■^O LIBRARY UNIVERSITY OF CALIFORNIA. • Receired V-<^^ EDUC. THE ELEMENTS OF THE PSYCHOLOGY or COGNITION \ Rev. EGBERT JARDINE, B.D., D.Sc. Edin., ]iX-PBIKCIPAL OP THB GEITBRAL ASSEMBLY'S COLLEGE, CALCUTTA, Author of " What to Believe," etc. REVISED AND IMPROVED LO] MACMILLAN & CO. 1884. CHAHLES DICKEWS AXD EVAX3, CBTSTAL PALACE PBES?. '4^<^ V BF3II 1 ssi- EDUC. PSYC;: UBRAi.Y n^l PKEFACE TO FIEST EDITION. The present work professes to be an introduction to a very interesting and important subject of study, — the psycliology of the intellectual part of tbe human mind. It is designed principally for the use of students who are beginning their philosophical studies, and the writer has therefore endeavoured to express himself in as clear and simple language as possible. But while intended primarily for this class of readers, it is hoped that those who have already made the acquaintance of the subject will find something to interest them. The writer is ready to admit that one principal object which he kept before his mind in the pre- paration of the book was to show the inadequacy and unsatisfactoriness of a prevailing system of psychology which may be indicated by the word "phenomenalism.^' At the same time he admits also having received much assistance at various PREFACE. times in matters of psychological analysis from writers who have supported that system. For valuable suggestions regarding the process of reasoning, particular acknowledgments are duo to Mr. Herbert Spencer, who, in his " Principles of Psychology," has given an admirable exposition of the nature of the reasoning process. The author has no intention to deprecate criti- cism of any of the doctrines which he has attempted to establish. The only consideration which he wishes to urge upon the critic is that the book has been written with considerable haste, in order to secure its publication within a certain limited time. And, therefore, there are probably many details which would be altered if a somewhat longer time had been allowed before giving the work a final revision previous to publication. PREFACE TO SECOND EDITION. The author of this little manual of psychology ventures to offer a Second Edition, revised and considerably improved. He hopes that the favour- able reception accorded to the First Edition will be extended likewise to the Second^ and that it may be still more useful as an introduction to a very interesting and important subject of study. Attention is called to the vocabulary of philo- sophical terms at the close of the volume, which will be a valuable help to the uninitiated reader in becoming acquainted with the somewhat un- common phraseology of philosophy. CONTENTS. CHAPTER I. INTBODUGTION. SBCTION" PA6K I. Sources and Arrangement 1 II. Criticism of Sources 6 III. Consciousness . 16 CHAPTER 11. THE ACQUISITION OF PBESENTATIVE KNOWLEDGE. 1. Analysis of Perception 36 II. Analysis of Sensation 41 III. Representation of Sensations .... 54 IV. Sensations as Objects 62 Y. Perception . 76 THEORIES OF PEBGEPTION. I. General Description and Classification 93 II. Descartes . 99 III. Locke 109 IV. Berkeley (1684-1753) . 116 V. Hume (1711-1776) 125 VI. Reid (1710-1796) 139 VII. Kant (1724-1804) . . . . 153 VIII. Modern English Psychology . . , , 158 Till CONTENTS. CHAPTER IV. BEPBESENTA TION. Vkd-R I. Condition of Representation . . . .176 II. Laws of Representation 182 III. Kinds of Representation : Phantasy, Memory, Expectation 189 IV. Imagination in Science and Art . . . .195 V. Imagination in Ethics and Religion . . . 207 A^I. Peculiarities of Representation . . . .211 A^II. Representation of Abstractions . . . .214 CHAPTER V. ELABOBATION OF KNOWLEDGE. I. Predication 224 II. Intuition 228 III. Dependence of Predication upon Intuition . . 234 IV. Implied Predications 237 V. The Class ; the Concept ; the Name . . . 245 VI. Predication again 264 VII. Reasoning Simulating Inference .... 294 VIII. Inference .300 IX. Determining Ground of Inference . . .311 X. The Form of Inference 324 XI. Evidence ; Induction ; Deduction . . . 329 XII. Conclusion 342 Vocabulary of Philosophical Terms .... 347 THE ELEME]!fTS [ PSYCHOLOGY OF COGMTIOI^. CHAPTER I. INTBODUCTIOK Section I. SOURCES AND ARRANGEMENT. § 1. The Psycliology of Cognition forms an important part of the philosophy of the human mind, cognition being one of the three great classes of phenomena which, according to the generally accepted division, constitute the mind. The remaining two classes may be designated the Peelings and the Voluntary Activities. These, however, will not come under our special con- sideration, except in so far as they are involved in the first class of phenomena. Cognition is a general name which we may apply to all those mental states in which there is made known in con- sciousness either some affection or activity of the mind itself, or some external quality or object. The B CHAP. I. SECT. I. Classifica- tion and character of cog. nition. TEE ELEMENTS OF THE CHAP. I. SECT. I, No actual separation of mental •phenomena possible. Sources of knowledge regarding the mind. Conscious- ness. Physical organism. Psycliology of Cognition analyses knowledge into its primary elements, and seeks to ascertain tlie nature and laws o£ tlie processes through which all our knowledge passes in progressing from its simplest to its most elaborate condition. It is necessary for scientific purposes to classify mental phenomena, but it must be borne in mind that in actual con- sciousness there is no possibility of separating the one from the other, and it is frequently difiicult to determine to what class a particular phenomenon belongs. In the earliest or simplest stage of know- ledge it is perhaps difiicult to say whether the phe- nomenon should be classed as a Feeling or a Cogni- tion; and, consequently, it will be necessary in this treatise to consider all those primary elements, of whatever character, which enter as constituent parts into our matured knowledge. § 2. The materials which we shall require in the systematic exposition of our subject are drawn from various sources, but especially the following : — a. Examination and analysis of consciousness. This is the power which every individual possesses of becoming aware of the various feelings and other phenomena which are experienced in his mind. It is the only power by which these phenomena can be directly known or studied, and, consequently, in every system of philosophy it must be appealed to as an authoritative revelation of mental facts. 6. The anatomy and physiology of the physical organism. Without entering into disputed questions it is universally admitted that the powers of the PSYCHOLOGY OF COGNITION; mind are in some way connected with, and depend upon, tlie faculties of tile body, and more especially that the nervous system, with its centre in the ganglia of the brain and its extremities scattered over the surface of the body, is the principal medium of communication with the external world. Whatever may be the value which a knowledge of the laws and operations of this system of nerves possesses, it may cast some light upon the more refined operations of the mind itself. c. The history of human progress or of the re- sults of the continued activity of the human mind. Amongst the most important of these is language. If physiology makes us acquainted with the instru- ment by which the mind operates, the science of language exhibits and analyses the first and most important of the mind^s products. It is only within the last half century that this science has sprung into existence ; but the results which it has already attained are of so great importance in illustrating the history and progress of the human mind and the human race, that the most sanguine hopes may be entertained with reference to the achievements which it is yet destined to accomplish. The progress which has been made in different places and under different conditions in the useful and elegant arts, in science, and in social character and customs, may also afford illustrations of the nature and laws of the human mind. The consciousness which each individual possesses of the working of his own mind may be corrected and enlarged by an observation, of the B 2 CHAP. r. SECT, I. Results of mental activity. Progress in other elements of life. TEE ELEMENTS OF THE CHAP. I, SECT. I. Order of study. 1. Criti. cdsm of materials. gradual and progressive development of the^mind of the nation or race. That such progressive develop- ment has actually taken place^ no one can doubt. The history of religion, of science, of art, as well as of philosophy, is evidence of the fact. To the history of this progress, therefore, the student of philosophy should turn his attention, for in it he will find illus- trations, upon a grand scale, of the operation of mental forces and principles which consciousness reveals to him, upon a small scale, in his own mind. § 3. Before proceeding to the consideration of the special subjects of psychology, it is desirable to take a general view of the order in which they should be studied. In the first place, it will be necessary to examine critically the sources from which facts regarding the mind are derived, in order to determine their value, their bearing upon the questions under examination, and the nature of the information which they are likely to give. The facts revealed to us in conscious- ness, those made known by a study of our physical organism, and the results of human mental activity, constitute different classes of data from which con- clusions may be drawn regarding the operations and laws of the mind. These different classes of facts give testimony of different kinds and of different value ; and it will be necessary both to pursue an accurate method in the examination of the facts themselves, and to see that no conclusions which they do not warrant are drawn from them. PSYCEOLOGY OF COGNITION. § 4. The next step is the analysis of our mental phenomena into their simplest elements. In the maturity of the human mind the feelings, percep- tions, thoughts, and other phenomena are very com- plex in their nature ; and we cannot thoroughly un- derstand them until they have been resolved into the elements of which they were originally composed. Having determined as accurately as possible the original elements of our knowledge, we may discover the manner in which these elements are combined or modified so as to constitute what is called pre- sentative knowledge — that is, knowledge which is immediately presented to the mind without having undergone any process of repetition, or comparison, and without having inferences drawn from it. In this reduction of knowledge to its simplest elements we shall be led to study the relations between these ultimate mental facts and the parts of the physical organism with which they are more immediately connected, and we shall be able to trace the first beginnings of our knowledge of external things. It will be necessary also to study another process, the repetition or representation of the original elements of our mental activity, since this process plays an important part in the perception of ex- ternal and distant objects. § 5. The repetition or representation of the ele- ments of knowledge, introduced as a subsidiary pro- cess in the psychology of perception, must now be studied in its higher and more easily recognised functions as exhibited in phantasy, memory, and CHAP. I. SECT. I. 2. Analysis of present' ative knowledge, and coni' hinationof elements into com- plex pro- ducts. 3. Repre- sentation of mental pheno. mena. THE ELEMENTS OF THE CHAP. SECT. 4. Elaho. ration of knowledge. CHAP. I. SECT. II. imagination. These subjects, and certain problems involved in them, form an interestiag chapter in the study of the human mind. § 6. The last and highest class of phenomena to which we shall require to turn our attention consists of those complex processes of comparison, general- isation, and inference which are employed in the enlargement and elaboration of our knowledge. The study of the products of these processes is the work of the logician. Logic has to do with the results of the mental processes to which we are referring; but psychology is concerned with the nature of the processes themselves as revealed in consciousness. While, therefore, the objects of our study here will, to a certain extent, coincide with those of the logician, we shall look upon them from a different point of view. It will be our aim to discover the nature and laws of our mental activity exerted in the formation of those predications, general notions, and inferences which form the subject-matter of logic. Section II. CRITICISM OF SOUECES. § 7. In this section it is proposed to examine briefly the sources of our knowledge of the mind, for the purpose of ascertaining the kind and amount of evidence which they are likely to give concerning the mind's processes. These sources we have already arranged into three classes — consciousness, the study PSYCHOLOGY OF COGNITION. of tlie physical organism, and the results wliicli follow from the mind's activity. Beginning with the third of these^ as being the most familiar to those who have not devoted much attention to the subject, we may remark that from it we need not expect to obtain much assistance in the study of the more ultimate and elementary phenomena of the human mind. The manifest re- sults of human activity, as seen in language, in mythology, in art, or in religion, are the expression or effects of mental processes of a complex and elaborate kind. They cannot, therefore, throw much light upon the mental problems connected with the first beginnings of knowledge; but they will assist very materially in showing how the more complex mental operations are carried on, how the simpler elements of knowledge are combined and elaborated. Leaving their consideration, therefore, for a future period, we shall examine more carefully the other two sources which we have indicated. § 8. A study of the physical organism is without doubt an important preparation for the study of the mind. But the value of the information which it gives has been differently estimated by different students. All are willing to admit that the connec- tion between the body — and especially the nervous system — on the one hand, and the mind on the other, is of a very intimate kind ; and all should, therefore, agree that the study of the one is an important condition of a complete knowledge of the other. But there are diversities of opinion as to the nature CHAP. I. SECT. II. study of complex mental products. Physical organism : different views of its relation to the mind. TEE ELEMENTS OF THE CHAP. I. SECT. II. (l.)Mind a function of train. of the connection between the movements of the nervous system and brain which are distinctly phy- sical, and the elementary phenomena accompany- ing or following them which are distinctly mental. The following are clearly distinguished doctrines upon the subject: — (1.) It is held by some that the mind is a function of the brain. In order to understand this, we must bear in mind the relation between function and organ in the vegetable and animal kingdoms. An organ is a constituent part of an organised body which has some definite duty or function to perform. The function of the leg of an animal is to walk or run ; that of the wing of a bird is to beat the air so as to enable the bird to fly. The stomach is a large internal organ of the body, whose function it is to contain the food which we swallow, until it has been prepared for being taken into the blood. The liver is another organ, whose function it is to secrete bile, which is poured into the stomach to assist in the digestion of our food. Every organ has got some special work or function to perform in the body to which it belongs. In the same way, it is argued, the brain has a function to perform in the animal system, and that is to produce the various mental phenomena of which we are conscious. And, acting upon this hasty and crude hypothesis, a set of visionary speculators called phrenologists have thought that they could learn all about the mind, its character, and its laws, by the study of its organ, the brain.* * This is the theory of M. Comte, and some of his followers. F8YCH0L0GY OF COGNITION. There are many objections to this hypothesis^ of which we offer the following. The functions of all the organs with which we are acquainted are perceived by us either as some material product or some mode of motion. We are able to examine both the organ and the function as ordinary physical phenomena ; both the organ and the function are made known by perception through the senses. But in the case of the brain^ the organ is indeed capable of being examined as we examine any other physical organ — by external observation aided by the employment of the dissecting knife. And if we consider the brain as the centre of nervous force by which the muscles of the body are made to contract, we are able to perceive a function of the brain in its result — ordinary muscular motion. But mental phenomena are directly perceived only by consciousness, and are entirely different in kind from any of the functions of physical organs with which we are acquainted. Again, it is admitted by comparative physio- logists that there is a much closer resemblance between the nerve-systems of some animals and that of man than can be made out between the mental o])erations of the former and of the latter. The brain-ganglia of some of the anthropoid apes are exceedingly like those of man ; but between the mental activity of the one and the other there is an impassable gulf ! The organs are very similar; the so-called functions are essentially different. The absurdity of this hypothesis will be still CHAP. I, SECT. II. Ohjections. 10 TEE ELEMENTS OF THE CHAP. I. SECT. II. (2.) Mind and body tivo inde- pendent substances. farther apparent from a consideration of the fact that the alleged function — the mind, actually governs the organ — the brain. The mind con- sciously determines to act in a certain way, issues its commands to the great centre of nerve-force^ the brain, and the nerves and muscles immediately act in obedience to the mandate. The same objections apply to that modification of this theory which makes mental phenomena a secretion from the brain, analogous to the bile and other secretions of the glandular organs of the body. Hence there is a strong presumption, which may be confirmed as we advance, against the hypothesis that the relation between the nervous system and the phenomena of the mind is identical with, or even analogous to, that between ordinary physical organs and their functions. Consequently, although a knowledge of the nervous system may be of im- portance to the study of mind, we can attach to it at present but a subordinate degree of importance. (2.) A second theory of the relation between the mind and the body may be described in the follow- ing manner. The mind and the body are two- entirely different substances possessing entirely different qualities. The mind has been brought into connection with the body, inhabits the body, and uses the body as its instrument of carrying out its purposes and communicating with the ex- ternal world; but they are in nature so entirely different, that there is, and can be, no truly causal PSYCHOLOGY OF COGNITION. II connection between tlie phenomena of the one and those of the other. An impression upon an organ is only an occasion on which, by some mysterious power, a sensation is produced in the mind. So the occurrence of a volition or determination in the mind is only an occasion on which, by divine in- terference, a movement is excited in some of the muscles of the body. The connection between the mind and body is only accidental, and might have been otherwise. The one is now inhabiting and employing the other, but has an existence really independent of the other ; and our knowledge of the one cannot be increased to any material extent by a study of the other. Those who hold a theory such as this attach very little importance to the stady of the brain and nervous system as subordi- nate to psychology. It is a degradation of the mind to suppose that any light can be thrown upon its workings by a study of its humble habitation and instrument. Consciousness, therefore, and conscious- ness alone should be resorted to by the student of psychology. A theory such as this was held by the older followers of Descartes and the older adherents of the Scottish philosophical school. But there are certain considerations which will prevent us from adopting it as an hypothesis to guide us in our studies. In the first place, the student of psychology has nothing to do with the so-called suhstances of mind or matter ; he has to study only the phenomena, the sensations and the qualities which consciousness CHAP. I. SECT. II. Cartesian theory. 12 TEE ELEMENTS OF THE CHAP. I. SECT. II. {3.) Mental and cere- hral events form two partially co-ordi- nate series whose re- lations are not accu- rately known. and perception make known to him. And, again, it is unscientific to advance to tlie study of the mind with certain preformed and crude notions regarding its nature, its independence of matter, and other things ; although it is quite possible that more or less definite conclusions regarding these questions may be reached as the result of study. As far as our experience goes, the mind is most intimately connected with our physical organism, and it appears to be the duty of the psychologist to take into account every fact bearing upon his subject, admitted to exist, and learn from it as much as possible. Moreover, it lies within his sphere to study only those phenomena which manifest themselves in our present conditions of existence, and not to speculate or make assertions regarding what might be under other conditions. (3.) A third theory respecting the connection between physical and mental phenomena regards them as simple antecedents and consequents, without predicating anything concerning the difference in their nature except in so far as may be learned from actual observation. A certain physical movement or nervous vibration takes place ; it is followed by a sensation. A certain volition is determined in the mind ; it is followed by a muscular movement. The psychologist, aided by the physiologist, may legiti- mately endeavour to discover what particular phenomena of a physical kind always precede or follow certain phenomena of a mental kind, in what order the two series of phenomena occur_, and other PSYCHOLOGY OF COGNITIOX. 13 facts regarding them of a similar kind. But on the other hand, it is not legitimate to assume, without satisfactory reasons, that every mental phenomenon has a physical or nervous antecedent, any more than it is legitimate to take for granted that every organic action is the result of some conscious mental antecedent. As physiologists tell us about certain organic actions which take place in the body alto- gether independent of any mental determination, so there is an d jpriori probability that there are mental activities which are not connected with any particular physical movements. This probability is abundantly confirmed from a study of certain classes of mental phenomena which, from their nature, cannot have mere physical antecedents. Primitive judgments are of this character. The assertion that two lines are equal, that white is different from green, that thunder follows a flash of lightning, express mental judgments which have for their objects certain things given in sensation, but are not the causal consequents of these things. The mental judgment is the independent action of the mind regarding the relations of certain objects perceived. Moral judgments are also of this character. A desire, appetite, or passion takes possession of a person ; originating perhaps in some physical condition, it seeks to bend the will so as to secure possession of its object. But conscience intervenes, pronounces the desire, appetite, or passion to be CHAP. I. SECT. II. Mental events may he without physical antece- dents. 14 TEE ELEMENTS OF TEE CHAP. I, SECT. II. Conscioua- wrong, and forbids its object to be sought after. Tliere you have a desire originating in physical antecedents, strongly influencing the mind towards action ; but the intervening moral judgment which pronounces the contemplated action to be wrong and peremptorily forbids it, from what physical antecedent can it proceed? It powerfully and with authority resists the course to which the desire, born of physical conditions, would lead, and hence it cannot be the natural consequent of these antecedents. This third theory of the concomitance of the physical and the mental series of phenomena is the one which appears to us nearest the truth as far as we know it. It asserts nothing regarding the relations of mind and matter except what is discovered or inferred from actual observation ; nothing regarding the possible independence of what are actually united. It must be limited, however, to those phenomena in each series which are dis- tinctly shown to have a connection of antecedence or consequence with phenomena of the other series. It is illegitimate to assume that because a certain number of facts in the two series are concomitants^ therefore all are so. And it is also illegitimate to assume that because certain facts of the one series follow facts of the other, there must there- fore be any essential connection between them. § 9. We come now to refer to that source of knowledge regarding the mind which, though last in order of consideration, is first in importance. It I PSYCSOLOGY OF COGNITION. 15 is by consciousness only tliat we can become directly acquainted witli mental pbenomena. As those phe- nomena are called physical which can be perceived by the senses either alone or aided by artificial contrivances such as the microscope, so those phenomena are called mental which manifest them- selves in consciousness. Since, therefore, conscious- ness is the only means by which we can become directly cognisant of mental phenomena, it follows that the study of the facts revealed in consciousness must always be the principal method of obtaining psychological knowledge. This study, however, as it is one of great importance, is also one of great difiiculty. The art of reflecting upon our own mental operations is one which requires a great deal of at- tention and cultivation in order that we may become proficient in it. This depends partly upon the fact that the energies of human beings are first, and usually continue to be, directed outwards to other persons and external objects. It requires an effort to turn the attention inwards to the facts of con- sciousness ; and hence in Greece men had attained to a high state of civilisation, and acquired a great deal of knowledge regarding external objects, before any attempt was made to examine and analyse the phenomena of the mind. Another cause of the difficulty of reflection is the great complexity of the phenomena made known in consciousness. This complexity is twofold. In the first place, phenomena are complex from the fact of a great many of them occurring simultaneously or in CHAP. I. SECT. II. i6 THE ELEMENTS OF THE CHAP. I. SECT. II, Method of studying phenomena of con- sciousness. Its general character and ele- ments. immediate succession ; and it is difficult to separate tliem the one from the other, so as to ascertain their mutual relations. And in the second place, certain mental actions which seem at first view to be quite simple are in reality very complex in their origin. It is frequently a matter of great difficulty and delicacy to analyse the history of the mind's ability to perform such actions. We are apt to suppose that, because we can perform them easily and readily now, we were always able to do so ; and it is difficult to conceive the condition of our minds when we had not our present ability. § 10. As consciousness is the original and only reliable witness testifying to the facts of the human mind, it is manifestly important that the student should know how to examine this witness, and what kind of facts it might be expected to bear witness to. And in the next section we purpose introducing the student in a general way to the character and elements of consciousness, its legitimate sphere, and the different methods by which its testimony may be interpreted. Section III. CONSCIOUSNESS. § 11. We give our first attention to the general character and elements of this most important source of knowledge regarding the mind. Con- sciousness is the most general phenomenon of the human mind, and all particular phenomena are PSYGEOLOGY OF COGNITION. 17 but its states or modifications. No mental phe- nomenon can take place whicli is not, as it were, a link in the general train of our conscious life, a particular form of consciousness. Hence it is impossible to define consciousness in the proper sense of the term, that is, to refer it to a higher class of phenomena of which it is a species. Every particular mental phenomenon involves conscious- ness; and, on the other hand, there can be no general consciousness which is not some par/- ticular phenomenon. Psychologists analyse 4fc^ sciousness into the following elements : — A cognising or knowing subject; a recognised o? known modification ; and a recognition or know- ledge by the subject of the modification. Thus consciousness, or immediate knowledge is, in reality, a relation between two things, — the knowing subject and the known modification or phenomenon. This relation and the terms of it are worthy of very close examination. The first term of this relation is the knowing subject, the self or ego; the second term consists of the presentations and representations which are known. With reference to the first of these terms it is manifest that it cannot be itself a phenomenon ; we could never say that one sensation knows another, or that a thought is aware of a volition, or that any single mental phenomenon cognises any other. It would seem equally absurd to say that the whole collection of phenomena which constitutes our consciousness at any one time knows any .xs^ ¥r^_ Ti^-^ CHAP. I. SECT. III. The ego. i8 TEB ELEMENTS OF THE CHAP. I. SECT. III. particular phenomenon of the series; or that the whole of our past and present conscious life con- sisting of all past and all present phenomena cognises any phenomenon now in consciousness. Every single phenomenon is hnown, is an object of knowledge ; and it is impossible to invest the whole aggregate of phenomena with a power the elements of which are not possessed by them separately. Still further we cannot, by generalisation, from all the past and present aggregate of mental pheno- mena, obtain an element which can be considered identical with the first term of the relation we are examining. Suppose that, from all past and present mental phenomena, we abstract and generalise Feeling itself, we may have here the highest mental abstraction we can reach, but it is not the self. Thus we set aside three doctrines which may bo held regarding the character of the first term of the relation of knowledge, the knowing subject : — (1) That the subject of consciousness is some particular phenomenon of consciousness; (2) that it is the whole aggregate of mental phenomena past as well as present ; (3) that it is some element or characteristic of the mental phenomena, ab- stracted from particulars, such as Thought or Feeling. All of these propositions we reject, be- cause it is inherently absurd that a single phe- nomenon, or an aggregate of phenomena, or an abstraction from phenomena, should exercise the function of Icnowing, which we are conscious of possessing. There is an element in the relation of PSYCHOLOGY OF COGNITION. 19 immediate knowledge which makes it impossible to explain that relation as existing between mental phenomena simply, or between any combinations of mental phenomena or any abstractions from them. § 12. A common man speaking of his mind or feelings would say " my mind,' or *' my feelings J' He would say ''I thought so-and-so/' or '^ J felt such a sensation/' or " / was conscious of this smell or that sound.'' In short, every one thinks and speaks of himself as a person not to be identified with his body ,11 or the series of phenomena which make up what he calls his mind. This reference of all one's feelings and thoughts to self is called self- consciousness. The idea of self-hood involves the belief that "I'' who am conscious of feelings at the present moment am the same identical being who was conscious at a past time of those feelings which "I" remember. This permanence of self in the midst of successive and diverse sensations is the essential element of personality. The idea of self is not that of the sum of the series of feelings which constitute our general consciousness, because it is absurd to speak of the aggregate of a series of feelings being conscious of any one of themselves. Nor is it that of Feeling in general abstracted from particular feelings, because it is absurd to attribute to this or any other abstraction the function of conscious knowledge. In the relation of know- ledge there is implied a kind of opposition be- tween self and the sensations of which seK is G 2 CHAP. I. SECT. III. A' \ 20 THE ELEMENTS OF TEE CHAP. I. SECT. III. TinowaUe. conscious. Sensations past, present, and expected are all referred to self as tlieir possessor and subject. Self is tliouglit to be the imity in tlie midst of diverse kinds of sensations, tlie permanent element in the midst of transient and successive sensations, the one conscious subject in the midst of many Jcnown objects. In " self therefore we have the subjective term of the relation of knowledge ; but this term of the relation is so peculiar and remarkable that we must bestow some more attention upon it. We have said that it is not a phenomenon, and it cannot, in any way, be phenomenised so as to become Icnown. The function of self is to hiow, and although, in the very act of knowing, a phenomenon arises, yet it is impossible for that which knows to set itself over against itself as object and thus become known. Self is the universal relative of all objects, — a something separating itself, as it were, from the phenomena of general consciousness and converting them into objects, but incapable itself of becoming an object. This peculiarity of self makes it the most intractable and puzzling element of our conscious existence. Unknown_, but all-knowing, it emerges, as it were, from the midst of the endless variety of phenomenal consciousness, asserting its freedom from phenomenal law, and offering the great miracle of the life with which we are endowed. It is absurd to attempt a scientific definition or exposition of the unknown ; but we have the power of studying its function conscious activity^ and through the study of this function alone can we PSYCEOLOGY OF COGNITION. 21 learn anything about tlie nature of that which is conscious. § 13. The function of the subject of knowledge is really the same as the relation between the subject and the objects of knowledge. And it is manifest that this relation must be different from other rela- tions with which we are acquainted, since the sub- jective terra of it is different from any object of our knowledge. Moreover the terms of the relation, under present conditions, are insejparahle, because the phenomena which we know are themselves comprehended in and to a certain extent identical with the act of knowing. When we feel a smell, the act of feeling and the smell itself appear to be, as it were, different sides of the same phenomenon. When we attempt, therefore, an examination of conscious activity as seen in cognition we cannot very well separate that activity from its objects. We describe the function of self in cognition as conscious activity in order to distinguish it from the objective or passive element in phenomena. Knowledge is not the reception of images or impressions from without; it is essentially an activity of self in relation to things which are not self. This activity is perhaps best described or rather indicated by such terms as assertion, judgment^ or predication. We are conscious of a loud noise ; in the act of consciousness there is involved the assertion of the existence of the sound. We are conscious of two varying sensations ; we assert that they differ from one another. We are conscious of CHAP. I. SECT. III. Its functions. 22 THE ELEMENTS OF TEl CHAP. I. SECT. III. Methods of interpre- ting con- sciousness. (1.) Psy. cJiological or induc- tive. a particular smell, colour, figure, aud taste ; we assert — this is a rose. Now without this mental assertion there is no knowledge; the mere appearance in consciousness of some phenomenon which does not call forth a responsive activity is not knowledge. We have therefore in this assertion — this conscious activity indicated by the term assertion — the essential element of that relation existing between subject and object in cognition. There is a particular feature of this relation of great importance which we may indicate by the term ohjectification. It is essential to knowledge that the object should be put over against the subject, — that the phenomenal activity should be discriminated into subjective and objective elements. This creation of an opposition or antithesis between subject and object, called ohjectification, is perhaps a result of the conscious activity before described as assertion, or is perhaps identical with it ; but it is at least essential to every act of cognition. § 14. There are three leading methods which psychologists have employed in the interpretation of consciousness, which inay be termed respectively the psychological or inductive, the critical and the psychogenetical. According to the first of these methods, particular phenomena of consciousness are subjected to study, and classified according to their resemblances or differences, and from them general laws of thought are derived. Many cases of causal connectiorij for example, are observed, and from them there is generalised the great principle PSYGEOLOGY OF COGNITION. 23 that every event has a cause. Similarly, many material objects are perceived to be extended, and it is concluded, by induction, that all material things are extended, or are perceived as occupying space. Against this method of interpreting con- sciousness it is objected that it is incapable of explaining the element of necessity which is in- volved in many mental products or laws. Induction alone can only lead to a principle which is generally and probably true ; but there are principles in the human mind which are universally and necessarily true. For example, all men not only believe, but must believe, that every event has a cause; all men not only perceive, but must perceive, phenomena under the relations of time and space. Now this element of necessity, it is alleged, does not and cannot arise from an induction from experience. And it is urged by many psychologists, after Kant, that induction alone cannot account for all the facts of our conscious life. These psychologists employ criticism J by which they discriminate the phenomena of consciousness into two classes : those which are contingent, the results of mere experience ; and those which are necessary, and therefore not the results of experience, but rather the d priori con- ditions of experience. By this critical examination of the simple facts of consciousness they are able to account for the elements of necessity and uni- versality in the more complex products of conscious life, while they claim the right of employing the in- ductive method also wherever it may be applicable. CHAP. I. SECT. III. (2.) Criti- cal. 24 TEE ELEMENTS OF TEE CHAP. I. SECT. III. Necessity from asso- ciation. § 15. The advocates of tlie psychological method object to the critical, that necessity and universality do not of themselves render it certain that a mental fact is original; complex and derived facts, or phenomena, may also be characterised by necessity. Hence, before we accept any fact or phenomenon as an original and simple datum of consciousness, we must examine into the character and source of its necessity. There is a necessity which results from experience, and which consists simply of an inseparable association; and, in fact, all necessity may result from the application of the laws of association to phenomena. And those who make use of the psychological method try to show that all mental products are the results of experience and association. Now there can be no doubt that the laws of association play a most important part in the forma- tion of the complex contents of our consciousness. Phenomena do not appear in consciousness in an accidental or random order, but there is a mutual connection between them of such a nature that they serve to bring one another before conscious- ness. When two mental phenomena have been experienced at or about the same time, a bond of connection i"s formed between them, so that after- wards if one of them is repeated the other is likely to be represented. This link of association between mental phenomena appears to be altogether inde- pendent of volition ; the associated idea of any particular phenomenon appears in consciousness I PSYCHOLOGY OF COGNITION. 25 without any effort of ours, or even in spite of efforts to avoid thinking about it. Illustrations of this association of mental phenomena will readily occur to any one. We have once visited a house, and at the time of our visit something of particular interest to us has occurred. If we ever again visit the house, or even have our thoughts directed to it, the idea of the interesting fact obtrudes itself upon our attention. The various laws by which phenomena are associated together have been suf- ficiently investigated and are well known. We need not therefore refer to them, but shall proceed to point out a distinction of importance with refer- ence to our present study. § 16. We have to distinguish between what is properly a mental association and an ohjedive con- nection. When two or more phenomena have been once or frequently presented together in conscious- ness, they become connected in representation. But there are two different cases to be considered. Two different phenomena may be, upon one or more occasions, connected together in presentation, but may afterwards become objects of consciousness separately. This we may call the case of the asso- ciation of separable phenomena. On the other hand, two or more phenomena may be so connected together that the one is never presented except in connection with the other, and the association in this case is an association of inseparable phenomena. And we must be careful to discriminate between the distinction which we have here drawn between CHAP. I. SECT. III. Lnportant distinc- tion. 26 THE ELEMENTS OF THE CHAP. I. SECT. III. separable and inseparable plienomena and another distinction which is considered of great importance by psychologists, — the distinction, viz., between separable and inseparable associations. There may be an inseparable association of separahle pheno- mena; but as a matter of course, when the pheno- mena are inseparable in presentation, the association of the representations is inseparable also. There are many familiar instances of an inseparable asso- ciation of separable phenomena ; a book, a watch, a trinket of any kind, which has been presented to us by a dear friend becomes, in our mind, inseparably associated with the idea of that friend. But quite different from this is the inseparable association of phenomena which are inseparable. Let us study a case. In our experience we have never been conscious of colour except in connection with extension. No matter how far back in our lives we attempt to reach by the aid of memory, we are incapable of discovering the slightest trace of the possibility of a separation between the two phenomena. We do not remember ever to have seen a colour which was not extended, or an extended figure which was not in some way coloured. Nor is there any indi- cation in history or in language of the existence of any race o"f human beings in whose minds there was ever conceived the possibility of such a separa- tion. And since the presentation of colour is always combined in our experience with that of extension, it follows as a matter of course that the representa- tions also are always combined. PSYCHOLOGY OF COGNITION. 27 § 17. This distinction between an inseparable sub- jective association and an association of objectively inseparable phenomena is one of great importance. When phenomena which are only occasionally pre- sented together have an affinity for one another so as to cling together in representation, the associ- ation is truly and only mental. The possibility of their being separated in presentation shows that their synthesis in association is only a mental one, or at least that the objective union is only acci- dental. But, on the other hand, when phenomena are always united in presentation and can never by any means be separated, their synthesis is not only or even chiefly mental. The objective inseparable connection is that upon which the subjective asso- ciation depends. It constitutes a different kind of connection from that which is simply subjective. There is such a decided difference both in degree and in kind between the mental synthesis which we form between two phenomena which have acci- dentally been brought into contiguity, and that synthesis which exists between two such inseparable phenomena as extension and colour, that no person who has not a particular theory to support, would ever place them in the same category. The inse- parability of phenomena in presentation leads, no doubt, to their inseparability in representation ; but it also leads to something else, and that is, to the conclusion that the synthesis which binds them together is not a subjective one at all. Another phase of the same distinction is found CHAP. I. SECT. III. 28 THE ELEMENTS OF TEE CHAP. I. SECT. III. Special and uni- versal as- sociations. in the distinction between associations wliicli are peculiar to individuals and those which are common to all mankind. All mental associations depend upon the experience of the individual in whose mind they have been formed. Peculiar experi- ences will therefore produce peculiar associations. Experiences common to all will result in associa- tions common to all. In different zones of the earth^s surface and in different countries there are many differences of climate^ landscape, means of living, habits and customs which give rise to very varied mental associations. The character of the seasons in India, in Britain^ and in Canada presents striking differences, and^ in the minds of the inhabitants of these countries respectively, there are consequently very different ideas connected with each of them. The word "water," for example, in the torrid zone, is always asso- ciated with fluidity as one of the characteristic qualities constituting the denoted object. But in the temperate and frigid zones, where water frequently assumes a solid form, fluidity is nob uniformly associated with the word. Many other examples of variable associations might be given. On the other hand, with the word "air^' there are always asS"ociated the peculiar sensations or ideas connected with respiration. "The air which we breathe^' is a phrase which may be universally employed to express the experience of mankind, the reason of course being that, in our present state of existence and with our present physical constitution, FSYCEOLOGY OF COGNITION. 29 the breathing of air is an essential condition of life. This association of the word " air '^ with the idea of breathing is quite as inseparable as any association which we could name. It is, moreover, an association formed in the minds of all men without exception; but there are important differences which we shall note between this and other inseparable associations. § 18. We have just considered two associations, one of them variable and the other invariable and universal, but both being associations connected with particular objects of our knowledge. The qualities or ideas associated are relative to or repre- sentative of particular complex sensations depending upon our present physical constitution. But if we consider the connection between extension and colour we shall be able to note an important difference. The qualities to which we referred as associated with air and water were simply a com- bination of complex sensations objectified; but here we have a sensation '' colour ^^ associated with some- thing which is not a sensation. Extension is neither a sensation nor any combination of sensations, but a certain relation which is seen to exist between objectified sensations, or a form which is perceived in connection with a single sensation. And although the mental association between azV and breathing may be quite as inseparable and universal to the human mind as that between colour and extension^ yet we would never place the objective connection between the first pair in the same CHAP. I. SECT. III. 30 THE ELEMENTS OF THE CHAP. I. SECT. III. category as that between the second pair. The connection between air and breathing is determined to our minds by the peculiar circumstances in which we are placed as physical beings, and we can easily imagine other circumstances in which this connec- tion would not exist. But the relation between extension and colour, although neither more objective nor more necessary than the former is determined by the constitution of our minds with reference to external objects, or the constitution of external objects with reference to our minds. Hence, since we are unacquainted with any other forms or laws of knowledge except our own, it is impossible for us to conceive that any intelligence could be cognisant of colour without extension ; or to state the same thing more abstractly, it is impossible for us to conceive that any intelligence could be cognisant of phenomena except in the relation of difference and co-existence. Thus the connection between extension and colour is characterised by an absolute universality with reference to all in- telligence as far as intelligence can be understood by us; while that between air and breathing has only a contingent universality with reference to beings who may possess bodies constituted as ours are. We have endeavoured to show that the connection between extension and colour is not a case of mental association and cannot be resolved into association. Objectively the two things are absolutely inse- parable ; and subjectively the relation of extension PSYCEOLOGY OF COGNITION. 31 depends upon the primary relation of co-existence whicli we have seen is an a ^priori condition of our constitution as capable of knowing. But if this doctrine be correct, we have here an original fact of our consciousness which the psychological method of Mr. Mill fails to interpret. And until this method explains satisfactorily the inseparability of colour and extension both objectively and sub- jectively, we cannot admit that it is adequate to the interpretation of all the facts of our consciousness. This case of inseparability is only one of those which might be adduced as being insoluble by the psychological method. We have chosen to examine it thus fully because it is perhaps the most im- portant. And as, until the above doctrines are overthrown, the psychological method must be considered unsatisfactory, we shall now proceed to the consideration of another method, the Psijcho- genetical. § 19. Those who adopt this method admit that there are mental facts and products which cannot be explained by the principles of association. Neither the form nor the matter of our knowledge is the result of our individual experience merely. We are born with a certain constitution, mental and physical, and the nature and extent of our subsequent acquirements in knowledge and practi- cal ability depend upon our inherited constitution. In other words, it is admitted that individuals possess certain d priori principles and tendencies by which the phenomena of their consciousness are CHAP. I. SECT. III. ll^X-Q^ 5^ Mm I (3.) Psy. chogeneti- cal. 32 THE ELEMENTS OF THE CHAP. I. SECT. III. Objections. determined and governed. This admission, made by such psychologists as Herbert Spencer and G. H. Lewes, is a tacit acknowledgment of the essential truthfulness of the position held by those who have adopted the critical method. But, while admitting this, the psychogenetical method attempts to trace the origin of the a priori conditions and principles of our nature to a very remote source. The accumulated experience of the past ages of human history, as well as of the past ages, countless in length and impenetrable to human knowledge, of brute history, is called upon for an explanation of the origin of that physical, intellectual, and social nature with which we are born into the world. It is assumed that lower living forms develop themselves into the higher, that the ex- perience of individuals and races gradually produces organic changes which are transmitted to successors, and that thus, by the natural transmission of organic structures produced or modified by incessant ex- perience, all the higher forms of life and mind have been produced. An adequate examination of this ambitious method would carry us far beyond our allotted space and our object; but we offer the fol- lowing observations with reference to it. 1. The "problem attempted by this method is practically an impossible one. We are not able to trace the series of changes asserted to have taken place. It cannot be established that ex- perience gives rise to the structural changes in the organism said to be the result of it. The pheno- PSYCHOLOGY OF COGNITION. 33 mena requiring to be studied in a satisfactory employment of the method are too remote from possible observation to be used as the foundation of a science. Even if we attempt to study the organic changes produced by experience in human beings now living we cannot succeed; and any dogmatic assertions made regarding them must be rash and vain. Much more must this be the case with reference to races of men and animals which existed in a remote past antiquity. Consequently the researches carried on in accordance with this method are nothing better than ambitious and perfectly uncertain speculations. 2. Against the fundamental assumptions of this method it may be alleged that mental phenomena do not, in some cases at least, correspond to organic structure. It is now universally admitted that the brain and nervous system of the anthropoid ape is exceedingly similar to that of man, whereas the mental functions of the latter are almost infinitely in advance of those of the former. This fact is quite inconsistent with the fundamental assumption of the psychogenetical method. 3. If experience in past ages has given rise to necessary truths and a priori conditions of thought and knowledge, we might reasonably expect that these a priori principles should continue to be pro- duced in our own age. While it may be admitted that some particular tendencies and abilities may be acquired and transmitted, it has not been shown that the essential and universal laws of human CHAP. I. SECT. III. 34 TEE ELEMENTS OF THE CHAP. I. SECT. III. intelligence have suffered the slightest change since man came into being. From these considerations we should be inclined to reject the psychogenetical method as imprac- ticable, possibly false, and quite incompatible with that desire to attain certain conclusions which ought to characterise men of science. And we are now driven back to the critical method of Kant and Hamilton which we adopt as correct and adequate, with the following reservations : 1. The adoption of this method does not commit us to all the results of criticism which those who have hitherto employed the method have reached. It may be that mistakes have been made in dis- criminating between facts of consciousness as original and acquired, simple and complex, that some phenomena have been regarded as original and simple which are really derived and complex. But this admission does not detract from the value of the method. 2. The adoption of the critical method does not prevent us from making use of the principles of association as far as they are applicable. It is not an essential principle of this method that anything which is now found to be necessary must be an original necessity of intelligence. And if any necessity of thought or knowledge can be explained by the laws of association or any other principles of experience, it ought unquestionably so to be ex- plained. But the critical method insists upon distinguishing between such explicable necessities PSYCHOLOGY OF GOGNITION. 35 of thought, and an inexplicable residue of necessities which^ from their nature, must be taken as d ^priori and founded in the constitution of our intelli- gence. 3. The critical method, while it looks principally to the phenomena of consciousness as the materials with which it has to deal, is not inconsistent with a careful study of the organism and cosmic forces and laws in so far as these may throw light upon the problems to be solved. In this section, for the sake of the completeness of our study of the subject, we have been led into a discussion, which at this stage of the student^s pro- gress can scarcely be very intelligible to him, that is, if he be new to the study of psychology. We should recommend, therefore, a brief and general study of the section, upon first reading, to be followed by a more careful examination after- wards. CHAP, I. SECT. III. D 15 36 THE ELEMENTS OE TEE CHAP. II. SECT. I. Example ofanalysis. CHAPTER II. TEE ACQUISITION OF PBE8ENTATIVE KNOWLEDGE. Section I. ANALYSIS OF PEECEPTION. § 20. By way of introducing tlie problems con- nected with this subject, let us begin with a par- ticular example. Suppose that we see a flowering tree in full bloom a short distance in front of us. The cylindrical trunk, the branching stems, the foliage, the numerous clusters of flowers form a very beautiful object to the eye. The flowers are odorous ; the wind is blowing from the direction of the tree towards us ; and a pleasing perfume is wafted into contact with our olfactory nerves, giving us the sensation of an agreeable smell. The wind which brings the perfume of the flowers causes the innumerable leaves of the tree to flutter, and thus produces that pleasant murmuring sound of fluttering leaves with which every one is familiar. The tree, we have supposed, is at a short distance from us. This means, that if we walk a short distance towards the object which we see, we shall be able to touch it. Acting upon this hint, we advance and touch one of the leaves of a branch hanging near the ground. A slight sensation is PSYCHOLOGY OF COGNITION, 37 felt on tlie point of the finger. We touch the trunk and press against it ; it resists our pressure; it is hard. We move our hand over its surface, pressing lightly against it, and discover that there are inequalities in it, the tactual sensation being here and there interrupted ; in other words, the bark of the tree is rough. Our curiosity is not yet satisfied, and so we pluck a cluster of the flowers, put one of the coloured petals into the mouth and chew it ; it is pleasant to the taste. All our senses having been thus brought into exercise, we take our seat upon a mossy hillock near by, and reflect upon what we have been doing. § 21. The complex activity which has given us a more or less complete knowledge of the qualities of the tree is called perception. And this perception is, of course, most complete when, with each of our senses, we have become directly acquainted with that quality of the tree which is capable of being perceived by it. Three of these qualities we have seen are capable of affecting us at a distance — the colour, the smell, and the sound. The remaining two, the touch and the taste, require, as their con- ditions, that we shall advance to the tree and bring parts of it into immediate contact with our organs of sensation. Thus, touch and taste of themselves bring to our knowledge objects at no greater dis- tance than we are able to reach our hands — the latter, indeed, at no distance at all. Sight, smell, and hearing give us a knowledge of colours, odours, and sounds, and these qualities are perceived as at CHAP. II. SECT. I. Analysis explained. 38 THE ELEMENTS OF THE CHAP. II. SECT. I. a distance from us. But a little reflection will con- vince us that tlie sensations whicli we experience througli these senses are really felt within our own bodies, although apparently the causes of those sensations exist at a distance from us. The colour which we perceive appears, as it were, spread over that object whose different other qualities we smell, hear, touch, and taste. But we observe that its apparent colour varies according to the amount and kind of light which is thrown upon it ; and scientific men assure us that the white light of the sun is compounded of three or seven elementary colours ; that green leaves absorb all these colours except green, which is reflected from their surface, and, falling upon the retinae of our eyes, produces the sensation of greenness ; so the sensation of any other colour is produced by the light from that colour falling upon our organ of sight. Thus we learn from our own reflections, or from the discoveries of scientific men regarding light, that all sensations of colour are felt in and by means of our eyes. These sensations are what we directly know, because we are conscious of them. And as we have seen that by consciousness we can only know what is imme- diately present to our minds, it follows that the perception of the tree as at a distance must be accomplished by means of some other power than consciousness. A similar line of reflection or observation will lead us to the conclusion that the sensations of smell and sound also are felt within, and by means of, our PSYCEOLOGY OF COGNITION'. 39 organism. And the sensations of touch and taste are, from their nature, seen at once to be organic, since their objects must be in immediate contact with the senses. Thus we see that what we may call a complete perception of the tree may be resolved into sensa- tions of the several senses and the elements of distance in space or the occupation of a certain part of space without us. But we may say that we perceive the tree, although all our senses are not actually engaged ; if we simply look at it from a distance we are said to perceive it. Although in this case, we see only a certain coloured figure which we believe to be at a distance, yet we know that if we pass through the intervening distance we shall be able to touch a hard and rough object and taste the green leaves. And in the same way, if our eyes are shut and we smell the perfume of the flowers, we know that we are not far from some object which we might see, and touch, and taste. So, likewise, with all our senses. If by any one of our senses a sensation is experienced, we immediately conclude that there is some object outside of us which is capable of affecting our other senses ; and our per- ception of the object is more or less complete, according as more or fewer of our other senses have been affected by it. Now, there is nothing more certain than that by each sense we can have only that kind of sensation which is proper to it. By sight we can only know colour, by smell only odonr, by hearing | CHAP, ir. SECT. I. 40 TEU ELE2IENT8 OF TEE CHAP. II. SECT. I. Result. Subjects of inquiry regarding sensations. only sound, and so on. Yet when the object of sight or of any of the other senses is familiar to us, the one sensation which we can obtain by that sense calls up before our minds the ideas of a number of other sensations which we do not actually experience, but which we know we may experience if we fulfil the necessary conditions. These sensations, not actually experienced, but simply imagined, we may call ideal sensations. And so the result of our reflection upon the nature of the process of perception may be summed up thus : — In perception there is felt a sensation which is objectified or referred to some external object ; it also calls up ideal sensations of the other senses which are referred to the same object, and these ideal sensations are believed to be capable of realisation if the proper steps be taken : the object of perception is thus a collection of objectified sensations united into a whole and believed to exist in space. § 22. From this analysis of the process of per- ception and its object we may trace out a series of investigations regarding the different parts of the process. Sensations themselves are known to us only in consciousness ; they are mental phenomena. Our inquiries regarding them will have reference to their nature, their relations to one another, and to consciousness in which they are known. We must endeavour to learn also the nature and mode of their connection with the physical organism, the nature of the process which we have called objecti- P8YCE0L0GY OF COGNITION. 41 fication which plays such an iniportant part in per- ception, and the manner in which objectified sensations become united together in the object of perception. And since we have sensations suc- ceeding one another in time and objectified into space, the nature and origin of our ideas of time and space must occupy a prominent position in our investigations. Section II. ANALYSIS OF SENSATION. § 23. As we have seen that our perception of external objects may, by analysis, be reduced to organic sensations,* along with a conception of space, we must now give some attention to sensa- tions themselves. By sensations we mean those feelings or states of consciousness which, as we learn from physiology, are connected with certain nervous movements in our physical organism. Light, for example, is reflected from some external object and falls upon the retinae of our eyes. The minute fibrils of the optic nerve spread over the retina are sensitive to the light which falls upon them, and a nervous current of some kind is pro- pagated to the brain. The nervous action having taken place, the sensation of light or colour is felt. So there is reason to believe that all sensations are connected in a similar manner with certain bodily conditions. A fuller discussion of the circumstances * Sensations felt in consciousness but localised in the organism. CHAP. II. SECT. II. Sensations described. 42 THE ELEMENTS OF THE CHAP. II. SECT. II. Classifica- tion of sen- sations. of this connection will be attempted hereafter. But, in the meantime, it must be borne in mind that this reference to nervous activity as preceding sensation i^ no explanation whatever of sensation in itself, hut simply of the physical conditions upon which sensa- tion is felt in consciousness. A sensation can be known only in consciousness, and as sensations are the simplest mental facts which consciousness- affords, we cannot resolve them into any simpler elements, although it is possible that some complex sensations may be reducible to simpler ones. Our analysis of sensation will therefore be completed when we have — (1) arranged them into clearly- defined classes; (2) resolved complex sensations into their simpler elements as far as can be done ; and (3) determined how far this resolution can be effected, and especially if conscious sensations can be legitimately analysed into elements of which we are not conscious. § 24. Everyone is familiar with the five senses, or gateways of knowledge, as they have been called, by which we know the qualities of the external world. But, in addition to the sensations connected with these senses, it has been found necessary to form another class comprehending a variety of sensations clearly distinguished from the former. This class comprises all the sensations connected with the different parts of the organism with the exception of the five senses. This class and the sensations comprehended in it have been denominated variously, the vital sense, the organic PSYCHOLOGY OF COGNITION. 43 sense, the sensations of organic life, &c. A clear view of the great variety of sensations of which we are conscious may be obtained by the study of the following table : — '1. Connected with the bones, tendons, &c. 2, Connected with the nervous system. 3. Connected with circulation and nu- trition. 1 4. Connected with the general state of organs, as heat, &c. 5, Connected with the respiration. ^6. Connected with digestion. a. Smell. h. Taste. I. Of Organic Life. II. Of Intellectual Life. |l. rsranico-Intellectual. V 2. Intellectual. c. Touch. d. Hearing. e. Sight. I. From a glance at the parts of the organism referred to in this class, it will be readily apparent what sensations are indicated. The organs con- cerned in muscular exertion give rise to different sensations when in a state of repose, when active, when fatigued, and when resting after labour. The nervous system may suffer excitement or depression in various degrees or manners, and give rise to a variety of sensations. Hunger, thirst, and their opposites, with the sensations connected with them, depend upon certain states of nutrition and circula- tion. From a general condition of the body, which cannot be very clearly defined, there arise feelings of languor or the opposite, and also heat and cold ; the sensations of the latter kiod being, however, chiefly felt in the skin. The respiratory system is the seat of a class of sensations such as that of CHAP. ir. SECT. II. 44 TEE ELEMENTS OF THE CHAP. 11. SECT. II. Senses of smell and taste. suffocation, and there are sensations also connected with, the digestive organs. The general cha- racteristics of these sensations are that they arise in the organism itself as the concomitants of vital operations, and that they are accompaniments, results, or stimulants of action, not elements of knowledge, ^.e., of knowledge regarding extra- organic objects; but they are elements of our knowledge of the organism. II. The sensations of intellectual life are those whose chief end appears to be the imparting of knowledge regarding external things. 