1 A ■^ -^ate stamped below. THE SENSES AND THE INTELLECT BY ALEXANDER BAIN, LL.D. EMERITUS PROFESSOR OF LOGIC IN THE UNIVERSITY OF ABERDEEN FOURTH EDITION NEW YORK D. A PPL ETON AND COMPANY 1902 ^cb. ieo2, 3 c PltEFACE. ri'lHE ol)ject of this treatise is to give a full ai -^ systematic account of two principal divisions and systematic account of two principal divisions of the science of Mind — the Senses and the Intellect. The repiaining two divisions, comprising the Emotions and the Will, will be the subject of a future treatise. While endeavouring to present in a methodical form all the important facts and doctrines bearing upon mind, considered as a branch of science, I have seen reason to adopt some new views, and to depart, in a few instances, from the most usual arrangement of the topics. Conceiving that the time has now come Avhen many of the striking discoveries of Physiologists relative to the nervous system should find a recog- nized place in the Science of Mind, I have devoted a separate chapter to the Physiology of the Brain and Nerves. In treating of the Senses, besides recognizing the so-called muscular sense as distinct from the five senses, I have thought proper to assign to Movement and the feelings of Movement a position preceding the Sensations of the senses ; and have endeavoured to prove that the exercise of active energy, origi- nating in purely internal impulses, independent of the stinuilus produced by outward impressions, is a primary fi\ct of our constitution. Among the Senses have been here enrolled and IV • PEEFACE. described with some degree of minuteness, the feehngs connected with the various processes of organic Kfe, — Digestion, Respiration, etc. — which make up so large a part of individual happiness and misery. A systematic plan has been introduced into the description of the conscious states in general, so as to enable them to be compared and classified with more precision than heretofore. However imperfect may be the first attemi)t to construct a Natural History of the Feelings, upon the basis of a uniform descriptive method, the subject of Mind cannot attain a high scientific character until some progress has been made towards the accomplishment of this object. In the department of the Senses, the Instincts, or primitive endowments of our mental constitution, are fully considered ; and in endeavouring to arrive at the original foundation, or first rudiments, of Volition, a theory of this portion of the mind has been sug- gested. In treating of the Intellect, the subdivision into feculties is abandoned. The exposition proceeds entirely on the Laws of Association, which are ex- emplified with minute detail, and followed out into a variety of applications. London, June, 1855. PREFACE TO THE SECOND EDITION. ^pms edition has lieen thoroughly revised, and in -^ many places re-written. Although I have not seen reason to change any of my leading views on the subject of Mind, I hope I may have succeeded in improving the statement and exposition of them. It is in the first part of the work where most alteration has been made. The explanations of the Nervous svstem and the Senses have been amended according to the best recent authorities on Physi- ology. The Definition of Mind has been somewhat differently exjDressed. The systematic plan of de- scribing the Feelings has been modified, and all the detailed descriptions re-cast. An attempt has been made to generalize the Physical accompaniments of Pleasure and Pain. The Instinctive foundations of Volition are stated more explicitly. In the second part, the Introduction to the Intel- lect has been revised, with a view to rendering as precise as possible the natural subdivisions of this portion of the mind. The doctrine referring to the physical seat of revived impressions has been dis- cussed anew, and applied to clear u^j the difficulties attending the explanation of Sympathy. The associ- ating principle of Contrast has, on further considera- tion, been treated as the reproductive aspect of Discrimination, or Relativity. The origin of our notions of Space and Time has been more minutely traced ; and some additions have been made to the handling of the great Meta- physical problem, relating to the External World. Aberdeen, February, 1864. ll PREFACE TO THE THIRD EDITION. TN this third edition, the work has again been suli- ^ jected to a thorough revision, involving numerous amendments both in matter and in style. The sketch of the ]Servous System, and the Physiological references generally, have been com- 23ared with the statements given in the newest works. The Reflex Actions, illustrating the Will, by contrast and by resemblance, are more fully and systematically discussed. In the Intellect, the fundamental conditions, both of Retentiveness and of Similarity, have been set forth with greater precision ; whereby clearness is gained in following out the details of those great leading functions. The value of the