chemistry yields the most in- 
 telligible conception of the electric current, regarding the two 
 components of the electrolyte as passing through each other in 
 opposite directions. It is likely, therefore, that in a future 
 theory of colors, many biologico-psychological and chemico- 
 physical threads will be united. 
 
 3. Adaptation to the chemical conditions of life which mani- 
 fest themselves in color, renders locomotion necessary to a far 
 greater extent than adaptation to those which manifest them- 
 selves through taste and smell. At least this is so in the case of 
 man, concerning whom alone we are able to judge with immed- 
 iacy and certainty. The close association of space-sensation (a 
 mechanical factor) with color-sensation (a chemical factor) is 
 herewith rendered intelligible. We shall now proceed to the 
 analysis of space-sensations. 
 
 4. In examining two figures which are alike but differently 
 colored (for example, two letters of the same size and shape, but 
 
 of different colors), we recognise their sameness 
 
 NVH I of form at the first glance, in spite of the differ- 
 ftj ence of color-sensation. The sight-perceptions, 
 therefore, must contain some like sensation- 
 components. These are the space-sensations 
 which are the same in the two cases.
 
 ANALYSIS OF SENSATIONS 613 
 
 5. We will now investigate the character of the space-sens- 
 ations that physiologically condition the recognition of a fig- 
 ure. First, it is clear that this recognition is not the result 
 of geometrical considerations which are a matter, not of 
 sensation, but of intellect. On the contrary, the space-sensa- 
 tions in question serve as the starting-point and foundation 
 of all geometry. Two figures may be geometrically congruent, 
 but physiologically quite different. . . . 
 
 6. In what, now, does the essential nature of optical similar- 
 ity, as contrasted with geometrical similarity, consist? In geo- 
 metrically similar figures, all homologous distances are propor- 
 tional. But this is an affair of the intellect, not of sensation. 
 If we place beside a triangle with the sides a, b, c, a triangle 
 with the sides 20, 2&, 2C, we do not recognise the simple rela- 
 tion of the two immediately, but intellectually, by measure- 
 ment. If the similiarity is to become optically perceptible, the 
 proper position must be added. That a simple intellectual re- 
 lationship of two objects does not necessarily condition a sim- 
 ilarity of sensation, may be perceived by comparing two tri- 
 angles having respectively the sides a, b, c, and a+m, b+m, 
 c+m. The two triangles do not look at all alike. Similarly all 
 conic sections do not look alike, although all stand in a simple 
 geometric relation to each other; still less do curves of the third 
 order exhibit optical similiarity; etc. 
 
 7. The geometrical similarity of two figures is determined 
 by all their homologous lines being proportional or by all their 
 homologous angles being equal. 
 
 But to appear optically similar 
 the figures must also be similarly 
 situated, that is all their homo- 
 logous lines must be parallel or, F 
 as we prefer to say, have the 
 
 same direction (Fig. 2). By likeness of direction, accordingly, 
 are determined like space-sensations, and these are character- 
 istic of the physiologico-optical similarity of figures. 
 
 We may obtain an idea of the physiological significance of
 
 614 ERNST MACH 
 
 the direction of a given straight line or curve-element, by the 
 following reflexion. Let y = f (x) be the equation of a plane 
 curve. We can read at a glance the course of the values of dy/dx 
 on the curve, for they are determined by its slope; and the eye 
 gives us, likewise, qualitative information concerning the values 
 of d 2 y/dx 2 , for they are characterised by the curvature. The 
 question naturally presents itself why can we not arrive at as 
 immediate conclusions concerning the values d 3 y/dx 3 , d*y/dx 4 , 
 etc. The answer is easy. What we see are not the differential 
 coefficients, which are an intellectual affair, but only the direc- 
 tion of the curve-elements, and the declination of the direction 
 of one curve-element from that of another. 
 
 In fine, since we are immediately cognisant of the similarity 
 of figures lying in similar positions, and are also able to distin- 
 guish without ado the special case of congruity, therefore our 
 space-sensations yield us information concerning likeness or un- 
 likeness of directions and equality or inequality of spatial dimen- 
 sions. 
 
 8. It is extremely probable that sensations of space are pro- 
 duced by the motor apparatus of the eye. Without entering 
 into particulars, we may observe, first, that the whole appara- 
 tus of the eye, and especially the motor apparatus, is symmet- 
 rical with respect to the median plane of the head. Hence, 
 symmetrical movements of looking will determine like or ap- 
 proximately like space-sensations. Children constantly con- 
 found the letters b and d, as p and q. Adults, too, do not 
 readily notice a change from left to right unless some special 
 points of apprehension for sense or intellect render it percept- 
 ible. The symmetry of the motor apparatus of the eye is very 
 perfect. The like excitation of its symmetrical organs would, 
 by itself scarcely account for the distinction of right and left. 
 But the whole human body, especially the brain, is affected 
 with a slight asymmetry, which leads, for example, to the pre- 
 ference of one (generally the right) hand, in motor functions. 
 And this leads, again, to a further and better development of 
 the motor functions of the right side, and to a modification of
 
 ANALYSIS OF SENSATIONS 615 
 
 the attendant sensations. After the space-sensations of the eye 
 have become associated, through writing, with the motor func- 
 tions of the right hand, a confusion of those vertically symmet- 
 rical figures with which the art and habit of writing are con- 
 cerned no longer ensues. This association may, indeed, become 
 so strong that remembrance follows only the accustomed tracks, 
 and we read, for example, the reflexion of written or printed 
 words in a mirror only with the greatest difficulty. The con- 
 fusion of right and left still occurs, however, with regard to 
 figures which have no motor, but only a purely optical (for ex- 
 ample, ornamental) interest. A noticeable difference between 
 right and left must be felt, moreover, by animals, as in many 
 predicaments they have no other means of finding their way. 
 The similarity of sensations connected with symmetrical motor 
 functions is easily remarked by the attentive observer. If, for 
 example, supposing my right hand to be employed, I grasp a 
 micrometer-screw or a key with my left hand, I am certain (un- 
 less I reflect beforehand) to turn it in the wrong direction, - 
 that is, I always perform the movement which is symmetrical to 
 the usual movement, confusing the two because of the similar- 
 ity of the sensation. The observations of Heidenhain regard- 
 ing the reflected writing of persons hypnotised on one side 
 should also be cited in this connexion. 
 
 With looking upwards and looking downwards, fundament- 
 ally different space-sensations are associated, as ordinary ob- 
 servations will show. This is, moreover, comprehensible, since 
 the motor apparatus of the eye is asymmetrical with respect to 
 a horizontal plane. The direction of gravity is so very decisive 
 and important for the motor apparatus of the rest of the body 
 that the same factor has assuredly also found its expression in 
 the apparatus of the eye, which serves the rest. It is well known 
 that the symmetry of a landscape and of its reflexion in water is 
 not felt. The portrait of a familiar personage, when turned 
 upside down, is strange and puzzling to a person who does not 
 recognise it intellectually. If we place ourselves behind the 
 head of a person lying upon a couch and unreflectingly give 
 ourselves up to the impression which the face makes upon us,
 
 616 ERNST MACH 
 
 we shall find that it is altogether strange, especially when the 
 person speaks. The letters b and p, and d and q, are not con- 
 fused by children. 
 
 Our previous remarks concerning symmetry, similarity, and 
 the rest, naturally apply not only to plane figures, but also to 
 those in space. Hence, we have yet a remark to add concern- 
 ing the sensation of space-depth. Looking at objects afar off 
 and looking at objects near at hand determine different sensa- 
 tions. These sensations must not be confused, because of the 
 supreme importance of the difference between near and far, 
 both for animals and human beings. They cannot be confused 
 because the motor apparatus is asymmetrical with respect to a 
 plane perpendicular to the direction from front to rear. The 
 observation that the bust of a familiar personage cannot be 
 replaced by the mould in which the bust is cast is quite 
 analogous to the observations consequent upon the inversion 
 of objects. 
 
 9. If equal distances and like directions excite like space-sens- 
 ations, and directions symmetrical with respect to the median 
 plane of the head excite similar space-sensations, the explana- 
 tion of the above-cited facts is not far to seek. The straight 
 line has, in all its elements, the same direction, and everywhere 
 excites the same space-sensations. Herein consists its aesthetic 
 value. Moreover, straight lines which lie in the median plane 
 or are perpendicular to it are brought into special relief by the 
 circumstance that, through this position of symmetry, they 
 occupy a like position to the two halves of the visual apparatus. 
 Every other position of the straight line is felt as awryness, or 
 as a deviation from the position of symmetry. 
 
 The repetition of the same space-figure in the same position 
 conditions a repetition of the same space-sensation. All lines 
 connecting prominent (noticeable) homologous points have the 
 same direction and excite the same sensation. Likewise when 
 merely geometrically similar figures are placed side by side in 
 the same positions, this relation holds. The sameness of the 
 dimensions alone is absent. But when the positions are dis-
 
 ANALYSIS OF SENSATIONS . 617 
 
 turbed, this relation, and with it, the impression of unity 
 the aesthetic impression are also disturbed. 
 
 In a figure symmetrical with respect to the median plane, 
 similar space-sensations corresponding to the symmetrical di- 
 rections take the place of the identical space-sensations. The 
 right half of the figure stands in the same relation to the right 
 half of the visual apparatus as the left half of the figure does to 
 the left half of the visual apparatus. If we alter the sameness 
 of the dimensions, the sensation of symmetrical similarity is 
 still felt. An oblique position of the plane of symmetry dis- 
 turbs the whole effect. 
 
 If we turn a figure through 180, contrasting it with itself in 
 its original position, centric symmetry is produced. That is, if 
 two pairs of homologous points be connected, the connecting 
 lines will cut each other at a point 0, through which, as their 
 point of bisection, all lines connecting homologous points will 
 pass. Moreover, in the case of centric symmetry, all lines of 
 connexion between homologous points have the same direction, 
 a fact which produces an agreeable sensation. If the same- 
 ness of the dimensions is eliminated, there still remains, for 
 sensation, centrically symmetrical similarity. 
 
 Regularity appears to have no special physiological value, 
 in distinction from symmetry. The value of regularity prob- 
 ably lies rather in its manifold symmetry, which is perceptible 
 in more than one single position. 
 
 10. The correctness of these observations will be apparent 
 on glancing over the work of Owen Jones A Grammar of 
 Ornament (London, 1865). In almost every plate one finds 
 new and different kinds of symmetry as fresh testimony in 
 favor of the conceptions above advanced. The art of decora- 
 tion, which, like pure instrumental music, aims at no ulterior 
 end, but ministers only to pleasure in form (and color), is 
 the best source of material for our present studies. Writing 
 is governed by other considerations than that of beauty. 
 Nevertheless, we find among the twenty-four large Latin letters 
 ten which are vertically symmetrical (A, H, I, M, O, T, V,
 
 6i8 ERNST MACH 
 
 W, X, Y), five which are horizontally symmetrical (B, C, D, 
 E, K), three which are centrically symmetrical (N, S, Z), and 
 only six which are unsymmetrical (F, G, L, P, Q, R). 
 
 ii. It is to be remarked again that the geometrical and the 
 physiological properties of a figure in space are to be sharply 
 distinguished. The physiological properties are determined by 
 the geometrical properties coincidently with these, but are not 
 determined by these solely. On the other hand, physiological 
 properties very probably gave the first impulse to geometrical 
 investigations. The straight line doubtless attracted attention 
 not because of its being the shortest line between two points, 
 but because of its physiological simplicity. The plane likewise 
 possesses, in addition to its geometrical properties, a special 
 physiologico-optical (aesthetic) value, which claims notice for 
 it, as will be shown later on. The division of the plane and of 
 space by right angles has not only the advantage of producing 
 equal parts, but also an additional and special symmetry-value. 
 The circumstance that congruent and similar geometrical fig- 
 ures can be brought into positions where their relationship is 
 physiologically felt, led, no doubt, to an earlier investigation of 
 these kinds of geometrical relationship than of those that are 
 less noticeable, such as affinity, collineation, and others. With- 
 out the co-operation of sense-perception and understanding, a 
 scientific geometry is inconceivable. . . .
 
 CARL STUMPF 
 
 (1848- ) 
 
 Translated from the German* by 
 BENJAMIN RAND 
 
 19. THE DEGREES OF TONAL FUSION 
 
 i. What tonal fusion is and what it is not. 
 
 IT has already been mentioned in what precedes, that not 
 merely do simultaneous as contrasted with successive tones 
 enter into a special relation in sensation, which renders their 
 analysis difficult, but that also there are differences in this 
 respect among simultaneous tones, according to the numerical 
 ratio of their vibrations. We must now turn our attention to 
 this fact. I will first illustrate it by two extreme examples. 
 
 If two tones, the number of whose vibrations are related as 
 i :2, are simultaneously produced, they can be very imperfectly 
 discriminated in comparison with the case where, for example, 
 under otherwise precisely similar conditions, the ratio is as 40 177. 
 When I say, " imperfectly," I mean that the question is not as 
 to a difficulty, which might be overcome by increased attention 
 and practise, but as to an unchangeable characteristic of the ma- 
 terial of sensation, which persists even after all other obstacles to 
 an analysis have been removed, and which, moreover, after the 
 analysis is completed and the tones clearly recognized as two, 
 can first likewise be perceived in itself. In 40:77 the tones in the 
 sensation appear so to speak farther apart than in the case of 
 1:2, so that in the first case even the unmusical person is less, 
 or not at all, in danger of taking them for one; whereas on the 
 contrary, the octave tones cannot be kept distinct even by the 
 
 * From C. Stumpf's Tonpsychologie, Leipzig, 1890, Bd. n.
 
 620 CARL STUMPF 
 
 most delicate and practised ear, in the same degree as those of 
 the seventh, or of the unmusical relation 40:77. When the un- 
 practised designate simultaneous octave tones as one tone, 
 there is accordingly a double hindrance to analysis, namely: 
 one an imperfect practise, and the other in the tone itself; one, 
 which influences the judgment directly, and the other which 
 influences the sensation and in consequence of it the judgment. 
 
 What is most essential for the general characterisation of the 
 concept oi fusion, as we understand it, has been fairly exhausted 
 in what has been said, 1 and can be set forth still more clearly 
 only in the more inclusive range of a universal theory of rela- 
 tions, which is one of the most urgent needs of philosophical 
 science. We term fusion that relation of two contents, especially 
 sensation-contents, in which they form not a mere sum, but a 
 whole. The consequence of this relation is, that in its higher 
 degrees the total impression under otherwise like conditions 
 approaches more and more that of a single unified sensation, 
 and becomes more and more difficult to analyze. These results 
 can also be employed for a definition, and we can say: fusion is 
 that relation of two sensations as a consequence of which-, etc. 
 But in either way, the matter would remain an empty concept 
 for everyone to whom the phenomena in question, and espe- 
 cially the phenomena of tones, were foreign. The real truth of 
 the assertion, that sensations form a whole and approximate 
 more or less the impression of a single unified sensation, can 
 after all be learned only by means of examples. 
 
 Nevertheless, I remark, that the inclusion of the concept of 
 tonal fusion under that more general quality of simultaneous 
 as opposed to successive sensations, of which we have elsewhere 
 spoken, is not indispensable for what follows. The tonal fusion 
 will acquire for us more and more an interest of its own, inde- 
 pendent of the questions previously discussed ( 16 and 17); 
 and would also claim it even if a similar relation did not further 
 occur in the entire domain of sensations. It is far from being 
 an hypothesis devised for the solution of those difficulties. It is 
 a sensuous phenomena which was observed even before those 
 1 Cf. Stumpf's Tonpsychologie, p. 64 f.
 
 PSYCHOLOGY OF TONE 621 
 
 theoretical difficulties appeared within the intellectual horizon. 
 It suffices perfectly for the attainment of the concept here 
 necessary, to perceive and in perceiving to contrast, the dif- 
 ferences of the cases which exist already within the tonal do- 
 main, and which will be more accurately described in what fol- 
 lows. We must hear and compare tonal fusions, just as we must 
 hear and contrast tones, in order to know what a tone is. 
 
 Perhaps, however, it is expedient to preclude expressly some 
 misconceptions which the term fusion might occasion. It is 
 precisely one of those psychological expressions which have 
 been most misused, and to which the most impossible concep- 
 tions and entirely fictitious theories have become attached. 
 For this reason I have chosen it with reluctance, owing to the 
 lack of a safer and at the same time more specific word. 
 
 It is above all, therefore, not meant by fusion, that two simul- 
 taneous tones coalesce in a certain unity in consciousness only 
 by degrees, however quickly. Fusion signifies to us here not a 
 process, but a present relation. I would, therefore, rather use 
 "blend" (Schmelz), or "coalescence" (Schmalz), if this had 
 also not its objections. Such expressions also as " to separate " 
 (auseinandertreten) etc., are to be understood in this sense of 
 an already existent being; just as they are likewise used in the 
 sense of rest in the description of architectonic forms. 
 
 That fusion is not to be viewed as originating a third tonal 
 quality in addition to or instead of the other two, needs no 
 farther amplification after what has preceded ( 16 and 17). 
 
 Henceforth we must reject especially the metaphorical use of 
 spatial concepts. The naturalist is accustomed to think of 
 everything by the aid of spatial analogies; and psychologists 
 also, like Herbart and Beneke, who desire to approach the 
 exactness of natural science, employ them most extensively for 
 their psychological descriptions (such as, falling and rising, 
 overflowing, etc.). We are to disregard all such analogies as 
 might erroneously suggest them. Everything extended in space 
 is either outside, or identical with everything else. But simul- 
 taneous tones afford us an example of interpenetration ; and, 
 indeed, an interpenetration of a lower and higher degree. The
 
 622 CARL STUMPF 
 
 lack of all spatial perceptibility is wholly immaterial. It is, 
 however, wanting in the relation of quality and intensity. 
 Spatial perceptivity ceases moreover with psychical states as 
 such (cf. 100-104). The concepts here too must be adapted 
 to the observations. Only a contradiction is a priori an im- 
 possibility. But that the two tones are at the same time one, 
 is not affirmed. 
 
 In general the difficulties, which one still could, and will find, 
 in the concept of tonal fusion, as it is here understood, are 
 bound to be of a similar kind and origin to those raised from 
 time immemorial against the concept of motion. And as the 
 physicist gets rid of these after the example of Diogenes, who 
 stepping from his tub walked about with a "solvitur ambu- 
 lando," so here in a similar manner the first thing we have to do 
 is to oppose to all reasoning a " solvitur audiendo." But then 
 here as there, it becomes evident that the difficulties are 
 avoided, the moment that the mixture of heterogeneous con- 
 cepts is avoided. 
 
 Finally it is to be remarked, that the expression and concept 
 of fusion stands here in no relation, either essentially or his- 
 torically, with the general psychological doctrine of Herbart, in 
 which " fusion" plays such a prominent part; and which for the 
 sake of clearness everyone, who has knowledge of it, is asked 
 for the present to banish from his mind. In a subsequent chap- 
 ter, where the cause and origin of fusion are treated, we will 
 attempt to show how far Herbart's theory of fusion in general, 
 and of tonal fusion in particular, is from being correct. 
 
 Our conception of fusion has also not many points of contact 
 with the ideas which have been brought forward under the 
 same name oftentimes in the most recent psychology, and 
 in my judgment on every occasion is in contradiction with the 
 truth. 
 
 2. The Degrees of Fusion 
 
 If in the first place we confine ourselves to a tonal domain, 
 which is limited by the ratio of vibrations 1:2, I remark the
 
 PSYCHOLOGY OF TONE 623 
 
 following degrees of different tones, from the highest to the 
 lowest. 
 
 First the fusion of the octave (1:2). 
 
 Secondly that of the fifth (2:3). 
 
 Thirdly that of the fourth (3:4). 
 
 Fourthly that of the so-called natural thirds and sixths 
 (4:5, 5:6, 3:5, 5:8), between which I find in this respect no 
 clear distinctions. 
 
 Fifthly that of all the remaining musical and unmusical tonal 
 combinations, which, for my hearing at least, offer no discern- 
 ible differences of fusion, but on the contrary all the least degree 
 of it. At most the so-called natural seventh (4:7) could 
 indeed fuse somewhat more than the others. 
 
 If we employ here the modern names of the intervals, and the 
 general expression interval itself, we do so not in any musical 
 sense at all, but only to have a known and short term for the 
 numerical relations of vibrations with which we are here 
 concerned. 
 
 When we speak of degrees of fusion, we mean that we are 
 dealing with the degrees of differences, which, as is well known, 
 constantly pass over into one another, from the highest to the 
 lowest degree. Further we make use also of the general expres- 
 sion degrees effusion. 
 
 3. The Laws of Fusion 
 
 The dependence of the degrees of fusion upon the so-called 
 ratio of vibrations is the principal law of tonal fusion. In addi- 
 tion to it stand the following: 
 
 (a) The degree of fusion is independent of the tonal region. 
 In the lowest pitch, where analysis meets with difficulties, the 
 recognition and comparison of degrees of fusion become natu- 
 rally difficult and impossible. But where it is possible, we find 
 the fusion unchanged with the change of pitch, so long only as 
 the ratio of vibrations of the two tones remain the same. 
 
 Only in the very highest pitch, approximating about 4000 
 vibrations, that is, from the octave five tones above the staff up- 
 ward, do the differences of fusion appear to me, so far as I have
 
 624 CARL STUMPF 
 
 yet been able to observe, to vanish. With tuning-forks 2000: 
 3000 I still discern with full clearness the fusion of the fifth, 
 whereas with 3000:5000, 5ooo:ioooo,etc., I can discern only the 
 slightest degree of fusion at all. 
 
 (b) The degree of fusion is also independent of the strength, 
 whether indeed it be the absolute or the relative strength. 
 That it is not changed by the mere change of the absolute 
 strength of the two tones is at once clear. With the change of 
 relative strength it is again noteworthy, that ultimately ana- 
 lysis becomes impossible with great difference of strength, 
 since the softer is suppressed by the stronger tone, so 
 far as perception or even sensation is concerned. But so long 
 as they remain distinguishable, I cannot notice any change of 
 the degree of fusion. For example, if I make c and g at first of 
 equal strength, then c noticeably stronger than g, or the 
 reverse. 
 
 (c) The degree of fusion of two given tones is in no way influ- 
 enced by the addition at pleasure of a third and fourth tone. 
 Indeed, a consonance is so much the less easily analyzed, the 
 more tones it contains, and becomes at last wholly confused and 
 not analysable. But so long as two tones are at all distinguish- 
 able in a composite sound, their fusion also is recognised as the 
 same as if the two alone were sounded. 
 
 In this proposition together with (6) , there is also expressed 
 the fact, that the overtones especially, and thereby the timbre, 
 make no change in the ratio of two fundamental tones of mus- 
 ical sounds, as is also confirmed by direct observation. 
 
 (d) As in general the changes of stimulus below a certain 
 degree effect no perceptible changes of sensation, so likewise 
 very minute deviations of the number of vibrations from the 
 abovementioned ratios create no perceptible change of the 
 degree of fusion. If the deviation is increased, the fusion in all 
 pairs of tones which do not belong to the very lowest degree 
 of fusion, passes into this degree without running through the 
 intermediate degrees, if any. And this transition occurs the 
 more rapidly, (with the smaller relative differences of vibra- 
 tions), the greater was the initial fusion.
 
 PSYCHOLOGY OF TONE 625 
 
 We say, as is known in the case of small but perceptible devi- 
 ations, that the interval is " out of tune " or " impure." This 
 saying possesses, as we may remark by anticipation, not 
 merely a reference to the disagreeable feeling which is only a 
 consequence of perception, but above all to an actual and 
 perceived behavior of sensations. 
 
 With regard to the size of the deviation in which the change 
 of the degree of fusion is discernible, practise besides other cir- 
 cumstances (e.g., pitch) makes a difference. But this forms no 
 objection to the definition of the degree of fusion as a fact of 
 sensation. As a sensation itself can change, so also can the ratio 
 of two sensations, without the change being remarked; and this 
 can be imperceptible to another through the equality of sensa- 
 tions, (not merely of stimuli). 
 
 (e) The fusion remains and retains its degree when both 
 tones do not affect the same ear, but one is presented exclu- 
 sively to the right, the other exclusively to the left. A tuning- 
 fork of medium pitch, that is not sounded too loud, held before 
 one ear is not perceived by the other, as we discover from the 
 fact, that if the first is stopped up nothing is heard. If now we 
 apply two forks which for example form a fifth, one to each ear, 
 no difference is observable between this fusion, and the percep- 
 tion by one and the same ear. On the contrary, the analysis 
 can be facilitated by this process (cf 23, i and 24, a). 
 
 (/) Fusion remains also in the mere representation of the 
 imagination. If I merely represent c and g as sounding at the 
 same time, I can conceive them only as fusing, and indeed with 
 the definite degree of fusion which they possess in the actual 
 hearing. The same is true of any other two tones. A priori this 
 is not necessarily to be expected, even if we recognise sensations 
 and representations of the imagination in general as similar. 
 Not all properties of simultaneous sensations pass over of neces- 
 sity to the representation of the imagination: c and c sharp in 
 actual hearing (upon the same ear) necessarily make vibrations, 
 but in the imagination I can represent them perfectly without 
 vibrations. Moreover, if I represent them as vibrating, I ran 
 represent them with slow or quick, strong or weak vibra-
 
 626 CARL STUMPF 
 
 tions; whilst the choice of the degree of fusion is not free 
 to me. 
 
 In regard to the representation of the imagination we must 
 accordingly complete the fundamental law as follows: Tones 
 represented as simultaneous fuse in the degree which corre- 
 sponds to the ratio of vibration of tones of the same pitch 
 created objectively. 
 
 (g) If we proceed above an octave, the same degrees of fusion 
 recur with the rates of vibration increased one or more octaves. 
 The ninths have the same fusion as the seconds, the tenths as 
 the thirds, the double and triple octave as the octave; and in 
 general m:w.2 x , the same a.sm:n, if m < and x a small whole 
 number. 
 
 We must not be misled here by the greater ease of the ana- 
 lysis. C and c 4 sounding together are more easily and certainly 
 analyzed by the unmusical than C and c, even than C and G; 
 although these two tones fuse less with one another than the 
 former. The analysis depends upon very different conditions; 
 it is peculiarly difficult especially in the lowest register; it is 
 further facilitated by increase in the difference of pitch of the 
 two tones. But if analysis takes place in both cases, we shall 
 also further find, that C and c 4 are nevertheless in sensuous 
 impression less perfectly sundered than C and G, and not more 
 perfectly than C and c. 
 
 If I compare the sounds of the tuning-fork CG with Cg, CA 
 with Ca, etc., it is evident to me, that detection of difference 
 between every second combination is always easier, but the 
 fusion is the same as in the first. 
 
 If I play upon the d l string of the violin the octave d l , and 
 then the double octave d 2 (on the a 1 string), I have in both cases 
 the same impression of homogeneity and of approximation to a 
 real tonal unity. We can always for sake of contrast play 
 the d in question with the free e 2 string; the difference of the 
 fusion is always the same, that of the highest and of the lowest 
 degree. 
 
 If an orchestra plays the entire 7 octave tones from C up to 
 c 6 , we still designate the impression as unison. The seven tones
 
 PSYCHOLOGY OF TONE 627 
 
 are more homogeneous than the two tones c and a, to say no- 
 thing of c and b. We cannot here assume as true, that only the 
 two neighboring members of the series always fuse with one 
 another, C with c, c with c 1 , etc., and that the farther removed do 
 so only by means of the intermediate ; for if C and c 5 fuse by 
 themselves less than C and c, or even c and g, this could not be 
 changed by means of the intervening octaves, according to (c). 
 Moreover, the special laws enunciated in the preceding prin- 
 ciples can be directly observed in the enlarged intervals them- 
 selves. For example, this is true of that presented under (b) , the 
 recognition of which with many possibly meets with difficulties. 
 Play upon the piano first c alone and observe the overtone g 1 
 (the twelfth), which we clearly hear sound at the same time, in 
 respect to its fusion with the fundamental tone. Now add g 1 , 
 by means of which this tone, too, becomes noticeably strength- 
 ened: the fusion with c remains unchanged. The fusion, there- 
 fore, in the intervals beyond the octave is independent also of 
 the relation of strength. 
 
 4. Rules of observation 
 
 Those who are skilled in the judgment of tones can test, 
 whether what precedes corresponds to their own perceptions. 
 Where it is a question of relations which are based on the 
 material of sensation itself, there is, indeed, no fear that very 
 great individual differences will appear in those hearing 
 normally. It is rather to be expected, that those capable of 
 judgment will find among themselves more and more harmony, 
 the longer and more carefully they examine. But I will not by 
 any means claim to have found the correct solution in each of 
 the mentioned points, and to have expressed it in an entirely 
 correct manner. 
 
 It is necessary in these observations above everything to 
 direct the attention exclusively upon the point in question, 
 especially, therefore, to disregard theoretical knowledge of rela- 
 tionship, etc., as well as of the musical significance and position; 
 and also to disregard the impression of feeling of an interval, 
 whether it be harmonious or unharmonious, agreeable or dis-
 
 628 CARL STUMPF 
 
 agreeable, and furthermore in a different way agreeable or 
 disagreeable. The character and value of the feeling of an inter- 
 val depends, indeed, as we shall show later, upon its degree of 
 fusion ; but yet not solely upon this. The most agreeable inter- 
 val is not one of strongest fusion. The great seventh is in 
 isolated state more disagreeable than the small; and this cannot 
 be mistaken for a lesser fusion, or explained by that. It has other 
 grounds. The same is true of the great and small third, etc. 
 