1. Two of these senses are so closely connected with the respiratory and digestive systems, and give us comparatively so little extra-organic knowledge, that their sensations occupy a middle position between those of the first class and those of the more intellectual senses which we have placed last in order. The sense of smell, placed at the portal of the respiratory organs, gives notice of the entrance of any noxious vapour into the lungs, and occasions the sensation of smell when any odorous emanations come into contact with the olfactory nerves. '*" The sense of taste is that by which we distinguish the sapid properties of bodies. The term, as 'commonly understood, includes much more than this ; being usually employed to desig- nate the whole of that knowledge of the qualities of a body (except such as is purely tactile) which we derive through the sensory apparatus situated within the mouth. But this is dependent upon the PSYCHOLOGY OF COGNITION. 45 assistance of the olf active sense, which, is affected by the odorous emanations of all such bodies as are capable of giving them off ; and the indications of which are so combined with those of the true gustative sense as to make an apparently single impression upon the sensorium. Moreover, there are certain sensorial impressions received through the organ of taste, which are so nearly allied in their character to those of touch, as to render it difficult to specify any fundamental difference be- tween them ; such are the pungent sensations pro- duced by mustard, pepper, the essential oils, &c., all of which substances, when applied for a suffi- cient length of time to any part of the cutaneous surface, produce a sensation which can scarcely be distinguished from that excited through the organs of taste, in any other way than by its inferior intensity, and by the absence of the concurrent odorous emanations. The taste of such substances might, therefore, perhaps be considered as the com- posite result of the impressions made upon the sensorium through a refined and acute touch, and by the effect of their odorous emanations upon the organ of smell/'* The sensations both of smell and taste may be arranged in a loose popular way into subordinate classes ; such as pungent, acrid, sweet, &c. But as no classification having any pretence to scientific accuracy and exhaustiveness has yet been offered, the subject does not demand much of our attention. * Carpenter, " Human Physiology," p. 177. CHAP. II. SECT. II. 46 TEB ELmiENTS OF THE CHAP. II. SECT. 11. Original distin- guished from ac- quired Icnoiuledge in sensa- tion. Sense of touch. It may be remarked by the way tiiat tbere are certain well-defined classes, inasmucli as the sensa- tions of one class, such as the bitter, cannot, by any means of which we are aware, be transformed into those of another. 2. We now come to the study of the sensations of the more intellectual of the special senses — touch, hearing, and sight. And it will be necessary to distinguish carefully between those which are pro- per and original to those senses and those which are acquired. We have seen already that in the case of two of these senses, hearing and sight, the sensation undergoes a process of objectification, being referred to a distance. In the case of touch this is not so obvious, although it is still true to a certain extent. The sensation of pressure, which is in itself purely organic, is referred to something not at a distance, it is true, but still external to the organism. Now, in each of these cases the objectifi.cation of the sensation, not being original, must be distinguished from the sensation itself. The sense of Touch has, as its proper organ, the skin, which " is peculiarly adapted for this purpose, not merely by the large amount of sensory nervous fibres which are distributed in its substance, but also by its possession of a papillary apparatus in which these nerves for the most part terminate, or rather commence." The tactual sensation proper is that which is felt when any body slightly comes into contact with the skin so as to make its presence felt. But this tactual sensation is often combined PSYCHOLOGY OF COGNITION. 47 and confounded with, otliers of a different kind. When, for example, the point of the finger is pressed against the table, in addition to the tactual sensa- tion, there is a feeling of resistance or hardness which is manifestly the sensation of muscular exer- tion objectified. Where the finger is rubbed over the surface of a rough, body there is also a combi- nation of the tactual sensation with that of muscular exertion. The skin is also the principal seat of the sensations of heat and cold, and when an object which differs in temperature from that of our body is brought into contact with it these sensations are experienced. But although the nerves of the tactual sensation are susceptible also to heat and cold, the two kinds of sensations are essentially unlike. From descriptions of the organ of hearing given by physiologists, we learn that it is a very delicate organ of touch. The object of hearing is sound; and the physical conditions of sound are vibrations of some material body which affect the air, and are propagated by it to the ear. The sensations of sound may vary in many ways, according to the nature of the sounds which are heard. The principal characteristics of single sounds are pitch or tone, clearness, volume or quantity. Two or more simultaneous sounds are harmonious or discordant. The pitch or tone of a sound is determined by the number of vibrations of the air which strike upon the ear in a second, and by many experiments this has been accurately determined. The other qualities CHAP. II. SECT. II. Sense of liearing. 48 TEE ELEMENTS OF TEE CHAP. II. SECT. II. Sense of sight. of sound appear to depend to a great extent upon the material and size of the vibrating body. The knowledge of the distance and direction of the body which causes the vibrations of the air is obtained by experience,* and the ability to detect slight differences between successive sounds and the harmony or discord of simultaneous ones is also to a certain extent an acquired power. We are con- cerned at present only with the sensations in their original simplicity which are marked by clear dif- ferences from those of every other sense, and discriminated from one another by many distinctions of pitch, strength, clearness, volume, and quality. The proper object of the sense of sight is light or colour; and the physical conditions of sensation are the emission or reflection of rays of light from some external body, and the transmission of these rays to the retina of the eye. Those who have studied the laws of light tell us that the colour of bodies depends upon the nature of their reflecting power. Some bodies, such as mirrors, reflect light without producing any change upon it ; others absorb and partly re-emit the light which falls upon them. Amongst this latter class, different bodies possess different powers of absorption and reflection ; and, in consequence of this difference, the white light which falls upon them is variously modified before reflection, and, falling upon the retina of the eye,, gives rise to the sensation of colour. " We all know * Of coarse we must postulate the possession of a suitable organism to render this experience possible. PSYCEOLOGY OF COGNITION. 49 that a ray of wliite light may be divided with a prism into several rays of different colours. It spreads out into a spectrum, in which the colours form a continuous scale. At the commencement of the scale is red, then come orange and the different yellows, then green, the different blues, indigo, and, lastly, violet, and each of these tints passes, by intermediate stages, into the one preceding it and the one following it. The science of optics shows us that the spectrum is formed by the different rays which make up the white ray being inflected, some more and some less, in passing through the prism ; this inflection increases with the shortness and rapidity of the waves ; therefore, if we follow, from red to violet, the series of rays which form the spectrum, we find the shortening and acceleration of the waves go on increasing. Thus from red to violet, each sensation corresponds to waves quicker and shorter than those of the preceding sensation, slower and longer than those of the succeeding sen- sation. An increase of speed and diminution of length in the waves are sufficient to determine the variations which our sensation of colour undergoes in passing from red to violet.''^ * § 25. The resolution of sensations into simpler elements is shown to be possible most clearly with reference to the senses of hearing and sight. In connection with the former, everyone is familiar with what we call a musical sound. That this sound is really a complex sensation is shown in several * Taine, '' Ou Intelligence/' p. 117. CHAP. II. SECT. II. Analysis of sensation. 50 THE ELEMENTS OF THE CHAP. ir. SECT. II. ways, and amongst others by experiments with the wheel of Savart. This wheel is a flat circular steel plate, having its circular edge cut to some depth into fine elastic teeth_, and made to revolve with great rapidity upon an axle. " When this wheel is turned at an uniform rate, its teeth_, which are at equal distances, strike a bar in passing ; and this regular succession of similar concussions excites a regular succession of similar sensations of sound. Now, while the wheel turns sufficiently slowly, the sensa- . tions, being discontinuous, are distinct, and each of them, being compound, is a sound. But when the wheel is set to turn fast enough, a new sensation arises, that of a musical note. It distinguishes itself from the remains of the noises which still go on and con- tinue distinct, and stands out as a fact of a different kind; among the different elementary sensations which make up each sound, there is one which the operation has separated ; and this now ceases to be distinct from the similar elementary sensation follow- ing in each of the succeeding sounds. All these similar sensations now combine in one long continuous sensation — their mutual limits are effaced ; experi- ence, just as in a chemical analysis, has extracted an elementary sensation from the complex group in which it was included, has joined it to an absolutely similar elementary sensation and formed a new com- pound — the sensation of musical sound.^^ * Thus it is seen that a particular sensation, that of a musical note, is capable of being resolved into more •=' Taine, " On Intelligence," p. 108. PSYCHOLOGY OF COGNITION. 51 elementary sensations, each of wliich is distinctly in consciousness. If we now examine a sensation of light, we shall see that it also is resolvable into more elementary sensations. The resolution of the sensa- tion is effected by the resolution of its most impor- tant condition, the ray of light. The prismatic spectrum comprehends a variety of distinct sensa^ tions which, previous to the analysis, must have been contained in the complex sensation of white light. A well-known optical toy, consisting of a disc of card- paper with the spectral colours painted upon it, made to revolve rapidly upon its axis, shows that the separate sensations may by rapidity of succession become blended together again and form one complex sensation more or less closely resembling the original one. The proper mixing of colours is an important part of the oil-painter's art, and in this there is a complex sensation produced by the mixing together in proper proportions of the oils, which, taken separately, would produce .? simple, or at least a less complex, sensation. We thus see that in many cases the sensations of the two most noble senses may be shown to be com- posed of more simple elements, being, however, still sensations. A similar course of investigation, regard- ing the sensations of taste, smell, and of organic life, would probably show that in all these cases there are many complex sensations which are capable of resolution. But it is needless to continue the inves- tigation farther, as we have already sufficiently esta- blished our conclusion, which may be thus stated : — CHAP. II. SECT. II. ^OfinS 52 THE ELEMENTS OF TEE CHAP. II. SECT. II. Result of Analysis. Analysis into un. conscious hut mental elements considered. (1). There are in consciousness sensations of a complex character, which, as far as consciousness is concerned, appear to be simple. (2). The resolution of these complex states of consciousness cannot be effected by consciousness alone, but by applying the methods of physical science to the physical conditions of these states of consciousness. (3). Hence, we may conclude the possibility of there being other complex states of consciousness, which, by mere reflection, cannot be analysed into their component elements. § 26. We now consider the possibility and legiti- macy of analysing sensations into elements which are not, and cannot, be brought within the sphere of consciousness.* Suppose that the point of a needle has been made so small, that when it is held in a clear light, di- rectly before the eye, it is just visible, and no more. Upon the principle of the infinite divisibility of matter, this point may be divided into two halves, each of which is invisible. Or, suppose that in the wheel of Savart, referred to above, all the teeth ex- cept two have been broken off, and the concussion of two teeth upon the bar is necessary to produce an audible sound. If one of these teeth be broken, the vibration of the remaining one will be inaudible. In * The doctrine of latent mental modification held by Sir W. Hamilton and others, asserts that underlying the sphere of our conscious activity there is a still more extensive sphere of mental activity, of which we are never conscious, but the results of which manifest themselves in consciousness. PSYCHOLOGY OF COGNITION. 53 both of these cases^ and in others which might be mentioned, a certain amount of physical antecedent is necessary as a condition of conscious sensation. And the question is. May that conscious sensation be resolved into mental elements of which we are not conscious ? By some it is held that this resolution is not only possible, but necessary to explain the phenomenon. Against this view the following objections may be urged : (1). The essential character of a sensation is that it is felt, and felt consciously. Therefore to analyse sensations into elements of which we cannot be conscious is not legitimate.* (2). There are other possible explanations of the difficulty. It may be that the object from which the light is reflected, or from which the vibration of the air proceeds, produces such a slight agitation of the intervening medium that it is spent or dispersed before it reaches the organ of sense. Or, suppose the agitation of the ether or air to reach the nerve of sense, it may be that the impression upon the nerve is so slight, that no vibration is propagated to the nerve centre in the brain, or that the vibration is so exceedingly slight as not to be a sufficient condition of sensation. And that either of these suppositions is the true one, appears to be supported by the fact, that certain artificial appliances, such * This objection, however, does not hold good against the possible latency of other forms of mental activity. There may be an activity of the ego which has no physical antecedent, and such activity may leave its trace not in the brain but in the spiritual nature beyond the sphere of consciousness. CHAP. II. SECT. II. Objections. 54 THE ELEMENTS OF THE CHAP. II. SECT. III. Revived sensations described. as the microscope, collect or intensify tlie physical conditions of sensation, so that what was before invisible or inaudible, may be distinctly seen or heard. The rays of light falling from a point invisible to the naked eye, are collected and con- densed by the microscope so as effectually to impress the optic nerve, from which we naturally conclude that previous to the use of the instrument the vibrations 'of the ether were so slight as not at all, or not sufficiently, to impress the nerve. It is possible, also, that there may be an excitement of nervous activity, either in the brain or the nervous fibres, but which is not a sufficient condition of sensation. In the meantime, we may conclude that the most probable reason why, in certain cases, a conscious sensation does not take place, is that the physical conditions, whether here or there, whether nervous or extra-organic, are inadequate. Section III. REPRESENTATION OF SENSATIONS. § 27. The possibility of the revival of a sensation once experienced is a fact familiar to everyone. But the sensation as revived is not the same as when actually experienced. It is idealised, it appears more refined, farther removed from sense than it was originally. Illustrations of this are numerous and familiar. If we have once seen a fine building PSYCHOLOGY OF COGNITION. 55 which, has made a great impression upon us by its architectural beauty^ a very slight effort will serve to recall before our minds its colours and outlines. We imagine that we almost see it. So of sounds. We are familiar with the voice of a friend ; in his absence it is quite easy to recall the tones and quality of his voice ; we fancy that we hear him speakiug. Other sensations of taste, smell and touch, are capable of revival in a similar manner, some more vividly, more approaching the original than others, but all to a greater or less extent. In all these cases the pheno- menon, the revived sensation, is recognised as related to the original one — a repetition of it, but different from it. Moreover, the sensation revived appears always to be connected with the same organ as when originally experienced. § 28. The physical condition of the revival of sensations is probably some agitation of the same nerves as served for the physical condition of the original sensation. The researches of physiologists, however, appear to lead to the conclusion that a particular part of the brain, the cerebral lobes, is de- signed to prolong and repeat the action of the nerves of the senses. And many philosophers, assuming that they know the functions of the different parts of the nervous system, have given minute elaborate explanations of the nervous motions which take place in correlation with the revival and varied combination of our sensations. A distinguished writer, who has made a great use of physiology in the explanation of psychical phenomena, has well CHAP. II. SECT. III. Fhysical condition of revival. 56 TEE ELEMENTS OF THE CHAP. 11. SECT. III. Correla- tion of ner- vous with psychical action in- directly in- ferred and not more than p7'o- lahle. expressed the indirectness and obscurity of our knowledge of the relation of nervous action to feeling in the following sentences : — (1.) ''Each individual is absolutely incapable of knowing any feelings but his own. That there exist other sensations and emotions, is a conclusion implying, in the first place, the reasoning through which he identifies certain objects as bodies of like naturewith his own body; and implying, in the second place, the further reasonings which convince him that along with the external actions of these bodies, there go internal states of consciousness like those accompanying such external actions of his own body. (2.) This conclusion, that there exist beings like him- self, and that under like conditions they experience like feelings, even supposing it entirely true (and it is not entirely true, for many facts unite to prove that, under like conditions, both the quantities and the qualities of sensations and emotions in different individuals differ considerably), by no means implies that what he knows under its subjective aspect as feeling is, under its objective aspect, nervous action. The average observer has not direct evidence that these other like beings have nervous systems, any more than that he himself has a nervous system, and he has no direct evidence in the one case any more than in the other, that nervous excitations are the causes of feelings. Experimental physiologists and pathologists only have proofs, and even their proofs are mostly indirect. The experiments which yield them are usually made on beings of another and PSYCHOLOGY OF COGNITION. S7 much inferior order. The contractions of muscles and arteries, caused by irritating nerve- trunks in frogs, the convulsive movements, and sometimes the sounds made by birds and mammals whose nerve centres are variously injured — these are the pheno- mena from which it is inferred that the human nervous system is the seat of the human feelings, and that these feelings are the correlations of its excitations. The only important verifications of the inference being those obtained during surgical opera- tions where nerve-trunks are cut through, and those furnished by post-mortem examinations of morbid nervous structures in the bodies of those who, when alive, displayed abnormal excesses or defects of feeling. (8.) And then, having learnt at second- hand, through the remotely inferential interpretation of verbal signs^ that in now one and now another of the bodies he recognises as like his own there has been found a nervous system, and that the stimula- tions of this produce those manifestations which, in himself, accompany feelings, the reader imagines a nervous system contained in his own body, and con- cludes that his sensations and emotions are due to the disturbances which the outer world sets up at its periphery and arouses by indirect processes in its centres."* Considering, then, the small number of facts bearing upon the question which physiologists have been able to observe, the indirectness of the ob- servations which have been made, and the obscure, infinitesimal character of the movements themselves, * Herbert Spencer's " El. of Psjch.," i., pp. 99-100. CHA.P. II. SECT. III. ss THE ELEMENTS OF THE CHAP. ir. SECT. III. Nature and rela- tions of idealised sensations. it appears impossible to determine with any degree of scientific accuracy the precise physical antecedents of those mental actions which are in a greater or less degree removed from sense. The attempts which have been made to do this are, and, from the nature of the case, can be, little more than conjectures founded upon uncertain analogies and few and crude observations. And although the facts which are known and admitted may warrant a general belief that the lower forms of mental activity, such as re- viving sensations, have special physical antecedents, yet there does not appear to be a suflScient ground- work of facts to justify us in constructing an elaborate and detailed theory regarding their correlation. Con- sciousness is the only direct and reliable revealer of mental facts, and although we may sometimes be assisted in our study of consciousness by the facts and observations of physiology, an attempt to make these the foundation of mental science is directly to reverse the natural order of things. Leaving out of account, then, the correlation, or inferred correlation, between physical and mental events, as only of secondary and occasional importance in the explica- tion of our subject, we proceed to the study of the revival and association of our sensations as revealed in consciousness. § 29. If a clear bright light be kept for a short time before the eye, and then removed, the sensation produced will persist for a time, and at intervals, per- haps, be revived. The same is the case with tastes, smells, and other sensations. But the sensation, as PSYCHOLOGY OF COGNITION. 59 persistent or revived, is not so clear and vivid as it was originally — it lias become idealised. The appear- ance before consciousness of idealised sensations is not fortuitous, but takes place in certain regular and connected series. Sensations of different quality, that is of different senses, are connected together, so that an actual sensation of one kind will serve to introduce, before consciousness, idealised sensations of other kinds. The sight of a particular kind of fruit with which we are acquainted, at once makes us think of its smell and taste. Thus, there are certain fixed groups of sensations which we regu- larly experience together, the different members of the group differing in quality. We have a com- plete knowledge of one of these groups, when we have once become conscious of all the sensations comprehended in it. And afterwards when any one of these sensations is actually felt, we know what the rest of the group are like. But it is not necessary that one of the original group should be actually felt in order that the whole may be ideally recalled. If a particular sign, as, for example, the word orange, have become attached to a certain group of sensations, the repetition of the sign will serve to recall the whole group quite as really as the consciousness of any one of the sensations of the group. Thus, a sign of a group of sensations be- comes by association, as it were, a part of the group, and our curiosity regarding a sensation is satisfied when we are able to refer it to a certain known group of sensations, and to attach to the CHAP. II. SECT. 111. 6o THE ELEMENTS OF TEE CHAP. II. SECT. III. Order of sensa- tions : successive. memory, group the sign by whicli it is usually designated. When a new sensation is experienced, our curiosity is excited because we do not know the other sensa- tions which are regularly connected with it, or the sign, or name, by which the whole is denoted. Thus our knowledge of a sensation resolves itself into a knowledge of its quality, and a knowledge of the position or relation which it holds amongst other actual or idealised sensations. § 30. There is a twofold order in which series or groups of sensations may appear in conscious- ness. They may be successive, or they may be simultaneous. In the meantime we give our atten- tion to the first of these orders. A single sensation of any kind may persist or may be revived. An actual or revived sensation may call up in succession a series of other revived sensations of different kinds which we distinctly recognise as having been at one time actual. This successive order of sensa- tions, or revived sensations, involves the conception of time, and is the only means whicli we have of determining time. When we experience one of a group of sensations with which we are well acquainted, we recognise it as something which we have felt before, and we give it a position more or less definite amongst other previously experienced sensations ; in other words, we remember it. Thus, memory, in this reference, is the ability to deter- mine the position of a sensation in a successive past series of sensations. But idealised sensations may be referred also to a future time, that is, to some PSYCHOLOGY OF COGNITION. 6l future succession of ideal sensation which we think likely to be realised, and this is what we call expec- tation. Thus with reference to this subject, memory and expectation consist in the ability to place an ideal sensation into that position in the series of successive sensations which, in the one case, we believe with certainty were actually experienced during a time past, and in the other, we expect with greater or less assurance will be experienced during some future time. § 31. We thus arrive at the conclusion that sensa- tions become so connected together in groups, that one of a group is capable of reviving before con- sciousness all the others. But although we may describe these sensations as being our mental phe- nomena, we cannot determine what particular sensations shall constitute particular groups. This is done for us by nature ; or, in other words, there is a natural grouping of sensations in which we can- not, as a rule, produce any essential change. By experience only can we come to know the con- stituent elements of a group, and by frequently experiencing naturally connected groups of sensa- tions, a subjective association such as we have described comes to be formed between them. The succession of sensations before consciousness gives us time. The positing of an ideal sensation in the midst of a group recognised as having had a past existence, or as likely to have a future existence, is memory or expectation. This mental process, it must be borne in mind, as referred to here, is sub- CHAP. II. SECT. III. and expec- tation. Indepen- dence of the order of sensations. 62 TEE ELEMENTS OF THE CHAP. II. SECT. IV. Meaning 0/ object. sidiary to the acquisition of presentative knowledge, as we shall presently see. In the meantime^ we are not supposed to know anything except sensations^ revived sensations, and the relations which they bear to one another in kind, in time, and as members of associated groups.* Section IV. SENSATIONS AS OBJECTS. § 32. We have hitherto been considering sensa- tions merely as differing from one another in kind, and as succeeding one another in time, but in our analysis of self-consciousness f we saw that they are necessarily looked upon as being objects related to and known by the subject, self. We must now examine them more carefully in their character as objects of consciousness, in order to see if anything is involved in them which will help us in the explication of the process of acquiring our presen- tative knowledge. And the very word ohjectj contra- distinguished as it is from suhject, appears to indicate an element in our sensations which may be of great * It is possible that there are some sensations which cannot be revived except as parts of a group ; and, perhaps, there are few which can be recalled by a merely mental effort without the aid of some associated circumstances. But nevertheless it seems allow- able for us, as we have done in this section, to treat sensations as revived, excluding the conditions and accompanying circumstances by the helps of which they usually appear before consciousness. t Sect. III. chap. i. PSYCHOLOGY OF COGNITION: 63 importance. It indicates tliat sensations are pos- sessed of an element /o?'ei^?i to tlie subject knowing; tliey are regarded as being not-self. There are besides,, other features of sensations which render more complete their character of objectivity. In- dividual sensations cannot be created or annihilated at pleasure. We may, it is true, interfere with the physical conditions of sensations ; we may shut our eyes, get out of the reach of perfumes, or close our ears. But as far as self- consciousness is concerned, the conditions of sensations being fulfilled, the conscious self cannot but be cognisant of the sensa- tions which appear. And not only is the existence of sensations beyond the control of self, but also the grouping of sensations. The particular taste, smell, colour, and tangible quality which we designate by the name orange cannot, as far as consciousness is concerned, be made to undergo any change. There are natural combinations of sensations, not produced by subjective association, but evidently governed by some objective law, over which the conscious subject has no control. Thus, when we consider either in- dividual sensations, or natural groups of sensations, as objects, we see that their objectivity arises not merely from being opposed to the subject in con- sciousness, but also from the laws of their existence. They are known as objects in contradistinction to the conscious subject ; but their character as objects is not complete till they are considered as having laws of existence and mutual relations of their own, determined for them independently of any subjective CHAP. II. SECT. IV. 64 TEE ELEMENTS OF TEE CHAP. II. SECT. IV. Relations of sensa- tion-oh- jects. Intuitive theory of extension. association. Henceforth, wlien we speak of objects of consciousness, there will be implied the foreign * elements which we have now indicated. § 33. We now come to a question of great impor- tance in psychology, and about which there is great diversity of opinion. The objects of consciousness, the sensations and revived sensations variously grouped together according to their own laws, have an existence in time — they succeed one another. But their order in time is twofold ; they may be succes- sive, or they may be contemporaneous. Several objects may at the same time appear in conscious- ness ; several sensations of different kinds may be experienced at the same moment. And the question is, — What is the relation in which these contemporaneous objects of consciousness stand to one another? The following are clearly dis- tinguished answers to this question : — (a.) The co-existence of sensations at the same point of time implies their mutual externality, and therefore involves the idea of extension or space. Several sensations, as of smell, taste, colour, sound, may exist altogether, and as they are distinguished from one another in kind, they must appear to be the one without the other. And this relation of mutual outness is the simplest form in which we perceive extension. According to this doctrine, extension or space is a form of our sensations as well * Of course by ohjects here we do not mean anything extra- organic; but sensations as possessed of the foreign-to-the-ego cha- racter which we have described. FSYCEOLOGY OF COGNITIOK. 65 as time, and equally original in reference to our knowledge. There is a slight modification^ or per- haps an integral part of this theory, in which it is held that some single sensations, as colour and touch, occupy space, or are diffused over an extended space. Whether the one or the other, or both of these opinions be held, it is manifest that their holders look upon space as an original form of sensation, and perceived intuitively in the same way as time.* (b.) In opposition to the above theory it is held that all mental phenomena are unextended, and that the possession of extension is the essential characteristic which distinguishes physical from mental objects. A sensation, therefore, as an object of consciousness, cannot possibly occupy extension or place. And ^ since an individual sensation does not exist in space, it is impossible that the relation between two or more contemporaneous sensations can be a spatial relation. To speak of the mutual externality of sensations is, therefore, to attribute to sensations a mode of ex- istence which they do not possess. Sensations differ in kind, and they succeed or co-exist with one another in time, and the attributing to them of any other relation would destroy their character as mental phenomena. § 34. Those who hold the second of the preceding views regarding sensation must in some way account for the origin of our conception of extension. Sensa- tions, the primary object of consciousness, are not themselves extended, but we evidently possess a * For a full exposition and defence of this theorj, see § 36. F CHAP. II. SECT. IV. Objection consti. tuting a general opposing theory. 66 THE ELEMENTS OF TEE CHAP. II. SECT. IV. A priori theory of extension. Muscle- and-tiirie- tlieory. notion of extension which we must have got in some way. How has it been attained ? The answers to this question divide themselves into two classes : — (a.) Some maintain that extension is an original principle of our constitution which springs into con- sciousness upon the occasion of some sensation taking place. The sensation, although not itself extended, suggests extension by a law of our nature. Exten- sion is thus an a priori but latent conception which rises up into consciousness upon the occasion of a certain experience, but is not the result of that ex- perience. Now, it is evident that the placing of any conception amongst d 'priori principles simply amounts to a confession of inability to explain it otherwise. Inexplicability is an important charac- teristic of all conceptions believed to be a priori. But before admitting any notion to be inexplicable, we are in duty bound to examine any attempt which has been made to explain it. The following attempt is the most important. (6.) It is held by J. S. Mill and others that the notion of extension is the product of muscular sensa- tions differing in intensity and duration. " Suppose," says Mr. Mill, "two small bodies, A and B, suffi- ciently near together to admit of their being touched simultaneously, one with the right hand, the other with the left, here are two tactual sensations which are simultaneous, just as a sensation of colour and one of odour might be ; and this makes us cognise the two objects of touch as both existing at once. The question then is, What have we in our minds PSYCSOLOGY OF COGNITION. 67 when we represent to ourselves the relation between these two objects, already known to be simultaneous, in the form of extension or intervening space — a relation which we do not suppose to exist between the colour and the odour ? Our answer to this is, *' That whatever the notion of extension may be, we acquire it by passing our hand or some other organ of touch in a longitudinal direction from A to B ; that this process, as far as we are conscious of it, consists of a series of varied muscular sensations. . . . When we say that there is a space between A and B, we mean that some amount of these muscular sensations must intervene ; and when we say that the space is greater or less, we mean that the series of sensation (amount of muscular effort being given) is longer or shorter. If another object, C, is farther off in the same line, we judge its distance to be greater, because to reach it, the series of muscular sensations must be further prolonged, or else there must be the increase of effort which corresponds to augmented velocity. Now this, which is unquestion- ably the mode in which we become aivare of ex- tension, is considered by the psychologists in question to he extension. The idea of extended body, they consider to be that of a variety of resisting points existing simultaneously, but which can be perceived by the same tactile organ only successively, at the end of a series of muscular sensations which con- stitutes their distance, and are said to be at different distances from one another because the series of intervening muscular sensations is longer in some F 2 CUAP. II. SECT. IV. 6S THE ELEMENTS OF TEE CHAP. II. SECT. IV. Refuted. cases than in others. . . . An intervening series of muscular sensations before the one object can be reached from the other, is the only peculiarity which (according to this theory) distinguishes simultaneity in space from the simultaneity which may exist between a taste and a colour, or a taste and a smell; and we have no reason for believing that space or extension in itself is anything different from that which we recognise it by.^' * Here then is an attempt to explain extension by one who does not think extension is involved either in single sensa- tions or in the relations of different but simultaneous sensations. Let us examine the attempt : 1. It is assumed that extension is identical with that by which it is recognised or measured, that is, with a succession of muscular sensations occupying time.t But this is by no means to be admitted. * " Mill Ex." pp. 273-275. t The Saturday Keviewer, commenting upon this sentence, says : " Such is not the assumption. We do not answer for Mill's expression of the theory at all points ; but the substance of it is, not that extension is the same thing as muscular sensa- tion, but that our notion of extension is an abstract mental symbol of possible muscular sensations, which is the result of in- numerable muscular sensations that have taken place in the actual experience of ourselves or our ancestors." We did not, assert that Mill's theory was " that extension is the same thing as muscular sensation." The sentence commented upon makes extension identical with a succession of muscular sensations occupying time ; and this is exactly Mr. Mill's expla- nation in brief. It is unfair to take a summarised statement of a theory as a subject of criticism when a more or less full and complete statement has been given ; and we submit that the full statement is probably as accurate an account of Mr. Mill's theory as could be given within our limits. Of course, the conception of FSYGROLOGY OF COGNITION. 69 The amount of force with wMcli a ball is expelled from the mouth of a cannon is recognised and measured loy its velocity, that is, by the number of feet which it traverses in a second of time. But no one ever maintains that force is identical with velocity. In the same way, although extension is measured by a succession of muscular sensations occupying time, to say that the former is identical with the latter is quite unwarranted. 2. Why is it that muscular sensations are chosen to fill up the intervening space between one point and another ? All sensations are ex hypothesi equally destitute of extension. The two points, A and B, are recognised by two sensations, and must be assumed not as points in space, but as points in time, because the idea of space is not supposed to be known. Let, then, the point A be marked by a particular sensation, say of smell; a number of intervening sensations, muscular sensations, or any others dif- fering in intensity and duration take place. Then another point of time, B, is reached, marked by extension, according to Mill, is an abstract mental symbol drawn from actual experiences of muscular sensations succeeding one another in time ; and we presume that the careful student would gather as much from our statement. Where Mr. Mill teaches that the actual experiences are either our own experiences, or the experiences of our ancestors, we do not know and would be glad to be informed. Some of Mill's successors in the same line of psychological thought have been driven to feel the weakness of his theory of the origin of our conception of extension, and have imported ancestral experiences in order to help it out of the dif- ficulty. It is illegitimate, however, for the critic to introduce this as an element in his criticism of our statement of Mill's theory, which we still maintain to be substantially correct. CHAP. II. SECT. IV. 70 THE ELEMENTS OF TEE CHAP. II. SECT. IV, another sensation. Thus, here we have two points, A and B, points in time, and recognised by two distinct sensations, separated from one another by a number of intervening sensations, say of sight, or hearing, or smell, differing in intensity and duration. Is the result of this an idea of extension or space? Certainly not. The mere statement of the problem substituting for '^ muscular sensations '^ any other kind of sensations is sufficient to show the ab- surdity of deducing the notion of extension from that of sensations succeeding one another in time. 3. The reason why muscular sensations are chosen to fill up the space between the points A and B, instead of sensations of smell, or taste, or colour, appears to be that the former kind of sensations is conjoined with mo ^^o?2', which involves extension, and the points A and B are tacitly assumed to be points in space. For let us eliminate carefully from the data all spatial elements, and see what follows. The sensations by which they are marked are at first supposed to be simultaneous. In this there is only time. But the idea of space is said to be acquired by passing the hand from A to B. Suppose the hand is at A. Here is a sensation in time. B as yet does not exist, because the existence of the point must not be assumed till the sensation indi- cating it has taken place. The hand leaves A ; the point A ceases to exist, except in memory, because the sensation indicating it has ceased. The hand reaches B ; a new sensation takes place, a new point in time has been reached. But where is A ? In PSYGEOLOGY OF GOGNITION. 71 memory. It is a point not now existing, except in past time. To speak, therefore, of two points of time existing simultaneously is altogether unmean- ing. And Mr. Mill's explanation is quite unintel- ligible unless the points are tacitly assumed to exist in s]pace and the muscular sensations to result in motion. Thus the very idea whose origin the theory professes to explain is quietly assumed at the begin- ning of the explanation.* § 35. The preceding theory of extension, called by Mr. Mill the psychological theory, being found untenable, we are driven back to a reconsideration of the view which makes the notion of extension an a priori principle of the mind. According to this theory, the mind possesses in its own structure, as it were, a notion of space, but not a conscious one, and upon a certain experience this notion becomes conscious and is projected upon the object of ex- perience. Now, with reference to this view, we confess, in the first place, a strong prejudice against the explanation of a difficulty by some latent or a "priori mental principle. It simply amounts to a confession that the difficulty cannot be explained, and moreover it assumes the existence of a mental * We do not know that anything would be gained by con- sidering sensations as possible of being repeated in serial order, and repeated as many times as we choose to fulfil the conditions of feeling the sensations. This would indeed give us the idea of some 'permanent object, independent of self, from which the pos- sibility of the sensations arose. But we do not see how repeated series of sensations, succeeding one another in time, could give us any idea of extension which could not be obtained from a single series of such sensations. CHAP. II. SECT. IV. A priori theory rejected. 72 TEE ELEMENTS OF THE CHAP. II. SECT. IV. Extension how first given. principle beyond the sphere of consciousness, which, is, in philosophy, a very questionable procedure. And still farther, our conception of extension is not that of a subjective principle, but rather of an objective condition of things. For these reasons we decline to accept the view in question, although probably there is a certain truth involved in it, and go back to a more careful consideration of the first answer to the question, '^What is the relation in which these contemporaneous objects of conscious- ness stand to one another ? " That answer was that " the co-existence of sensations at the same point of time implies their mutual externality; and therefore involves the presentation of extension." § 36. In considering this view it must be borne in mind that sensations are considered as objects of consciousness. They have been set over against the subject into the position of the non-ego ; they have laws of existence and mutual relations of their own. They are found collected together in groups or arranged in series, the different members of the groups or series not being capable, by any voluntary efforts of ours, of being separated from the other members. Thus they are recognised as having an element of foreignness-to-the-suhjed in them. The grouping of'these objectified sensations is infinitely varied. Sensations of touch, and sight, and hearing, and taste, and smell, and muscular effort, are all combined in wonderful variety ; and by the com- binations and variations of these sensations the infant mind, just beginning its experiences in a new PSYCHOLOGY OF COGNITION. 73 CHAP. II. SECT. IV. worldj becomes acquainted with, its organic sur- roundings. The little hands take hold of a toy, the eyes look at it, the mouth tastes it, the ears hear its rattle; in a great variety of ways these sensations are combined and modified. In the course of infinitely varied experience these sen- sations become localised in the midst of fixed groups of actual or ideal sensations. A sen- sation is localised when it becomes, in experi- ence, inseparably connected with a group of other sensations ; as, for example, when the taste of sweetness, in the mouth of an infant, is found connected with the peculiar feeling of a long cylindrical stick of candy, with the colours that are seen in it, and with the muscular sensations con- cerned in carrying it to and from the mouth, and so on. All these sensations become inseparably grouped together, that is, they become localised in an object, partly organic and partly extra-i ^X^^ S^ organic. Now it is to be observed that these ob4 jectified sensations appear in consciousness not merely in successive order as a temporal series; seve- ral of them appear simultaneously in consciousness ; they hold the same position in time, and they are also external in reference to one another. This externality is perceived immediately, an intuitive act of consciousness. We can be conscious of more than one object at the same moment of time, other- wise all comparison would be impossible. And in the early consciousness of objectified sensations several of them may be and are comprehended in L^/. :^r 74 TEE ELEMENTS OF THE CHAP. II. SECT. IV. the same act of consciousness. These sensations^ simultaneously intuited^ are not confounded with one another; they are clearly distinguished as being differenced the one from the other^ as the one being outside of the other, and the one differing in quality from the other. And this mutual ex- ternality of objectified localised sensations, as per- ceived in consciousness, is the first and essential element of the perception of extension. § 37. The preceding paragraph is concerned with the question, How are the essential elements of extension given in consciousness ? The answer to this question may be thus summarised: — First, sensations are objectified, set over against the knowing subject as being known- secondly, they are grouped together in a variety of combinations, and when any one sensation becomes -inseparably connected with a particular group it is said to be localised in that group ; thirdly, these groups of objectified and localised sensations may be either successive, in which case we perceive that they hold to one another a temporal relation ; or they may be simultaneous and distinguished from one another by difference in quality, in which case we perceive that they hold to one another a spatial relation. The first of these relations, the temporal, is admitted by all psychologists to be given in an original intuition of consciousness ; and we have here maintained that the second of these relations is given in the same way. It is to be understood of course that the process of abstraction must be employed before the PSYCHOLOGY OF COGNITION. 7S perceptions of sensations succeeding one another and sensations being mutually external to one another become developed into the conceptions of time and space. With this inquiry we are not at present concerned. There are two other subjects of investigation intimately connected with our subject, which must likewise be set aside for the present. The first of these has reference to the grouping and presentation of sensations in consciousness. How comes it that such and such sensations are presented in consciousness, that they are differenced from one another in such and such ways, that they are presented in such and such groups, that this appearing and disappearing depend upon such and such conditions ? This subject of investigation would take us into a sphere beyond that df psycho- logy proper, as it is concerned with the constitution, origin and laws of that most important element of the non-ego known as the organism. The second has reference to our ability to per- ceive sensations as succeeding one another in time and co-existing in space. How is it that the knowing subject can be conscious of its objects as coming the one after the other or as existing side by side in mutual wlthoutness? That this ability of the conscious subject is an ability not derived from the infinitely varied groups of sensations which appear in and disappear from consciousness, we feel certain ; that it implies a certain constitution and origin of the knowing subject different from the constitution and origin of the organism, we also CHAP. II. SECT. IV. 76 TEE ELEMENTS OF TEE CHAP. II. SECT.V. B4sum4. believe. But the determination of tlie mental consti- tution which, makes possible the perception of succes- sion and externality and the conception of time and space is also beyond the sphere of psychology, and would lead us into the profound depths of metaphysics, which are not the subject of the present treatise. We have now reached all the elements necessary to complete our knowledge of that nearest and most complex portion of the outer world, the organism. And it will be our endeavour, in the next section, to study that process of acquiring knowledge next in order, the perception of external objects. Section V. PEECEPTION. § 38. In our analysis of perception we saw that our knowledge of external things may be resolved into certain sensations of different kinds, supposed to be at a distance from us, and united together in objects. Perception thus consists of sensations projected into space, and united together in a per- manent group, supposed to have an existence independent of the mind which perceives. In the synthetical construction of our knowledge we have already studied sensations as objects to conscious- ness, and learned what is involved in them. We have already attained the knowledge of extension as the form of the non-ego immediately presented to consciousness ; and we have seen that this non-ego FSYCHOLOGY OF COGNITION. 77 constitutes that complicated physical organism by means of which more remote objects are brought to our knowledge. We have now to trace the educa- tion of this complicated sense, the process by which it enables us to perceive distant objecis and their qualities. § 39. The sensations which chiefly make known to us the existence of objects outside of our bodies are doubtless that of touch and the muscular sensa- tion. In the exercise of the muscles, portions of the body are brought into contact with some objects outside of them which excite sensations of touch and resist muscular effort. The sensations of touch and muscular effort appear to have one object^ and the resistance which it offers reveals its externality to the physical organ 'and independence of it. Thus there is produced within us the belief of the exist- ence of some object of touch without us ; and as that object opposes a greater or less amount of resistance to muscular pressure, we think of it as having a power to resist pressure, that is as being hard and solid. Thus hardness is the correlative of muscular force, the sensation of muscular exer- tion projected outside of our bodies and attributed to some external objects. But that which, in the organism, was a sensation, when thought of as with- out, is called a quality. Sensation and quality are thought of as having a twofold relation ; the one with reference to knowledge, the other with reference to existence. In the first reference, sensation is the sign which suggests to us the quality ; in the second, CHAP. II. SECT. V. Sensation and quality. 7^ THE ELEMENTS OF TEE CHAP. II. SECT. V. Projection of colours. the quality is thouglit of as the cause whicli produces the sensation. The muscular sensation is connected also with motion of the limbs of the body, and when this motion is combined with the tactual sensation there is made known to us the smoothness, rough- ness, or other superficial qualities of the bodies which we touch. And as a matter of course, the extension which we saw was involved in the diffusion or the mutual externality of localised sensations, accom- panies those sensations when projected outside of us. And thus we think of the hard or soft, rough or smooth objects of touch as being extended and figured. Hence we see that touch and its closely connected muscular sensations are very important means of augmenting our knowledge, carrying us away beyond ourselves into surrounding space and revealing a world of wonderful objects. But as far as we have gone, these objects are known to us only as correlatives of our tactual and muscular sensations invested with extension. We must now bring into requisition another sense, and see how the revelations of sight are combined with those of touch. § 40. It must be borne in mind that the know- ledge primarily given in sensations of sight has for its object Only a certain organic condition, and the colour which we see is really within us. , But it is equally certain that colours appear to be at a dis- tance from us, and consequently must have under- gone a process of projection out into space. And we are now to inquire how this process has taken PSYCHOLOGY OF COGNITION. 79 place^ or, in other words, liow the eye Las been educated. We have already seen that touch brings to our knowledge external resisting bodies ; and we shall see that this sense is the great educator of the eye, teaching it to clothe those bodies with the colours which appear in consciousness through the medium of the eye. It has been laid down as a law, " That a sensation appears to us to be situated at the spot in which we are accustomed to meet with its usual cause or condition, and this spot is the one at which tha explorations of touch are capable, by acting there, of checking or modifying the commenced sensation.^^ * A coloured object, for example, is placed within easy reach of a child^s hand. The colour is a sensation which the child has not yet learned to project beyond its own eyes. Its hand touches and partially covers the object; the sensation of colour is at the same moment inter- fered with and modified. Thus a sensation of touch, by repeated experiments of a similar kind, becomes intimately associated with sensations of colour. The principal organs of touch, the hands, are themselves objects of vision. By repeated and various com- biuations of tactual and visual sensations, the object of touch is believed to be the same as the object of sight. But the movements of the hands serve to measure distance, and as the visual sensations soon become inseparably associated with everything which the hands touch, these sensations are thus projected to a distance from the eye. The power * Taine "On Intelligence," p. 314. CHAP. II. SECT. V. By associ- ation with touch. 8o THE ELEMENTS OF THE CHAP. II. SECT. V. Other sen- sations as- sociated and pro- jected. of projection having been once acquired, the pro- cess by wbicli it was acquired is forgotten, and the eye spontaneously and unconsciously refers sub- jective sensations of colour to external and distant objects. The estimation of particular distances is soon acquired, depending upon clearness or ob- scurity of colour, number of intervening objects, magnitude, and other circumstances which will readily occur to any one. § 41. A connection between the object of touch and the object of hearing, and between the objects of hearing and the objects of sight, is formed by a process similar to that described in thelast paragraph. Hearing and sight are the only two senses in which sensations are projected to any considerable distance, and as the acquired powers of both are obtained chiefly through the assistance of touch, there is an intimate connection between all the three. A sensa- tion of sound having taken place, it is immediately transferred to a distance, and we attempt to conceive or perceive what the sounding object looks like. In other words we attempt to explain to our minds the object of hearing by translating it, as it were, into an object of sight. In the same way, a sensation of colour having taken place, we at once project it to a distance, greater or less according to circumstances, and then connect it with sensations of touch and muscular sensations, or think what it would feel like if we were within reach of it. Thus we explain and enlarge the knowledge communicated to us through one sense, by connecting it with or translating it PSYCHOLOGY OF COGNITION: 8l into tlie idealised sensations of tlie other senses. And tlie objects of the material world around us, as far as our knowledge of them is concerned, consist of various sensations projected to a distance without us, and united together in such a way that when one of them occurs, the others are invariably believed to be possible. But this objective union is not of our creation; it is manifestly a condition of the non-ego which we become aware of by the process we have indicated, but which we did not produce and cannot change. § 42. We are now led to a more careful considera- tion of this distant non-ego. As far as our knowledge of it is concerned we have seen that it consists of sen- sations projected into space and combined variously into different unities called objects. These pro- jected sensations we call qualities, and thus objects are composed of a number of qualities. But objects thus composed are manifestly the creation, to a great extent, of our own minds. The sensations are mental phenomena; the act of projection, and the combina- tion of sensations of touch with those of sight, and others, are mental processes. The foreignness and in- dependence of these objects to the mind are revealed only in the fact that the mind cannot create or annihilate its sensations at will, and that the laws of the combination of these sensations are evidently not mental laws, but laws of the non-ego. In the ohjectiveness of projected sensations and their laws there is believed to be involved the existence of some non-ego independent of our knowledge. A CHAP. II. SECT. V. Extra, organic objects. 82 THE ELEMENTS OF THE CHAP. II. SECT. V. Phenome- nal and noumenal elements. Quality ambirju- ous, sensation — for example, a colour — is something of which we are conscious, and even after the process of projection has taken place, after the eye has been educated, and we perceive the colour as at a distance from us, it is still a thing known to us. But besides this colour as known, we think of some cause or power existing beyond or behind the projected sen- sation which, striking upon our eye, has produced the sensation. This cause or power cannot be a sensation ; it is supposed to exist anterior to and independent of our sensation. It cannot be an object of knowledge, because it can be known only as a sensation ; but ex hypothesi, it has an existence anterior to sensation. Thus, the non-ego appears to consist of two elements; an element which is known, and an element which is unknown, but supposed to exist. The known element, we have seen, consists simply of projected sensations ; the unknown element is composed of something which, when brought into relation with our senses, helps to produce sensations. The term quality has unfortunately become am- biguous by being applied to both of these elements. When it is said that the quality of an object is one of its characters by which it is known to us, it is evidently a projected sensation, for all objects as known consist of such. When it is said that the quality of an object is that which produces a certain sensation in us, it is applied to something which, apart from the sensation, is unknown. The former of the two applications of the word quality appears to us the most natural, and by quality we shall. FSYCEOLOGY OF COGNITION. 83 therefore, hencefortli indicate those characteristics of objects which constitute our actual knowledge of them. There is^ however, a still farther restriction to the term quality, or at least an important dis- tinction between two kinds of qualities. The quali- ties of colour, smell, hardness, &c., are simply sen- sations of sight, smell, muscular effort, &c., ideally transferred or projected into external space. But the space into which these sensations are projected or which they occupy is not a sensation of any kind. Although in our knowledge it is inseparably con- nected with sensation, it is essentially different from sensation. To adopt scholastic distinctions, it is the form of which sensation is the mattery the quantity of which sensation is the quality. It is therefore perhaps improper to speak of extension, figure, and other forms of space as being qualities at all. They are rather the spatial relations of qualities, the ob- jective form into which sensations, being projected, are known as qualities. This essential distinction between the form of sensation and sensation itself has given rise to the distinction between primary and secondary qualities, the former comprising different modes of space, and the latter qualities properly so called, that is, projected sensations. Taking quality in the latter, that is in its proper sense, there is another distinction, although not an essential one, which may be observed. The mode of operation of the different senses is somewhat different. In touch there is necessarily a contact between the external object and the organism ; in sight, hearing, G 2 CHAP. II. SECT. y. Quality distin- guished from form or quan- tity. 84 THE ELEMENTS OF TEE CHAP. II. SECT. V. non-ego. and smell, the necessity of similar contact is not so obvious. Consequently touch has been supposed by some to bring us into contact with objects as they really exist; other senses not. Hence the distinction of some qualities being supposed to be more essen- tial to the idea of body than others, or of some being purely subjective while others are partly or wholly objective. Perhaps such distinctions have arisen also from the fact that in some of the senses— for example, sight and hearing — there is obviously a perception of distance, or a projection of the sensa- tion, while in others, as smell, there is not so much or so clearly so. Whatever may have given rise to such distinctions, they are fallacious. All qualities properly so called are originally sensations and subjective. All sensations come to be objectified, and involve elements belonging to the non-ego. All sensations except purely organic ones are pro- jected ideally beyond the organism and there known as qualities, while purely organic sensations, that is, sensations which are discovered not to depend upon extra-organic conditions, are not thought of as qualities at all. Consequently the only essential difference between qualities of objects arises from the difference between the hinds of sensations.* Other differences are either fallacious or accidental. § 43. Having considered the constituent elements of objects as known to us, that is, as consisting of real or ideal sensations projected into space and forming there a unity, let us now give some * For another distinction, see § 199. PSTCEOLOGY OF COGNITION. 85 attention to the supposed imJcnown non-ego. When we perceive a colour, we think of some unknown cause or power which, coming into contact with our eye, gives rise to the sensation. So every other quality of objects suggests to us the existence of something behind it and beyond it which, in relation to our organism, gives rise to different sensations. Whatever this is, it is and must be in itself un- known, because when it comes within the sphere of our knowledge it is already transformed into some sensation or other mode of consciousness, and when we attempt even to conceive it, it must be conceived under the form of some mode of consciousness. Let us, for clearness, call this unknown something x. There is then supposed to be an a? corresponding to every different quality which we perceive. And we may ask. What is the relation between the x of one quality and that of another ? Is the x of light, for example, or a particular colour, the same as the x of heat ? Is the x of smell the same as the x of taste ? Or is there only one x for all qualities, which coming into relation with our organism, gives rise to the different kinds of sensations of which we are conscious ? These are some of the questions which may be proposed in connection with this subject, and we refer to them here chiefly for the purpose of setting them aside. They are not questions which it is the business of the psychologist to answer. In so far as they can be answered, they belong to the sphere of experimental physics or of metaphysics : in so far as they are insoluble, they should be left CHAP. II. SECT. V. 86 THE ELEMENTS OF THE CHAP. II. SECT. V. Proper tneaning and object of percep- tion. alone altogetlier. As far as psycliology is concerned^ we are confined to tlie analysis and synthesis of our conscious knowledge; and in perception tlie object of our knowledge in the sensible world, that is, the world revealed to us through our senses. Out- side or behind this sensible world we cannot go, either in perception or in imagination.* The un- known X of sensible qualities is not only incapable of being perceived, but also as x of being conceived. As in psychology we are concerned only with what can be known, questions regarding the unknown are referred to only to point them, out as irrelevant. § 44. We are now in a position to understand clearly what we mean by the object of perception. From what we have seen, it is manifest that perception is the act only of educated senses. And those who identify perception with consciousness must mean by it something different from what is usually meant by the word. The object of perception must be at a greater or less distance from the sentient organism. Its existence is made manifest by a sensation of colour or some other. The sensation is, as we have seen, transferred outwards, in a particular direction and to some particular distance. We see the object. But sight gives us nothing but colour and figure ; these qualities are, however, connected in our minds, in consequence of past experiences with other qualities. And if we have before seen the object, we are able to predict what other sensa- * We may, however, as we shall afterwards see, hj inference. See §§ 198-200 and 207-9. PSYCHOLOGY OF COGNITION. 