work is greatly enhanced by an account of the Psychology of Ai^stotle, which has been contributed bv Mr. Grote. The chief signi- ficance of Aristotle's views, at the present day, lies in his recognizing, in an almost unqualified manner, the doul)le-sidedness of the mental states. Aberdeen, September, 1868. PREFACE TO THbl FOURTH EDITION. A FTER a considerable interval of time, in the ^ course of which psychological investigation and discussion, both in Europe and in America, have been more actively carried on than during any former period of philosojjhical history, I now, for the last time, re-issue this work, with such additions, modifi- cations and emendations as have commended them- selves to my mind. I have endeavoured to take full advantage of the numerous suggestions in contem- porary philosophical literature, and, while adhering to the main points of doctrine, and the general plan of arrangement, I have introduced improved forms of statement, and corrected what I deemed either in- accurate or imperfect in the expression. In regard to the physiological portions, the chapter on the Nervous System has been entirely re-written. This task has been executed by Dr. W. Leslie Mackenzie, Medical Officer of Health for the counties of Kirkcudbright and Wigton, who has spared no pains to embody the results of the latest authorities. I have profited by his assistance, also, in im})roving the physiology of the Senses. My conviction of the propriety of bringing these topics before the student, notwithstanding the adverse opinion of many, has been strengthened rather than otherwise. It is not merely that the definitions and the doctrines of physiology have a direct ap})lica- tion, and that their absence would make psychology poorei' in its own province, — it is, further, that the expression of mental states is, in many ways, aided Vlll PEEFACE. by reference to their physical adjuncts. Even when such adjuncts are so imperfectly known as to have only a hypothetical rendering, the mention of them is still valuable in improving our scanty resources of subjective delineation. Perhaps it may be said that the student should refer to works of Anatomy and Physiology for this special instruction, — which is quite true. At the same time, the including of a suitable physiological selection in a treatise of psychology proper has high expository value. It is now generally recognized that systematic Psychology should be disburdened of Metaphysics — that is, the problem of knowing and being, — however closely they may be connected. To analyze Subject and Object is a strictly psychological task : the nature of our Perception of a material world is something different and apart. Likewise, what is now termed Epistemology has psychological relation- ships, but is pursued into issues of a specific char- acter, lying outside pm^e psychology. The chapter on Instinct, which contains the fun- damentals of Pleasure and Pain, together with their physical embodiment and expression, and the germ of Volition, has been so far re-cast as to make more explicit the distinction between the Physical and the Mental, while assigning due force to each. The supposed origination of our mental products, known to us only in their maturity, has entered largely into psychological inquiiy. Whether certain fundamental conceptions— such as Space, Time, Cause, the Moral Sense, the Ego or Personality, — are instinctive, or grow out of experience and edu- PREFACE. IX cation, has long been the battle-ground of the lihilosophy of mind. The controversy may have a somewhat factitious importance ; at all events, it is regarded with more than merely speculative curiosit} . The argumentative treatment, however, has assumed a new aspect from the doctrine of evolution, taken in the guarded form of the hereditary transmission of foregone aptitudes or acquirements. Instead of Kant's contention that the notion of Space, as a ' form of thought,' is prior to any experience on the part of each individual, the (juestion now is, whether or not we possess at birth a large contribution to- wards the full realizing of the three dimensions of the extended world. Such a mode of looking at the problem changes the whole character of the research into origins ; depriving us of the right to define the absolute commencement of any of the great fundamental notions, and leaving us merely to watch their accessions of growth within the s^jhere of our observation, and to reason by analogy as to their probable course or manner of growth before entering that sphere. It may, however, be still argued, without fear of rejoinder, that experience or acquisition is the remote genesis of what transcends our available sources of knowledge. The (jualifica- tions introduced in the present edition of this work, having reference to experience as opposed to instinct, have taken shape in accordance with the leading- hypothesis above sketched. The plan and object of the present work, as well as