 In general it will also be well first to take tones of the same 
 sensation-strength, because then the danger is best avoided 
 that any one of them should remain totally imperceptible or 
 obscure. In order to produce similar strength of sensation in 
 large intervals of tone, one must frequently according to the 
 instrument give the higher tone with less physical strength. 
 Further the greatest possible similarity in the initial utterance 
 and duration of tone is naturally preferable, since inequalities of 
 every kind divert the attention. Likewise, similar tone color is 
 desirable, although this is of no influence in the fusion of the 
 keynotes. Purity of interval, that is, exact harmony with the 
 respective numbers of vibrations, is so much the more neces- 
 sary, the more acute the hearing; although minimal variations, 
 which can never be avoided, do no important injury to the 
 fusion particularly in the lower grades. The piano with its 
 tempered pitch permits the differences of the higher degrees 
 still to appear (the octave is even here pure) ; but not between 
 the last two degrees. It is even here c:d sharp =: c:e flat, and 
 c:g sharp =c:a flat. 
 
 But all these are measures of the kind that are matters of 
 course for every observation. Nobody affirms that the phe- 
 nomenon would be perceptible under only especially chosen 
 circumstances. It is on the contrary in itself one of the most 
 obvious, and so to speak most unavoidable, in the whole subject 
 of unison. The entire task consists only in not confounding 
 it with others which are based upon it, particularly with facts 
 of judgment and of feeling (possibility and impossibility of 
 analysis, pleasurableness and impleasureableness of an in- 
 terval).
 
 PSYCHOLOGY OF TONE 629 
 
 5. Confirmation through unmusical persons 
 
 For the guidance of my own judgment I have pursued still 
 another method. As the question is here put, it can only be ad- 
 dressed to those who are sufficiently endowed with power of 
 tonal observations to analyze the fifths and octaves easily and 
 directly. With such there exists only the difficulty last men-* 
 tioned, and many times previously touched upon, as to the 
 dominating consciousness of the harmonious character and sen- 
 sation-value of the interval. But we can obtain information 
 also in an indirect way through unmusical persons, and those 
 unpractised in the judgment of tones: by means of the use of 
 the aforementioned difficulty of analysis. The different degrees 
 of fusion must reveal themselves in the different degrees of dif- 
 ficulty of analysis, if all the remaining circumstances upon 
 which the latter depend are taken precisely equal. We shall 
 recognise them in the results. In this way we can even obtain 
 figures, by the enumeration of correct and false judgments, up- 
 on the question, whether one or more tones are present in each 
 interval. The combinations of more strongly fusing tones 
 under otherwise similar conditions will more rarely be judged 
 to be two tones than those fusing less strongly. 
 
 20. THE CAUSE OF TONAL FUSION 
 
 6. The cause of fusion is physiological 
 
 All the attempts at the explanation of tonal fusion previously 
 considered have been psychological. Their failure signifies, that 
 we can by no means seek the source of tonal fusion in the 
 psychological domain. In favor of this view from the outset 
 appeared to be the circumstance, that such tonal fusion is a fact 
 of sensation, a relation immanent in simultaneous tonal quali- 
 ties, and independent of practice in the individual life. But 
 relations of sensation, like the sensations themselves, are not 
 referable to more remote causes, but only to physical. 
 
 The physically objective characteristics of successive waves 
 do not help us at all. To be sure, the total wave formed by two
 
 630 CARL STUMPF 
 
 waves in the ratio i : 2 is most similar to the simple sine-wave; 
 then follows 2:3, 3:4, etc. more and more complicated forms. 
 But these .objective relations are, as was previously remarked, 
 neither themselves the content of any sensation, nor the imme- 
 diate cause of one; but on the contrary, they lie far back in the 
 chain of causes. Moreover, if we consider it more closely from 
 that standpoint, we find, that the so-called characteristic of the 
 vibrations of the air disappear in the organ, if it is true here 
 that every compound vibration is resolved into simple vibra- 
 tions. Also as was previously mentioned, the circumstance that 
 colors in which objectively the selfsame relations of vibrations 
 occur, (1:2 in the extreme outer colors of the spectrum, 2:3 in 
 blue and red, orange and indigo-violet, greenish-blue, and 
 extreme red), reveal no phenomenon analogous to the tonal 
 fusion, must prevent the objective forms of the waves from 
 being made in any way responsible for the fusion. 
 
 That also within the organ, especially of the labyrinth in the 
 ear, the physical processes do not yet possess that characteris- 
 tic which corresponds to the fusion of the tones in sensation, 
 appears not merely from the just-mentioned isolated transmis- 
 sion but also from the fact, that the fusion is perceptible in the 
 same way when the two tones are divided between the two ears, 
 as well as when they are merely imagined. At least it would be 
 a violent and improbable assumption, that the process creating 
 fusion in the case of simultaneous hearing occurs in the ear 
 itself, but in the division of the tones occurs first in the brain. 
 
 Certain differences in the last processes of the centre of hear- 
 ing must therefore correspond to the differences in the degrees 
 of fusion as a physical correlate, or as a cause, (according as one 
 thinks in a monistic or a dualistic way). But we know nothing 
 of what nature these differences are, for this reason, if for no 
 other, that in general we know nothing concerning the nature 
 of the last processes. Indeed I must say, that although up to a 
 certain point we can express in physical or chemical terms the 
 occurrence of vibrations, competition, contrast, and other phe- 
 nomena, in respect to the processes of the brain, which might 
 lie at the basis of the phenomena of fusion, such a hypothetical
 
 PSYCHOLOGY OF TONE 631 
 
 image does not even occur to me. Perhaps the practised fancy 
 of certain mind readers will succeed better. But who knows, 
 whether we shall not find ourselves gradually induced to recast 
 or to extend our fundamental physical conceptions. Is it then a 
 priori certain that the world beyond consciousness, (to which 
 the brain indeed belongs), is spatial, and only spatial, or may 
 be so conceived? Spatial properties are nothing but a small 
 part of those which we abstract from our sense perceptions. We 
 have found them serviceable for the rational construction of 
 the external world, and for the derivation of its laws. But 
 all other qualitative and remaining moments and relations 
 of sensations have of themselves the same right to be trans- 
 ferred to the external world. And possibly fusion is itself des- 
 tined sometime to participate in this dignity ; perchance in ap- 
 plication to chemical processes. But this is a mere play with 
 the possibilities of thought, and we will not in place of physio- 
 logical indulge in metaphysiological fancies. 
 
 If we are willing in the lack of adequate apprehension to con- 
 tent ourselves with an abstract notion (which after all is no- 
 thing but a word), we might once more speak of specific ener- 
 gies. The specific energies, which lie at the foundation of fusion, 
 have only this peculiarity, that they are not aroused by means 
 of isolated stimuli, but by the concurrence of two stimuli. For 
 this reason, we can call them specific energies of a higher rank, 
 or still better, specific synergies. By such specific synergy we 
 should therefore understand a determinate mode of coopera- 
 tion of two nervous formations, having its ground in the struc- 
 j ture of the brain, of such a kind that whenever these two 
 formations produce their corresponding sensations, there arises 
 at the same time a determinate degree of fusion of these sensa- 
 tions. As adequate and inadequate stimuli are distinguished in 
 the production of sensations, by means of both of which never- 
 theless one and the same quality of sensation is produced ; so 
 likewise a determinate degree of fusion is here not united as 
 such exclusively and unconditionally to the " adequate " stimu- 
 lus-relation, (e.g., 1:2), but the same specific synergy can also, 
 by way of exception, be aroused by another objective relation of
 
 632 CARL STUMPF 
 
 vibration, and the octave relation, etc., be established in the 
 sensation. On the other hand, these specific energies of higher 
 rank are, to be sure, inseparably united with those of the first 
 rank: for the fusion reveals itself constantly as the same be- 
 tween two determinate qualities of tone. 
 
 That fusion remains preserved in imagination, is not opposed 
 to what has been said, but is only a new example in proof of the 
 fact, that the mere ideas of the imagination have themselves a 
 physical basis, and indeed in general the same as the sensations. 
 
 In contrast to the theories of fusion already summarized, 
 which give a very exact explanation concerning the process, our 
 formulation must appear slight. But we would prefer honor- 
 able poverty to suspicious wealth, and remain mindful of the 
 fact, that everywhere no other formulation than one in such 
 general and abstract terms, is as yet certainly possible for the 
 immediate and ultimate bases of our entire sensational life.
 
 WILLIAM JAMES 
 
 (1842-1910) 
 
 PSYCHOLOGY* 
 
 CHAPTER XI! THE STREAM OF CONSCIOUS- 
 NESS 
 
 The order of our study must be analytic. We are now pre- 
 pared to begin the introspective study of the adult conscious- 
 ness itself. Most books adopt the so-called synthetic method. 
 Starting with ' simple ideas of sensation/ and regarding these 
 as so many atoms, they proceed to build up the higher states of 
 mind out of their ' association/ ' integration/ or ' fusion/ as 
 houses are built by the agglutination of bricks. This has the 
 didactic advantages which the synthetic method usually has. 
 But it commits one beforehand to the very questionable theory 
 that our higher states of consciousness are compounds of units; 
 and instead of starting with what the reader directly knows, 
 namely his total concrete states of mind, it starts with a set of 
 supposed ' simple ideas ' with which he has no immediate 
 acquaintance at -all, and concerning whose alleged interactions 
 he is much at the mercy of any plausible phrase. On every 
 ground, then, the method of advancing from the simple to the 
 compound exposes us to illusion. All pedants and abstrac- 
 tionists will naturally hate to abandon it. But a student who 
 loves the fulness of human nature will prefer to follow the 
 ' analytic' method, and to begin with the most concrete facts, 
 those with which he has a daily acquaintance in his own inner 
 life. The analytic method will discover in due time the ele- 
 
 * New York, Henry Holt and Company, 1892. 
 
 t This chapter 6rst appeared in substance as an article On Some Omissions 
 of Introspective Psychology in Mind for January, 1884; and again as a chapter 
 on The Stream of Thought in the author's Principles of Psychology in 1890.
 
 634 WILLIAM JAMES 
 
 mentary parts, if such exist, without danger of precipitate as- 
 sumption. The reader will bear in mind that our own chapters 
 on sensation have dealt mainly with the physiological condi- 
 tions thereof. They were put first as a mere matter of conven- 
 ience, because incoming currents come first. Psychologically 
 they might better have come last. Pure sensations were de- 
 scribed [Psychology, page 12] as processes which in adult life are 
 well-nigh unknown, and nothing was said which could for a 
 moment lead the reader to suppose that they were the elements 
 of composition of the higher states of mind. 
 
 The Fundamental Fact- The first and foremost concrete 
 fact which every one will affirm to belong to his inner experi- 
 ence is the fact that consciousness of some sort goes on. ' States of 
 mind ' succeed each other in him. If we could say in English ' it 
 thinks,' as we say ' it rains ' or ' it blows/ we should be stating 
 the fact most simply and with the minimum of assumption. 
 As we cannot, we must simply say that thought goes on. 
 
 Four Characters in Consciousness. How does it .go on? 
 We notice immediately four important characters in the pro- 
 cess, of which it shall be the duty of the present chapter to 
 treat in a general way: 
 
 (1) Every ' state ' tends to be part of a personal conscious- 
 ness. 
 
 (2) Within each personal consciousness states are always 
 changing. 
 
 (3) Each personal consciousness is sensibly continuous. 
 
 (4) It is interested in some parts of its object to the exclusion 
 ofothers, and welcomes or rejects chooses from among them, 
 in a word all the while. 
 
 In considering these four points successively, we shall have 
 to plunge in medias res as regards our nomenclature and use 
 psychological terms which can only be adequately defined in 
 later chapters of the book. But every one knows what the 
 terms mean in a rough way; and it is only in a rough way that 
 we are now to take them. This chapter is like a painter's first 
 charcoal sketch upon his canvas, in which no niceties appear. 
 
 When I say every ' state ' or ' thought ' is part of a personal
 
 PSYCHOLOGY 635 
 
 consciousness, ' personal consciousness ' is one of the terms in 
 question. Its meaning we know so long as no one asks us to 
 define it, but to give an accurate account of it is the most diffi- 
 cult of philosophic tasks. This task we must confront in the 
 next chapter; here a preliminary word will suffice. 
 
 In this room this lecture-room, say there are a multi- 
 tude of thoughts, yours and mine, some of which cohere mutu- 
 ally, and some not. They are as little each-for-itself and recip- 
 rocally independent as they are all-belonging-together. They 
 are neither: no one of them is separate, but each belongs with 
 certain others and with none beside. My thought belongs with 
 my other thoughts, and your thought with your other thoughts. 
 Whether anywhere in the room there be a mere thought, which 
 is nobody's thought, we have no means of ascertaining, for we 
 have no experience of its like. The only states of consciousness 
 that we naturally deal with are found in personal conscious- 
 nesses, minds, selves, concrete particular I's and you's. 
 
 Each of these minds keeps its own thoughts to itself. There 
 is no giving or bartering between them. No thought even 
 comes into direct sight of a thought in another personal con- 
 sciousness than its own. Absolute insulation, irreducible 
 pluralism, is the law. It seems as if the elementary psychic fact 
 were not thought or this thought or that thought, but my thought, 
 every thought being owned. Neither contemporaneity, nor 
 proximity in space, nor similarity of quality and content are 
 able to fuse thoughts together which are sundered by this bar- 
 rier of belonging to different personal minds. The breaches be- 
 tween such thoughts are the most absolute breaches in nature. 
 Every one will recognize this to be true, so long as the existence 
 of something corresponding to the term ' personal mind ' is all 
 that is insisted on, without any particular view of its nature 
 being implied. On these terms the personal self rather than the 
 thought might be treated as the immediate datum in psycho- 
 logy. The universal conscious fact is not ' feelings and thoughts 
 exist,' but ' I think ' and ' I feel.' No psychology, at any rate, 
 can question the existence of personal selves. Thoughts con- 
 nected as we feel them to be connected are what we mean by
 
 636 WILLIAM JAMES 
 
 personal selves. The worst a psychology can do is so to inter- 
 pret the nature of these selves as to rob them of their worth. 
 
 Consciousness is inconstant change. I do not mean by this 
 to say that no one state of mind has any duration even if 
 true, that would be hard to establish. What I wish to lay stress 
 on is this, that no state once gone can recur and be identical with 
 what it was before. Now we are seeing, now hearing; now rea- 
 soning, now willing; now recollecting, now expecting; now lov- 
 ing, now hating; and in a hundred other ways we know our 
 minds to be alternately engaged. But all these are complex 
 states, it may be said, produced by combination of simpler 
 ones; do not the simpler ones follow a different law? Are not 
 the sensations which we get from the same object, for example, 
 always the same? Does not the same piano-key, struck with 
 the same force, make us hear in the same way? Does not the 
 same grass give us the same feeling of green, the same sky the 
 same feeling of blue, and do we not get the same olfactory sens- 
 ation no matter how many times we put our nose to the same 
 flask of cologne? It seems a piece of metaphysical sophistry to 
 suggest that we do not; and yet a close attention to the matter 
 shows that there is no proof that an incoming current ever gives us 
 just the same bodily sensation twice. 
 
 What is got twice is the same OBJECT. We hear the same note 
 over and over again; we see the same quality of green, or smell 
 the same objective perfume, or experience the same species of 
 pain. The realities, concrete and abstract, physical and ideal, 
 whose permanent existence we believe in, seem to be constantly 
 coming up again before our thought, and lead us, in our care- 
 lessness, to suppose that our ' ideas ' of them are the same 
 ideas. When we come, some time later, to the chapter on Per- 
 ception, we shall see how inveterate is our habit of simply using 
 our sensible impressions as stepping-stones to pass over to the 
 recognition of the realities whose presence they reveal. The 
 grass out of the window now looks to me of the same green in 
 the sun as in the shade, and yet a painter would have to paint 
 one part of it dark brown, another part bright yellow, to give 
 its real sensational effect. We take no heed, as a rule, of the dif-
 
 PSYCHOLOGY 637 
 
 ferent way in which the same things look and sound and smell 
 at different distances and under different circumstances. The 
 sameness of the things is what we are concerned to ascertain; 
 and any sensations that assure us of that will probably be con- 
 sidered in a rough way to be the same with each other. This is 
 what makes off-hand testimony about the subjective identity 
 of different sensations well-nigh worthless as a proof of the fact. 
 The entire history of what is called Sensation is a commentary 
 on our inability to tell whether two sensible qualities received 
 apart are exactly alike. What appeals to our attention far 
 more than the absolute quality of an impression is its ratio to 
 whatever other impressions we may have at the same time. 
 When everything is dark a somewhat less dark sensation makes 
 us see an object white. Helmholtz calculates that the white 
 marble painted in a picture representing an architectural view 
 by moonlight is, when seen by daylight, from ten to twenty 
 thousand times brighter than the real moonlit marble would be. 
 
 Such a difference as this could never have been sensibly 
 learned ; it had to be inferred from a series of indirect consider- 
 ations. These make us believe that our sensibility is altering 
 all the time, so that the same object cannot easily give us the 
 same sensation over again. We feel things differently accord- 
 ingly as we are sleepy or awake, hungry or full, fresh or tired; 
 differently at night and in the morning, differently in summer 
 and in winter; and above all, differently in childhood, manhood, 
 and old age. And yet we never doubt that our feelings reveal 
 the same world, with the same sensible qualities and the same 
 sensible things occupying it. The difference of the sensibility is 
 shown best by the difference of our emotion about the things 
 from one age to another, or when we are in different organic 
 moods. What was bright and exciting becomes weary, flat, 
 and unprofitable. The bird's song is tedious, the breeze is 
 mournful, the sky is sad. 
 
 To these indirect presumptions that our sensations, following 
 the mutations of our capacity for feeling, are always under- 
 going an essential change, must be added another presumption, 
 based on what must happen in the grain. Every sensation corre-
 
 638 WILLIAM JAMES 
 
 sponds to some cerebral action. For an identical sensation to 
 recur it would have to occur the second time in an unmodified 
 brain. But as this, strictly speaking, is a physiological impossi- 
 bility, so is an unmodified feeling an impossibility; for to every 
 brain-modification, however small, we suppose that there must 
 correspond a change of equal amount in the consciousness 
 which the brain subserves. 
 
 But if the assumption of ' simple sensations ' recurring in 
 immutable shape is so easily shown to be baseless, how much 
 more baseless is the assumption of immutability in the larger 
 masses of our thought ! 
 
 For there it is obvious and palpable that our state of mind is 
 never precisely the same. Every thought we have of a given 
 fact is, strictly speaking, unique, and only bears a resemblance 
 of kind with our other thoughts of the same fact. When the 
 identical fact recurs, we must think of it in a fresh manner, see 
 it under a somewhat different angle, apprehend it in different 
 relations from those in which it last appeared. And the thought 
 by which we cognize it is the thought of it-in-those-relations, a 
 thought suffused with the consciousness of all that dim con- 
 text. Often we are ourselves struck at the strange differences in 
 our successive views of the same thing. We wonder how we 
 ever could have opined as we did last month about a certain 
 matter. We have outgrown the possibility of that state of 
 mind, we know not how. From one year to another we see 
 things in new lights. What was unreal has grown real, and what 
 was exciting is insipid. The friends we used to care the world 
 for are shrunken to shadows; the women once so divine, the 
 stars, the woods, and the waters, how now so dull and common ! 
 the young girls that brought an aura of infinity, at present 
 hardly distinguishable existences; the pictures so empty; and as 
 for the books, what was there to find so mysteriously significant 
 in Goethe, or in John Mill so full of weight? Instead of all this, 
 more zestful than ever is the work, the work; and fuller and 
 deeper the import of common duties and of common goods. 
 
 I am sure that this concrete and total manner of regarding 
 the mind's changes is the only true manner, difficult as it may
 
 PSYCHOLOGY 639 
 
 be to carry it out in detail. If anything seems obscure about it, 
 it will grow clearer as we advance. Meanwhile, if it be true, 
 it is certainly also true that no two ' ideas ' are ever exactly the 
 same, which is the proposition we started to prove. The pro- 
 position is more important theoretically than it at first sight 
 seems. For it makes it already impossible for us to follow 
 obediently in the footprints of either the Lockian or the 
 Herbartian school, schools which have had almost unlimited 
 influence in Germany and among ourselves. No doubt it is 
 often convenient to formulate the mental facts in an atomistic 
 sort of way, and to treat the higher states of consciousness as if 
 they were all built out of unchanging simple ideas which ' pass 
 and turn again.' It is convenient often to treat curves as if they 
 were composed of small straight lines, and electricity and nerve- 
 force as if they were fluids. But in the one case as in the other 
 we must never forget that we are talking symbolically, and that 
 there is nothing in nature to answer to our words. A perma- 
 nently existing ' Idea ' which makes its appearance before the 
 footlights of consciousness at periodical intervals is as mythological 
 an entity as the Jack of Spades. 
 
 Within each personal consciousness, thought is sensibly 
 continuous. I can only define ' continuous ' as that which is 
 without breach, crack, or division. The only breaches that can 
 well be conceived to occur within the limits of a single mind 
 would either be interruptions, time-gaps during which the con- 
 sciousness went out ; or they would be breaks in the content of 
 the thought, so abrupt that what followed had no connection 
 whatever with what went before. The proposition that con- 
 sciousness feels continuous, means two things: 
 
 a. That even where there is a time-gap the consciousness 
 after it feels as if it belonged together with the consciousness 
 before it, as another part of the same self; 
 
 b. That the changes from one moment to another in the 
 quality of the consciousness are never absolutely abrupt. 
 
 The case of the time-gaps, as the simplest, shall be taken 
 first, 
 a. When Paul and Peter wake up in the same bed, and recog-
 
 640 WILLIAM JAMES 
 
 nize that they have been asleep, each one of them mentally 
 reaches back and makes connection with but one of the two 
 streams of thought which were broken by the sleeping hours. 
 As the current of an electrode buried in the ground unerringly 
 finds its way to its own similarly buried mate, across no matter 
 how much intervening earth ; so Peter's present instantly finds 
 out Peter's past, and never by mistake knits itself on to that of 
 Paul. Paul's thought in turn is as little liable to go astray. The 
 past thought of Peter is appropriated by the present Peter 
 alone. He may have a knowledge, and a correct one too, of what 
 Paul's last drowsy states of mind were as he sank into sleep, 
 but it is an entirely different sort of knowledge from that which 
 he has of his own last states. He remembers his own states, 
 whilst he only conceives Paul's. Remembrance is like direct 
 feeling; its object is suffused with a warmth and intimacy to 
 which no object of mere conception ever attains. This quality 
 of warmth and intimacy and immediacy is what Peter's present 
 thought also possesses for itself. So sure as this present is me, is 
 mine, it says, so sure is anything else that comes with the same 
 warmth and intimacy and immediacy, me and mine. What the 
 qualities called warmth and intimacy may in themselves be will 
 have to be matter for future consideration. But whatever past 
 states appear with those qualities must be admitted to receive 
 the greeting of the present mental state, to be owned by it, and 
 accepted as belonging together with it in a common self. This 
 community of self is what the time-gap cannot break in twain, 
 and is why a present thought, although not ignorant of the 
 time-gap, can still regard itself as continuous with certain 
 chosen portions of the past. 
 
 Consciousness, then, does not appear to itself chopped up in 
 bits. Such words as ' chain ' or ' train ' do not describe it fitly 
 as it presents itself in the first instance. It is nothing jointed ; 
 it flows. ' A ' river ' or a ' stream ' are the metaphors by which 
 it is most naturally described. In talking of it hereafter, let us 
 call it the stream of thought, of consciousness, or of subjective life. 
 
 b. But now there appears, even within the limits of the same 
 self, and between thoughts all of which alike have this same
 
 PSYCHOLOGY 641 
 
 sense of belonging together, a kind of jointing and separateness 
 among the parts, of which this statement seems to take no 
 account. I refer to the breaks that are produced by sudden 
 contrasts in the quality of the successive segments of the stream 
 of thought. If the words ' chain ' and ' train ' had no natural 
 fitness in them, how came such words to be used at all? Does 
 not a loud explosion rend the consciousness upon which it 
 abruptly breaks, in twain? No; for even into our awareness of 
 the thunder the awareness of the previous silence creeps and 
 continues; for what we hear when the thunder crashes is 
 not thunder pure, but thunder-breaking-upon-silence-and-con- 
 trasting-with-it. Our feeling of the same objective thunder, 
 coming in this way, is quite different from what it would be 
 were the thunder a continuation of previous thunder. The 
 thunder itself we believe to abolish and exclude the silence; but 
 the feeling of the thunder is also a feeling of the silence as just 
 gone; and it would be difficult to find in the actual concrete 
 consciousness of man a feeling so limited to the present as not 
 to have an inkling of anything that went before. 
 
 * Substantive ' and c Transitive ' States of Mind. When 
 we take a general view of the wonderful stream of our con- 
 sciousness, what strikes us first is the different pace of its parts. 
 Like a bird's life, it seems to be an alternation of flights and 
 perchings. The rhythm of language expresses this, where every 
 thought is expressed in a sentence, and every sentence closed by 
 a period. The resting-places are usually occupied by sensorial 
 imaginations of some sort, whose peculiarity is that they can be 
 held before the mind for an indefinite time, and contemplated 
 without changing; the places of flight are filled with thoughts 
 of relations, static or dynamic, that for the most part obtain 
 between the matters contemplated in the periods of compara- 
 tive rest. 
 
 Let us call the resting-places the ' substantive parts, 1 and the' 
 places of flight the * transitive parts 1 of the stream of thought. It 
 then appears that our thinking tends at all times towards some 
 other substantive part than the one from which it has just been 
 dislodged. And we may say that the main use of the tran-
 
 642 WILLIAM JAMES 
 
 sitive parts is to lead us from one substantive conclusion to 
 another. 
 
 Now it is very difficult, introspectively, to see the transitive 
 parts for what they really are. If they are but flights to a con- 
 clusion, stopping them to look at them before the conclusion is 
 reached is really annihilating them. Whilst if we wait till the 
 conclusion be reached, it so exceeds them in vigor and stability 
 that it quite eclipses and swallows them up in its glare. Let 
 anyone try to cut a thought across in the middle and get a look 
 at its section, and he will see how difficult the introspective ob- 
 servation of the transitive tracts is. The rush of the thought is 
 so headlong that it almost always brings us up at the conclusion 
 before we can arrest it. Or if our purpose is nimble enough and 
 we do arrest it, it ceases forthwith to be itself. As a snowflake 
 crystal caught in the warm hand is no longer a crystal but a 
 drop, so, instead of catching the feeling of relation moving to 
 its term, we find we have caught some substantive thing, 
 usually the last word we were pronouncing, statically taken, 
 and with its function, tendency, and particular meaning in the 
 sentence quite evaporated. The attempt at introspective 
 analysis in these cases is in fact like seizing a spinning top to 
 catch its motion, or trying to turn up the gas quickly enough to 
 see how the darkness looks. And the challenge to produce these 
 transitive states of consciousness, which is sure to be thrown by 
 doubting psychologists at anyone who contends for their exist- 
 ence, is as unfair as Zeno's treatment of the advocates of mo- 
 tion, when, asking them to point out in what place an arrow is 
 when it moves, he argues the falsity of their thesis from their 
 inability to make to so preposterous a question an immediate 
 reply. 
 
 The results of this introspective difficulty are baleful. If to 
 hold fast and observe the transitive parts of thought's stream 
 be so hard, then the great blunder to which all schools are liable 
 must be the failure to register them, and the undue emphasiz- 
 ing of the more substantive parts of the stream. Now the 
 blunder has historically worked in two ways. One set of 
 thinkers have been led by it to Sensationalism. Unable to lay
 
 PSYCHOLOGY 643 
 
 their hands on any substantive feelings corresponding to the 
 innumerable relations and forms of connection between the 
 sensible things of the world, finding no named mental states 
 mirroring such relations, they have for the most part denied 
 that any such states exist; and many of them, like Hume, have 
 gone on to deny the reality of most relations out of the mind as 
 well as in it. Simple substantive ' ideas,' sensations and their 
 copies, juxtaposed like dominoes in a game, but really separate, 
 everything else verbal illusion, such is the upshot of this 
 view. The Intellectualists, on the other hand, unable to give up 
 the reality of relations extra mentem, but equally unable to 
 point to any distinct substantive feelings in which they were 
 known, have made the same admission that such feelings do not 
 exist. But they have drawn an opposite conclusion. The rela- 
 tions must be known, they say, in something that is no feeling, 
 no mental ' state,' continuous and consubstantial with the sub- 
 jective tissue out of which sensations and other substantive 
 conditions of consciousness are made. They must be known by 
 something that lies on an entirely different plane, by an actus 
 purus of Thought, Intellect, or Reason, all written with capitals 
 and considered to mean something unutterably superior to any 
 passing perishing fact of sensibility whatever. 
 
 But from our point of view both Intellectualists and Sensa- 
 tionalists are wrong. If there be such things as feelings at all, 
 then so surely as relations between objects exist in rerum natura, 
 so surely, and more surely, do feelings exist to which these relations 
 are known. There is not a conjunction or a preposition, and 
 hardly an adverbial phrase, syntactic form, or inflection of 
 voice, in human speech, that does not express some shading or 
 other of relation which we at some moment actually feel to exist 
 between the larger objects of our thought. If we speak object- 
 ively, it is the real relations that appear revealed; if we speak 
 subjectively, it is the stream of consciousness that matches each 
 of them by an inward coloring of its own. In either case the 
 relations are numberless, and no existing language is capable of 
 doing justice to all their shades. 
 
 We ought to say a feeling of and , a feeling of if, a feeling of
 
 644 WILLIAM JAMES 
 
 but, and a feeling of by, quite as readily as we say a feeling of 
 blue or a feeling of cold. Yet we do not : so inveterate has our 
 habit become of recognizing the existence of the substantive 
 parts alone, that language almost refuses to lend itself to any 
 other use. Consider once again the analogy of the brain. We 
 believe the brain to be an organ whose internal equilibrium is 
 always in a state of change the change affecting every part. 
 The pulses of change are doubtless more violent in one place 
 than in another, their rhythm more rapid at this time than at 
 that. As in a kaleidoscope revolving at a uniform rate, al- 
 though the figures are always rearranging themselves, there are 
 instants during which the transformation seems minute and 
 interstitial and almost absent, followed by others when it 
 shoots with magical rapidity, relatively stable forms thus alter- 
 nating with forms we should not distinguish if seen again ; so in 
 the brain the perpetual rearrangement must result in some forms 
 of tension lingering relatively long, whilst others simply come 
 and pass. But if consciousness corresponds to the fact of rear- 
 rangement itself, why, if the rearrangement stop not, should the 
 consciousness ever cease? And if a lingering rearrangement 
 brings with it one kind of consciousness, why should not a swift 
 rearrangement bring another kind of consciousness as peculiar 
 as the rearrangement itself? 
 