87 tions it is capable of giving rise to. We can say liow it will feel, smell, taste, &c., that is, we recog- nise the object, and give it a name. Thus percep- tion implies at least one actual sensation, and several other ideal ones connected with it; implies also a belief that these ideal sensations will become actual if the necessary physical conditions are fulfilled. Now the sensible world, in perception, is separated from the mind, although in the analysis of the pro- cess of perception we have seen that this separation is not a real one. The sensible world is partly the creation of the conscious mind; and in the study of psychology it must ever be borne in mind that the objects of that world combine in themselves both subjective and objective elements, partake both of the ego and the non-ego. In the study of the par- ticular sciences, however, such as optics, acoustics, mineralogy, botany, as well as in the ordinary affairs of life, it is quite legitimate, and, indeed, necessary, to bestow independent existence upon the objects of the senses. This is done for us naturally in the education which our senses receive. And the study of objec- tive science does not require us to leave the stand- point of practical life while the study of psychology does. Note on the Process of Perception. The process of perception described in the fore- going section is so important that, at the risk of CHAP. II. SECT. V. 88 TEE ELEMENTS OF TEE CHAP. II. SECT. V. Elements of ^perceip- tion. being charged with iteration, we subjoin a some- what fuller description of it than the above. The crude phenomena which appear in consciousness are Feelings related to one another in point of difference, resemblance, simultaneity ^ or succession. The most primitive act of thought consists in the intuition of one of these relations. And next in rank is the synthetic act by which objects or elements thus related are connected together into unity. These primitive acts of thought, carried on involuntarily, result in certain products which constitute the simple objects of common knowledge ; and we now propose to study these products. We consider first the perception of difference and simultaneity. We have already seen that there can be no cog- nition of simultaneous objects without a perception of difference. That which enables the child to distinguish between colours, and sounds, and tastes and smells, is a certain difference in the manner in which his senses are affected. But along with this difference of sensation there is a co-existence of them. Sensations differing from one another in quality are frequently experienced in regularly com- bined groups. A connection is thus formed between them, so that when one of the sensations is experi- enced the ofhers are expected. This combination of a real with expected sensations constitutes an object. The formation of natural objects is there- fore one of the most primitive products of thought. All objects of knowledge are composed of a certain uniform group of sensations and expected PSYCHOLOGY OF COGNITION. 89 sensations ; but it takes a considerable amount of experience to determine accurately the exact con- stituents of objects. A child, for example, has been accustomed to take some disagreeable medicme from a spoon ; this experience has been repeated so frequently that a firm connection has been formed between the appearance of the spoon in the hand of the nurse and the disagreeable taste of the medicine. To the mind of the child, the hand of the nurse holding the spoon and the expected taste constitute an object ; and the child's mistake is corrected only when some pleasant food is given to it by the spoon. Then it learns that the taste of the medicine is not an invariable element of that cluster of sensations introduced by the sight of the spoon. The most important of the sensations connected together in the formation of objects are those of sight and touch. The sense of sight gives only colours differing from one another in quality and occupying a certain bounded space. The sense of touch combined with the muscular sense of effort leads to the inference of hard or soft, rough or smooth, resisting bodies existing outside of us. The motion of our limbs in contact with external bodies gives us the idea of distance ; but it takes a con- siderable time for the child to connect the figured colour which it sees with the resisting body which it touches. The same sensations of colour and the same sensations of touch and muscular effort having been frequently experienced together, the child learns to beheve that the object which it sees is the CHAP. II. SECT. V. Connec- tion of the objects of sight and touch. 90 TEE ELEMENTS OF THE CHAP. II. SECT. V. Distance — how measured. same as the object which, it touches. Other sensa- tions, as of smell, taste, or sound, are soon added to the group, and thus is produced the full concep- tion of a natural object. The distance of an object from the body is first measured by the motion of the hand towards it. The greater time and effort required to reacli an o jject the farther it is believed to be away from us. Bat it is observed also that the greater time and effort taken by the hand to reach an object, the diuimer does the colour of the object appear to the eye ; and the difference between clearness of colour- ing is still more observable when the process of walJcing is combined with the stretch of the arm. Ouher differences of appearance also are observed by the eye, as a greater or less size, a greater or less clearness in the appearance of the minute parts of objects and so on. These differences of appear- ance become gradually connected with the longer or shorter time and the greater or less effort required to reach objects with the hand, and thus we learn to see the distance of objects, or, properly speaking, to infer from visible appear- ances, what are the distances from us of the objects of touch. Hence we see that the perception of the objects of 'the external world is a combination of intuition and inference. We perceive intuitively actual sensations; we expect, by an involuntary inference, the other sensations of the group. We intuite sensations of muscular resistance; we infer some resisting external object. We intuite par- PSYCHOLOGY OF COGNITION. 91 ticular sensations of colour; we infer the distance to be passed over before particular sensations of touch can be readied. The products of thought just described are founded mainly but not exclusively upon the relations of difference and simultaneity ; other products of a primitive kind are founded mainly but not ex- clusively upon the relations of resemblance and succession. The child is conscious of the same sensation or the same group of sensations at succes- sive times ; the regular recurrence of the group of sensations leads to a belief in the identity of the object. Thus our belief in the permanence and independence of natural objects is the result of seeing that a present group of sensations resembles a group of sensations which we remember to have experienced some time ago. This recognition of similarity between present experienced sensations and past represented sensations is of the greatest importance as it is the foundation of our belief not only in the permanence of objects but also in the permanence and identity of ourselves. We have in this also the only means we possess of comparing all kinds of relations as well as objects with one another. Past periods of time, figures and dimen- sions of space, forthputtings of energy, experiences of pleasure and pain, are recalled and compared with present experiences ; and thus our lives are enriched by being able to bring together the past and the present. When the present group of sensations does not CHAP. II. SECT. V. Perma- nence of objects — how learned. 92 THE ELEMENTS OF THE CHAP. II. SECT. V. exactly resemble the representation of a past group, we get the idea of sameness of kind but difference of individual object. The child at first is unable to distinguish between its mother and other ladies ; but, soon differences are recognised and individuals distinguished. The ability to perceive minute differences in the midst of a general resemblance is necessary in order to enable us to distinguish one object from another ; as the ability to assert with confidence the exact resemblance of a present object and a representation is necessary to enable us to identify an individual. The uniform connection between succeeding events constitutes what we know of the causal relation. When a certain phenomenon is uniformly followed by another phenomenon, the two become so connected that when the one appears the other is expected. Uniformity of succession is thus an essential, though not the only essential element in the causal relation. We thus see that the objects and relations of our common knowledge are produced by the exercise of involuntary and to a great extent unconscious thought. When we first waken up to conscious life we find ourselves in the midst of a world of objects regarding which we know a good deal. This primitive knowledge is the result, no doubt, of an almost unconscious process which has gone on during the dreaming sleep of infancy, as our bodies and minds were being gradually adapted to our surroundings. PSYCHOLOGY OF COGNITION. 93 CHAPTER III. THEORIES OF PEBCEPTION. Section I. GENERAL DESCKIPTION AND CLASSIFICATION. § 45. In order to have a clear understanding of any theory of perception, it is necessary to compare it with and distinguish it from other theories from which it to a greater or less extent may differ. And in this chapter we purpose to bring together, for the purpose of comparison, the most important theories regarding this subject which have been held by philosophers. In the early history of philosophy, the different departments of study were not clearly distinguished from one another. In the writings of the Grecian philosophers, there were frequently collected together, in a confused manner, discussions on psychological, cosmological, theological, ethical and logical questions ; and a greater or less confu- sion of subjects that ought to be separately ex- amined may be found throughout the whole history of philosophy. It is natural that in the early stages of human knowledge there should be this confusion; but it is necessary to the progress of knowledge that this confusion should be cleared away. It is chiefly CHAP. III. SECT. I. Subject in- troduced. J 94 TEE ELEMENTS OF THE CHAP. III. SECT. I. Twopoints of view. in modern times, and especially since the time of Descartes^ that we find the original chaos of human knowledge becoming separated into clearly defined sciences. We shall therefore look for the theories of perception which we wish to examine only in the history of modern philosophy, from the time of Descartes, as in that period we are likely to find the clearest statements of the results of investigation into the nature of our knowledge of external things. Before proceeding to examine any of the parti- cular theories which have been held regarding per- ception, we purpose to take a general view of certain fundamental differences between these theories, by means of which we may arrange them into classes. The possibility of making a classification assumes, of course, a knowledge more or less complete of the things to be classified, and the reader must there- fore take for granted the accuracy of our general descriptions until he is able to verify them by the study of the special theories to which they may be applied. § 46. There are two distinct points of view from which the student of the process of perception may proceed in the examination of his knowledge. It is difiicult to find any single unambiguous word which indicates these points of view respectively, and therefore, without in the meantime naming them, we shall proceed to describe them at length. (1) From the first stand-point the psychologist regards the objects of the world of sense as having an existence independent of the mind, and the PSYCHOLOGY OF COGNITION. 95 phenomena of the mind as having an existence inde- pendent of material objects. The trees and stones and other objects which we know, and as we know them_, exist away outside of us, and the mind which knows exists somewhere within the body; and these two things, the external material bodies and the mindj are totally different in nature and indepen- dent in existence. And the problem of psychology is to determine how it is that the mind knows the objects of the material world, and what amount of confidence is to be placed in this knowledge. This is what we might call the stand-point of practical common sense. The practical man, with his sensive organism completely matured and educated, sees ob- jects in the world around him apparently existing independently of his mind ; and when he becomes a philosopher his great question naturally is how these objects which are extended, figured, and distant can be perceived by his mind, which is an unextended spiritual substance. Thus there is assumed the existence of two worlds differing in nature and independent in existence, and then the question is asked how does the one come to know the other, how does mind know matter ? For the sake of distinctness, and for want of a better name, we may call this the stand-point of practical dualism. (2.) Those who adopt th.e second point of view assume nothing regarding the existence or nature of an external world, but analyse all their know- ledge into its original elements as found in con- CHAP. III. SECT. I. Practical dualism. 96 THE ELEMENTS OF TEE CHAP. III. SECT. I. Philoso- phical stand- point. Origin of represen- tationism. sciousness, and beginning with the simplest facts given in consciousness, seek to discover the manner in which the sphere of our knowledge and belief is gradually filled up. As a preliminary to the adop- tion of this method it is necessary that nearly all our naturally acquired beliefs regarding the exist- ence and nature of objects of sense should, for the time, be given up. The object of the psychologist is to determine the origin and process of the acqui- sition of knowledge, and therefore it is not legiti- mate to assume anything regarding the existence and nature of the objects of knowledge until it is seen how they have become objects. From this, which we may call the philosophical point of view, the student works his way from within outwards, beginning with those facts of consciousness, which, as far as he can discover, are elementary, endeavour- ing to discover what they reveal of the non-ego, and how they are combined or modified, and in no case assuming anything which they do not give. One or other of these points of departure has been adopted and adhered to with greater or less consistency by nearly all modern philosophers. We shall not at present express any opinion as to their respective merits, but proceed to examine the theories of perception which may be classed under them respectively. § 47. We have said that the problem which the psychologists who adopt the first method require to solve is to determine how two independently existing and heterogeneous substances can have communi- PSYCHOLOGY OF COGNITION. 97 cation, the one with the other. Given that there exists a mind, spiritual and unextended ; that out- side in space there exist material bodies possessing various qualities ; how does the former come to know or believe in the latter ? The answers to this question have been various, and at present we shall not attempt any exact classification of them, as, indeed, perhaps no classification could be made without in some way doing violence to the theories concerned. Generally speaking it has been held that mind can have no immediate knowledge of matter, and that knowledge can only be effected by the intermediation of some image or idea which either represents or suggests the external object. The fundamental principle which appears to under- lie most of the theories of this kind is that the mind cannot directly know anything but its own ideas, and consequently these theories have been classed together under such names as idealism, representative idealism, cosmothetic idealism, &c. But it is to be borne in mind that injustice may easily be done to theories by forcing them into some particular classification because some common form of language is employed in them, without care- ful consideration of the real meaning of the language and of other essential principles which the theories conprehend. § 48. Amongst those who study the process of perception from the second, which we called the philosophical stand-point, there are important differences. They all begin by giving up the posi- CHAP. III. SECT. I. Philoso- phical method. 98 THE ELEMENTS OF THE CHAP. III. SECT. I. tion of practical dualism whicli is tlie result of the ordinary education of tlie organism tlirougli which, everyone passes. They analyse the objects of the senses into materials given in consciousness, and endeavour to ascertain those facts of consciousness which are irreducible to others more simple. Taking up their position thus at the origin of knowledge, they work their way outwards, tracing the process by which knowledge is gradually acquired. The principal differences which exist between different theories of this class arise from the different views which are taken regarding the nature and signi- ficance of the facts revealed in consciousness. As in the previous class we hesitated to attempt giving a more minute classification of the theories contained in it for fear of doing injustice to some of them, so now it will be as well to postpone minuter descrip- tion until we have examined the important theories which assume this stand-point. Our general division of theories of perception into two great classes has been instituted chiefly for the purpose of furnishing a sort of key to the understanding of the theories to be passed in review. We shall not examine all the theories of each class in immediate succession, but shall rather take them in the historical order of their appearance, being thus better able to perceive their relations to one another. PSYCHOLOGY OF COGNITION. 99 Section II. DESCARTES. § 49. Descartes began his pHlosopliising by resolving to doubt tbe truth of all propositions received at second-hand. He found himself able to doubt the existence of the world, of God, of his own body, of everything in short except doubt itself. But doubt is only a form, of thought, and hence, according to Descartes, the act of thinking itself, as given in consciousness, was the one certain founda- tion of all knowledge. But the assertion of thinking involves the assertion of a thinking being; cogito ergo sum. Thinking, in its widest sense, is the essence of mind. Having thus established a firm foundation on which to build the superstructure of his system, Descartes proceeded to prove the existence of God. According to him, ^'^ When the mind reviews the different ideas that are in it, it discovers what is by far the chief among them — that of a Being omni- scient, all-powerful, and absolutely perfect ; and it observes that in this idea there is contained not only possible and contingent existence, as in the ideas of all other things which it clearly perceives, but existence, absolutely necessary and eternal, .... so from its perceiving necessary and eternal existence to be comprised in the idea which it has H 2 CHAP. III. SECT. II. Descartes^ founda- tion. Proof of a Deity. ICX) THE ELEMENTS OF THE CHAP. III. SECT. II. Psycho, logy of per- ception. of an all-perfect Being, it ouglit manifestly to con- clude that this all-perfect Being exists." * We need not stop to criticise this demonstration of God's existence. To Descartes' mind it was satisfactory, and he employed his belief in God's existence and veracity as a part of his psychology of perception. He reasons thus : " It cannot be doubted that every perception we have comes to us from, some ^bj^ct different from ourjnind; for it is not in our power to cause ourselves to experience one perception rather than another, the perception being entirely dependent on the object which affects our senses. It may, indeed, be matter of inquiry whether that object be God, or something different from God; but because we perceive, or rather, stimulated by sense, clearly and distinctly apprehend^ certain matter extended in length, breadth, and thickness, the various parts of which have different figures and motions, and give rise to the sensations we have of colours, smells, pain, . &c., God would, without question, deserve to be regarded as a deceiver, if he directly and of himself presented to our mind the idea of this extended matter, or merely caused it to be presented to us by some object which possessed neither extension, figure, nor motion. For- we clearly conceive this matter as entirely distinct from God and from ourselves or our mind ; and appeareyen clearly to discern that the idea of it is fqi-med in us on occasion, of objects existi ng out of our minds, to which it is in every * "Principles," part i., si v. PSYCHOLOGY OF COGNITION. lOI respect similar. But since God cannot deceive us_, for this is repugnant to His nature, as lias been already remarked, we must unhesitatingly conclude that there exists a certain object, extended in lengthy breadth, and thickness, and possessing all those properties which we clearly apprehend to belong to what is extended. And this extended substance is what we call body or matter."" * § 50. From these extracts, and from other parts of his writings which need not be cited, we may draw out what appear to be the essential principles of Descartes' psychology. (a). He begins his investigations by starting from what we have called the philosophical stand- point, assuming nothing but the existence of think- ing as his foundation. Then from the nature of certain ideas which constitute his conscious think- ing, he infers the existence of an all-perfect and veracious Being. (6). Consciousness reveals to us also certain other ideas which are — (1) beyond our power to create or annihilate ; (2) ideas of extended substance giving rise to certain sensations ; and (3) occasioned by objects different from God ajid existing outside of our minds wMch they (the ide&fi)^7:£present . (c). These ideas being beyond_jDjir_._CLsni._powQr must be produced in us by„Sad. But since we clearly apprehend the idea of extended substance, and since God would not deceive us, it follows that this ext_ejided-sttbstance must exist outside of us. * "Principles," part ii., i. "^ CHAP. Ill, SECT. II. Systematic statement of Des- cartes' doc- trines. 102 TEE ELEMENTS OF THE CHAP. III. SECT. II. Criticism. [d). As the essential quality of mind is thiiiking, so the essential quality of material objects is exten- sion; other qualities^ such as hardness^ colour, &c.^ being variable, and therefore accidental. § 51. It is admitted that the point of departure of Descartes^ psychology is the true one ; and it is more than could be expected that his subsequent investigations as to the essential elements of our knowledge and belief should, at the beginning of the history of modern philosophy, be faultless « Consequently we find in the principles which he endeavoured to establish several weak points which afterwards produced evil results. To these we shall turn our attention. (a). The demonstration which Descartes gives of the existence of God assumes that whatever we clearly and distinctly conceive to exist must therefore have an objective existence. The nature of our subjective concept of God is the datum from which is inferred His objective existence. We believe in God^s exist- ence, therefore, because we trust that our faculty of conception will not deceive us. . We need not criticise this so-called demonstration, as that would be apart from our subject, but it will be necessary for us to remember that, with Descartes, the exist- ence of God depends upon the fidelity with which his own conceptions of God correspond to the ob- jective reality. And of fidelity, the only test which he is able to apply is the clearness and distinctness of the conceptions themselves. (fe) . There is great confusion in Dgscartes'_descrip- PSYCHOLOGY OF COGNITION. 103 ■ tion of tlie ideas of material objects. From tlie fact that thej are beyond bis power to create or annihilate^ he very rightly concludes that__they belong in some way to the non-ego. Bat when he speaks of ideas of extended substance, confusion is apparent. The idea^ if mental^ must^ according to Descartes^ principles, be unextended ; how then can it be "in every respect similar ^^ to that which is extended ? And again, when he speaks of ideas being occasioned by objects outside of us, he very evidently passes away from the philosophical stand- point to that of practical dualism. Objects are believed in only by inference from the ideas ; and it is illegitimate ^r5^ to assert the existence of objects as an inference from ideas, and then to shift one's ground and account for the existence of ideas by the presence of objects. It is equally illegitimate ] to affirm that the ideas represent or resemble the objects. In order to say that one thing resembles another we must have an independent knowledge of both, and then, having compared them, we can affirm their likeness or unlikeness. But ex hypothesi we have no independent knowledge of objects, no knowledge whatever of them except through their ideas. Hence we cannot assert that the one re- sembles the other. (c) . It is, according to Descartes, by the power of God that the idea of extended substance is produced in our minds, and since we have confidence in God's veracity, we believe that there is really extended substance without us. But the existence of God CHAP. III. SECT. II. 104 THE ELEMENTS OF THE CHAP. III. SECT. II. depends upon tlie clearness and distinctness of our ideas ; our idea of extended substance is also clear and distinct. It is difficult, therefore, to see why the inference from the clearness and distinctness of one set of ideas should be made use of to establish the inference which may be drawn with equal certainty from the clearness and distinctness of another set of ideas. Still farther, it is an un- warranted assumption, that our ideas of material bodies are produced in our minds by the power of God. Of course, in one sense everything is done by the power of God ; but, 5^ Descartes makes use of the power of God in his psychology, he means by.it some~ special interposition by which an extended substance may be represented to a mind which is unextended. The introduction of the power of God is, at best, an unphilosophical hypothesis for ex- plaining what, to the mind of Descartes, was an otherwise inexplicable difficulty. We shall see that this feature of Cartesianism afterwards became still more prominent. In consequence of Descartes' doctrine of divine interposition, it was unnecessary for him to endow matter with any active powers. And consequently he makes bare extension the one essential quality of material substance. As for other ideas, such as colour, hardness, taste, etc., they proceed from this extended substance, or rather result from the close and intimate union between the mind and extended substance. We do not at present criticise Descartes' doctrine that simple extension, instead of some PSYCHOLOGY OF COGNITION. 105 dynamical principle, is tlie only essential quality of tlie objective world. We call attention to it now in consequence of the influence wliicli it exerted upon subsequent speculation. § 52. The most important of the followers of Descartes was Malebranche (1638-1715). The doc- trine by which he is best known is only a further development of a principle belonging to Cartesiauism. Mind and body are two absolutely distinct and heterogeneous entities, and it is absolutely impossible that there can be any natural connection between them. Consequently Descartes said that our ideas of material bodies must really be produced by Grod. In the researches of Malebranche, this feature of Car- tesiauism is brought out into still greater prominence. He teaches that we, as spirits, exist in a manner in God, who is the place of spirits, and, participating in His knowledge, " we see all things in God." As God is omniscient, the ideas of all things in the universe must be in His mind ; and since we, as spirits, are also in Him, we perceive the divine ideas of material bodies. It is interesting and amusing to see what wonderful contrivances are invented to overcome the difficulty assumed to exist, that the mind, because un extended, cannot directly perceive extended body. And it is probable that most readers in modern times will regard the explanation as still more in- comprehensible than the original difficulty to be explained. Waiving, therefore, any general criti- cism of the doctrine as unnecessary, we shall point out a certain characteristic of the ideas CHAP. III. SECT. II. Male- hranche. io6 THE ELEMENTS OF THE CHAP. III. SECT. II. Cartesian meaning of idea. O"' y of Descartes and Malebranclie whicb. must be noticed. § 53. Both, of tliese pHlosopliers use the word idea to indicate some object of thought which, is dis- tinct from the activity of the mind in perceiving or thinking it, and which appears to have attributed to it an independent existence. For example, Descartes says :* " Further, I cannot doubt but that there is in me a certain passive faculty of perception, that is,, of receiving and tahing knowledge of the ideas of sen- sible things j but this would be useless to me if there did not also exist in me, or in some other thing, another active faculty capable of forming and pro- ducing those ideas.'' And he soon concludes that the active power of producing these ideas is in corporeal objectsL. "' ~— The cardinal doctrine of Malebrancbe's psycho- logy is that ideas of material objects can be directly perceived only by the mind of God; but since we exist in Him, we participate in His knowledge and perceive His ideas. Thus, in Cartesianism the idea is a distinct entity, contained in some mind either Divine or human, and existing quite independently of the mental activity involved in the perception of it. But a careful analysis of consciousness might have led these philosophers to the conclusion that the distinction between th.e act of thinking andthat which is thought, the act of perceiving and the percept, the act of conceiving and the concept, is only a logical one. Any conscious activity of the kind is on one side an * Med. vi. PSYCHOLOGY OF COGNITION. 107 act, on the other side an object or idea ; the act is the idea, the idea is the act, but viewed in another relation. The greatest confusion in psychology has risen from the use in different senses and for different purposes of the word idea. And it is necessary now either to banish the word altogether from use, or to employ it in a clearly defined meaning. In the meantime it should be noted that all mental phenomena are objects of consciousness, and cannot exist apart from the conV sciousness in which they are apprehended. And to speak of ideas as if they could pass from objects to the mind, or as if o^e mind could be conscious of the ideas of another,'' is either an abuse of language or the illegitimate attribution of independent exist- ence to an abstraction. Th is error of Cartesianis m long continued to cause confusion in psychology, but it is now long since it was perceived and abandoned. § 54. The philosophy of Spinoza (1632-1677) was, in a sense, the result of Cartesianism. The chief differences between the doctrines of Spinoza and Descartes had reference not to the psycho- logical process of knowledge, with which only we are now concerned, but to the nature of the real existence which underlies all phenomena. Desca rtes had postulated, the, exi stence j )f two substances, thoughJL^^tnd^ extens ion, as the necessary constitu- ents of, mind and_ matter^ But it~app eared to Spinoza that thought and extension are both them- selves phenomena, and cannot therefore be the suhstances in which other phenomena inhere. > ■> CHAP. III. SECT. II. Sjpinoza. io8 THE ELEMENTS OF TEE CHAP. III. SECT. II. Descartes' psycliological analysis had discovered only those attributes which, were found to be essen- tial to the mind and material body respectively. But Spinoza thought that all attributes must have a substance in which they inhere. And rejectiDg the dualism which had hitherto prevailed, he asserted that thought and extension are attributes of OTi^co^moru-substajQce which underlies them hoiL There is thus only one substance, self- existent, infinite and eternal ; and that substance is Gpd^ The qualities, however, of mind and matter are phenomenally distinct, so that, as in Descartes, there can be no direct causal or cognitive relation between them. But both are phenomena of one substance ; there is a correspondence between them. The thought corresponds to the thing ; the idea to the object. To enter into any detailed examination of Spinoza's pantheistic ontology would take us alto- gether aside from our subject. The only important correction which he made in the Cartesian psycho- logy was the assertion that thought and extension, being only essential attributes, cannot be considered as substances. We shall now leave Descartes and his followers for the present, and give our attention to the beginning of another philosophical movement in England. \< PSYCEOLOGT OF COGNITION 109 Section III. Locke. § 55. Locke, in his psycliology, begins with the principle, that there is nothing in the mind except what comes into it from without : it is like a sheet of white paper upon which experience writes our ideas. The experience which gives us . our ideas is of_two kinds, sensation and reflection : by the former, we perceive the qualities of bodies ; by the latter, the ideas we have derived from sense are variously modified, repeated, or combined. Our ideas are thus either simple or complex. " 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 understanding destroy those that are there.''* There are some ideas, such as those of colours or sounds, which gain admittance to the mind through one sense specially adapted for them. There are other ideas, such as of space or extension, which con- vey themselves into the. mind by more senses than one ; whatever the mind perceives in itself, or is the immediate object of perception, thought, or under- standing, Locke calls idea ; and the power to produce * Essav, bk. ii., cli. ii., § 2. CHAP. III. SECT. III. Lockers Ijrincijple no TEE ELEMENTS OF TEE CHAP. III. SECT. III. Primary qualities. Secondary qualities. LocTce's doctrines hriefiy stated. any idea in the mind lie calls quality of tlie subject wherein that power is. Qualities are of two kinds : First, those which are utterly inseparable from the conception of body, such as solidity, extension, j&gure, &c. ; and second, those which are nothing in the objects themselves, but powers to produce various sensations in us by their primary qualities. Bodies produce ideas in us ; in the case of primary qualities, by impulse, and in the case of secondary qualities, by the operation of insensible particles on our senses. The ideas of primary qualities of bodies are resemblances of them, and their patterns do really exist in the bodies themselves; but the ideas produced in us by the secondary qualities, have no resemblance of them at all. Perception is the first and simplest idea we have from reflection upqn_aegsations. Before perception can take place there must be some idea imprinted by sense upon the mind ; but in perception the ideas of sensations are often changed by the judgment. § 56. In the preceding paragraph we have given, pretty much in Locke's own language, the most important of his doctrines regarding perception. We shall now endeavour to present in more systematic form his solution of the chief psy- chological problems, pointing out those which he has not attempted. (1 .) He appears to assume that the mind is nothing but a capacity of receiving sensations or ideas from experience. In this he differs from Descartes, who cannot doubt the existence of his mind as a thinking PSYCHOLOGY OF COGNITION. Ill CHAP. III. SECT. III. being independent of everything material. The principle of Locke and his school is : There is nothing ill the intellect hut what comes into it through sense; by Leibnitz, a distinguished follower of Descartes and opponent of Locke, this principle is amended by the addition, except intellect itself, (2.) The psychological problem which Locke at- tempts to solve is not how there arises in cpnsci(Mis- ^j^/ *- i>(>v^ ^ ness the knowledge of an extended non-ego, hut\ I <'% *** * * '*^ how the sensive organism assumed to exist conveys to the mind ideas of more distant objects. Locke thus begins from the stand-point of practical dualism. (3.) The mind knows the external world by means of ideas, some of which resemble the qualities which exist in bodies, while others do not. And in this' reference Locke is guilty of the same error which we find amongst the Cartesians ; the idea is evidently thought to be something different from the activity of the_mindjn thinking it ; Locke's psychology may therefore be described as one of representative idealism of the crudest kind. (4.) The primary qualities of bodies are the only real qualities which they possess. The secondary qualities are only poivers to produce certain ideas, as of colour, sound, &c., in us, but these powers are possessed and exercised hy the primary qualities. § 57. With reference to the first position of Locke, that there is nothing in the mind except what comes into it through sense, we may remark that it has occasioned an important and long- continued controversy amongst philosophers. Leib- Locke's 'principle contested hy Leih' nitz. 112 THE ELEMENTS OF THE CHAP. III. i^' Locke assumes dualism. nitz, the ablest contemporary critic of Locke's philosophy^ pointed out that there must be a mind possessing a certain structure or constitution in order to render experience possible. And although Locke may be correct in saying that there are no innate ideas anterior to experience, yet the nature of certain elements of our knowledge is such that they could not be derived simply from experience. There are certain propositions which are characterised by self-evidence and necessity, that is, the truth of which we perceive intuitively and cannot possibly deny. As an example of these propositions we may cite, " Things which are equal to the same thing are equal to one another." This proposition is an ultimate intuition ; it cannot be proved by anything more simple; it cannot be denied, because its opposite is inconceivable. It is argued, therefore, by those who differ from Locke, that the necessity of such a proposition could not originate in experience since experience can only give what is, not what must be; and consequently that there must be something in the constitution of the mind which im- parts the character of necessity to certain axiomatic propositions. § 58. Locke sets out with the resolution to trace the origin of our knowledge, and supposes that the mind at the beginning is destitute of all ideas. The most simple ideas are introduced into the mind through sensBj that is, through the *organs of our physical bodies. And still further, the ingress of the idea through sense is accounted for by some impulse PSYCHOLOGY OF COGNITION. 113 of the primary qualities of external bodies, ^hu^ there is assumed the existence of organs of sense and external bodies, and the problem is to show how the latter, by means of the former, transmit ideas of themselves into the vacant mind. Now there can be no question that this position of Locke is the one which the majority of men naturally occupy. There is in children and savages a complete practical knowledge of objects around them and of their own bodies, although there is thorough ignorance of what is meant by such words as mind, or sensation, or consciousness. In ^tbe-iistorical. acquisition of knowledge, objects are perceived before sensations are known in consciousness. Mankind, without reflection or conscious thought, assumes the stand-point of crude or practical realism, and the great majority of men never leave it. But when one attempts to make a psychological analysis of his knowledge, it is not legitimate to assume objects as existing until it is shown how they become known. § 59. Notwithstanding the implied assumption of the existence of bodies, there is an attempt on the part of Locke to show how the mind knows- external objects. This is by means of ideas which come into the mind through the senses. It is difficult fre- quently to say what Locke means by the word idea, on account of the many different senses in which he uses it, and the inextricable confusion with which different senses of the word are interchanged. There is, however, reason to believe that he was what has been since called a representative or hypothetical CHAP. III. SECT. III. Locke's theory of ideas. 114 TEE JELBMENTS OF THE CHAP. III. SECT. III. realist ; that lie held ideas to be the only things iinmediatfily known; that from the mind^s knowledge of ideas it infers the existence of external qualities y and that the ideas of primary qualities really resem- ble those qualities^ which latter really constitute bodies as they exist. Without undertaking a criticism of some of these positions, which we shall see afterwards is done by others^ we may at present point out an important paralogism. The design of the representative hypothesis is to explain how we come to know external objects. These objects then are assumed to be in themselves unknown ; and their existence is inferred to account for the existence of the ideas which are immediately known. Thus the idiQQi,^jr^X£sent the primary qualities of external objects .ta the mind. Now supposing ideas to exist, - and supposing the inference to be admitted that they have some external cause, we may ask how can it be affirmed that the idea represents or resembles the inferred quality ? In order to assert that one thing resembles or does not resemble another^it is necessary that there should be an independent knowledge of the two things — a comparison between them, and a recognition of their resemblance or non-resemblance» But in this case there can be, ex hypothesi, no inde- pendent knowledge of one of the terms of the com- parison. The quality is known only as an inference from the idea, and hence nothing can be asserted as to its likeness or unlikeness to the idea. The fact is, psychological analysis, in Locke's time, was only in its infancy, and consequently in his writings there 1 PSYCHOLOGY OF COGNITION. 115 was very great confusion in various respects — a confusion wliicli has been to a very great extent cleared away by subsequent writers. § 60. It is to be noticed that, according to Locke, it is the insensible particles of the primary qualities of bodies wliicli produce in us the ideas of the secondary qualities. The meaning of this appears to be that the resisting substance of a body may become so small as not to excite any sensible tactual sensation, but that still it is capable of exci-. ting sensations of sight, smell, or taste. Thus alV ideas are produced by impulse from some extended material substance, but in the case of the primary qualities, the extension is perceived, and therefore the idea resembles the quality, whereas when the extension becomes so small as to be imperceptible, it then gives rise to smells, tastes, and other non- resembling ideas. If this be Locke's meaning, we naturally ask, how is it that secondary qualities do not exist in bodies ? If they are simply primary qualities divided into particles so small as not to offer resistance to pressure, there appears no reason for saying that they have no objective existence at all. This is another instance of Locke's confusion. We must now see how Locke's principles were treated by his successors in psychological research. CHAP. III. SECT. III. Of second. ary quali- ties. I 2 ii6 THE ELEMENTS OF THE CHAP. III. SECT. IV. Berkeley's clearness. New theory of vision. Section IV. BEEKELEY (1684-1753). § 61. When we compare tlie subtlety and clear- ness of the mental analysis found in the writings of Bishop Berkeley with the confusion perceptible in Locke, we might fancy that we had advanced at least a century onwards in the history of thought. In Berkeley we have the first English philosopher who obtained a clear insight into the problems of the psychology of perception. And his solution of some of these problems has not been improved upon to the present day, except, perhaps, in the manner of expression. We shall endeavour to give, as briefly as possible, an outline of the psychological doctrines of which he is the author. Berkeley's Essay towards a New Theory of Vision was his first published philosophical work, and may serve us here as an introduction to his system. In it we have Berkeley's_departure from th^ crude dualismjaf _practical lif^^nd his theory -of the man- ner in which that dualism is established. The fol- lowing are the positions which he takes and defends : " (1.) Distance, or the fact of an interval between two points in the line of vision-^in other words, externality in space, in itself invi_sible — is, in all cases in which we appear to see it, only suggested to our imagination- by certain visible phenomena and visu^sensationSj- which are its arbitrary-signs. PSYCHOLOGY OF COGNITION. 117 " (2.) Magnitude, or the external space that ob- jects occupy, is absolutely invisible ; all that we can see is merely a greater or less quantity of colour, and our apparently visual perceptions of real mag- nitude are interpretations of the tactual meaning of colours and other sensations in the visual organ. '^ (3.) The situation of objects, or their relation to one another in space, is invisible ; all that we can see is variety in the relations of quantities of colour to one another, our supposed pure vision of actual locality being an interpretation of visual signs. " (4.) There is no sensible object common to sight and touch ; space or extension, which has the best claim to this character, and which is nominally the object of both, is specifically as well as numerically different in each, externality in space or distance being absolutely invisible, while size and situation as visible have nothing in common with size and situation as tangible. *' (5.) The explanation of the unity which we attri- bute to sensible things, as complements of visible and tangible qualities of one and the same sub- stance, is contained in the theory that visible ideas and visual sensations, arbitrary signs in a Divine Language, are significant of distances and of the real sizes and situations of distant things; while the constant association in nature of the two worlds of vision and touch has so associated them in our thoughts, that visible and tangible extension are habitually regarded by us as specifically, and even numerically one. CHAP. III. SECT. IV. Ii8 THE ELEMENTS OF TEE CHAP. III. SECT. IV. Suhstance of theory. 5C \/ Objects of knowledge. " (6.) The proper object of geometry is the kind of Extension given in our tactual experience, and not the kind of Extension given in our visual ex- perience, and neither real planes can be seen — real extension in all its phases being invisible, and colour in its modifications of quantity being the only proper object of sight, while colour being a pure sensation cannot exist extra-organically in space." * § 62. The substance of the New Theory may be thus expressed: The perception by sight of dis- tance^ magnitude, and direction, or of bodies as existing without us and being extended, is not an original but an acquired power. In sight we are conscious only of colour, but as this sensation and various tactual sensations are frequently experi- enced contemporaneously, we fancy the object of sight is identical with the object of touch. And since it is the tactual qualities of bodies in which we have the greatest practical interest, visible colour and extension soon, by association, become simply signs to call up the tactual qualities of bodies supposed to be more real. There are some points in connection with this theory which may offer matter for criticism hereafter, but in the mean- time, we shall take a farther view of Berkeley's psychology By quoting from his '^Principles of Human Knowledge,'' part i. : (1.) " It is evident to anyone who takes a survey of the objects of human knowledge, that they are either ideas actually imprinted on the senses; or * Prof. Frazer's analysis in his edition of * ' Berkeley." PSTGHOLOGY OF COGNITION. 119 else suck as are perceived by attending to tlie passions and^ operations of tlie mind; orjlastly, ideas formed by help of memory and imagination — either compounding, dividing, or barely represent- ing those originally perceived in the aforesaid ways. By sight, I have the ideas of light and colours, with their several degrees and variations. By touch, I perceive hard and soft, heat and cold, motion and resistance, and of all these more or less either as to quantity or degree. Smelling furnishes me with odours, the palate with tastes ; and hearing conveys sounds to the mind in all their variety of tone and composition. And as several of these are observed to accompany each other, they come to be marked by^one_iiame. Thus, for example, a certain colour, tastei^sniell, figure, and consistence having been observed to go together, are accounted one distinct thing, signified by^jthe name aj)ple (2.) "But besides all that endless variety of ideas or objects of knowledge, there is likewise something which knows or perceives them, and exercises divers operations, as willing, imagining, remembering, about them. This perceiving, active being is what I call mindy sj^irity soul or my sei?7'^B^y which words I do not denote any one of my ideas, but a thing entirely distinct from them, wherein they exist, or, which is the same thing, whereby they are perceived — for the existence of an idea consists in its beinof perceived. (3.) " That neither our thoughts, nor passions, nor ideas formed by the imagination, exist without the CHAP. III. SECT. IV. Knowing mind. \y Objects have men- tal exist- ence only. 120 THE ELEMENTS OF THE CHAP. III. SECT. IV. No matter. mind, is what everybody will allow. And to me it is no less evident that the various sensations or ideas imprinted on the sense, however blended or combined together (that is, whatever objects they compose), cannot exist otherwise than in a mind perceiving them. I think an intuitive knowledge may be obtained of this by anyone that shall attend to what is meant by the term exist when applied to sensible things. The table I write on I say exists, that is, I see and feel it; and if I were out of my study I should say it existed, meaning thereby that if I was in my study I might perceive it, or that some other spirit actually does perceive it (7.) " From what has been said it is evident there is not any other substance than spirit, or that which perceives For an idea to exist in an unper- ceiving thing is a manifest contradiction, for to have an idea, is all one as to perceive ; that, therefore, wherein colour, figure, &c., exist must perceive them, hence it is clear there can be no unthinhing sub- stance or substratum of those ideas. (8.) " But, say you, though the ideas themselves do not exist without the mind, yet there may be things like them, whereof they are copies or re- semblances, which things exist without the mind in an unthinking substance. I answer, an idea can be like nothing but an idea ; a colour or figure can be like nothing but another colour or figure Again I ask, whether those supposed original or ex- ternal things, of which our ideas are the pictures or PSYCHOLOGY OF COGNITION. 121 representations, be themselves perceivable or no ? If they are, then tliej are ideas, and we have gained our point; but if you say they are not_, I appeal to anyone whether it be sense to assert a colour is like something which is invisible; hard or soft, like something which is intangible ; and so of the rest. (9.) " Some there are who make a distinction betwixt 'primary and secondary qualities. By the former they mean extension, figure, motion, rest, solidity or impenetrability, and number; by the latter they denote all other sensible qualities, as colours, sounds, tastes, and so forth. The ideas we have of these we acknowledge not to be the re- semblances of anything existing without the mind, or unperceived, but they will have our ideas of the primary qualities to be patterns or images of things which exist without the mind, in an unthinking substance which they call matter, therefore we are to understand an inert, senseless substance, in which extension, ngure, and motion do actually subsist, /^ut jb is evident, from what we have already shown, -tiiat extension, figure, and motion are only ideas existing in the mind, and that an idea can be like nothing but another idea, and that consequently neither they nor their archetypes can exist in an unperceiviug substance. Hence, it is plain that the very notion of what is called matter or corporeal snhstance involves a contradiction in it (10.) " We perceive a continual succession of ideas, some are anew excited, others are changed or CHAP. III. SECT. IV, Distinc- tion he- tween qualities fallacioiis. Spirit the objective cause of ideas. 122 TEE ELEMENTS OF THE CHAP. III. SECT. IV. Criticism. Berlceley a presenta- tionist. totally disappear. There is therefore some cause of these ideas whereon they depend, and which pro- duces and changes them. That this cause cannot be any quality or idea is clear It must there- fore be a substance; but it has been shown that there is no corporeal or material substance; it remains therefore the cause of ideas is an incorporeal active substance or spirit.^' § 63. We now proceed to point out some things in Berkeleyanism worthy of remark. And, in the first place, it must be admitted that Berkeley has not carried his psychological analysis quite far enough. When he says, " by sight we have ideas of colour, &c./^ it is plain that he assumes the existence of our sensive organism. And although, according to his theory, the organism is composed, like all other objects, of ideas, yet its existence should not be assumed until it is shown how it is known. There is another defect in Berkeley's analysis which must be admitted. He was^not able to dis- cover the error committed by Descartes and Locke before him of supposing ideas to be distinct entities coatained in a mind. He did not reach the dis- covery that the mental object of consciousness is identical with the mental activity. And con- sequently there is a character of crudeness about his theory which would have been avoided had he taken a correct view of the relation between ideas and mind. § 64. Perhaps the greatest merit -of -Berkeley as a psychologist is his complete overthrow of the PSYCHOLOGY OF COGNITION. 123 representative idealism found in Descartes and Locke. The real objects whicli constitute tlie world in whicli we live are ideas^ tliat is, are objects known ; tbe ideas which are immediately known are the real things which exist. The assumption of some unknown, unthinking matter as the cause of our ideas is unphilosophical and absurd. Ideas cannot represent or resemble anything but ideas ; qualities as known can have no resemblance to matter unknown. The sensible objects which we know are not representatives of any more real matter underlying them ; they are the very things which exist. It cannot be objected to Berkeley's psychology that because he denies the existence of insensible matter he destroys the reality and permanence of things. He believes that the things which he sees and touches would exist whether he saw and touched them or not; that they have a permanent existence because they are always perceived, that is, they always exist in the Divine Mind. The. problem is to account for the permanent objective existence of sensible things. Berkeley's predecessors did this by postulating insensible matter ; Berkeley was success- ful in his destructive arguments against the repre- sentative idealism of his predecessors ; whether he was equally successful in establishing his own posi- tion remains to be seen. § 65. There is probably to be seen in Berkeley's reasoning an illustration of the tyranny of language over thought. He sets out with the assumption CHAP. III. SECT. IV. BerTcelet/s thought controlled by Ian. giULije. 124 THE ELEMENTS OF THE CHAP, III. SECT. IV. Confusion in his use of idea. that everything we know is an idea ; and the very word " idea" compels him to hold that it exists only in a mind ; it is incongruous to think of ideas being anywhere but in a mind. And since unknown, insensible matter is seen by him to be inadequate and contradictory as an hypothesis to account for the permanence of sensible objects, he is driven by his original view of the identity of ideas and things to substitute for matter a mind in which ideas may be contained when his or some other finite mind does not perceive them. Had he commenced with a different view of the nature of ideas ; had he seen them to be not distinct entities capable of existence in different minds, but identical with and insepara- ble from the mental activity of his own consciousness, he probably would have been led to a different con- clusion. We observe also that there is in Berkeley a trace of the confusion in the use of the word " idea" which pervaded Locke. Colours, smells, tastes, are ideas ; so are extension, figure, motion. Now after a careful analysis, there can be nothing clearer than that the sensation of smell or colour is quite different from extension or any form of space. And to class both under the common name " idea'' will almost certainly lead to error. It has led Berkeley to the conclusion tliat_ there is no eioternaUty of objects to his mind except in the mind of some other being. And objects generally have externality from finite minds by virtue of their being contained in the Infinite Mind. Now what is this but saying that the Infinite Mind is practically identical with PSYCHOLOGY OF COGNITION. 125 space, in whicli all sensible objects are perceived ? Thus Berkeley's most important conclusions, regarding the non-existence of insensible matter, regarding the existence of Infinite Mind, regarding the nature of externality, and others, sprang from an erroneous view regarding the nature of ideas, and an indiscriminate application of the word " idea" to things essentially different. But although in the expression, and perhaps also in the meaning, of his doctrines he is not free from error, it must always be admitted that in his hands psychology began to be characterised by that subtlety and clearness of analysis which are so difficult of attainment, and yet so essential to its taking a position worthy of its importance in the circle of the sciences. Section V; HUME (1711-1776). § QQ. David Hume was the natural successor in philosophy of Locke and Berkeley, and he carried their principles to a logical conclusion. The same clearness and acuteness of analytic power which we observed in Berkeley are to be found in perhaps a still greater degree in Hume. The publication of his writings constituted a crisis in modern philosophy which led his successors to go back to the considera- tion of the premises from which modern philosophers started, in order that they might avoid his conclu- CHAP. III. SECT. V. 126 THE ELEMENTS OF THE \ CHAP. Ill, SECT. V. Hume's doctrines. Impres- sions and ideas. Simple and com- plex per- ception. Character and rela- tions of impres- sions and ideas. sions. We shall give in his own words his most important doctrines. " All the perceptions of^the human mind resolve themselves into two distinct lEinds^'wEch 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 and consciousness. These 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.^^ * "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 complex. 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. Though a particular colour, taste, and smell, are qualities all united together in this apple, it is easy to perceive they are not the same, but are at least distinguishable from each other/^ f "All our simple ideas in their first appearance are derived from simple impressions which are correspondent to them, and which they exactly represent.'-' J "Impressions may be divided into two kinds, * Works, i., p. 15. f lb. i., p. IG. % lb. i. p. 18. PSYCHOLOGY OF COGNITION. 127 those of sensation and those of reflection. Tlie_first kind arises on tlie soul originally from unknown causes. ^TEe 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 remains 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." * With reference to the suhstratiim of bodies, Hume a^ks " whetherthe id¥a of suhstance be derived from the impressions of sensation or reflection ? If it be conveyed to us by our senses, I ask which of them, and after what manner ? If it be perceived 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 some will assert that sub- stance is neither a colour, a sound, nor a taste. The idea of substance must therefore be derived from an impression of reflection if it really exist. But the impressions of reflection resolve themselves into our passions and emotions, none of which can pos- sibly represent a substance. We have, therefore, no idea of substance distinct from that of a collec- "orfesii,, p. 22. CHAP. III. SECT. V. Substance f what. 128 THE ELEMENTS OF THE CHAP. III. SECT. V. Extension tion of particular qualities, nor liave we any other meaning when we either .talk or reason concerning \i^. 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 imagination and have a par- ticular name assigned them, by which we are able to recall, either to ourselves or others, that collec- tion. But the difference betwixt these ideas consists in this, that the particular qualities which form a substance, are commonly referred to an unknown something f in which they are supposed to inhere ; or at least supposed to be closely and inseparably connected by the relations of contiguity and causa- tion/'* '^Upon opening my eyes and turning them to the surrounding objects, I perceive many visible bodies; and upon shutting them again, and con- sidering the distance betwixt these bodies, I acquire the idea of extension. As every idea is derived from some impression which is exactly similar to it, the impressions similar to this idea of extension must either be some sensations derived from the sight, or some internal impressions arising from these sensations." It is not the latter, therefore it must be the former. '^ My senses convey to me only the impressions of coloured points, disposed iu a certain manner. Hence we may conclude with certainty that the idea of extension is nothing but a copy of these coloured points and of the manner of their appearance."''t * Works, i., p. 32. f lb. i., p. 53. PSYCHOLOGY OF COGNITION. 129 Thus Hume concludes that extension is an idea abstracted from particular impressions of sense, the peculiarities of colour, &c., being left out of view, and attention paid only to the disposition of points. "As it is from the disposition of visible and tangible objects we receive the idea of space, so from the succession of ideas and impressions we form the idea of time; nor is it possible for time alone ever to make its appearance, or be taken notice of by the mind/^* "We have no idea of space or extension but when we regard it as an object of our sight or feeling. So the indivisible movements of time must be filled with some real object or existence, whose succession forms the duration, and makes it to be conceivable by the mind.^'^f "As to those impressions which arise from the senses, their ultimate cause is, in my opinion, per- fectly inexplicable by human reason, and it will always be impossible to decide with certainty, whether they arise immediately from the object, or are produced by the creative power of the mind, or are derived from the Author of our being/^ J " The opinion of the continued existence of body depends on the coherence and constancy of certain impressions.'^ § § 67. Having given the important psychological doctrines of Hume in his own language, we now proceed to make such remarks upon them as seem Works, i., p. 54. + lb. i., p. 59. § lb. i., p. 246. X lb. i., p. 113. K CHAP, III. SECT V. \/ Time. Space. Cause of phenome' na inex- plicable. Objectivity explained. I30 THE ELEMENTS OF TEE CHAP. III. SECT. V. Doctrines % called for. But before doing so we shall arrange more systematically tlie doctrines to whicli we pro- pose to refer. (1.) All our simple ideas are copies of some im- pressions previously experienced. No idea, there- fore, can be found in the mind which has not, more or less proximately, been copied from some im- pression. (2.) There is no idea in the mind of suhstance, either corporeal or spiritual, except in so far as substance means a collection of qualities or of impressions and ideas. This doctrine follows im- mediately from the preceding, since substance is admitted to be neither a sensation nor the copy of a sensation. (3.) Extension and duration, or space and time, are ideas abstracted from sensations. The idea of extension is a copy of the co-existent points of visible or tactual impressions. The idea of duration is a copy of the continuity of sensations. But as abstract ideas have no existence independent of the concrete impressions from which they are abstracted, it follows that space and time have no existence independently of extended or continuing impres- sions. (4.) It is impossible to infer with certainty the cause of sensations. The metaphysical hypothesis of an insensible substance as the cause of sensations, has been shown to be contradictory. And it is like- wise impossible to infer, with Berkeley, that the Divine Mind is that cause. PSYCHOLOGY OF COGNITION. 131 (5.) If it be asked how objects, tbat is, collections of impressions, appear to have a continued and in- dependent existence, the only answer that can be given is, that the impressions composing them are seen to have a certain coherency and constancy of recurrence which leads the mind to attribute to them independent existence. § 68. The first of these principles held by Hume is only a re-statement in more definite form of what, long before, had been held by Locke. But in Hume's hands it became a powerful instrument of destruction. We have no ideas except those that are copies of some antecedent impressions. But matter as a substratum is not given in any sen- sation ; neither is mind as the subject of ideas ; neither is causal efficiency, except merely that one impres- sion or idea regularly precedes another ; neither is God. Therefore we have no idea of matter, or mind, or cause, or God. This ought to be Hume's con- clusion ; but he actually concludes that we cannot infer the existence of these unknown things. This principle, drawing with it, as it did, such sceptical conclusions, was most important in stimulating Reid and Kant to inquire into its accuracy. "Vf e shall, therefore, leave the criticism of it to them, merely pointing it out now as the principle which, by its consequences, led to the greatest revolution in the history of philosophy. § 69. We now consider one of Hume's sceptical conclusions. He holds that we have no idea of ■substance except as a collection of qualities or im- K 2 CHAP. III. SECT. V. Criticism. Sceptical results. Huyne's doctrine of substance. 13- THE ELEMENTS OF THE CHAP. III. SECT. V. pressions; no idea of it as the unknown cause of our known sensations. He holds, also, that it is impos- sible to infer conclusively that our simple sensations are caused by the Divine Mind. But_, at the same time, there is an admission that sensations must have an origin somehow and somewhere. Sensations, he says, ''arise on the soul originally from unknown causes. An impression first strikes upon the senses and makes us perceive heat or cold," &c. There is here, consciously or unconsciously, an admission that there is something beyond, or behind our sensations, which we cannot indeed hnoiu, but the existence of which we cannot deny. Connected with the origin of our sense-knowledge — that is, connected with the real existence of things — there is, Hume admits, a problem to be solved, which, however, he thinks in- soluble. " An impression strikes upon our senses.^^ Take almost any one of these words, and you cannot understand its meaning without taking for granted that very unhioivn which Hume wished to banish. Impression implies some receptive thing upon which some other thing presses, so as to leave its mark. What is that other thing which makes the impres- sion upon the senses ? Hume cannot answer ; but he cannot employ ordinary language, he cannot invent a language which does not imply that beyond the sphere of our immediately known sensations there is another sphere which we are bound to believe in but may not completely know. Hume started with the assumption that we have no ideas but what are copies of sensations, and the sceptical conclusions to PSYCHOLOGY OF COGNITION. 133 whicli he was led are tlie reductio ad ahsurdum of his principle. His principle landed him in a conflict with beliefs of which he could not rid himself, and he certainly showed great fortitude in throwing over- board those beliefs for the sake of logical consistency. But it is questionable if he was really sincere in doing so, and there is some reason for supposing that his design was simply to show the absurd conclusions to which his predecessor's principles naturally led. This at least he did, and did it with remarkable effect. § 70. Hume's view of the origin of the idea of ex- tension must now be referred to. As he was not at liberty to admit any idea which was not a copy of a sensation, and as he could not deny that we have an idea of extension, he was bound to show that it was a copy of some sensation. He accordingly assumed that sensations or impressions, as he called them, were extended ; then abstracted his mind from the quality of the sensation, as colour, &c.; then as the result of the abstraction appears the idea of pure extension. And as the idea is a copy of the sensation omitting the particular colour or tactual quality, it follows, of course, that the idea is extended. But as it is an abstract idea, it can have no existence apart from the concrete sensation from which it was abstracted. One would have supposed that the in- congruity of making an idea a copy of an extended thing would have been sufficient to make Hume abandon his principle altogether. But no ; with a pertinacity worthy of a better cause he determines CHAP. III. SECT. V. Extension. 134 THE ELEMENTS OF THE CHAP. III. SECT. V. General view of psycholo- gical 'prol)- lems. that^ come wliat will, lie will adhere to liis principle. His doctrines^ tliat tlie idea of extension is a copy from a sensation^ tliat space and time are abstrac- tions from concrete experiences, will be criticised hereafter.