of its continuation The Emotions (uid Ihc Will, having been conceived more exclusively with a view X. PREFACE. to practical results, I have seen no ground for ma- terially altering the expository order and the propor- tions, in the laving- out of the details. The Retentive power of the ]\Iind, which occuj^ies the largest division of the Intellectual Powders, has received some additions, with a view to elucidate still further the more complex bearings of the Re- cuperative process. I recognize, in the broadest sense, the possibility of advancing psychological doctrines by means of well-contrived experiments. The researches usually called psycho-ijhysical have already borne some fruits, and hold out still greater expectations for the future. They can, at best, cover but a small portion of the wide domain of psychological research ; but, if pursued with a clear recognition of introspective concurrence, they may accelerate the pace of psycho- logical investigation, more especially on the side of practical usefulness. The account of the Psychology of Aristotle, con- tributed by Grote to the previous edition, having been embodied in his own })ostliumous work on Aristotle, is here omitted. Subsequently to the pul)lication of the former edition, I appended a Postscript, containing a minute and exhaustive criticism of the psychological parts of Darwin on Expression. This has l^een retained in the present edition. It serves the purpose of ex- panding the treatment in the text, and also of illus- trating at length the alternative positions as to the respective priority of Emotion and Volition in the order of development. Aberdeen, Aj>r//, 189-i. TABLE OF CONTENTS. INTRODUCTION. CHAPTER I. DEFINITION AND DIVISIONS OF MIND. PAGE 1. Mind opposed to the Extended ... ... ... .. ... 1 e 2. Mind lias three properties, — Feeling, Volition, Thought 2 3. Elucidation of these properties ... ... ... ... ... ib. 4. Classifications of Mind. — Understanding and Will ; Intellectual Powers and Active Powers ; Brown's di^^sion ; Hamilton's. Maimer of expressing the mutual solidarity of the fundamental attributes of Mind. Priority of the powers in the order of de- pendence. Fundamental truths of Psychology ... ... 6 5. Plan of the present volume ... ... ... ... ... .. 8 CHAPTER' II THE NERVOUS SYSTEM. 1. Connexion of mental processes with bodily organs .. ... 9 2. Proofs that the Brain is the principal organ of Mind ... ... ih. Connexion of size of Brain with mental energy ... ... ... ih. STRUCTURE OF THE NERVOUS SYSTEM. General View of the Nervous System. Nervous System divided into two parts, —a Central part and an Internuncial part ... ... ... ... ... ... ... H The Central part the Ccrc6ro- ^roTmnn i-i nr prpnpra.1 j^Piisi bJIity 102 , Propriety of constituting the feelings of Organic Life into a class of sensations ... ... ... ... ... ... ... 103 Emotional and Intellectual Senses ... ... ... ... ... lb. Preliminary Bi marks vpon Sensation in general. (1) Sensations of every-day life no longer typify their original character. Distinction between them and the thought- processes ... ... ... ... ... ... ... ... 104 ♦ (2) Sensation conditioned by the law of iic7«^m"TiGuous Aggregates : — Conjunctions. 23. Popular classification of Natural objects. Ke-classifying of things already classified ... ... ... ... ... 518 24. Things affecting a Plurality of Senses 520 25. Compounds of Sense and AssociatioQ : — Objects identified from their Hscs .- mechanical invention ; the steam-engine ... ib. 26. Natural objects identified on their scientific properties. Chemical discoveries ... ... ... ... ... ... ... ... 523 27. Classifications of the naturalist ; Linnteus. Analogies struck by Goethe and Oke?i ... ... ... ... ... ... ... 526 28. The Animal Kingdom : — Improved classifications ; homologies of the skeleton ; mental peculiarities of Oken ; enlargement of our knowledge through the discovery of real identities ... 527 Phenomena of Succession. 29. Various modes of Succession. Of identities, some are real, others illustrative 529 30. Identification among the different classes of successions : — Cycles ; Evolutions 530 31. Successions of Human History ; historical comparisons ... ... 532 32. Institutional comparisons — the science of Society ... ... ... 535 33. Scientific causation : Newton's discovery of universal gravita- tion ; intellectual character of Newton .. . ... ... ... 536 Eeasoning and Science in Geneeal. 34. The different processes of Science: — Abstraction ; Controversy of Nominalism and Realism ... ... ... ... ... 541 35. Induction : the inductive process demands the powor of Simi- larity ; Inductions fitted into previously established for- mulas ; Laws of Kepler ... ... ...^'•^.l ... ... 544 36. Deduction: — transfer or extension of prope to new cases; Newton on the diamond ; given an ob acur case to find a principle to illuminate it ; Franklin's ' "identication of light- ning and electricity / 548 37. Reasoning by Analogy ... ... ■■■ S ■■■ .