 The object before the mind always has a ' Fringe.' There 
 are other unnamed modifications of consciousness just as im- 
 portant as the transitive states, and just as cognitive as they. 
 Examples will show what I mean. 
 
 Suppose three successive persons say to us: ' Wait! ' ' Hark! ' 
 ' Look! ' Our consciousness is thrown into three quite different 
 attitudes of expectancy, although no definite object is before it 
 in any one of the three cases. Probably no one will deny here the 
 existence of a real conscious affection, a sense of the direction 
 from which an impression is about to come, although no posi- 
 tive impression is yet there. Meanwhile we have no names for 
 the psychoses in question but the names hark, look, and wait. 
 
 Suppose We try to recall a forgotten name. The state of our 
 consciousness is peculiar. There is a gap therein; but no mere
 
 PSYCHOLOGY 645 
 
 gap. It is a gap that is intensely active. A sort of wraith of the 
 name is in it, beckoning us in a given direction, making us at 
 moments tingle with the sense of our closeness, and then letting 
 us sink back without the longed-for term. If wrong names are 
 proposed to us, this singularly definite gap acts immediately so 
 as to negate them. They do not fit into its mould. And the gap 
 of one word does not feel like the gap of another, all empty of 
 content as both might seem necessarily to be when described as 
 gaps. When I vainly try to recall the name of Spalding, my con- 
 sciousness is far removed from what it is when I vainly try to 
 recall the name of Bowles. There are innumerable conscious- 
 nesses of want, no one of which taken in itself has a name, but 
 all different from each other. Such a feeling of want is toto codo 
 other than a want of feeling: it is an intense feeling. The 
 rhythm of a lost word maybe there without a sound to clothe it; 
 or the evanescent sense of something which is the initial vowel 
 or consonant may mock us fitfully, without growing more dis- 
 tinct. Every one must know the tantalizing effect of the blank 
 rhythm of some forgotten verse, restlessly dancing in one's 
 mind, striving to be filled out with words. 
 
 What is that first instantaneous glimpse of some one's mean- 
 ing which we have, when in vulgar phrase we say we ' twig ' it? 
 Surely an altogether specific affection of our mind. And has the 
 reader never asked himself what kind of a mental fact is his 
 intention of saying a thing before he has said it? It is an entirely 
 definite intention, distinct from all other intentions, an abso- 
 lutely distinct state of consciousness, therefore; and yet how 
 much of it consists of definite sensorial images, either of words 
 or of things? Hardly anything! Linger, and the words and 
 things come into the mind; the anticipatory intention, the 
 divination is there no more. But as the words that replace it 
 arrive, it welcomes them successively and calls them right if 
 they agree with it, it rejects them and calls them wrong if they 
 do not. The intention to-say-so-and-so is the only name it can 
 receive. One may admit that a good third of our psychic 
 life consists in these rapid premonitory perspective views of 
 schemes of thought not yet articulate. How comes it about that
 
 646 WILLIAM JAMES 
 
 a man reading something aloud for the first time is able imme- 
 diately to emphasize all his words aright, unless from the very 
 first he have a sense of at least the form of the sentence yet to 
 come, which sense is fused with his consciousness of the present 
 word, and modifies its emphasis in his mind so as to make him 
 give it the proper accent as he utters it? Emphasis of this kind 
 almost altogether depends on grammatical construction. If we 
 read ' no more,' we expect presently a ' than ' ; if we read ' how- 
 ever,' it is a ' yet,' a ' still,' or a ' nevertheless/ that we expect. 
 And this foreboding of the coming verbal and grammatical 
 scheme is so practically accurate that a reader incapable of 
 understanding four ideas of the book he is reading aloud 
 can nevertheless read it with the most delicately modulated 
 expression of intelligence. 
 
 It is, the reader will see, the reinstatement of the vague and 
 inarticulate to its proper place in our mental life which I am so 
 anxious to press on the attention. Mr. Galton and Prof. Huxley 
 have, as we shall see in the chapter on Imagination, made one 
 step in advance in exploding the ridiculous theory of Hume and 
 Berkeley that we can have no images but of perfectly definite 
 things. Another is made if we overthrow the equally ridiculous 
 notion that, whilst simple objective qualities are revealed to 
 our knowledge in ' states of consciousness,' relations are not. 
 But these reforms are not half sweeping and radical enough. 
 What must be admitted is that the definite images of tradi- 
 tional psychology form but the very smallest part of our minds 
 as they actually live. The traditional psychology talks like one 
 who should say a river consists of nothing but pailsful, spoons- 
 ful, quartpotsful, barrelsful, and other moulded forms of water. 
 Even were the pails and the pots all actually standing in the 
 stream, still between them the free water would continue to 
 flow. It is just this free water of consciousness that psycholo- 
 gists resolutely overlook. Every definite image in the mind is 
 steeped and dyed in the free water that flows round it. With it 
 goes the sense of its relations, near and remote, the dying echo 
 of whence it came to us, the dawning sense of whither it is to 
 lead. The significance, the value, of the image is all in this halo
 
 PSYCHOLOGY 
 
 647 
 
 or penumbra that surrounds and escorts it, or rather that is 
 fused into one with it and has become bone of its bone and flesh 
 of its flesh; leaving it, it is true, an image of the same thing it 
 was before, but making it an image of that thing newly taken 
 and freshly understood. 
 
 Let us call the consciousness of this halo of relations around the 
 image by the name of 'psychic overtone ' or 'fringe.' 
 
 Cerebral Conditions of the 'Fringe.' Nothing is easier 
 than to symbolize these facts in terms of brain-action. Just as 
 the echo of the whence, the sense of the starting point of our 
 thought, is probably due to the dying excitement of processes 
 but a moment since vividly aroused ; so the sense of the whither, 
 the foretaste of the terminus, must be due to the waxing excite- 
 ment of tracts or processes whose psychical correlative will a 
 moment hence be the vividly present feature of our thought. 
 Represented by a curve, the neurosis underlying consciousness 
 must at any moment be like this: 
 
 Let the horizontal in Fig. i be the line of time, and let the 
 
 FIG. i. 
 
 three curves beginning at a, b, and c respectively stand for the 
 neural processes correlated with the thoughts of those three 
 letters. Each process occupies a certain time during which its 
 intensity waxes, culminates, and wanes. The process for a has 
 not yet died out, the process for c has already begun, when that 
 for b is culminating. At the time-instant represented by the 
 vertical line all three processes are present, in the intensities 
 shown by the curve. Those before c's apex were more intense a 
 moment ago; those after it will be more intense a moment
 
 648 WILLIAM JAMES 
 
 hence. If I recite a, &, c, then, at the moment of uttering b, 
 neither a nor c is out of my consciousness altogether, but both, 
 after their respective fashions, ' mix their dim lights ' with the 
 stronger b, because their processes are both awake in some 
 degree. 
 
 It is just like ' overtones ' in music: they are not separately 
 heard by the ear; they blend with the fundamental note, and 
 suffuse it, and alter it; and even so do the waxing and waning 
 brain-processes at every moment blend with and suffuse and 
 alter the psychic effect of the processes which are at their 
 culminating point. 
 
 The * Topic ' of the Thought. If we then consider the cog- 
 nitive function of different states of mind, we may feel assured 
 that the difference between those that are mere ' acquaintance ' 
 and those that are ' knowledges-a&ow/ ' is reducible almost en- 
 tirely to the absence or presence of psychic fringes or overtones. 
 Knowledge about a thing is knowledge of its relations. Ac- 
 quaintance with it is limitation to the bare impression which it 
 makes. Of most of its relations we are only aware in the penum- 
 bral nascent way of a ' fringe ' of unarticulated affinities about 
 it. And, before passing to the next topic in order, I must say a 
 little of this sense of affinity, as itself one of the most interesting 
 features of the subjective stream. 
 
 Thought may be equally rational in any sort of terms. In all 
 our voluntary thinking there is some TOPIC or SUBJECT about 
 which all the members of the thought revolve. Relation to this 
 topic or interest is constantly felt in the fringe, and particularly 
 the relation of harmony and discord, of furtherance or hind- 
 rance of the topic. Any thought the quality of whose fringe lets 
 us feel ourselves ' all right,' may be considered a thought that 
 furthers the topic. Provided we only feel its object to have a 
 place in the scheme of relations in which the topic also lies, that 
 is sufficient to make it of a relevant and appropriate portion of 
 our train of ideas. 
 
 Now we may think about our topic mainly in words, or we 
 may think about it mainly in visual or other images, but this 
 need make no difference as regards the furtherance of our
 
 PSYCHOLOGY 649 
 
 knowledge of the topic. If we only feel in the terms, whatever 
 they be, a fringe of affinity with each other and with the topic, 
 and if we are conscious of approaching a conclusion, we feel 
 that our thought is rational and right. The words in every 
 language have contracted by long association fringes of mutual 
 repugnance or affinity with each other and with the conclusion, 
 which run exactly parallel with like fringes in the visual, tactile, 
 and other ideas. The most important element of these fringes 
 is, I repeat, the mere feeling of harmony or discord, of a right or 
 wrong direction in the thought. 
 
 If we know English and French and begin a sentence in 
 French, all the later words that come are French; we hardly 
 ever drop into English. And this affinity of the French words 
 for each other is not something merely operating mechanically 
 as a brain-law, it is something we feel at the time. Our under- 
 standing of a French sentence heard never falls to so low an ebb 
 that we are not aware that the words linguistically belong to- 
 gether. Our attention can hardly so wander that if an English 
 word be suddenly introduced we shall not start at the change. 
 Such a vague sense as this of the words belonging together is 
 the very minimum of fringe that can accompany them, if 
 ' thought ' at all. Usually the vague perception that all the 
 words we hear belong to the same language and to the same 
 special vocabulary in that language, and that the grammatical 
 sequence is familiar, is practically equivalent to an admission 
 that what we hear is sense. But if an unusual foreign word be 
 introduced, if the grammar trip, or if a term from an incon- 
 gruous vocabulary suddenly appear, such as ' rat-trap ' or 
 ' plumber's bill ' in a philosophical discourse, the sentence 
 detonates as it were, we receive a shock from the incongruity, 
 and the drowsy assent is gone. The feeling of rationality in 
 these cases seems rather a negative than a positive thing, being 
 the mere absence of shock, or sense of discord, between the 
 terms of thought. 
 
 Conversely, if words do belong to the same vocabulary, and 
 if the grammatical structure is correct, sentences with abso- 
 lutely no meaning may be uttered in good faith and pass un-
 
 650 WILLIAM JAMES 
 
 challenged. Discourses at prayer-meetings, reshuffling the 
 same collection of cant phrases and the whole genus of penny-a- 
 line-isms and newspaper-reporter's flourishes give illustrations 
 of this. " The birds filled the tree- tops with their morning 
 song, making the air moist, cool, and pleasant," is a sentence 
 I remember reading once in a report of some athletic exer- 
 cises in Jerome Park. It was probably written unconsciously 
 by the hurried reporter, and read uncritically by many 
 readers. 
 
 We see, then, that it makes little or no difference in what sort 
 of mind-stuff, in what quality of imagery, our thinking goes on. 
 The only images intrinsically important are the halting-places, 
 the substantive conclusions, provisional or final, of the thought. 
 Throughout all the rest of the stream, the feelings of relation 
 are everything, and the terms related almost naught. These 
 feelings of relation, these psychic overtones, halos, suffusions, 
 or fringes about the terms, may be the same in very different 
 
 systems of imagery. A diagram 
 may help to accentuate this in- 
 difference of the mental means 
 where the end is the same. Let 
 A be some experience from 
 which a number of thinkers 
 start. Let Z be the practical 
 conclusion rationally inferrable 
 
 from it. One gets to this conclusion by one line, another by 
 another ; one follows a course of English, another of German, 
 verbal imagery. With one, visual images predominate; with 
 another, tactile. Some trains are tinged with emotions, others 
 not; some are very abridged, synthetic and rapid; others, hesi- 
 tating and broken into many steps. But when the penultimate 
 terms of all the trains, however differing inter se, finally shoot 
 into the same conclusion, we say, and rightly say, that all the 
 thinkers have had substantially the same thought. It would 
 probably astound each of them beyond measure to be let into 
 his neighbor's mind and to find how different the scenery there 
 was from that in his own.
 
 PSYCHOLOGY 651 
 
 The last peculiarity to which attention is to be drawn in this 
 first rough description of thoughts' stream is that 
 
 Consciousness is always interested more in one part of its 
 object than in another, and welcomes and rejects, or chooses, 
 all the while it thinks. 
 
 The phenomena of selective attention and of deliberative 
 will are of course patent examples of this choosing activity. 
 But few of us are aware how incessantly it is at work in opera- 
 tions not ordinarily called by these names. Accentuation and 
 Emphasis are present in every perception we have. We find it 
 quite impossible to disperse our attention impartially over a 
 number of impressions. A monotonous succession of sonorous 
 strokes is broken up into rhythms, now of one sort, now of an- 
 other, by the different accent which we place on different 
 strokes. The simplest of these rhythms is the double one, tick- 
 t6ck, tick-t6ck, tick-t6ck. Dots dispersed on a surface are per- 
 ceived in rows and groups. Lines separate into diverse figures. 
 The ubiquity of the distinctions, this and that, here and there, 
 now and then, in our minds is the result of our laying the same 
 selective emphasis on parts of place and time. 
 
 But we do far more than emphasize things, and unite some, 
 and keep others apart. We actually ignore most of the things 
 before us. Let me briefly show how this goes on. 
 
 To begin at the bottom, what are our very senses themselves, 
 but organs of selection? Out of the infinite chaos of move- 
 ments, of which physics teaches us that the outer world con- 
 sists, each sense-organ picks out those which fall within certain 
 limits of velocity. To these it responds, but ignores the rest as 
 completely as if they did not exist. Out of what is in itself an 
 undistinguishable, swarming continuum, devoid of distinction 
 or emphasis, our senses make for us, by attending to this mo- 
 tion and ignoring that, a world full of contrasts, of sharp 
 accents, of abrupt changes, of picturesque light and shade. 
 
 If the sensations we receive from a given organ have their 
 causes thus picked out for us by the conformation of the organ's 
 termination, Attention, on the other hand, out of all the sensa- 
 tions yielded, picks out certain ones as worthy of its notice and
 
 652 WILLIAM JAMES 
 
 suppresses all the rest. We notice only those sensations which 
 are signs to us of things which happen practically or aesthetically 
 to interest us, to which we therefore give substantive names, 
 and which we exalt to this exclusive status of independence and 
 dignity. But in itself, apart from my interest, a particular dust- 
 wreath on a windy day is just as much of an individual thing, 
 and just as much or as little deserves an individual name, as 
 my own body does. 
 
 And then, among the sensations we get from each separate 
 thing, what happens? The mind selects again. It chooses cer- 
 tain of the sensations to represent the thing most truly, and 
 considers the rest as its appearances, modified by the condi- 
 tions of the moment. Thus my table-top is named square, after 
 but one of an infinite number of retinal sensations which it 
 yields, the rest of them being sensations of two acute and two 
 obtuse angles; but I call the latter perspective views, and the 
 four right angles the true form of the table, and erect the at- 
 tribute squareness into the table's essence, for aesthetic reasons 
 of my own. In like manner, the real form of the circle is deemed 
 to be the sensation it gives when the line of vision is perpendicu- 
 lar to its centre all its other sensations are signs of this sensa- 
 tion. The real sound of the cannon is the sensation it makes 
 when the ear is close by. The real color of the brick is the sensa- 
 tion it gives when the eye looks squarely at it from a near point, 
 out of the sunshine and yet not in the gloom ; under other cir- 
 cumstances it gives us other color-sensations which are but 
 signs of this we then see it look pinker or bluer than it 
 really is. The reader knows no object which he does not repre- 
 sent to himself by preference as in some typical attitude, of 
 some normal size, at some characteristic distance, of some stan- 
 dard tint, etc., etc. But all these essential characteristics, 
 which together form for us the genuine objectivity of the thing 
 and are contrasted with what we call the subjective sensations 
 it may yield us at a given moment, are mere sensations like the 
 latter. The mind chooses to suit itself, and decides what par- 
 ticular sensation shall be held more real and valid than all the 
 rest.
 
 PSYCHOLOGY 653 
 
 Next, in a world of objects thus individualized by our mind's 
 selective industry, what is called our ' experience ' is almost 
 entirely determined by our habits of attention. A thing may be 
 present to a man a hundred times, but if he presistently fails to 
 notice it, it cannot be said to enter into his experience. We 
 are all seeing flies, moths, and beetles by the thousand, but to 
 whom, save an entomologist, do they say anything distinct? 
 On the other hand, a thing met only once in a lifetime may leave 
 an indelible experience in the memory. Let four men make a 
 tour in Europe. One will bring home only picturesque impres- 
 sions costumes and colors, parks and views and works of 
 architecture, pictures and statues. To another all this will be 
 non-existent; and distances and prices, populations and drain- 
 age-arrangements, door- and window-fastenings, and other 
 useful statistics will take their place. A third will give a rich 
 account of the theatres, restaurants, and public halls, and 
 naught beside; whilst the fourth will perhaps have been so 
 wrapped in his own subjective broodings as to be able to tell 
 little more than a few names of places through which he passed. 
 Each has selected, out of the same mass of presented objects, 
 those which suited his private interest and has made his experi- 
 ence thereby. 
 
 If now, leaving the empirical combination of objects, we ask 
 how the mind proceeds rationally to connect them, we find 
 selection again to be omnipotent. In a future chapter we shall 
 see that all Reasoning depends on the ability of the mind to 
 break up the totality of the phenomenon reasoned about, into 
 parts, and to pick out from among these the particular one 
 which, in the given emergency, may lead to the proper conclu- 
 sion. The man of genius is he who will always stick in his bill 
 at the right point, and bring it out with the right element - 
 ' reason ' if the emergency be theoretical, ' means ' if it be 
 practical transfixed upon it. 
 
 If now we pass to the aesthetic department, our law is still 
 more obvious. The artist notoriously selects his items, rejecting 
 all tones, colors, shapes, which do not harmonize with each 
 other and with the main purpose of his work. That unity, bar-
 
 654 WILLIAM JAMES 
 
 mony, ' convergence of characters,' as M. Taine calls it, which 
 gives to works of art their superiority over works of nature, is 
 wholly due to elimination. Any natural subject will do, if the 
 artist has wit enough to pounce upon some one feature of it as 
 characteristic, and suppress all merely accidental items which 
 do not harmonize with this. 
 
 Ascending still, higher, we reach the plane of Ethics, where 
 choice reigns notoriously supreme. An act has no ethical qual- 
 ity whatever unless it be chosen out of several all equally pos- 
 sible. To sustain the arguments for the good course and keep 
 them ever before us, to stifle our longing for more flowery ways, 
 to keep the foot unflinchingly on the arduous path, these are 
 characteristic ethical energies. But more than these; for these 
 but deal with the means of compassing interests already felt by 
 the man to be supreme. The ethical energy par excellence has to 
 go farther and choose which interest out of several, equally co- 
 ercive, shall become supreme. The issue here is of the utmost 
 pregnancy, for it decides a man's entire career. When he de- 
 bates, Shall I commit this crime? choose that profession? ac- 
 cept that office, or marry this fortune? his choice really lies 
 between one of several equally possible future Characters. 
 What he shall become is fixed by the conduct of this moment. 
 Schopenhauer, who enforces his determinism by the argument 
 that with a given fixed character only one reaction is possible 
 under given circumstances, forgets that, in these critical ethical 
 moments, what consciously seems to be in question is the com- 
 plexion of the character itself. The problem with the man is 
 less what act he shall now resolve to do than what being he shall 
 now choose to become. 
 
 Taking human experience in a general way, the choosings of 
 different men are to a great extent the same. The race as a 
 whole largely agrees as to what it shall notice and name; and 
 among the noticed parts we select in much the same way for 
 accentuation and preference, or subordination and dislike. 
 There is, however, one entirely extraordinary case in which no 
 two men ever are known to choose alike. One great splitting 
 of the whole universe into two halves is made by each of us;
 
 PSYCHOLOGY 655 
 
 and for each of us almost all of the interest attaches to one of 
 the halves; but we all draw the line of division between them 
 in a different place. When I say that we all call the two halves 
 by the same names, and that those names are ' me ' and ' not- 
 me ' respectively, it will at once be seen what I mean. The alto- 
 gether unique kind of interest which each human mind feels in 
 those parts of creation which it can call me or mine may be a 
 moral riddle, but it is a fundamental psychological fact. No 
 mind can take the same interest in his neighbor's me as in his 
 own. The neighbor's me falls together with all the rest of things 
 in one foreign mass against which his own me stands out in 
 startling relief. Even the trodden worm, as Lotze somewhere 
 says, contrasts his own suffering self with the whole remaining 
 universe, though he have no clear conception either of himself or 
 of what the universe may be. He is for me a mere part of the 
 world ; for him it is I who am the mere part. Each of us dicho- 
 tomizes the Kosmos in a different place. 
 
 CHAPTER XXIV. EMOTION 1 
 
 Emotions compared with Instincts. An emotion is a tend- 
 ency to feel, and an instinct is a tendency to act, characteristic- 
 ally, when in presence of a certain object in the environment. 
 But the emotions also have their bodily ' expression,' which 
 may involve strong muscular activity (as in fear or anger, for 
 example) ; and it becomes a little hard in many cases to separate 
 the description of the ' emotional ' condition from that of the 
 ' instinctive ' reaction which one and the same object may pro- 
 voke. Shall fear be described in the chapter on Instincts or in 
 that on Emotions? Where shall one describe curiosity, emula- 
 tion, and the like? The answer is quite arbitrary from the scien- 
 tific point of view, and practical convenience may decide. As 
 inner mental conditions, emotions are quite indescribable. 
 Description, moreover, would be superfluous, for the reader 
 
 1 The substance of this chapter first appeared in an article published in 
 Mind in 1884, an d again as a chapter in the author's Principles of Psychology, 
 in 1850.
 
 656 WILLIAM JAMES 
 
 knows already how they feel. Their relations to the objects 
 which prompt them and to the reactions which they provoke 
 are all that one can put down in a book. 
 
 Every object that excites an instinct excites an emotion as 
 well. The only distinction one may draw is that the reaction 
 called emotional terminates in the subject's own body, whilst 
 the reaction called instinctive is apt to go farther and enter 
 into practical relations with the exciting object. In both 
 instinct and emotion the mere memory or imagination of the 
 object may suffice to liberate the excitement. One may even 
 get angrier in thinking over one's insult than one was in receiv- 
 ing it; and melt more over a mother who is dead than one ever 
 did when she was living. In the rest of the chapter I shall use 
 the word object of emotion indifferently to mean one which is 
 physically present or one which is merely thought of. 
 
 The varieties of emotion are innumerable. Anger, fear, love, 
 hate, joy, grief, shame, pride, and their varieties, may be called 
 the coarser emotions, being coupled as they are with relatively 
 strong bodily reverberations. The subtler emotions are the 
 moral, intellectual, and aesthetic feelings, and their bodily reac- 
 tion is usually much less strong. The mere description of the 
 objects, circumstances, and varieties of the different species of 
 emotion may go to any length. Their internal shadings merge 
 endlessly into each other, and have been partly commemorated 
 in language, as, for example, by such synonyms as hatred, 
 antipathy, animosity, resentment, dislike, aversion, malice, 
 spite, revenge, abhorrence, etc., etc. Dictionaries of synonyms 
 have discriminated them, as well as text-books of psychology 
 in fact, many German psychological text-books are nothing 
 but dictionaries of synonyms when it comes to the chapter on 
 Emotion. But there are limits to the profitable elaboration of 
 the obvious, and the result of all this flux is that the merely 
 descriptive literature of the subject, from Descartes down- 
 wards is one of the most tedious parts of psychology. And not 
 only is it tedious, but you feel that its subdivisions are to a 
 great extent either fictitious or unimportant, and that its pre- 
 tences to accuracy are a sham. But unfortunately there is
 
 PSYCHOLOGY 657 
 
 little psychological writing about the emotions which is not 
 merely descriptive. As emotions are described in novels, they 
 interest us, for we are made to share them. We have grown 
 acquainted with the concrete objects and emergencies which 
 call them forth, and any knowing touch of introspection which 
 may grace the page meets with a quick and feeling response. 
 Confessedly literary works of aphoristic philosophy also flash 
 lights into our emotional life, and give us a fitful delight. But 
 as far as the ' scientific psychology ' of the emotions goes, I may 
 have been surfeited by too much reading of classic works on the 
 subject, but I would as lief read verbal descriptions of the shapes 
 of the rocks on a New Hampshire farm as toil through them 
 again. They give one nowhere a central point of view, or a de- 
 ductive or generative principle. They distinguish and refine 
 and specify in infinitum without ever getting on to another 
 logical level. Whereas the beauty of all truly scientific work is 
 to get to ever deeper levels. Is there no way out from this level 
 of individual description in the case of the emotions? I believe 
 there is a way out, if one will only take it. 
 
 The Cause of their Varieties. The trouble with the emo- 
 tions in psychology is that they are regarded too much as abso- 
 lutely individual things. So long as they are set down as so 
 many eternal and sacred psychic entities, like the old immu- 
 table species in natural history, so long all that can be done 
 with them is reverently to catalogue their separate characters, 
 points, and effects. But if we regard them as products of more 
 general causes (as ' species ' are now regarded as products of 
 heredity and variation) , the mere distinguishing and catalogu- 
 ing becomes of subsidiary importance. Having the goose which 
 lays the golden eggs, the description of each egg already laid is 
 a minor matter. I will devote the next few pages to setting 
 forth one very general cause of our emotional feeling, limiting 
 myself in the first instance to what may be called the coarser 
 emotions. 
 
 The feeling, in the coarser emotions, results from the bodily 
 expression. Our natural way of thinking about these coarser 
 emotions is that the mental perception of some fact excites the
 
 658 WILLIAM JAMES 
 
 mental affection called the emotion, and that this latter state 
 of mind gives rise to the bodily expression. My theory, on the 
 contrary, is that the bodily changes follow directly the perception 
 of the exciting fact, and that our feeling of the same changes as 
 they occur is the emotion. Common-sense says, we lose our for- 
 tune, are sorry and weep; we meet a bear, are frightened and 
 run; we are insulted by a rival, are angry and strike. The 
 hypothesis here to be defended says that this order of sequence 
 is incorrect, and the one mental state is not immediately in- 
 duced by the other, that the bodily manifestations must first 
 be interposed between, and that the more rational statement is 
 that we feel sorry because we cry, angry because we strike, 
 afraid because we tremble, and not that we cry, strike, or trem- 
 ble because we are sorry, angry, or fearful, as the case may be. 
 Without the bodily states following on the perception, the lat- 
 ter would be purely cognitive in form, pale, colorless, destitute 
 of emotional warmth. We might then see the bear and judge 
 it best to run, receive the insult and deem it right to strike, but 
 we should not actually feel afraid or angry. 
 
 Stated in this crude way, the hypothesis is pretty sure to 
 meet with immediate disbelief. And yet neither many nor 
 far-fetched considerations are required to mitigate its para- 
 doxical character, and possibly to produce conviction of its 
 truth. 
 
 To begin with, particular perceptions certainly do produce 
 wide-spread bodily effects by a sort of immediate physical influ- 
 ence, antecedent to the arousal of an emotion or emotional idea. 
 In listening to poetry, drama, or heroic narrative we are often 
 surprised at the cutaneous shiver which like a sudden wave 
 flows over us, and at the heart-swelling and the lachrymal 
 effusion that unexpectedly catch us at intervals. In hearing 
 music the same is even more strikingly true. If we abruptly see 
 a dark moving form in the woods, our heart stops beating, and 
 we catch our breath instantly and before any articulate idea of 
 danger can arise. If our friend goes near to the edge of a preci- 
 pice, we get the well-known feeling of ' all-overishness,' and 
 we shrink back, although we positively know him to be safe,
 
 PSYCHOLOGY 659 
 
 and have no distinct imagination of his fall. The writer well 
 remembers his astonishment, when a boy of seven or eight, at 
 fainting when he saw a horse bled. The blood was in a bucket, 
 with a stick in it, and, if memory does not deceive him, he 
 stirred it round and saw it drip from the stick with no feeling 
 save that of childish curiosity. Suddenly the world grew black 
 before his eyes, his ears began to buzz, and he knew no more. 
 He had never heard of the sight of blood producing faintness or 
 sickness, and he had so little repugnance to it, and so little 
 apprehension of any other sort of danger from it, that even at 
 that tender age, as he well remembers, he could not help wonder- 
 ing how the mere physical presence of a pailful of crimson fluid 
 could occasion in him such formidable bodily effects. 
 
 The best proof that the immediate cause of emotion is a 
 physical effect on the nerves is furnished by those pathological 
 cases in which the emotion is objectless. One of the chief merits, 
 in fact, of the view which I propose seems to be that we can so 
 easily formulate by its means pathological cases and normal 
 cases under a common scheme. In every asylum we find exam- 
 ples of absolutely unmotived fear, anger, melancholy, or con- 
 ceit; and others of an equally unmotived apathy which persists 
 in spite of the best of outward reasons why it should give way. 
 In the former cases we must suppose the nervous machinery to 
 be so ' labile ' in some one emotional direction that almost 
 every stimulus (however inappropriate) causes it to upset in 
 that way, and to engender the particular complex of feelings of 
 which the psychic body of the emotion consists. Thus, to take 
 one special instance, if inability to draw deep breath, fluttering 
 of the heart, and that peculiar epigastric change felt as ' pre- 
 cordial anxiety,' with an irresistible tendency to take a some- 
 what crouching attitude and to sit still, and with perhaps other 
 visceral processes not now known, all spontaneously occur to- 
 gether in a certain person, his feeling of their combination is the 
 emotion of dread, and he is the victim of what is known as 
 morbid fear. A friend who has had occasional attacks of this 
 most distressing of all maladies tells me that in his case the 
 whole drama seems to centre about the region of the heart and
 
 660 WILLIAM JAMES 
 
 respiratory apparatus, that his main effort during the attacks 
 is to get control of his inspirations and to slow his heart, and 
 that the moment he attains to breathing deeply and to holding 
 himself erect, the dread, ipso facto, seems to depart. 
 