* § 71. As the scepticism of Hume formed such an important crisis in the history of modern philosophy, and as it is the natural conclusion of all that went before, it may be as well to present in a brief form a view of the important problems which had hitherto occupied the attention of psychologists, and the ways in which their solution was attempted. The diagram on the next page is an attempt to illustrate, in a rough way, the problems which psychologists have set themselves to solve. Let the circle R, 0, H, T, S, with I in the centre, represent the mind and its sensations ; R, indicating resistance, C, colour, H, hardness, T, taste, S, smell. I indicates the ego or subject of consciousness. The capital letters R, C, &c., indicate actual sensations, and, since they are felt in the body, B, E, the circumscribed circle, may represent the extension of the organism. The small circle to the left hand, r, c, h, t, s, indicates the mind in a state of reflection, and each of these letters stands for the representative or the idea of the sensation indicated by the corre- sponding capital. The circle to the right hand, having in the centre, indicates the object, supposed to have independent existence, and consisting of the qualities R^, C^, &c.,all comprehended in E^, ]E^, objec- * See § 89. P8YCS0L0GY OF COGNITION. 135 tive extension. The small circle at the extreme right may represent the unknown matter, consisting of unknown powers, r^, c^, &c., corresponding to the known qualities, R^, C^, &c., which constitute the object of perception. § 72. Now, in examining the problems connected with the process of knowing and the objects of know- ledge, there have been adopted, as we have pointed out, two methods. According to the first of these, the continuous and independent existence of the object is assumed, and the problem is to explain the relation between and I, between the extended object and the perceiving mind. And as it is also assumed that I and are so utterly different in nature that the former cannot know the latter, it becomes necessary to interpose between them some intermediate and representative idea. Hence, the sensations E, C, H, &c., or the revived sensations r, c, h, &c., or some combinations of them, are thought to be representatives of the object and its qualities. But after a more careful analysis, it comes to be seen that some of the qualities, such as C^, H^, T^, S^, are really identical with sensations C, H, T, S, and when this discovery is made, there must be a correction of CHAP. III. SECT. V. Methods of studying them. Represen- tative theory. 136 THE ELEMENTS OF THE CHAP. III. SECT. V. Modified. Over, thrown. the representative theory. C, colour, is purely sub- jective, and so are H, T, S, therefore there are no qualities C^, H^, T^, S^, to be represented, nothing bub certain unknown powers, c^, h^, t^, s^, consequently the sensations C, &c., which are immediately known, are made to represent these unknown powers. But here another difficulty presents itself. How can you say that something which is in itself utterly unknown is represented by something that you know ? And, especially, how can you maintain that ideas of your mind are ideas of an unknown and unknowing matter ? These are the questions that Berkeley asks, and by them overturns the representative theory. The sensations R, C, &c., are not representatives at all ; they are the real things which exist. They are identical with R^, C^, &c., the distance and externality being only apparent not real. Scepticism regarding matter and space, begun in Berkeley, is continued and extended in Hume. All knowledge comes through sensation. But matter is not a sensation, neither is cause, neither is spirit, therefore these things do not exist. There are only the two series of sensations and ideas governed by certain laws. Thus, psychology, beginning with the assumption of practical dualism, is compelled to make use of a theory of representation to explain its difficulties, finds this theory unsatisfactory, and terminates in scepticism. As the representative theory played such an important part in psychology from Descartes to Hume, it may be serviceable to us to give some attention to the nature of representation and the PSYGEOLOGY OF GOGNITION. 137 use which has been properly or improperly made of it. § 73. Turning to the diagram in § 71 it is proper to say that c represents C ; a revived sensation re- presents correctly and more or less vividly the original sensation of which it is a revival. But suppose an object of perception, say an orange, lies before us. A certain figured colour is seen, called by Locke and others an idea. This idea represents the object. Now 'this use of the word represent is utterly confusing and inaccurate. For what does it mean ? It means that the sensation C represents C^, 4- r + t + s ; or that the sensation of colour repre- sents the quality of colour plus the other possible and imagined sensations of resistance, smell, taste, &c. which we believe we may experience from the orange. Now it may be quite correct to say that the sen- sation C calls up before consciousness by the power of association certain other revived sensations which have previously occurred in the same group with C ; it is quite incorrect to say that C represents them. A third use of the principle of representation makes C represent C^, the sensation represent the quality. But the truth is that the sensation is the quality as far as we know it. Sensations associated together and, by an organic process, projected into space are the objects which we hnow. It may be said, in the fourth place, that the sensation C represents the unknown power c^, and this is quite as inaccurate a use of the word as any of the rest, as has been already shown. Thus in the first and only proper CHAP. III. SECT. V. Different meanings of repre- sentxition. 138 TEB ELEMENTS OF TEE CHAP. III. SECT. V. Ground of reaction. use of tlie word represent, it raeans both to stand for and resemble; in tbe second it means to be associated witb. so as to bring into consciousness ; in the third it expresses the result of an organic illusion ; and in the fourth it indicates an inference which we make regarding the cause of our sensations. The impropriety of regarding ideas as representatives in any of these senses except the first was clearly perceived by both Berkeley and Hume; and the errors of these philosophers, if such there are, must be looked for, therefore, in their views of the nature or origin of ideas. The former thought that all ideas, that is, objects of knowledge, must, as being ideas, exist in some mind; the latter maintained that all ideas are copies of some sense impression. Hence the idealism of the former and scepticism of the latter. § 74. The conclusion of Berkeley and Hume may be regarded as the reductio ad absurdum of represen- tative idealism g,s found in Descartes and Locke. But in these conclusions there was something un- satisfying to the human mind. People can scarcely bring themselves to think that the objects which they perceive have or involve no reality except the fact of their being perceived. Nor is it easy to think that space, or the externality of objects with reference to our minds, means simply the possibility of being perceived by another mind. It was there- fore to be expected that there would be a reaction against the conclusions of Berkeley and Hume ; and that that reaction would seek to establish — first, the PSYCHOLOGY OF COGNITION. 139 permanent and independent existence of a non-ego other than a mental one ; and second, the existence of ideas which are not merely copies of sensations. By the efforts of Keid and Kant this was attempted. Section YI. EEiD (1710-1796). § 75. Reid, like many other people of his time, was greatly shocked at the sceptical conclusions drawn by Berkeley and Hume, and he set himself with great ardour to refute the system from which he believed them to follow. The conclusions that there is no matter and no mind, that all the objects in the universe are nothing but floating impressions and ideas, were so utterly repugnant to his practical good sense, and so utterly repugnant to the ordi- nary beliefs of mankind in general, that he resolved to see whether some foundation for philosophy could not be laid upon which it would be possible to build more securely the structure of human knowledge and belief. To this task Reid brought a great deal of candour and honesty, a fair amount of learning, and a great deal of good sense. But unfortunately he did not understand either Berkeley or Hume, and he was not at all clear as to what position he ought to take up in order success- fully to refute them. He resolved to appeal from the philosophers to the common sense of mankind, which is a more or less satisfactory appeal accord- ing to what is meant to be included in the term CHAP. III. SECT. vr. Reid shocTced, 140 THE ELEMENTS OF THE CHAP. III. SECT. VI. Reid militant. Reid versus ideas. common sense. G-enerally speaking, he appears to mean bj it that practical good sense which leads men to trust to the testimony of their senses, and to believe in the existence of the world and a variety of other things. Sometimes, however, he gives it a more scientific meaning, and describes the prin- ciples of common sense as those beliefs which result from the constitution of our nature, and which are necessary and universal. Then taking his stand upon these principles, he thought that he was able to defy the most insidious attacks of the sceptic. Like the good knight, FitzJames, he addressed his foes, the idealistic philosophers : — " Come one, come all, this rock shall fly From its firm base as soon as I." But, unfortunately, it was not long before he went over to the camp of the enemy, cut his con- nection with his first friends, the men of common sense, and began to philosophise just as recklessly as any that had gone before him. § 76. We must now proceed to consider what it was that he accomplished or attempted in the in- terest of psychological science. And at the outset we observe with satisfaction that he noticed the improper use which his predecessors had made of the word"idea.'' He saw that there was no mental object numerically different from a mental activity ; that the act of conceiving and the mental concept were really identical, being the same thing looked at from different sides. Consequently, when he PSYCHOLOGY OF COGNITION 141 speaks of ideas or any other mental objects, lie considers them as equivalent to mental activities or states. He brought into prominence also the fact, wbicli Berkeley Lad clearly pointed out before him, that the ideas or phenomena of the mind do not at all resemble the qualities which he believed to exist outside of him and to constitute the material world. There can be no resemblance between the sensation of colour and the objective quality which causes it; nor between the sensation of touch or pressure and the objective hard and extended body which occasions it. Thus thought Eeid; and in establishing this position he believed that he had overthrown the idealistic hypothesis. If there are no ideas in existence except mental activities, and if these bear no resemblance to qualities of matter, how can there be any pos- sibility of reasoning from those mental pheno- mena to either the existence or the non-exist- ence of unknown material qualities ? Thus Reid pronounced the demonstration of the existence of a material world, upon principles of idealism, to be impossible ; equally impossible was the demon- stration of its non-existence. And having thus shown the futility of the method of demonstration as applied to the problems of the psychology of perception, he took refuge in the instinctive beliefs of mankind from that scepticism in which he believed the principles of idealism terminated. Thus far we have considered Reid as a destructive thinker, overturning the false positions of his pre- CHAP. III. SECT. VI. 142 THE ELEMENTS OF THE CHAP. III. SECT. VI. Percep- tion. Colour. decessors ; we must now study his efforts towards the establislimeiit of a true tlieory of perception. § 77. '' If/' says Reid, ''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 object perceived ; secondly, a strong and irresistible conviction and belief of its present existence ; and thirdly, that this conviction and belief are immediate, and not the effect of reasoning.'^* And again, when examining the sense of touch, he finds that his conception of hardness is unlike any sensation and therefore not an idea of sensation ; and also that the belief of the existence of hardness cannot be the result of any comparison of ideas or reasoning, he concludes thus : — '' What shall we say, then, of this conception and this belief, which are so unaccount- able and so untractable? I see nothing left but to conclude that, by an original principle of our constitution, a certain sensation of touchboth suggests to the mind the conception of hardness and creates the belief of it : or in other words, that this sensation is a natural sign of hardness.'^f In speaking of colour, he says : — " The common language of man- kind shows evidently that we ought to distinguish between the colour of a body, which is conceived to be a fixed and permanent quality in the body, and the appearance of that colour to the eye, which may be varied a thousand ways, by a variation of the light, of the medium, or of the eye itself. The permanent * Hamilton's "Reid," i., p. 258. t Hamilton's "Reid," i., p. 121. PSYCHOLOGY OF COGNITION. 143 colour of the body is tlie cause whicli, by the media- tion of various kinds or degrees of light and of various transparent bodies interposed, produces all this variety of appearances The ideas of sight come to be associated with and readily to suggest thiugs external and altogether unlike them. In particular, that idea which we have called the ap- ^earance of colour , suggests the conception and belief of some unlmown quality in the body which occasions the idea, and it is to this quality, and not to the idea that we give the name of colour/'* Eeid's account of the perception of the primary qualities is substan- tially the same as of the secondary. An impression is made upon the retina of the eye, or a tactual sensation is felt in the hand ; and these severally suggest visible and tangible figure and extension by some instinctive principle of our constitution which we cannot explain and cannot resist. § 78. Arranging the foregoing doctrines more systematically, the following appear to be the essential principles of his theory of perception : — (1.) Qualities as they exist in bodies are, in them- selves, absolutely unknown . This is true both of the secondary and primary qualities, since no sensation or idea of which we can be conscious has the slight- est resemblance to either the one or the other. (2.) The only objects which we can know are sensations or ideas, but these are not to be distin- guished from the mental acts which they constitute. (3.) These sensations or ideas are of various kinds ; I* Hamilton's " Reid," i., p. 137. CHAP. III. SECT. VI. Primary qualities. Doctrines arranged. 144 THE ELEMENTS OF THE CHAP. III. SECT. VI. Beid's de- parture from, com- mon belief. and, by an original principle of our constitution whicli we cannot explain^ suggest the conception of some corresponding objective but in itself unknown quality, and create in us a belief of its existence. This suggestion of the conception and belief of th& unknown quality is what Reid means by perception. (4.) The suggestion, by the sensation, of the con- ception and belief of the quality, is immediate, that is, the mind passes from the " sensation to the con- ception and belief of the quality without the medium of any process of reasoning, but by an instinctive and irresistible principle of our constitu- tion. We have not been able to find in Reid a single passage in which immediate means anythiog but this. § 79. We can now point out the differences between Reid and his predecessors, and form an estimate of the value of his attempt to advance psychological science. We have already stated that he professed to adhere to the generally-received beliefs of man- kind, but that he soon departed from the stand- point of men of common sense. The qualities of bodies are, according to him, unknown ; the appear- ance of colour, for example, the phenomenal colour, is known to us, and suggests the existence of an unknown c^use which exists permanently in bodies. But ask any ordinary man of common sense, and he will tell you that the colour which he sees exists in bodies. All men who are not philosophers believe that the greenness and the redness of which they become aware through sight really exists in bodies PSYCHOLOGY OF COGNITION. 145 outside of them, and tliey do not know the meaning of a colour which cannot be seen. Reid tells them, *^ Oh no ! my friends, your principles of common sense are generally correct, and what you cannot help but believe is generally true; but in this case there is a slight mistake. What you see, the blue- ness or the redness, is not the colour of bodies at all ; it is nothing but an idea in your mind. The real colour of bodies is something that you cannot see ; an unknown quality whose existence is sug- gested to you by that delusive appearance of colour which you incorrectly believe to be in bodies.'" There is reason to fear that Reid's friends of common sense would think his doctrine, that the colour of bodies is something invisible, rather paradoxical. § 80, The principal differences between ordinary men, Reid, and the idealistic philosophers whom he opposes may be resolved into an ambiguity in the use of language. Turning again to the diagram in § 71, all men who are not philosophers look upon C^ as the only colour which they know; they see it and believe it exists in bodies. Reid tells them that 0^ is really C, an idea, and that it is incorrect to call it a colour. The real colour is c^, an unknown quality. Reid's opponents, the philosophers, agree with Reid in identifying C^ with C, but they say that C is the colour and not c^. Here is only a difference in the application of a name. But there are other differ- ences of greater importance. According to Reid, the sensations of which we become aware through the organism necessarily L CHAP. III. SECT. VI. Philoso- phical Ian. guage am. higuous. Suggestion of qualities necessary. 146 THE ELEMENTS OF THE CHAP. III. SECT. VI. Extension not derived from sen- sation. suggest external and otherwise unknown qualities,, and, by tlie constitution of our nature, we cannot hut believe in the existence of those qualities. To attempt, therefore, either to prove or to disprove their existence is absurd ; they are given to us by a law of our nature more fundamental than any process of reasoning we might employ. And any system of philosophy which results in the subversion of this natural and necessary belief must bo fallacious either in its original premises or in somo of its intermediate processes. Thus to the scepticism of Hume, Reid opposed his^ doctrine of the necessary suggestion and belief of objective qualities. What is necessarily believed cannot possibly be doubted; the existence of the qualities of bodies is, by a necessity of our nature, believed ; therefore Hume's scepticism is impossible. Such was the reasoning of Reid; and if he could make out the alleged necessity, there can be no- question but his reasoning was correct. But,, unfortunately for his position, both Berkeley and Hume found it possible to doubt that which Reid pronounced to be necessary, and the possibility of an honest doubt is a clear disproof of an alleged necessity. Another ' doctrine of Reid's, which he himself thought to be of great importance, was directed against one of the premises of idealism. Since the time of Locke it was an accepted maxim amongst English psychologists that all our ideas originate in sense. Upon the principle that there can be no idea PSYCHOLOGY OF COGNITION. H7 wHicli is not tlie copy of a sensation, Hume founded Ms sceptical conclusions. And Reid, therefore, saw tlie importance of endeavouring to show the falsity of this principle. He took the idea of extension as an exjperimentiim crucis ; showed that none of our sensations can be extended, while at the same time it cannot be denied that we have a knowledge of extension ; and then triumphantly asked where this knowledge could come from. Since it could not possibly come through sense, no sensation being extended, the idealists, Reid thought, must find it utterly impossible to explain its origin upon their princip]es, while he himself had his instinctive beliefs to fall back upon. Extension is suggested, necessarily and inexplicably, by non-extended sensa- tions, and it has an objective existence as a primary and essential quality of bodies. These two points, the necessity of believing in the existence of objective qualities, and the origin of our knowledge of extension or space, are thought by Reid to be the most important parts of his philo- sophy. But perhaps if he and his opponents, the idealists, had understood one another better, there would not have appeared to be such great differences between them. Note on Reid's Doctrine of Peeception. A distinguished modern psychologist. Sir W. Hamilton, has attempted to show that Reid held, in reference to perception, the doctrines of Natural Realism, which Hamilton himself professes L 2 CHAP. III. SECT. VI. ^ 148 THE ELEMENTS OF THE CHAP. III. SECT. VI. Is Beid a Natural Realist ? to hold, and whicli he regards as of first importance. In his twenty- third lecture of the Metaphysical Course Hamilton sums up his examination of Eeid's doctrine by pointing out four suppositions upon which Reid must be held to be a Natural Realist. These are : — (1) If he maintain that his immediate perception of external things is convertible with their reality ; (2) if he assert that, in his doctrine of perception, the external reality stands to the per- cipient mind face to face, in the same immediacy of relation which the idea holds in the representative theory of the philosophers; (3) if he declare the identity of his own opinion with the vulgar belief, as thus expounded by himself and the philo- sophers ; • or (4) if he declare that his perception affords us equal evidence of the existence of external phenomena, as his consciousness affords us of the existence of internal. And Hamilton adduces quotations, which we shall examine, to show that all these suppositions are fulfilled in Reid^s doctrine. In support of the first and second, he adduces the following : — " We have before examined the reasons given by philosophers to prove that ideas, and not external objects, are the immediate objects of per- ception. We shall only here observe, that if external objects be perceived immediately we have the same reason to believe their existence as philo- sophers have to believe the existence of ideas, while they hold them to be the immediate objects of per- ception.^' (" Works,'' p. 446.) From this quotation, according to Hamilton, we are to conclude that Reid holds that to be perceived means the same as to exist, and that, in perception, the external reality stands face to face to the per- cipient mind in the same immediacy of relation as PSYCHOLOGY OF COGNITION. 149 the ideas of the philosophers stand to conscious- ness. A fair reading of the quotation should lead us, we think^ to this conclusion : — that the immediate per- ception of external objects is as sure a guarantee of their existence as the consciousness of ideas is of their existence. It is one thing to say that percep- tion is a guarantee of existence or reality ; it is another thing to say that perception is convertible with existence or reality. The latter was said by Berkeley, but Reid did not understand the doctrine and never expressed it. All that Reid meant to say was that we should place as implicit confidence in our perception of external objects as philosophers do in their consciousness of ideas. And none but madmen or fools have ever doubted this. But in saying this he asserts nothing whatever regarding the character of perception. He tells us, however, that external objects are the immediate objects of perception, and here we appear to have something said regarding the nature of perception. But the question arises, What does Reid mean by immediate ? There are two meanings of this term which it is of importance for us to discriminate. The first of these may be called the psychological meaning, and in this sense the term is used by Hamilton. In this sense immediate knowledge means knowledge in which the object is present to consciousness itself and not through the medium of any representation. The second of these may be called the logical meaning, and in this sense immediate knowledge means hioivledge which is obtained directly without the intervention of a process of proof or inference. Now when Reid says that the objects of the external world are the immediate objects of perception, we cannot CHAP. III. SECT. VI. Immediate perception, xohat ? Two mean, ings of im. mediate. 150 THE ELEMENTS OF TEE CHAP. III. SECT. VI. decide whether he is a Natural Realist, until we have determined whether he uses the term in its psychological or in its logical significance. He might use the term in its latter sense without having the most remote idea of the meaning of that immediate knowledge which is asserted in Natural Realism. A few quotations from his writings will show in what sense he uses it. " In the meantime, I beg leave to think with the vulgar, that when I remember the smell of the tuberose, that very sensation which I had yesterday and which has now no more any existence^ is the immediate object of my memory.-" ("Works," p. 106.) It is simply impossible that immediate can be used here in the 'psychological sense, since the so-called immediate object now no longer exists. And immediately below this passage he explains himself in such a way that we must conclude that he had the logical meaning of the word in his mind. " If you ask me,^^ he says, " why I believe that the smell exists, I can give no other reason, nor shall ever be able to give any other than that I smell it. If you ask me why I believe that it existed yester- day, I can give no other reason but that I remember it.^^ Manifestly immediate y of the first quotation, is identical in meaning with I can give no other reason, of the second. That is, it is used in its logical sense. Again, in his essays upon the Intel- lectual Powers, Reid says : " If, therefore, we attend to that act of our mind which we call the percep- tion of an external object of sense, we shall find in it these three things : — First, some conception or notion of the object perceived ; Secondly, a strong and irresistible conviction and belief of its present existence; and, Thirdly, that this conviction and PSYCHOLOGY OF COGNITION. 151 belief are immediate and not the effect of reasoning .''^ {" Works/' p. 258.) Here Keid himself indicates as clearly as possible that tbe term immediate is used in its logical sense. And in explaining tbe tbird of the above points be enlarges upon tbe fact tbat no process of reasoning is involved in perception. But throughout his writings we have nowhere been ^fe to discover the idea of psychological immedim which is involved in the doctrine of Natural E-ealism. Hamilton's third point is that Reid declares the identity of his own opinion with the vulgar belief. What can be established by this it is difficult to see. Berkeley declared the identity of his opinion with the vulgar belief; and yet Reid is very far away from the position of Berkeley. Reid declared the identity of his opinion with the vulgar belief, and yet he maintained, contrary to vulgar belief, that the appearance or idea of colour is in the eye ("Works," p. 137) and that the colour of an external object is something unseen and unJcnown ("Works," p. 138). Hamilton declared the identity of his opinion with the vulgar belief, and yet he held that the immediate object of perception is in all cases in immediate contact with the organism, a proposition which the vulgar can neither understand nor be- lieve. An appeal to uncritical, unenlightened, vulgar belief is surely unworthy of a philosopher. In the fourth place, Hamilton tells us that if Reid " declare that his Perception affords us equal evidence of the existence of external phenomena, as his consciousness affords us of the existence of internal " he must be a Natural Realist. But surely it is possible to hold that we can place implicit con- fidence in the truth of perception without holding CHAP. III. SECT. VI. £//»n, Appeal to vulgar belief. Certainty of evi- dence. 152 TEE ELEMENTS OF THE CHAP. III. SECT. VI. that the object of perception is immediately present to the mind. The essential point of natural realism is that the non-ego is immediately present to and known hy the ego ; but this point is not involved in the assertion that perception gives us certain evi- dence of its object. The longest train of mathe- matical reasoning gives us certain evidence of the truth of its conclusion, but this fact vouches nothing as to the character of the reasoning pro- cess. Neither does the certainty of perception vouch anything as to the character of perception. The fact is that Reid knew no more about the doctrine of natural realism than Berkeley knew about Kant's doctrine of the subjectivity of space. Although Berkeley came very close to the doctrine of natural realism, Reid did not even understand him, and it appears to be a foolish anachronism to attribute to Reid a doctrine which had then scarcely dawned upon the minds of psychologists. Reid's doctrine of perception was a slight advance upon that of preceding representationists. He held that sensations, hy a natural and irresistible prin- ciple of our constitution, suggest to our minds the conception and create the belief of external objects, and that this suggestion is immediate and not the effect of reasoning. How this can possibly be inter- preted as a form of natural realism, and ivhy the attempt should be made thus to interpret it, tran- scend the present writer's power of imagination to conceive. We must now see how the scepticism of Hume was met by a German thinker far more profound than Reid — Immanuel Kant. PSYCHOLOGY OF COGNITION. 153 Section VII. KANT (1724-1804). § 81. It was the negative scepticism of Hume ^hich stimulated Kant to produce his great work, le " Kritik of the pure Reason." He saw, as Eeid dso did, that Locke's principle regarding the origin )f knowledge naturally led to Hume's conclusion. |If all our ideas are simply modified sensations, if all >ur knowledge arises out of experience, many of our lost cherished and valuable beliefs must be under- mined. Hence, Kant set himself to show that, although '' all our knowledge begins ivith experience," yet " it by no means follows that all arises out of our experience.'^ There are certain elements of our knowledge which could not be derived from ex- perience. " Experience, no doubt, teaches us that this or that object is constituted in such and such a manner, but not that it could not possibly exist otherwise. Now, if we have a proposition which con- tains the idea of necessity in its very conception, it is a judgment a priori ; if, moreover, it is not derived from any other proposition, unless from one equally involving the idea of necessity, it is absolutely a priori. An empirical judgment never exhibits strict and absolute, but only assumed and comparative universality."* To show that there are such necessary and univer- sal judgments Kant appeals to the sciences of mathe- * Kant's "Introduction." CHAP. III. SECT. VII. Kant*s Kritik. Origin of knowledge. 154 THE ELEMENTS OF TEE CHAP. III. SECT. VII. Sensation. Matter and Form. Space. matics and physics. We are not concerned with the general use which he makes of this distinction between the d priori and the empirical elements of knowledge ; we have only to study its application to the psychology of perception. And in this we shall see a very important difference between the German and the Scottish opponent of Hume. § 82. According to Kant, sensation is the result of objects affecting our sensibility or sensive faculties in a particular way. Thus, by means of sensation, we have an intuition of phenomenal objects. Tbat in the phenomenon which corresponds to the sensation, Kant calls its matter; but that which effects that the content of the phenomenon can be arranged under certain relations, he calls its form. But that in which our sensations are merely arranged, and by which they are susceptible of assuming a certain form, cannot be itself sensation. It is, then, the matter of all phenomena that is given to us d posteriori, the form must be ready a priori for them in the mind. By an easy analysis, Kant reaches the conclusion, that the two forms of intuition, without which the cognition of phenomena would be impossible, are space and time. It is with the former that we are now concerned. The following are the principal elements of 'Kant's exposition of space: — (1.) ^^ Space is not a conception which has been derived from outward experiences. For in order that certain sensations may relate to something without me, and in order that I may represent them, not merely as without of, and near to each other. PSYCHOLOGY OF COGNITION. 155 but also in separate places, the representation of space must already exist as a foundation. (2.) " Space, then, is a necessary representation d 'priori, which serves for the foundation of all external intuitions. (3.) " Space is no discursive, or as we say, general conception of the relations of things, but a pure intuition. (4.) " Space does not represent any property of objects as things -in- themselves, nor does it represent them in their relations to each other. (5.) ^^ Space is nothing else than the form of all phenomena of the external sense, that is, the subjective condition of the sensibility under which alone external intuition is possible." The substance of Kant's doctrine of perception is summed up by himself as follows : — ' ^ All our intuition is nothing but the representa- tion, of phenomena ; the things which we intuite are not in themselves the same as our representations of them in intuition, nor are their relations in them- selves so constituted as they appear to us ; and if we take away the subject, or even only the subjective constitution of our senses in general, then not only the nature and relations of objects in space and time, but even space and time themselves disappear ; and these as phenomena cannot exist in themselves, but only in us. What may be the nature of objects considered as things-in-themselves, and without re- ference to the receptivity of our sensibility, is quite unknown to us. We know nothing more than our CHAP, III. SECT. VII. Summary of Kant's doctrine. 156 THE ELEMENTS OF THE CHAP. III. SECT. VII. Criticism. mode of perceiving them ; and with this alone we have to do. Space and time are the pure forms thereof; sensation the matter. The former alone can we cognise a priori, that is, antecedent to all actual perception ; and for this reason such cognition is called pure intuition. The latter is that in our cognition, which is called cognition a posteriori, that is, empirical intuition. TJie former appertain abso- lutely and necessarily to our'Sensibility, of whatsoever kind our sensations may b^ ; the latter may be of very diversified character. Su'pposing that we should carry our empirical intuition even to the very highest degree of clearness, we should not thereby advance one step nearer to a knowledge of the constitution of objects as things-in-themselves.^^ * § 83. One great merit which we must ascribe to Kant is the dismissal from his psychology of all accidental side questions, and the clear presentation of the fundamental problems which the psychologist endeavours to solve. The process of perception is reduced ultimately to a consciousness of sensations varied in character, but all agreeing in having, as a condition of their possibility, particular forms. Through these sensations there is made known the existence, although not the nature, of things-in- themselves.' The essential problems of every system of psychology must have reference to — (1) sensations, or what Kant calls the matter of sensations; (2) space and time, called the form of sensations ; and (3) the * These quotations from Kant's " Kritik " are from Mr. Meikle- john's translation, published in Bohn's series. PSYCHOLOGY OF COGNITION. 157 thing-in-itself, or whatever it may be called, sup- posed to exist independently and as the cause of sensations. There is a fourth problem not so funda- mental, regarding the process by which sensations form themselves or become transformed into distant objects of perception. Here we have presented in very small compass the subjects of all the disputed questions of psychology, and if psychologists only understood one another, the probability is that there would not appear so great a difference between their views as is now supposed. With regard to the first of these problems, the nature of the immediate objects of consciousness, Kant makes no distinction between the sensations and the mental acts which they constitute. But still they are mental, purely mental, and called by him representations of other and unknown objects of .iintuition. We shall have to notice in a subsequent )hilosopher an important difference regarding this [uestion. The cardinal doctrine of Kant's psycho- logy of perception is, however, the a ^priori and )henomenal character of space and time. Space and time are subjective in their origin, and are conditions only of phenomena, not of things-in- themselves. This problem also, we shall find,* gives rise to a great deal of discussion. An investigation into the nature of the so-called things-in- themselves is not properly a psychological one, although psy- chology has to do with the grounds of our belief in them. Kant considered them beyond the sphere §§ 88-90. CHAP. III. SECT. VII. Immediate oljects of conscious- ness. Space and Time. Things-in- them. selves. 158 THE ELEMENTS OF THE CHAP. III. SECT. VIII. Study of modern psycho- logy. of human knowledge, but Kant's German successors broke through the trammels which he had attempted to impose upon the human intellect, and speculated boldly regarding the nature of laws of what he pronounced unknown. Into these speculations it would be inconsistent with our subject to enter. But the psychological doctrines of Kant have been fruitful in stimulating and, to a certain extent, in guiding subsequent researches into the perennial problems of thought which he apprehended so clearly. Any criticism of Kant's doctrines we shall not now attempt, but leave it to be done by those of the present generation, to whom we must now devote some attention. Our historical review will, we trust, have produced two good effects : it will have enabled us to see the most important errors of the earlier psychologists ; and will have given us a clear appre- hension of what are the fundamental problems of the psychology of perception. Section YIII. modeen english psychology. § 84. Was Kant successful in his refutation of Hume ? By the principle which Kant endeavoured to establish, 'was philosophical scepticism rendered impossible or absurd ? For an answer to these and similar questions we must look to the history of modern psychology. Hume and Kant are the representatives of the two great schools of modern English psychology, and it shall be our task in this PSYCHOLOGY OF COGNITION: 159 closing section to refer, as briefly as possible, to tbe fundamental questions regarding wbicb tbese schools are at issue. It would be impossible, within the space to which we propose to confine ourselves, to give anything like a fair account of even the most important of the psychological works of the present time; it would be equally impossible to do justice to the philosophical ability and learning with which the great problems of psychology have been treated. All that we propose to do is to introduce the student to a sphere of research of great interest and great extent, and to furnish, perhaps, some stimulus and some guidance in the pursuit of knowledge. "We shall not, therefore, as heretofore, consider each psychological system by itself, but shall give an account of the manner in which psychological pro- blems and difficulties have been treated by different writers. For the sake of brevity, we shall endeavour to avoid everything of secondary importance and of merely historical interest. We shall restrict our- selves to the consideration of the few essentially important problems which must be solved in one way or another by every psychological system ; pro- blems which have already been pointed out in connection with Kant. The attempt to ascertain or accurately to state what a philosopher really means is frequently attended with considerable difficulty ; and we have prominent examples of the evils arising from a disingenuous or a prejudiced read- ing of the doctrines of another. This we shall endeavour to avoid, and give as briefly and accu- CHAP. III. SECT. VIII. Problems. i6o THE ELEMENTS OF THE CHAP. III. SECT. VIII. Objects of conscious- ness. rately as possible the doctrines which we propose to discuss. § 85. Kant^s general doctrine that there are certain a priori truths or principles which could not originate in experience may be better discussed at a future time. At present we are concerned chiefly with the modern doctrines concerning : — (i) Sensations, or the immediate objects of con- sciousness ; (2) space and time, especially the former; (3) the object and the process of percep- tion; and (4) the believed objective cause which may account for the existence and permanence of the objects we perceive. The question as to the nature of the immediate objects of consciousness is one of great importance. It has been almost universally held that the objects of which we are immediately conscious are ideas purely mental, either identical with the act of consciousness, or numerically, but not in nature, different from it. The names which have been given to these objects are various : sensations, impressions, ideas, repre- sentations, and so on. Whatever the name may be by which they are designated there has been a re- markable concurrence in considering the immediate objects of consciousness simply modifications or activities of the ego. Such is still the doctrine of those who adhere to the Berkeleyan idealism ; such is the doctrine of nearly all the Association-school of psychologists represented by Hartley and the two Mills. In opposition to this view we have the doctrine to the establishment of which Sir W. PSYGHOLOGY OF GOGNITION. i6l Hamilton devoted his learning and abilities, the doctrine that the immediate object of consciousness is not merely a mental product, but that it is the non- ego. There is frequently a great deal of difficulty in reconciling Hamilton with himself, and in getting a really intelligible view of his psychology. He frequently speaks as if distant and material things were objects of consciousness ; and as if the impres- sions made upon our organs of sense were objects of perception. But laying aside both of these erroneous and un- guarded statements, and interpreting him in a fair and candid spirit, it appears to us that the essential point of his doctrine as distinguished from that which we have before referred to is as follows : In conscious knowledge there is an ego and a non-ego, a subject and an object known in contrast to one another. The object is an affection of the sensorium, a sensation of some kind, say of colour, resistance, or sound. But although a sensation, it is or reveals a veritable non-ego in immediate contrast with the ego. Conscious knowledge is in fact impossible which does not set over an object against the subject; and in relation to perception that which is thus objectified is a sensation. Thus sensations, although immediately known in consciousness, are not there- fore purely mental ; they contain a foreign element j they belong to or constitute the non-ego of our immediate knowledge. ^^ § S^. This difference of view regarding the nature ^Bf the immediate objects of consciousness is a funda- CHAP. III. SECT, VIII. Associa- tional and intuitional schools. 1 62 THE ELEMENTS OF THE CHAP. III. SECT. VIII. mental distinction between wliat we may call the Associational and tlie Intuitional schools of psy- chology. It must be accepted as a fixed principle of association that nothing can appear in the result of the process of association which was not involved in the original elements.* Now, according to most of the members of the associational school the origi- nal elements to be associated are sensations in cer- tain relations. If these sensations are nothing but activities of the ego, if they are purely mental products, it is manifest that the objects into which these sensations are clustered and bound together by association can never become anything else but mental. If they are at the beginning, they must continue to be unto the end of the associational pro- cess, simply mental states or activities. And in the writings of the consistent association-psychologists, as Hume and J. S. Mill, we find that this is actually the case. Objects are clusters of sensations supposed to have a permanent existence independent of the individual mind, in consequence of their mutual co- herence and regular recurrence. They are mental products objectified, and called by Mr. Mill Per- manent Possibilities of Sensation. He has been censured for using such a negative term to indicate what other people think to be a collection of positive and non-mental powers. But the term is the very best he could have used. Beginning his associative process with purely mental elements, he could never * That is, nothing different in kind. We have seen that asso- ciation of sensations may give rise to new sensations, see § 25. FSYGEOLOGY OF COGNITION. 163 reach to that which, is non-mental. And if his psychology may be condemned because it does not recognise that which is essential in our knowledge of a material world, it cannot, at least, be condemned for its inconsistency. § 87. The other view, which we consider the correct one, regards sensations as being or involving subject i^lus object ; there is in consciousness given an ego and a non-ego; there is something in the object of consciousness other than a merely mental state or activity. The full significance of this we shall not attempt to bring out at present. But in the meantime, we can see that there is not the same difficulty in attaining to a knowledge of a veritable objective world as in the former case. We can see that the association of elements already containing a true non-ego could easily and consistently lead to the ultimate result of the perceptive process, the knowledge of objects constituting a real world. We may now advance to the consideration of another fundamental difference between the two psycho- logical schools. This difference has reference to the nature of our cognition of space or extension. § 88. Kant, in order to withstand the scepticism of Hume, gave to space and time an a priori origin as the native form of our sense-intuition. The con- ceptions of space and time are not derived from experience, but they are the conditions by which I experience is rendered possible. It is impossible to I perceive any object or quality except in space, and I his necessity at the very beginning of experience, M 2 CHAP. III. SECT. VIII. Intui- tional stand- point. Extensiony d priori theory. 164 THE ELEMENTS OF THE CHAP. III. SECT. VIII. Extension the result of associa- tion or ah- atraction. it is alleged, could not be the result of experience. The necessity, however, is a subjective one; space and time have only a phenomenal reality ; things in themselves do not exist under spatial and temporal conditions. Now, if by a priori, Kant meant only to oppose Hume^s maxim that all our knowledge consists of impressions or sensations, and ideas, which. are the copies of sensations, he appears to have suc- ceeded. That which is at first a necessary condition of intuition cannot itself be the product of sense-ex- perience. But the expression d priori appears to in- volve a view which modern psychologists are anxious to avoid. It appears to convey the idea that there is in the mind some hidden receptacle of unconscious forms or principles which are ready to start up into conscious life whenever the first incipient experience calls for them. This hidden limbo of d priori princi- ples which cannot be examined by the light of con- sciousness is most convenient for those psychologists who think that it is a sufficient explanation of all their beliefs, whether simple or complex, which they can- not get rid of. But it appears at first sight un- philosophical to attempt to explain a difficulty by a mystery ; to account for some necessity by assuming the antecedent existence of some form or principle in some hidden mental labyrinth beyond the ken of consciousness. § 89. Leaving for the present Kant's d priori ex- planation of space, we may examine the doctrines of more modern psychologists regarding it. These doctrines may be reduced to two. In the first place, PSYCHOLOGY OF COGNITION. I6S it is maintained that tlie idea of space is tlie product of some process of abstraction or association ex- ercised upon sensations; in tlie second place, it is keld tliat space is given in intuition. With reference to the first of these doctrines we have already examined* one form of it as held by J. S. Mill, and seen the impossibility of the attempt to evolve space from time. And if we consider for a moment the nature of the processes of association and abstraction, we shall see that neither of them can account for the origin of our knowledge of space. Association unites together sensations or other objects of in- tuition into a compound ; but the compound thus formed cannot possibly contain anything which was not in the original elements associated. Suppose that our only original intuitions are unextended sensa- tions and the relation between them of succession or time, it will be impossible for any association to convert either sensations or time, or any com- bination of the two, into space. The most elaborate attempt to do so is that of Mr. Mill, and it, we have seen, is a failure. Equally impossible it is for the process of abstraction to ijroduce anything not involved in the original objects of intuition, or in the perceived relation between them. Suppose that we are conscious of redness, greenness, blueness, and other particular sensations of colour. We are able to compare them, perceive their resemblances and differences, and form a general idea indicated by a general name, colour. Now in the result of this *§34. CHAP. III. SECT. VIII. 1 66 THE ELEMENTS OF THE CHAP, III. SECT. VIII. Extension, an intui- tion. process there is notliing contained whicli was not given in tlie original intuitions ; the result is just the summing up^ as it were, of the original intuitions of particular sensations and their relations. In this case abstraction is employed for the purpose of generalisation, for the formation of a general idea or name. But space is not a general name ; it is not predicable of any of the objects from which it is said to be produced by abstraction.* Nor is it in any way possible to know by abstraction /rom objects of consciousness what was not known by intuition in> them. Those who maintain the contrary have yet to show its possibility. § 90. The other modern view regarding the origin of our knowledge of space we have already expounded in Chapter II., and to that exposition now refer the reader. Extension, a form of space, is, we be- lieve, given in an intuition ; if not, we do not see how it can be known at all, as it certainly has hitherto proved incapable of resolution into any- thing else. At the same time, although the essential element of extension is given in intuition, it must be admitted that abstraction has something to do with the elabo- ration of our notion of space. Abstraction must be made from the particular sensations or qualities which are given in intuition as extended, and there remains the extension without the quality, the form without the matter. But this abstraction manifestly does not produce our idea of extension, it simply * See Spencer, "Psy.," ii., 352. PSYCHOLOGY OF COGNITION. 167 disentangles it from the sensation or quality in wliicli it is involved. With reference to the nature of space and time, there are many questions which have long exercised the minds of thinking men. Are they real things, having independent existence ; or are they only attri- butes ? Can we conceive empty space or time ; or are they always connected with sensible qualities or objects ? What is the nature of our conception of the whole of space and time; is it that of the infinite, or only of the indefinite ? A reference to the modern doctrines regarding these and other questions would compel us to exceed our limits, and we must therefore refer the student who wishes to pursue his inquiries farther to the many able works upon these subjects which have been produced in recent times.* § 91 . We must now give some attention to modern doctrines regarding the object and the process of perception. And we remark at the outset that it seems desirable for psychologists, when adopting words that are in common use, to give them as nearly as possible the meaning sanctioned by ordi- nary usage. The word perception, when used, by ordinary intelligent men, has a certain definite meaning and object ; it means the knowledge which we have of objects at a distance from us, believed to have an independent and permanent existence, whether they are perceived or not by us or any other sentient being. But psychologists have con- cluded, and rightly, that this knowledge is a very * e. g., Hodgson on ** Space and Time." CHAP. III. SECT. VIII. Perce'p- tion. i68 TEE ELEMENTS OF THE CHAP. III. SECT. VIII. Mr. MilVs explana- tion of a material world. complex product ; tliey have analysed it into wliat they have believed to be its simplest elements ; but instead of keeping the name perception to its proper object, the complex product, they have applied it to some of the more simple processes into which the complex has been analysed. And as it has not been applied uniformly, considerable confusion has been caused. We have next to refer to a false distinction be- tween two opposing psychological' schools. One school has been called the associational school, another the intuitive. The distinction is not an accurate one. All . psychologists agree that the object of perception, as we understand and have just explained that object, is not intuitively known. All psychologists must assume at the beginning of the construction of their acquired knowledge certain objects which are intuitively known. All psycho- logists make some use of the principle of association in explaining the construction of their knowledge. The only important differences which exist between psychologists have reference — (1) to the number and kind of the objects of intuitive know- ledge; (2) to the extent of the use which may be made of the principle of association ; and (3) to the question whether association can explain everything, or whether some other principle must be called in. § 92. Mr. Mill, who is the representative of a large class of psychologists, past as well as present, assumes as the original contents of intuitive know- ledge, certain sensations or states of consciousness. PSYCHOLOGY OF COGNITION. 169 and the relations of co-existence and sequence exist- ing between them. Upon these original intuitions he sets at work with his laws of association, and attempts to explain our belief of the external world. We have already seen with what success he has attempted to account for the origin of our idea of extension or space. We must now examine his attempt to explain our knowledge or belief of a permanent material world. Beginning with the existence of sensations, he maintains* "that there are associations naturally, and even necessarily, generated by the order of our sen- sations and of our reminiscences of sensations, which, supposing no intuition of an external world to have existed in consciousness, would inevitably generate the belief, and would cause it to be regarded as an intuition.''^ In support of this he shows that, in certain circumstances, sensations which we have felt recur to us regularly upon the fulfilment of certain conditions ; that thus we think of the possibility of the recurrence of these sensations as being per- manent, whereas sensations themselves are fugitive ; that it is not merely single sensations, but groups of sensations, which are thus connected with permanent possibilities of them ; and that the sensations of these groups occur in a certain fixed order. " Hence,^' he concludes, " we speedily learn to think of Nature as made up solely of these groups of possibilities, and the active force in Nature as manifested in the modification of some of these by others. The sensa- * " Examin.," p. 221. CHAP. III. SECT. VIII. I/O TEE ELEMENTS OF THE CHAP. III. SECT. VIII. Criticism. tionSj tliougli the original foundation of the whole, come to be looked upon as a sort of accident depend- ing on us, and the possibilities as much more real than the actual sensations, nay, as the very realities of which these are only the representations, appear- ances, or effects. When this state of mind has been arrived at, then, and from that time forward, we are never conscious of a present sensation without in- stantaneously referring it to some one of the groups of possibilities into which a sensation of that parti- cular description enters ; and if we do not yet know to what group to refer it, we at least feel an irre- sistible conviction that it must belong to some group or other, i.e., that its presence proves the existence, here and now, of a great number and variety of pos- sibilities of sensation, without which it would not have been. The whole set of sensations as possible, form a permanent background to any one or more of them that are, at a given moment, actual; and the possibilities are conceived as standing to the actual sensations in the relation of a cause to its effects, or of canvas to the figures painted on it, or of a root to the trunk, leaves, and flowers, or of a substratum to that which is spread over it, or, in transcendental language, of Matter to Form.'^ * Here, then, we have the external world produced by Mr. Mill from sensations variously associated together. § 93. Now, let us pass over the question, how Mr. Mill gets his sensations projected into space, *"Exainm.," p. 224-5. PSYCEOLOGY OF COGNITION. 171 whicli he does not explain, and refer to another point of more vital importance. He speaks of " the active force in Kature," but we may ask how he comes to know anything about such a force ? Force is not a sensation, nor is it any association of sensa- tions. This, however, is not the main point of our criticism. '^ The whole set of sensations," he says, " as possible, form a permanent background to any one or more of them that are, at a given moment, actual ; and the possibilities are conceived as stand- ing to the actual sensations in the relation of a cause to its effects." Let us examine this statement. The possibility of sensations is conceived as the cause of actual sensations. We have, for example, the sensation of a particular figured colour which is associated with the name orange. Connected with this sensation there are a number of possible sensa- tions of smell, taste, touch, sound, &c. The possibility of those sensations is the cause of the colour. What does this mean? Is the possibility of a smell the cause of a colour ? Is the possibility of a taste the cause of a colour ? Or is the possibility of all the other sensations of the group taken together the cause of colour ? If we ask a scientific man what is the cause of colour, he will answer that it is a ray of light. If we inquire farther what he means by a ray of light, he will tell us that it is the insensible vibration of an ethereal fluid caused by some power of a luminous body. This we can understand, but when Mr. Mill tells us that the possibility of a smell, or a taste, or a touch, or all put together, is the CHAP. III. SECT. YIII. 1/2 TEE ELEMENTS OF TEE CHAP. III. SECT. VIII. Mr. Mill's method criticised. cause of a colour, we confess that we do not under- stand what he means. There appears to be such an utter incongruity between the antecedent and the consequent, that we cannot think of them as form- ing a sequence. And what is true of the sensation of colour, is equally true with reference to all our other sensations. The possibility, as Mr. Mill calls it, of one or more sensations of a group, we cannot think of as being the cause of the remaining different sensation or sensations. But yet this is the only kind of cause which could be reached from the original elements with which he sets out by the help of association. He begins with sensations ; he ends with groups of actual and possible sensations having a fictitious objectivity. § 94. If, then, Mr. Mill's laws of association operating upon the original sensations of conscious- ness do not produce what we believe to be a veri- table external world, we have now to inquire whether there is in his method any fundamental defect. The result of this inquiry will simply be an answer to the question formerly referred to, — Whether some other principle than the laws of association be not necessary to explain our belief in an external world? We believe that there is; and that the essential defect of the psychology of which Mr. Mill is an exponent, consists in the ignoring of this other principle. In that psychology it is assumed that sensations exist ; but no attempt is made to account for their existence. Sensations exist in certain relations of co-existence and sequence; in some PSYCEOLOGY OF COGNITION. 173 cases an invariable relation of antecedence and consequence is observed; and by association tlie antecedent conies to be looked upon as tbe cause of tlie consequent. And from this association or phenomenal theory of causation we are led to the absurd conclusion that the possibility of a sensation of resistance or smell is the cause of an actual sen- sation of colour. Now, it is perhaps in the simple original sensations of our consciousness that we are able to see most clearly the fallacy of the phenomenal view of causation which Mr. Mill accepts. When we have a sensation, say of smell, or colour, or taste, although they are most intimately and inseparably associated together, we never look upon the one as the cause of the other. And yet we do give an account to ourselves of the cause of these sensations. They are something beyond our own control ; they come to us unbidden ; and our very powerlessness with reference to them compels us to refer them to some objective 'power. That power is, as far as our consciousness is concerned, unknown; it is not a phenomenoiij although it is manifested to us in a phenomenon. Thus our conception of a sensation as being a non-ego involves a belief of some veritable objective cause of it ; and this intui- tion of the causal relation, whether strictly original or not, must be carried with us through the whole subsequent process by which our perceptive know- ledge is built up. By the introduction of the causal judgment at this early stage we are able to account for the objectifying of our sensations; and we are able CHAP. III. SECT. VIII. 174 TEE ELEMENTS OF THE CHAP. III. SECT. VIII. Inferred causes of pheno- mena. to account for a. belief in material body in which, will not be involved the absurdity of one sensation, or the possibility of one sensation being the cause of another of a different kind. According to this view, phenomenal body consists of objectified sensa- tions collected together in a group by association ; but to this body the educated intellect does not attribute any causal efficiency. On the other hand, non-pTienomenal body or matter, as it is called, is simply a synthesis of inferred powers, each power being inferred to account for the sensation or quality corresponding to it which enters as a constituent member into the group of qualities which we perceive. § 95. The statement of this latter view regarding the nature of the perceptive process in which the principle of causation is made use of in addition to the laws of association brings us to the last important point which we proposed to consider. The nature of the inferred causes of our sensations and their synthesis is a problem which the phenomenalism of Mill and his school does not touch. And yet it is with this problem that a great deal of modern science has to do. Light, heat, electricity, force, as studied by physicists, are non-phenomenal powers, and the object of science is to ascertain their laws and relations. With this subject we have nothing to do, except to point out that a true psychology must leave a place for it. The only place which Mr. Mill, leaves for physical science is in that nega- tive, utterly tantalising shadow of a thing which he PSYCHOLOGY OF COGNITION. 175 calls tlie permanent possibility of sensations. Ideal- ism postulates an intelligent power as tlie cause of the existence and objective synthesis of sensations; and to this there is perhaps no serious objection, except that the language which is used frequently leads ordinary people to suppose that something very absurd is meant. Realism, as found in Herbert Spencer and the Scottish school of philosophers, demands a belief in real objective non-phenomenal forces, capable of correlation with and transmuta- tion into one another. Into a discussion of this we cannot enter ; sufficient that we have pointed out its relation to the legitimate subjects of psychology. We must now close our discussion of modern theories of perception, although aware of many im- portant omissions and imperfections in our sketch. The necessity for brevity must be in part our apology for these. The student who wishes to pursue the subject farther will find valuable as- sistance in the works of Hamilton, Ferrier, Pro- fessor Grote, Bain, Mill, Spencer, Hodgson, Lewes and others. CHAP. III. SECT. viir. 176 TEE ELEMENTS OF THE CHAP. IV. SECT. I. Subject in- troduced. CHAPTER IV. BEFBESENTATION. Section I. CONDrriON OP eepeesentation. § 96. We jbave already seen that in the process of the acquisition of presentative knowledge there is found mixed up with it a great deal of what is only representative. Our perception of any external object is a complex of presentative and representative elements^ of actual and ideal sensations. Thus^ in the acquisition of knowledge, there is involved the possibility of representing the elements of the know- ledge already acquired. This power of representation is of great importance, apart altogether from its being subsidiary to the perceptive process, so that we must devote special attention to it. By far the greatest part of our knowledge can be brought before con- sciousness only in a represented state ; and all the higher operations of the mind depend upon represen- tation as a condition of their possibility. Before entering upon a consideration of the laws and kinds of representative knowledge, we must first give heed to the question, — How is representation possible ? What are the conditions upon which the representing PSYCHOLOGY OF COGNITION. i;7 in consciousness of forgotten knowledge depends ? Sensations, once felt, disappear from consciousness ; knowledge once obtained, whetker very simple or very complex, drops into oblivion. After a long time tke sensation may be more or less vividly revived, tke knowledge more or less completely restored. In tke interval, it kas been completely out of tke spkere of consciousness. In its represented state, its original cause, tke object of presentative knowledge is not present. Tke question is, — How is tke knowledge revived witkout tke assistance of its original object ? How is tke sensation repeated witkout tke concurrence of its original external cause ? As tke objective cause of tke recurrence of actual sensations in regular groups and order kas been called tke permanent possibility of sensations, so we migkt kere speak, and witk better reason, of tke permanent possibility of pkantasms or ideas as being tke condition of represented knowledge. But tke trutk is tkat, in botk cases, tke permanent possibility is tke very fact to be explained, and tke mere statement of tke fact is not tke explanation of it. Tke general fact, tken, wkick we know regarding tkis subject, is tke permanent possibility of becoming conscious of pkantasms or revived sensations. § 97. Tke explanation of tkis fact is a problem of very considerable difficulty. Tkere is no extra- organic object necessary to aid in tke recall of for- gotten knowledge. Sensations and perceptions, wken forgotten, are altogetker beyond tke ken of con- sciousness. Tkere are, tkerefore, no direct means of CHAP. IV. SECT, I. Explana- tion hypo- thetical. 178 TEE JEJLB31ENTS OF TEE CHAP. IV. SECT. I. Two hypo- theses. Mental la- tency. observing tlie condition of the possibility of their recall. Consequently, as far as psychology is con- cerned, the explanation must be hypothetical. The hypotheses which have been proposed in explanation of the problem are two in number. The condition of the permanent possibility of phantasms may be mental, or it may be organic ; in the former case, we have the hypothesis of latent mental modification ; in the latter, that of unconscious cerebration. To the respective claims and difficulties of these two conflicting hypotheses we may give some attention. § 98. The doctrine of latent mental modifications has been already referred to* as an attempt to analyse sensations into unconscious elements, and in that connection we saw reason to reject it. As an expla- nation of the permanent possibility of phantasms or ideas, it is open to some of the same objections as before. It postulates that the mind is capable of retaining within itself certain latent activities which are lying ready to spring up into conscious life when- ever the occasion requires. But we have already noticed the objection against calling anything mental which cannot be observed by consciousness. If, how- ever, we admitted the theory of idealism to be true, this objection would fall to the ground. That theory explains the actual sensations which are the elements of perception as the result of an objective mental cause. And consequently it would have no objection to explain the permanent possibility of revived sensa- tions by a mental cause. But if we wish to retain * § 26. PSYCHOLOGY OF COGNITION. 