■ ••• ••■ ^^2 38. The explanation of the Reasoning Facujlty ... 553 Business and Praactice. 39. Inventions in the arts : — James Watt ; jAdministratiou of public XXVlll CONTENTS. and private business; already in use 40. Persuasion Extension to new cases of [devices Illustrative Comparisons and Literary Art. 41. Comparison an aid to intellectual comprehension: — Bacon 42. Comparisons for ornament and effect : — the Orator and the Poet 43. Figures of speech implying comparison The Fine Arts in General. 44. Some of the Fine Arts involve the intellect largely 45. The less intellectual Arts ; Intellect in the Fine Arts generally Similarity in Acquisition and Memory. 46. Similarity, by tracing repetitions, shortens the labour of acquir ing new subjects ... 47. Examples from Science 48. Business acquisitions ... 49. Case of the Artistic mind 50. Contiguity tested only by entire and absolute novelty 51. The Historical Memory Concluding Observations. 52. Faculties implicated in the operation of Similarity : — Beasoning Imagination 53. Is there a power of General Similaritj' ? 54. Question: — Can Similarity as such be improved ? PAGE 554 558 559 562 563 564 565 567 Ol^ ,.(}. 573 574 ih. CHAPTER III. COMPOUND ASSOCIATION. 1. There may exist in any one case a plurality of associations. Statement of the law Composition of Contiguities. 2. Contiguous conjunctions : — complex wholes and concrete objects. An additional link may often be itself sufficient to effect the recall 3. Connexion with locality and with persons. Searching for things lost 4. Connexion of t' '■ gs with uses 5. Successions: — tf/' .* Vietssion of Order in Time 6. Language ... .... . ' Composition of Similarities. 7. Increase of p' . ity in bringing on a difficult identification 577 578 580 582 583 584 585 587 ib. 588 CONTENTS. XXIX PAGE The Element op Feeling. {" 11. An emotional state gives its characters to the trains of recollection 589 \ 12. The purely intellectual bonds are made subordinate in emotional natures ... ... ... ... .• ... ... ■■• 590 Influence of Volition. » 13. Modes whereby volition may operate in resuscitating the past 591 (1) By the stimulus of excitement 592 (2) By controlling the intellectual attention ib. A Complex Start Needed for a Single Train. li. Concurrence of other suggesting circumstances with an object before the view ... ... ... ... ... ... ... 594 15. Selection of one out of many properties of the same object ... 596 \ , Obstructive Association. • " ■"'^collection obstructed by the mind's being possessed with something different 597 ±1. Conflict of the Artistic and the Scientific modes of viewing the world. Guessing of conundrums 598 Association of Contrast. • 18. Contrast is the reproductive phase of Discrimination or the Law of Relativity 599 19. Contiguity and Pimilarity concur in recalling contrasts 600 20. Contrasts are often accompanied with Emotion 602 21. The power of Similarity, under the guise of contrast, clears the mind of contradictions ... ... ... ... ... 603 CHAPTEE IV. CONSTRUCTIVE ASSOCIATION. • 1. There is in the mind a power of original construction 605 ]\Iechanical Constructiveness. • 2. Complex acts acquired by taking the simple acts separately. The three conditions of constructiveness generally ... ... 606 Verbal Constructiveness. 3. Constructiveness in Speech. Illustration of Volition as an element in constructiveness ... ... ... ... ... 607 4. Fulfilment of the conditions of grammar, etc. ilT'\cessity of a large stock of vocables. The similes of pc* -3 ' ... ... 610 Feelings op Movemen' 5. Construction of non-experienced ideas of Wel^ Range, etc. The Associations of Architecture ... '^ . - ... ... 612 Constructiveness in the Sensati • 6. Forming by combination new states of Organic Feeling 613 7. Tactual constructions. Disassociation ... ..i',-, , ... ... 615 8. States of Hearing the result of a combining efiox*^<. J 'iv G16 9. Constructiveness in Sight J-x^t 617 XXX CONTENTS, PAGE Construction of New Emotions. 10. Elementary emotions of human nature must be experienced. Changing the degree of a known feeling ... ... ... 619 11. Combining of two emotions so as to bring out a third. Examples 621 CONCEETING THE ABSTRACT. 12. Given the abstract properties of an object, to conceive the object itself 622 13. The farther abstraction is carried, the more difficult it is to remount to the concrete ... ... ... ... ... ... 624 Realizing of Representation or Description. 14. The methods of representation ... ... ... ... ... ib. 15. Verbal description ... ... ... ... ... ... ... 625 16. Maxim of the describing art in general ; — to combine a type with an enumeration ... ... ... ... ... ... ib. Constructiveness in Science. 17. Constructiveness in Abstract ideas ... ... ... ... ... 627 18. Induction 629 19. Processes of Deduction ; creations of mathematics ... ... 630 20. Experimental science ... ... ... ... ... ... ... ib. Practical Constructions. 