 The emotion here is nothing but the feeling of a bodily state, 
 and it has a purely bodily cause. 
 
 The next thing to be noticed is this, that every one of the 
 bodily changes, whatsoever it be, is FELT, acutely or obscurely, the 
 moment it occurs. If the reader has never paid attention to this 
 matter, he will be both interested and astonished to learn how 
 many different local bodily feelings he can detect in himself as 
 characteristic of his various emotional moods. It would be per- 
 haps too much to expect him to arrest the tide of any strong 
 gust of passion for the sake of any such curious analysis as this; 
 but he can observe more tranquil states, and that may be 
 assumed here to be true of the greater which is shown to be 
 true of the less. Our whole cubic capacity is sensibly alive; 
 and each morsel of it contributes its pulsations of feeling, dim 
 or sharp, pleasant, painful, or dubious, to that sense of per- 
 sonality that every one of us unfailingly carries with him. It is 
 surprising what little items give accent to these complexes of 
 sensibility. When worried by any slight trouble, one may find 
 that the focus of one's bodily consciousness is the contraction 
 often quite inconsiderable, of the eyes and brows. When mo- 
 mentarily embarrassed, it is something in the pharynx that 
 compels either a swallow, a clearing of the throat, or a slight 
 cough; and so on for as many more instances as might be 
 named. The various permutations of which these organic 
 changes are susceptible make it abstractly possible that no 
 shade of emotion should be without a bodily reverberation as 
 unique, when taken in its totality, as is the mental mood itself. 
 The immense number of parts modified is what makes it so diffi- 
 cult for us to reproduce in cold blood the total and integral 
 expression of any one emotion. We may catch the trick with 
 the voluntary muscles, but fail with the skin, glands, heart, and 
 other viscera. Just as an artificially imitated sneeze lacks some- 
 thing of the reality, so the attempt to imitate grief or enthusi-
 
 PSYCHOLOGY 661 
 
 asm in the absence of its normal instigating cause is apt to be 
 rather ' hollow.' 
 
 I now proceed to urge the vital point of my whole theory, 
 which is this: // we fancy some strong emotion, and then try to 
 abstract from our consciousness of it all the feelings of its bodily 
 symptoms, we find we have nothing left behind, no ' mind-stuff ' 
 out of which the emotion can be constituted, and that a cold and 
 neutral state of intellectual perception is all that remains. It is 
 true that, although most people, when asked, say that their 
 introspection verifies this statement, some persist in saying 
 theirs does not. Many cannot be made to understand the ques- 
 tion. When you beg them to imagine away every feeling of 
 laughter and of tendency to laugh from their consciousness of 
 the ludicrousness of an object, and then to tell you what the 
 feeling of its ludicrousness would be like, whether it be any- 
 thing more than the perception that the object belongs to the 
 class ' funny,' they persist in replying that the thing proposed 
 is a physical impossibility, and that they always must laugh if 
 they see a funny object. Of course the task proposed is not the 
 practical one of seeing a ludicrous object and annihilating one's 
 tendency to laugh. It is the purely speculative one of subtract- 
 ing certain elements of feeling from an emotional state sup- 
 posed to exist in its fulness, and saying what the residual ele- 
 ments are. I cannot help thinking that all who rightly appre- 
 hend this problem will agree with the proposition above laid 
 down. What kind of an emotion of fear would be left if the 
 feeling neither of quickened heart-beats nor of shallow breath- 
 ing, neither of trembling lips nor of weakened limbs, neither of 
 goose-flesh nor of visceral stirrings, were present, it is quite 
 impossible for me to think. Can one fancy the state of rage 
 and picture no ebullition in the chest, no flushing of the face, no 
 dilatation of the nostrils, no clenching of the teeth, no impulse 
 to vigorous action, but in their stead limp muscles, calm 
 breathing, and a placid face? The present writer, for one, cer- 
 tainly cannot. The rage is as completely evaporated as the sens- 
 ation of its so-called manifestations, and the only thing that 
 can possibly be supposed to take its place is some cold-blooded
 
 662 WILLIAM JAMES 
 
 and dispassionate judicial sentence, confined entirely to the 
 intellectual realm, to the effect that a certain person or persons 
 merit chastisement for their sins. In like manner of grief: what 
 would it be without its tears, its sobs, its suffocation of the 
 heart, its pang in the 'breast-bone? A feelingless cognition that 
 certain circumstances are deplorable, and nothing more. 
 Every passion in turn tells the same story. A disembodied 
 human emotion is a sheer nonentity. I do not say that it is a 
 contradiction in the nature of things, or that pure spirits are 
 necessarily condemned to cold intellectual lives; but I say that 
 for us emotion dissociated from all bodily feeling is inconceiv- 
 able. The more closely I scrutinize my states, the more per- 
 suaded I become that whatever ' coarse' affections and passions 
 I have are in very truth constituted by, and made up of, those 
 bodily changes which we ordinarily call their expression or con- 
 sequence; and the more it seems to me that, if I were to become 
 corporeally anaesthetic, I should be excluded from the life of 
 the affections, harsh and tender alike, and drag out an existence 
 of merely cognitive or intellectual form. Such an existence, 
 although it seems to have been the ideal of ancient sages, is too 
 apathetic to be keenly sought after by those born after the 
 revival of the worship of sensibility, a few generations ago. 
 
 Let not this view be called materialistic. It is neither more 
 nor less materialistic than any other view which says that our 
 emotions are conditioned by nervous processes. No reader of 
 this book is likely to rebel against such a saying so long as it is 
 expressed in general terms; and if any one still finds material- 
 ism in the thesis now defended, that must be because of the 
 special processes invoked. They are sensational processes, pro- 
 cesses due to inward currents set up by physical happenings. 
 Such processes have, it is true, always been regarded by the 
 platonizers in psychology as having something peculiarly base 
 about them. But our emotions must always be inwardly what 
 they are, whatever be the physiological ground of their appari- 
 tion. If they are deep, pure, worthy, spiritual facts on any 
 conceivable theory of their physiological source, they remain 
 no less deep, pure, spiritual, and worthy of regard on this
 
 PSYCHOLOGY 663 
 
 present sensational theory. They carry their own inner meas- 
 ure of worth with them; and it is just as logical to use the 
 present theory of the emotions for proving that sensational 
 processes need not be vile and material, as to use their vileness 
 and materiality as a proof that such a theory cannot be true. 
 
 This view explains the great variability of emotion. If such 
 a theory is true, then each emotion is the resultant of a sum of 
 elements, and each element is caused by a physiological pro- 
 cess of a sort already well known. The elements are all organic 
 changes, and each of them is the reflex effect of the exciting 
 object. Definite questions now immediately arise questions 
 very different from those which were the only possible ones 
 without this view. Those questions were of classification: 
 " Which are the proper genera of emotion, and which the spe- 
 cies under each? " or of description: " By what expression 
 is each emotion characterized? " The questions now are causal : 
 "Just what changes does this object and what changes does that 
 object excite? " and " How come they to excite these particular 
 changes and not others? " We step from a superficial to a deep 
 order of inquiry. Classification and description are the lowest 
 stage of science. They sink into the background the moment 
 questions of causation are formulated, and remain important 
 only so far as they facilitate our answering these. Now the 
 moment an emotion is causally accounted for, as the arousal 
 by an object of a lot of reflex acts which are forthwith felt, we 
 immediately see why there is no limit to the number of possible dif- 
 ferent emotions which may exist, and why the emotions of different 
 individuals may "vary indefinitely, both as to their constitution 
 and as to the objects which call them forth. For there is nothing 
 sacramental or eternally fixed in reflex action. Any sort of reflex 
 effect is possible, and reflexes actually vary indefinitely, as we 
 know. 
 
 In short, any classification of the emotions is seen to be as true 
 and as ' natural ' as any other, if it only serves some purpose; 
 and such a question as " What is the ' real ' or ' typical ' ex- 
 pression of anger, or fear? " is seen to have no objective mean- 
 ing at all. Instead of it we now have the question as to how
 
 664 WILLIAM JAMES 
 
 any given ' expression ' of anger or fear may have come to 
 exist; and that is a- real question of physiological mechanics on 
 the one hand, and of history on the other, which (like all real 
 questions) is in essence answerable, although the answer may 
 be hard to find. On a later page I shall mention the attempts to 
 answer it which have been made. 
 
 A Corollary verified. If our theory be true, a necessary 
 corollary of it ought to be this: that any voluntary and cold- 
 blooded arousal of the so-called manifestations of a special 
 emotion should give us the emotion itself. Now within the lim- 
 its in which it can be verified, experience corroborates rather 
 than disproves this inference. Everyone knows how panic is 
 increased by flight, and how the giving way to the symptoms of 
 grief or anger increases those passions themselves. Each fit of 
 sobbing makes the sorrow more acute, and calls forth another 
 fit stronger still, until at last repose only ensues with lassitude 
 and with the apparent exhaustion of the machinery. In rage, 
 it is notorious how we ' work ourselves up ' to a climax by 
 repeated outbreaks of expression. Refuse to express a passion, 
 and it dies. Count ten before venting your anger, and its occa- 
 sion seems ridiculous. Whistling to keep up courage is no mere 
 figure of speech. On the other hand, sit all day in a moping 
 posture, sigh, and reply to everything with a dismal Voice, and 
 your melancholy lingers. There is no more valuable precept in 
 moral education than this, as all who have experience know 
 if we wish to conquer undesirable emotional tendencies in our- 
 selves, we must assiduously, and in the first instance cold- 
 bloodedly, go through the outward movements of those contrary 
 dispositions which we prefer to cultivate. The reward of per- 
 sistency will infallibly come, in the fading out of the sullenness 
 or depression, and the advent of real cheerfulness and kindli- 
 ness in their stead. Smooth the brow, brighten the eye, con- 
 tract the dorsal rather than the ventral aspect of the frame, and 
 speak in a major key, pass the genial compliment, and your 
 heart must be frigid indeed if it do not gradually thaw! 
 
 Against this it is to be said that many actors who perfectly 
 mimic the outward appearances of emotion in face, gait, and
 
 PSYCHOLOGY 665 
 
 voice declare that they feel no emotion at all. Others, however, 
 according to Mr. Wm. Archer, who has made a very instructive 
 statistical inquiry among them, say that the emotion of the 
 part masters them whenever they play it well. The explanation 
 for the discrepancy amongst actors is probably simple. The 
 visceral and organic part of the expression can be suppressed in 
 some men, but not in others, and on this it must be that the 
 chief part of the felt emotion depends. Those actors who feel 
 the emotion are probably unable, those who are inwardly cold 
 are probably able, to affect the dissociation in a complete way. 
 
 An Objection replied to. It may be objected to the general 
 theory which I maintain that stopping the expression of an 
 emotion often makes it worse. The funniness becomes quite 
 excruciating when we are forbidden by the situation to laugh, 
 and anger pent in by fear turns into tenfold hate. Expressing 
 either emotion freely, however, gives relief. 
 
 This objection is more specious than real. During the expres- 
 sion the emotion is always felt. After it, the centres having 
 normally discharged themselves, we feel it no more. But where 
 the facial part of the discharge is suppressed the thoracic and 
 visceral may be all the more violent and persistent, as in sup- 
 pressed laughter; or the original emotion may be changed, by 
 the combination of the provoking object with the restraining 
 pressure, into another emotion altogether, in which different and 
 possibly profounder organic disturbance occurs. If I would kill 
 my enemy but dare not, my emotion is surely altogether other 
 than that which would possess me if I let my anger explode. - 
 On the whole, therefore, this objection has no weight. 
 
 The Subtler Emotions. In the aesthetic emotions the 
 bodily reverberation and the feeling may both be faint. A 'con- 
 noisseur is apt to judge a work of art dryly and intellectually, 
 and with no bodily thrill. On the other hand, works of art may 
 arouse intense emotion; and whenever they do so, the experi- 
 ence is completely covered by the terms of our theory. Our 
 theory requires that incoming currents be the basis of emotion. 
 But, whether secondary organic reverberations be or be not 
 aroused by it, the perception of a work of art (music, decoration,
 
 666 WILLIAM JAMES 
 
 etc.) is always in the first instance at any rate an affair of in- 
 coming currents. The work is an object of sensation; and, the 
 perception, of an object of sensation being a ' coarse ' or vivid 
 experience, what pleasure goes with it will partake of the 
 ' coarse ' or vivid form. 
 
 That there may be subtle pleasure too, I do not deny. In 
 other words, there may be purely cerebral emotion, independ- 
 ent of all currents from outside. Such feelings as moral satisfac- 
 tion, thankfulness, curiosity, relief at getting a problem solved, 
 may be of this sort. But the thinness and paleness of these feel- 
 ings, when unmixed with bodily effects, is in very striking con- 
 trast to the coarser emotions. In all sentimental and impression- 
 able people the bodily effects mix in : the voice breaks and the 
 eyes moisten when the moral truth is felt, etc. Wherever there 
 is anything like rapture, however intellectual its ground, we find 
 these secondary processes ensue. Unless we actually laugh at 
 the neatness of the demonstration or witticism ; unless we thrill 
 at the case of justice, or tingle at the act of magnanimity, our 
 state of mind can hardly be called emotional at all. It is in fact 
 a mere intellectual perception of how certain things are to be 
 called neat, right, witty, generous, and the like. Such a 
 judicial state of mind as this is to be classed among cognitive 
 rather than among emotional acts. 
 
 Description of Fear. For the reasons given on p. 656, 1 will 
 append no inventory or classification of emotions or description 
 of their symptoms. The reader has practically almost all the 
 facts in his own hand. As an example, however, of the best 
 sort of descriptive work on the symptoms, I will quote Darwin's 
 account of them in fear. 
 
 11 Fear is often preceded by astonishment, and is so far akin 
 to it that both lead to the senses of sight and hearing being 
 instantly aroused. In both cases the eyes and mouth are widely 
 opened and the eyebrows raised. The frightened man at first 
 stands like a statue, motionless and breathless, or crouches 
 down as if instinctively to escape observation. The heart beats 
 quickly and violently, so that it palpitates or knocks against 
 the ribs; but it is very doubtful if it then works more efficiently
 
 PSYCHOLOGY 667 
 
 than usual, so as to send a greater supply of blood to all parts of 
 the body; for the skin instantly becomes pale as during incipi- 
 ent faintness. This paleness of the surface, however, is pro- 
 bably in large part, or is exclusively, due to the vaso-motor 
 centre being affected in such manner as to cause the contrac- 
 tion of the small arteries of the skin. That the skin is much 
 affected under the sense of great fear, we see in the marvellous 
 manner in which perspiration immediately exudes from it. 
 This exudation is all the more remarkable, as the surface is 
 then cold, and hence the term, a cold sweat; whereas the 
 sudorific glands are properly excited into action when the sur- 
 face is heated. The hairs also on the skin stand erect, and the 
 superficial muscles shiver. In connection with the disturbed 
 action of the heart the breathing is hurried. The salivary 
 glands act imperfectly; the mouth becomes dry and is often 
 opened and shut. I have also noticed that under slight fear 
 there is strong tendency to yawn. One of the best marked symp- 
 toms is the trembling of all the muscles of the body; and this is 
 often first seen in the lips. From this cause, and from the dry- 
 ness of the mouth, the voice becomes husky or indistinct or 
 may altogether fail. ' Obstupui steteruntque conuz, et vox fauci- 
 bus hcesit.' ... As fear increases into an agony of terror, we 
 behold, as under all violent emotions, diversified results. The 
 heart beats wildly or must fail to act and faintness ensue; there 
 is a death-like pallor; the breathing is labored; the wings of the 
 nostrils are widely dilated; there is a gasping and convulsive 
 motion of the lips, a tremor on the hollow cheek, a gulping and 
 catching of the throat; the uncovered and protruding eyeballs 
 are fixed on the object of terror ; or they may roll restlessly from 
 side to side, hue illuc volens oculos totumque pererrat. The pupils 
 are said to be enormously dilated. All the muscles of the body 
 may become rigid or may be thrown into convulsive move- 
 ments. The hands are alternately clenched and opened, often 
 with a twitching movement. The arms may be protruded as if 
 to avert some dreadful danger, or may be thrown wildly over 
 the head. The Rev. Mr. Hagenauer has seen this latter action 
 in a terrified Australian. In other cases there is a sudden and
 
 668 WILLIAM JAMES 
 
 uncontrollable tendency to headlong flight; and so strong is this 
 that the boldest soldiers may be seized with a sudden panic." l 
 
 Genesis of the Emotional Reactions. How come the vari- 
 ous objects which excite emotion to produce such special and 
 different bodily effects? This question was not asked till quite 
 recently, but already some interesting suggestions towards 
 answering it have been made. 
 
 Some movements of expression can be accounted for as 
 weakened repetitions of movements which formerly (when they 
 were stronger) were of utility to the subject. Others are similarly 
 weakened repetitions of movements which under other condi- 
 tions were physiologically necessary concomitants of the useful 
 movements. Of the latter reactions the respiratory disturbances 
 in anger and fear might be taken as examples organic reminis- 
 cences, as it were, reverberations in imagination of the blowings 
 of the man making a series of combative efforts, of the pantings 
 of one in precipitate flight. Such at least is a suggestion made by 
 Mr. Spencer which has found approval. And he also was the 
 first, so far as I know, to suggest that other movements in 
 anger and fear could be explained by the nascent excitation of 
 formerly useful acts. 
 
 " To have in a slight degree," he says, " such psychical states 
 as accompany the reception of wounds, and are experienced 
 during flight, is to be in a state of what we call fear. And to 
 have in a slight degree such psychical states as the processes 
 of catching, killing, and eating imply, is to have the desires to 
 catch, kill, and eat. That the propensities to the acts are no- 
 thing else than nascent excitations of the psychical state in- 
 volved in the acts, is proved by the natural language of the 
 propensities. Fear, when strong, expresses itself in cries, in 
 efforts to escape, in palpitations, in tremblings; and these are 
 just the manifestations that go along with an actual suffering 
 of the evil feared. The destructive passion is shown in a gen- 
 eral tension of the muscular system, in gnashing of teeth and 
 protrusion of the claws, in dilated eyes and nostrils in growls; 
 and these are weaker forms of the actions that accompany the 
 1 Origin of the Emotions (N. Y. ed.), p. 292.
 
 PSYCHOLOGY 669 
 
 killing of prey. To such objective evidences every one can add 
 subjective evidences. Every one can testify that the psychical 
 state called fear consists of mental representations of certain 
 painful results; and that the one called anger consists of mental 
 representations of the actions and impressions which would 
 occur while inflicting some kind of pain." 
 
 The principle of revival, in weakened form, of reactions useful 
 in more violent dealings with the object inspiring the emotion, has 
 found many applications. So slight a symptom as the snarl or 
 sneer, the one-sided uncovering of the upper teeth, is ac- 
 counted for by Darwin as a survival from the time when our 
 ancestors had large canines, and unfleshed them (as dogs now 
 do) for attack. Similarly the raising of the eyebrows in outward 
 attention, the opening of the mouth in astonishment, come, 
 according to the same author, from the utility of these move- 
 ments in extreme cases. The raising of the eyebrows goes with 
 the opening of the eye for better vision; the opening of the 
 mouth with the intensest listening, and with the rapid catching 
 of the breath which precedes muscular effort. The distention 
 of the nostrils in anger is interpreted by Spencer as an echo of 
 the way in which our ancestors had to breathe when, during 
 combat, their " mouth was filled up by a part of an antagonist's 
 body that had been seized " (!). The trembling of fear is sup- 
 posed by Mantegazza to be for the sake of warming the blood ( 
 The reddening of the face and neck is called by Wundt a com- 
 pensatory arrangement for relieving the brain of the blood- 
 pressure which the simultaneous excitement of the heart brings 
 with it. The effusion of tears is explained both by this author 
 and by Darwin to be a blood-withdrawing agency of a similar 
 sort. The contraction of the muscles around the eyes, of which 
 the primitive use is to protect those organs from being too much 
 gorged with blood during the screaming fits of infancy, survives 
 in adult life in the shape of the frown, which instantly comes 
 over the brow when anything difficult or displeasing presents 
 itself either to thought or action. 
 
 " As the habit of contracting the brows has been followed 
 by infants during innumerable generations, at the commence-
 
 670 WILLIAM JAMES 
 
 ment of every crying or screaming fit," says Darwin, " it has 
 become firmly associated with the incipient sense of some- 
 thing distressing or disagreeable. Hence, under similar cir- 
 cumstances, it would be apt to be continued during maturity, 
 although never then developed, into a crying fit. Screaming 
 or weeping begins to be voluntarily restrained at an early 
 period of life, whereas frowning is hardly ever restrained at any 
 age." 
 
 Another principle, to which Darwin perhaps hardly does 
 sufficient justice, may be called the principle of reacting 
 similarly to analogous-feeling stimuli. There is a whole voca- 
 bulary of descriptive adjectives common to impressions belong- 
 ing to different sensible spheres experiences of all classes are 
 sweet, impressions of all classes rich or solid, sensations of all 
 classes sharp. Wundt and Piderit accordingly explain many of 
 our most expressive reactions upon moral causes as symbolic 
 gustatory movements. As soon as any experience arises which 
 has an affinity with the feeling of sweet, or bitter, or sour, the 
 same movements are executed which would result from the 
 taste in point. " All the states of mind which language desig- 
 nates by the metaphors bitter, harsh, sweet, combine them- 
 selves, therefore, with the corresponding mimetic movements 
 of the mouth." Certainly the emotions of disgust and satisfac- 
 tion do express themselves in this mimetic way. Disgust is an 
 incipent regurgitation or retching, limiting its expression often 
 to the grimace of the lips and nose ; satisfaction goes with a suck- 
 ing smile, or tasting motion of the lips. The ordinary gesture of 
 negation among us, moving the head about its axis from side 
 to side is a reaction originally used by babies to keep disa- 
 greeables from getting into their mouth, and may be observed 
 in perfection in any nursery. It is now evoked where the stimu- 
 lus is only an unwelcome idea. Similarly the nod forward in 
 affirmation is after the analogy of taking food into the mouth. 
 The connection of the expression of moral or social disdain or 
 dislike, especially in women, with movements having a per- 
 fectly definite original olfactory function, is too obvious for
 
 PSYCHOLOGY 671 
 
 comment. Winking is the effect of any threatening surprise, not 
 only of what puts the eyes in danger; and a momentary aver- 
 sion of the eyes is very apt to be one's first symptom of response 
 to an unexpectedly unwelcome proposition. These may suf- 
 fice as examples of movements expressive from analogy. 
 
 But if certain of our emotional reactions can be explained 
 by the two principles invoked and the reader will himself 
 have felt how conjectural and fallible in some of the instances 
 the explanation is there remain many reactions which can- 
 not so be explained at all, and these we must write down for the 
 present as purely idiopathic effects of the stimulus. Amongst 
 them are the effects on the viscera and internal glands, the dry- 
 ness of the mouth and diarrhoea and nausea of fear, the liver- 
 disturbances which sometimes produce jaundice after excessive 
 rage, the urinary secretion of sanguine excitement, and the 
 bladder-contraction of apprehension, the gaping of expectancy, 
 the ' lump in the throat ' of grief, the tickling there and the 
 swallowing of embarrassment, the ' precordial anxiety ' of 
 dread, the changes in the pupil, the various sweatings of the 
 skin, cold or hot, local or general, and its flushings, together 
 with other symptoms which probably exist but are too hidden 
 to have been noticed or named. Trembling, which is found in 
 many excitements besides that of terror, is, pace Mr. Spencer 
 and Sig. Mantegazza, quite pathological. So are terror's other 
 strong symptoms: they are harmful to the creature who pre- 
 sents them. In an organism as complex as the nervous system 
 there must be many incidental reactions which would never 
 themselves have been evolved independently, for any utility 
 they might possess. Sea-sickness, ticklishness, shyness, the love 
 of music, of the various intoxicants, nay, the entire aesthetic 
 life of man, must be traced to this accidental origin. It would 
 be foolish to suppose that none of the reactions called emo- 
 tional could have arisen in this gwasi-accidental way.
 
 CARL GEORG LANGE 
 
 (1834-1900) 
 
 THE EMOTIONS 
 
 Translated from the German* of H. Kurella by 
 BENJAMIN RAND 
 
 THE MECHANISM OF THE EMOTIONS 
 
 WE approach now the question which possesses a vital in- 
 terest from the psycho-physiological standpoint, and for that 
 reason forms the centre of this investigation. The question 
 concerns the nature of the relation between the emotions and 
 their accompanying bodily expressions. 
 
 Heretofore I have constantly used phrases, though under 
 protest, such as " the physiological phenomena occasioned by 
 the emotions, " or " the physiological phenomena which accom- 
 pany emotion," etc. I have employed provisionally these cus- 
 tomary expressions for the relation in question in order to be 
 understood. Strangely enough up to the present time this 
 relation never has been in any way accurately, defined. I know 
 of no attempt to determine its exact nature. The matter is very 
 simple in the popular conception. Here emotions are entities, 
 substances, forces, daemons, which seize man and produce in 
 him bodily as well as mental manifestations: "grief seized 
 me," " a joy came to me," " anger controlled me," " fear over- 
 whelmed me," etc. 
 
 As often happens in popular and sometimes even in scientific 
 psychology, this conception has rather a metaphorical than an 
 explicative value. Modern psychology would scarcely adopt it, 
 
 * C. Lange Om Sindsbevaegelser. Kjobenhavn, 1885. Translated here 
 from C. Lange's Ueber Gemiithsbewegungen. Eine psycho-physiologische Studie. 
 Uebersetzt von H. Kurella, Leipzig, 1887.
 
 THE EMOTIONS 673 
 
 if it could offer in its place any more comprehensible or exact 
 explanation. Most modern authors in the domain of scientific 
 psychology do not enter 1 at all into this question. They ap- 
 pear almost deliberately to pass it over in silence, in order pro- 
 bably from the lack of a physiological explanation not to have 
 recourse to the mysterious language of speculative psychology. 
 Indeed one can say that scientific psychology also shares the 
 theory, that the emotions induce and determine the accom- 
 panying bodily expressions. But as to what emotions strictly 
 are, that they can have such power over the body, one seeks, 
 I think, in vain for any explanation in the whole of modern 
 psychology. 
 
 If we desire a clear understanding of the relation here dis- 
 cussed, we must, as it appears to me, formulate the problem 
 approximately in the following way. We have in every emo- 
 tion as certain and manifest factors: (i) a cause, a sense 
 impression, which acts as a rule by the aid of memory, or of an 
 associated idea; and thereafter (2) an effect, namely, the 
 previously discussed vasomotor changes, and further, issuing 
 from them, the changes in the bodily and mental functions. 
 
 The question now arises : 
 
 What lies between these two factors? Is there anything at 
 all? If I begin to tremble because I am threatened with a 
 loaded pistol, does first a psychical process occur in me, does 
 terror arise, and is that what causes my trembling, palpita- 
 tion of the heart, and confusion of thought; or are these bodily 
 phenomena produced directly by the terrifying cause, so that 
 the emotion consists exclusively of the functional disturbances 
 in my body? 
 
 The answer to this question is, as one easily perceives, not 
 merely of decisive significance for the psychology of the emo- 
 tions; but also of the greatest practical significance for any 
 physician, who has to do with the pathological results of vio- 
 lent emotions. 
 
 The current opinion, as already remarked, amounts to the 
 
 1 The external movement springs always from the inner, the emotion. Wundt's 
 Ueber den Ausdruck der Gemuthsbewegungen. Deutsche Rundschau, April, 1877.
 
 674 CARL GEORG LANGE 
 
 statement, that the immediate effect of a process followed by 
 an emotion is of a purely psychical nature, (therefore, either 
 the creation of a new mental force, or the modification of a pre- 
 vious mental state). Furthermore, it affirms, that this event in 
 the soul is the actual emotion, the true joy, sorrow, etc. ; whereas 
 the bodily phenomena are only subsidiary phenomena, which 
 indeed are never lacking, but are nevertheless in and of them- 
 selves wholly unessential. 
 
 The purely psychical emotion is an hypothesis, and like every 
 hypothesis, has its justification only if it fulfils two conditions: 
 namely, (i) to explain the phenomena for which it is pro- 
 pounded, and (2) that it be necessary for the explanation of 
 these phenomena. 
 
 Respecting the first of these conditions, the hypothesis in 
 question has just as easy a task as all the metaphysical hy- 
 potheses in general have. Without being restricted by objec- 
 tions of experience, one can elaborate them at pleasure, attribut- 
 ing to them any quality or power, and without further difficulty 
 they perform every service that is required of them. But can 
 psychical terror explain why one grows pale, or why one trem- 
 bles? Although we do not understand the explanation, we are 
 still free to assume it, and we are accustomed to be therewith 
 content. 
 
 If the hypothesis of the psychical nature of the emotions is 
 accordingly unassailable at this point, (indeed more because it 
 escapes, than because it stands criticism,) the question arises, 
 whether it fulfils the second condition? Is it indispensable for 
 the explanation of the group of phenomena which we call emo- 
 tions? Can these phenomena be understood without its aid? 
 
 Whoever would make clear to some one who has grown up 
 with the common idea upon this subject, that if he is frightened 
 his terror is only a perception of change in his body, would prob- 
 ably encounter the following objection: "Any such assump- 
 tion of this relation is decisively contradicted by personal expe- 
 rience, since we have in terror, as in every emotion, a perfectly 
 distinct sensation of a peculiar change, or of a definite, psychical 
 state, wholly independent of anything bodily."
 