179 the distinction between activities whicli are mental and powers whicli are not mental^ and if we explain the latter as powers which originate and operate beyond the sphere of consciousness^ we must reject the doctrine of mental latency. This distinction and explanation which characterise philosophical dualism as opposed to idealism appear to us to correspond to the truth of things^ and therefore we must seek elsewhere for an explanation of the per- manent possibility of phantasms and ideas. § 99. The mental hypothesis being rejected^ the only other possible hypothesis must refer us to some non-mental explanation of the difficulty; unless^ indeed, we take refuge in some supernatural ex- planation of it^ which, however, would in the pre- sent day scarcely be thought scientific. And as all realists or dualists admit a physical cause for their actual sensations, they can consistently offer no objections to the explanation of revived sensations by a non-mental cause. But as ex hypothesi there is no extra-organic object; the non-mental cause, if such there be, must be an organic one. The examination of this hypothesis is therefore trans- ferred from the hands of the psychologist to those of the physiologist, and the latter presents us with his theory of unconscious cerebration. In this hypothesis it is assumed that every sensa- tion which has come into consciousness has been preceded and caused by some molecular movement in the substance of the brain; it is assumed that the repetition or continuance of a cerebral activity N 2 CHAP. IV. SECT. I. Cerebral hypo- thesis. i8o THE ELEMENTS OF THE CHAP. IV. SECT. I. Difficulties occasioned by continued attention to tlie conscious feeling of which it is the antecedent, will have the effect of making a permanent change upon the nervous tissue, and thus of registering, as it were, the original activity, so that it may be easily re- peated. It is assumed, farther, that in the complex network of nervous centres which constitute the cerebrum, there is such a connection that any ac- tivity propagates itself from one centre to another, and to many others, and that this cerebral activity may either excite conscious sensations or not, according to circumstances. Here, then, we have all the essential elements of the hypothesis. There are, in the nervous tissue of the cerebrum, per- manent registrations of forgotten feelings; per- manent nerve-cells or clusters of cells produced or modified by some past activity ; and these explain the permanent possibility of forgotten sensations being revived. Into the details of the hypothesis we cannot at present enter, but offer the following remarks regarding its difficulties and advantages.* § 100. There is no possibility of observing directly the correspondence between conscious sensations and nervous activity. Neither is there any possibility of observing any changes which may take place in the nervous tissues of the cerebrum; and if there were, it could not be said that these changes are the result of sentient * Those who wish to pursue the subject further are referred to the writings of Herbert Spencer, Dr. W. B. Carpenter, and Prof. Bain. PSYCHOLOGY OF COGNITION. I8l activity. The evidence upon which the hypothesis is built is of a very indirect and obscure kind, consisting of facts observed by the vivisection of inferior animals, facts connected with diseased con- ditions of the human brain, and a variety of facts connected with peculiarities of memory and imagina- tion. Thus the hypothesis is connected with many difficulties and obscure problems which cannot as yet be said to be finally solved. These difficulties, however, should not lead to the rejection of the hypothesis. The law of gravitation, which is now so universally accepted, was originally only an hypothesis founded upon very indirect evidence, and relating to bodies apparently so remotely con- nected with one another, that a man of ordinary intelligence in the days of Newton would probably have thought it absurd. Nearly all the great laws of the operation of physical forces have been slowly and laboriously established by the skilful guesses of men of genius being applied to the explanation of observed facts. The impossibility of directly observ- ing unconscious cerebration, or cerebration of any kind, therefore, ought not to be conclasive against the acceptance of the hypothesis ; and yet more, if this hypothesis be entertained, there is room for further discovery, whereas in the mental hypothesis there is none. What is beyond the reach of con- sciousness the psychologist, as sach, can never examine. But the method and the skill of the physiologist are likely to improve as time goes on ; and consequently we may hope that much additional CHAP. IV. SECT. I. Should not cause re- jection of hypo- thesis. l82 THE ELEMENTS OF TEE CHAP. IV. SECT. II. light may in future be thrown upon the obscure problems concerning the condifcions of mental activity. In the meantime we have nothing more than an hypothesis; but no psychologist who is uninfluenced by prejudice will deprecate the time when the hypothesis may be recognised as an established law. Section II. LAWS OF EEPEESENTATION. § 101. Everyone is familiar with that condition of mind which we call reverie. In moments of quiet repose, when there is nothing to agitate or disturb us, there appear before consciousness numberless and varied images of sights and sounds, of persons and things, of places and periods of life, of feelings and thoughts, of events long since past, of possible events still to come. These phantasms come and go apparently altogether independent of any effort on our part — they are spontaneous. But at other times when we have some object to accomplish, something to call forth our activity, we are able to control the representations of the fancy, to banish certain phantasms from consciousness and to call up others, to give attent'ion to some and to disregard others. In this case the representation of phantasms is under the control of our will — it is voluntary » Now, in the study of the spontaneous and voluntary representa- tions of the mind, the first problem which presents itself to the psychologist is to determine the laws PSYOEOLOGY OF COGNITION. 183 according to which phantasms either spontaneously appear or, by an effort of will, are made to appear before consciousness. And here it must be observed that there is liability of confusion from not adhering closely to the problem to be solved. The word laiu should here indicate a general statement of the order or relations observed amongst the facts given ; whereas it has been taken to mean an exposition of the nature or mode of operation of the cause by which the facts are supposed to be produced. Adopt- ing the former sense, we proceed to state the laws of representation which have been formulated by psychologists under the name of laws of association. § 102. The special laws of association which have been laid down are usually stated to be seven in number : co-existence or consecutionin time; contiguity in space ; dependence as cause and effect, means and endj whole and part; resemblance or contrast; pro- duced by the same power j or conversant about the same object ; signified and signifying ; designated by the same sound. Illustrations of the connection between ideas thus related to one another will readily occur to every one, but the following may be taken as examples : — In perception those sensations which are usually felt together or in immediate succession have a bond of association formed between them. Hence, an actual sensation which has previously been felt at the same time as a number of other actual sensations, when it is again experienced, brings along with it the phantasms or ideas of the other possible sensations CHAP. IV. SECT. II. Meaning of laivs. Laws stated, Illus- trated, 1 84 TEE ELEMENTS OF THE CHAP. IV. SECT. II. of the group. So in more complex experience, per- sons and places and events whicli have been once conjoined together in our knowledge are always likely to be thought of together at subsequent times. From the process of perception also many illus- trations of the influence of contiguity in space in forming associated groups might be drawn. In truth, co-existence in time and contiguity in space are usually combined together ; those objects which we have known at the same time have usually been close together in space, and both might be combined under one relation, that of contiguity in general. In the next law, that of dependence, as of an effect upon its cause, an end upon its means, we have also a kind of contiguity. If we take the phenomenal view of causation, considering the cause of one phenomenon to be an immediately preceding phe- nomenon, this law may be completely reduced to the preceding one of contiguity in time and place. We say, for example, that fire is the cause of heat. If this means that the bright-coloured flame which we see is the cause of the sensation of heat which we feel, there is in the relation nothing but contiguity. But if it means that there is some real objective force which is at once the cause of the flame which we see and of the heat which we feel, there is some- thing more in the connection between a coloured flame and a feeling of heat than mere contiguity in time and place. Thus the possibility of reducing the causal relation to one of contiguity depends upon the view of the nature of the causal relation PSYCHOLOGY OF COGNITION: 185 which we take. If it is only a relation between phe- nomena, it is nothing but a special form of the law of contiguity in which an antecedent phenomenon called a cause is joined in our thoughts with a consequent phenomenon called an effect. If it is a relation believed to exist between that which is a phenomenon and that which is not a phenomenou, although the former is always associated with the latter, the connection of the two in thought exists, not because of frequent experience, but because of being given in an original or very primitive inference. As this latter is the view which we have maintained,* we cannot reduce the causal relation to that of contiguity. The relations of similarity and contrast have a very powerful effect in recalling previous objects of in- tuition to the mind. A single sensation of any kind leads us to think of any similar sensation of the same sense which we have previously experienced. So a whole complex of sensations which we have formed into an object leads us to think of other similar objects. Illustrations of this are so numerous and familiar that we need not specify. So when simi- larity is made conspicuous by its absence, that is, when objects are strikingly in contrast with one another, the one has a strong tendency to recall the other. The other relations, of things produced by the same power or conversant about the same object, of signified and signifying, of things designated by the * See § 94. CHAP. IV. SECT. II. 1 86 THE ELEMENTS OF THE CHAP. IV. SECT, II. Reduced to more gene- ral laws. Redinte- gration. Integra- tion. same sound, are so obviously reducible to one or other of tlie preceding tbat we need not give to tbem special attention. In addition to tbose whicli have been mentioned there are many other special relations which may form a ground of association ; but probably there are none which might not be reduced to one or other of the three important rela- tions to which we have referred — those of contiguity, causation, and similarity. § 103. Various attempts have been made by philo- sophers to reduce those special relations which form the basis of association into more general laws. Prof. Bain reduces them to two, the Laws of Con- tiguity and Similarity, Hamilton and others to the Laws of Simultaneity and Affinity. A still higher generalisation reduces these all to one, that of Eed- integration, first enounced by Augustine, and after- wards adopted by many subsequent philosophers. It is thus stated : objects that have been previously united as parts of a single mental state tend to recall or suggest one another. This, however, is so ob- viously open to the objection that it does not account for the formation of new associations never before perceived, that it has been modified into what has been called the Law of Integration, "which may be defined as that whereby the mind, in all its efforts, completes a circle of thought — in other words, brings a whole into all its representations. If we suppose, for example, the case of one face, from some point of likeness in it, suggesting another, let us see what is the mental process which takes place. The mind, on PSYCHOLOGY OF COGNITION. 187 apprehending the particular point of resemblance in the face before it, immediately begins to complete the image thereby recalled. It feels that it has got a part of a whole formerly familiar to it, and its immediate aim is to bring into view that whole. In ordinary instances the image completes itself in- stantaneously, and we are not therefore conscious of any such aim ; but in some instances, it is only after frequent efforts that it does so (as when we see a face resembling one that we cannot yet recall), and then we become distinctly conscious of the reproductive operation. The eye, or mouth, or whatever part of the strange face is recognised as familiar, is fixed upon by the mind, and becomes the centre of a representative picture in which the mind has no satisfaction till it is completed. In the case of the law of contrast, as when night suggests day, good evil, a dwarf a giant, the mental process is still more obviously of this integrating character. For, in fact, the one mental conception here directly involves the other, and is only fully intelligible in relation to it. Each idea is to us only what it is on account of its opposite. In passing from the one to the other, therefore, the mind is simply completing the complex image, one side of which is always the necessary correlate of the other. The same seems to hold equally true of the law of co-adjacency, as when a certain house recalls the friends we met — the conversation we had in it ; or when one event recalls another which had happened at the same time In speaking thus of the pro- cess of reproduction as throughout of an integrating CHAP. IV. SECT. II. TEE ELEMENTS OF TEE CHAP. IV, SECT. II. character, it may be necessary to guard against our being supposed to say tbat tlie mind necessarily impresses a whole upon all the successive train o£ its ideas. This, on the contrary, we know it frequently does not do, the last link in the train having often no relation to the first as parts of a common whole. Mental succession is not unfrequently, as in reverie, a mere straggling array of scattered images. The integration does not proceed, as it is not necessary that it should, all along its course, but only from step to step. The general train may thus present a very incongruous mixture of ideas, while it has yet, at every step, strictly obeyed the great law of mental development. We may further observe that it is not necessary, as we might be apt to think from a first confused conception of the law, that the facts of a train of association should have previously co-existed in the mind. In some cases they have co-existed, and to this fact of their co-existence is owing their tendency to reproduce one another ; but more frequently they have had no such previous alliance in the mind. An object never before perceived may suggest an old familiar object; while again, an object frequently perceived may suggest, in different moments, very different and even quite opposite trains of thought. Were it not for this characteristic of the principle of association, the field of our knowledge would have been comparatively narrow, confined, as it must have been, to the relations which from actual obser- vation, we had stored up in our minds. We would PSYCHOLOGY OF COGNITION. never have been able to get out of the past wheel or circle of our thoughts. As it is, the suggestive capacity, continually started by everything around us, is, in all active and cultivated minds, ever entering on fresh fields of intellectual interest, and acquiring fresh stores of knowledge/^ * Section III. KINDS OF EEPRESENTATION. § 104. The simplest mode in which the repre- sentative faculty operates is illustrated in reverie. Objects are presented before consciousness singly or in groups, without any particular order and without any connection with a place or a time in which they have previously been known. This mode of repre- sentation, in which phantasms are isolated from their determining circumstances, has been called phantasy. Dreaming is a well-known example of it. Images come spontaneously into the mind, and are supposed to have a present reality. These images may be complete in themselves, but they are separated from the various relations in which they may have been previously observed. This phantasy, this simple bare representation of images, is the least complex, and, at the same time, the least perfect mode of representation. It usually takes place in a state of mental inactivity, as in reverie or dreaming, when there is no voluntary putting forth of effort, or in some abnormal condition, as fever or * Tulloch's " Theism," pp. 211-14. CHAP. rv. SECT. III. Plumtasy. 190 TEE ELEMENTS OF TEE CHAP. IV. SECT. III. Memory. insanity, when the images of a period long past come up vividly before consciousness, although perhaps for years they had been dormant. Thus in simple phantasy the mind appears to be, to a great extent, passive ; there is no voluntary effort to fill u]p the circle of knowledge connected with any particular phantasm. Since this imperfect mode of representation is usually found in quiescent, abnormal, or diseased conditions of the organism^ physiologists have given great attention to it for the purpose of discovering the organic conditions upon which the power of representation depends. As, however, we are not at present interested in this question, we shall proceed to the consideration of a more perfect mode of representation, and one with which we are more familiar. § 105. Memory is not the simple representation of phantasms or images before consciousness ; it involves that, and something besides ; the additional elements which it involves appear to be the following : (1.) There must be Recognition; that is, the image at present before the mind is known to be the same, although numerically different, as one previously known. When we see the face of a friend whom 'we have not seen for a long time before, we recognise him, that is, we know that we have seen him before ; and in the same way when an image of an absent friend presents itself to the mind, we recognise it. (2.) Memory necessarily involves the element of PSYCHOLOGY OF COGNITION. 191 time. The very nature of recognition implies tliat the present act of the mind has a reference to some past time, and that the object recognised is believed to have been previously known. Although there may be many other circumstances connected with an act of memory, yet these three which we have mentioned — the simple phantasm, the recognition, and the reference to a past time — appear to be all the elements which are essential to memory. § 106. Memory, as a form of representation, we have seen to be essentially an integrating process. Some image presents itself before the mind, and we recognise it, that is, we believe that we have known it before in connection with a number of other mental objects. The act of memory is not complete until we are able to recall the other circumstances with which the recognised phantasm was originally connected in our knowledge. To remember a thing, in short, is to posit the image of the thing in the midst of a greater or less number and variety of other images in connection with which we have already known it. We must be able to posit it in time, but as time is known to us only by a succes- sion of events or images, the giving of a position in time to the object of memory implies an ability to say what events preceded, co-existed with, and succeeded it. Hence, when we try to remember an event, we are satisfied when we are able to say that it occurred about the same time or soon after another event with which we are more familiar. CHAP. IV, SECT. III. Memory of events in time. 192 THE ELEMENTS OF THE CHAP, IV. SECT. III. Scientific memwy without time. And tlie greater the number of tlie circumstances or events in tlie midst of whicli we are able to posit the object of memory, the more complete is the act of memory. These accompanying circumstances may be of any kind; may be sensations of our own minds, actions performed by us or others, objects existing in space, even arbitrary artificial signs indicating time, place, or circumstances. § 107. There are, however, forms of memory in which the reference to time does not appear to be essential. A student wishes to demonstrate the forty-seventh proposition of the First Book of Euclid; but he has partially forgotten it. He does not attempt to connect his partial knowledge with anything past. He looks at the figure and endeavours to recall the relations which exist be- tween the different parts of which it is composed. And a perfect memory of this proposition has pro- bably no reference to past time at all, but is simply a representation of the lines and angles of the figure before the mind, with a clear perception of the relations existing between them, and of the conclusion which follows from the comparison of these relations. Similar remarks might be made with reference to our memory of other systems of knowledge. . There is also a form of memory which is involved in the acquisition of practical habits, from which the element of time appears to be eliminated. When a musician remembers a piece of music, it is not meant merely that the musical notes are represented PSYCHOLOGY OF COGNITIOK. 193 before the mind's eye in their proper order, but also that he can, without hesitation or difficulty, strike with his fingers upon the proper keys, and produce in quick succession the sounds indicated by the musical characters. And, in this case, the want of memory consists in an inability to think of the par- ticular series of musical notes which should follow or precede some other remembered parts of the piece. Thus, perhaps, it would be more accurate to con- sider recognition as the one essential characteristic of memory by which it is distinguished from simple representation ; and to add that when the object of memory is a past event in our own lives, the act of memory involves also the positing of its object amongst a greater or less number of other objects or events related to one another in a past time. § 108. There is another mode of representation differing from simple phantasy in having a reference to time, and differing from memory in referring to future instead of to past time. This we call expec- tation or prevision. In the process of perception this plays a very important part. The different qua- lities of which an object of perception is composed have been so constantly found in our experience united together, that when we perceive any one of them we expect to find the others. We have always found that the coloured globular body which we call an orange contains within it a pleasant acid juice and several seeds. Whenever we see an orange we expect to find within it what our past experience o CHAP. IV. SECT. irr. Expecta- tion. 194 TEE ELEMENTS OF TRE CHAP. IV. SECT. IIT. tells us is likely to be there. Thus, expectation is founded upon memory ; and, upon the constancy and invariability of the experience with which memory furnishes ns will depend the confidence of our expectation. The perfection of expectation is prevision. The astronomer can predict with certainty when an eclipse of the moon will take place, because his calculations are founded upon a long series of accurately-observed and constantly and invariably- recurring phenomena. The weather-casts of the meteorologist do not give rise to the confident ex- pectation produced by scientific prevision, because the phenomena observed are exceedingly variable and inconstant, and it is known that there may be innumerable disturbing causes at work. In daily life the principle of expectation is of the greatest practi- cal importance in guiding our conduct. One of the forms of superstition consists simply in founding an expectation upon some sign or omen which is con- nected by tradition with the event expected. The slightest reflection might show the utter want of connection between the sign and the object of expec- tation; but the association has been formed in child- hood through the instructions of parents or relatives, and even after reflection has shown that it does not conform to truth or reality, its power can scarcely ever be completely overcome. A reasonable expec- tation is founded upon the remembered or well- attested experience of ourselves or others. We be- come acquainted, for example, with persons, and have opportunities of observing how they speak or act in FSYGHOLOGY OF COGNITION. 195 particular circumstances. We form an estimate of their character, that is, we construct in our minds a certain kind or class of ideal actions which we expect them to perform in certain circumstances. The better we know them, the greater confidence have we in our expectations. Thus, in all the circumstances of life, expectation, reasonable or unreasonable, is an important guide of our actions ; and our success in life to a great extent depends upon the carefulness and ability with which our expectations are formed.* Section IY. kinds of representation — continued ; imagination. § 109. The power possessed by the human mind of representation is exhibited in a still more import- ant form than any which we have yet considered. Hitherto we have studied the representing power in its simpler operations, in simply recalling in their natural order the objects of our previous knowledge. We have now to study the power of representation as combined with various other powers and exerted in various interests. And in this form of the operation of the representing power, we shall see that the objects represented are modified and rearranged in various ways to suit the design of the individual. This form of representation is usually called the * Although the most essential element of expectation is a mental representation referred to a future time, yet it is in reality founded upon inference, or a kind of implicit inference. 2 CHAP. ^^ SECT. IY. Represen- tation com" lined with other poivers. 196 THE ELEMENTS OF THE CHAP. IV. SECT. IV. Modifica- tions of mental pheno- mena caused hy imagina- tion. constructive or plastic imagination, to distinguish it from the simple representation of objects in phantasy and memory. Before proceeding to consider the most important special applications of the imagina- tion, we may refer to certain general principles of its operation. § 110. The following are the most important modes in which the constructive imagination is found to operate : — (1.) In imagination there may be a separation of the parts or qualities of which any object is made up. We can imagine a horse without its head ; a flower without its colour or smell ; a bird without its wings ; a human being without some quality or character which he now possesses. (2.) In imagination, parts or qualities thus separated from their natural relations may be re- combined so as to form new objects. Centaurs, winged bulls, griflB.ns, &c., are illustrations of this process. (3.) In this reconstructive process, the elements of the new object may be greatly and variously modified, may be changed in shape, size, or excellence, either for improvement or deterioration. Conformity to the truth of nature is not at all an essential feature of the products of imagination. (4.) In imagination, when we wish to represent to ourselves something unknown, we can do so only by employing elements taken from things known. We are frequently bound to believe in the existence of things which we have not directly known, and PSYCHOLOGY OF COGNITION. 197 probably can never know. In this case tlie imagi- nation clothes tlie unknown with forms taken from tbe known. (5.) In the object which the imagination constructs there must be a certain congruity between the elements of which it is made up in order to render the imaginative act possible. To imagine a square circle, for example, would be impossible. § 111. We shall now study the operations of the imagination as they are found in the most important departments of human mental activity, — in science, in art, in ethics, and in religion. It may perhaps be thought somewhat incongruous to unite imagination with science, as science is usually supposed to deal only with known facts. But the truth is that nearly all the great discoveries of science have been the result of an effort of imagination ; and many of the greatest men who have advanced scientific knowledge have been men gifted with a strong constructive imagination. Let us study the part which imagina- tion plays in the progress of scientific discovery. Some phenomenon, say the fall of rain from the clouds, requires to be explained. It is observed that dark clouds appear in the sky; the lightning flashes, the thunder rolls ; the rain falls down in torrents; the cause of all this is unknown, and people set their imagination to work to think of what the cause may be. In other words they frame an hypothesis. Now in all cases, the nature of the hypothesis framed will depend upon the nature and amount of the knowledge or belief possessed by the CHAP. IV. SECT. IV. Imagina- tion in science illus- trated. 198 TEE ULmiENTS OF THE CHAP. lY. SECT. IV. Further described. persons who frame it. The uneducated Hindu peasant sees the dreadful commotion in the skies, and imagines that the elephant of Indra is up there throwing down the water which he has taken from the sea with his trunk. If any difficulty presents itself, it will soon be got over by the reflection that Indra is great and can do all things. This is an illustration of a very primitive kind of hypothesis framed for the explanation of phenomena. But as men advance, they observe more closely the phe- nomena of nature. Vapour is frequently seen rising from the surface of water ; especially when heat is applied this takes place. At length some genius, by an effort of imagination, sees the analogy between the formation of clouds in the heavens and the accumulation of steam in a room in which there is heated water. This observation is a hint which may assist in the formation of a new hypothesis. One hint after another of a similar kind is taken advan- tage of, until everything connected with the thunder- storm is found to be analogous to some well-known natural operation. Then the mind is satisfied and the hypothesis becomes a theory. § 112. The foregoing is an illustration of the manner in which nearly all the most important scientific discoVeries have been made. Some great series of natural phenomena requires an explanation. Its cause is unknown, or people are dissatisfied with the explanation hitherto given. The imagination of some Newton is brought to bear upon the problem. His genius enables him to imagine that the unknown PSYCHOLOGY OF COGNITION. 199 cause of the phenomena in question is identical with the cause of some familiar event ; he sees an analogy between the phenomena, and he imagines an identity of cause; the result is a new hypothesis. After the formation of the hypothesis, its value requires to be tested by ascertaining whether it is able to explain all the phenomena. § 113, There are hypothetical explanations of phenomena which can 7iever be the objects of direct observation, and in this case imagination may be occupied in an endeavour to represent them before the mind. The cause of the sensation of light or colour, for example, is and always must be hypo- thetical. The generally accepted hypothesis is that the whole of space is pervaded by a very refined ether, and in that ether vibrations of immense minuteness and rapidity are being perpetually pro- pagated in straight lines from luminous bodies. These vibrations, striking upon the retina of the eye, cause the sensation of light. Now in this hypothesis the vibration is the essential element; the ether is an hypothetical addition, invented for the purpose of making the imagination of the vibration possible. A vibration with nothing to vibrate is inconceivable ; hence it was necessary to invent an hypothetical ether in which the vibration could take place. But in imagination, ether is represented as simply a refined kind of atmosphere ; and the vibrations are represented as analogous to what we are able to observe when we look at a distant object through a column of heated air. CHAP. IV. SECT. IV. Imagina- tion of hy- pothetical forces. 200 THE ELEMENTS OF THE CHAP. IV. SECT. IV. Imagina- tion in art. Mechani- cal. Thus imagiDation represents the unknown cause of our visual sensations by analogy from phenomena which we know. We clothe the unknown with forms taken from the known. But it mus.t be remembered that this does not remove the hypothe- tical character of the explanation. That which, from its nature, can never be presented to consciousness, can never be truthfully represented in imagination. But yet it is necessary, when we think of hypothe- tical causes which from their nature are unknown, that we should imagine them as invested with a phenomenal clothing in some respects analogous to what we have known. Such is the limitation of the human mind. § 114 We now proceed to examine the opera- tions of the imagination as found in the production of works of art. In the ordinary mechanical arts, the chief exercise of the imagination is seen in the skilful adaptation of means to ends. Some work requires to be done ; the mechanical genius is able to see what particular means, or what combination of means, will suffice to do the work. The means at hand are, generally speaking, of two kinds; artificial instruments, and natural forces. A great deal of genius has been at different timefe shown in devising plans for connect- ing the latter with the former, for connecting the natural forces of the world with the artificial instru- ments of man's construction. The windmill, the water- wheel, the steam-engine, the electrical machine, are all I illustrations of this connection. And the imagina- PSYCHOLOGY OF COGNITION. 201 tion of meclianical inventors has been chiefly exerted in devising scliemes for getting hold of^ governing, guiding, or modifying the various forces of Nature. § 115. In the fine arts we have a higher, although perhaps not a more useful, exercise of the imagination. Poetry, painting, sculpture, music, and architecture are the usually recognised fine arts. In the whole of these the imagination is exercised in calling up and combining images in the mind fitted to express or to excite some emotion. The artist exerts his skill generally for the cesthetic purpose of exciting pleasant emotions. But art is also frequently employed to excite in the mind emotions of sub- limity, fear, horror, or disgust. In all cases the imagi- nation is exerted in the construction of an object or the composition of a work which will be fitted to call forth in the mind of the observer the particular emotion, or combination of emotions, designed to be produced. And generally speaking, it is by the study of Nature and the construction of the work of art after the analogy of Nature that the designed effect can be successfully brought about. The artist can only employ the materials which Nature gives him, and whether he tries merely to imitate Nature or to produce something better than Nature, his imagination must be employed in moulding, re- forming, or idealising natural things. § 116. In poetry the physical material with which the artist produces his effect is language. But the words are only the signs of the mental objects of the poet's imagination ; and it is in the calling up and CHAP. IV. SECT. IV. Poetry. 202 TEE ULBMENT8 OF TEE CHAP. IV. SECT. IV. arrangement of these mental objects that the poetical imagination consists. Hence versification, rhyme, and other mechanical contrivances are not essential to the poet's art. If the language employed is fitted to call up the same ideas in the mind of the hearer as in the mind of the poet, that is all that is required of it. The aim of the poet then is, by means of words, to conjure up before the mind of his hearer or reader, images of such a nature as will excite the special kind of emotion which he desires to excite. There are various species of poetry in which this is attempted, and perhaps it is difficult to find amongst them a common characteristic. But generally speaking it appears essential to the produc- tion of the effect that there should be a certain illu- sion produced on the mind of the hearer. He must be made for the moment to believe in the reality of what he only imagines. The true artist realises the pro- ducts of his imagination. Hence a highly poetical ima- gination is sometimes thought to be akin to madness. Lovers and madmen have such seething brains, Such shaping fantasies that apprehend More than cool reason ever comprehends. The lunatic, the lover, and the poet Are of imagination all compact. One sees more devils than vast hell can hold — That is the madman ; the lover, all as frantic, Sees Helen's beauty in a brow of Egypt. The poet's eye, in a fine frenzy rolling, Doth glance from heaven to earth, from earth to heaven, And as imagination bodies forth The forms of things unknown, the poet's pen Turns them to shapes, and gives to airy nothing A local habitation and a name. M. N. D.~Act V. Sc. 1. PSYCHOLOGY OF COGNITION. 203 §117. The most important objects of the poet's imagination are scenes in Nature, historical events, facts of human life, different types of human character, and the various objects of the unknown spiritual world. All these classes afford innumerable and infinitely varied objects suitable for tbe ex&f^ ment of the most varied emotions in the human mind. It would be impossible within our limited space to enter into a full discussion of the quesUons which suggest themselves in connection with, this subject. But there are two types of the poetical imagination to wbicb we must refer. One of these we may call tbe descriptive ; the other, the dramatic. In tbe former there is an ability to describe scenes and events, it may be with great accuracy and great beauty, as seen from the poet's own subjective stand- point ; in the latter there is an ability to construct an ideal character, quite distinct from the poet's own character, and imagine the feelings, words, and actions suitable to that character. Byron is an illustration of the first ; Shakespeare of the second. Byron's Childe Harold is admirable, because it is descriptive, and he was able to describe with elegance, and indulge in the most appropriate reflections regarding the object of his description. Byron's dramas are failures, because every character is simply himself disguised. Shakespeare was able com- pletely, in his dramatic efforts, to divest himself of his own character, as it were, and assume that of the person whom his imagination created. Thus he was able to construct a wonderful variety of characters ; CHAP. IV. SECT. IV. Suhjects of poetry. Types of poetical imagina- tion. 204 THE ELEMENTS OF THE CHAP. IV. SECT. IV. Fainting and sculp- ture. and in every case he lias ascribed to them the feelings^ words, and actions which everybody will acknowledge as natural to these characters. In this wonderful power of forgetting himself and being able to imagine how all kinds and descriptions of people felt and would naturally act in particular circumstances lies the greatness of Shakespeare. § 118. Painting and sculpture differ from poetry in being more restricted as to the objects presented to the imagination and in employing a different material as the sign of those objects. The poet can roam unrestrained in every field which his imagina- tion can reach ; the painter and the sculptor can only represent what were originally objects of sight. In a very primitive period of the history of civilisation, in Egypt, in Babylon, and in India, the sculptor's art was usually employed in the representation of the national ideas of the deity. The huge size and the grotesque construction of the figures which have been preserved to this day, reveal to us the nature of the religious imagination of the people of these old days. The different parts of human and animal bodies, fearfully exaggerated in size and proportions, and strangely combined together, are formed by the artist into huge and uncouth figures, intended to express the qualities' which the people attributed to their deities. In Greece, the painter's and the sculptor's art became more natural ; the imagination was exercised to produce beautiful figures and features which should imitate, or even emulate, Nature ; the exaggeration and the grotesqueness of the old artists PSYCHOLOGY OF COGNITION. 20! were discarded, and art was cultivated for the sake of grace and beauty. The artist did not merely seek to express with truthfulness the beauty of Nature, but by combining the most beautiful forms which could be discovered into one figure, or by idealising those combinations of features or qualities which are found in Nature, he sought to surpass the beauty of Nature in his imaginary beau-ideal. § 119. Music, like the other fine arts, was origin- ally enlisted in the service of religion. Like poetry it appeals to the sense of hearing instead of the eye ; but its material consists of musical notes instead of articulate words. The arts of the musician and the poet were originally usually combined together ; the bard chanted his own or other people's productions. But in time a partial separation took place, and the art was cultivated for the sake of the pleasing- emotions excited by the melody and the harmony of musical sounds. The power of music over the emotional part of man's nature is illustrated in the mythical legends of ancient times regarding Orpheus and his lyre; we have a fine description of it in Dry den's famous Ode on Alexander's Feast ; and in the musical recitations by the Indian pandits of the Kamayana and the Mahabharata in the present day we have a survival of what was no doubt common in Homeric and Yedic times. The effort of the imagi- nation in music is exerted not merely to produce a succession of pleasing sounds, but chiefly to produce a succession of sounds which will harmonise with and express certain emotions. It is this relation of the CHAP. IV. SECT. IV. 206 THE ELEMENTS OF THE CHAP. IV. SECT. IV. musical sounds to our emotional nature wliicli gives to music all its power. There is one style of music suited to cheerful, social festivities ; another to the mournful solemnities of the funeral procession, another to the measured tread of armed men ad- vancing to the field of battle. And the art of the musician is exhibited in adapting his musical com- positions to the nature of the emotions which he wishes to excite, or with which he wishes his piece to harmonise. § 120. The art of architecture originated in an attempt to beautify and adorn the temples of religion or the houses of the wealthy. There is, therefore, in this art a combination of beauty with utility. A regard to usefulness and stability, therefore, ought to govern the architect in deciding upon the principal parts of the building ; these qualities being secured, the imagination is at liberty to add such lines and figures of beauty as may seem suitable. The art of the architect at different times has invented a con- siderable variety of style in the structure and orna- mentation of buildings, for a description of which we must refer the reader, who wishes to pursue the subject, to the numerous works of professional men who have devoted themselves to the subject. We have* now concluded our brief account of the different special modes in which the constructive imagination of the artist operates, and with one remark we dismiss the subject. The exercise of the imagination in the study or in the construction of works of art is fitted to have an ennobling and PSYCHOLOGY OF COGNITION. 207 refining effect upon the mind. It turns away tlie attention from gross, vulgar, and merely sensuous objects; and, if properly directed, cultivates those liiglier and purer emotions which, give to human life its best pleasures and to human character its greatest excellences. Section Y, kinds op eepeesentation continued j imagination in ethics and eeligion. § 121. In practical life the activity of men is directed to the attainment of some End. The Ends which men propose to themselves are very various ; pleasure, wealth, power, fame, and many others. But in every case the End of a man's life is the product of his constructive imagination; it is an ideal composed of all the elements which, from his nature, he is led to think desirable. The ethical ideal must always be constructed out of materials furnished by the actual. In our experience we enjoy many pleasures ; but we think of pleasures better and more lasting than those. In our expe- rience we perform, or we witness performed by others, actions which we approve of, which we con- sider praiseworthy; but we are able to conceive better, more generous, or more noble actions. In short, we are able in our imagination to rise, as it were, above our experience, and from what is to construct the ideal of what ought to be. "We are not here concerned with the nature of the power CHAP. IV. SECT. V. The ethical ideal. 208 TEE ELEMENTS OF THE CHAP. IV. SKCT. V. The ideal introduces conflict. Formation of ideal. hj whicli we are able to perceive the ought or duty. That is a question of ethics. But we may examine briefly the nature of the process by which the ethical ideal is constructed. § 122. In all men there are certain primary dis- tinctive impulses and springs of action — appetites, desires, passions. A person who is completely under the control of these, who is governed by them with- out reference to the feelings or the interests of others, is absolutely immoral. To be moral implies that these natural impulses are controlled and regu- lated by the voluntary power of the individual with reference to some worthy end. But they will never be controlled unless the individual sees that their uncontrolled exercise leads to evil, that is, unless he sees that there is some higher good to be attained by controlling them. The conception of this higher good is the ideal which he forms. The general effect of the formation of an ethical ideal is to make one dissatisfied with himself, to make him feel that there is an excellence of character to which he has not yet attained. There is thus a conflict produced between the actual impulses and desires on the one hand, and the ethical ideal on the other, as to which of the two shall govern the conduct. The result of this conflict' is of the most momentous importance to the happiness and welfare of the individual. § 123. With reference to the history of the for- mation of the ethical ideal it is difficult to speak with definiteness. The ideal of one person is often widely different from that of another; of one nation from FSYCHOLOGY OF COGNITION. 209 that of another. There can be no doubt but an ideal of some kind is usually formed by every one by means of reflection upon the comparative worth of different aims or objects in life. But the greatest influence is exerted by people or nations coming into contact with those who have higher moral conceptions than themselves. The power which a man of true moral worth sometimes possesses in guiding the formation of an ethical ideal in the minds of others is very great. Thus it is true in the history of morals that it is very slowly and with great difficulty, if at all, that an isolated race can rise to a higher moral elevation; while the influence of an individual or of a nation possessed of high moral qualities upon a race not so favoured is sometimes enormous. § 124. The efforts of the imagination in religion are chiefly exerted in constructing a representation of the object of religious worship. Amongst lower and uncivilised races the imagination is usually assisted by the mechanical construction of actual material idols or images. But the representation of Deity under material forms degrades our conception of a spiritual Being, and amongst all monotheistic races the representations of the Deity are mental. The idea of Deity which the human imagination constructs has varied greatly at different times and amongst different peoples. It is also a very complex idea, perhaps the most complex which can be formed. But the most important elements which have been comprehended in it appear to be the following : The CHAP. IV. SECT. V. Idea of God. 2IO TEE ULEMENTS OF TEE' CHAP. lY. SECT. V. Keiigious ideal founded, on ana- logy. Deity is imagined as the all-powerful and all- intelligent First Cause, the Moral Governor, and the Universal Father. The first of these elements of the conception identifies God as the source and the guide of the various physical forces of Nature; the second attributes to Him the moral control, that is, the rewarding and punishing of human actions; the third represents Him as having a direct and special interest in the welfare of all His creatures. § 125. Much might be said regarding the diflSculty of uniting these various elements in one complex representation, and regarding the many very im- perfect and distorted conceptions which have been formed. But we can at present only point out that the imagination can construct the idea of God only by analogy from things known. And as the qualities of our own human nature, either known to ourselves by consciousness or presented to ns in the lives of others, are the most noble objects of our experience, they are naturally the types from which our con- ception of Deity is formed. The idea of God as our moral Euler and our Father being constantly kept before the mind, there can be no doubt but the influence of this idea over conduct and life is greater than that of any other. When, by an individual, duty is performed and good is done '' as ever in his great task-master's eye,^^ there is the highest attainable guarantee that he is worthy of any trust which may be reposed in him. PSYCHOLOGY OF COGNITION. 211 CHAP. IV. SECT. VI. Section VI. PECULIAEITIES OF EEPEESENTATION. § 126. There are great differences between dif- ferent people with reference to their power of re- calling particular classes of facts. Some people have peculiar ability in remembering names; others in remembering faces; others in remembering dates. It may perhaps be assumed as a general principle that when any event or circumstance has excited a strong interest in an indi vidua? s mind, it will be easily and readily recalled afterwards. The power of memory may be very greatly cultivated by a suitable kind of training. Generally speaking it may be laid down as a rule, that the cultivation of the habit of giving close attention to any subject of study and obtaining a comprehensive and syste- matic knowledge of it is the most important con- dition of being able afterwards to recall it. There are, however, many artificial systems of mnemonics which chiefly depend upon some principle of associa- tion. Particular names or particular dates are associated in pronunciation with some arbitrary sign which serves to recall that which is signified. Some system of this kind is frequently resorted to for the purpose of enabling students to pass examinations. An artificial system of mnemonics of this kind is about as useless as the system of examination which renders it necessary. p 2 Illustra- tions of i^e- culiarities, 212 THE ELEMENTS OF THE § 127. There are many peculiarities which, we might mention in the series of representations which, in the minds of different persons, are suggested by particular objects. To different travellers going along a road or visiting places of interest, the objects presented to the eye will suggest to the mind widely different lines of reflection. The artist, on visiting the Falls of Niagara will admire the grandeur, the sublimity of the scene ; the practical uncultured American will think of the great loss of water- power which might be utilised in driving number- less mills. The followers of particular professions have peculiar lines of reflection naturally suggested to them by the objects of their knowledge. These peculiarities in the series of representations depend upon the circumstances of the individual, upon age, sex, country, education, social position, prevailing feature of character, and many other things which might be specified. That which gives to this subject its greatest im- portance is the practical effect exerted upon one's character and welfare by the spontaneous series of representations which pass through the mind. The mind is very injuriously affected by continually indulging in thoughts of sensuous pleasures, by cherishing feelings of anger or unworthy suspicions towards others, by thinking always of difficulties and hardships and thus taking a gloomy view of life. And it should be remembered that there is a cer- tain voluntary power which every one has to a certain degree, and ought to cultivate, of regulating PSYCHOLOGY OF COGNITION. 213 and controlling the representations of his mind. By a voluntary effort one is able to banish from his mind evil and injurious reflections, and dwell upon those of a better and more ennobling kind. And the exercise of this voluntary power is perhaps the most important element in self-culture. There is scarcely any power which one can possess so valu- able to him as that of self-control, and this not merely the control of external expression and action, but of the feelings and thoughts of the mind. § 128. In the constructive imagination also there are important differences to be noted between dif- ferent individuals. And here, perhaps to a greater extent than in any other department of the human mind, we may observe inherited peculiarities. Poet a nascitur, nonfit. The mechanical genius, the poet, the musician, the painter, the sculptor, and the architect, if they are not mere mechanics, but 'poets, malcers, men of creative genius, are horn. They bring with them into the world the capabiHties of becoming what they afterwards become, and what they could never become were it not for the inborn genius which they have brought with them. Ee- markable examples might be given of persons who, at a very early age, have exhibited powers in mathe- matics, in music, in poetry, in sculpture, which could not possibly have been acquired by education, and which must have been inherited. But from whom the inheritance has been derived, and how it has been transmitted, will probably always remain insoluble problems. CHAP. IV. SECT. YI. Peculiari- ties in con. structive imagina' Hon. 214 THE ELEMENTS OF THE Section VII. repeesentation of abstractions. § 129. It is frequently necessary to withdraw the mind from some of the qualities of objects for the purpose of giving undivided attention to others. This process is called abstraction. The quality or qualities to which attention is given are properly said to be prescinded from the others ; the mind is properly said to be abstracted from the qualities to which attention is not given. In ordinary usage^ however, this distinction is not attended to, and the quality singled out for special attention is said to be abstracted from the others, and is usually called an abstraction. There may be abstraction from in- dividual objects of perception, as where the colour or the figure of an object is attended to apart from its other qualities. And we have now to consider how the representative faculty operates with refer- ence to these abstractions. § 130. Considering first the qualities of a body which correspond to special sensations, we observe that their presentation can be effected only by the help of the special organ of sensation concerned in the original intuition. A colour can only be represented in connection with the eye ; a smell in connection with the nose ; and so on. Thus by the aid of the organs of sense a representation may be made of particular qualities abstracted from an object. But PSYCHOLOGY OF COGNITION, 215 tliere is a series of so-called qualities, consisting of extension, figure, position, and other modes of space whicli must not be confounded with those qualities that are the correlatives of sensations. Qualities that are the correlatives of sensations are represented by the aid of the one special sense-organ with which they are peculiarly connected. Extension may be represented in connection with any sensa- tion located anywhere in the sensorium, but notably in connection with the sensations of colour and the tactual sensation. It is to be observed further that the connection in representation between the phantasms of colour and touch on the one hand, and the idea of extension on the other, is inseparahle. It is impossible to represent a colour or a tactual sensation except as occupying some form of space. And in so far as any sensation is specially located in any part of the sensorium, the same inseparable connection with some form of space is found to exist. "We conclude then that we are able to represent the qualities of bodies which correspond to our sensa- tions apart from one another ; that we can make abstraction of the colour, or the smell, or the hard- ness, or the taste of an object, and represent any one of them apart from the others. But when we attempt to represent colour or hardness, we are com- pelled to join some form of extension with them ; there is such an inseparable connection between the two that a separation, even in thought, is impossible. § 131. Let us consider now the nature of our representation of extension or space. Extension or CHAP. IV. SECT. VII. 2l6 THE ELEMENTS OF THE CHAP. IV. SECT. VII. Of space or extension. space, coDsidered apart from theobjects whicli occupy it, is undoubtedly an abstraction. Extension, we liave seen, is the form of whicli the colour,hardness, and other qualities of bodies are the matter. And the question arises whether we can represent the form apart from the matter; we have already seen that we cannot represent the matter apart from the form, and a little reflection will convince us that the reverse is equally true. The representation of pure space or pure empty extension is an impossibility. For when we attempt to represent space, we invariably do so by thinking of the possibility of moving through it. We think that no matter how far we travel through space, there is still a possibility of going farther. And if we attempt to conceive a limited portion of space we must do so by connecting it with some sensible boun- dary, or some collections of qualities, or some pos- sibilities of motion. This impossibility of representing pure space, apart from the idea of some qualities occupying it or some objects moving through it, might be inferred from the nature of our conception of space. It is an abstract formed from particular relations of extension. But extension is the form of intuition, the form in which objective phenomena are perceived. But the form of phenomena is not itself a phenomenon^ and we therefore need not expect it to be capable of being represented as one. The doctrine which we have maintained regarding our representation of space does not affect the question as to the nature of its actual objective ex- istence. That is a question which belongs rather to PSYCHOLOGY OF COGNITION. 217 metapliysics than psychology, and which, therefore, we shall not at present discuss. § 132. In considering the possibility of represent- ing logical abstractions we must anticipate a little, and suppose the reader to be familiar with the nature of the process to be afterwards described. The great majority of the words in every language are the names of classes of objects, as man, triangle, tree, river ; and the question we have at present to con- sider, is how, if at all, can we represent to our minds the objects indicated by words such as these ? And it must be remembered that there are in Nature no things corresponding to these general names. There are plenty of individual men, tall or short, black, white, brown, or olive ; but there is no such thing as man in general as distinguished from particular in- dividuals. So there are triangles, equilateral, scalene, right-angled, and so on; but triangle in general is unknown. A little reflection will show not only that such a thing as man in general does not exist in Nature, but that it is incapable of being represented in the imagination. For if we attempt to represent what we mean by man to our mind, we shall find the representation assuming some particular form and colour, and other qualities. We cannot help it. And in the same way of all other names which indi- cate classes of objects. It is impossible to represent the connotation of a general name, as for example, triangularity, without bringing in along with it, more or less definitely, the other qualities or parts belong- ing to some particular objects of the class. CHAP. IV. SECT, VI r. Logical abstrac- tions. 2l8 THE ELEMENTS OF TEE CHAP. IV. SECT. VII. Difficulty stated and obviated. § 133. It may be asked, then, how are we able to understand the definition of a class of objects, as, for example^ a triangle is a figure bounded by three lines ? Into the definition there are not introduced any peculiarities belonging to particular triangles, and yet we are able to understand its meaning. The explanation of this is probably to be found in the relation between language and the object of thought. When a word has become attached to a particular object or class of objects, it may frequently be used without bringing into the mind the things denoted by it. And especially when words have become very familiar, they are joined together in propositions, and the propositions are assented to, although there is in the mind no attempt to realise their meaning. Thus a familiar proposition such as, A triangle is a three- sided figure, is listened to ; it has been thoroughly understood long ago, and deposited in the memory as something to be received without question; and consequently when the proposition is pronounced it excites no mental activity except a vague belief that it is quite correct. But if an attempt be made to realise a general name, or to understand a proposition in which a general name is the subject, there must be a representation of a more or less complete and definite object. § 134 The employment of words indicating classes, or general qualities, or general modes of action, as if they represented real things, has led to many erroneous conclusions. And consequently it is important that words and propositions should be PSYCHOLOGY OF COGNITION'. 219 frequently tested by attempting to realise their mean- ing, that is, by attempting to form a representation in the mind of the things which they denote. For ex- ample, if such a collocation of words be formed as, a square triangle, its illegitimacy would be at once seen by an attempt at representation. The idea of squareness and of triangularity are incongruous; they cannot be joined together in the same representation. Thus the possibility of representation is an important test of truth. It must not, however, be accepted as a test without certain limitations. There may be re- presentations formed which have no corresponding object in Nature. The formation of a centaur or any other monstrosity is quite possible and quite common. And thus the possibility of uniting in a representa- tion any given number and kind of elements or qualities is no guarantee whatever of objective truth. But^ on the other hand, the impossibility of represen- tation is, in certain circumstances and cases, the only test of truth which we possess. For example, in the proposition — Two straight lines cannot enclose a space — the absolute incompatibility between the re- presentation of two straight lines and that of an enclosed space is to us the guarantee^ and the only guarantee^ of the truth of the proposition. And we might refer to certain other simple propositions regarding primary objects of intuition in which inconceivability is unquestionably the test of truth. § 135. When, however, we take into consideration highly complex objects of thought, it becomes much more difficult to apply the test. An apparent im- CHAP. IV. SECT. vir. Realising of abstrac' tion. Test of truth. The test applied to complex objects. 220 TEE ELEMENTS OF THE CHAP. IV. SECT. VII. General idea has no separate existence. possibility of representation frequently arises simply from want of experience. For example, a prince of Siam once found it impossible to conceive water becoming solidified into ice. Ignorant rustics can- not conceive the possibility of fish, flying through the air. These and other examples show that there may be an apparent impossibility of conception arising from the want of having had the requisite experience, and that the inconceivability must not be taken as a test of truth until it has been criticised and its nature discovered. § 136. We have seen that it is impossible to represent a general idea, as that of man, triangle, except in connection with some particular individual belonging to the class. And this impossibility is taken as a sufficient guarantee that the general idea has no objective existence except as found in indi- viduals. This is true of all general ideas connoted by general names, and formed by a process of logical abstraction. For example, one of the most abstract of all ideas is that of Being ; but it is impossible to represent Being except as a predicate of particular existing things, and consequently it is absurd to speak of Being as having any objective reality^ Similar remarks might be made regarding other logical abstractions, such as The Absolute, The Infinite. The same impossibility of representation holds good with reference to them, and the same absurdity is seen in attributing to them objective reality. § 137. There is another fallacy connected with PSYCHOLOGY OF COGNITION. 221 representation to whicli we must refer. There are certain uniformities in tlie operations of Nature which, being observed, are collected together and expressed in what are called Laws of Nature. For example, it is observed that material bodies always show a tendency to move towards one another when obstacles preventing them are removed. But amongst the heavenly bodies, when there is no apparent obstacle to prevent a general collision, it is found that certain bodies, the planets, move in elliptical orbits round central bodies of a larger size. Now, by many careful observations the laws of the motion of bodies in free space with reference to one another have been discovered. But these laws are merely expressions of the relations observed to exist amongst phenomena. And when we attempt in imagination to make a representation of a Law of Nature, we cannot do so except by imagining a variety of objects related to one another in such and such ways. To attribute independent reality to a Law of Nature, therefore, is illegitimate. And yet we frequently hear Laws of Nature spoken of as being causal agents, as producing the phenomena of whose order and mutual relations they are simply an expression. Generalisation from a number of facts of falling bodies gives no force of gravitation, but only the general truth that bodies fall when unsupported, and this can never be a cause. § 138. We have hitherto considered the possibility or impossibility of representation as a test of truth with reference to the actual or possible objects of our CHAP. IV. SECT. VII. Laws of Nature as repre- sented. Represen- tation of non-phe- nomenal causes. 222 THE ELEMENTS OF THE CHAP. IV, SECT. VII. experience. But there are some things about which we speak and reason which never have been, and probably never can be objects of experience. These are the hypothetical non-phenomenal causes which we postulate to account for the existence of observed phenomena. As an example we may give Force. We are able to observe motion, that is, a relative change of place amongst bodies. We ourselves exert effort when we find some solid body in our way. That which causes the change of motion and that which resists our muscular effort is not observed except in and through the motion and the effort. The inference of an objective Force independent o£ the motion and the effort is simply an hypothesis which we make to satisfy our own minds by account- ing for the existence of the phenomenon. Moreover, this hypothetical Force can never be an object of experience ; if it were to come within our experience, it would be a phenomenon, and require itself to be accounted for. The only way in which we can in- crease our knowledge of this Force is by learning how many kinds of phenomena it is capable of pro- ducing. We might, for example, have reason to conclude that the same Force which produced motion and resistance, was also the cause of heat and light, and the phenomena of electricity. The only way in which we can represent this Force to the mind is by investing it with some phenomena of which it is regarded as the cause. And yet we know that this is not a true representation. We know that that which from the nature of the case can never be PSYCHOLOGY OF COGNITION. 