21. Region of practical inventions. The turn for experimenting, an attribute of inventors : Kepler, Herschel, Daguerre ... ... 631 22. The mental quality termed soundness of Judginent. The power of adaptation to complicated conditions ... ... ... 633 Fine Art Constructions — Imagination. 23. The presence of an emotional element in intellectual combina- tions. Distinction between the constructions of Imagina- tion and the constructions of science and of practice. Note 635 24. Combinations ruled by emotions : — Terror, Auger .. . ... ... 637 25. Superstructures reared on Egotistic feeling 640 26. Constructions to satisfy the emotions of Fine Art properly so called 642 27. The artist's standard is the feeling of the effect produced ... 643 28. Reconciliation of Art with Nature ; the regard due to truth by an artist ... ... ... ... ... ... ... ... 645 APPENDIX. A. Definition and Divisions of Mind. I. Mutual solidarity of the three Powers : — Question whether the three fundamental properties of Mind can operate in separa- tion, or whether they are necessarily co-present ... ... 647 II. Order of Dependence or Causation of the Three Powers : — The threefold division of Mind first explicitly made in Germany. Hamilton holds that Cognition is the foundation property, with a qualification. Herbart made Intellect the exclusive CONTENTS. XXXI PACE fouu elation. The same doctrine repeated by Volkmann. Dr. Ward's statement of fundamentals with their mutual dependence ... ... ... ... ... ... ... ... 648 B. Pleasure and Pain. ' Connexion of Pleasure with Remission or Change — not the same as the Law of Vitality. Signal failure of the law of vitality or Conservation when put to the test of measured concomitance. Additional failure to explain the pleasures of Harmony. Stimulation is the groundwork of the principle of Credit ; no provision for exact repayment ... ... ... ... 654 Review of Darwin on ' Expression ' . -- - Darwin's three principles. The first, entitled ' The principle of Serviceable Associated Habits'. Second, 'Antithesis'. Third, ' The principle of actions due to the constitution of the Nervous System '. Criticism of those principles. Im- , portance of Spontaneity of Movements. Illustrations fur- nished by Darwin himself. The Law of Diffusion : Ex- amples from Darwin. ^Meaning of the principle of Anti- thesis. His treatment of the law of Pleasure and Pain as related to heightened and lowered vitality. Critical examina- tion of his examples. Law of consentaneous action of the muscles. Limitation and Diversion of Energy. Inheritance of Emotional Expression — Anger and Fear. Frowning : — Key to the expression of the features in pain. Theory of Blushing 657 C. Seat of Bevived Impressions. x" Illustration by Wundt. Opinion of Kant. Sir W. Hamilton's state- ment of the view. Spencer's theory of Memory ... ... 672 Deeper physical accompaniments of thought : — Inferiority of the Idea to the Sensation, physically as well as mentally. The Idea as favoured by Recency. Physical conditions notably affect the recovery of the Recent ... ... ... ... ... 674 D. Tlie Presentation Continuum. ' The doctrine of Association opposed by the view of differentiation of a primitive homogeneous continuity. The hypothesis of Evolution supplies the best situation for the play of this principle. The beginning of the Infant life can only for a moment exemplify a homogeneous consciousness ; differentia- tion must already have done its work. Growing delicacy of sense discrimination ; the amount of improvement a limited quantity 676 \ Contiguous Association in the Ideas of Natural Objects : — .\ssertion of Dissociation, rather than Association ; as the means of training the intellect. Proper sphere of Dissociation . . . 679 XXXll CONTENTS. PAGE E. Subjective Studies and Regards. Contrast of the Object and Subject directions of the mind. Study of the sciences of the External or Object world. Knowledge of the mind not wholly Subjective. Pleasure and Pain, pure Subjectivity. Ethical Self-examination. Objective regards — their advantages and disadvantages. Excessive Subject- ivity. The studj' of the mind must contain an element of Introspection ... ... ... ... ... ... ... 680 F. The Abstractions — Number, Space, Time, Self. * Question as to the intuitive source of our knowledge. Innate elements stated either as Notions, or as Principles. Enumeration of innate elements ... ... ... ... ... ... ... 684 Nuinher. — Quantity the most comprehensive attribute of things. Con- tinuous Quantity. Discrete quantity, or Ninnber. The most perfect expression of quantity. Not an intuition ... ... 685 Space. — Our notion of Space or Extension possesses a certain degree of advancement at birth. Supposed hereditary transmission. Not incompatible with the doctrine that assigns its genesis to experience. ' Forms of Thought ' not an adequate ex- pression of the notion as possessed at birth ... ... ..'. 