 THE EMOTIONS 675 
 
 I can readily understand, that this objection has very great 
 significance for the majority, and is difficult to overcome. 
 Nevertheless it has of course in and of itself not the least value. 
 
 We ha ve in fact no absolute and immediate means of determin- 
 ing whether a sensation is of a psychical or bodily character. 
 Furthermore, no one is able to indicate the difference between 
 psychical and somatic feelings. Whoever speaks of a psychical 
 impression does so indeed solely upon the basis of a theory, 
 and not upon an immediate perception. Without doubt, the 
 mother who sorrows over her dead child would resist, pro- 
 bably even become indignant, if anyone were to say to her, 
 that what she feels, is the exhaustion and inertness of her 
 muscles, the numbness in her bloodless skin, the lack of mental 
 power for clear and rapid thought l all of which is made clear 
 by the idea of the cause of these phenomena. There is no reason, 
 however, for her to be indignant, for her feeling is just as strong, 
 as deep and pure, whether it springs from the one, or the other 
 source. But it cannot exist without its bodily attributes. 
 
 If from one terrified the accompanying bodily symptoms are 
 removed, the pulse permitted to beat quietly, the glance to 
 become firm, the color natural, the movements rapid and 
 secure, the speech strong, the thoughts clear, what is there 
 left of his terror? 
 
 If we cannot rely, therefore, in this question upon the testi- 
 mony of personal experience, because it is here incompetent, 
 the matter is thereby naturally not yet explained. If the 
 hypothesis of psychical emotions be not made necessary by 
 subjective experience, it may nevertheless be requisite if with- 
 out it one cannot perhaps understand how the bodily man- 
 ifestations of the emotions come into existence. 
 
 We have consequently first to investigate, whether the bodily 
 manifestations of the emotions can come into existence in 
 
 1 I will not be deterred by the fact that it will probably be objected that one 
 can feel pure psychical grief, joy, etc. if the emotion is not strong enough to 
 lead to bodily symptoms. Such a supposition naturally rests only upon insuffi- 
 cient observation, or because one regards purely subjective sensations those 
 of lightness or pressure, of strength or weakness as psychical.
 
 676 CARL GEORG LANGE 
 
 purely bodily ways. If that is the case, the necessity of the 
 psychical hypothesis is thereby removed. 
 
 In fact, it is not difficult to show from every day experience, 
 which establishes and constantly verifies the truth, that emo- 
 tions can be produced by many causes, which have nothing to 
 do with movements of the mind; as on the other hand, that they 
 can equally as well be checked and subdued by purely bodily 
 means. It is known, though without clear consciousness of the 
 true relation of things, that our entire mode of existence, our 
 daily dietetics, has been formed during the course of genera- 
 tions essentially with the aim to promote the agreeable emo- 
 tions, and to lessen or entirely to remove the painful. I will 
 merely cite a single example, and that will serve to recall others. 
 It is one of the oldest experiences of mankind "that wine maketh 
 glad the heart of man; " and the power of spirituous beverages 
 to combat the closely related states of grief and fear, and to 
 replace them with joy and courage, has found an application, 
 which is in and for itself natural enough, and would be uncondi- 
 tionally beneficial if the means did not possess in addition still 
 other effects. 
 
 We all understand why Jeppe * drinks. It is because he will 
 escape thereby from his conjugal troubles, and his fear of the 
 master Erich. He will sing again, and recall the happy time 
 when he was "in the militia." The glass makes him jovial and 
 courageous, without the addition of a single pleasing or enliv- 
 ening impression which could have any direct effect upon his 
 mind, and without in the least forgetting his troubles or his 
 enemies. All he wants is the influence of wine to view them in 
 a manner different from the customary. He desires to impress 
 his importance upon the sexton, and for once to chastise his wife. 
 The alcohol has excited his vasomotor apparatus, has caused 
 his heart to beat more rapidly and strongly, has enlarged his 
 capillary ducts and thereby heightened his voluntary innerva- 
 tions, and as a consequence, he talks loudly, sings, and blusters, 
 instead of lingering about, whimpering, and whining on the 
 public way. He has the feeling of warmth, airiness, and 
 1 Jeppe am Berge, a character in the classical comedy of Holberg.
 
 THE EMOTIONS 677 
 
 strength, in place of his customary limpness and incapacity. 
 His dull brain awakes again to new life by the quick circulation 
 of blood, the thoughts come in a rush, old memories revive and 
 displace the wonted feeling of his daily misery. And all this 
 is due merely to a "peg" of spirits, the effect of which upon the 
 circulation we can understand, and which has no need of the 
 intervention of the mind to act upon the vasomotor centre. 
 
 All those who drink spirits have an experience of a similar 
 nature to Jeppe's, and thus we have it in general among the 
 means of enjoyment, in addition to the many arrangements 
 that we make to procure for ourselves comfort and well being. 
 So long as we remain within the easy and customary routine of 
 daily life, the connection between our emotional states and 
 material influences, (e.g., nutrition), naturally comes only rarely 
 into the foreground. The relation is otherwise in the enjoy- 
 ment of certain substances, which act upon the body so power- 
 fully that they are employed like drugs, or are ranked under 
 the category of poisons. Thus it is known that the eating of 
 certain fungi, especially the fly agaric, can produce the most 
 violent paroxysms of fury, and of violence. It has been conjec- 
 tured that our warlike ancestors used such means to create the 
 right mood for martial enterprises; therefore entirely similar to 
 the way, in which one to-day drinks spirits to "revive cour- 
 age." Fits of temper also often follow the partaking of hashish 
 (indian hemp), which, ordinarily however like alcohol and 
 opium, evokes a vivacious disposition, even outbursts of 
 unbounded merriment. 
 
 Certain emetics, as ipecacuanha and tartar emetic, produce 
 a feeling of depression, which oftentimes resembles fear, some- 
 times also grief, and like these emotions is accompanied by 
 symptoms of collapse. 
 
 If emotional states can be precipitated by the enjoyment of 
 certain substances, or in other purely bodily ways, it follows 
 that one can combat and abate painful emotions in the same 
 way. If spirits or opium produce joy, they are an antidote 
 for sorrow. 
 
 The power of cold water to subdue temper and outbreaks of
 
 678 CARL GEORG LANGE 
 
 passion finds occasionally a practical use, and can, when ap- 
 plied to the body, scarcely act directly upon the mind; but so 
 much the more does it act upon the vasomotor functions. By 
 the agency of a medicine, the well-known bromide of potas- 
 sium, which causes paralysis of the vasomotor apparatus, we 
 have it in our power not only to allay fear and anxiety, and 
 similar uncomfortable emotions, but also, if we wish, to cause a 
 perfectly apathetic condition, in which the individual is even 
 as little able to become festive or sad, as anxious and angry, 
 simply because the vasomotor functions are suspended. 
 
 If the theory of the nature of the emotions here advocated, 
 is well founded, we may in a general way expect that every 
 action connected with functional changes of the vasomotor 
 system must also have an emotional expression. Naturally we 
 should not expect that emotions originated in this way would 
 conform in every way with the phenomenon for which we com- 
 monly reserve this designation; the differences in the causes na- 
 turally must find expression in this domain through differences 
 in the effects. The different psychical causes have also in reality 
 effects which are not at all congruous. The fear of ghosts is not 
 imagined in the same form as fear of the bullets of an enemy. 
 Nevertheless, the similarity in many cases between the bodily 
 and the psychically conditioned emotions has been sufficiently 
 striking to force itself upon immediate apprehension, as the 
 many linguistic designations clearly prove. Thus in all languages 
 there is one and the same expression for mental and bodily 
 pain. We have recognized their great physiological similarity, 
 although the marked phenomenon of bodily pain, namely the 
 subjective sensation in consequence of the transmission of the 
 peripheral stimulus to the sensorium, is lacking in the case of 
 mental pain. The cause of similarity of the physical to the 
 emotional pain is the reflex innervation of the vascular nerves, a 
 normal effect of every rather strong stimulation of the sensitive 
 nerves. 
 
 The term shudder, in this way, is the common designation in 
 speech for the phenomena arising from the sudden effects of 
 cold upon the skin, and also from terrifying impressions. That
 
 THE EMOTIONS 679 
 
 the na'ive intelligence recognizes no distinction between the 
 shuddering due to emotional, and that due to purely bodily 
 causes, we perceive in the fairy tale of the youth, who went 
 forth in order to find out what shuddering was, and who after 
 seeking in vain to discover it in the company of the dead and of 
 ghosts, had his wish fulfilled when he was thrown from his bed 
 into a tub of ice cold water, which produced a more painful 
 effect upon his vasomotor apparatus than the sight of corpses, 
 and of ghosts. 
 
 The designation feverish for the man who is very impatient, 
 likewise shows, that we have been impressed by the similarity 
 which exists between the light symptoms of fever with their 
 vasomotor disturbances, and those bodily conditions which 
 are produced by disquieting expectations. 
 
 As already remarked, I shall not enter in this small treatise 
 more minutely into the large question concerning the relation 
 of the emotions with the corresponding pathological states, or 
 with mental and bodily diseases. 
 
 But there exists in this connection a relation which I cannot 
 pass entirely by, because it throws much light upon the question 
 with which we are here occupied, that is, the necessity of the 
 hypothesis of purely psychical emotions. If there is anything 
 that in a striking way can prove the superfluous nature of this 
 hypothesis, it is certainly the circumstance that the emotions 
 arise without being evoked by any external impression, or by 
 any occurrence which acts upon our mental life, or by any mem- 
 ory or association of ideas; and that they originate in optima 
 forma solely upon the basis of the pathological conditions, which 
 are developed in our bodies, or are inherited from parents. 
 
 If we set out from the theory here advocated this cannot be 
 astonishing; for the vasomotor apparatus can of course upon 
 occasion become diseased as readily as any other portion of the 
 nervous system, so that it functions in an abnormal manner, or 
 cannot function at all. We may even regard it as especially 
 exposed to the danger of functioning in a pathological manner, 
 because it is that part of the nervous system which has least 
 rest and is most frequently liable to functional disturbances.
 
 68o CARL GEORG LANGE 
 
 Where this happens in an individual, he becomes according 
 to circumstances, depressed or distracted, anxious or unre- 
 strainedly merry, embarrassed, etc. Everything is without 
 apparent motive, and even though he is conscious of having no 
 reason whatever for his anger, his fear, or his joy. Where is there 
 any support here for the hypothesis of psychical emotion? 
 
 Such cases are extraordinarily frequent. Every alienist 
 knows the sharply developed forms which appear as melan- 
 cholia or mania; every physician who occupies himself at all 
 thoroughly with nervous diseases has ample opportunity to ob- 
 serve the even more instructive light forms on the borderland 
 between the real diseases of the mind and mere depressions, 
 such as are included under the ordinary names of irritability, 
 oddity, and dejection. Very frequently we find the dejection, 
 the imaginary grief, or even despair, which often results in sui- 
 cide, combined with clear consciousness of the entire absence 
 of a single psychical motive for grief. Not much less frequent is 
 the pathological anxiety, which often accompanies that related 
 emotion of grief, but often enough is found alone. It goes with- 
 out saying, that joy appears more rarely in actual pathological 
 manifestations. The mere circumstance that a joy appears 
 without motive will naturally, at least among the laity, seldom 
 suffice to cause it to be regarded as pathological, and still less to 
 cause medical treatment to be sought for the cure of this state. 
 For such action it will be commonly necessary, that either the 
 joy manifest itself in an entirely unrestrained and immoderate 
 manner in the form of a more or less pronounced mania, or that 
 it alternate in a striking fashion with periods of dejection, and 
 thus attract attention as something unnatural. The same holds 
 true of anger. We are in fact accustomed, as regards this emo- 
 tion, to put up with a good deal without surmising it to be any- 
 thing pathological, and as a rule we are not exacting as to its 
 cause. But everything indeed has its limits, and there are 
 outbreaks of anger often enough so groundless and unre- 
 strained, that all will agree in recognizing them as manifesta- 
 tions of a pathological state. 
 
 There exists probably for those who have no medical training
 
 THE EMOTIONS 681 
 
 scarcely anything that can be more clarifying with reference to 
 the diseased states of the mind here discussed, than the observ- 
 ation of such a pathological paroxysm of temper. Especially 
 is this true, if it appears wholly uncomplicated by other psychi- 
 cal disturbances, as is the case in the form of illness which goes 
 by the name of " transitory mania, " and is indeed of rare occur- 
 rence. The attack comes often without the least apparent cause 
 to an otherwise entirely sane person, if disposed thereto; and 
 throws him to use the language of a recent writer 1 upon this 
 disease into a state of wild paroxysm of rage, accompanied 
 by a terrible and blindly furious impulse to injure and to 
 destroy. The patient suddenly assails everything, strikes, 
 kicks, and strangles whomsoever he can seize, throws every- 
 thing about him that he can lay hands upon, breaks to pieces 
 whatever comes near him, rends his clothes, screams, howls 
 and roars with glaring rolling eyes, and thereby exhibits all 
 the symptoms of vasomotor congestion which we have come to 
 recognize as the accompaniment of madness. The face is 
 flushed and swollen, the cheeks are hot, the eyes are bulging, 
 their conjunctiva are filled with blood, the beating of the heart 
 is increased, and the pulse reaches 100-120 strokes a minute. 
 The neck arteries swell and throb, the veins are distended, the 
 saliva flows. The fit lasts only a few hours, ends suddenly in 
 a sleep of eight to ten hours duration, and upon waking the 
 patient has entirely forgotten what has happened. 
 
 The pathological emotions here mentioned, which originate 
 as stated from abnormal bodily conditions, can appear also as 
 the results of other diseases, or proceed from digestive de- 
 rangements. They are on that account influenced also by the- 
 rapeutic methods, and can be alleviated or cured. The transit- 
 ory mania above described, which has so evidently its cause in 
 a sudden congestion of the brain, can, according to the author 
 cited, be checked oftentimes by a bandage of ice upon the head. 
 
 I foresee here an objection which I shall not pass unnoticed 
 in spite of its logical weakness. Undoubtedly many will say, in 
 harmony with common usage, that the states which are occa- 
 
 1 O. Schwartz, Die transilorische Tobsucht, Wien, 1880.
 
 682 CARL GEORG LANGE 
 
 sioned by purely bodily influences or by diseased bodily condi- 
 tions, can indeed be similar to the emotions, but they are not 
 emotions. For example, the delirium that the fly agaric occa- 
 sions, or that appears in mania, presents indeed the picture of 
 rage, but is not "actual" rage, any more than the happiness 
 which comes from drinking wine is "real" happiness. One 
 cannot for that reason conclude from the absence of moral 
 wrath in the person poisoned by fly agaric or possessed of a 
 mania, that there does not exist at all any such purely psychi- 
 cal state, provided the wrath is brought about in the ordinary 
 way by a moral impression. 
 
 It is easy to see that any such division of emotions into real 
 and apparent, or any such limitation of the domain of real emo- 
 tions is entirely arbitrary, and based upon a petitio principii. 
 The reason of the claim to an exceptional position for the emo- 
 tions of intellectual origin, as if they were the only real ones, is 
 purely and solely the belief, that they are due to the activity of 
 the mind. But that is precisely the question under discussion. 
 
 In reality the difference between the passion of the warrior 
 frenzied by the fly agaric, or of the maniac, and of one who has 
 suffered a mortal offence, exists only in the difference and in the 
 consciousness of the respective causes, or in the absence of the 
 consciousness of any cause. If one desires upon this basis to es- 
 tablish a distinction, there is naturally no objection to be made, 
 provided only one is clear wherein the difference consists. 
 
 Moreover it is not so easy, as it probably appears, to draw a 
 sharp line of distinction between material and psychical causes 
 of emotion; if we seek to analyse their physiological difference, 
 it resolves itself into something physiologically quite irrelevant, 
 and slips from our grasp. 
 
 No one has ever thought of distinguishing a true emotion 
 from one produced by an uncommonly loud noise. No one hesi- 
 tates to regard it as a sort of fright; and in fact it shows all the 
 usual characteristics of fright. And yet it is by no means united 
 with the idea of danger, or in any way occasioned by an associa- 
 tion of ideas, a memory, or any intellectual process whatever. 
 The phenomena of fright follow the noise immediately without
 
 THE EMOTIONS 683 
 
 a trace of "mental" fear. Merely because of the noise of the 
 report, many persons can never become accustomed to stand 
 beside a cannon when it is discharged, although they know per- 
 fectly well there is no danger, either for themselves or for others. 
 The case, moreover, of the infant can be cited, which exhibits 
 all the symptoms of fear whenever it hears a loud noise, and 
 yet we cannot reasonably assume that the sound excited in the 
 child any idea of danger. In this case, we must assume that if 
 the vasomotor reflexes are not directly caused by the acoustic 
 nerves, they are at least by the direct action of the acoustic cen- 
 tres, and we have therefore an emotion of purely material 
 origin. 1 We must therefore either exclude this fear from the 
 true emotions, or we cannot strictly maintain the distinction 
 between the mentally and the bodily conditioned emotions. 
 
 We are placed in the same dilemma by the emotions, as a 
 rule certainly less intensive but nevertheless sufficiently dis- 
 tinct, which are produced by the simple impressions of the 
 other sense organs, and are not united with any kind of associa- 
 tion. Such are, for example, the pleasure from a charming 
 color or combination of colors, the repugnance towards a dis- 
 agreeable taste or odor, or the discomfort from a pain. 
 
 If one has only once begun to feel uncertain about the estab- 
 lishment of a line of demarcation between the mental and bod- 
 ily causes of emotions, there arises a strong impulse to investi- 
 gate what physiological significance can be attributed to their 
 difference. One seeks then what difference exists in the cerebral 
 mechanism of the emotions, according as they are determined 
 by a so-called mental cause, or by one purely material. 
 
 To-day with our still very imperfect knowledge of cerebral 
 physiology, it is certainly not very tempting to make an at- 
 tempt at an explanation of what takes place in the brain as the 
 result of mental work. Naturally, we can only sketch some 
 fundamental outlines very roughly, and, in truth, with every 
 
 1 That we here deal with a simple reflex, immediately produced in the motor 
 nerves, as Preyer appears to suppose (Die Seele des Kindes, 2te Aufl. p. 51) is 
 not probable; partly because these motor phenomena have not in general the 
 character of reflex movement excited by a sudden impression, and partly be- 
 cause the effects in question are not confined to motor phenomena.
 
 684 CARL GEORG LANGE 
 
 possible reserve with reference to the accuracy of the results. 
 Nevertheless, in psychological investigations it is not only just- 
 ifiable, but is also correct and useful to examine how closely we 
 can approach a solution with our present physiological know- 
 ledge. At all events we can take courage from the fact, that we 
 know the relations here discussed in their chief characteris- 
 tics at least are of their kind almost the simplest, and the 
 easiest to fathom.* 
 
 * " The only point," says Th. Ribot in his The Psychology of the Emotions, " in 
 which I differ from these authors [James and Lange] relates to their way of 
 putting the proposition, not to its substance. 
 
 " It is evident that our two authors,whether consciously or not, share the dualist 
 point of view with the common opinion which they are combating; the only differ- 
 ence being in the interversion of cause and effect. Emotion is a cause of which 
 the physical manifestations are the effect, says one party; the physical manifesta- 
 tions are the cause of which emotion is the effect, says the other. In my view, 
 there would be a great advantage in eliminating from the question every notion 
 of cause and effect, every relation of causality, and in substituting for the dual- 
 istic position a unitary or monistic one. The Aristotelian formula of matter and 
 form seems to me to meet the case better, if we understand by 'matter' the 
 corporeal facts, and by 'form 'the corresponding psychical state: the two terms, 
 by-the-bye, only existing in connection with each other and being inseparable ex- 
 cept as abstract conceptions. It was traditional in ancient psychology to study 
 the relations of ' the soul and the body ' the new psychology does not speak of 
 them. In fact, if the question takes a metaphysical form, it is no longer psychol- 
 ogy; if it takes an experimental form, there is no reason to treat it separately, 
 because it is treated in connection with everything. No state of consciousness can 
 be dissociated from its physical conditions: they constitute a natural whole, which 
 must be studied as such. Every kind of emotion ought to be considered in this 
 way: all that is objectively expressed by the movements of the face and body, by 
 vasomotor, respiratory, and secretory disturbances, is expressed subjectively by 
 correlative states of consciousness, classed by external observation according to 
 their qualities. It is a single occurrence expressed in two languages.' We have 
 previously assimilated the emotions to psycho-physiological organisms; this 
 unitary point of view, being more conformable to the nature of things and to the 
 present tendencies of psychology, seems to me, in practice, to eliminate many 
 objections and difficulties. Whether we adopt this theory or not, we have in 
 any case acquired the certainty that the organic and motor manifestations 
 are not accessories, that the study of them is part of the study of emotion." 
 
 Pp. III-II2.
 
 WILHELM WUNDT 
 
 (1832- ) 
 
 PRINCIPLES OF PHYSIOLOGICAL 
 PSYCHOLOGY 
 
 Translated from the German* by 
 EDWARD BRADFORD TITCHENER 
 
 INTRODUCTION 
 i. THE PROBLEM OF PHYSIOLOGICAL PSYCHOLOGY 
 
 THE title of the present work is in itself a sufficiently clear 
 indication of the contents. In it, the attempt is made to show 
 the connexion between two sciences whose subject-matters are 
 closely interrelated, but which have, for the most part, followed 
 wholly divergent paths. Physiology and psychology cover, be- 
 tween them, the field of vital phenomena; they deal with the 
 facts of life at large, and in particular with the facts of human 
 life. Physiology is concerned with all those phenomena of life 
 that present themselves to us in sense perception as bodily 
 processes, and accordingly, form part of that total environment 
 which we name the external world. Psychology, on the other 
 hand, seeks to give account of the interconnexion of processes 
 which are evinced by our own consciousness, or which we infer 
 from such manifestations of the bodily life in other creatures as 
 indicate the presence of a consciousness similar to our own. 
 
 This division of vital processes into physical and psychical 
 is useful and even necessary for the solution of scientific prob- 
 lems. We must, however, remember that the life of an organ- 
 
 * From Gnmdziige der physiologischen Psychologic, 2 Bde. Leipzig, 1873-74; 5 
 umgearb. Aufl. 3 Bde. 1902. Reprinted here from W.Wundt's Principles of Physi- 
 ological Psychology, translated by E. B. Trtchener, New York, The Macmillan 
 Co. 1904.
 
 686 WILHELM WUNDT 
 
 ism is really one; complex, it is true, but still unitary. We can, 
 therefore, no more separate the processes of bodily life from 
 conscious processes than we can mark off an outer experience, 
 mediated by sense perceptions, and oppose it, as something 
 wholly separate and apart, to what we call ' inner ' experience, 
 the events of our own consciousness. On the contrary: just as 
 one and the same thing, e.g., a tree that I perceive before me, 
 falls as external object within the scope of natural science, and 
 as conscious contents within that of psychology, so there are 
 many phenomena of the physical life that are uniformly con- 
 nected with conscious processes, while these in turn are always 
 bound up with processes in the living body. It is a matter of 
 every-day experience that we refer certain bodily movements 
 directly to volitions, which we can observe as such only in our 
 consciousness. Conversely, we refer the ideas of external objects 
 that arise in consciousness either to direct affection of the organs 
 of sense, or, in the case of memory images, to physiological ex- 
 citations within the sensory centres, which we interpret as 
 after-effects of foregone sense impressions. 
 
 It follows then, that physiology and psychology have many 
 points of contact. In general, there can of course be no doubt 
 that their problems are distinct. But psychology is called upon 
 to trace out the relations that obtain between conscious pro- 
 cesses and certain phenomena of the physical life; and physi- 
 ology, on its side, cannot afford to neglect the conscious con- 
 tents in which certain phenomena of this bodily life manifest 
 themselves to us. Indeed, as regards physiology, the interde- 
 pendence of the two sciences is plainly in evidence. Practically 
 everything that the physiologists tell us, by way of fact or of 
 hypothesis, concerning the processes in the organs of sense and 
 in the brain, is based upon determinate mental symptoms: so 
 that psychology has long been recognised, explicitly or im- 
 plicitly, as an indispensable auxiliary of physiological investi- 
 gation. Psychologists, it is true, have been apt to take a dif- 
 ferent attitude towards physiology. They have tended to regard 
 as superfluous any reference to the physical organism; they 
 have supposed that nothing more is required for a science of
 
 PHYSIOLOGICAL PSYCHOLOGY 687 
 
 mind than the direct apprehension of conscious processes 
 themselves. It is in token of dissent from any such standpoint 
 that the present work is entitled a " physiological psychology." 
 We take issue, upon this matter, with every treatment of psy- 
 chology that is based on simple self-observation or on philo- 
 sophical presuppositions. We shall, whenever the occasion seems 
 to demand, employ physiology in the service of psychology. We 
 are thus, as was indicated above, following the example of 
 physiology itself, which has never been in a position to disre- 
 gard facts that properly belong to psychology, although it 
 has often been hampered in its use of them by the defects of 
 the empirical or metaphysical psychology which it has found 
 current. 
 
 Physiological psychology is, therefore, first of all psychology. 
 It has in view the same principal object upon which all other 
 forms of psychological exposition are directed : the investigation 
 of conscious processes in the modes of connexion peculiar to them. 
 It is not a province of physiology; nor does it attempt, as has 
 been mistakenly asserted, to derive or explain the phenomena 
 of the psychical from those of the physical life. We may read 
 this meaning into the phrase ' physiological psychology/ just 
 as we might interpret the title ' microscopical anatomy ' to 
 mean a discussion, with illustrations from anatomy, of what 
 has been accomplished by the microscope; but the words should 
 be no more misleading in the one case than they are in the other. 
 As employed in the present work, the adjective ' physiological ' 
 implies simply that our psychology will avail itself to the full 
 of the means that modern physiology puts at its disposal for 
 the analysis of conscious processes. It will do this in two ways. 
 ( i ) Psychological inquiries have, up to the most recent times, 
 been undertaken solely in the interest of philosophy ; physiology 
 was enabled, by the character of its problems, to advance more 
 quickly towards the application of exact experimental methods. 
 Since, however, the experimental modification of the processes 
 of life, as practised by physiology, oftentimes effects a concomi- 
 tant change, direct or indirect, in the processes of consciousness, 
 - which, as we have seen, form part of vital processes at large,
 
 688 WILHELM WUNDT 
 
 it is clear that physiology is, in the very nature of the case, 
 qualified to assist psychology on the side of method; thus ren- 
 dering the same help to psychology that it itself received from 
 physics. In so far as physiological psychology receives assistance 
 from physiology in the elaboration of experimental methods, 
 it may be termed experimental psychology. This name suggests, 
 what should not be forgotten that psychology, in adopting the 
 experimental methods of physiology, does not by any means 
 take them over as they are, and apply them without change to 
 a new material. The methods of experimental psychology have 
 been transformed in some instances, actually remodelled 
 by psychology itself, to meet the specific requirements of psy- 
 chological investigation. Psychology has adapted physiologi- 
 cal, as physiology adapted psychical methods, to its own ends. 
 (2) An adequate definition of life, taken in the wider sense, 
 must (as we said just now) cover both the vital processes of 
 the physical organism and the processes of consciousness. 
 Hence, wherever we meet with vital phenomena that present 
 the two aspects, physical and psychical, there naturally arises 
 a question as to the relations in which these aspects stand 
 to each other. So we come face to face with a whole series of 
 special problems, which may be occasionally touched upon by 
 physiology or psychology, but which cannot receive their final 
 solution at the hands of either, just by reason of that division 
 of labour to which both sciences alike stand committed. Experi- 
 mental psychology is no better able to cope with them than is 
 any other form of psychology, seeing that it differs from its 
 rivals only in method, and not in aim or purpose. Physiologi- 
 cal psychology, on the other hand, is competent to investigate 
 the relations that hold between the processes of the physical and 
 those of the mental life. And in so far as it accepts this second 
 problem, we may name it a psychophysks. If we free this term 
 from any sort of metaphysical implication as to the relation of 
 mind and body, and understand by it nothing more than an 
 investigation of the relations that may be shown empirically 
 to obtain between the psychical and the physical aspects of 
 vital processes, it is clear at once that psychophysics becomes
 
 PHYSIOLOGICAL PSYCHOLOGY 689 
 
 for us not, what it is sometimes taken to be, a science interme- 
 diate between physiology and psychology, but rather a science 
 that is auxiliary to both. It must, however, render service more 
 especially to psychology, since the relations existing between 
 determinate conditions of the physical organisation, on the 
 one hand, and the processes of consciousness, on the other, 
 are primarily of interest to the psychologist. In its final purpose, 
 therefore, this psychophysical problem that we have assigned 
 to physiological psychology proves to be itself psychological. 
 In execution, it will be predominantly physiological, since psy- 
 chophysics is concerned to follow up the anatomical and physi- 
 ological investigation of the bodily substrates of conscious 
 processes, and to subject its results to critical examination with 
 a view to their bearing upon our psychical life. 
 