223 presented to us as a phenomenon is not truly represented as one. Now liere we liave a recog- nised impossibility of representation which, is not accompanied by a rejection from our belief of the hypothetical entity. And the peculiarity of this case appears to be that the entity in question is of such a nature that it can never^ by any increase of our knowledge^ become an object of our experience. And yet we cannot in consequence of the impossi- bility of representing it reject it from our belief, since it is necessary to satisfy a want in our mental nature, a desire to account for the existence of phe- nomena which we know are neither produced by ourselves nor self-existent. CHAP. IV. SECT. VII. 224 THE ELEMENTS OF THE CHAP. V. SECT. I. Process illus- trated. CHAPTER V. ELABORATION OF KNOWLEDGE. Section I. PEEDICATION. § 139. We now advance to the study of the highest psychological process which we propose to consider, and which we have designated by the name Elaboration. We have already studied many illus- trations of this process in the preceding portions of our essay; and we are now to examine into the nature of the process itself. A few remarks will make clear to us the general character of the prob- lems which we must endeavour to solve. We see an object before us; we affirm that it has four legs and a head, and a mane and a tail; we call it a horse; we say that it is an animal, or a vertebrated animal, or a mammal. Now the question is. How or why do we make all these assertions ? What mental pro- cesses are expressed in these assertions ? Again we assert that the exterior angle of every triangle is equal to the two interior and remote angles; by what mental process have we been able to make such an assertion ? Or perhaps we affirm that the earth is a spheroidal body revolving round the sun; or PSYCHOLOGY OF COGNITION: 225 that the sun and all its accompanying planets are speeding rapidly through space. How are such propositions as these reached by our minds ? Or further we may assert that Alexander the Grreat was the conqueror of Persia, or that Gautama Buddha was the founder of a wide-spread form of religion ; why do we make such affirmations ? In short, there are a great many things which we know, although they are not immediately under the observation of our senses ; there are a great many things apparently very different from one another which we connect together in various ways in our minds ; there are a great many things which we firmly believe, although they have never been immediately known to us at all. Knowledge and belief of these various kinds are the result of a process which we have called Elaboration, and which has been variously denominated. Thought, Reasoning, Reflection, and so on. Our duty at pre- sent is to examine the nature of our mental activity in this process of enlarging and elaborating our knowledge. § 140. If we examine any part of our knowledge, whether the simplest or the most elaborate, we shall find that there is one manner in which it is uniformly expressed. When we look at an object before us we assert " That is white,'' or "That has four legs,'' or '* That is a horse.'' When we compare different classes of objects together we assert " A horse is an animal," or " The sun is a luminous body." The result of any process of elaboration is a men- tal assertion of something or other. This result, Q CHAP. V. SECT. I. Predica- tion ex- plained. 226 THE JELEME2TTS OF THE CHAP. V. SECT. I. Further explained. expressed in language, we shall call Fredication. In a certain sense, we have predication in the very simplest act of consciousness ; as when there is a con- sciousness of any simple sensation, there is a mental assertion or acknowledgment of the existence of that sensation. That a particular sensation, say of heat, or colour, or smell, exists is the expression of the conscious act in which it is known. But this implicit assertion of existence regarding the simple objects of consciousness can scarcely be called Predication as we must understand Predication in its present con- I nection. Another illustration will make clear what we mean. An object of perception is before us ; it is yellow, heavy, tasteless, and of a rounded irregular figure ; the name gold has been associated with it ; l by a little experimenting we discover that it yields and changes its form by repeated strokes of the hammer. We assert, ^' This piece of gold is malle- able.^^ In other words, we predicate a certain quality, J malleability, of the object, that is of the aggregate collection of qualities which we called gold. And our predication here means simply that the quality malleability co-exists with a certain number of other qualities to which there has been attached a certain sound, gold. Predication in this case is the assertion that one ohfect of our Imoivledge, a particular quality, hears a certain relation, that of co-existence or co- inclusion, to another object of our hnowledge, an aggregate of qualities having a special name. § 141. If we take any other case of predication we shall find something similar. We see two sticks PSYGEOLOGY OF GOGNITION. 227 CHAP. V. SECT. I. or two lines placed side by side, and we perceive them to be either equal in length or unequal. We predicate that the one is equal or unequal to the other ; or that the one object of our knowledge bears a certain relation, that of equality or ine- quality, to another. Similarly, there may be two colours placed before us ; we predicate that the one of them bears to the other a relation of similarity or dissimilarity. So, when one object of conscious- ness is observed to appear immediately before or immediately after another, we predicate that the one bears a certain relation, that of antecedence or sequence to the other. Thus in all cases it will be found that Predication consists in the affirmation that one object of our thought hears or does not hear a certain specified relation to another object of our thought. § 142. We must now consider the ground or grounds upon which predication rests. How is it that we are able to make a predication regarding the relation which two or more objects of our thought bear to one another ? Is there any other mental act of which predication is the result ? A little examination will show that there is. When we observe two colours and predicate that the one is similar or dissimilar to the other, the act of pre- dication is manifestly the result of seeing the simi- larity or dissimilarity of the two objects. Before we can predicate two lines to be equal or unequal, we must ^perceive their equality or inequality. In other words, predication is, in some cases at least, founded upon Intuition ; we intuitively perceive j Intuition Q 2 Basis of predica- tion. 228 THE ELEMENTS OF THE CHAP. V. SECT. II. Inference. certain relations to exist between certain objects of our knowledge, and as tlie result of that intuition we predicate the relations. In other cases we must admit a different ground for our predications. For example, when we affirm, ^* The exterior angle of a triangle is equal to the two interior and remote angles/^ this is not the result of immediate in- tuition. There are various comparisons to be made before we can recognise the truth of the predica- tion. So when we affirm that the earth bears a certain regularly varying relation in space to the sun, or in other words, that the earth revolves around the sun in an elliptic orbit, this predication is by no means the result of intuition, but of a mental process of a very complex kind. The more or less complex process by which we are enabled to predicate relations between objects of our thought which we do not intuitively perceive is called Inference. But, as a general rule, intuition and inference are combined in affording a ground for our predications. We intuite certain relations to exist, from which we infer certain other relations to exist, and predicate accordingly. The nature of inference will be explained hereafter ; in the mean- time we must give some attention to our intuitions. Section II. INTUITION. § 143. That act of the mind which we have called Intuition is the immediate knowledge which we have PSYGEOLOGY OF COGNITION. 229 of any object of consciousness. Thus consciousness is co-extensive with intuition, and therefore it might appear that the term intuition was useless. But it is convenient to have some word to distinguish the knowledge given in consciousness from the know- ledge which is the result of inference^ and the word we have used appears the best suited for that purpose. Moreover, consciousness is more properly applied to our knowledge of objects or jphencmiena ; whereas we have now to bring into prominence the relations hetiveen objects. For these reasons we employ the term intuition in this part of our work to indicate the knowledge we have of objects given in consciousness and the relations between them. And manifestly, the simple objects of intuition are identical with the objects of consciousness. A. sensation, an idea, an emotion, any phenomenon of the mind, is given to us in an iu tuition. In our study of perception we have examined into the nature and kinds of sensations, and now, leaving the considera- tion of the individual phenomena of consciousness, we must consider the relations between them as given in intuition. § 144. We have already seen that we have an intuition of the relation of Sequence existing between two phenomena, and that this intuition, when generalised, gives rise to our conception of time. But there is something else involved in this relation which is of considerable importance. The phe- nomena of consciousness are usually clustered together in a very complicated way, and there are CHAP. V. SECT. II. Intuition is imme- diate knowledge. Kinds of sequence. 230 TEE ELEMENTS OF TEE CHAP. V. SECT. II. frequently sequences taking place in wliat we may deem an accidental manner. For example, tlie sound of a bell rings in our ears ; then we hear a carriage going along the road; then we see the postman coming to us with a letter. Now these various events may occur in any order, and it does not appear to be of any importance in what order they come, or whether they form a sequence at alL There is only an accidental sequence existing between them. But take another example. We see a flash of lightning ; a few seconds afterwards we hear a peal of thunder; shortly after that rain falls. Now the first two of these events cannot he reversed, at least in our experience they never have been reversed. We may have observed peals of thunder succeeding flashes of lightning at a greater or less interval of time, but we have never observed the former preced- ing the latter. Thus there are sequences which, as far as our experience goes, are irreversible. There is another characteristic of certain sequences to which we must refer. Sometimes we may see a flash of lightning, but fail to hear the expected thunder : sometimes we hear the thunder without having seen the lightning. The antecedent of an irreversible sequence sometimes takes place without the con- sequent, or the consequent without the antecedent. But in other cases the sequence is invariable. A nugget of gold is suspended by a string ; we observe the string cut with a knife ; the nugget falls to the ground. Here is a sequence which our experience tells us is not only irreversible but also invariable^ PSYCHOLOGY OF COGNITION. 231 The breaking or looseniDg of tlie thread never takes place without the object falling to the ground ; the heavy object never falls to the ground as long as the thread remains fastened to it and entire. The full significance of this we shall see afterwards ; in the meantime we note the different kinds of sequences. § 145. Another relation of which we have an intuition is that of co-existence. We have already- considered the part which this relation plays in originating our conception of space, and we need not recapitulate. We may here observe that our per- ception of external objects usually comprehends a complexity of relations of both sequence and co- existence. And further we remark that a relation of co-existence is a necessary condition of our being able to intuite the relations to which we shall next turn our attention. § 146. The relation of Likeness and JJnliheness is a most important object of our intuition. We are able to compare two phenomena of consciousness or two more complex objects of our knowledge, and to know by an act of intuition whether they are like or unlike to one another. We use the words like and unlike in a comprehensive sense, including under them various kinds of likeness or unlikeness, of which the most important are the following : — (1.) The likeness or unlikeness which exists be- tween two bodies considered as occupying space we call Equality or Inequality. Two lines being seen side by side we intuite as equal or unequal ; and so of two superficies or two solids. There is another CHAP. V. SECT. n. Co-exist- ence. Likeness and Un- likeness. Equality. 232 THE ELEMENTS OF THE CHAP. V. SECT. II. Likeness in kind. hi degree. Derived cmd com- plex rela* tions. kind of likeness between superficial figures and solids called by mathematicians Similarity , and constituted by certain proportions existing between tlie different parts of the figures. This, however, is not an object of intuition, and with it we are not therefore at present concerned. But there is an inferior and vague kind of likeness which we intuite when we compare objects which have a more or less re- sembling figure or outline. As, for example, the general figure of one horse is somewhat like that of another, although there are many differences be- tween them. (2.) There is a likeness or unlikeness perceived in the Nature or Kind of the objects of intuition or knowledge. One red colour we intuite to be like another, and to be unlike a blue colour. Any sensation of colour we intuite to be unlike any sensation of smell. And so of all objects of con- sciousness. The same intuition takes place with reference to complex objects of knowledge, and to parts of which they are composed. (3.) We are able also to compare in intuition the Degree or Intensity of objects of consciousness. There are many things agreeing in kind but differ- ing in degree, and the perception of this agreement or difference in degree is, in the case of simple phenomena of consciousness, a matter of intuition. § 147. The relations to which we have referred in the preceding paragraphs appear to be those which are primary; but there are many other relations of which we usually speak which may be PSYCHOLOGY OF COGNITION. 233 reduced to one or ofher, or some combination of the preceding. We speak, for example, of the relation between the sign and the thing signified ; but this upon examination will be found resolvable into that of sequence. So also of the relation of cause and effect, using cause in its phenomenal sense. Again, when we say that an object comprehends certain qualities, as that a horse is vertebrated, we mean that there exist certain relations of co-existence or immediate sequence between the quality vertebrated and the other qualities which make up our concep- tion or intuition of a horse. So of the relation of parts to a whole, and various other relations which might be specified. § 148. We must be careful to distinguish the use of intuition as described in this section from another employment of the word which seems not so appropriate. Some writers mean by in- tuition the knowledge which we have of certain first principles which are universally present in the human mind, and the belief of which springs up by a necessity of our nature, but in a way which we cannot explain. The universality, necessity, and inexplicability of a belief are the marks by which it is known to be an intuition. This use of the word appears to be objectionable. An intuition ought naturally to mean the act of seeing something directly, and therefore know- ing it with certainty. Now there are many beliefs which are necessary and universal, such as the belief in some objective cause of the things which CHAP. V. SECT. II. 234 TEE ELEMENTS OF TEE CHAP. V. SECT. III. Predica- tion not arbitrary. Law of identity. we know as constituting tlie natural world, wliicli are tlie result of inference and not of intuition. And the so-called intuitions of tlie mind spoken of by some writers will probably be found in some cases capable of analysis into simpler elements. Section III. DEPENDENCE OF PEEDICATION UPON INTUITION. § 149. The connection of Predication with Intui- tion, is not an arbitrary or fortuitous connection. A certain intuition having taken place, the predication which follows from it may not be this or that or something else according to choice ; but there are certain laws which govern us in founding mental assertions upon intuition. These laws may be very briefly stated and illustrated. We have before us various objects of intuition ; they may be sensations, they may be objects of perception, they may be rela- tions, or anything else immediately before conscious- ness. Let us indicate them by the first letters of the alphabet. We intuite the object A ; it is necessary for us to predicate " this is A; " it is impossible for us to predicate " this is not A." This law of thought is usually known as the Axiom of Identity , and thus expressed : A is A, i.e., everything is what it is. Again, we intuite a certain relation existing between A and B. Upon this intuition is founded the predi- PSYCHOLOGY OF COGNITION. 235 cation "A is B;^^ and it is impossible for us to predicate ^^ A is not B." This is usually called the Axiom of Contradiction ; and its formula is^ Predica- tions opposed contradictorily to each other cannot both be true. The one or the other must be false, and from the truth of the one follows the falsehood o; other. These two axioms express the natur dependence of predication upon intuition, simply an analytic statement of the princi predication must in all cases be conformable £" intuition on which it is founded. Whatever is giverb in intuition must be asserted in predication ; and it is a mental impossibility to assert the opposite of what is given in intuition. Or if the assertion be made in words^ the mind refuses to acknowledge its truth. § 150. These two laws of the dependence of predication upon intuition furnish us with the ultimate test of truth. That predication which is exactly conformable to the intuition of which it is an expression must be true. Intuition is to us the only perfectly reliable source of truth. If we are immediately conscious of any object, it is impossible for us to doubt the existence of that object, because there is no more authoritative or reliable source of information than consciousness. When, therefore, we intuite any of these objects which, we have seen, are given in intuition, we are compelled to recognise them as existing as they are known ; there is no room or no reason whatever for doubting. And •when, from this intuition^ the predication has been CHAP. T. SECT. III. Contradic- tion. Test of truth. 236 TEE ELEMENTS OF THE CHAP. V. SECT. III. Errors in applying test. made according to tlie above-mentioned laws, we accept it as true ; we cannot help it. § 151. Notwithstanding the absolute certainty of this test of truth, if properly applied, a great deal of error has crept into human belief. Arising from the application of these laws, the error may have two sources; it may arise from supposing some mental act to be an intuition which is not really so ; or it may arise from forming some predication which does not exactly express what is given in the intuition. As an example of the former we may take the metaphysical doctrine of substance or sub- stratum. It has been thought by many that the substance in which phenomenal qualities are supposed to inhere is made known to us in an act of in- tuition. But nothing can be farther from the truth ; in itself it is admittedly absolutely unhnown ; and, in fact, it is only one of several hypotheses which have been invented for the purpose of explaining the existence and objective unity of phenomena. To connect substance with intuition is therefore to give to intuition an entirely different meaning from what we consider to be the correct one. Generally speaking, both of the sources of error to which we have referred 'are most prolific in connection with acts of knowledge of a complex kind. Where the object of knowledge is very complex, or where the mental act is the result of some acquired power, it is not easy to discover what are the simple original intuitions, and consequently there is abundant room P8YCE0L0GY OF COGNITION. 2?^7 for error. But when we have before us an object wliicb we know is directly given to us in an intui- tion, and when the predication is made in accordance with the laws of truth, there is, to our minds, no possibility of doubt. Section IV. IMPLIED PEEDICATIONS. § 152. There is such a connection and complication between truths that, generally speaking, when we know and express one truth there are many other truths implicitly known and ready to be expressed. In the predications which we make regarding the objects of our knowledge we give prominence to some particular feature which it suits our purpose to express, but there may be many other relations connected with the same objects which we know, which we imply in our predications, but which we do not care to state explicitly. Almost every explicit predication is connected with other implicit predications; in being distinctly conscious of the former we know the latter also, although they may not be so distinctly before consciousness. The explicit predication stands out clearly from amidst the surrounding implicit ones, but they are in the immediate neighbourhood and simply require the attention to be directed to them in order to make CHAP. V. SECT. IV. Explicit and im- plied truth 238 THE ELEMENTS OF THE CHAP. V. SECT. IV. Predica- tions im,' ^lied and excluded. them as distinct as that whidi we have chosen to express. And it is frequently as important to know what is impHed in our predications as to have a clear apprehension of what we distinctly state. § 153. A few illustrations will bring the subject more clearly before us. When we make the general predication — All men are mortal — we have in our minds the class of men as a whole wherever they are to be found, and we predicate regarding them that they are, without exception^ liable to death. But in the very act of making this assertion there is involved the know- ledge or belief that some particular men will die. In asserting a universal predication we imply its truth with reference to any particular number. The same kind of implication is involved of course in negative predications. The Law of Contradiction is the expression of another fact regarding the relations of pre- dications. An explicit predication not only implies other predications, but may also exclude other predications. The proposition above referred to excludes the corresponding negative — All men, or some men, are not mortal. And in the same way the predicatio'n of a universal or particular negative excludes the corresponding affirmatives. To know what a particular predication implies and what it excludes is the most important condition of con- sistency in our knowledge. An important class of implicit predications is in- PSYCHOLOGY OF COGNITION. 239 volved in tlie predication of tlie internal relations of an object or class of objects and its constituent qualities. Whenever we predicate a quality of any object we thereby implicitly classify that object with others possessing the same quality. When we say, for example, that birds are oviparous, we do not satj anything about other oviparous things and we do not even mean anything about them, but if we examine the thoughts which cluster about the explicit predication we shall find amongst them that birds may be classified with other ovi- parous beings, if such exist. Were we to examine all other cases of internal predication we should find that each of them implies an external predica- tion ; whenever we predicate a quality of any object or class of objects we implicitly predicate that that object or class of objects may be included in a larger class, all of whose members are marked by the possession of that quality. This implied predication has also its corresponding excluded predication. If we can assert that objects, in consequence of possessing a certain quality, may be classified with all other objects possessing the same quality, we are precluded from making this predication with reference to objects which do not possess the quality. And, generally speaking, where two pre- dications are inconsistent with one another, if the one is either explicitly stated or implied, the other is thereby excluded. § 154. For the sake of illustration we offer the CHAP. T. SECT. IV. Illustrated !40 THE ELEMENTS OF TEE CHAP. V. SECT. IV. following examples of explicit, implied, and excluded predications : — EXPLICIT Predications. All fishes oxi- dise their blood from water. All planets move in elliptic orbits. Whales be- long to the class mammals. Alfred Ten- nyson is a poet. The angles of a plane triangle are either equal to two right an- gles or unequal. John Smith is a drunkard. The line A is double of B. The sun illu- minates the earth. IMPLIED Predications. Some fishes, or these fishes, oxidise, &c. Fishes belong to the class of ani- mals oxidising, &c. Any particular planet moves in an elliptic orbit. The class of bodies moving in elliptic orbits comprehends planets. Some mammals are whales. Some of the qualities possessed by all mammals are possessed by whales. Alfred Tennyson pos- sesses the genius and other qualities which constitute a poet. If they are equal to two right angles they cannot be unequal, and vice versa. John Smith cannot con- trol his appetite for strong drink. The line B is half of A. The sun is luminous. The sun and earth are so related in space that light from the former can fall upon the latter. EXCLUDED Predications. No fishes oxidise, &e. Animals which do not oxidise, &c. are fishes. All or some planets move in an orbit not elliptic. Bodies moving in a parabolic or other non-elliptic orbit are planets. No mammals are whales. Mammals possess no qualities in com- mon with whales. Alfred Tennyson is wanting in poetical genius. They may be both equal and unequal. John Smith can choose either to drink or not to drink strong liquorwhen he pleases. The lines A and B are equal. The lineB is greater than half of A. The sun is neither a self-luminous nor a light-reflecting body. The earth is so situa- ted that rays of light from the sun cannot fall upon it. PSYCHOLOGY OF COGNITION. 241 Having illustrated the relations between explicit and implied and excluded predications, we may sum up our results in the following canons : — (1.) Whatever relation is predicated of a class of objects may be predicated of any individuals be- longing to the class ; the denial of this relation with reference to any or all of these individuals is excluded. (2.) The predication of an internal relation of any class of objects implies an external relation, viz., that these objects belong to a larger class of things possessing the quality predicated. The denial of this and the assertion that objects not possessing the quality belong to the class are excluded. (3.) The predication that an individual belongs to a class implies the possession of the qualities con- stituting the class. The contrary is excluded. (4.) The predication of any external relation be- tween two or more objects implies the existence of all the conditions which render that relation pos- sible. The denial of these conditions is excluded. (5.) Generally, the predication of any relation excludes the predication of all other relations which are inconsistent with it, and implies the predication of all relations which are its necessary conditions or consequences. § 155. Notwithstanding the fact that these principles regulating the implication and exclusion of predications are clear and certain, there are actually found many inconsistencies and inaccuracies amongst the thoughts of men. Predications are R CHAP. V. SECT. IV. Canons of 'predica- tion. Errors in predica- tion. 242 THE ELEMENTS OF THE CHAP. V. SECT. IV. frequently thouglit to be implied whicli are not really implied^ and thouglit to be excluded which are not really inconsistent with admitted truth. And it is the great duty of the instructors of man- kind to spread abroad accurate and consistent knowledge, that is, knowledge in which established principles and facts are accompanied by everything implied in them and from which all inconsistent opinions are excluded. We may refer, by way of illustration, to some mistakes which are frequently made or have been made in determining the im- plication or exclusion of predications. In judging of the national characteristics of foreign peoples, striking features are often erroneously supposed to be universal, and false judgments are consequently pronounced in par- ticular cases. Englishmen are of the opinion that the G-ermans are a musical people, and it might be supposed that every particular German is a musician either actually or potentially. But such would be doubtless a mistake. Europeans are of opinion that Bengalis are an untruthful people, and many of them in Bengal act upon the belief that the word of no Bengali is to be trusted. This is unquestionably an error. Bengalis, oil the other hand, are of opinion that Englishmen are harsh and overbearing, and frequently apply this judgment indiscriminately. This is equally erroneous. Defenders of the Jewish and Christian Scriptures maintain their accuracy and truth, and many of PSYCHOLOGY OF COGNITION. 243 them think that it is implied that every statement must be accepted as literally true, and they will not admit any hostile criticism which results in disclosing any inaccuracies or inconsistencies. Believing that the Scriptures are true they think that if anything in them is shown to be inaccurate there is nothing worth preserving. They do not see that the presence of most important religious truth in the Scriptures is quite consistent with the presence of many scientific and historical inac- curacies and many inconsistencies amongst details. Consequently when they learn that inaccuracies or inconsistencies have been pointed out they fear that the citadel of their faith has been taken and that they can have no confidence in any religious truth whatever. The same foolish position is frequently assumed by the enemies of Christianity. Some of them appear to think that_, if they have shown statements in the Scriptures to be scientifically or historically inaccurate or mutually inconsistent, they have demonstrated the falsity of Christianity, whereas in reality they have not approached the foundations of the Christian faith in their attacks. Similarly, in former times, it was usual for the followers of rival creeds to attack with virulence subordinate details in the religious systems or Scriptures of their antagonists, thinking by so doing they were aiding their overthrow. And generally speaking, sectarians are those who are unable to see that there may be possessed great and important religious truth quite consistently R 2 CHAP. V. SECT. IV. 244 THE ELEMENTS OF TEE CHAP. V. SECT. IV. Apparent inconsis- tency of predica. tions. along with many minor points of form or doctrine which they cannot agree with. § 156. In philosophical doctrines there may often be an appearance of inconsistence between two predications when in reality they are quite consistent. For example, Mr. J. S. Mill has endeavoured to show that Sir W. Hamilton's Doctrine of the Kelativity of Knowledge is incon- sistent with his Doctrine of Immediate Percep- tion. In the former doctrine Hamilton maintains that we do not know things-in-themselves ; in the latter doctrine, that we have an immediate knowledge of real things. Mr. Mill assumes that the things spoken of in the former doctrine are the same as the things said to be known in the latter, and upon that assumption rightly concludes that the one statement is inconsistent with the other. Now it appears to us that a careful examina- tion of Hamilton's writings will show that Mr. Mill is incorrect in his criticisms, and that Hamilton in the two doctrines is speaking of two quite different things : in the Doctrine of the Relativity of Know- ledge he teaches that the cause or substratum which underlies the objects of our senses is unknown ; in the Doctrine of Immediate Perception he teaches that the objects of our senses are directly known ; and between these statements there is certainly no inconsistency. Again, there are many in the world who believe that God's will is sovereign, or that all events in their lives are controlled by Fate ; and frequently PSYCHOLOGY OF COGNITION. 245 they think that this implies that their own efforts in adverse circumstances are unavailing. They cannot reconcile the sovereignty of God with the importance of exercising all their own power and wisdom at all times as if they were sovereigns of their own lives. In consequence of permitting the idea of an over- ruling sovereignty to fill their minds to the exclusion of the idea of their own personal responsibility, when temptation or adverse circumstances come upon them, they yield without an effort and prove how helpless and worthless man is if he have not a lively sense of his own dignity and responsibility. Sophistical reasoners in their attempts to mislead the people usually endeavour to show that opposing statements are quite consistent, or that really con- sistent statements are incongruous. And generally speaking it is of the greatest importance for seekers after truth to watch carefully appearances of incon- gruity; falsehood frequently comes veiled under the one, and truth is frequently concealed by the other. Doctrines apparently conflicting may frequently be comprehended harmoniously under a higher truth; and doctrines joined together in some human system may be as inconsistent as light and darkness. Section Y. THE class; the concept; the name. § 157. We have hitherto been concerned with individual objects of knowledge and the relations CHAP. V. SECT. V, Objects, how known. 246 THE ELEMENTS OF THE CHAP. V. SECT. V. existing between them. We must now consider a mental process in wHcli tlie individual objects tbat we know are variously joined together into classes. And it must be borne in mind that, in this connec- tion, when we speak of objects, we mean not merely objects of simple intuition, but also objects or results of more complex mental processes, such as perception. Our knowledge of any object is made up of all the predications which we can form regarding it. Having perceived any object, we express our knowledge of it by predicating that it possesses such and such various qualities. And in the case of each predication we mean that the quality referred to in it exists in a certain relation to the aggregate of the other qualities contained in the other predications. Now, in considering any object of thought, we are able to restrict our atten- tion to a limited number of the qualities of which it is an aggregate, to separate them in imagination from the rest and consider them by themselves. The qualities to which attention is thus ex- clusively given are said to be abstracted from the others. § 158. The power of restricted attention being admitted, we further postulate an ability to compare different objects of knowledge with reference to the possession of abstracted qualities. Having a number of objects before us we can, by observation, ascertain whether they all possess or do not possess a certain quality or qualities to which we have given atten- tion. If we find that they all actually possess this PSYCHOLOGY OF COGNITION'. 247 quality or these qualities we naturally attribute to tliem a kind of unity ; we tHnk of tliem as forming a class ; we apply to tliem some common name- Thus the reason why we collect individual objects into classes and designate them by a common name is that we are able to predicate concerning them all some specified quality or qualities. Now, in this process there are three things to which we must give attention : first, the abstracted qualities ; second, the class which has been constituted by virtue of the possession of these qualities; and third, the use and meaning of the name. § 159. In order that the process of generalisation may be possible, it is absolutely necessary that our attention should be restricted to some of the quali- ties of bodies ; because amongst the bodies with which we are acquainted variety is uniformly to be found, and in order to reduce them to unity we must disregard the qualities in which they differ. Having, therefore, by observation abstracted certain specified qualities in the possession of which a number of objects agree, these qualities taken together form a kind of mental object ; in the act of representation, although we may not be able to banish altogether all the other qualities of the bodies, yet we give to them peculiar prominence ; we attribute to them a kind of separate existence, which, although no doubt ob- jectively fictitious, is mentally real. These ab- stracted qualities thus mentally unified we call a Concept. Now the question arises, Upon what principle is it that we choose certain qualities CHAP. V. ConcejpU. 248 THE ELEMENTS OF THE CHAP. V. SECT. V. Formation of a con- cept. Common qualities. Peculiar qualities. of objects for abstraction and unite tbem into a Concept ? § 160. In answer to tlie question proposed, it is in tbe first place manifest that no qualities need be cliosen except such as are possessed by all the objects concerned. If we can at all unite objects into a class it must be by means of something which they possess in common ; some quality or qualities in which they all agree. Thus we have one principle at least to guide us in the formation of a concept. Nothing can form a part of the concept which is not possessed hy all the objects. This principle excludes all those qualities with reference to which the individual objects differ from one another. Here again another question presents itself — Are all the qualities in which objects agree to be included in the concept ? In order to answer this question we must consider the end for which generalisation is undertaken. § 161. The reason why we collect objects into classes is that we may know them better. But in this connection, more complete knowledge does not mean a more perfect knowledge of the qualities possessed by each individual. Our knowledge of classes is made complete by our being able to compare them with other classes, and know in what respects they agree and in what respects they differ from them. Hence, when we wish to have an accurate knowledge of a class, it is not sufficient merely to collect into a mental unity all the qualities in which the objects of the class agree with one another ; we must also consider in what qualities PSYCHOLOGY OF COGNITION. 249 this class differs from other co-ordinate classes. The points of difference are manifestly of great import- ance^ because it is only by these that there can be a distinction made between the class in hand and other classes. Thus we have two collections of qualities to be considered ; those in which all the objects of one class agree, and those in which this class differs from other classes. For the sake of clearness let us suppose. a \ h i to be qualities pos- c f sessed in common d ^hj all the objects e \ of the class f 1 A, and to be qualities pos- sessed by all the objects of the class Now if we formed our concept of the class A without comparing it with other classes, we should include in it all the agreeing qualities a, h, c, &c. But when we compare the two classes A and B, we find that they agree in the possession of the qualities hj d, fj and they differ in that A possesses a, c, e, which are absent from B ; whereas B possesses li, Ij which are absent from A. Consequently /or the m puiyose of distinguishing A from B we must reject from the concept of A those qualities in which A agrees with B, viz., 5, d,f] and we must include in the concept of A the qualities a, c, e, in which A differs from B. Thus for the purpose of distinguishing one class from other classes, special attention must be given in the formation of the concept to those qualities which constitute the differentia between it and other co-ordinate classes. § 162. Are, then, all the points of agreement CHAP. V. SECT. V. Formation of higher classes. 250 THE ELE3IENTS OF THE CHAP, V. SECT. V. How to assign an object toils class. between tlie class A and the class B to be rejected from tbe concept of A? If our object were merely to distinguish A from B we should reject them. But as we wish to systematise our knowledge, to bring all the classes of objects into relation with one another, the points of agreement between classes are mani- festly of great importance. For if we consider as objects the lowest classes which we have formed, and observe the points of agreement between them, we shall be able to form a higher class, comprehend- ing all these lower classes in the same way as they comprehend individual objects. And this process of classification may evidently go on until all the objects with which we are acquainted have been combined together by virtue of their possessing some- thing in common. Kow, in order to connect any particular class with this system of classes, it is necessary to know not merely in what respects it differs from other co-ordinate classes, but also by virtue of what qualities it is comprehended under a more general class. And these qualities, called generic, must therefore be united in the concept to the differentia before spoken of. Thus the concept of any class must comprehend the generic qualities, or those in which the class resembles other co-ordinate classes, and fhe differentige, or those qualities which distinguish it from these classes. § 163. Having explained and illustrated the general principles of classification, we now proceed to study the process of assigning any particular object of our knowledge or thought to its appropriate PSYCHOLOGY OF COGNITION. 251 ■class. To be able to do this correctly is a matter of great importance, as we do not know an object accurately until we know what class it belongs to. Before we can classify any individual it is manifestly necessary for us to know that it possesses the essential qualities of some class ; having ascertained this we immediately assign it to that class. We see, for example, an object rooted to the soil, evidently organic, and having a stem, branches, and leaves. Knowing that these qualities are possessed by many vegetables, we assign our individual to that class. A further examination reveals the fact that the object has flowers growing upon it, that the leaves are netted instead of parallel veined, that it has a woody stem composed of a number of circular layers around a central pith. Knowing something of botanical classifica- tion we call our plant an exogenous flowering plant. Pursuing our examination into minute characteris- tics of the flower and the leaves and the seeds we succeed in determining the Order, the Genus, and the Species of the plant. Thus it appears that all that is necessary in classifying an object is a knowledge of the charac- teristics of the class to which it is problematically to be referred, and a knowledge derived from examination that the object in hand presents these characteristic qualities. Having discovered the important qualities of an object we look about, unless we already know, for some class whose concept comprehends these qualities ; and having CHAP. V. SECT. V. 252 THE ELEMENTS OF THE CHAP. V. SECT. V. Difficulties in classifi- cation. found it we unite by a syntlietic act tlie individual with the other individuals of the class. § 164. As long as we are dealing with inorganic elements or organic material bodies there are no great difficulties in the way of classifying individuals. We are now able to apply chemical tests with definite and precise results to all inorganic ele- ments ; and the microscope and dissecting knife enable us to examine the minute parts of organised objects with great accuracy. And consequently it only requires a certain amount of practical training and skill to refer any object with precision to its proper class. But when we come to the more com- plex relations of human life and action much greater difficulties present themselves. These difficulties arise from the greater complexity of the phenomena with which we are dealing, from the want of such a precise system of classification as we have with reference to material objects, from the impossibility of observing such clear distinctions as are seen between organic things, and from other causes. The following are some of the objects of thought in connection with human life and action which present themselves for study and classification : — The phenomena of consciousness ; mental modes of action constituting character; bodily habits; lan- guages ; general forms of body and countenance ; national customs and superstitions ; family institu- tions ; tribal habits and laws ; forms and charac- teristics of governments; and other features con- nected with social life which will readily suggest PSYCHOLOGY OF COGNITION. 253 themselves. A few illustrations will show the difficulty of reducing these things to scientific system. § 165. When we observe an action done by some person, we often experience a feeling of pleasure or displeasure, of approbation or disappro- bation, and we judge that the action is either right or wrong. Now students of the human mind cannot agree as to what is the true nature of this moral feeling or judgment, as to whether it is primarily a feeling or primarily a cognition, as to whether it is a simple and original pheno- menon of human consciousness, or a complex and derived phenomenon found only in human minds which have attained a certain degree of advancement. Again, when we try to estimate the charac- ter of the men whom we meet there is room for great doubt and uncertainty. We some- times observe men giving large sums in charity to the poor, or otherwise trying to ameliorate their condition; and we should probably think that these were henevolent men. But it is possible, and many times true, that men perform apparently benevolent actions from some selfish motive, and the discovery of this fact makes it impossible for us to classify them as benevolent. The motive by which an action is inspired constitutes the most essential element of the action, and the difficulty of ascertaining its character renders it difficult to characterise the action. CHAP. V. SECT. V. Illustrated, 254 TEE ELEMENTS OF TEE CHAP. V. SECT. V. Comnnon errors in claasifica- tion. Suppose, again, that we wish to determine whether a certain writer is a poet or a philosopher^ it is not in all cases easy to do so. There are versifiers who are not poets ; and there are many who write about philosophy but are not philosophers. And critics are not by any means agreed as to what it is that constitutes a man a poet or a philosopher. Thus we have here a twofold difiiculty ; the essential qualities of the classes are not determined with precision ; and even if they were determined it is no easy matter to say in any particular case whether a person possesses them. It requires a certain amount of poetical or philosophical genius to esti- mate the quality of poetic or philosophical writings. Students of language also find great difficulty in classifying the different languages of mankind. Leading distinctions have no doubt been observed and form the basis of a provisional classification, but the science is yet in its infancy, and much has to be done in the way of determining the characteristics of different languages and arranging them into a system. Similar remarks might be made with reference to most of the problems of classification which arise in connection with the intellectual, moral, and social life of man. And we may now point out a few leading errors which we are apt to make in our study of the phenomena in question. (1 .) Errors are often made in failing to distinguish the essential or predominating character of that which we are examining. A man may conceal PSYCEOLOGY OF COGNITION. 255 under a harsh and forbidding exterior a really kind and generous heart ; the manner of a man is most frequently that by which he is at first judged ; and thus people frequently form an erroneous judgment by not looking through the manner at the more essential qualities of mind and conscience. (2.) Errors in classification arise from supposing things to differ which in reality are the same or similar. For example, Sir W. Hamilton supposed that Dr. Reid's theory of perception was quite different from and inconsistent with the representa- tive theory held by Dr. Thos. Brown and others of Eeid^s predecessors. In truth, although there were minor differences, the essential doctrines of Reid^s theory are not what Hamilton supposed, and are not so different from the doctrines of Brown as to entitle them to be put into a different class. Real resemblances are often concealed under a difference of phraseology, and it is an important function of thought to penetrate beneath the verbal expression of doctrines to the ideas taught. (3.) Errors in classification arise from supposing things to resemble one another which are in reality different. Things indicated by the same word, for example, especially if the things indicated are mental in their character, are at first sight supposed to be the same, but in reality they are frequently found to be very different. Names, in the course of time, often change their meaning, and it is frequently very difficult to observe and discriminate the different meanings which, at successive times CHAP. V. SECT. V. 256 TEE ELEMENTS OF TEE CHAP. V. SECT, V. Essential and acci- dental qualities. and as used by different persons, tliey carry witli them. Tlie philosophical name idea presents us with a good example of a word which means very different things as used by different writers or even by the same writer. Not only may single words mean different things, but also similar forms of expression may be very ambignous in meaning ; of this, good specimens are given in many of the ancient oracles which were usually susceptible of quite different interpretations. And the writings of sophistical reasoners are usually filled with forms of expression which convey one meaning to the mind of the reader, but are used to express quite a different idea of the writer^s mind. § 166. There is a question of importance con- nected with the nature of classes now to be considered. Have classes only a mental existence ? Have they an existence only in the concept by which the mind binds them together ? If they have not, then one concept, provided it be constituted as we have shown it should be, will be just as good as another. If the differentias of a class are all duly observed, and included along with the accurately known generic qualities in the con- cept, these differentiae and generic qualities being discovered only by the test of difference and agree- ment, the concept thus formed must be unex- ceptionable. But it is actually found that men of science, in constructing a classification, select from amongst all the points of difference and agreement certain qualities which they think to be of greater PSYCHOLOGY OF COGNITION. 257 importance than others. They frequently reject from their definition of classes some qualities which by reason of agreement and some which by reason of difference should be included. An illustration will make plain what we mean : Fishes ( a. live in water. 6. are vertebrated. c. obtain oxygen for their blood from the water. d. propel themselves by fins. e. are oviparous. /. have a long round- ed figure fitting them for easy motion in water. Whales ^ a. live in water. &. are vertebrated. c. obtain oxygen for blood by breath- ing air. d. move by organs like fins. e. are viviparous. /. have a fish-like figure. Now comparing the lists of qualities possessed by fishes and whales we see that the qualities marked a, h, d, and / are identical or very similar ; while the qualities c and e are different. And the ques- tion isj Are we to include whales in the class Fish ? The points of agreement are numerous. And if one quality were just as essential as another, we should probably come to the conclusion that a whale is a fish, as it was long believed to be. But men of science tell us that the points of difference to which we have attached the letters c and e are of vastly greater importance than such qualities as a and /; and they make these points of difference essential, and some of the points of agreement accidental, and consequently conclude that a whale is not a fish. Now upon what principle is it that the qualities c and e are considered essential and included in the CHAP. V. SECT. V. 2t^8 THE ELEMENTS OF TEE CHAP. V. SECT, V. What con- stitutes essential qualities ? concept of a whale, while the qualities a and / are not ? How do you know the essential attributes o£ any class ? § 167. A great variety of answers have been given to this question, and it -would take us beyond our limits to enter upon a description or criticism of the different theories which have been held upon the subject. The determination of what are the essential qualities of classes is no doubt to be accomplished by a comparison of many objects and an extended obser- vation of the relations existing between the qualities of objects. Those qualities of objects which from their nature or uniform presence appear to determine a great many other qualities, are naturally looked upon as being essential. The possession of vertehra by an animal, for example, must be considered an essential quality, because we observe that it is the ground upon which depend a great many qualities that distinguish a vertebrated from an invertebrated animal. The principles upon which the selection of essential qualities depends are, however, a matter of science rather than of psychology. But it is of importance to observe here that we have established the fact of the objective existence of natural classes of things. There is a reason in the nature of things them- selves for their being brought together in classes. There are essential qualities comprehended in ob- jects; and it is only when we make our concepts to comprehend the same essential qualities that we have an accurate knowledge of the objects. A concept is true only whea it comprehends the PSYCHOLOGY OF COGNITION. 259 essential qualities of the class from wliicli it is derived. § 168. We now give some attention to tlie names which we give to the various classes of objects that we know. The study of the science of language has brought to light many interesting and important facts connected with the application of names to objects. The simple names which primitive peoples give to the objects of their knowledge are usually expressive of some striking quality possessed by the objects. A river, for example, may be called the running thing ; the sun is named from its shining quality ; the stars from twinMing, or perhaps shining. A name which is at first significant of some striking quality or action possessed or performed by an indi- vidual object is afterwards applied to other objects possessing a similar quality; and thus arises the first rude classification. Now, it must be observed that the name is attached to the objects individually ; be- comes so associated with them as to form, as it were^ one of their qualities. And upon its first application the name expresses the concept which the name-giver had in his mind when he invented the name ; that is, expresses the quality which, to his mind, was most striking, and therefore most important. But as know- ledge increases the nature of the concept changes ; other qualities of the object are discovered which are found to be of greater importance than those first observed ; but no corresponding change takes place in the name. Thus the natural class and the name are constant^ while the concept is variable. And s 2 CHAP. Y, SECT, Y. Names, 26o THE ELEMENTS OF THE CHAP. V. SECT. V. Denota- tion and connota- tion. the question arises^ What is the psychological significance of the name ? § 169. It is usual to say that a name denotes objects and connotes attributes ; and it is usual to assume that the objects denoted are the objects of the class of which the attributes connoted are the essential attributes, that is, the concept. Now it is quite correct to say that the name denotes to all minds the objects of the class with which it has become asso- ciated ; but it is not correct to say that the name connotes the attributes of the scientifically-formed concept. We have seen that the concept is a very variable mental object depending upon the knowledge and mental habits of the individual in whose mind it is formed. And, moreover, the concept is never represented in the mind without bringing along with it other accidental attributes forming no part of itself. And unless we arbitrarily restrict the connotation or meaning of a name, we shall hold that it connotes all the attributes essential or accidental which it is the means of bringing before consciousness. Thus it would be very difficult for any one to pronounce or hear the word fish without thinking of the quality swimming in the water , which is an accidental one. And it is in only a small number of minds that the sound of the word " fish " would suggest the quality of water-hreathing j which is a constituent element of the concept. Thus we should say that while the denotation of a class- name is invariable, or varies only in consequence of some change in the class, its meaning is, in PSYCHOLOGY OF COGNITION. 261 different minds, exceedingly variable, depending not only upon the variation of tlie concept, but also upon tlie introduction into the mental image of a variety of accidental qualities. In consequence of this variability of the meaning of names, scientific men have, to a great extent, ignored the ordinary names of common language, and invented a scientific vocabulary whose words should connote only scien- tifically-formed concepts. Thus the principle is re- cognised that, in a scientific interest, the names of classes ought not only to denote the classes, but also to connote exclusively the attributes of the concept. But it remains equally true that in the ordinary affairs of life the names which we use have a very variable meaning, but are used to denote something which is practically invariable, a really existing •class. § 170. A great deal of confusion has been caused by the application of the epithet general to the names which have become associated with classes and to the ideas, as they are called, which we form of classes. It appears to be assumed that the result of the process of generalisation must be itself general; and the question has long been discussed, Where is the assumed generality to be found ? Realists have held that there is a general idea existing in Nature; conceptualists maintain that generality is to be found only in the mental concept ; nominalists contend that nothing but the name is general. The truth is, we might as well speak of a square circle or a green smell as of a CHAP. V. SECT. V. General names and ideas. 262 THE ELEMENTS OF TEE CHAP. V. SECT. V. Defini- tion. general idea or a general name. Every concept whicli we form is an individual collection of quali- ties ; every name which, we utter is an individual sound. The name has become associated in our minds with certain similar objects which, in conse- quence of their similarity, we think of as forming a class. The concept consists of a number of quali- ties which we have observed to exist in all the objects belonging to the class. The name is pre- dicable of all the objects of the class, and therefore, if we insist upon using the word general, we may say that the application of the name is general. The qualities of the concept are predicable of all the objects of the class, and therefore we may say that the qualities represented in the concept are generally or universally found in the class. And in fact it is the universal presence of the essential qualities in all the objects of the class which is the ground both of the general application of the name and of the formation of the concept. And, conse- quently, that which we mean by a name and that which we represent in a concept has a real existence only in the particular objects of Nature. § 171. The exposition in language of the quali- ties of a concept is called Definition ; the arrange- ment in subordinate groups of the objects denoted by a name is called Division. But it must be remembered that the definition is accurate only when the concept is true. For a definition to be correct it is necessary that the concept of which it is an expression should comprehend the essential PSYCHOLOGY OF COGNITION. 263 qualities of tlie class ; if the essential qualities are not known, if the class is recognised only by certain accidental superficial attributes, a correct definition is impossible, and we must be satisfied with such an indefinite description of the class as may be within our reach. The important point which we wish to bring out here is that a definition^ to be correct, must conform to objective existence ; that this con- formity is brought about through the medium of a true concept; and that unless the concept corre- spond to real existence, a correct definition is unattainable. Division is a process the reverse of classification. As by the perception of mutual agreements we unite objects into classes, so by the perception of mutual differences we separate classes into subordinate groups. The rules of both definition and division are given in logical works, and these rules assume that we are always able to test the accuracy of a definition or a division by means of intuition. By intuition, that is, by direct observation, the concept is formed and the class is determined, and when we attempt to elaborate concepts and classes into systems, it is only by reverting to intuition that we are able from time to time to test the correctness of our systems. The limitation of the sphere of logic, therefore, simply to the exposition of the nature and relations of concepts, without any reference to the truth of those concepts, is, judged from the pyschologist's point of view, a blunder. We are not satisfied with consistency amongst concepts which may be crude or erroneous CHAP. V. SECT. V. Division. 264 THE ELEMENTS OF THE or baseless ; we must have our systems of science continually tested by a comparison with, tlie truth of Nature^ otherwise they are simply castles in the air. Consequently it is unwise to separate the sphere of logical thought from that connection with the real world which is afforded to it in the continually possible exercise of intuition. ' Section YI. peedication again. § 172. We have seen that Predication is the mental assertion, expressed in language, that one object of thought stands or does not stand in a certain relation to another object of thought. We have seen the dependence of predication upon intuition, and the part which it plays in the forma- tion of the concept. And before proceeding to consider the more complex processes of thought, it will be desirable to understand more fully the nature and kinds of predication in itself. Predication is founded upon a union in consciousness of the two objects of thought of which the one is predicated of the other. The union in consciousness may correspond to an external objective union, or it may not ; but a subjective union there must be in order to render predication possible. The terms of the predication, the things between which the relation is affirmed to exist, are called Subject and Predicate respectively. Since a union in consciousness is a necessary condition of predication, it follows that PSYCHOLOGY OF COGNITION. 265 any proposition wliose subject and predicate cannot be tbus united must be unmeaning or false. If we assert in words, " A circle is a triangle/' and attempt to think together in consciousness the subject and predicate, we shall at once see that although a pro- position has been constructed no intelligible predica- tion has been made. There are, then, what we may call i'mpom^Ze predications ; which are such that the mind is incapable of bringing together the subject and predicate into the relation which is asserted to exist between them. § 173. Again, there maybe objects of knowledge united together in consciousness, of which the one cannot properly be predicated of the other. For example, we may have in consciousness together the sweet smell and the red colour of a rose ; but it would be absurd to predicate the latter of the former. The only way in which we can form a predication is to make one of these qualities a predicate of which the whole aggregrate of qualities, along with the name rose, is the subject. Thus, when we speak of objects of perception,we invariably make the complex objectified group of qualities the subject, and some one or other of the qualities the predicate. Now if we have in the same moment of consciousness a sweet smell and a red colour, it might appear just as reasonable that we should predicate the co-existence of these two qualities as the co-existence of one of them with the aggregate of qualities constituting the rose. But this is not so, and the reason appears to be that the aggregate of qualities has come to be CHAP. V. SECT. VI. Some unions im- ^possible. Accidental co-exist- ences not joined in 'predica- tion. 266 THE ELEMENTS OF THE CHAP. V. SECT, VI. Classifica- tion of relations. looked upon as having more tlian a relation of co-existence with, the single quality which is predicated of it. The aggregate of qualities is regarded as an object, a united- whole, of which the single quality is a constituent part. There is a permanent and indissoluble connection between the qualities which is not truly expressed when it is predicated of them merely that they co-exist with one another. And this permanent objective connec- tion is the reason why the whole aggregate is usually made the subject of predication. § 174. From a careful examination of the nature of predication we have seen reason to conclude that it is the assertion that some relation or other exists or does not exist between certain objects of our thought. There are four great relations in one or more of which the phenomena of our consciousness must stand towards one another : — the relations of Difference, Eesemblance, Simultaneity, and Succession. If now, we consider the objects of our knowledge we shall reach another division of relations subor- dinate to the above. All objects which are related to one another may be distinguished into quantities and qualities. The latter correspond to the sensa- tions of which we are or may be conscious; the former consist of the Form of sensations or objects, namely, the space, time, motion and so on, by which sense objects are conditioned. Again, the relations of all objects or classes which may be predicated are either internal or external; the former being P8YGE0L0GY OF COGNITION: 267 the relations of objects or classes to internal con- stituent qualities or parts, the latter to other ex- ternal objects or classes. Internal and external relations may be both quantitative and qualitative, and thus we have a fourfold division of relations into : — I., Internal Quantitative; II., Internal Quali- tative ; III., External Quantitative ; lY., External Qualitative. This classification is founded upon and not exclusive of our former division of the four primary relations, as will be seen from the following table : — I. Internal Quantitative Relations com- prehend : — Eolations of figure, size, shape, motion, number, and so on, of the con- stituent parts or elements of objects, classes or systems. These relations may be any of the four pri- mary relations or any combina- tions of them. II. Internal Qualitative Re- lations compre- hend : — Relations be- tween the qua- lities of objects of our know- ledge, or classes of objects,these qualities being made known to us by the sen- sations or ideas which they pro- duce in our minds. III. External Quantitative Relations com- prehend : — Relations of any of the four primary kinds or any combina- tions of them between the figure, size, shape, motion, duration, num- ber, and so on, of objects, classes or sys- tems which are external to one another. IV. External Qualitative Re- lations compre- hend : — Relations be- tween external objects or sys- tems with re- ference to qualities made known by sense, moral or sosthe- tical qualities, characters, habits, condi- tions and any other charac- teristics of ob- jects of know- ledge which may be appro- priately called qualitative. § 175. We shall give illustrations of these great classes of relations. I. Internal Quantitative Relations. When we construct a geometrical figure, as that CHAP. V. SECT. VI. Illustrated 268 THE ELEMENTS OF THE CHAP. V. SECT. VI. of the fifth, or the forty-seventh proposition of the First Book of Euclid, we constitute a unity, and the subsequent demonstration is a comparison of the different internal parts in respect of their magnitude, and the inferences which result from that com- parison. Similarly, many of the propositions of geometry consist of a combination of predications regarding the internal quantitative relations of different kinds of figures. The astronomer who studies the motions of the different bodies belonging to the solar system is engaged with internal quantitative relations. The solar system as a whole constitutes a unity, the elements of which are the sizes, masses, distances, orbits, velocities, and so on, of the various bodies which revolve around the sun or the primary planets, and of the central luminary. The mechanical engineer is similarly occupied when he arranges the figure, strength, motion, position, and so on, of mechanical structures, as houses, bridges, or machines. Comparative ana- tomists are able to complete the skeletons of animals, having given them certain of the bones. This ability is the result of careful study of the internal quantitative relations of the bodies of animals. 11. Internal Qualitative Relations, The qualities of single objects of sense often require to be studied and compared in the interests of science. The chemist in his analysis of the various organic and inorganic substances which PSYCHOLOGY OF COGNITION. 