686 Time. — An intuitive ' form ' of the a priori school. Must be grounded on our feeling of the continuous in our various sensibilities. Discrimination of degree in Duration. Consciousness of succession, as uniting past and present reality. Repre- sentative machinery for enlarging our expression of time. Question whether we have an instinctive preparation for our conception of time. Feeling of flight of time as rapid or slow ... ... ... ... ... ... ... ... 688 Self — The 3/0 — Personality. — Inheritance from the past may enter into our notion of Self. Allied issues to the distinction of Self and Not-self. Problem of genesis : — what are the ultimate elements entering into the development of our consciousness of Self, and what is the order of time in their respective contributions ? The child takes cognizance of its own body. The Organic Sensations an initial element. Self as active. Ideation as opposed to Sensation. Relations to other personalities — Language. Lateness and difficulty of separating the inner self from the bodily self. Personal Identity. The composite notion of Personality ... ... 691 G. Classifications of the Intellectual Poiuers. Reid. Dugald Stewart. Hamilton. Samuel Bailey. Herbert Spencer. Professor Sully. Professor Hoffding. Dr. James Ward 695 SujJj^lementary Note on the Expression of the Laws of Association. Critical examination by Dr. Ward 707 INTRODUCTION. CHAPTEE I. DEFINITION AND DIVISIONS OF MIND. 1. rPHE operations and appearances that constitute Mind JL are indicated by such terms as Feehng, Thought, Memory, Reason, Conscience, Imagination, Will, Passions, Affections, Taste. But the Definition of Mind aspires to comprehend in few words, by some apt generalisation, the whole kindred of mental facts, and to exclude everything foreign to these. Mind is commonly opposed to Matter, but more correctly to the so-called External World. These two opposites define each other. To know one is to know both. The External, or, in more philosophical language, the Object World is distinguished by the property called Extension, pertaining both to resisting Matter, and to unresisting, or empty Space. The Internal, or the Subject, World is our experience of everything not extended ; it is neither Matter nor Space. A tree, which possesses extension, is a part of the object world ; a pleasure, a volition, a thought, are facts of the subject world, or of mind proper. Thus Mind is definable, in the first instance, by the method of contrast, or as a remainder arising from subtract- ing the Object World from the totality of conscious experi- ence. It happens that the Object World is easily defined or circumscribed ; the one well-understood property, Extension, serves for this purpose. Hence the alternative, or the correlative Mind, can be circumscribed with equal exactness. 1 '■I DEFINITION AND DIVISIONS OF MIND. But this negative definition, although precise, so far as it goes, fails to indicate the full scope of the inquiry. The distinction of the Object and the Subject, the world of extension, and the world where extension has no part, is still farther shown by the manner of knowing the two. For the extended or outer world, we employ sense observation ; for the mental world, we use the power that we possess named self-consciousness or introspection. „ Farther, in observation, by the senses, we can work in the company of our fellow-beings ; the same world that is open to one is open to all, and the impression made is sub- stantially the same for all. In the exercise of introspection, each of us works apart and alone ; hence the study of the Subject is purely individual ; and this fact of Individuality is sometimes added to its definition. The importance of the distinction is seen in connnuni- cating knowledge from one to another. It is easier to impart Object knowledge, from the circumstance of identical discernment. In Subject knowledge, the communication is indirect, circuitous, while the attainment of a common understanding is precariouiiS. It has been found possible to sum up all the properly mental phases in a small immber of general properties, whose enumeration (which is strictly speaking a Division) is what we offer as a positive Definition of Mind. 2. The phenomena of the Unextended, or Subject Mind, are comprehended under three heads : — I. Feeling, which includes, but is not exhausted by, our pleasures and pains. Emotion, passion, affection, senti- ment, are names of Feeling. II. Volition, or the AVill, embracing the whole of our aictivity as directed by our feelings. III. Thought, Intellect or Cognition. Our Sensations, as will be afterwards seen, come partly under Feeling and partly under Thought. 3. First. For a notion of what Feeling is, we must refer each person to their own experience. The warmth felt FEELING. 