 There are thus two problems which are suggested by the 
 title " physiological psychology " : the problem of method, which 
 involves the application of experiment, and the problem of a 
 psychophysical supplement, which involves a knowledge of the 
 bodily substrates of the mental lif e. For psychology itself, the 
 former is the more essential ; the second is of importance mainly 
 for the philosophical question of the unitariness of vital pro- 
 cesses at large. As an experimental science, physiological 
 psychology seeks to accomplish a reform in psychological in- 
 vestigation comparable with the revolution brought about in 
 the natural sciences by the introduction of the experimental 
 method. From one point of view, indeed, the change wrought 
 is still more radical : for while in natural science it is possible, 
 under favorable conditions, to make an accurate observation 
 without recourse to experiment, there is no such possibility 
 in psychology. It is only with grave reservations that what is 
 called ' pure self-observation ' can properly be termed observa- 
 tion at all, and under no circumstances can it lay claim to ac- 
 curacy. On the other hand, it is of the essence of experiment that 
 we can vary the conditions of an occurrence at will and, if we are 
 aiming at exact results, in a quantitatively determinable way. 
 Hence, even in the domain of natural science, the aid of the ex- 
 perimental method becomes indispensable whenever the prob-
 
 690 WILHELM WUNDT 
 
 lem set is the analysis of transient and impermanent phenom- 
 ena, and not merely the observation of persistent and relatively 
 constant objects. But conscious contents are at the opposite 
 pole from permanent objects; they are processes, fleeting occur- 
 rences, in continual flux and change. In their case, therefore, the 
 experimental method is of cardinal importance; it and it alone 
 makes a scientific introspection possible. For all accurate obser- 
 vation implies that the object of observation (in this case the 
 psychical process) can be held fast by the attention, and any 
 changes that it undergoes attentively followed. And this fixa- 
 tion by the attention implies, in its turn, that the observed ob- 
 ject is independent of the observer. Now it is obvious that the 
 required independence does not obtain in any attempt at a direct 
 self -observation, undertaken without the help of experiment. 
 The endeavour to observe oneself must inevitably introduce 
 changes into the course of mental events, changes which 
 could not have occurred without it, and whose usual conse- 
 quence is that the very process which was to have been ob- 
 served disappears from consciousness. The psychological ex- 
 periment proceeds very differently. In the first place, it creates 
 external conditions that look towards the production of a de- 
 terminate mental process at a given moment. In the second 
 place, it makes the observer so far master of the general situa- 
 tion, that the state of consciousness accompanying this process 
 remains approximately unchanged. The great importance of 
 the experimental method, therefore, lies not simply in the fact 
 that, here as in the physical realm, it enables us arbitrarily 
 to vary the conditions of our observations, but also and essen- 
 tially in the further fact that it makes observation itself pos- 
 sible for us. The results of this observation may then be fruit- 
 fully employed in the examination of other mental phenomena, 
 whose nature prevents their own direct experimental modifica- 
 tion. 
 
 We may add that, fortunately for the science, there are other 
 sources of objective psychological knowledge, which become 
 accessible at the very point where the experimental method 
 fails us. These are certain products of the common mental
 
 PHYSIOLOGICAL PSYCHOLOGY 691 
 
 life, in which we may trace the operation of determinate psy- 
 chical motives: chief among them are language, myth and cus- 
 tom. In part determined by historical conditions, they are also, 
 in part, dependent upon universal psychological laws; and the 
 phenomena that are referable to these laws form the subject- 
 matter of a special psychological discipline, ethnic psychology. 
 The results of ethnic psychology constitute, at the same time, 
 our chief source of information regarding the general psychology 
 of the complex mental processes. In this way, experimental 
 psychology and ethnic psychology form the two principal de- 
 partments of scientific psychology at large. They are supple- 
 mented by child and animal psychology, which in conjunction 
 with ethnic psychology attempt to resolve the problems of psy- 
 chogenesis. Workers in both these fields may, of course, avail 
 themselves within certain limits of the advantages of the' ex- 
 perimental method. But the results of experiment are here mat- 
 ters of objective observation only, and the experimental method 
 accordingly loses the peculiar significance which it possesses 
 as an instrument of introspection. Finally, child psychology 
 and experimental psychology in the narrower sense may be 
 bracketed together as individual psychology, while animal 
 psychology and ethnic psychology form the two halves of a 
 generic or comparative psychology. These distinctions within 
 psychology are, however, by no means to be put on a level 
 with the analogous divisions of the province of physiology. 
 Child psychology and animal psychology are of relatively slight 
 importance, as compared with the sciences which deal with the 
 corresponding physiological problems of ontogeny and phylo- 
 geny. On the other hand, ethnic psychology must always 
 come to the assistance of individual psychology, when the de- 
 velopmental forms of the complex mental processes are in 
 question. 
 
 3. PREPSYCHOLOGICAL CONCEPTS 
 
 The human mind is so constituted, that it cannot gather 
 experiences without at the same time supplying an admixture 
 of its own speculation. The first result of this nai've reflection
 
 692 WILHELM WUNDT 
 
 is the system of concepts which language embodies. Hence, 
 in all departments of human experience, there are certain con- 
 cepts that science finds ready made, before it proceeds upon its 
 own proper business, results of that primitive reflection 
 which has left its permanent record in the concept-system of 
 language. 'Heat' and 'light,' e.g., are concepts from the world 
 of external experience, which had their immediate origin in 
 sense perception. Modern physics subsumes them both under 
 the general concept of motion. But it would not be able to do 
 this, if the physicist had not been willing provisionally to ac- 
 cept the concepts of the common consciousness, and to begin 
 his inquiries with their investigation. ' Mind/ ' intellect,' ' rea- 
 son,' ' understanding,' etc., are concepts of just the same kind, 
 concepts that existed before the advent of any scientific psychol- 
 ogy. The fact that the naive consciousness always and every- 
 where points to internal experience as a special source of know- 
 ledge, may, therefore, be accepted for the moment as sufficient 
 testimony to the rights of psychology as science. And this ac- 
 ceptance implies the adoption of the concept of 'mind,' to cover 
 the whole field of internal experience. ' Mind,' will accordingly 
 be the subject, to which we attribute all the separate facts of 
 internal observation as predicates. The subject itself is deter- 
 mined wholly and exclusively by its predicates; and the refer- 
 ence of these to a common substrate must be taken as nothing 
 more than an expression of their reciprocal connexion. In say- 
 ing this, we are declining once and for all to read into the con- 
 cept of ' mind ' a meaning that the naive linguistic consciousness 
 always attaches to it. Mind, in popular thought, is not simply 
 a subject in the logical sense, but a substance, a real being; and 
 the various ' activities of mind,' as they are termed, are its 
 modes of expression or action. But there is here involved a 
 metaphysical presupposition, which psychology may possibly 
 be led to honour at the conclusion of her work, but which she 
 cannot on any account accept, untested, before she has entered 
 upon it. Moreover, it is not true of this assumption as it was of 
 the discrimination of internal experience at large, that it is 
 necessary for the starting of the investigation. The words
 
 PHYSIOLOGICAL PSYCHOLOGY 693 
 
 coined by language to symbolise certain groups of experiences 
 still bear upon them marks which show that, in their primitive 
 meanings, they stood not merely for separate modes of existence, 
 for ' substances,' in general, but actually for personal beings. 
 This personification of substances has left its most indelible 
 trace in the concept of genus. Now the word-symbols of con- 
 ceptual ideas have passed so long from hand to hand in the 
 service of the understanding, that they have gradually lost all 
 such fanciful reference. There are many cases in which we 
 have seen the end, not only of the personification of substances, 
 but even of the substantialising of concepts. But we are not 
 called upon, on that account, to dispense with the use whether 
 of the concepts themselves or of the words that designate them. 
 We speak of virtue, honour, reason; but our thought does not 
 translate any one of these concepts into a substance. They have 
 ceased to be metaphysical substances, and have become logical 
 subjects. In the same way, then, we shall consider mind, for 
 the time being, simply as the logical subject of internal experi- 
 ence. Such a view follows directly from the mode of concept- 
 formation employed by language, except that it is freed of all 
 those accretions of crude metaphysics which invariably attach 
 to concepts in their making by the naive consciousness. 
 
 We must take up a precisely similar attitude to other ready- 
 made concepts that denote special departments or special re- 
 lations of the internal experience. Thus our language makes a 
 distinction between 'mind* and 'spirit.' The two concepts 
 carry the same meaning, but carry it in different contexts: 
 their correlates in the domain of external experience are ' body ' 
 and ' matter.' The name ' matter' is applied to any object of 
 external experience as it presents itself directly to our senses, 
 without reference to an inner existence of its own. ' Body ' is 
 matter thought of with reference to such an inner existence. 
 ' Spirit,' in the same way, denotes the internal existence as 
 considered out of all connexion with an external existence; 
 whereas 'mind,' especially where it is explicitly opposed to 
 spirit, presupposes this connexion with a corporeal existence, 
 given in external experience.
 
 694 WILHELM WUNDT 
 
 While the terms ' mind ' and ' spirit ' cover the whole field of 
 internal experience, the various 'mental faculties,' as they are 
 called, designate the special provinces of mind as distinguished 
 by a direct introspection. Language brings against us an array 
 of concepts like 'sensibility,' 'feeling,' 'reason,' 'understand- 
 ing,' a classification of the processes given in internal per- 
 ception against which, bound down as we are to the use of these 
 words, we are practically powerless. What we can do, however, 
 and what science is obliged to do, is to reach an exact definition 
 of the concepts, and to arrange them upon a systematic plan. 
 It is probable that the mental faculties stood originally not 
 merely for different parts of the field of internal experience, but 
 for as many^different beings; though the relation of these to. the 
 total being, the mind or spirit, was not conceived of in any very 
 definite way. But the hypostatisation of these concepts lies 
 so far back in the remote past, and the mythological interpre- 
 tation of nature is so alien to our modes of thought, that there 
 is no need here to warn the reader against a top great credulity 
 in the matter of metaphysical substances. Nevertheless, there 
 is one legacy which has come down to modern science from the 
 mythopceic age. All the concepts that we mentioned just now 
 have retained a trace of the mythological concept of force; they 
 are not regarded simply as what they really are class- 
 designations of certain departments of the inner experience, but 
 are oftentimes taken to be forces, by whose means the various 
 phenomena are produced. Understanding is looked upon as 
 the force that enables us to perceive truth; memory as the 
 force which stores up ideas for future use; and so on. On the 
 other hand, the effects of these different 'forces ' manifest them- 
 selves so irregularly that they hardly seem to be forces in the 
 proper sense of the word; and so the phrase ' mental faculties' 
 came in to remove all objections. A faculty, as its derivation 
 indicates, is not a force that must operate, necessarily and im- 
 mutably, but only a force that may operate. The influence of 
 the mythological concept of force is here as plain as it could 
 well be; for the prototype of the operation of force as faculty 
 is, obviously, to be found in human action. The original
 
 PHYSIOLOGICAL PSYCHOLOGY 695 
 
 significance of faculty is that of a being which acts. Here, 
 therefore, in the first formation of psychological concepts, we 
 have the germ of that confusion of classification with ex- 
 planation which is one of the besetting sins of empirical psy- 
 chology . The general statement that the mental faculties are 
 class concepts, belonging to descriptive psychology, relieves us 
 of the necessity of discussing them and their significance at the 
 present stage of our inquiry. As a matter of fact, one can quite 
 well conceive of a natural science of the internal experience in 
 which sensibility, memory, reason and understanding should 
 be conspicuous by their absence. For the only things that we 
 are directly cognisant of in internal perception are individual 
 ideas, feelings, impulses, etc.; and the subsumption of these 
 individual facts under certain general concepts contributes ab- 
 solutely nothing toward their explanation. 
 
 At the present day, the uselessness of the faculty-concepts is 
 almost universally conceded. Again, however, there is one 
 point in which they still exercise a widespread influence. Not 
 the general class-concepts, but the individual facts that, in the 
 old order of things, were subsumed under them, are now re- 
 garded in many quarters as independent phenomena, existing 
 in isolation. On this view there is, to be sure, no special faculty 
 of ideation or feeling or volition; but the individual idea, the 
 individual affective process, and the individual voluntary act 
 are looked upon as independent processes, connecting with one 
 another and separating from one another as circumstances 
 determine. Now introspection declares that all these professedly 
 independent processes are through and through interconnected 
 and interdependent. It is evident, therefore, that their separa- 
 tion involves just the same translation of the products of ab- 
 straction into real things as we have charged to the account of 
 the old doctrine of faculties, only that in this case the ab- 
 stractions come a little nearer to the concrete phenomena. An 
 isolated idea, an idea that is separable from the processes of 
 feeling and volition, no more exists than does an isolated 
 mental force of 'understanding.' Necessary as these distinc- 
 tions are, then, we must still never forget that they are based
 
 696 WILHELM WUNDT 
 
 upon abstractions, that they do not carry with them any 
 real separation of objects. Objectively, we can regard the in- 
 dividual mental processes only as inseparable elements of inter- 
 connected wholes. 

 
 OUTLINES OF PSYCHOLOGY 
 
 Translated from the German * by 
 CHARLES HUBBARD JUDD 
 
 //. PSYCHICAL COMPOUNDS 
 
 14. VOLITIONAL PROCESSES 
 
 i. Every emotion, made up, as it is, of a unified series of in- 
 terrelated affective processes, may terminate in one of two 
 ways. It may give place to the ordinary, variable, and relatively 
 unemotional course of feelings. Such effective processes which 
 fade out without any special result, constitute the emotions 
 in the strict sense, such as were discussed in the last paragraph. 
 In a second class of cases the emotional process may pass into 
 a sudden change in ideational and affective content, which 
 brings the emotion to an instantaneous close; such changes in 
 the sensation and affective state which are prepared for by an 
 emotion and bring about its sudden end, are called -volitional 
 acts. The emotion together with its result is a volitional process. 
 
 A volitional process is thus related to an emotion as a pro- 
 cess of a higher stage, in the same way that an emotion is re- 
 lated to a feeling. Volitional act is the name of only one part 
 of the process, that part which distinguishes a volition from an 
 emotion. The way for the development of volitions out of emo- 
 tions is prepared by those emotions in connection with which 
 external pantomimetic expressive movements appear. These 
 expressive movements appear chiefly at the end of the pro- 
 cess and generally hasten its completion; this is especially 
 true of anger, but to some extent also of joy, care, etc. Still, 
 in these mere emotions there is an entire absence of changes 
 
 * From the Grundviss der Psychologic, Lpz. 1896; 7 verb. Aufl. 1905. Re- 
 printed from Wundt's Outlines of Psychology translated by C. H. Judd, Lpz. 
 1897; 3 rev. ed. 1907.
 
 698 WILHELM WUNDT 
 
 in the train of ideas, which changes are the immediate causes of 
 the momentary transformation of the emotion into volitions, and 
 are also accompanied by characteristic feelings. 
 
 This close interconnection of volitional acts with pantomi- 
 metic expressive movements necessarily leads us to consider as 
 the earliest stages of volitional development those volitions 
 which end in certain bodily movements, which are in turn due 
 to the preceding train of ideas and feelings. In other words, we 
 come to look upon volition ending in external volitional acts, 
 as the earliest stages in the development of volitions. The so- 
 called internal volitional acts, on the other hand, or those which 
 close simply with effects on ideas and feelings, appear in every 
 case to be products of later development. 
 
 2. A volitional process which passes into an external act 
 may be defined as an emotion which closes with a pantomi- 
 metic movement and has, in addition to the characteristics 
 belonging to all such movements, the special property of pro- 
 ducing an external effect which removes the emotion itself. Such 
 an effect is not possible for all emotions, but only for those in 
 which the very succession of component feelings produces feel- 
 ings and ideas which are able to remove the preceding emotion. 
 This is, of course, most commonly the case when the final result 
 of the emotion is the direct opposite of the preceding feelings. 
 The fundamental psychological condition for volitional acts 
 is, therefore, the contrast between feelings, and the origin of the 
 first volitions is most probably in all cases to be traced back 
 to unpleasurable feelings which arouse external movements, 
 which in turn produce contrasted pleasurable feelings. The seiz- 
 ing of food to remove hunger, the struggle against enemies 
 to appease the feeling of revenge, and other similar processes 
 are original volitional processes of this kind. The emotions 
 coming from sense-feelings, and the most widespread social 
 emotions such as love, hate, anger, and revenge, are thus, both 
 in men and animals, the common origin of will. A volition is 
 distinguished in such cases from an emotion only by the fact 
 that the former has added to its emotional components an ex- 
 ternal act that gives rise to feelings which, through contrast
 
 OUTLINES OF PSYCHOLOGY 699 
 
 with the feelings contained in the emotion, bring the emotion 
 itself to an end. The execution of the volitional act may then 
 lead directly, as was originally always the case, or indirectly 
 through an emotion of contrasted effective content, into the 
 ordinary quiet flow of feelings. 
 
 3. The richer the ideational and affective contents of experi- 
 ence, the greater the variety of the emotions and the wider the 
 sphere of volitions. There is no feeling or emotion which does 
 not in some way prepare for a volitional act, or at least have 
 some part in such a preparation. All feelings, even those of a 
 relatively indifferent character, contain in some degree an 
 effort towards or away from some end. This effort may be very 
 general and aimed merely at the maintenance or removal of the 
 present affective state. While volition appears as the most com- 
 plex form of affective process, presupposing feelings and emo- 
 tions as its components, still, we must not overlook, on the other 
 hand, the fact that single feelings continually appear which do 
 not unite to form emotions, and emotions appear which do not 
 end in volitional acts. In the total interconnection of psychical 
 processes, however, these three stages are conditions of one 
 another and form the related parts of a single process which is 
 complete only when it becomes a volition. In this sense a feel- 
 ing may be thought of as the beginning of a volition, or a voli- 
 tion may be thought of as a composite affective process, and 
 an emotion may be regarded as an intermediate stage between 
 the two. 
 
 4. The single feelings in an emotion which closes with a 
 volitional act are usually far from being of equal importance. 
 Certain ones among them, together with their related ideas, 
 are prominent as those which are most important in preparing 
 for the act. Those combinations of ideas and feelings which in 
 our subjective consciousness are the immediate antecedents of 
 the act, are called motives of volition. Every motive may be 
 divided into an ideational and an affective component. The first 
 we may call the moving reason, the second the impelling feeling 
 of action. When a beast of prey seizes his victim, the moving 
 reason is the sight of the victim, the impelling feeling may be
 
 7 oo WILHELM WUNDT 
 
 either the unpleasurable feeling of hunger or the race-hate 
 aroused by the sight. The reason for a criminal murder may be 
 theft, removal of an enemy, or some such idea, the impelling 
 feeling the feeling of want, hate, revenge, or envy. 
 
 When the emotions are of composite character, the reasons 
 and impelling feelings are mixed, often to so great an extent 
 that it would be difficult for the author of the act himself to 
 decide which was the leading motive. This is due to the fact 
 that the impelling feelings of a volitional act combine, just 
 as the elements of composite feelings do, to form a unitary 
 whole in which all other impulses are subordinated to a single 
 predominating one; the feelings of like direction strengthening 
 and accelerating the effect, those of opposite direction weaken- 
 ing it. In the combinations of ideas and feelings which we call 
 motives, the final weight of importance in preparing for the act 
 of will belongs to the feelings, that is, to the impelling feel- 
 ings rather than to the ideas. This follows from the very fact 
 that feelings are integral components of the volitional process 
 itself, while the ideas are of influence only indirectly, through 
 their connections with the feelings. The assumption that a 
 volition may arise from pure intellectual considerations, or that 
 a decision may appear which is opposed to the inclinations ex- 
 pressed in the feelings, is a psychological contradiction in itself. 
 It rests upon the abstract concept of a will which is trans- 
 cendental and absolutely distinct from actual psychical voli- 
 tions. The combination of a number of motives, that is, the 
 combination of a number of ideas and feelings which stand out 
 from the composite train of emotions to which they belong as 
 the ideas and feelings which determine the final discharge of 
 the act this combination furnished the essential condition 
 for the development of will, and also for the discrimination of 
 the single forms of volitional action. 
 
 5. The simplest case of volition is that in which a single 
 feeling in an emotion of suitable constitution, together with its 
 accompanying idea, becomes a motive and brings the process 
 to a close through an appropriate external movement. Such 
 volitional processes determined by a single motive, may be
 
 OUTLINES OF PSYCHOLOGY 701 
 
 called simple volitions. The movements in which they terminate 
 are designated impulsive acts. In popular parlance, however, 
 this definition of impulse by the simplicity of the motive, is not 
 sufficiently adhered to. Another element, namely, the char- 
 acter of the feeling that acts as impelling force is, in popular 
 thought, usually brought into the definition. All acts that 
 are determined by sense-feelings, especially common feelings, 
 are generally called impulsive acts without regard to whether a 
 single motive or a plurality of motives is operative. This basis 
 of discrimination is psychologically inappropriate and there is 
 no justification for the complete separation to which it natu- 
 rally leads between impulsive acts and volitional acts as speci- 
 fically distinct kinds of psychical processes. 
 
 By impulsive act, then, we mean a simple volitional act, 
 that is, one resulting from a single motive, without reference 
 to the relative position of this motive in the series of affective 
 and ideational processes. Impulsive action, thus defined, must 
 necessarily be the starting point for the development of all 
 volitional acts, even though it may continue to appear later, 
 along with the complex volitional processes. To be sure, the 
 earliest impulsive acts are those which come from sense-feeling. 
 Thus, most of the acts of animals are impulsive, but such im- 
 pulsive acts appear continually in the case of man, partly as the 
 results of simple sense emotions, partly as the products of the 
 habitual execution of certain volitional acts which were origin- 
 ally determined by complex motives (10). 
 
 6. When several feelings and ideas in the same emotion 
 tend to produce external action, and when those components 
 of an emotional train which have become motives tend at the 
 same time toward different external ends, whether related or 
 antagonistic, then there arises out of the simple act a complex 
 volitional process. In order to distinguish this from a simple 
 volitional act, or impulsive act, we call it a voluntary act. 
 
 Voluntary and impulsive acts have in common the charac- 
 teristic of proceeding from single motives, or from complexes 
 of motives which have fused together and operate as a single 
 unequivocal impulse. They differ in the fact that in voluntary
 
 702 WILHELM WUNDT 
 
 acts the decisive motive has risen to predominance from among 
 a number of simultaneous and antagonistic motives. When a 
 clearly perceptible conflict between these antagonistic motives 
 precedes the act, we call the volition by the particular name 
 selective act, and the process preceding it we call a choice. The 
 predominance of one motive over other simultaneous motives 
 can be understood only when we presuppose such a conflict 
 in every case. But we are conscious of this conflict sometimes 
 clearly, sometimes only vaguely. It is only in those cases in 
 which we are clearly conscious of the conflict that we speak of 
 choice in the narrower sense of the word. The difference be- 
 tween a voluntary activity and a choice activity is therefore 
 a vanishing quantity. We may say, however, that the ordin- 
 ary voluntary process is one in which the psychological con- 
 dition approaches in character impulsive activity, while in 
 choice the difference between impulsive activity and the higher 
 mode of behavior is always clear. We can represent these differ- 
 ent relations, which appear at different stages of voluntary 
 
 development, most ob- 
 viously through some 
 such schematic dia- 
 gram as that in Fig. i. 
 In this diagram the 
 
 FIG. I. Symbolical Representation of (A) an large circles represent 
 Impulsive Act, (B) a Volitional Act, and . , f , f f , 
 
 (C) a Choice. 
 
 field of consciousness, 
 
 while the small circles within the large ones indicate an idea 
 with a feeling tone which serves as the motive. The small 
 circle which lies in the middle represents the decisive motive. 
 Diagram A represents an impulsive activity, B a voluntary 
 activity, and C a choice activity. In C alone the conflict of 
 motives is represented. This is shown in the figure in the 
 arrows which extend between the circles and the central point 
 and represent the conflict of motives. 
 
 7. The psychical process immediately preceding the act, 
 in which process the final motive suddenly gains the ascend- 
 ency, is called in the case of voluntary acts resolution, in the
 
 OUTLINES OF PSYCHOLOGY 703 
 
 case of selective acts decision. The first word indicates merely 
 that action is to be carried out in accordance with some con- 
 sciously adopted motive; the second implies that several 
 courses of action have been presented as possible and that a 
 choice has finally been made. 
 
 In contrast to the first stages of a volition, which can not be 
 clearly distinguished from an ordinary emotional process, the 
 last stages of volition are absolutely characteristic. They are 
 especially marked by accompanying feelings which never ap- 
 pear anywhere but in volitions, and must therefore be regarded 
 as the specific elements peculiar to volition. These feelings are 
 first of all feelings of resolution and feelings of decision. Feelings 
 of decision differ from feelings of resolution only in the fact that 
 the former are more intense. They are both exciting and relax- 
 ing feelings, and may be united under various circumstances with 
 pleasurable or unpleasurable factors. The relatively greater 
 intensity of the feeling of decision is probably due to its contrast 
 with the preceding feeling of doubt which attends the wavering 
 between different motives. The opposition between doubt and 
 decision gives the feeling of relaxation a greater intensity. At 
 the moment when the volitional act begins, the feelings of re- 
 solution give place to the specific feeling of activity, which has 
 its sensation substratum, in the case of external volitional 
 acts, in the sensations of tension accompanying the move- 
 ment. This feeling of activity is clearly exciting in its charac- 
 ter, and may, according to the special motives, of the volition, 
 be accompanied now by pleasurable, now by unpleasurable 
 elements, which may in turn vary in the course of the act and 
 alternate with one another. As a total feeling, this feeling of 
 activity is a rising and falling temporal process extending 
 through the whole act and finally passing into the widely 
 differing feelings, such as those of fulfilment, satisfaction, or 
 disappointment, or into the feelings and emotions connected 
 with the special result of the act. Taking the process as seen 
 in voluntary and selective acts as complete volitional acts, the 
 essential reason for distinguishing impulsive acts from complete 
 volitional acts is to be found in the absence of the antecedent
 
 704 WILHELM WUNDT 
 
 feelings of resolution, and decision. The feeling connected 
 with the motive passes in the case of impulsive acts directly 
 into the feeling of activity, and then into the feelings which 
 correspond to the effect of the act. 
 
 8. The transition from simple to complex volitional acts 
 brings with it a number of other changes which are of great 
 importance for the development of will. The first of these 
 changes is to be found in the fact that the emotions which 
 introduce volitions lose their intensity more and more, as a 
 result of the counteraction of different mutually inhibiting 
 feelings, so that finally a volitional act may result from an 
 apparently unemotional affective state. To be sure, emotion 
 is never entirely wanting; in order that the motive which arises 
 in an ordinary train of feelings may bring about a resolution 
 or decision, it must always be connected with some degree 
 of emotional excitement. The emotional excitement can, how- 
 ever, be so weak and transient that we overlook it. We do this 
 the more easily the more we are inclined to unite in the single 
 idea of the volition both the short emotion which merely attends 
 the rise and action of the motive, and the resolution and execu- 
 tion which constitute the act itself. This weakening of the emo- 
 tions results mainly from the combinations of psychical pro- 
 cesses which we call intellectual development and of which we 
 shall treat more fully in the discussion of the interconnec- 
 tion of psychical compounds ( 17). Intellectual processes can, 
 indeed, never do away with emotions; such processes are, on 
 the contrary, in many cases the sources of new and character- 
 istic emotions. A volition entirely without emotion, determined 
 by a purely intellectual motive, is, as already remarked (p. 
 700), a psychological impossibility. Still, intellectual develop- 
 ment exercises beyond a doubt a moderating influence on emo- 
 tions. This is particularly true whenever intellectual motives 
 enter into the emotions which prepare the way for volitional 
 acts. This may be due partly to the counteraction of the feel- 
 ings which generally takes place, or it may be due partly to the 
 slow development of intellectual motives, for emotions usually 
 are the stronger, the more rapidly their component feelings rise.
 
 OUTLINES OF PSYCHOLOGY 705 
 
 9. Connected with this moderation of the emotional com- 
 ponents of volitions under the influence of intellectual motives, 
 is still another change. It consists in the fact that the act which' 
 closes the volition is not an external movement. The effect 
 which removes the exciting emotion is itself a psychical process 
 which does not show itself directly through any external symp- 
 tom whatever. Such an effect which is imperceptible for ob- 
 jective observation is called an internal volitional act. The 
 transition from external to internal volitional acts is so bound 
 up with intellectual development that the very character of 
 the intellectual processes themselves is to be explained to a 
 great extent by the influence of volitions on the train of ideas 
 ( 15, 9). The act which closes the volition in such a case is 
 some change in the train of ideas, which change follows the pre- 
 ceding motives as the result of some resolution or decision. The 
 feelings which accompany these acts of immediate preparation, 
 and the feeling of activity connected with the change itself, 
 agree entirely with the feelings observed in the case of external 
 volitional acts. Furthermore, action is followed by more or less 
 intense feelings of satisfaction, and a removal of preceding emo- 
 tional and affective strain. The only difference, accordingly, 
 between these special volitions connected with the intellectual 
 development and the earlier forms of volition, is to be found 
 in the fact that here the final effect of the volition does not 
 show itself in an external bodily movement. 
 
 Still, we may have a bodily movement as the secondary 
 result of an internal volitional act, when the resolution refers to 
 an external act to be executed at some later time. In such a case 
 the act itself always results from a second, later volition. The 
 decisive motives for this second process come, to be sure, from 
 the preceding internal volition, but the two are nevertheless 
 distinct and different processes. Thus, for example, the forma- 
 tion of a resolution to execute an act in the future under cer- 
 tain expected conditions, is an internal volition, while the later 
 performance of the act is an external action different from the 
 first, even though requiring the first as a necessary antecedent. 
 It is evident that where an external volitional act arises from
 
 706 WILHELM WUNDT 
 
 a decision after a conflict among the motives, we have a transi- 
 tional form in which it is impossible to distinguish clearly be- 
 tween the two kinds of volition, namely, that which consists 
 in a single unitary process and that which is made up of two 
 processes, that is, of an earlier and a later volition. In such a 
 transitional form, if the decision is at all separated in time 
 from the act itself, the decision may be regarded as an internal 
 volitional act preparatory to the execution. 
 
 10. These two changes which take place during the develop- 
 ment of will, namely, the moderation of emotions and the ren- 
 dering independent of internal volitions, are changes of a pro- 
 gressive order. In contrast with these there is a third process 
 which is one of retrogradation. When complex volitions with the 
 same motive are often repeated, the conflict between the 
 motives grows less intense; the opposing motives which were 
 overcome in earlier cases grow weaker and finally disappear 
 entirely. The complex act has then passed into a simple, or im- 
 pulsive act. This retrogradation of complex volitional processes 
 shows clearly the utter inappropriateness of the limitation of 
 the concept "impulsive" to acts of will arising from sense- 
 feelings. As a result of the gradual elimination of opposing mo- 
 tives, there are intellectual, moral, and aesthetic, as well as 
 simple sensuous, impulsive acts. 
 