269 come under liis notice is engaged in the study of internal qualitative relations. The process of classification involves a careful examination and comparison of the internal qualities of bodies or things classified. The composition and criticism of the productions of the poet, musician, statuary, and painter, consist chiefly of the arrangement and examination of internal qualitative relations. The same relations are the objects of study when we examine the characteristics of a man, of a nation, of a government, of a religious system, of a systematic body of doctrine of any kind, of an oration, in short of any of the vast variety of things known to us which are characterised by internal differences of quality or powers of exciting ideas. III. External Quantitative Relations, In classification, when the extension or quantity of one class is compared with that of another, we are dealing with external quantitative relations. Many geometrical propositions are concerned with these relations. Comparisons of the weights, masses, figures, proportions, velocities, numbers, and so on, of distinct bodies not forming parts of a connected system, have for their objects external quantitative relations. IV, External Qualitative Relations. The botanist, zoologist, and chemist, in com- paring the different specimens of objects which come within their respective spheres of study are concerned about external qualitative relations. So CHAP. V. SECT. VI. 270 TUB ELEMENTS OF THE CHAP. V. SECT, VI. Predica- tion de- fined and illustrated is the ethnologist in comparing the characteristics of different races of men ; the philologist in com- paring the principles of different languages; the mythologist in bringing together the myths, legends, and folk-lore of different countries; and the com- parative economist in studying together the different social and political institutions which have sprung up in different countries at different times. This study of the qualitative relations of things and systems has sprung into importance chiefly in modern times, and is a very powerful method of scientific discovery. In the comparative study of physical characteristics, of moral and social habits, of myths, of religious beliefs, of languages, of institutions, of laws, and of historical events, consists the only available effectual method of discovering the beginning and the principles of human progress. § 176. Now all thought is concerned about some, or all or various combinations of the relations which we have just now classified; and the result of every comparison, as well as the expression of every relation, is a predication or a proposition. In the exposition of our own views, we shall use the former term ; in the criticism of current logical doctrine we shall use 'the latter. Predication, we may thus define as the assertion that one object or element of our knowledge or conception stands, or does not stand, in some relation to one or more other objects or elements of knowledge or conception. In order that we may clearly understand the nature and PSYCHOLOGY OF COGNITION. 271 forms of predication we shall study a few examples of it. And we shall begin with, the study of examples of the predication of internal relations. When we say, this rose is red, we affirm an internal relation of simultaneity or co- existence. The red- ness is a quality found co-existing with all the other qualities which make up our knowledge of the flower. The uniform and inseparable co-existence of these qualities causes us to think of them all as making one object ; and when we say this rose, we mean by it the 07ie object made up of all the qualities. The first term of the above predication calls up .an image before consciousness ; the second term is one of the elements of the image singled out for the moment for particular attention; the predication affirms that the element forms a part of the whole object^ or co-exists with the other elements of it uniformly and inseparably. The horse has four legs. This predication also affirms a certain internal relation of the object horse. The first term of the relation denotes a particular object composed of many parts and qualities. The second term of the relation ex- presses particular elements or parts of the whole object. The predication affirms a relation of co- existence of that regular and inseparable kind which constitutes the co-existing qualities into an individual. All predications which we make regarding the internal constitution of objects are of the same nature as the abovOj and have about the same CHAP. V. SECT. VI. 272 THE ELEMENTS OF TEE CHAP. V. SECT. VI. significance. The form of tlie predication is a matter of comparative indifference, as we are now- engaged in the study of thoughts j not of words. The same relation is expressed by all the following forms : — The rose is red ; the horse has four legs ; the house consists of six rooms ; England contains Middlesex; the lion is possessed of a shaggy mane ; the solar system comprehends the sun, planets, and satellites. And in all these cases the first term of the predication denotes a whole object, and the second term expresses some quality, part, or element of the object. § 177. Not only may we predicate internal re- lations of material objects and systems of objects, but also of mental and social phenomena. The following are examples of such predications : — A moral judgment consists of intellectual and senti- mental elements; the family is composed of a husband, wife, and children ; the Government of England includes the Sovereign, the House of Lords, and the House of Commons. The meaning of the predication in all these cases is the same as before. There are other predications of relations which may, perhaps, be called internal, but which should be distinguished from the above. These are predi- cations of intransitive actions. We may give as examples of these: — The dog barks; the fire burns; the sun shines ; the river runs ; the wheels turn ; and so on. In all these predications, and such as these, there is involved the idea of something pro- ceeding from the first term of the relation. The dog PSYCHOLOGY OF COGNITION. 273 harksj means a certain sound proceeds from the dos:. Fire hums, means tliat a certain sensation is experienced after contact with fire. The river runs, means that a body of water occupies different places at successive times. The wheel turns , means that the different parts of the wheel successively occupy different positions. The first term of each of these predications denotes some object ; the second term implies some sensation or action; and the predi- cation affirms a relation of succession between the co-existing qualities of the object and the sen- sation or action predicated. § 178. We now proceed to the examination of external relations of objects as affirmed or denied in predications, and, for the sake of convenience, shall consider indiscriminately quantitative and qualitative relations. And first amongst these we have relations of difference. A relation of differ- ence, we have seen, is absolutely necessary to enable us to distinguish one object from another. If two objects are exactly alihe in quality they must, at least, have different spatial positions to be distinguishable. Relations of difference are usually expressed by the comparative degree of the adjective which expresses the quality with reference to which two objects are compared. The following are exaniples : — Bed is brighter than green. Lead is heavier than wood. The sun is larger than any of its planets. The conceptions of '' Paradise Lost ^^ are more sublime than those of '' The Deserted Village.''^ A child is not so strong CHAP. V. SECT. VI. Predica- tion of exw ternal relations. 274 THE ELEMENTS OF TEE CHAP. V. SECT. VI. as a man. A greyhound can rim faster than a bulldog. The scenes of heaven are more glorioiis than can be expressed by language. The fruit of the pine-apple is not the same as that of the orangQ tree. In all these cases^ and in others which might be adduced, we see that the two terms of the predi- cation are the two objects compared ; and the pre- dication asserts that a relation of difference,, in some particular respect, exists between them. The words which we have italicised in the abovo examples express the relation jpredieated between the two terms ; and it is manifest that it is of no- consequence which term of the relation comes first in the predication. The substitution of the second term for the first would simply involve a slight change in the expression j but no change in the thought. Bed is brighter than green, is in thought the same as green is not so bright as red. And so- of all the others. Frequently we have to express a difference between two objects which consists in the fact that, along with a certain resemblance, the one possesses qualities which the other does not. For example, the bat differs from the mouse in that the former has membranous appendages answering the purpose of wings, while the latter has not. The zebra differs from the horse in having a regu- larly striped skin. The whale differs from the most of the mammals in being an aquatic animal. In such comparisons as these it is not easy to adopt such an expression as will show the difference pre- dicated so clearly as in the former cases ; but the PSYCHOLOGY OF COGNITION. 275 thought is equally simple. There are two objects compared ; they are found to differ in a certain respect ; and the predication affirms that they do thus differ. And, as before, it is of no consequence which term of the relation comes first in the predi- cation ; the thought is the same, whatever be the particular mode of expression. § 179. Amongst the external relations of objects, both in respect of quantity and quality, that of resemblance is of great importance. It is in con- sequence of resemblance in certain respects that we classify objects together and constitute them a unity. It is in consequence of resemblance between objects that we draw inferences regarding them. We are not now concerned, however, with these uses of resemblance, but only with the nature and expression of the predication of resemblance. Let us study some examples : — This line is of the same length as that. These triangles are all equal -sided. This piece of lead loeighs two pounds. In the first and third of these examples there is a comparison of two objects, and a predication that they resemble one another; in the second the predication of resemblance has reference to several objects. When the terms related to one another in a predication of resem- blance are common names, there is always involved a comparison of several objects. For example, when we say, horses have four feet, we mean that all objects known by the term horse resemble one another in having four feet; here we predicate a T 2 CHAP. V. SECT. VI. External relation of resem- blance. 276 THE ELEMENTS OF THE CHAP. V. SECT. VI. relation of resemblance between all known or con- ceived individuals. And, as we said before, we imply that each borse bas four feet — an internal relation of co-existence. We often predicate resemblance between tbings wbicb are not exactly alike, but yet sufficiently alike to be classified together. Wben we say crimson is Wke scarlet, we mean not tbat tbey are exactly alike, but tbat tbey are the same hind of colour, and tbus distinguisbable from blue or green. Wben we say tbat the sheep resembles the deer, we mean to predicate resemblance only in certain respects, and if we state our meaning fully we will particularise tbe points of resemblance. The most of tbe resemblances wbicb are affirmed in predica- tion are only partial ; wben we affirm a complete resemblance we call it an identity, an equality, or some sucb name. Altbougb mental phenomena and material pheno- mena are thought to be entirely different in kind, yet they are frequently employed to illustrate one another. We speak of a lofty thought, thus implying a resemblance between the excellence of the thought and the altitude of some material object. We use light as a symbol of truth, or we say that light resembles tfuth, although there is in reality no resemblance whatever between them in themselves ; but in their results there is a resemblance since the appearance of light and the imparting of truth are both productive of knowledge in the mind. The relation between a symbol and that which is PSYCHOLOGY OF COGNITION. 277 symbolised, between a sign and that which is signified, is usually either a direct resemblance between the two things, or is accompanied by a resemblance amongst some of the circumstances or results connected with the two things. Sometimes, of course, this is not so, as in the case of the relation of a word to that which is denoted by it, where there is now often no resemblance, although there is reason to believe that originally the application of names was founded upon resemblance. § 180. The relations of simultaneity and suc- cession between mutually external objects are often the subjects of predication. As when we say : Milton was a contemporary of Cromwell ; John and James were class-fellows ; soldiers on parade keep step with one another. Or when we say : Chaucer preceded Spenser; after the flash of lightning a loud peal of thunder was heard ; a cause is always followed by its effect. It will be observed that the same relation of simultaneity or succession may be expressed in many different ways; and so far as thought is concerned, it is of no consequence by what words the relation is indicated, provided only it be indicated clearly. It will be observed, too, that the order in which the objects said to be related occur in the predication is immaterial. The sentence, Chaucer preceded Spenser, is the same as Spenser followed Chancer. The predication consists in assert- ing that a relation of succession exists between the two individuals, specifying which comes first. And, with reference to all the other examples, it will be CHA.P. V. SECT. VI. And of simulta- neity and succession. I 78 TEE ELEMENTS OF TEE CHAP. V. SECT. vr. Complex relations. admitted that tlie form of predication is unim- portant, provided only that it be clearly expressed what objects are related to one another and what is the relation between them. § 181. "We have hitherto confined ourselves as closely as possible to simple relations of difference, resemblance, simultaneity, and succession ; but in the great majority of predications the relations predicated are more or less complex ; and' often the relations implied in a predication are more numerous than those which are expressed. We may give examples of such complex relations. The judges in session, having tried the prisoner, agreed to find him guilty. In this complex predi- cation many relations are expressed and implied. The judges sit simultaneously upon the bench — a double relation of simultaneity — (1) amongst the judges; (2) between the judges and the bench. Having tried the prisoner, expresses a continuous process and implies a multitude of relations ; it also indicates that the action next Q,&serted followed the trial. Agreed to find him guilty j here is expressed a relation of agreement amongst the legal opinions of the judges, and a relation of difference between the action of the prisoner and some law. John struck the table. In this short sentence there are implied several relations. John and the table are in point of time simultaneous, in point of space contiguous ; and contiguity is itself the result of the combination of several relations. The stroke of John is an action, and therefore involves succession, f PSYCHOLOGY OF COGNITION. 279 viz., first the arm is raised; then it is gradually lowered, occupying successively different positions ; and then it comes into contact with the table pro- ducing, probably, a sensation of sound and certainly one of touch. Thus this simple sentence predicates a complex series of relations between two objects, John and the table. Many other examples might be given of complex relations being predicated between two or more objects; and it would be a useful exercise in the analysis of thought for the student to examine and separate the relations expressed or implied in the sentences which he reads. We think it will be found that all relations may ultimately be reduced to the four simple ones which we have described ; and that all predications may be shown to consist of an assertion or denial, that one or more of these relations exists between two or more objects or elements of knowledge or conception. § 182. We have given and illustrated what we believe is a correct exposition of that most impor- tant act of thought which we call predication. It now remains for us, from the stand-point which we have endeavoured to establish, to take a view of the current logical doctrines regarding the proposition. These doctrines are found in all the smaller text- books of logic ; and they find a place also in many of the more elaborate expositions of logical science. Not, however, in all, for we observe decided ten- dencies towards a departure from the traditional doctrine of the proposition in some modern writers 1 CHAP. V. SECT. VI. Logical doctrine of the pro- position. 28o TEE ELEMENTS OF THE CHAP. V. SECT. VI. of distinction. The leading features of the tradi- tional doctrine are the following : — Every proposition consists of two terms and the copula. The terms represent either concepts, classes or individual things ; and the copula serves as the connecting link between them. The words which constitute the copula are is and is notj according as the one term is to be affirmed or denied of the other. The first of the two terms, that about which the assertion is made, is called the subject ; the second, that which is asserted or denied of the first, is called the predicate. The subject of universal propositions is said to be distributed, or applied to all the things denoted by it ; that of particular propositions is not. The predicate of negative propositions, being altogether denied of all the individuals denoted by the subject, is distributed ; that of affirmative propositions is not. The copula is simply the sign of the relation of the two terms to one another ; it must not in- dicate the actual objective existence of the relation or the things related, nor the time when the rela- tion existed, nor the degree of certainty with which the assertion is made. All these accidental things must be included in the predicate. It is always possible, after limitations and changes in the predicate or copula, to convert propositions, that is, to put the predicate in place of the subject, and the subject in place of the predicate ; and this conversion, being rendered necessary by the laws of the syllogism, is an essential part of the doctrine PSYCHOLOGY OF COGNITION: 281 of the proposition. These are the principal points in the doctrine of the proposition regarding which writers upon logic are agreed ; but there are some points about which they are not agreed. They are not agreed as to the character of the predicate, some maintaining that it may be either denotative or connotative, others that it is connotative only. Those who believe that it may be denotative are not agreed as to its quantificatio7i, some holding that its extent should be explicitly stated in the proposition, others that its quantity should be determined by the ordinary rules. They are not agreed as to the meaning of the predication, some holding that the subject and predicate are simply asserted to be two different names of the same thing ; some that the predicate consists of attributes asserted of the subject ; and some that a relation of mutual co-existence or mutual inclusion or exclusion or congruence or confliction between the two terms is asserted. These differing views may be referred to in the following criticism ; but we shall give the most of our attention to the fore- going doctrines which are generally agreed upon. § 183. For the sake .of clearness we divide the subject of our criticism into the following parts : — (1) the terms of the proposition; (2) the rela- tion between these terms as expressed by the copula ; (3) the doctrine of distribution ; (4) the doctrine of conversion. (1.) In examining the terms of the proposi- tion our principal aim will be to ascertain whether CHAP. V. SECT. VI. Criticised. Terms. 282 THE ELEMENTS OF THE CHAP. V. SECT. VI. they correspond with the terms of predication. All predications_, we have already shown, con- sist of the assertion or denial that one or more objects or elements of knowledge or conception holds some specified relation to one or more other objects or elements of knowledge or conception. All predications have, therefore, two terms related to one another, and the assertion of some relation existing between them. And we have to inquire whether the terms of the proposition, as described by logicians, are the same as the terms of the predications which we consciously make. In every proposition, put into logical form, the predicate must comprehend all the elements of time, mode, and action, which are usually expressed by verbs and adjectives or adverbs. A few examples of propositions may form a good basis for our criticism. Horses are vertehrated. In this predication we affirm that each of a class of individual things possesses a certain quality or rather a certain part called a vertebra. Two objects of thought are before consciousness^ the image of a horse or horses and that of a vertebra; and. we affirm that the latter constitutes a part of the former. Thus we here assert an internal relation between the two terms ; and this internal relation is correctly expressed by the word are, Neither can there be any doubt that the terms of the proposition correspond to the terms of the conscious predication. But, suppose we modify the proposition, and assert that horses PSYCHOLOGY OF COGNITION. 283 helong to the class of vertehrata, it appears manifest that the predication which we make is quite different from the former one. Instead of predicating an internal relation we now predicate an external one; we assert that the class of horses are included in a much larger class of vertebrated animals. In the former proposition we do not think of any other animals except horses ; in this proposition we must think of other animals constituting a large class which includes horses. Now the scholastic doctrine of the proposition teaches that the predicate vertebrated is either connotative or denotative, and thus fails to distinguish between the two important kinds of predications above illustrated. This ambiguity in the meaning of the predicate in such propositions should not be recognised either in psychology or logic ; a predicate should mean either one thing or another, and the mode of expressing it should indicate which meaning is intended to be conveyed. Again, the sun illuminates the earth. In this predication we have in thought two objects which are the terms of the predication, and a certain relation existing between them, namely, that light proceeds from the first to the second and thus makes its surface visible to our eyes. This pro- position when put into logical form becomes, the sun is a-body-which-illuminates-the-earth. There the subject is the sun, and the predicate is a-body- which-illuminates-the-earthj i.e., the sun again, along with its relation to the earth. Now we CHAP. T. SECT. YI. 284 THE ELEMENTS OF TEE CHAP. V. SECT. VI. think that an appeal to consciousness will show clearly that the terms of this proposition, after beings put into the logical mould, do not correspond to the terms of the predication which we consciously make. The two objects which we think of as related are, plainly, the sun and the earth, not the sun and a-body-which-illuminates-the-earth. And it should, therefore, appear that the so-called logical form of this proposition has no foundation in the facts of consciousness. Gold is heavier than iron. Here we have the image of two substances before consciousness, and we assert a certain relation between them, namely^ that the one sub- stance is heavier than the other. But according to scholastic doctrine, the predicate of the pro- position is not irorij but heavier-than-iron. In this case also an appeal to consciousness will show that the second term of the predication, said to be in a certain relation to the first, does not correspond to the predicate of the logical proposition. Many other propositions might be adduced which would show that in the majority of cases the terms of the logically-formed proposition do not correspond to the terms of predication which are thought of in consciousness as related to one another. We have seen and admitted that, when a proposition expresses an internal relation of an object or class to some of its constituent parts or elements, the scholastic proposition may be correct and adequate. But, when external relations are predicated between objects, the logical propo- PSYCHOLOGY OF OOGmTION. 285 sition is quite inadequate to their expression ; the terms of the proposition do not correspond to the terras of the predication. § 184. (2.) We now consider the relation itself predicated between the objects or elements compared. Is this relation accurately expressed by the logical copula ? According to logical doctrine the relations expressed by the copula are those of genus, species, difference, property, and accident ; the predicate of a proposition may stand to the subject in any one of these relations. The two first of these are external relations ; the remaining three are internal. Now it is manifest that these relations have all reference to the process of classification; and it appears equally manifest that there are a multitude of other relations which form the subjects of predication that have no reference to classification whatever. When we say, for example, lightning precedes thunder J we do not mean to classify either lightning or thunder with any other phenomena whatever, nor have we in our mind any fact or process in- volved in classification. We do not mean that the fact of lightning preceding thunder is a differentia or a property or an accident of lightning, or that that fact distinguishes lightning from any other phenomenon. We mean simply to assert that a certain phenomenon, lightning, usually or always, is observed, before another phenomenon, thunder, heard. And this relation of antecedence or IS succession is certainly not expressed by the copula. Again, when we say, elephants are quadrupeds, CHAP. v. SECT. VI. The rela- tion predi- cated. 286 THE ELEMENTS OF THE CHAP. V. SECT. VI. these words properly express an internal relation between tlie animals spoken of^ and the quality- indicated by the predicate, the possession of four feet. But if this proposition is made to mean, elephants belong to the class of four-footed animals^ we have an external relation asserted, and the copula is not adequate to its unambiguous expression. In the same way it might be shown that all the other external relations of difference, resemblance, co-existence, and succession, and their various combinations, cannot be expressed by the copula. In fact, logicians do not pretend that they can, because they always consign the expression of these relations to the predicate, thus playing false with the phenomena of consciousness and producing monstrous forms of language. It appears then, that psychology offers no foundation for the doctrine that the copula is the only proper expression of the relation between the terms of predication ; and it might also be shown that there is no foundation in language. In many languages which are unquestionably expressive of thought there is found no such abstract verb as our is. And, even in our language, the substantive verb requires to be divested of all its meaning before it is fitted for logical use. ' Thus, it comes to be but an empty symbol, which differs from the symbols of mathe- matics, in that while each one of them has a definite meaning and represents a relation in thought, it is introduced for the purpose of putting aside the relations thought of which it cannot express. PSYCHOLOGY OF COGNITION. 287 CHAP. V. SECT. VI. DistrihU' tion of terms § 185. (3.) The doctrine of distribution is mani- festly founded upon facts connected with, classifi- cation. In the classes which we construct of organised individuals there are some qualities which are found in all the individuals denoted bj the class-name; there are other qualities, called acci- dental,, which are found in some individuals but not in others. We are able^ then, to predicate that all the individuals of the class possess the former kind of qualities, but only that some of them possess the latter kind of qualities. Again, when we predicate an external relation of certain objects, as when we say " birds belong to the class of oviparous animals," it is evident that we speak of all birds, but only of some oviparous animals ; and in this case the first term of the predication is distributed, the second not. But if we say " birds do not belong to the class of quadrupeds,^^ we speak of all birds and all quadrupeds, and assert that the one class is altogether excluded from the other. In this case both the terms of predication are distri- buted. Thus, when the first term of the relation de- notes a class, we indicate its distribution by prefixing the words all or some. When the second term denotes a class of greater extent than the first, we naturally indicate by the form of the predication whether we speak of all or some of the individuals belonging to it ; and at least the accurate expression of thought demands that the distribution of both the terms of the relation should be unambiguously expressed. These principles of distribution, properly applic- 288 THE ELEMENTS OF TEE CHAP. V. SECT. VI. M ot always thought of, and its laws not always a^ppUcahle. able only to terms wliicli denote classes^ are applied by logicians to all kinds of terms and all kinds of propositions. All universal propositions distribute their subject, while particulars do not. All negative propositions distribute their predicate^ while affirm- atives do not. Now if we had not a particular system to maintain, it might appear plain to us that the principles of distribution cannot be, without absurdity, applied to anything which does not admit of distribution or non-distribution. If we say, for example, '^the Duke of Wellington is a man,^' neither the first nor the second term of the predi- cation is a class-name as here used ; and were it not that we import from the process of classification, ideas foreign to the subject in hand, we should never think of the distribution either of '^ the Duke of Wellington'' or '*aman.'' Logicians, however, must reduce every proposition to the normal form, and so they make this a universal affirmation and write it '^ all of the Duke of Wellington is one of the class — man." Again, if we take a proposition expressive of an internal relation, we shall see that the rules of distribution are not applicable. In the proposition "roses are sweet-smelling,'' the first term of the predication -may denote either all or some roses according to our opinion of their odour. But the second term " sweet-smelling " expresses a quality possessed by roses, and when we speak of a quality, we surely mean the whole of the quality, and it seems absurd to say that the name of the quality is either PSYCHOLOGY OF GOGNITIOK. distributed or not distributed ; if we do so, we apply a distinction to it which is plainly not applicable. This objection, however, is got over by changing the predicate and thus forming another j^roposition, thus : — '^ Hoses are sweet-smelling flowers," meaning "roses belong to the class of sweet-smelling flowers." But it is surely objectionable, in order to get a proposition into such a form that the rules CHAP. V. SECT. VI. riiiX:^-- distribution may be applied to it, to change/ihp: Off,^^^^^ relation predicated in it. This proposition ill its' first form asserts an internal relation to the secon^ , ^4, >'*. term of which the principles of distribution do nok; S^O^ I. * apply ; and in order to bring it into such a form that ^Si;^^^ iPTI .O. the second term may be tested by the laws of dis- tribution, it is changed so as to express an external relation. Surely a correct psychology offers no foundation for such a procedure. It could be easily shown that the laws of dis- tribution are inapplicable to many other kinds of propositions, of which we may give the following as examples : — The line A is equal to B ; the sun is brighter than the moon ; the dawn precedes the day ; silver is not so valuable as gold ; the Prince of Wales shot an elephant ; stars bespangle the sky. In all these propositions relations are predicated between two or more objects, the relation being expressed with perfect clearness, and in none of them can we say, with any degree of appropriateness, that either term of the relation is distributed or non-distributed ; the distinction is inapplicable and foreign to the subject. 590 TEE ELEMENTS OF THE CHAP. V. SECT. VI. Conver- sion. Our conclusion, founded upon an examination of the meaning of propositions, may be tlius stated. Only tliose terms wliicli denote classes of things can be properly spoken of as being totally or partially distributed ; the names of single qualities or objects should not be quantified ; but wherever a class-name admitting of quantification should, for the sake of clearness, have its quantity made known, we have a right to insist that its quantity should be explicitly stated. This conclusion is founded upon the great law of expression, — what- ever is contained in thought should be accurately expressed in words ; whatever is not contained in thought should not be expressed in words. We do not thinh of the quality affirmed in the predicate of a proposition as being applicable to many or few objects; we should not therefore quantify it. But where the subject or predicate is a class-name, wholly or partially distributed in tliouglity its dis- tribution should be expressed in language. § 186. (4.) We now come to the doctrine of conversion. For the sake of the transposition of terms required by the syllogism, it is considered by logicians of importance, that all propositions should be convertible ; and there are certain well-known laws laid down for their conversion. The laws of distribution receive their full importance only in connection with conversion ; as the importance of the laws of conversion is seen only in relation to the syllogism. The great law of conversion is, — that no term should be distributed in the converted PSYCHOLOGY OF COGNITION. 291 proposition, which, was undistributed in the original one. And by the application of this law it is found that universal negative and particular negative pro- positions may be converted without any change of quantity or quality, that the universal affirmative can be converted by limiting the quantity of the predicate, and that the particular negative may be simply converted after changing its quality, that is, changing it into a particular affirmative by trans- ferring the sign of negation from the copula to the predicate. Now, if we examine predications as they are naturally expressed, there does not seem to be any objection to the order of the terms being changed provided there is a sufficient reason for the change. If we say "whales are included in the class mammals,^' we mean the same as "the class mammals includes whales.''^ If we say "thunder succeeds lightning,^' we are understood no better than if we say " lightning precedes thunder.^' The predication " gold is heavier than silver,'^ expresses the same relation as '^ silver is lighter than gold.'' The sentence " John strikes the table,'' is, as far as thought is concerned, exactly the same as "the table is struck by John." In short, if we express any relation in a predication, the laws of thought and language require nothing more than clear- ness and accuracy in the expression; and it is a matter of indifference which term of the relation .comes first. But, if we examine the conversions of logically u 2 CHAP. V. SECT. VI. 292 THE ELEMENTS OF THE CHAP. y. SECT. VI. Consii't' ency of predica- tions. formed propositions , we cannot so easily admit their legitimacy. The proposition "roses are red/' becomes, in the haads of logicians, when converted, " some red things are roses/' The simple sentence "thunder succeeds lightning'' is metamorphosed into "a class of things succeeding lightning is thunder." The monstrous forms of language which require to be introduced for the purpose of convert- ing the majority of logically moulded propositions appear to afford a strong reason for doubting the legitimacy of the process. But, as we have seen, the principal objection does not lie against trans- posing the terms of a predication, but rather against the changes to which naturally expressed predica- tions must be subjected, in order to bring them into the so-called logical form. § 187. There are certain things connected with the mutual consistency of predications to which we now turn attention. Predications having the same subject may be related to one another in a variety of ways. The subject may be taken in its whole extent or only in part of its extent ; the predicate may be affirmed or may be denied of the subject. Conabining these different forms we get the con- trary, contradictory, and subaltern relations of pre- dications pointed out in works of logic. And it is necessary in combining predications together in a course of reasoning that consistency between the different predications made must be maintained. To be consistent is to avoid contradiction, and a simple inspection of two simple propositions will FSYGHOLOGY OF COGNITION. 293 show whether they are contradictory or consistent. If we can predicate either of the whole or of some of the class A that they are B, it would be incon- sistent to predicate that all are not B. If we can predicate of the whole or of some of the class A that they are not B, it would be inconsistent to predicate that all are B. But we may consistently predicate of some of the class A that they are B, and of others that they are not B, provided that B is not an essential quality. Further, inconsistency may arise from attaching predicates which are in their nature inconsistent with one another to the same subject ; as, for example : The figure A is a square. The figure A is a triangle. But there may often be an apparent inconsistency arising from the attachment of incongruous predicates to the same subject, which is found to be not real. The incongruous predications may be truly made of different parts of the thing denoted by the subject. Inconsistencies between propositions are usually concealed by placing them wide apart in the dis- course, by complicating them with many other pro- positions not clearly arranged, by the use of am- biguous terms, and in other ways. The avoidance and the detection of inconsistencies cannot be assisted to any great extent by special rules, but depends chiefly upon the clearness of intellectual perception, the correct and un-ambiguous use of language, and the avoidance of complexities and confusion, both in the individual parts and the general arrangement of the discourse in hand. CHAP. V. SECT. VI. 294 TBE ELEMENTS OF THE CHAP. V. SECT. VII. Law of excluded middle. Import- ance of systematic knowledge. § 188. Witli reference to the mutual relations of predications it is frequently of importance to place a doubtful question in sucli a form that either one or the other of two answers must be accepted as true. This is done by means of contradictory opposition. If " all A is B/^ it is perfectly certain that the predication '^ some A is not B " is false. If the latter is true, the former must be false. And there is no middle predication possible. The prin- ciple according to which we affirm that of two contradictory propositions the one must be true and the other false,, is called the " Law of Excluded Middle.''^ In the application of this Law we are, as a rule, not supposed to know which of the con- tradictory extremes is true, because if we knew, the proposal of the alternative would be useless. The law is frequently very useful in controversial argu- ment, enabling one to place before an opponent two contradictory propositions, the one or the other of which he must admit to be true, and thus involve him in what is called a dilemma. Section VII. seasoning simulating infeeence. § 189. It is of great importance to human wel- fare that the knowledge which men possess should be clearly arranged in their minds, that the different elements of that knowledge which have a natural relation to one another should be brought together, and that ignorance and confusion should give place PSYCHOLOGY OF GOGNITIOK. 295 to systematic science. There may be possessed by a man a great deal of knowledge wliicli can be of no use whatever in consequence of inability to bring together into one view related facts, to see their significance, and to give them their proper place in the system of knowledge. Thus the knowledge which many possess, although very extensive, is a perfect chaos, a jumble of confusion, and of no prac- tical use in the guidance of life. To reason with a man frequently means nothing more than to point out the relation between different things which he already knows, and thus bring into order what was before confusion. There are to every man hundreds of ^^ open secrets,^^ facts related in particular ways which relations he cannot see, and it is the function of what is commonly called reasoning to convert this chaos of confused facts into a cosmos of order and harmony, so that men may see clearly what has always been under their eyes, and understand clearly the relations and significance of what they have blindly perceived. This discovery or pointing out of the true relations between things already known is not what we mean by Inference, although it very of ten assumes the form in which true inference is naturally expressed. It is made also still more closely to resemble inference by being frequently forced by logicians into the artificial forms of the syllogism, which is assumed to be the universal type of reason- ing. To make clear the true psychological nature of the process which we are describing we shall examine some typical examples of it. CHAP. V. SECT. VII. 296 THE ELEMENTS OF TEE CHAP. V. SECT. VII. Erroneous classifica- tions. § 190. We observe, in the first place, that mistakes are very apt to be made in the classifying of the objects with which we are acquainted, and a great I deal of what passes for reasoning is simply an I attempt to assign objects to their proper classes. There are many popular classifications which are erroneous in themselves and lead to other errors, and an important duty of scientific men is to correct these \ erroneous classifications. From our study of the i formation of classes we can understand the manner I in which a correct classification is to be effected and I an erroneous one is to be avoided. It is only by the ! possession of the Essentia of a class, or at least of j some universal characteristic of a class, that any I object is to be referred to that class. Suppose, for I example, that a person ignorant of natural history I were to assert that whales belong to the class fish, his mistake would be corrected by informing him that whales do not possess the essential qualities of the class, fish, — they are not water-breathing or j oviparous. Supposing him to know the principle I of classification, he would immediately see that his j predication regarding whales was incorrect. And i upon discovering or being informed further that whales are viviparous and suckle their young, and i that these are the essential qualities of a class called mammal y he would at once refer them to that class. Thus in order to effect a correct classification it is necessary to know by observation or instruction (1) what are the essential or characteristic qualities of j some class in question ; and (2) whether the object in PSYCHOLOGY OF COGNITION. 297 question possesses or does not possess these qualities or characteristics. Knowing these two things^ the mind at once refers or does not refer the object in question to the specified class, § 191. The preceding example which illustrates the process of classification, when put by logicians into their favourite form of the syllogism, appears as follows : — All fishes are oviparous animals : Whales are not oviparous animals, .'. Whales are not fishes. We have already pointed out that the predicates of propositions, as a rule, are connotative,* and that, therefore, it is psychologically incorrect to give them extensive quantity. The first two of these propositions therefore ought to be : — All fishes are oviparous : Whales are not oviparous. But these two propositions being taken together, it becomes impossible to classify whales with fishes, and consequently the mind asserts, — Whales are not contained in the class, fish . Now it must be observed that this is not an inference in the proper sense of that term. The so-called conclusion is directly seen the moment that the essential qualities of whales and fishes become known. If a boy have before him a number of marbles, and mixed up with them a number of hazel-nuts, he sees at a glance that the latter should not be classified with the former. The * i.e. When the propositions relate to some facts of classifi- cation. CHAP. V. SECT. VII. The syllO' ijism not the best form for collecting false clas- sifications. 298 THE ELEMENTS OF THE CHAP. V. SECT. vir. Incon- gruous predicates. only difference between this case and the previous one is, that the qualities which make it impossible to classify the two sets of objects together are more obvious. § 192. Again, it is a principle of consistency be- tween predications that two incongruous predicates cannot be attached to the same subject. To assert '^ the figure A is a square/^ and " the figure A is a circle," is a mental impossibility; and in practice the only difficulty is to see what predicates are incongruous, many predicates being- frequently sup- posed to be incongruous which are not really so, and vice-versa. Now much of so-called reasoning is nothing more than an attempt to show the congruity or incongruity of predicates. Suppose, for example, we take the proposition, "the sensualist, being enslaved by his appetites, cannot be free.^' When placed before our minds in this form there appears no difficulty in seeing immediately that " slavery to appetites " and " freedom " are incongruous, and can- not be predicated of the same individual. Logicians, however, must express it in the form of a syllogism, No one is free who is enslaved by his appetites : The sensualist is enslaved by his appetites, .'. No sensualist is free. We leave it to the reader to decide which is the most intelligible form. Sometimes predicates are thought to be incon- gruous which are not really so, and the way in which this error can be most easily corrected is to point out an instance in which the apparently incongruous- PSYCHOLOGY OF COGNITION. 299 predicates are plainly seen to be consistent. It might, for example, be supposed that certain modes of conduct which are consistent with holiness cannot at the same time be inexpedient. This hasty judg- ment would at once be seen to be incorrect by point- ing out some special circumstances in which it would be highly inexpedient to do some things which, after all, were quite consistent with holiness. But logicians would think that the simple pointing out of an instance to the contrary would not be enough to correct the error, and they would probably express themselves in some such way as this : — Some practices which the Divine Law allows are in some circumstances inexpedient ; All such practices are in themselves consistent with holiness : . • . Some things in themselves consistent with holiness are in some circumstances inexpedient. § 193. Many other examples might be given of the manner in which erroneous classifications are corrected, and the consistency or inconsistency of attributes or predicates determined. In popular language these processes are called reasoning, and logicians, basing much of their science upon this popular phraseology, do violence to psychology as well as to grammar by forcing them into the form of syllogisms. But in truth they are nothing more than the bringing together of related facts, and the percep- tion of the relations between them. This being done, the so-called conclusion is not an unknown thing ; it is directly seen. And the preliminary process is only the bringing of facts together so that it may be CHAP. V. SECT. VII. Popular reasoning often not inference. 30O TEE ELEMENTS OF THE CHAP. V. SECT. VIII. Character of in- ference. seen. Notwithstanding that this arrangement and harmonising of things known does not partake of the nature of inference, it is most important to human advancement and welfare that it should be well done. But the details of its accomplishment cannot be con- trolled by any rules more special than those general principles of classification and consistency to which we have referred. The work must depend chiefly upon the practical good sense and insight of the individuals who devote themselves to it. Section VIII. INFERENCE. § 194. We have already seen that Inference is one of the two grounds upon which predication rests, the other being Intuition. And the difference between the two is this, that whereas in intuition we see directly the relation which is asserted in the predi- cation, as well as the objects between which the relation exists, an inference asserts a relation which is not directly known, but which follows more or less immediately from what is so known. In our study of perception we have had under our notice many instances of inference. When we see an orange before us, we infer, or at least we may do so, that if we cut open the skin we shall see and touch certain small rounded elongated bodies called seeds. The reason why we infer this is that all the oranges which we have previously opened have had seeds of this description within them. And, judging from PSYCHOLOGY OF COGNITION. 301 our past experience, we infer that this particular orange which we see before us has seeds within it. Now the nature of this simple inference is essentially the same as of that wonderful illustration of the power of reason exhibited in the discovery of Neptune. An inference is a mental assertion j regarding the existence and relations of something | not directly known, or, it maybe, of something which we cannot directly know. And on the other hand, all inferences must be founded upon something which we do know, either directly or indirectly. § 195. The Law of Sufficient Eeason gives an important caution regarding the drawing of infer- ences. " Infer nothing/^ it tells us, '^ without a Sufficient Reason.^' The statement of this law implies that inferences cannot be made arbitrarily, that before the mind can draw an inference there must be some antecedent reason to justify it. This principle is a universally binding one. But when the law tells us that the reason must be Sufficient, there is left a very wide margin for doubt and differ- ence. All who draw inferences, and they include the whole human race, think that they have reasons sufficient for the inferences which they draw. But subsequent reflection, or the judgment of othei-s, frequently pronounces the reasons to be insufficient. There are, therefore, valid and invalid grounds of an inference. The ground alleged may not be sufficient to support it; or, looking at it from the other side, the inference may be drawn by the mind when there is no reason sufficient to make it legitimate. Thus, CHAP. V. SECT. VII f. SujUcient Reason. 502 THE ELEMENTS OF THE Intuitive basis of inference. CHAP. V. altliougli this Law expresses a most important caution against hasty and baseless inferences, it must be further defined and explained before it can be prac- tically useful in enabling us to determine what inferences are legitimate. § 196. As Intuition is the original source of our knowledge, we naturally look to it for the first grounds upon which inferences may be built. Knowledge which is given to us in intuition must lie at the foundation of all knowledge and belief ; and if in the superstructure errors are found, their source is probably to be found in some of the false inferences which have been drawn. Now we have seen that in intuition there are made known to us either indivi- dual objects or the relations between them. And we have seen that these relations may be of sequence in its various forms, of co-existence, and of likeness and unlikeness in their various forms and degrees. But all inferences are expressed in predications; and all predications are the assertion that two objects of thought exist in some relation to one another. Hence it is primarily to the relations given to us in intuition that we are to look as the ground of our assertion of those other relations which are predicated in our inferences. From certain relations which we know, we infer the existence of certain relations not directly intuited. Thus, having known that a certain relation exists between the objects of thought, A and B, and between B and C, we infer that a certain relation exists between A and C. In this case the objects A and C Chiefly in- tuited re- lations. PSYCHOLOGY OF COGNITION, 303 are directly known, but the relation is not. Again, having known that a certain relation exists between A and B, there comes within our knowledge an object like B : we infer that there exists in relation to this second B an object like A. Thus we have apparently two forms of inference : we infer the existence of a relation between two objects both of which are known ; and we infer the existence of the unknown term of a relation, together with its relation, to some object which we know. § 197. A few particular illustrations will make more clear the abstract statements of the last para- graph. We have before us three straight ABC lines. A, B, C. We are able to compare A with B, and B with C, and find that A is equal to B, and B to C. We infer, without directly perceiving, that A is equal to C. The relations compared are in this case so simple, and the inference presents itself to the mind with such force, that it is usually expressed in mathematical works in the form of an d A B C axiom, or self-evident proposition. | *' Things which are equal to the same thing are equal to one another/' But it is none the less truly an inference, although one regarding which there cannot be in the mind the slightest doubt. If, again, we take four lines, A, B, C, D, of which A is equal to B, D is double of A, and C is double of B, we infer without hesitation that C is equal to D. Here the CHAP. V. SECT. VIII. Tivo forms of in- ference. Illustra- tions of in- ference of first form. 304 THE ELEMENTS OF THE CHAP, Y. SECT. VIII. Illustra- tion of in- ference of second form. relations between A. and D, B and C are known, a certain ratio of length, A being one-half of B, and B of C. Thus A and B being equal, and the relation between A and D being equal to the relation between B and C, we infer a relation of equality between D and C. This inference is expressed in the mathematical axiom, "Doubles of equals are equal/^ Similar remarks might be made with reference to the majority of the mathematical axioms. They are inferences immediately based upon intuitions ; their objects are simple and per- fectly free from variable conditions, and there con- sequently is not the slightest room for doubt as to the legitimacy of the inferences. Inferences of this simple kind have all the certainty of intuitions; but yet they are not intuitions, unless we assume some other distinction between inferences and intuitions than that which we have given. They have been called axioms, or principles of mathematical thought^ but this is perfectly incorrect; they are particular examples of inferences, so simple and unavoidable that the mind can never fail to draw them when occasion requires. The mind universally recognises the respective equality of two lines or figures to a third as a sufficient reason for the inference that the two are equal to one another. § 198. We now study an example of an inference in which the existence of an unknown term of a re- lation is inferred. By a long course of investigation scientific men had come to the conclusion that all material bodies in the universe exert upon one PSYCHOLOGY OF COGNITION. 305 another an influence resulting in motion, and called the Force of Attraction. Illustrations of this force are seen in the falling of bodies to the earth, the motions of the moon and planets, and many other phenomena. By means of many accurate observa- tions, the laws of force, and of the consequent motion of bodies, had been calculated ; and so pre- cisely had this been done that astronomers could predict exactly the position of any of the planetary bodies amongst the stars at any given moment. Now it had been observed that the positions of Jupiter and Saturn at certain times were not exactly what they ought to be ; there was a certain variation in their motions which could not be accounted for by the attraction of any of the known heavenly bodies. This variation, therefore, was a phenomenon to be accounted for ; it might be the result of a mistake in the statement of the laws of motion ; it might be the result of inaccurate obser- vations j or it might be the result of the attraction of some unknown body beyond the orbits of Jupiter and Saturn. The first of these possibilities could not be admitted, because the laws of motion had been tested in innumerable instances and had never before failed. The second was rejected, because the observations had been taken with the utmost precision by skilled observers and accurate instru- ments. The only inference, therefore, which ap- peared to have a sufficient reason was the third, that there was some hitherto unknown body beyond Saturn which caused the variation. And CHAP. V. SECT. VIII. 3o6 THE JELmiENTS OF THE CHAP. V. SECT. VIII. Another illustra- tion. the success of astronomers in discovering this bodj proved the accuracy of the inference. Now here the process of reasoning appears capable of analysis into the following elements : A great bodj^, the sun, exerts a powerful influence over a number of smaller bodies, the planets ; these also exert a similar, but, in degree, a less influence over one another ; the result of this is that certain compli- cated relations in space exist between the sun and surrounding planets. Here we have — (1) a number of bodies; and (2) a certain regularity of their motion in space. But a new phenomenon appears ; this regularity is in a particular case interrupted : a cause of this interruption there must be, and, so far, no cause is known ; the only inference which can be drawn is, that there is some hitherto un- known cause, and that the unknown cause is similar to the causes of motion already known — the forces of the sun and planetary bodies. Thus we have here — (1) a known relation between certain known bodies and their motions ; (2) a motion, or variation of motion, not related to, that is, not caused by, these known bodies; and (3) the inference of the other term of relation, the unknown planet, to account for the variation. § 199. Again, in our consciousness, we are aware of two great classes of phenomena, described as voluntary activities and passive states. The former we are conscious of producing by our own effort ; the latter we are powerless to produce or to anni- hilate. As an example of the former we may PSYCHOLOGY OF COGNITION. 307 instance muscular sensations and the sounds of our own voice ; as an example of the latter, sounds heard, but not produced, by ourselves, and colours which we see. Now, with reference to our voluntary activities, we are conscious of a certain forth-putting of energy in their production ; it makes no difference whether we are aware of the different links which connect the conscious effort with the result or not ; we perceive an invariable relation of sequence between — (1) the conscious effort ; and (2) the com- plex of sensations which we regard as its result. But, in the case of passive states, as, say colours, we are conscious of sensations, but the other term of the relation is wanting ; these sensations we know that we have not produced ; we therefore infer the other term of the relation, a cause not ourselves the productive efficiency of which accounts for the sensations. Analysing this process we have — (1) a perceived relation between A {conscious effort), and B {sensations) ; (2) a knowledge of B^ {similar sensations) ; (3) the inference of A^ {a7i objective cause more or less similar to A). And, be it remembered, the objective A, is not an aggregate of other sensa- tions collected somehow together in a group, because every one of these sensations requires to be accounted for in the way that we have now indicated. The objective inferred term of the relation is therefore unknown ; we think of it as a cause adequate to the production of the perceived effect, and its nature can be learned, and only learned imperfectly by the aid of hypothesis, X 2 CHAP. V. SECT. VIII. 3o8 THE ELEMENTS OF THE CHAP. V. SECT. VIII. Inferred relation between unTcnown ipowers. § 200. We take still anotlier illustration of inference, in which there is inferred to exist a cer- tain relation between unknown hypothetical powers. Many years ago Count Kumford made experiments regarding the connection between motion and heat.* He found that the friction of two bodies always produced a certain amount of heat; and that the motion of any body, whenever it was arrested or hindered, resulted in heat. Hence he concluded that heat, as it exists in bodies, is a form of motion. Since his time many experiments and observations have been made regarding the relations of motion, heat, light, electricity, and other natural forces, and it has been clearly established that they are all convertible into one another. But by inference like that which we have examined in the last paragraph, there is some objective Force or cause which has a relation to each one of these phenomena, and the discovery of the correlation of motion, heat, light, &c., does not result in the inference that the one phenomenon is the cause of the other. Intimate relations are perceived to exist between motion, heat and light ; the inference is that the unknown causes of these phenomena, hitherto supposed different, are in reality identical. The accompanying diagram illustrates the dif- ference of views produced by the experiments referred to. Originally a different cause, F Cal L, is inferred to account for each of the phenomena m, h, c ; * This discovery is described in a paper published in the " Transactions of the Royal Society for 1798." PSYCHOLOGY OF COGNITIOK 309 but observation sbows certain nu- merous and intimate relations between m, h, c ; it is consequently inferred tbat F Cal L^ are really one, as represented in tbe united lines of the second diagram. And tbus also the relations between m, h, c are inferred to depend upon the community of the Force F with reference to them all.* §201. There are many inferences which have a close relation to classification. We have observed, for example, that all vertebrated animals which fly through the air by means of true wings are oviparous as far as we have been able to discover. These observations collected together in a proposition, are thus expressed, " Birds are oviparous." Having formulated our observations in this proposition, and having come across a class of animals agreeing in essential particulars with the known class birds, we infer regarding the newly-discovered class that they are oviparous. We do this, although we have not seen the eggs or the nest ; and a naturalist would not be satisfied with his observations of a new species of bird until he was able to verify his inference by the examination of the nest and the habits of the bird in the rearing of its young. Now an analysis of this process gives us the following elements : (1) A class of animals grouped together by the possession * F, force; cal, caloric; L, light; m, motion; h, heat ; c, colour. CHAP. V. SECT. VIII. 310 THE ELEMENTS OF TEE CHAP. V. SECT. VIII. Classifica- tion of ob- jects of inference. of certain characteristics^ this class, as far as we have observed, having in particular a certain predicable attribute, oviparous ; (2) a certain number of animals observed to possess some of the essential qualities of the preceding class ; and (3) the inference that the attribute, oviparous, may- be predicated of them. § 202. The preceding illustrations of inference will enable us to advance to the discussion of some important questions regarding it. But, before doing so, we shall offer and explain a classification of the spheres of thought in respect to which inferences are drawn. (I.) We have, in the first place, inferences regard- ing the relations of particular parts of Space and Time, and also regarding that which is a result of a combination of Space and Time^ Motion. Space and time, we have seen, are the forms of external intuition, and motion is known to us as in terms of space and time. And when the lines, figures, and other dimensions of space, time, and motion are made the subjects of inference, abstraction is made from all particular content of intuition; the inference has reference only to the elements of the forms. (II.) Inferences are drawn, in the second place, regarding certain Forces or powers which are not known to us directly as phenomena, and which, indeed, cannot be so known. The inferences have reference to the nature, relations, and laws of these powers, as well as to their connection with the PSYCHOLOGY OF COGNITION. ir phenomena througli wliich they manifest them- selves. (III.) There is a third class of inferences_, having reference to the existence and relations of Phe- nomena. These inferences determine our belief of the existence of phenomena not directly known in relation to certain other phenomena which we do know. But they have not reference merely to the present time ; they extend to the occurrence of past events,, in which case they depend upon historical evidence ; they reach forward also to the future, constituting prevision, expectation, or probability, according to their degree of certainty. Before, however, we consider these classes of inferences, we must give more minute attention to the determining reasons upon which inference rests. Section IX. DETEEMINING GEOUND OP INPEKENCE. § 202. In the preceding section we analysed certain particular examples of inference for the purpose of gaining a general knowledge of the process. We saw that inference is a mental assertion made, without immediate knowledge, regarding some relation be- tween known objects; or, regarding the existence and relation to known objects, of some object or power not directly known. We have seen that in certain cases the same inferences are uniformly drawn by all men, whereas, in other cases there is room for doubt CHAP. V. SECT. IX. Question proposed. 312 TRE ELEMENTS OF THE and difference ; and tliat in all cases there is some ground upon wMch. tlie inference is based. Our task, now, is to examine into tlie nature of this ground. It is admitted that all inferences form a part of our conscious experience ; and the question is, What is it that determines this experience ? In any given case of inference, why is it that we infer so-and-so, and not otherwise ? When, for example, we see two lines each equal to a third line, why do we infer that they are equal to one another ? When we seethe motion of any body without us taking place, why do we infer that there is some force impelling it ? When we see any seed, in germinating, putting forth a pair of leaves instead of a single one, why do we infer that the future plant or tree will grow by the addition of annual layers of woody tissue upon the oufcside sur- face ? In other words, what is the sufficient reason of any inference which makes that inference necessary or legitimate ? § 203. The question of the preceding paragraph may be discussed with reference to the three classes of inferences described in the last section. We make inferences regarding the forms of the objects of knowledge, space, time and motion ; the /o?res which operate in nature around us; and the phenomena which present themselves, or are capable of doing so, to oursenses or consciousness. In connection with the first of these classes of inference, a great deal of dis- cussion has arisen regarding the nature of the basis upon which demonstration rests. Certain axioms, such as, '' Things which are equal to the same thing PSYGHOLOGY OF COGNITION. 313 pare equal to one another," are generally placed at the beginning of mathematical works, and assumed to be self-evident. And we have now to consider the nature of those axioms. One class of thinkers tells us that they are a priori judgments, not founded upon anything more simple and original than themselves. Being self-evident, and necessary, and universal they must be original intuitions of the mind. But to this opinion, as it is generally expressed, there is a prima facie objection. The axiom quoted above is general in its application ; it applies to all things, of whatever nature they may be, which are equal to one another. And we may assume it for certain, that a proposition of this kind is not formed until after one or more particular examples of it have been known. This axiom as well as all the others, has been generalised, and the question is, What is the nature of the parti- cular mental acts from which it has been drawn ? Now, taking the particular axiom referred to, it is manifest that the single mental act from which it is generalised must be either an intuition or an infer- ence. A is equal to B ; C is equal to B ; therefore A is equal to C. This is the particular form of the general axiom, and must have |9recec?e(^ the general axiom in historical order. In this form the mental act appears to be an inference. A is not directly seen to be equal to C, but both A and C are seen to be equal to B ; and the inference is drawn. But it has been held that this apparent inference is ori- ginally an intuition ; that we are not able to predicate that A is equal to C until after we have compared CHAP. V. SECT. IX. A priori theory. Empirical theory. 314 THU ELEMENTS OF THE CHAP. V. SECT. IX. Axiom general- ised from a particular necessary inference. them directly together ; and that having seen several instances in which A and 0^ being each equal to a third thing, B, they are found to be equal to one another^ we generalise the axiom as above. Accord- ing to this view, the axiom is generalised from ex- perience, and the particular experiences from which it is generalised are experiences,, not of inference^ but of intuitions brought about by voluntary and artificial means. This explanation is not satisfactory. It has the appearance of being simply invented without any other reason than that it is capable of partially ex- plaining the axiom. There is no evidence whatever that such artificial trials of equality as those postu- lated are ever made for the purpose indicated. And if they were actually made, the generalised axiom resulting could not have that degree of certainty which it has, unless this certainty had some other ground than the alleged experience. § 204. We must therefore examine the view which considers the particular act from which the general axiom is generalised as an act of inference. There is a comparison of two things with a third thing, and the inference that the two things, being equal to the third, are equal to one another. But we must remem- ber that the third thing, which is the medium of comparison between the two others, may not be an external object, but may be a part of our own organ- ism. And we know, from the evidence of language, that the original medium of comparison between the lengths or other spatial relations of external objects is some part of our organism. In many languages, PSYGEOLOGY OF GOGNITION. 315 and perhaps in every language, the original standards of measure are particular parts of the body. A foot, a hand^s breadth, a span, a cubit, a fathom, are terms of measurement which, from being so uni- versally used in English, and having so many analogues amongst other nations, lead to the con- clusion that the parts of the body implied in them afford to men the primary standards of comparison with respect to the relative extension of objects. Now, if we analyze this primary mode of comparison into its psychological elements, we appear to get the following : The eye and the hand of a primitive man having been trained to work together, he applies the hand, outstretched to its farthest limits, to a short object ; he sees that the tip of the finger and the point of the thumb coincide with the ends of the thing to be measured ; he has, in other words, a certain complex act of perception, the result of which is that he pronounces the object examined a span in length. At another place and time, he applies the same test to another object, with the same result ; he remembers that the preceding complex act of perception was essentially similar to this one ; and he infers that the length of the two objects is the same. Now, be it observed, this inference is not one which he might make or not, as he pleased. He is compelled to make it; he cannot draw any different inference ; and it is this necessity of the particular inference in hand which gives the manifest universality to the axiom gene- ralised from it. And as we see what is the nature CHAP. V. SECT. IX. 3i6 THE ELEMENTS OF THE CHAP. V. SECT, IX. Artificial standard of com- parison. of the mental act whicli precedes the inference, we can see also how the inference is necessary. A complex act of perception is compared with a remembered act_, and seen to be similar ; the fidelity of each act of perception to the reality of nature being assumed, it follows at once that the objects are equal. Thus, a perception of similarity in the mental acts by which two objects are known to us is the ground of our inferring their equality. But in making this inference it is assumed (1) that each of the acts gives us a true knowledge of the spatial relations of each object, and (2) that these spatial relations have a true, and to our minds, independent existence. § 205. If we were to examine the other axioms which deal with the relations of equality, inequality or proportion of extended bodies, we should find that the psychological basis of them all is a percep- tion of likeness or unlikeness between the sensations of eye and muscle, by the combination of which the relative dimensions of the bodies become known to But it is soon found that by a comparison of us. these sensations without any artificial assistance correct results are not obtained ; and moreover, the natural measures of length, the hand or the foot, are not exactly th'e same in different individuals. Hence, for the sake of greater accuracy, and of having a common standard, artificial measures made of wood or metal are invented. But even after this has been done, the psychological basis of inference is not changed. We apply a foot-rule to a body to dis- PSYCHOLOGY OF COGNITION. 317 cover its dimensions ; but this is only an artificial contrivance to enable us more accurately to compare our perception of its spatial relations with that of another body, or to compare our measurement with that of other individuals. There is thus recognised the fact that objective standards of spatial dimensions are more reliable than subjective or organic ones. § 206. The axioms of equality and inequality which are usually applied to space may be applied to time also. The natural measures of time are — (1) our sensations considered as succeeding one another; and (2) our perception of certain bodies which are found to recur at regular intervals. In- ferences regarding the temporal relations of events must be founded upon comparison of the psychologi- cal acts by which these relations are estimated. But, as a rule, inferences regarding time are combined with the relations of space, as when we infer regarding the time which it will take a certain body to pass through a certain space. But before any inference can be drawn it must be shown or assumed that the motion of the body is either uniform or varies ac- cording to certain known laws. This being granted, inferences can be drawn with perfect certainty. With reference to all reasonings regarding rela- tions of space and time, either separately or com- bined, it has been noticed that there is a remarkable degree of certainty and precision connected with them. It is also found that in simple cases no other inference is possible than that which is drawn. This precision and necessity of inference are to be CHAP. V. SECT. IX. Axioms applied to time and motion. Certainty of in- ference accounted for. 3i8 THB JELEMENT8 OF THE CHAP. V. SECT. IX. accounted for by tlie nature of tlie circumstances in wMcli tlie inference is made ; A and B are two di- mensions of space or time, eack made known to us in the acts of perception a and b. In consciousness we compare a and b together, O the one being actual, the other remembered ; we see their likeness, and we believe that each mental act is a true tran- O script of the objective quantity. This being so, the inference of the equality of A and B follows of necessity, simply because there is no other inference which has any foundation whatever. And even if, by direct comparison, we found that A and B were not exactly equal ; we would not conclude that our inference was erroneous, but that some element of error had entered into a- or 5 or the comparison of them. Thus although it may be quite true that the generalised axioms regarding space, time, and motion are founded upon experience of particular inferences; it is also true that there is something which determines that this experience must be thus and not otherwise. There are certain relations between our conscious intuitions and the quantities of space and time given in them, which afford a basis for the inferences which we draw, and afford no basis for any other inference. No other inference is possible to us, and hence we call these inferences necessary. § 207. "We now pass on to consider the ground of PSYGHOLOGY OF GOGNITION. 319 inferences regarding forces not directly known. We liave already in §§ 198-99 given a description of the kind of inferences to which we refer. There is a certain conscious effort exerted which is followed by a certain result ; an event similar to this result occurs, but without any effort on our part ; we infer an objective power of which it is the result. And the question is, upon what ground do we make this inference ? Before considering this question, we must, in the first place, postulate that there is given to us in consciousness a knowledge of power. Muscular sensations are the subjective side of that of which muscular effort is the objective. And muscular power is not known to us as a relation between muscular sensations and some result. Neither is power known to us as a relation between any mental events and their consequents. Simple succession can never give us the idea of power. But in the consciousness of muscular sensation, the objective side of which is muscular effort, we have a direct knowledge of power, and when the organism is in a healthy state, we are able, by means of other sensations, to know the results of the forth-putting of this power. Thus our knowledge of causal effi- ciency is intuitive, although it no doubt takes a little time and experience to connect muscular efforts with their proper results. § 208. Having now got the two terms of the first relation, conscious effort and ifcs result^ another object, a passive sensation, comes before conscious- ness. We know that it is not caused by us, because CHAP. V. SECT. IX. Inferences regarding unknown forces. Knowledge of -power intuitive. Analysis of inferential process. 320 THE ELEMENTS OF THE CHAP. V. SECT. IX. we have been conscious of no forth-putting of effort in its production. But why do we seek for its cause at all ? Some people would answer that it is because we know d priori that every event must have a cause. Perhaps this statement may be resolved into the simple fact that we are reasoning animals, that by our birth as human beings we inherit a tendency to search after the relations of things, and that by the same birth-right we are never satisfied until we have discovered the relations and the causes of the things we know. If this is a correct interpretation of the law we admit its truth. Now comes the final question — what is the ground of our inference that the known passive sensation is caused oA^ by an unknown objective power ? The relation between A and B is known ; B^ is similar to B, in as far as it is an BO oB^ object of consciousness ; the inference of a subjective cause is excluded by the conditions of the case ; the only possible inference, therefore, is that of an objective cause, A^ holding the same relation to B^ which A holds to B. It must be admitted, however, that this inference is usually accompanied by other circumstances which give it form. A^ is usually connected with a group of qualities consti- tuting an external object. But into this group of qualities the subjective idea of power is invariably projected from which it can never be eliminated except by the unnatural attempts of a phenomenal psychology. The child attributes personality and PSYCHOLOGY OF COGNITION. 321 power to the stick whicli has given it pain, and begins to beat it. The untutored savage thinks a spiritual power into every object of Nature. § 209. The inference of some objective power for the events which we ourselves do not produce is compulsory ; but there is a great room for doubt and difference as to the nature of that power. Men primarily inferred the existence of innumerable spirits; others have postulated a common substratum, matter ; others infer a universal mind ; others again conclude that there are various powers mutually correlated, which are but forms of a universal Force. As this is not a work upon metaphysics, we do not feel called upon to discuss these conflicting theories. But we may point out that inferences regarding the nature and laws of the unknown cause or causes of phenomena must, from the nature of the case, be hypothetical. And the best that we can do is to adopt that hypothesis which, to our minds, most fully explains the phenomena. It is therefore upon a careful study of phenomena and their mutual rela- tions that we should build our hypothetical inferences, taking care that no phenomena be overlooked or placed out of their proper relations. It would take us far beyond our limits to discuss this subject as it should be discussed. Some have held that because in these matters the absolute certainty of mathe- matical demonstration or of intuition is unattainable, they ought to be excluded from the sphere of science altogether. This, however, would be an arbitrary limitation o£ the sphere of science against which the CHAP. V. SECT. IX. Hypo- thetical nature of inferred causes. 322 THE ELEMENTS OF TEE CHAP. V. SECT. IX. Inferences as to existence and rela- tions of pheno- mena. actual practice of scientific men is a standing protest. Hypothesis fingo, Newton to the contrary notwith- standing, is the practical language of the man of science, even in cases when there appears to be no hope of his hypothesis ever being directly verified.* § 210. We now come to the consideration of in- ferences regarding the existence and relations of phenomenal objects. Illustrations of these inferences have already been given in § 200. . . . We have seen also that they may be generally divided into two classes, in the first of which we infer some relation to exist between phenomena which we know ; and in the second we infer the existence of a phenomenon not directly known, and holding a certain relation to another phenomenon, or set of phenomena, known to exist. And the question to be decided is, what is the ground of the inferences we draw in each of these cases ? Now it must be observed that in drawing these inferences there is a great room for error. Thousands of instances might be pointed out in which false relations have been supposed to exist between phenomena. It must be admitted, then, that inferences may be drawn which are not in conformity with the truth of nature. And therefore we must consider, not the ground of infer- ence in general, but the ground of correct inference. But in this it is implied that amongst phenomena there exist certain objective relations which may be known by us or not, and if our inferences are not the * It maybe fairly maintained, however, that the sphere indicated. above belongs rather to metaphysical than to physical science. PSYCHOLOGY OF COGNITION. 323 true expression of these objective relations they are not correct. We observe, for example, tbat night always precedes day, but if we were to infer from this uniformity of sequence that a causal relation exists between them, our inference would be erroneous, as there are various reasons for our concluding that this is not the true relation. In drawing inferences, therefore, it is necessary to disting between those relations of things which are dental and those which are essential. In order this properly, we must have recourse to those of induction which Bacon and his followers have formulated. The object of these laws is to enable us to distinguish between accidental and essential co-existences and sequences. Those relations which are of the latter class are thought to have some connection with the cause of the phenomena. And those inferences are thought to be correct which connect together phenomena between which there is objectively a causal relation, or a relation de- pending upon identity of causation. The relation, for example, between the lowering of the tempera- ture of the atmosphere and the deposition of dew is an essential one, and the inference which con- nected the one with the other was correct, although, perhaps, it is not proper to call this the causal relation. It is correct also to infer that animals which we have discovered to have some of the essential characteristics of birds are oviparous, because we have learned that there is an essential objective connection between these characteristics Y 2 CHAP. V. SECT. IX. 324 THE ELEMENTS OF THE CHAP. V. SECT. X. Contro- versy re- gardingthe syllogism. and that quality which we infer. Thus it appears that before we can be satisfied with inferences regarding phenomena, the subjective connection which we form must be recognised as being the counterpart of essential objective relations between things. Inferences are not concerned merely with the relations of ideas, but also, and principally, with the objective connections of real things. Section X. THE fOEM OF INFEEENCE. § 211. Is there any general form according to which the mind acts in the drawing of inferences^ and, if so, what is that form ? This question has given rise to a good deal of controversy, especially with reference to the claims of the syllogism to be considered the universal type of reasoning. It has been asserted, on the one hand, that, if all the mental acts and principles which are involved in the drawing of inferences be explicitly stated in lan- guage, the statement will assume the form of a syllogism. It has been held, on the other, that there are many instances of reasoning in which the mental process cannot, without the greatest violence, be put into the form of a syllogism, although it is admitted that many kinds of reasoning do naturally assume that form. Before discussing this question we must examine the nature of the syllogism. According to the accounts of the syllogism, which we find in logical treatises, syllogism is inference which is PSYCHOLOGY OF COGNITION. 325 drawn from the general, from some proposition or judgment whicli is generally true. There are three terms in every syllogism, two of which, the minor and major terms, are the subject and predicate of the conclusion; while the third, the middle term, is found in each of the premises, and is the medium by which the terms of the conclusion are compared together. All these terms are held to be the names of concepts having a greater or less denotation and connotation. And in the syllogism there is a com- parison of the denotation or the connotation of the minor or major terms, with the denotation or con- notation of the middle term. This comparison has for its object to determine whether the one term contains the other, either wholly or partially, that is whether the denotation or the connotation of the one term includes, wholly or partially, that of the other. Now, in order to determine the character of the claims of the syllogism to be considered the only type of reasoning, we shall have to consider — (1) whether inference proceeds only from the general; (2) whether nothing but concepts are the elements of inference; and (3) whether the rela- tion of containing and contained is the only relation regarding which we infer. § 212. The first of these points has been prac- tically decided by us already. We have seen that some of the so-called mathematical axioms are generalised from particulars, and consequently that particular inferences are drawn before the gene- ralised axioms are formed. We have seen, also. CHAP. SECT. Inferences may he drawn from par- ticulars. 326 THE ELEMENTS OF THE CHAP. V. SECT. X. Inference does not regard con- cepts hut objects. that in perception an objective cause of our passive states is inferred to exist from the consciousness of some particular sensation uncaused by our conscious effort. Now, the only ground upon which inferences of this kind can be expressed in the form of a syllogism is, that there is an d priori principle latent in the mind which serves for the major premiss of the syllogism. Against this theory we have already adduced objections.* And the over- throw of this theory renders it impossible to put into syllogistic form the inferences referred to. There are, then, particular kinds of inference which do not proceed from general judgments, but from particular objects of knowledge. § 213. With reference to the second point, it is maintained by some that inference has to do pri- marily with concepts and the relations of concepts. But, as individual objects undoubtedly form sub- jects of reasoning, concepts are taken to be not merely the representations of the qualities of a class, but also of an individual. To this doctrine, that reasoning refers exclusively, or even principally, to mental representations, we must take exception. Every mental representation which we make, either of an individual object or of a class, has significance to us only as related to the real objects of which it is a concept. When we make use of the term ma7i, we mean not our mental representation of human attributes, but the real external objects possessing human qualities which we denote by that name. * § 203.. P8YGE0L0GY OF COGNITION. 327 And when we say "man is mortal/' we mean fhat the real beings whom we call men will all die. Thus, if we are to depend upon what consciousness reveals to us, inference has reference primarily not to con- cepts, but to the real objects or classes of which the concepts are more or less complete representations. And the predication of the inference asserts or denies a certain relation to exist between these objects. § 214 What is this relation ? Is it only that of the container and the contained, the mutual inclusion or exclusion, in whole or in part, of two objects of thought ? A reference to particular cases of in- ference will soon decide the question. From a comparison of certain angles and triangles we infer — " The angles at the base of an isosceles triangle are equal to one another/' This is certainly not a relation of inclusion, either total or partial. From a variety of considerations we infer that the rapid cooling of the atmosphere is the cause of the depo- sition of dew. It would be difficult to put this inference into the stereotyped form. From many experiences we infer, when we see smoke, that com- bustion is going on somewhere near at hand. The relation expressed in this inference is certainly not one of inclusion. In short, since inferences consist of predications, and since predications assert any of the relations which may be perceived in intuition as existing between two objects of thought, it is manifest that reasoning must occupy itself with all these relations. This the syllogism, in its present form. CHAP. V. SECT. X. Relations predicated in in- ference. 328 THE ELEMENTS OF THE CHAP. V. SECT. X. as to form of reason- ing post- poned. does not do; and hence, in its present form, we maintain that it is the type of only a particular, although important^ variety of the reasoning process. § 215. Having decided against the claims of the syllogism to be the universal form of reasoning, we might inquire if there is any other form which can legitimately make similar claims. But we shall be better able to consider this question after we have studied more fully different reasoning processes with which we are familiar. We have already divided the sphere of inference into the subordinate sphere concerned about (1) space and time, with their various divisions and combinations, (2) the non- phenomenal causes of things sensible, and (3) the existence and relations of phenomena. But in these different spheres the grounds upon which the infer- ences rest may vary greatly in their nature and extent, and the inferences themselves may have every variety of probability attached to them. Upon the principle of advancing from the more concrete and particular to the more abstract and general varieties of inference, the following appears to be a suitable division : (1) Inferences regarding the occurrence of particular events, depending upon evidence or testimony ; (2) Inference founded upon analogy and induction, either particular or expressed in a less or more certain general law ; (3) Deductive inferences from general principles. PSYCHOLOGY OF COGNITION. 329 Section XI. evidence; induction; deduction. § 216. It is frequently necessary, in the common affairs of life, to form opinions regarding the occur- rence or non-occurrence of events, or the nature of alleged facts which have not come under our own observation. These opinions are of the nature of inference depending upon what is called Evidence. We may divide the facts or events regarding which evidence is taken into two general classes : (1) con- temporary facts or events alleged to exist or occur in our own time, within the memory of persons now living ; and (2) historical facts or events alleged to exist or occur in some past generation. The evi- dence on which inferences regarding the first of these classes of facts are based is most frequently human testimony, although, in the absence of that^ or when it is not thought completely trustworthy, a great variety of circumstantial evidence may be resorted to. Inferences regarding historical facts or events depend upon tradition, historical records, the existence of commemorative monuments and other things. We shall refer to certain principles by which we are guided in drawing inferences in each of these cases. § 217. The most direct evidence of contemporary occurrences which we have not ourselves observed is the testimony of others. But in receiving the testi- mony of others there are various things which must CHAP. V. SECT. XI. Inference depending upon evi- dence. Regarding contempo- rary facts. 330 THE ELEMENTS OF THE CHAP. V. SECT. XI. Testimony. Circum- stantial evidence. be considered before placing implicit reliance upon it. We have found by experience that some persons are not truthful in relating what they have seen or heard ; that some persons are incapable of accurate observation^ mixing up their own fancies or pre- judices with the facts which they are observing ; that some persons are very liable to be governed by interested motives so as deliberately to misrepresent in their own favour the facts which they relate. These and other considerations have led to the establishment of various legal customs connected with the taking of evidence, such as the imposition of an oath, cross- questioning, and others. For the purpose of correcting human testimony it is found also that a variety of circumstantial evidence is of very great importance. The majority of the alleged occurrences regarding which inferences a-re to be drawn leave some permanent marks or traces behind them which may be afterwards observed, and these, in the hands of a skilful interpreter, frequently form the basis of important and true conclusions. There is, however, great difference in the skill of different persons in discovering the significance of permanent marks or signs. The barbarous tribes of an uncultivated country usually show remarkable acuteness in reading the meaning of the traces of past events ; while the natural or acquired skill of the professional detective is often equally wonderful.* * For a specimen of this acuteness and skill the reader is referred to Edgar A. Poe's remarkable description, " The Murders in the Rue Morgue." PSYCHOLOGY OF COGNITION. 331 § 218. In determining the value of evidence, tliere are, generally speaking, two things to be considered ; the nature of the evidence itself, and especially the character of the persons by whom it is given, and the nature of the fact testified to. The mind fre- quently refuses assent to alleged facts in consequence of the improbability of these facts occurring. When a person is well acquainted with a particular class of facts, he knows pretty accurately what phenomena of that kind are likely in given circumstances to occur, and he refuses to accept the testimony of ignorant observers if their testimony contradicts his expectations. The antecedent probability or impro- bability of particular occurrences taking place exerts a great influence upon our estimate of the value of the evidence adduced in their favour. This predis- position to believe or to disbelieve alleged occurrences varies greatly in different minds, and depends greatly upon the kinds of experience with which the mind has been familiar. If, for example, an expert in physical science is informed of the occurrence of certain phenomena, such as table-rapping and other things said to be performed by spiritual agents, he feels a strong predisposition to attribute the pheno- mena either to deliberate deception on the part of some one concerned, or to the operation of some of the natural forces with which he has already become acquainted. This predisposition, although a valuable safeguard against indiscriminate credulity, often proves a hindrance to the discovery of truth by pre- venting competent men from undertaking a careful CHAP. V. SECT. yi. Value of evidence. Predis- position to receive or reject ew- dence. 332 TUB ELEMENTS OF TEE CHAP. V. SECT. XI. Regarding historical events. examination of tlie evidence upon whicli alleged occurrences rest. With reference to every human being it may be said^ " There are more things in heaven and earth than are dreamt of in your philo- sophy," and consequently in the mind of every human being there is likely to be a predisposition to reject the evidence of some things which are actually true. § 219. We now proceed to the consideration of the nature of the evidence upon which inferences regarding the occurrence of historical events are based. And it is manifest that, as a rule, this evidence cannot be so satisfactory as that of contemporary occurrences. The witnesses of historical events are dead ; they cannot be put upon their oath ; they cannot be cross-questioned ; the whole of that searching process of eliciting from unwilling, or stupid, or inconsistent witnesses the true state of the case, with which we are familiar in modern courts of law, must be foregone or, at best, very imperfectly performed. The evidence upon which our inferences are built consists chiefly of written documtents containing either descriptions of or allusions to the events concerning which we are inquiring. The accounts of these wHtten documents may be confirmed or modified by the discovery of monumental figures or inscriptions, or other remains, and by the perpetua- tion amongst the people of traditions or customs apparently depending upon the alleged events. In examining the written documents, the most important PSYCHOLOGY OF COGNITION. 333 points whicli should be ascertained are : the persons by whom these documents were first written ; the time when they wrote and the opportunities which they enjoyed of becoming accurately acquainted with the events which they describe; the cha- racter of the writers for intelligence and truthfulness, and especially the feelings by which they might be influenced in writing their accounts. These points having been determined, either with certainty or with a greater or less degree of probability, there will remain to subject the documents themselves to a criticism something analogous to the cross- questioning of legal courts. This criticism will have for its object the obtaining of a true and complete view of the occurrences described, by bringing together disjointed accounts, harmonising, where possible, apparent inconsistencies or incongruities, and, in short, bringing into a consistent unity the great variety of unsystematically-arranged details of events, and character, and life which the docu- ments present ; but it may possibly result in the con- clusion that such a unity is unattainable. Examples of this historical criticism are to be found in modern inquiries regarding the lives and labours of Homer, and Plato, and other ancient worthies, and especially in the modern criticism of the Christian Scriptures. § 220. Asinthetreatmentof the evidence adduced in favour of the occurrence of contemporary alleged events people are under the influence of a predispo- sition to believe or disbelieve, according to the view CHAP. V. SECT. XI. Prejudices hoiv to he treated. 334 TEE ELmiENTS OF THE CHAP. V. SECT. XI. Analogy. which thev are likely to take of the probability of the events occurring, so there is a similar predisposi- tion with reference to historical events. From our own experience and from the recorded experience of others, we form opinions as to what may reasonably be expected to take place in particular circumstances, and these opinions influence our minds very strongly in our treatment of historical evidence. These pre- formed opinions, or prejudices, as they are called, it is impossible to get rid of, simply because it is impossible to annihilate our own past mental history and the influence which it has had in forming our present character. But it is possible for us to understand that our prejudices may prevent us from attaining to a knowledge of the truth concerning which we inquire, and it is possible for us so far to overcome our prejudices as to admit in particular cases that what appears antecedently improbable to us may nevertheless be true. The antecedent im- probability, therefore, of any event which is not merely ridiculous and absurd, should not prevent any one from carefully examining the evidence upon which it rests. § 221. We now proceed to the consideration of those inferences which are drawn from particular facts or relations, and which are usually called inductive. One of the commonest forms of this is analogy. Two objects agree in certain particulars, and it is inferred or expected that they will agree in others. A child sees a tin rattle and hears the rattling noise which it makes when shaken ; when PSYCHOLOGY OF COGNITION. 335 he sees sometliing afterwards at all resembling tlie rattle lie expects from analogy that it will rattle when shaken. In this case the expectation or inference appears to be founded upon the principle of association ; when two or more qualities have appeared once or repeatedly in connection with one another, the subsequent appearance of one of them or of a similar one, leads to the expectation that the others are capable of realisation. This rudimentary example of analogy assumes a higher type as knowledge increases and we begin to learn essential resemblances and differences of things. In physical science inferences founded upon analogy have led to most important conclusions or discoveries. It was by analogy that Newton drew his inference regarding the cause of the motions of the heavenly bodies. It was an apparent analogy which led Franklin first to infer, and afterwards directly to ascertain the identity of lightning and electricity. Innumerable examples of inference founded upon analogy are presented in the science of language. The philologist finds in Latin or Greek a word the original root of which he cannot discover in these languages; a word analogous in form and meaning is found in some other Arian language, as the Gothic or Sanskrit ; and in these latter languages the root, perhaps, is found, and thence inferred to be the original form of the Latin or Greek word in question. § 222. It is manifest that the analogy between two objects which may form the basis of a reliable inference cannot be a simple resemblance of some CHAP. V. SECT. XI. Analogy of accidental qualities not the ground of inference. z?>^ THE ELEMENTS OF TEE CHAP. V. SECT. XI. Induction. Syllogistic theory. accidental qualities. There must be a resemblance between qualities whicli are found to be essential before the inference from analogy can be drawn. A shark swims in the sea, and so does a whale ; but this accidental resemblance would never form the basis of analogical inference to any reasonable mind. The qualities of two bodies which are to form the ground-work of analogical inference must be essential^ or be connected with essential qualities of the bodies in question ; and also the quality which is inferred must have some essential connection with the other qualities from whose resemblance the inference is drawn. Unless there is a recognised objective connection the inference is baseless. § 223. Induction proper has for its basis an observed relation of phenomena, or the elements of phenomena, in a greater or less number of cases ; and the inference asserts what will take place in all similar cases. Inductive inference affirms regarding all instances of a particular kind what is observed to be true of a certain number of instances of that kind. As far as has been observed, all animals of the bovine kind chew their cud; but naturalists assert that this is true universally. As far as has been observed, all material bodies have weight ; but physicists admit no exception to the universality of the quality. Thus in Induction the inference goes beyond the observed facts, and in order that this extension of the inference may be valid, there must be some foundation for it. Let us see what this foundation is. Those who are not satisfied until they have put PSYCHOLOGY OF COGNITION. 337 every kind of reasoning into the form of a syllogism tell us that inductive inference is a syllogism with the major premises suppressed; and further, that the suppressed major is the principle that '^Nature is uniform in her operations." Newton's induction then would appear as follows : — "What nature does sometimes she does always; Xatnre makes this, that, and the other body to gravitate. . ■ . Nature makes all bodies to gravitate." Even although we allowed that all inductive infer- ences are naturally expressed in the form of a syllogism^ it seems inconceivable that such a crude, indefinite, and practically worthless major premiss as the one cited should have retained its position so long. As an example of its uselessness we give the following : — "Nature is uniform in her operations ; This, that, and the other animal of the class mammalia live on dry land. . • . All mammalia live on dry land." Of course it will be at once answered that this is an accidental quality. Very good; then let a prin- ciple be adopted which will recognise the distinction between essential and accidental qualities, which the principle above named does not pretend to do. § 224. What, then, is the foundation upon which inductive inference rests ? It is certainly not a mere subjective association, because that is quite as inca- pable of distinguishing between the essential and the accidental as the principle above referred to. There must, therefore, be some recognised objective con- CHAP. V. SECT. XI. Founda- tion of inducticn. 338 THE ELEMENTS OF THE CHAP. V. SECT. XI. The per- manence of species. nection in things wliich. forms the basis of induction regarding them. We have ah-eady seen* that in the formation of a class or species to which we apply a common name, we separate by abstraction some of the qualities from the others, according as we think them essential or not to the constitution of the species. The Essentia of the species com- prises all these qualities without which the species would not be what it is ; this essentia, although formed by abstraction, and therefore determined by us, has a permanent objective existence in the various individuals from which abstraction has been made. Now, as we have determined such and such qualities to constitute the species, it is manifest that wherever any individuals of the species exist, these qualities must be found ; if any other indi- viduals are found destitute of one or more of these qualities, we simply say that they do not belong to that species, or we constitute them into a sub- ordinate variety of the species, or we enlarge the definition of the species so as to include them, as the case may be. Thus, in drawing the inferences which result in classification, we assume the per- manence and immutability of natural species, and having determined by careful examination and comparison ' what are the essential qualities which constitute the species, we infer with confidence that all individuals belonging to the species possess these qualities. And if any individuals, apparently members of the species, are found destitute of its * §§ 157-163. i PSYCHOLOGY OF COGNITION-. 339 essential qualities, we either relax tlie terms of admission into the species, or treat the refractory individuals to scientific excommunication. § 225. There are some cases in which a single instance may lead to a universal induction. For example, when, having applied a common measure to two lines, we infer their equality, the mind advances at once to the general maxim, — ^things which are equal to the same thing are equal to one another. The nature of the original inference accounts for the immediacy and universality of the induced pro- position. The mind cannot help but draw the inference in any particular case, as we have seen ;* neither can it conceive any circumstances in which, from the same basis, a different inference could be reached; hence the universal axiom is accepted without hesitation. There are other inferences of induction which appear to be made with equal readiness. Two ivory balls of equal size are sus- pended by strings of equal length ; they are made to fall down equal arcs of a circle at the same time and strike against one another ; the force of the one counteracts that of the other. Hence the generalised principle, '^ Action and re-action are equal and oppo- site.^^ Now, the particular mental act from which this law is generalised is manifestly an inference. We see two bodies of equal sizes moving through equal spaces in equal times ; and we observe that the motion of each is equally arrested by the concussion. * § 206. CHAP. V. SECT. XI. Axioms general- ised from a single inference. 340 THE ELEMENTS OF THE CHAP. V. SECT. XI. Differen t kinds of induction. The inference pronounces that the force which each ball exerts is exactly met and counteracted by that of the other ball. As we know nothing about ob- jective force, except as an inference to account for otherwise unaccountable phenomena, so we know nothing about the laws of forces, except as inferred from the relations of observed phenomena. But the inference is one which cannot be avoided, simply because there is no foundation for any other inference. And since the particular inference is an unavoidable one, the induced principle is seen, without doubt, to be of universal application. § 226. Thus we see that all general laws are the result of induction, as well as those general proposi- tions which express the characteristics of classes of objects. But there are inductions and inductions. Some inductions, as those regarding the relations of mathematical magnitudes, and the laws of forces, are founded upon particular inferences, these inferences being unavoidable in the present condition of things. Other inductions are founded upon the perceived re- lations of certain qualities which we have determined, by observation and comparison, to be essential to the constitution of particular classes. Thus, in all cases of induction there must be recognised the existence of a certain' established objective order of things, and our inductions are only an expression in language of what we believe to be essential relations of this objective order. If our inductions accurately cor- respond to the objective order, we say that they are true ; if not, not. PSYOEOLOGY OF COGNITION. 341 § 227. We are now brought to tlie study of the last form of inference, the deductive. Here the mind passes ia reasoning from the general or universal to the particular. Having already known something to be true of a whole class of things, we are able to affirm it to be true of every individual of the class. Familiar illustrations of the deductive process are seen in the application of the general laws of natural forces to particular cases, and in inferences regardi the qualities of particular individuals of a class f: our knowledge of the essential constituents of class. The astronomer, having determined the la of the motion of some particular planet, is able to infer with precision the particular point in the hea- vens which it Avill occupy at any particular moment. The chemist, having determined the laws of the com- bination of particular elements, is able to predict the result in any special case. The naturalist, having discovered the universal characteristics of some species of animals or plants, expects with certainty to find these characteristics in every new specimen. The natural form in which inference of this kind is thrown is, no doubt, the syllogism. And the princi- pal value of the syllogism is to state in an explicit methodical form those deductive inferences at which the mind arrives, frequently without any conscious reference to the major premiss at all. § 228. In order that the deductive inference may be thoroughly reliable, the major premiss must be an expression of some essential objective order or law of things. If, for example, the maj or premiss of a syllo- CHAP. V. SECT. XI. Deduction. r/y ^iriK. Certainty of infer- ence de- pends up- on major premiss. THE ELEMENTS OF THE CHAP. V. SECT. XII. Hypo- thetical Inference. gism be *' All swans are white/' an inference from, that, with reference to the colour of any particular swans, hitherto unseen, could not be made with perfect certainty. We could never feel certain but that birds might be found possessing all the essential characteristics of swans, but which were of some other colour. Whereas, if we have for our major premiss, "All cows ruminate,^' the inference with reference to particular animals of the species is certain, because the predication of the major premiss expresses an essential condition of the class. Deductive inferences which have for their object some accidental quality or state of things can never amount to more than a probability. The probability of the inference is the consequence of the want of certainty which characterises the major premiss. And that want of certainty arises either from the accidental nature of the relation which is predicated in the premiss, or from our partial ignorance regarding it. Section XII. CONCLUSION, § 229. By way of summing up the conclusions at which we have arrived in the preceding sections, we may first point out the different kinds of inferences which we draw. One of the most important of these is the Hypothetical Inference,^ by the object of which * This, of course, is altogether different from the hypothetical form of the syllogism. PSYGHOLOGY OF COGNITION. 343 we account for the existence of known phenomena. The existence of any particular sensation is accounted for by inferring some objective hypothetical power. The existence of a foot-print upon the sand is ac- counted for by the supposition that S. man walked along the sand some time previous. The statements of a historical writer are accounted for by the in- ference that the events which he describes actually occurred. Any particular phenomenon or complex series of phenomena being given, we account for its existence and character by inferring hypothetically some antecedent cause sufficient to account for it. In many cases we may never be able to verify the inference by direct knowledge ; but it matters not, the inference must be made, nevertheless, to satisfy that insatiable craving after a knowledge of the causes of things which is our birth-right as rational beings. In many other cases the hypothetical inference may be verified, as in the discovery of the planet Neptune, and in the discovery of certain new metals which had been inferred to account for peculiar phenomena in the spectroscope. In cases where the hypothetical inference cannot be verified by direct observation, various degrees of probability, or even a practical certainty, may be obtained by considering the degree of completeness with which the particular inference accounts for the phenomena, and the absence of a foundation for any other inference. § 230. The Particidar Inference founded upon siihjective association is very familiar. Two or more CHAP. V. SECT. XII. Particular Inference. 344 THE ELEMENTS OF THE CHAP. V. SECT. XII. Inductive Inference. objects of knowledge Laving occurred together a few or several times, there is formed an expectation that where one of them appears the others maybe looked for. The occurrence of these objects together leads the mind to suppose that there is some objective connection between them, and this supposition forms the ground of the inference. When this supposition is converted into actual knowledge, and the con- nection between the two associated phenomena is ascertained, the inference is no longer problematical but acquires the character of a certainty. The Par- ticular Inference founded upon a comparison of simple Intuitions is also characterised by certainty from the very first. When we infer that the lines A and B, being each equal to C, are equal to one another, there is no other inference which we could possibly draw. § 231. The Inductive Inference J founded upon uni- formity of experience, never amounts to more than a high degree of probability. But it is not therefore to be despised, because in many cases nothing but a certain degree of probability is attainable. And in the practical concerns of life probability is our usual guide. The Inductive Inference, founded upon a Icnoivledge of the essential relations of the things concerned, partakes of the same amount of certainty as the knowledge on which it is founded. Illustrations of this are seen in the axioms of mathematics and of natural forces, and in the inductive generalisations regarding natural orders and species. PSYCHOLOGY OF COGNITIOK 345 The Deductive Inference is based upon some general principle, and rests for its conformity to truth upon the assumed trutli of tlie principle from wliicli it starts. The general propositions in which the dif- ferent species of induction terminate are the starting-point from which deduction proceeds in reverse order. § 232. With reference to the form in which inferences should be expressed, it appears to be a matter of very little consequence. All knowledge may be resolved into the knowledge of objects and their relations, and all inferences are concerned about the existence and relations of objects, or the occurrence of events, not directly known, and about the relations of known objects. Every inference referring to an object or a relation not directly known must be founded upon some relation which is known either by intuition or some preceding in- ference. And, in the arrangement of the different elements of the reasoning process, the grand re- quisite is that the mind should be able to pass readily, and without hesitation, from the ground to the inference. To secure this requisite is sometimes very difficult in consequence of the obscurity or com- plexity of the subject with which we may be dealing. And we need not expect to get much assistance from the formulae of the logician. Difficulties in thinking are not to be overcome by any formal rules which may be laid down, but by careful and per- severing attention to the subject, and sometimes by a natural genius with which some people are 2 A CHAP. V. SECT. XII. Deductive inference. Conclu- sion. 346 ELJSMEJSfTS OF PSYCHOLOGY OF COGNITIOm CHAP. V. SECT. XII. peculiarly endowed. Consistency and truth are tbe two things which we should strive after in our thoughts. The former has reference to the mutual relations of the different elements of our knowledge or belief; the latter to the conformity of our thoughts with the essential order of things. For the satisfaction of that rational nature, the pheno- mena of which we have been studying, there is demanded not merely an elaborate and consistent system of doctrine which may after all be a mere airy castle, but also and especially a certain con- fidence that what we think is a counterpart and expression of that which is- YOOABULAEY OF PHILOSOPHICAL TEEMS. As this Manual of Psychology may be used by some who are not accustomed to reading philosophical works, the Author has deemed it advisable to append a vocabulary of terms which are not likely to be familiar to such readers, hoping thereby to make the work more iiseful. The terms explained are mostly found in the present work and widely employed in books upon this and kindred subjects. Abstract. — To withdraw the attention from certain qualities or elements of any object of knowledge with a view of fastening it upon other elements or qualities. For example, when we attend to the colour of an object we abstract the mind from its form and weight. Abstracted. — The quality or element to which the attention is thus turned is usually said to be abstracted from the others, although, properly speaking, it is the mind which is abstracted from them. Abstraction. — The quality or element of the objects of our knowledge singled out from the others for special attention is often called an abstraction. Various qualities or elements of knowledge may be singled out from a number of objects, and these qualities, which are the same or similar, joined together in a mental image which is called an abstraction. Accident. — in forming classes of objects there are found some qualities which are present in some of the objects but absent in others ; these are called accidents. 2 A 2 348 VOCAJBULABY OF PHILOSOPHICAL TERMS. Accidental. — A quality or element of objects or of classes which is thus sometimes present and sometimes absent is said to be accidental, to distinguish it from those elements which, being universally present, are called essential. Affinity. — A term expressive of a variety of relations be- tween objects of our knowledge. Objects which are related to one another, as a cause and effect, parts and a whole, sign and thing signified, and so on, have a natural connection with one another, so that when one is thought of the others naturally come before the mind. Such objects are said to have mutual affinity. Analogous. — When two things are similar in some of their qualities or effects, although entirely different in others, they are said to be analogous. The fin of a fish, for example, is analogous to the wing of a bird, or the leg of a horse. Analogy. — A resemblance between two or more objects in some particular qualities or actions is called an analogy. Analyse. — when we separate any object of knowledge into the simple elements of which it is made up we analyse it. Analysis. — The act or process of separating objects of know- ledge into their constituent elements. A careful analysis of any complex product is a most important condition of obtaining a thorough understanding of it. Antecedent. — When one object of knowledge comes into the mind before another it is called the antecedent. Appetite. — The desire which we have to satisfy those wants which originate in some condition of our physical organism, such as hunger or thirst, is called an appetite. A posteriori. — When the progress of knowledge or reason- ing is from effects or consequents to causes, or conditions, or antecedents, we are said to proceed d posteriori. A priori. — Knowledge or thought is d priori when we pro- ceed from causes or conditions to effects or consequents. Assertion. — When the mind affirms that any object of knowledge exists, or that any relation, simple or complex, exists between two or more objects, an assertion is made. Assertion expressed in words is predication. Association. — The mental union which binds together two or more objects of knowledge, so that when the one appears before the mind the others follow, is called association. Assumption. — At the beginning of any course of thought or discussion certain things must be taken for granted as known ; these constitute the basis of argument or assumption, and, if put into the form of a syllogism, will be found in the premises. VOCABULARY OF PHILOSOPHIGAL TEEMS. 349 Audible. — That whicli is capable of affecting the organ of hearing so as to produce a sound is said to be audible. Being. — The most abstract of all mental products. When the mind withdraws its attention from all the qualities by which objects are known and thinks only of the fact that things are or exist, it reaches, as nearly as possible, to the conception of a Being. To think of Being, but without any particular qualities or things to he, is the highest attainment of metaphysical skill. Belief. — Things which we receive and admit as true although not directly known to us are said to be believed, and the act of the mind in assenting to this truth is belief. Category. — The classes of things to one or other of which all known objects must belong Avere called, by Aristotle, categories ; into some one or more of these classes everything knowable could be placed. They were ten in number : sub- stance, quantity, quality, relation, action, passion, time, place, situation, and habit. Hence category comes to be nearly synonymous with class or list. And, as the categories indicate the assertions or predications which may be made regarding any object, a proposition affirming any of these assertions is called categorical. Hence, generally, categorical means direct or abso- lute as distinguished from indirect, conditional, or hypothetical. Causal. — Pertaining to a cause. Causation. — The act of causing or producing anything which begins to be. Cause. — The agent or power by the operation of which any change is produced or any action or condition effected. By some writers cause is held to mean the invariable antecedent of some event without which the event could not be. Class. — A group of individual objects of knowledge collected together in consequence of their resemblance in certain elements is called a class. Classification. — The act of arranging individuals into classes, or lower into higher classes. Cognise. — A term frequently used in psychology, meaning to know. Cognition. — The act of Icnoiuing, in the proper sense of the term, is called cognition. This term is used especially in contra- distinction to feeling and volition, two other and distinct classes of mental phenomena. The powers of the mind engaged in the different processes of cognition are called cognitive. Colour. — The name of that quality which is known through the sense of sight. There is an ambiguity in the application of the term colour; sometimes it is applied to the sensation in the 350 VOCABULARY OF PEILOSOPEICAL TERMS. mind which results froili our looking at objects through the eyes ; sometimes to the appearance of colour located upon the object ; sometimes to the unperceived cause or condition which gives rise to the sensation. The second of these applications appears the most natural and correct. Compare. — To observe the resemblance, difference, or other relation between two objects of knowledge. The act or process of comparison is an important means of acquiring knowledge. Conceive. — To bring before the mind the idea or image of some quality or object which has been previously directly known. Thus it is nearly synonymous with imagine. Concept. — Literally that which has been conceived or imagined. But the word is generally used in a restricted sense to indicate the conceived qualities of a class of objects by which all the members of the class are characterised and distinguished from other classes. Conceptualism. — The name of a doctrine according to which the concept of a class of objects is regarded as being general instead of the nameoi the class or the class itself. Concomitant. — When several objects of knowledge or thought appear before the mind at the same time they are said to be concomitant. Conscience. — The ability which we have to discern between the rightness and wrongness of actions. Consciousness. — The immediate knowledge which the mind has of its own acts or operations is called consciousness. Conscious-subject. — That which is conscious of the opera- tions and objects of the mind in immediate knowledge is called the conscious. subject, self or ego. Consequence. — The act or condition of following from some- thing that has gone before. Used chiefly in logic. ConseCLUent. — When two objects of knowledge appear in sequence, the one following the other, that which follows is the consequent. Contiguity. — A principle of association uniting two or more objects that have appeared before the mind, the bond of union being that they have been known near to one another either in time or place. Correlation. — When two objects or series of objects are mutually related to one another they are said to be in corre- lation, and they are called correlatives. Cosmology. — That branch of universal philosophy which treats of the formation and laws of the cosmos or universe. 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Gray.— STRUCTURAL BOTANY, OR ORGANOGRAPHY ON THE BASIS OF MORPHOLOGY. To which are added the principles of Taxonomy and Phytography, and a Glossary of Botanical Terms. By Asa Gray, LL.D , Tisher Professor ot Natural History (Botany) in Harvard University. With numerous Illustrations. Svo. los. 6d. Green. — a SHORT GEOGRAPHY OF TPIE BRITISH ISLANDS. By John Richard Green and Alice Stopford Green. With Maps. Fcap. Svo. 3^. 61. The Times says : — *' The method of the work, so far as real in- struction is concerned, is nearly all that could be desired, . . . Its great merit, in addition to its scientific arrangement and the attractive style so familiar to the readers of Green s ' Short History ' is thai the facts are so presented as to compel the careful student to think for himself. .... The work may be read tvith pleasure and profit by anyone ; we trust that it will gradually find its way into the higher forms of our schools. 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" This is, 7vithout doubt, one of the most interesting and valuablt books of travel published for many years."" — Spectator. Huxley and Martin.— a COURSE OF PRACTICAL IN- STRUCTION IN ELEMENTARY BIOLOGY. By T. H. Huxley, LL.D., P.R.S., assisted by H. N. Martin, M.A., F.R.S., M.B., D.Sc, Fellow qf Christ's College, Cambridge. Crown Svo. 6j. ** This is the most thoroughly valuable book to teachers and students of biology zvhich has ever appeared in the English tonguer — London Quarterly Review. Huxley (Professor). — Works by T. II. Huxley, LL.D., P.R.S. LAY SERMONS, ADDRESSES, AND REVIEWS. New and Cheaper Edition. Crown Svo. *]s. 6d. Fourteen Discourses on the following subjects: — (i) On the Advisable- ness of Improving Natural Knozvledge: — (2) Efftancipation — Black and White : — (3) A Liberal Education, and where to find //;_(4) Scientific Education :—{S) On the Ediuational Vcdue of the Natural History Sciences:— {6) On the Study of Zoology:— PHYSICAL SCIENCE. 15 Huxley i^roiQ-^^ov)— continued. (7) On the Physical Basis ofLife:—{%) The Scientific Aspects of Positivism :—{g) On a Piece of Chalk: — (10) Geological Contem- poraneity and Persistent Types of Life :— {11) Geological Reform : — (12) The Origin of Species :— [it,) Ciiticisms on the ''Origin of Species:"— [i^) On Descartes^ ''Discourse touching the Method of usiftg One's Reason rightly and of seeking Scientific T'uth." ESSAYS SELECTED FROM "LAY SERMONS, AD- , DRESSES, AND REVIEWS." Second Edition. Crown 8vo. is. CRITIQUES AND ADDRESSES. 8vo. los. 6d. Contents: — i. Administrative Nihilism. 2.. 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Taylor. — sound and music : A Treatise on the Physical - Constitution of Musical Sounds and Harmony, including the Chief Acoustical Discoveries of Professor Helmholtz. By Sedley Taylor, M.A., late Fellow of Trinity College, Cambridge. With Illustrations. New Edition. Extra crown 8va %s. 6d. " In no previous scientific treatise do zue remember so exhaustive and so richly illustrated a description of forms of vibration and of wave-motion in fluidsP— Musical Standard. Thompson (Silvanus P.). — ELECTRICITY AND MAG- . NETISM, ELEMENTARY LESSONS IN. By Silvanus P. Thompson, B.A., D.Sc, F.R.A. S., Professor of Experimental Physics in University College, Bristol. With Illustrations. New Edition. Fcap. 8vo. 4^. 6r/. 24 SCIENTIFIC CATALOGUE. Thomson.— Works by Sir Wyville Thomson, K.C.B., F.R.S. THE DEPTHS OF THE SEA : An Account of the General Results of the Dredging Cruises of H.M.SS. "Porcupine" and "Lightning" during the Summers of 1868-69 and 70, under the scientific direction of Dr. Carpenter, F.R.S., J. Gwyn Jeffreys, F.R.S., and Sir Wyville Thomson, F.R.S. With nearly 100 Illustrations and 8 coloured Maps and Plans. Second Edition. Royal 8 vo. cloth, gilt. 'i^is. 6d. The Athenaeum says : ** The book is full of interesting matter^ and is written by a master of the art oj popular exposition. It is excellently illustrated, both coloured maps and woodcuts possessing high merit." THE VOYAGE OF THE "CHALLENGER."— THE ATLAN- TIC. A Preliminary account of the Exploring Voyages of H.M.S. "Challenger," during the year 1873 and the early part of 1876. With numerous Illustrations, Coloured Maps & Charts, & Portrait of the Author, engraved !byC. H. J EEN.S. 2 Vols. Medium 8vo. 45^-. The Times says : *^ The paper, printings and especially the numerous illustrations, are of the highest quality. . . . We have rarely, if ever, seen more beautiful specimens of wood engraving than abound in this work. . . . Sir Wyville Thomson^ s style is particularly attractive ; he is easy and gracejul, but vigorous and exceedingly happy in the choice of language, and throughout the work there are touches which show that science has not banished sentiment f-om his bosom.'* Thudichum and Dupre. — a TREATISE ON THE ORIGIN, NATURE, AND VARIETIES OF WINE. Being a Complete Manual of Viticulture and CEnology. By J. L. W. Thudichum, M.D,, and August Dupre, Ph.D., Lecturer on Chemistry at Westminster Hospital. Medium 8vo. cloth gilt. 25J. ** A treatise almost unique for its usefulness either to the wine-grower, the vendor, or the consumer oftuine. The analyses of wine are the most complete we have yet seen, exhibiting at a glance the constituent principles of nearly all the wines known in this country.*' — Wine Trade Review. Ty lor.— ANTHROPOLOGY : an Introduction to the Study of Man and Civilization. By E. 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A few judicious notes are added 26 SCIENTIFIC CA TALOGUE, Wurtz — continued. by the translator."— Tall Mall Gazette. " T/ze treatment of the subject is admirable, and the translator has evidently done his duty most efficiently.'''' — Westminster Review. Ziegler— Macalister — text-book OF PATHOLOGICAL ANATOMY AND PATHOGENESIS. By Professor Ernst Ziegler, of Tubingen. Translated and Edited for English Students by Donald Macalister, M.A., M.B., B.Sc, Fellow of St. John's College, Cambridge. With numerous Illustrations. Medium 8vo. Part I.— GENERAL PATHOLOGICAL ANA- TOMY. \2s. 6d. [Part II. in the press. SCIENCE PRIMERS FOR ELEMENTARY SCHOOLS. Under the joint Editorship of Professors Huxley, Roscoe, and Balfour Stewart. Introductory. By Professor Huxley, P. R.S. i8mo. is. Chemistry By H. E. Roscoe, F.R.S., Professor of Chemistry in the Victoria University, the Owens College, Manchester. With numerous Illustrations. i8mo. i^*. New Edition. With Questions. 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A Complete Treatise on Inorganic Chemistry. By Pro- fessor H. E. Roscoe, F.R.S., and Professor C. Schorlemmer, F.R.S. With numerous Illustrations. Medium Svo. Vol. I. — The Non-Metallic Elements. 21J. Vol. II.— Metals.— Part I. \%s. Vol. I L— Metals. Part IL iSj. organic CHEMISTRY. A complete Treatise on Organic Chemistry. By Professors RoscoE and Schorlemmer. With Humerous Illustrations. Medium Svo. Part I. 21J. Part II. 21S. Schorlemmer.— A MANUAL OF THE CHEMISTRY OF THE CARBON COMPOUNDS, OR ORGANIC CHEMISTRY. By C. Schorlemmer, F.R.S., Professor of Chemistry, the Victoria University, the Owens College, Manchester. "With Illustrations. Svo. 14J'. Sidgwick.— THE PRINCIPLES OF POLITICAL ECONOMY. By Henry Sidgwick, M.A., Professor in Moral Philosophy in the University of Cambridge, Author of "The Methods of Ethics." Svo. 1,6^. Smith. — A DICTIONARY OF ECONOMIC PLANTS. Their History, Products, and Uses. By John Smith. Svo. 14J. 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Being the Morse Lecturer, 1880, connected with Union Theological Seminary, New York. Crown 8vo. 55. Clifford.— LECTURES AND ESSAYS. By the late Professor W. K. Clifford, F.R.S. Edited by Leslie Stephen and Frederick Pollock, with Introduction by F. Pollock. Two Portraits. 2 vols. 8vo. 25^. [See also page 2. ** The Times of October 2.2nd says : — "Many a friend of the author OH first taking up these volumes and remembering his versatile genius and his keen enjoyment of all realms of intellectual activity must have trembled, lest they should be found to consist of fragmen- tary pieces of work, too disconnected to do justice to his powers of consecutive reading, and too varied to have any effect as a whole. Fortunately these fears are groundless. . . . It is not only in subject that the various papers are closely related. There is also a sintrular consistency of view and of method throughout. , . . It . is in the social and metaphysical subjects that the richness of his intellect shows itself, most forcibly in the rarity and originality of ihe ideas which he presents to us. To appreciate tJiis variety it is necessary to read the book itself, for it treats in some form or other of all the subjects of deepest interest in this ape of questioning.** MENTAL AND MORAL PHILOSOPHY, ETC. 37 ^iske. — OUTLINES OF COSMIC PHILOSOPHY, BASED ON THE DOCTRINE OF EVOLUTION, WITH CRITI- CISMS ON THE POSITIVE PHILOSOPHY. By John FiSKE, M.A., LL.B., formerly Lecturer on Philosophy at Harvard University. 2 vols. 8vo. 25^. ** The work constitutes a very effective encyclopcedia of the evolution- ary philosophy, and is well worth the study of all who wish to see at once the entire scope and purport of the scientific dogmatism of the day." — Saturday Review. Fowle. — A NEW ANALOGY BETWEEN REVEALED RELIGION AND THE COURSE AND CONSTITUTION OF NATURE. By Rev. T. W. 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S£ !K mmn SESSIONS EDUaTiON-PSYCHOLO^Y tfSftftfiY NOV 3 1969 NOV 10 196^ NOV 3REn'n-2P' MAR 11 1974 0CT2 8RECD FEB 2 3 REC'D -U AM JAN 2 1974 2 6 1963 DECl^HECD DEC27REC'D-l?|VI NOV ^^1364 NOI/li R£CU MAY 10 1965 LD 21-50m-6,'60 (B1321sl0)476 General Library University of California Berkeley