 This regressive development is but one step in a process 
 which unites all the external acts of living being, whether they 
 are volitional acts or automatic reflex movements. When the 
 habituating practice of certain acts is carried further, the de- 
 termining motives finally become, even in impulsive acts, 
 weaker and more transient. The external stimulus originally 
 aroused a strongly affective idea which operated as a motive, 
 but now the stimulus causes the discharge of the act before 
 it can arouse an idea. In this way the impulsive movement 
 finally becomes an automatic movement. The more often this 
 automatic movement is repeated, the easier it, in turn, becomes, 
 even when the stimulus is not sensed, as for example in deep 
 sleep or during complete diversion of the attention. The move- 
 ment now appears as a pure physiological reflex, and the voli- 
 tional process has become a simple reflex process.
 
 OUTLINES OF PSYCHOLOGY 707 
 
 This gradual reduction of volitional to mechanical processes, 
 which depends essentially on the elimination of all the psychical 
 elements between the beginning and end of the act, may take 
 place either in the case of movements which were originally 
 impulsive, or in the case of movements which have become 
 impulsive through the retrogradation of voluntary acts. It is 
 not improbable that all the reflex movements of both animals 
 and men originate in this way. As evidence of this we have, 
 besides the above described reduction of volitional acts through 
 practice to pure mechanical processes, also the purposeful 
 character of reflexes, which points to the presence at some time 
 of purposive ideas as motives. Furthermore, the fact that the 
 movements of the lowest animals are all evidently simple vo- 
 litional acts, not reflexes, tells for the same view, so that here 
 too there is no justification for the assumption frequently made 
 that acts of will have been developed from reflex movements. 
 Finally, we can most easily explain from this point of view the 
 fact mentioned in 13, namely, that expressive movements may 
 belong to any one of the forms possible in the scale of external 
 acts. Obviously the simplest movements are impulsive acts, 
 while many complicated pantomimetic movements probably 
 came originally from voluntary acts which passed first into 
 impulsive and then into reflex movements. Observed phenom- 
 ena make it necessary to assume that the retrogradations 
 which begin in the individual life are gradually carried fur- 
 ther through the transmission of acquired dispositions, so 
 that certain acts which were originally voluntary may appear 
 from the first in later descendants as impulsive or reflex move- 
 ments. 
 
 IT. The exact observation of volitional processes is, for 
 the reasons given above, impossible in the case of volitional 
 acts which come naturally in the course of life; the only way 
 in which a thorough psychological investigation can be made, 
 is, therefore, through experimental observation. To be sure, 
 we can not produce volitional processes of every kind whenever 
 we wish to do so, we must limit ourselves therefore to the ob- 
 
 1 Outlines of Psychology, p. 191.
 
 7 o8 WILHELM WUNDT 
 
 servation of such processes as can be easily influenced through 
 external means, namely such as begin with external stimula- 
 tions and terminate in external acts. The experiments which 
 serve this purpose are called reaction experiments. They may 
 be described in their essentials as follows. A volitional process 
 of simple or complex character is incited by an external sense- 
 stimulus and then after the occurrence of certain psychical 
 processes which serve in part as motives, the volition is brought 
 to an end by a motor reaction. Reaction experiments have a 
 second and more general significance in addition to their signi- 
 ficance as means for the analysis of volitional processes. They 
 furnish means for the measurement of the rate of certain psy- 
 chical and psycho-physical processes. 
 
 The simplest reaction experiment that can be tried is as fol- 
 lows. At the end of a short but always uniform interval (2 3 
 sec.) after a signal which serves to concentrate the attention 
 has been given, an external stimulus is allowed to act on some 
 sense-organ. At the moment when the stimulus is perceived, 
 a movement which has been determined upon and prepared 
 before, as, for example, a movement of the hand is executed. 
 The psychological conditions in this experiment correspond es- 
 sentially to those of a simple volition. The sense impression 
 serves as a simple motive, and this is to be followed invariably 
 by a particular act. If now we measure objectively by means 
 of either graphic or other chronometric apparatus, the interval 
 which elapses between the action of the stimulus and the execu- 
 tion of the movement, it will be possible, by frequently repeated 
 experiments of the same kind, to become thoroughly acquainted 
 with the subjective processes which make up the whole 
 reaction, while at the same time the results of the objective 
 measurement will furnish a check for the constancy or possible 
 variations in these subjective processes. This check is especially 
 useful in those cases where some condition in the experiment, 
 and thereby the subjective course of the volition itself, is inten- 
 tionally modified. 
 
 12. Such a modification may, indeed, be introduced even 
 in the simple form of the experiment just described, by vary-
 
 OUTLINES OF PSYCHOLOGY 709 
 
 ing the way in which the reactor prepares, before the appear- 
 ance of the stimulus, for the execution of the act. When the 
 preparation is of such a character that expectation is directed 
 toward the stimulus which is to serve as a motive, and the ex- 
 ternal act does not take place until the stimulus is clearly re- 
 cognized, there results a complete or sensorial form of reaction. 
 When, on the other hand, the preparatory expectation is so 
 directed toward the act, that the movement follows the recep- 
 tion of the stimulus as rapidly as possible, there results a short- 
 ened form of reaction, or the so-called muscular reaction. In 
 the first case the ideational factor of the expectation is a pale 
 memory image of the familiar sense impression. When the 
 period of preparation is more extended, this image oscillates 
 between alternating clearness and obscurity. The effective 
 element is a feeling of expectation which oscillates in a similar 
 manner and is connected with sensations of strain from the 
 sense-organ to be affected, as for example with tension of the 
 tympanic membrane, or of the ocular muscles of accommoda- 
 tion and movement. At the moment when the impression ar- 
 rives the preparatory feelings and sensations mentioned are fol- 
 lowed by a comparatively weak relieving feeling of surprise. 
 This surprise in turn gives place to a clearly subsequent arous- 
 ing feeling of activity which accompanies the reaction move- 
 ment and appears in conjunction with the inner tactual sensa- 
 tions. In the second case, on the other hand, where the reaction 
 is of the shortened form, we may observe during the period of 
 preparatory expectation a pale, wavering memory image of 
 the motor organ which is to react (e. g., the hand) together 
 with strong sensations of strain in the same, and a fairly con- 
 tinuous feeling of expectation connected with these sensations. 
 At the moment when the stimulus arrives the state of expecta- 
 tion gives place to a strong feeling of surprise. There connect 
 with this surprise both the feeling of activity which accom- 
 panies the reaction and also the sensations which arise in the 
 reaction. So rapid is this connection that the surprise and the 
 subsequent state are not distinguished at all, or at most only 
 very vaguely. The sensorial reaction-time is on the average
 
 710 WILHELM WUNDT 
 
 0.210 0.290 sec. ^muscular reaction-time averages from o.ioo 
 0.180 sec. (the shortest time is for sound, the longest for light). 
 13. By introducing special conditions we may make com- 
 plete and shortened reactions the starting points for the study 
 of the development of volitions in two different directions. Com- 
 plete (sensorial) reactions furnish the means of passing from 
 simple to complex volitions because we can in this case easily 
 insert different psychical processes between the perception of 
 the impression and the execution of the reaction. Thus we have 
 a voluntary act of relatively simple character when we allow an 
 act of direct sensory cognition and discrimination to follow the 
 perception of the impression and then let the movement depend 
 on this second process. In this case, not the immediate impres- 
 sion, but the idea which results from the act of cognition or 
 discrimination is the motive for the act to be performed. This 
 motive is only one of a greater or smaller number of equally 
 possible motives which could have come up in place of it; as a 
 result the reaction movement takes on the character of a volun- 
 tary act. In fact, we may observe clearly the feeling of resolu- 
 tion antecedent to the act and also the feelings preceding the 
 feeling of resolution and connected with the perception of the 
 impression. This is still more emphatically the case, and the 
 succession of ideational and affective processes is at the same 
 time more complicated, when we bring in still another psychical 
 process, as for example memory processes, to serve as the motive 
 for the execution of the movement. Finally, the voluntary 
 process becomes one of choice when in such experiments the act 
 is not merely influenced by a plurality of motives in such a way 
 that several must follow one another before one determines the 
 act, but when, in addition to that, one of a number of possible 
 different acts is decided upon according to the motive presented. 
 This kind of reaction takes place when preparations are made 
 for different movements, for example one with the right hand 
 another with the left hand, or one with each of the ten fingers, 
 and the condition is prescribed for each movement that an im- 
 pression of a particular quality shall serve as its motive, for 
 example the impression blue for the right hand, red for the left.
 
 OUTLINES OF PSYCHOLOGY 711 
 
 14. Shortened (muscular) reactions, on the contrary, may 
 be used to investigate the relrogradation of volitional acts as 
 they become reflex movements. In this form of reaction the 
 preparatory expectation is directed entirely toward the ex- 
 ternal act which is to be executed as rapidly as possible, so that 
 voluntary inhibition or execution of the act in accordance with 
 the special character of the impression can here not take place. 
 In other words, a transition from simple to complex acts of will, 
 is in this case impossible. On the other hand, it is easy by prac- 
 tice so to habituate one's self to the invariable connection of 
 an impression and a particular movement, that the process 
 of perception fades out more and more or takes place after the 
 motor impulse, so that finally the movement becomes just like 
 a reflex movement. This reduction of volition to a mechanical 
 process, shows itself objectively most clearly in the shortening 
 of the objective time to that observed for pure reflexes, and 
 shows itself subjectively in the fact that for psychological ob- 
 servation there is a complete coincidence in point of time, of 
 impression and reaction, while the characteristic feeling of re- 
 solution gradually disappears entirely. 
 
 III. INTERCONNECTION OF PSYCHICAL 
 COMPOUNDS 
 
 17. APPERCEPTIVE COMBINATIONS. 
 
 i. Associations in all their forms are regarded by us as 
 passive experiences, because the feeling of activity, which is 
 characteristic of all processes of volition and attention, never 
 arises except as it is added to the already completed association 
 process in a kind of apperception of the resultant, given content. 
 Associations are, accordingly, processes which can arouse 
 volitions but are not themselves directly influenced by voli- 
 tions. This absence of any dependence on volition is, however, 
 the criterion of a passive process. 
 
 The case is essentially different with the second kind of 
 combinations which are formed between different psychical
 
 712 WILHELM WUNDT 
 
 compounds and their elements, namely, the apperceptive com- 
 binations. Here the feeling of activity with its accompanying 
 variable sensations of tension does not merely follow the com- 
 binations as an after-effect produced by them, but it precedes 
 them so that the combinations themselves are immediately re- 
 cognized as formed with the aid of attention. In this sense these 
 experiences are called active experiences. 
 
 2. Apperceptive combinations include a large number of 
 psychical processes which are distinguished in popular parlance 
 under the general terms thinking, reflection, imagination, and 
 understanding. These are all regarded as psychical processes 
 of a type higher than sense perceptions or pure memory pro- 
 cesses, while at the same time they are all looked upon as dif- 
 ferent from one another. Especially is this true of the so-called 
 functions of imagination and understanding. In contrast with 
 this loose view of the faculty theory, association psychology 
 sought to find a unitary principle by subsuming also the apper- 
 ceptive combinations of ideas under the general concept of as- 
 sociation, and at the same time limiting the concept, as noted 
 above, 1 to successive association. This reduction to successive 
 association was effected either by neglecting the essential sub- 
 jective and objective distinguishing marks of apperceptive 
 combinations, or by attempting to avoid the difficulties of an 
 explanation, through the introduction of certain supplementary 
 concepts taken from popular psychology. Thus, "interest" 
 and " intelligence" were credited with an influence on associa- 
 tions. Very often this view was based on the erroneous notion 
 that the recognition of certain distinguishing features in apper- 
 ceptive combinations and associations meant the assertion of 
 a fundamental division between the former and the latter. Of 
 course, this is not true. All psychical processes are connected 
 with associations as much as with the original sense percep- 
 tions. Yet, just as associations always form a part of every 
 sense perception and in spite of that appear in memory pro- 
 cesses as relatively independent processes, so apperceptive 
 combinations are based always on associations, but the essen- 
 1 Outlines of Psychology, p. 251.
 
 OUTLINES OF PSYCHOLOGY 713 
 
 tial attributes of these apperceptive combinations are not 
 traceable to associations. 
 
 3. In trying to account for the essential attributes of apper- 
 ceptive combinations, we may divide the psychical processes 
 which belong to this class into simple and complex apperceptive 
 functions. The simple functions are those of relating and com- 
 paring, the complex those of synthesis and analysis. 
 
 A. Simple Appercepti-ve Functions (Relating and Comparing}. 
 
 4. The most elementary apperceptive function is that of 
 relating two psychical contents to each other. The grounds for such 
 relating are always given in the single psychical compounds 
 and their associations, but the actual carrying out of the pro- 
 cess itself is a special apperceptive activity through which the 
 relation itself becomes a special conscious content, distinct 
 from the contents which are related, though indeed inseparably 
 connected with them. For example, when we recognize the 
 identity of an object with one perceived before, or when we are 
 conscious of a definite relation between a remembered event 
 and a present impression, there is in both cases a relating 
 apperceptive activity connected with the associations. 
 
 So long as the recognition remains a pure association, the pro- 
 cess of relating is limited to the feeling of familiarity which fol- 
 lows the assimilation of the new impression either immediately, 
 or after a short interval. When, on the contrary, apperception 
 is added to association, this feeling is supplied with a clearly 
 recognized ideational substratum. The earlier perception and 
 the new impression are separated in time and then brought 
 into a relation of agreement on the basis of their essential at- 
 tributes. The case is similar when we become conscious of the 
 motives of a memory act. This also presupposes that a compari- 
 son of the memory image with the impression which occasioned 
 it, is added to the merely associative process which gave rise 
 to the image. This, it will be seen, is a process that can be 
 brought about only through attention, 
 
 5. Thus, the relating function is brought into activity through 
 associations, wherever these associations themselves or their
 
 714 WILHELM WUNDT 
 
 products are made the objects of voluntary observation. The 
 relating function is connected, as the examples mentioned 
 show, with the function of comparing, whenever the related 
 contents of consciousness are clearly separated processes, be- 
 longing to one and the same class of psychical experiences. 
 Relating activity is, therefore, the wider concept, comparison 
 is the narrower. A comparison is possible only when the com- 
 pared contents are brought into relation with one another. On 
 the other hand, conscious contents may be related without be- 
 ing compared with one another, as is the case, for example, 
 when an attribute is related to its object, or when one process 
 is related to another which regularly follows or precedes it. As 
 a result of this it follows that where the fuller conditions neces- 
 sary for a comparison are present, the experiences given may be 
 merely related, or they may also be compared with each other. 
 Thus, one calls it relating when he thinks of a present impres- 
 sion as the reason for remembering an earlier experience; he 
 calls it comparing, on the other hand, when he establishes cer- 
 tain definite points of agreement or difference between the 
 earlier and the present impression. 
 
 6. The process of comparing is, in turn, made up of two ele- 
 mentary functions which are as a rule intimately interconnected. 
 These two elementary functions are first, the perception of agree- 
 ments, and second, the perception of differences. There is a mis- 
 taken view prevalent even in present-day psychology. It 
 originated in popular psychology and was strengthened by the 
 discussions of logical intellectualism. It consists in the accept- 
 ance of the notion that the mere existence of psychical ele- 
 ments and compounds is identical with their apperceptive 
 comparison. Every sensation is accordingly treated as a " sens- 
 ory judgment," every immediate perception of distance as 
 a "judgment of depth," and so on through the whole series of 
 processes. In all these cases, however, the judgment appears 
 after the sensations and ideas; the judgment must, therefore, 
 be recognized as a separate process. To be sure, agreements 
 and differences arise in our psychical processes, if they did 
 not we could not observe them. But the comparing activity
 
 OUTLINES OF PSYCHOLOGY 715 
 
 through which these likenesses and differences in sensations and 
 ideas are made evident, is not identical with the sensations and 
 ideas themselves. It is a function which may arise in connection 
 with these elements, but does not necessarily so arise. 
 
 7. Even the psychical elements, that is, sensations, and 
 simple feelings, can be compared with reference to their agree- 
 ments and differences. Indeed, it is through a series of such 
 comparison that we arrange these psychical elements into sys- 
 tems, each one of which contains the elements which are most 
 closely related. Within a given system two kinds of comparison 
 are possible, namely, comparison in respect to quality and 
 comparisons in respect to intensity. Then, too, a comparison 
 between grades of clearness is possible when attention is paid 
 to the way in which the elements appear in consciousness. 
 In the same way comparison is applied to intensive and exten- 
 sive psychical compounds. Every psychical element and every 
 psychical compound, in so far as it is a member of a regular sys- 
 tem, constitutes a psychical magnitude. A determination of the 
 value of such a psychical magnitude is possible only through 
 comparison with some other magnitude in the same system. 
 Psychical magnitude is, accordingly, an original attribute of 
 every psychical element and compound. It is of various kinds, 
 as intensity, quality, extensive (spatial and temporal) value, 
 and when the different states of consciousness are considered, 
 clearness. But the determination of psychical value can be 
 effected only through the apperceptive function of comparison. 
 
 8. Psychical measurement differs from physical measurement 
 in the fact that the latter may be carried out in acts of com- 
 parison separated almost indefinitely in time, because its ob- 
 jects are relatively constant. For example, we can determine 
 the height of a certain mountain to-day with a barometer and 
 then after a long time we may determine the height of another 
 mountain, and if no sensible changes in the configuration of the 
 land have taken place in the interval, we can compare the re- 
 sults of our two measurements. Psychical compounds, on the 
 other hand, are not relatively permanent objects, but contin- 
 ually changing processes, so that we can compare two such
 
 7i 6 WILHELM WUNDT 
 
 psychical magnitudes only when other conditions remain the 
 same, and when the two factors to be compared follow each 
 other in immediate succession. These requirements have as 
 their immediate corollaries: first, that there is no absolute 
 standard for the comparison of psychical magnitudes, but 
 every such comparison stands by itself and is of merely relative 
 validity; second, that finer comparisons are possible only be- 
 tween psychical magnitudes of the same dimension, so that a 
 reduction, analogous to that by which the most widely separated 
 physical quantities, such as periods of time and physical forces, 
 are all expressed in terms of one dimension of space, is out of the 
 question in psychical comparisons. 
 
 9. It follows that the possible relations between psychical 
 magnitudes which can be established by direct comparison 
 are limited in number. The establishment of such relations 
 is possible only in certain particularly favorable cases. These 
 favorable cases are (i) the equality between two psychical mag- 
 nitudes and (2) the just noticeable difference between two suck 
 magnitudes, as for example two sensation intensities of like 
 quality, or two qualities of like intensity belonging to the same 
 dimension. As a somewhat more complex case which still lies 
 within the limits of immediate comparison we have (3) the 
 equality of two differences between magnitudes, especially when 
 these magnitudes belong to neighboring parts of the same sys- 
 tem. It is clear that in each of these three kinds of psychical 
 measurements the two fundamental functions in apperceptive 
 comparison, namely the perception of agreements and the per- 
 ception of differences, are both applied together. In the first 
 case, one of two psychical magnitudes, A and B, is gradually 
 varied until it agrees for immediate comparison with the other; 
 thus, for example, B is varied until it agrees with A. In the 
 second case A and B are taken equal at first and then B is 
 changed until it appears either just noticeably greater or just 
 noticeably smaller than A . Finally, the third case is used to the 
 greatest advantage when a whole line of psychical magnitudes, 
 as for example of sensation intensities, extending from A as a 
 lower limit to C as an upper limit, is so divided by a middle
 
 OUTLINES OF PSYCHOLOGY 717 
 
 quantity B, which has been found by gradual variations, and 
 is so placed that the partial distance 4.B is apperceived as equal 
 toBC. 
 
 10. The most direct and most easily utilizable results de- 
 rived from these methods of comparison are given by the second 
 method, or the method of minimal differences as it is called. The 
 difference between the physical stimuli which corresponds to 
 the just noticeable difference between psychical magnitudes is 
 called the difference threshold of the stimulus. The intensity 
 at which the resulting psychical process, as for example a 
 sensation, can be just apperceived, is called the stimulus 
 threshold. Observation shows that the difference threshold of 
 the stimulus increases in proportion to the distance from the 
 stimulus threshold, in such a way that the relation between the 
 difference threshold and the absolute quantity of the stimulus 
 or the relative difference threshold, remains constant. If, for 
 example, a certain sound the intensity of which is i must be 
 increased 1-3 in order that the sensation may be just noticeably 
 greater, a sound whose intensity is 2 must be increased 2-3, one 
 with an intensity 3 must be increased 3-3, etc., to reach the dif- 
 ference threshold. This law is called Weber's law, after its 
 discoverer E. H. WEBER. It is easily understood when we look 
 upon it as a law of apperceptive comparison. From this point of 
 view it must obviously be interpreted to mean that psychical 
 magnitudes can be compared only according to their relative values. 
 
 This view that WEBER'S law is an expression of the general 
 law of the relativity of psychical magnitudes, assumes that the 
 psychical magnitudes which are compared, themselves in- 
 crease within the limits of the validity of the law in direct pro- 
 portion to their stimuli. It has not yet been possible to demon- 
 strate the truth of this assumption on its physiological side, on 
 account of the difficulties of measuring exactly the stimulation 
 of nerves and sense-organs. Still, we have evidence in favor of 
 it in the psychological fact that in certain special cases, where 
 the conditions of observation lead very naturally to a compari- 
 son of absolute differences in magnitude, the absolute difference 
 threshold, instead of the relative threshold, is found to be con-
 
 7i 8 WILHELM WUNDT 
 
 stant. We have such a case, for example, in the comparison, 
 within wide limits, of minimal differences hi pitch. Then, too, 
 where large differences hi sensations are compared according 
 to the third method described above (p. 716), it is found in 
 general that equal absolute stimulus differences, not relative 
 differences, are perceived as equal. This shows that appercep- 
 tive comparison follows two different principles under different 
 conditions, a principle of relative comparison (WEBER'S law) 
 which is the more general, and a principle of absolute compari- 
 son which takes the place of the first principle under special 
 conditions which favor such a form of apperception. 
 
 ii. As special cases among the apperceptive comparisons 
 generally falling under WEBER'S law, are the comparisons of 
 magnitudes which are related to each other as relatively greatest 
 sensation differences or, when dealing with feelings, as opposites. 
 The phenomena which appear in such cases are usually grouped 
 together under the class name contrasts. In the department 
 where contrasts have been most thoroughly investigated, that 
 is, in the case of light sensations, there is generally an utter lack 
 of discrimination between two phenomena which are obviously 
 entirely different in origin, though their results are to a certain 
 extent related. We may distinguish these as light induction or 
 physiological contrast, and true contrast or psychological con- 
 trast. Physiological contrasts are closely connected with the 
 phenomena of after-images, perhaps they are the same. Psycho- 
 logical contrasts are essentially different; they are usually 
 pushed into the background by the stronger physiological 
 contrasts when the im pressions are intense. Psychological con- 
 trasts are distinguished from physiological by two important 
 characteristics. First, psychical contrasts do not reach their 
 greatest intensity when the brightness and saturation are 
 greatest, but when the sensations are at the medium stages, 
 where the eye is most sensitive to changes in brightness and 
 saturation. Second, under favorable conditions psychical con- 
 trasts can be removed by comparison with an independent 
 object. Especially the latter characteristic shows these con- 
 trasts to be unqualifiedly the products of comparisons. Thus
 
 OUTLINES OF PSYCHOLOGY 719 
 
 for example, when a gray square, is laid on a black ground and 
 close by a similar gray square is laid on a white ground and 
 all are covered with transparent paper, the two squares appear 
 entirely different ; the one on the black ground looks bright, 
 nearly white, while the square on the white ground looks dark, 
 nearly black. Now after-images and irradiations are very weak 
 when the colors are thus seen through translucent media, so 
 that it may be assumed that the phenomenon described is a 
 psychical contrast. If, again, a strip of black cardboard which 
 is also covered with the transparent paper, and is therefore 
 exactly the same gray as the two squares, is held in such a 
 position that it connects the two squares, the contrast will be 
 entirely removed, or, at least, very much diminished. If in this 
 experiment a colored ground is used instead of the achromatic 
 ground, the gray squares will appear very clearly in the corre- 
 sponding complementary color. But here, too, the contrast 
 can be made to disappear through comparison with an inde- 
 pendent gray object. 
 
 12. Similar contrasts appear also in other spheres of sensa- 
 tion when the conditions for their demonstration are favor- 
 able. They are also especially marked in the case of feelings 
 and may arise under proper conditions in the case of spatial 
 and temporal ideas. Sensations of pitch are relatively most free 
 from contrast, for most persons have a well developed ability 
 to recognize absolute pitch and this probably tends to overcome 
 contrast. In the case of feelings the effect of contrast is intimately 
 connected with the natural opposition between effective quali- 
 ties. Thus, pleasurable feelings are intensified by unpleasant 
 feelings immediately preceding, and the same holds for many 
 feelings of relaxation following feelings of strain, as for example 
 in the case of a feeling of fulfilment after expectation. The effect 
 of contrast in the case of spatial and temporal ideas is most 
 obvious when the same spatial or temporal interval is compared 
 alternately with a longer and with a shorter interval. In such 
 cases the interval appears different; in comparison with the 
 shorter it appears greater, in comparison with the longer, 
 smaller. Here, too, the contrast between spatial ideas can be
 
 720 WILHELM WUNDT 
 
 removed by bringing an object between the contrasted figures 
 in such a way that it is possible easily to relate them. 
 
 13. We may regard the phenomena which result from the 
 apperception of an impression the real character of which dif- 
 fers from the character expected, as special modifications of 
 psychical contrast. For example, if we are prepared to lift a 
 heavy weight, and find in the actual lifting of the weight that 
 it proves to be light, or if we lift a heavy weight when we ex- 
 pected a light one, the result is in the first case an underestima- 
 tion, in the second an overestimation of the real weight. If a 
 series of exactly equal weights of different sizes are made to 
 vary in size so that they look like a set of weights varying 
 regularly from a lighter to a heavier they will appear to be dif- 
 ferent in weight when raised. The smallest will seem to be the 
 heaviest and the largest to be the lightest. The familiar as- 
 sociation that the greater volume is connected with the greater 
 mass determines in this case the tendency of expectation. The 
 false estimation of the weight then results from the contrast 
 between the real and the expected sensation. 
 
 B. Complex Apperceptive Functions. (Synthesis and Analysis). 
 
 14. When the simple processes of relating and comparing 
 are repeated and combined several times, the complex psychical 
 functions of synthesis and analysis arise. Synthesis is primarily 
 the product of the relating activity of apperception, analysis 
 of the comparing activity. 
 
 As a combining function ap perceptive synthesis is based 
 upon fusions and associations. It differs from fusions and as- 
 sociations in the fact that some of the ideational and affective 
 elements which are brought forward by the association are 
 voluntarily emphasized and others are pushed into the back- 
 ground. The motives for the choice between the elements can 
 be explained only from the whole previous development of the 
 individual consciousness. As a result of this voluntary activity 
 the product of this synthesis is a complex in which all the com- 
 ponents are derived from former sense perceptions and associa- 
 tions, but in which the combination of these components may 
 differ more or less from the original forms.
 
 OUTLINES OF PSYCHOLOGY 721 
 
 The ideational elements of a compound thus resulting from 
 apperceptive synthesis may be regarded as the substratum 
 for the rest of its contents, and so we call such a compound in 
 general an aggregate idea. When the combination of the elements 
 is peculiar, that is, markedly different from the products of 
 associations, the aggregate idea and each of its relatively in- 
 dependent ideational components is called an idea of imagina- 
 tion or image of imagination. Since the voluntary synthesis may 
 vary more or less from the combinations presented in sense 
 perception and association, it follows that practically no sharp 
 line of demarcation can be drawn between images of imagina- 
 tion and those of memory. But we have a more essential mark 
 of the apperceptive process in the positive characteristic which 
 appears in the fact that it depends on a voluntary synthesis, 
 than we have in the negative fact that the combination does 
 not correspond in character to any particular sense perception. 
 This positive characteristic is also the source of a most striking 
 difference between images of imagination and those of memory. 
 The difference in question consists in the fact that the sensation 
 elements of an apperceptive compound are much more like 
 those of an immediate sense perception in clearness and dis- 
 tinctness, and usually also in completeness and intensity. This 
 is easily explained by the fact that the reciprocally inhibitory 
 influences which the uncontrolled associations exercise on one 
 another, and which prevent the formation of fixed memory 
 images, are diminished or removed by the voluntary empha- 
 sizing of certain particular ideational compounds. It is possible 
 to mistake images of imagination for real experiences. In the 
 case of memory images this is possible only when they become 
 images of imagination, that is, when the memories are no longer 
 allowed to arise passively, but are to some extent produced by 
 the will. Generally, there are such voluntary modifications of 
 memories through a mixing of real with imagined elements. 
 All our memories are therefore made up of "fancy and truth. " 1 
 Memory images thus change under the influence of our feelings 
 and volition to images of imagination, and we generally deceive 
 ourselves with their resemblance to real experiences. 
 
 1 Dichlung und Wahrheit.
 
 722 WILHELM WUNDT 
 
 15. From the aggregate ideas which thus result from apper- 
 ceptive synthesis there arise two forms of apperceptive analysis 
 which work themselves out in opposite directions. The one is 
 known in popular parlance as activity of the imagination, the 
 second as activity of the understanding. The two are by no 
 means absolutely different, as might be surmised from these 
 names, but are, rather, closely related and always connected 
 with each other. Their fundamental determining motives are 
 what distinguish them and condition all their secondary dif- 
 ferences and also the reaction which they exercise on the syn- 
 thetic function. 
 
 In the case of the activity of "imagination" the motive is 
 the reproduction of real complexes of experience or of experi- 
 ences analogous to reality. This is the earlier form of apperceptive 
 analysis and arises directly from association. It begins with a 
 more or less comprehensive aggregate idea made up of a variety 
 of ideational and affective elements and embracing the general 
 content of a complex experience in which the single compo- 
 nents are only indefinitely distinguished. The aggregate idea 
 is then divided in a series of successive acts into a number of 
 more definite, connected compounds, partly spatial, partly 
 temporal in character. The primary voluntary synthesis is 
 thus followed by analytic acts which may in turn give rise to 
 the motives for a new synthesis and thus to a repetition of 
 the whole process with a partially modified, or more limited 
 aggregate idea. 
 
 The activity of imagination shows two stages of development. 
 The first is more passive and arises directly from the ordinary 
 memory function. It appears continually in the train of thought 
 especially in the form of an anticipation of the future, and plays 
 an important part in psychical development as a preparation 
 or antecedent of volitions. It may, however, in an analogous 
 way, appear as a representation in thought of imaginary situa- 
 tions or of successions of external phenomena. The second, or 
 active, form of imagination is under the influence of a fixed 
 idea of some end, and therefore presupposes a high degree of 
 voluntary control over the images of imagination, and a strong
 
 OUTLINES OF PSYCHOLOGY 723 
 
 interference, partly inhibitory, partly selective, with the mem- 
 ory images that tend to push themselves into consciousness 
 without voluntary action. Even the first synthesis of the ag- 
 gregate idea is more systematic when produced by this active 
 process. And an aggregate idea, when once formed in this way, 
 is held more firmly and subjected to a more complete analysis 
 than in passive imagination. Very often the components them- 
 selves are subordinate aggregate ideas to which the same pro- 
 cess of analysis is again applied. In this way the principle of 
 organic division according to the end in view governs all the 
 products and processes of active imagination. The produc- 
 tions of art show this most clearly. Still, there are, in the ordi- 
 nary play of imagination, the most various intermediate stages 
 between passive imagination, or that which arises directly 
 from memory, arid active imagination, or that which is directed 
 by fixed ends. 
 
 1 6. In contrast with this imagination or imaginative re- 
 production of real experiences, or of experiences which may 
 be thought of as real, the function of the "understanding" is 
 the perception of agreements and differences and other derived 
 logical relations between contents of experience. Understanding 
 also begins with aggregate ideas in which a number of experi- 
 ences which are real or may be ideated as real, are voluntarily 
 set in relation to one another and combined into a unitary whole. 
 The analysis which takes place in this case, however, is turned 
 by its fundamental motive in a different direction. Such analy- 
 sis consists not merely in a clearer grasp of the single compo- 
 nents of the aggregate idea, but it consists also in the establish- 
 ment of the manifold relations which exist between the various 
 components and which we may discover through comparison. 
 In establishing such relations itis possible, as soon as analyses 
 have been made several times, to introduce into any particular 
 case the results gained through relating and comparing processes 
 which were carried out on other occasions. 
 
 As a consequence of this stricter application of the element- 
 ary relating, and comparing functions, the activity of under- 
 standing follows definite rules even in its external form, especi-
 
 7 2 4 WILHELM WUNDT 
 
 ally when it is highly developed. The fact which showed itself 
 in the case of imagination and even of memory, appears here in 
 a developed form. The fact in question is that the apperceived 
 relations between the various psychical contents are presented 
 in imagination and memory, not merely simultaneously, but 
 successively, so that we proceed fiom one relation to the next, 
 and so on. In the case of understanding, this successive present- 
 ation of relations develops into the discursive division of the 
 aggregate idea. This is expressed in the law of the duality of the 
 logical forms of thought, according to which, analysis resulting 
 from relating comparison divides the content of the aggre- 
 gate idea into two parts, subject and predicate, and may then 
 separate each of these parts again once or several times. These 
 secondary divisions give rise to grammatical forms which stand 
 in a logical relation analogous to that of subject and predicate, 
 such as noun and attributive, verb and object, verb and ad- 
 verb. In this way the process of apperceptive analysis results 
 in a judgment which finds expression in the sentence. 
 
 For the psychological explanation of judgment it is of funda- 
 mental importance that judgment be regarded, not as a syn- 
 thetic, but as an analytic function. The original aggregate ideas 
 which are divided by judgment into their reciprocally related 
 components, are exactly like ideas of imagination. The pro- 
 ducts of analysis which result from judgment are, on the other 
 hand, not as in the case of imagination, images of more limited 
 extent and greater clearness, but conceptual ideas, that is, ideas 
 which stand, with regard to other partial ideas of the same 
 w.hole, in some one of the relations which are discovered through 
 the general relating and comparing functions. If we call the 
 aggregate idea which is subjected to such a relating analysis 
 a thought, then a. judgment is a division of this thought into its 
 components, and a concept is the product of such a division. 
 
 17. Concepts found in this way are arranged in certain 
 general classes according to the character of the analyses 
 which produced them. These classes are the concepts of objects, 
 concepts of attributes, and concepts of states. Judgment as a 
 division of the. aggregate idea, sets an object in relation to its
 
 OUTLINES OF PSYCHOLOGY 725 
 
 attributes or states, or it sets various objects in relation to one 
 another. Since a single concept can never, strictly speaking, 
 be thought of by itself, but is always connected in the whole 
 idea with one or more other concepts, the conceptual ideas 
 are strikingly different from the ideas of imagination because 
 of the indenniteness and variableness of the former. This 
 indefiniteness is essentially increased by the fact that as 
 a result of the like outcome of different kinds of judgment, 
 concepts arise which may form components of many ideas 
 which differ in their concrete characters. A concept of this 
 kind can therefore be used in a great variety of different ap- 
 plications. Such general concepts constitute, on account of 
 the wide application of relating analysis to different contents 
 of judgment, the great majority of all concepts; and they 
 have a greater or smaller number of corresponding single 
 ideational contents. A single idea is selected from this group 
 of contents as a representative of the concept. This gives 
 the conceptual idea of a greater definiteness. At the same 
 time there is always connected with this idea the conscious- 
 ness that it is merely a representative. This consciousness 
 generally takes the form of a characteristic feeling, the conceptual 
 feeling. This feeling may be traced to the fact that obscure 
 ideas, which have the attributes which make them suitable 
 to serve as representations of the concept, tend to force them- 
 selves into consciousness in the form of memory images. As 
 evidence of this we have the fact that the feeling is very in- 
 tense when any concrete image of the concept is chosen as 
 its representative, as for example when a particular individual 
 stands for the concept man, while it disappears almost en- 
 tirely as soon as the representative idea differs entirely in 
 content from the objects included under the concept. Word 
 ideas fulfill this latter condition and that is what gives them 
 their importance as universal aids to thought. Word ideas 
 are furnished to the individual consciousness in a finished 
 state, so that we must leave to social psychology the ques- 
 tion of the psychological development of the processes of 
 thought which are active in their formation.
 
 726 WILHELM WUNDT 
 
 18. From all that has been said it appears that the activ- 
 ities of imagination and understanding are not specifically 
 different, but interrelated; that they are inseparable in their 
 rise and manifestations, and are based at bottom on the same 
 fundamental functions of apperceptive synthesis and analysis. 
 What was true of the concept " memory " l holds also of the con- 
 cepts "understanding" and "imagination"; they are names, 
 not of unitary forces or faculties, but of complex phenomena 
 made up of the usual elementary psychical processes; they are 
 not made up of elementary processes of a specific, distinct kind. 
 Just as memory is a general concept for certain associative pro- 
 cesses, so imagination and understanding are general concepts 
 for particular forms of apperceptive activity. They have a 
 certain practical value as ready means for the classification of 
 a variety of differences in the capacity of various persons for 
 intellectual activity. Each class thus found may in turn con- 
 tain an endless variety of gradations and shades. Thus, neg- 
 lecting the general differences in grade, we have as the chief 
 forms of individual imagination the perceptive and combining 
 forms; as the chief forms of understanding, the inductive and 
 deductive forms, the first being mainly concerned with the single 
 logical relations and their combinations, the second more 
 with general concepts and their analysis. A person's talent is 
 his total capacity resulting from the special tendencies of both 
 his imagination and understanding. 
 
 1 Outlines of Psychology, p. 277.
 
 INDEX
 
 INDEX 
 
 Abstraction, 486. 
 
 Affections, 93-96. 
 
 Agreement, 485, 490-496. 
 
 Alban, St., 160. 
 
 Albertus Magnus, 210. 
 
 Alcmaeon, 9. 
 
 Analysis, 720-726. 
 
 Anaxagoras, i, 6, 7, 8, 70, 72, 121, 122. 
 
 Andrew, St., 157. 
 
 Anger, 4, 34, 167. 
 
 Animals, 13, 25, 67, 70, 79, 139-142, 
 221-224, 364, 372, 694. 
 
 Antipater, 86. 
 
 Apperception, 222, 711-726. 
 Appetite, 51, 81, 164-167, 182, 518. 
 Apollodorus, 86. 
 Archer, William, 665. 
 
 Aristotle, i-io, 45-83, 117, 121, 122, 
 
 139, 140, 141, 189, 209, 213. 
 Assimilation, 590-594. 
 Association, 156-160, 202-204, 3*3" 
 
 330, 463-504, 7"-726. 
 Atoms, 8, 96, 213-214. 
 Attention, 317, 336-337, 345, 354, 360. 
 Attribute, 4, 5, 95, 193-195, 203. 
 Augustine, Saint, 120, 132-137. 
 Avenarius, 610. 
 Axioms, 192, 365, 366. 
 
 Bacon, John, 210. 
 
 Bain, Alexander, 463, 483-504. 
 
 Baly, William, 530-544. 
 
 Beauty, 25, 37, 129, 130, 443, 446-447- 
 
 Belief, 160-163, 362-367, 373. 
 
 Beneke, FriedrichEduard, 416-431, 621. 
 
 Berkeley, George, 256-278, 646. 
 
 Bichat, 456. 
 
 Blindness, 262-263, 272-277, 283, 331, 
 S3 2 , S56. 
 
 Blood, 171, 185, 537, 594- 
 
 Body, 4, 23, 45-50, 91-112, 118, 135, 
 143-146, 169-184, 197-222, 332-335, 
 413-415, 426-436, 565, 599-6o8, 693. 
 
 Brown, Thomas, 374-394. 
 Bythus, 121. 
 
 Cajsar, Julius, 366. 
 
 Causality, 198, 204, 289-294, 302-312, 
 
 480-1. 
 
 Cause, final, 52-56, 221, 225. 
 Cerebellum, 316. 
 Child, 445, 471. 
 Chrysippus, 84, 86, 118. 
 Cicero, 117. 
 Cleanthes, 117, 118. 
 Cleon, 62, 74. 
 
 Cognition, i, 11-26, 37, 75-77, 710. 
 Color, 24, 61, 141, 146, 245, 283, 292, 
 
 474, 522, 532, 582, 600, 601, 612, 630. 
 Color-vision, 16, 149, 247, 264, 331, 
 
 476-477, 573-58i, 596. 
 Commodus, 165. 
 Common-sense, 62-66. 
 Common sensibles, 60-62. 
 Concepts, 395~4i3, 435~437, 691-696, 
 
 724-725. 
 
 Conception, 148-149, 155, 161, 165. 
 Condillac, fitienne Bonnot de, 341-360. 
 Connection, necessary, 253-255, 257, 
 
 271-273, 301, 302-312. 
 Consciousness, 361, 398, 401-403, 424, 
 
 506-526, 565-572, 591, 633-655,685- 
 
 690. 
 Cordemoi, 213. 
 Contiguity, 301, 3 11-3", 480, 485, 
 
 499-503. 
 Critias, 9, 117. 
 Critolaus, 117. 
 
 romwell, Oliver, 366. 
 Cyclops, 85. 
 
 Darwin, 538, 669, 670. 
 Davies, J. L., 27-44. 
 Democritus, i, 6, 7, 8, 122, 211, 213. 
 Descartes, Ren, 168-190, 213, 214, 
 656.
 
 730 
 
 INDEX 
 
 De Sens, 175. 
 
 Desire, 51, 78-80, 356-358, 442,457- 
 
 Development, psychical, 416-423. 
 
 Dieterici, C., 570. 
 
 Diogenes, 8, 622. 
 
 Diogenes Laertius, 84-96. 
 
 Disease, 18, 88, 127, 131, 155. 
 
 Dissimilation, 590-594. 
 
 Distance, perception of, 256-278, 362, 
 
 363, 616. 
 
 Don Quixote, 366. 
 
 Dreams, 18, 19, 93, 215, 321, 328, 469. 
 Dressier, J. G., 416. 
 Drobisch, Moritz Wilhelm, 432-447. 
 Du Bois-Reymond, 585. 
 Duncan, George Martin, 208-228. 
 Dyde, Samuel Walters, 11-26. 
 Dynamics, 218, 432-447. 
 
 Ear, 126, 265, 267, 338. 
 
 Effort, 448-462. 
 
 Elements, 20, 21, 24, 597-618. 
 
 Elliott, 538. 
 
 Embryo, 142. 
 
 Emotion, 87, 88, 121, 125, 127, 163- 
 
 190, 285, 389, 486, 490, 496, 508, 655- 
 
 684,697-705. 
 
 Empedocles, I, 7, 12, 54, 65, 73, 117. 
 Endowment, 125-131. 
 Energy, 114, 115, 303, 538, 565. 
 Entelechies, 210. 
 Epicurus, 89-96, 117. 
 Error, 93, 186, 187, 211. 
 Ethics, 191-207. 
 Eubulus, 117. 
 Euripides, 15. 
 Evolution, 505-629. 
 Experience, 158-159, 249, 268, 270, 276, 
 
 435, 610, 653, 676, 686, 693, 723. 
 Extension, 193-203, 256-278, 380-389, 
 
 474-476. 
 Eye, 105, 126, 257-278, 533, 534, SSO- 
 
 554- 
 
 Faculties, 24, 27-41, 45-83* 109, 124, 
 
 148, 331-340, 445-447- 
 Faculty-psychology, 229-231. 
 Fatigue, 336, 378, 591. 
 Fear, 166, 167, 356-358, 382, 656-668, 
 
 682-683. 
 
 Fechner, Gustav Theodor, 562-572, 
 
 586, 587, 588, 596. 
 Feeling, 139, 221, 442-445, 483, 505- 
 
 529, 635, 655-684, 695, 697-705, 725. 
 Feeling, common, 557-561. 
 Feeling, muscular, 374-380, 553-556. 
 Fibres, 334~34O, 575-581. 
 Findlater, Andrew, 463. 
 Force, 144, 209, 210, 231, 395-408, 694. 
 Form, 50, 138-142. 
 Formula, measurement, 565-572. 
 Franklin, 504. 
 
 Free-will, 177, 186, 188, 215. 
 Fusion, tonal, 619-632. 
 
 Gal ton, Mr., 646. 
 
 Gay, Rev. William, 313. 
 
 Genius, 503, 504, 653. 
 
 Geometry, 2, 295. 
 
 Gland, pineal, 173-180. 
 
 Glaucon, 27-44. 
 
 Gloucester, Duke of, 160. 
 
 Goethe, 538, 597, 638. 
 
 Goldsmith, 378. 
 
 Good and evil, 81, 130, 146, 186, 225. 
 
 Greeks, 97, 120. 
 
 Gregory of Nyssa, 125-131. 
 
 Green, T. H., 279. 
 
 Grose, T. H., 279. 
 
 Grote, George, 463. 
 
 Habit, 324, 339, 354, 486, 601. 
 
 Haddon, Arthur West, 132-137. 
 
 Hagenauer, Rev. Mr., 667. 
 
 Haller, 456. 
 
 Hamilton, Sir William, 486. 
 
 Hammond, William Alexander, 45-83. 
 
 Hand, 425, 517, 710. 
 
 Harmony, 64, 217-228, 372, 648. 
 
 Hartley, David, 313-33. 482. 
 
 Hartsoeker, 211. 
 
 Harvey, 171. 
 
 Hearing, 63, 149, 538-542, S57-56i, 
 
 630. 
 
 Heart, 125, 127, 128, 139, 163, 171, 175. 
 Hecaton, 86. 
 Hector, 6. 
 Hedge, Levi, 374. 
 Heidenhain, 615. 
 Helmholtz, Hermann von, 573-58 1 , 6 37-
 
 INDEX 
 
 73i 
 
 Heraclitus, 9, 12, 22, 91, 117. 
 Herbart, Johann Friedrich, 395-415, 
 
 621, 622, 637. 
 Bering, Ewald, 582-596. 
 Hermogenes, 123. 
 Herschell, 587. 
 Herveaeus, 171. 
 Hicks, R. D., 1-13. 
 Hipparchus, 117. 
 Hippon, 9, 117. 
 Hjort, 538. 
 
 Hobbes, Thomas, 147-167. 
 Holberg, 676. 
 Holmes, Peter, 116-124. 
 Homer, 7, 12, 13, 32, 36, 65. 
 Hume, David, 279-312, 486, 643, 646. 
 Huxley, Prof., 646. 
 Hypostasis, 113. 
 
 Ideas, 191-207, 232-246, 299, 313. 
 Ideas, association of, 287-293, 315-330, 
 
 463-504. 
 
 Ideas, dynamics of, 432-447. 
 Ideas, equilibrium of, 397-400, 418, 
 
 443-445- 
 
 Ideas, inhibition of, 439-442. 
 Identity, 253, 291, 298. 
 Illusion, 148-152, 538. 
 Images, 38, 77-78, 91, 92, 148, 495, 
 
 545-546, 553, 650, 725. 
 Imagination, 66-70, 77, 82, 148, 153- 
 
 156, 201, 286-287, 293, 314, 337-338, 
 
 351, 560, 626, 712, 721-726. 
 Immortality, 9, 41-44, 106, 123, 217. 
 Impressions, 279-285, 297,303, 329, 330- 
 Inhibition, 439-442. 
 Instinct, 460, 656. 
 
 Intellect, 93, 113-115, 125-131, 483. 
 Interest, 653, 654, 712. 
 Irrationality, 122-123. 
 Irritability, 459. 
 
 Jacobus, 139. 
 
 James, William, 633-671, 684. 
 Jeppe am Berge, 676-677. 
 Johnson, 502. 
 Jones, Owen, 617. 
 Judd, Charles Hubbard, 697-726. 
 Judgment, 65, 93, 247, 345, 390, 714, 
 724. 
 
 Kaye, Bp., 119. 
 
 Kant, 433, 454. 
 
 Kepler, 563. 
 
 King, Archbishop, 313. 
 
 Knowledge, 160-163, 253-255, 294- 
 
 297, 648. 
 Koenig, A., 579. 
 Komma, 558. 
 
 Ladd, George Trumbull, 545-556. 
 
 Land, J. P., 191. 
 
 Lange, Carl Georg, 672-684. 
 
 Langfeld, Herbert Sidney, 562-572. 
 
 Language, 267, 271, 278, 368, 469, 641. 
 
 Latins, 163. 
 
 Laughter, 127, 128. 
 
 Law, Archdeacon, 313. 
 
 Law, Bering's, 582-596. 
 
 Law, Weber-Fechner, 557-572. 
 
 Lear, 502. 
 
 Leibnitz, Gottfried Wilhelm von, 208- 
 
 228. 
 
 Leontius, 34. 
 Leucippus, 6. 
 Lichtenberg, 608. 
 Light-sensation, 156, 176, 331, 532- 
 
 535, 582-596. 
 Local signs, 545-55". 
 Locke, John, 232-255, 276, 280, 315, 
 
 324, 454, 639. 
 Lotze, Rudolf Hermann, 545-556, 655. 
 Lucretius, 97-105, 118. 
 
 Mach, Ernst, 597-618. 
 
 Machine, 213, 219, 333. 
 
 Magnitude, 71, no, 256, 267-272, 716, 
 
 717. 
 
 Maine de Biran, 448-462. 
 Malebranche, 211. 
 Man, 138-142, 192-196, 313-330. 
 Mantegazza, 669, 671. 
 Materialism, 427, 431. 
 Mathematics, 275, 296, 503. 
 Matter, 50, 108, 143, 144, 239, 334, 693. 
 Maxwell, 578, 579. 
 
 Measurement, psychical, 562-574, 715. 
 Melissus, 213. 
 Melloni, 587. 
 Memory, 202, 221, 286-287, 3 J 4, 337. 
 
 381, 405, 436, 486-490, 694, 712, 726.
 
 INDEX 
 
 Mersenne, 175. 
 
 Metaphysics, 224, 426, 545, 597-610. 
 
 Method, 689. 
 
 Mill, James, 463-482. 
 
 Mill, John Stuart, 463, 632. 
 
 Mind, 97-105, 120-122, 132-135, 191- 
 
 207, 235, 306, 313, 433-44> 463-480, 
 
 505-529, 692, 694. 
 Modes, 192-200, 251, 292-293. 
 Molesworth, Sir William, 147. 
 Molyneux, Mr., 247, 276. 
 Monads, 220-226. 
 Movement, 52, 57, 82, 91, 150, 170, 225, 
 
 246, 263, 304, 328, 377, 550, 707. 
 Mueller, Johannes, 530-544, 579, 597- 
 Munro, H. A. J., 97-105. 
 Muscle, 377, 384, 449, 489, 660, 669, 
 
 709. 
 Music, 165, 228, 411, 487, 558, 561, 648. 
 
 Nature, 130, 194, 208-228, 299, 464, 
 
 530. 
 
 Nerve, 316-320, 416, 538, 542, 573-581. 
 Newton, Sir Isaac, 315, 317, 318, 319, 
 
 503. 
 
 Nous, 8, 1 20. 
 
 Number, 291, 292, 294, 299, 473. 
 
 Nutrition, 45, 48, 51, 53-56, 79, 81, 224. 
 
 Object, 69, 84, 85, 230, 361-367, 373- 
 
 Observation, 249, 305. 
 
 Odour, 341-360, 368, 497, 535, 600. 
 
 Ogilvie, 502. 
 
 Optics, 257, 261, 573-58i. 
 
 Pain, 49, 87, 98, 101, 109, 152, 241, 285, 
 
 313,342-356,530,606,678. 
 Paradise Lost, 504. 
 Parmenides, 12, 213. 
 Parr, Samuel, 313. 
 Perception, 11-26, 54-60, 84, no, 192, 
 
 220, 246-249, 338, 361-367, 412, 416, 
 
 417, 606, 658, 661. 
 Personality, 212, 333, 359, 455-462, 
 
 601-609. 
 Phenomena, psychical, 92, 432-435, 
 
 463-480. 
 
 Philosophy, 16, 209, 290, 297, 300, 462. 
 Physicist, 4, 5, 503, 608, 609. 
 Physiology, 417, 451, 53O-544, 685-691. 
 
 Piderit, 670. 
 
 Plants, 47, 48, 52, 54. 
 
 Plato, 7, 11-44, n6, 117, 118, 122, 123, 
 
 182. 
 Pleasure, 49, 75, 90, 152, 163, 165, 228, 
 
 241, 314, 342-356, 488, 606. 
 Pliny, 211. 
 Plotinus, 106-115. 
 Power, 148, 229-231, 242, 246, 302- 
 
 312- 
 
 Power, muscular, 489-490. 
 Probability, 294-300. 
 Protagoras, 11-22. 
 Psychology, associational, 313-330, 
 
 463-504. 
 Psychology, empirical, 147-167, 232- 
 
 312,432-447. 
 
 Psychology, evolutional, 505-529. 
 Psychology, foundations of, 448-462. 
 Psychology, mathematical, 395-447. 
 Psychology, physiological, 33i~34O, 
 
 530-726. 
 
 Psychology, rational, 229-231. 
 Psychophysics, 53-544, 557-572, 596, 
 
 688. 
 
 Purkinje, 538. 
 Pythagoreans, 6. 
 
 Qualities, 243-246, 299. 
 Quantity, 294, 408. 
 
 Rand, Benjamin, 125-131, 138-146, 
 
 331-340, 416-462, 557-56i, 573-596, 
 
 672-684. 
 
 Rand, Edward Kennard, 229-231. 
 Rationality, 122-123, 138-142, 653. 
 Reaction, muscular, 708-711. 
 Reason, 70-73, 78-80, 130, 483, 643, 
 
 692. 
 
 Reason, sufficient, 224, 230. 
 Reflection, 234-238, 240-242, 252, 285, 
 
 332. 
 
 Reid, Thomas, 361-373. 
 Relation, 249-255, 290-292, 291-301, 
 
 505-510, 523, 621, 648, 650. 
 Relativity, law of, 483. 
 Reminiscence, physics of, 335-336. 
 Repetition, 472, 473, 487. 
 Resemblance, 291, 292, 294, 305, 480, 
 
 481. ...
 
 INDEX 
 
 733 
 
 Resistance, 277, 374-389, 396, 397, 448, 
 
 462. 
 
 Retina, 511, 547-55, 559, 573- 
 Rhythm, 628, 645, 651. 
 Ribot, Th., 684. 
 Ritter, 535, 538. 
 Roman, 202. 
 Rudiment, 419-431. 
 
 Saturation, 577. 
 
 Schopenhauer, 597. 
 
 Science, 32, 50, 160-162, 416-431, 597, 
 
 609, 689, 690, 694, 695. 
 Seebeck, 587. 
 Selby-Bigge, T., 279. 
 Self, 133, 448-462, 598-608, 635, 640. 
 Self-consciousness, 416, 418, 426, 434. 
 Sensation, 49, 56-66, 85, 86, 94, 108, 
 
 230, 234-249, 285,313,316-324,341- 
 
 360, 367-373, 463-482, 520, 530, 544, 
 
 562-574, 597-6i8, 652, 714. 
 Sensations, auditory, 530, 557-561, 
 
 619-632. 
 
 Sensations, muscular, 374-380. 
 Sensations, olfactory, 71, 157, 318, 322, 
 
 341-360, 531-532, 635. 
 Sensations, tactual, 52, 519, 554-561, 
 
 606. 
 Sensations, visual, 256-278, 582-596, 
 
 718. 
 
 Sense, inner, 448-462. 
 Senses, 62, 85, 106, 148-162, 192, 236, 
 
 336, 361-389, 530-544- 
 Sensibility, 316, 445. 
 Sensorium, 317, 318, 537, 540, 543- 
 Signs, local, 545-556. 
 Sight, 16, 62, 256-278, 476, 557-56i. 
 Similarity, 485-486, 490-496, 502-503. 
 Sleep, 19, 46, 153, 231, 279, 322, 533- 
 Smell, 52, 64, 126, 152, 319, 341-360, 
 
 369- 
 
 Smith, Margaret K., 395-415' 
 Socrates, n-44, 85, 121, 142. 
 Solidity, 238-240, 248, 276, 277, 308, 
 
 476. 
 Soul, i-io, 27-46, 84, 106-126, 138- 
 
 146, 168-190, 209-219, 229-231,331 
 
 340,413-415,424-43*- 
 Sound : 61, 71, 292, 369, 372, 520, 557- 
 
 561, 600, 601, 604, 619-632, 652. 
 
 Space, 74, 239, 248, 274, 291, 513, 544, 
 
 545, 548, 552, 556, 621. 
 Space-perception, 380-389, 544, 611- 
 
 618. 
 
 Species, 2, 141, 142, 165. 
 Spencer, Herbert, 505-529, 668, 669, 
 
 671. 
 
 Spinoza, Baruch de, 191-207. 
 Spirit, 210, 226, 227, 445-447, 693-694. 
 Stewart, Dugald, 468. 
 Stimulus, 450, 562-572, 624, 7^6-709, 
 
 717. 
 
 Stoics, 84-88, 117, 228. 
 Striving, 418, 439. 
 Substance, 45, 53, 144, 191-199, 218- 
 
 220, 229, 251-252, 290, 292-293. 
 Suggestion, 389-394. 
 Sumichrast, Frederick de, 341-360. 
 Symmetry, 6 1 6, 617. 
 Synergy, specific, 631. 
 Syrians, 139. 
 Synthesis, 720-726. 
 
 Taine, M., 654. 
 
 Talent, 726. 
 
 Taste, 64, 152, 238, 245, 318-324, 371, 
 
 498,512,521,530,535,543. 
 Tension, 418. . 
 Tertullian, 116-124. 
 Tethys, 12. 
 Thales, 8, 117. 
 Thaumas, 16. 
 Theaetetus, 11-26. 
 Theodorus, 25. 
 Thomas Aquinas, 138-146. 
 Thought, 3, 56-77, 156-160, 490, 643, 
 
 648. 
 Time, 291, 294, 298, 381, 486, 498, 506, 
 
 522, 524, 647. 
 Titchener, Edward Bradford, 558, 685- 
 
 696. 
 
 Tone, 557-56i, 619-632. 
 Torrey, Henry A. P., 168-190. 
 Touch, 51, 52, 239-240, 247, 256, 266, 
 
 273, 370, 376, 380-389, 5U, 530-531, 
 
 557-56i. 
 Traces, 419-423. 
 Treviranus, 544. 
 Truth, 25, 26, 73-75, 93, '59, 160, 
 
 161.
 
 734 
 
 INDEX 
 
 Understanding, 135-137, 207, 232-255, 
 
 445, 722-726. 
 Unity, 140, 209, 216, 241-242, 607. 
 
 Valentinus, 121. 
 
 Van Vloten, J., 191. 
 
 Vaughan, D. J., 27-44. 
 
 Vibrations, doctrine of , 3 1 3-330, 339, 53 7. 
 
 Vibratiuncles, 322. 
 
 Vis repraesentiva, 231. 
 
 Vision, 149, 256-278, 521, 542, 550, 
 
 573-581. 
 Volition, 81, 179, 183, 205, 206, 240- 
 
 241, 483, 486, 496, 606, 697-711. 
 
 Wagner, R., 557. 
 
 Weber, Ernst Heinrich, 544,'557-56i, 
 
 717, 718. 
 
 Weber's Law, 557-572, 717, 718. 
 Weight, 474, 559, 561, 595-59$, 720. 
 Will, 78, 88, 125, 135-137, I45-M6, 
 
 165-167, 207, 240-241, 314, 334, 356, 
 
 446,697-711. 
 
 Wisdom, 112, 159, 213, 225. 
 Wolff, Christian von, 229-231. 
 Wundt, Wilhelm, 669, 670, 687-726. 
 
 Yonge, Charles D., 84-96. 
 Young, Thomas, 573-581, 583. 
 
 Zeno, 84-88, 117, 642. 
 Zenocrates, 117.
 
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