6 ill sunshine, the sweetness of honey, the fragrance of flowers, the beauty of a landscape, are so many known states of feeling. Our pleasures and pains are all included under this head ; but many other states, both simple and complex, that are neutral as regards pleasure and pain, must also be referred to it. The entire compass of our Feehngs could be known only by an exhaustive enumeration ; from which also we might expect to obtain a general definition of Feehng. It is net requisite at this stage that we should either classify the feelings, or arrive at their common or defining properties. It so happens that we can readily circumscribe this part of our mental being by the negative method already exemplified in the definition of mind as a whole : for the characters both of thought and of volition are remarkably intelhgible and precise, and therefore give us a ready means of laying down the boundary of the remaining department. We may, however, remark, before passing to the consideration of the other divisions, that the presence of Feeling is the foremost and most unmistakable mark of mind. The members of the human race agree in manifesting it. The different orders of the l)rute creation show symptoms of the same endowment. The vegetable and mineral worlds are devoid of it. True, it is each in ourselves that we have the direct evidence of the state ; no one person's consciousness being open to another person. But finding all the outward appearances that accompany feeling in ourselves to be present in other liuman beings, and, under some variety of degree, in the lower animals, we naturally conclude their mental state to be similar to our owm. The gambols of a child, the smile of joy, a cry on account of pain, and the corresponding expressions for mental states common to all languages, prove that men in every age and nation have been similarly affected. The terms for expressing pleasure and pain in their various forms and degrees, are names of feelings ; joy, happiness, bliss, comfort, sorrow, misery, agony — are a few examples out of this part of the voca- bulary. Secondly. All beings recognised as possessing mind can 4 DEFINITION AND DIVISIONS OF MIND. not only feel, but also act. The exerting of force to attain some end marks a mental nature. Eating, running, flying, sowing, building, speaking — are operations rising above the play of feeling. They all originate in some feelings to be satisfied, which gives them the character of proper mental actions. When an animal tears, masticates and swallows its food, hunts its prey, or flees from danger, the stimulus or support of the activity is furnished by its sensations or feel- ings. To this feeling-prompted activity we give the name Volition. The characteristic of being stimulated by the feelings of sentient beings makes a wide contrast between volition and the energies familiar to us in nature, — the powers of wind, water, gravity, steam, gunpowder, electricity, vegetation, etc. For although the strong personifying tendency of mankind has often compared these powers to a human will, yet in reasoning about them scientifically no such comparison is admitted ; while, in the explanation of voluntary actions, the reference to feeling and to thought is indispensable. Volition is farther contrasted with such animal functions as breathing, the circulation of the blood and the movements of the intestines. These are actions, and serve a purpose, but they are not strictly mental actions. We could imagine ourselves so con- stituted, that these processes would have had to be prompted and controlled by sensations, emotions and desires ; they would then have been mental actions. k% it is, they form a class apart, denominated Eeflex Actions. When narrowly examined, they appear to shade by insensible degrees into voluntary actions ; but we are not on that account to confound the broad and fundamen- tal distinction between the unconscious and the conscious, involved in the opposition of the reflex and the voluntary. It is impossible, in a brief preliminary sketch, to indicate and discriminate all the varieties of animal activity. There is a complication to be unravelled in this department of the mind, such as to test severely the resources of mental science. It is sufficient to remark, as the most general law of volition, that pleasure prompts to action for its continuance, increase THOUGHT. 5 or renewal ; and that pain prompts to action for its cessation, abatement or prevention. Thirdly. The concluding attribute of the mental consti- tution is Thought, Intelligence, Intellection or Cognition. This includes such functions as Memory, Keason, Judgment and Imagination. The first fact implied in it is Discrimina- tion, or sense of difference, shown by our being conscious of one sensation as more intense than another, or when we are aware of two feelings as differing in kind, — for example, pain and pleasure, taste and smell, fear and anger. Another fact is Similarity, or sense of agreement, which is interwoven with the preceding in all the processes of thought. When we identify any sensation or present mental unpression with one that occurred previously, there being an interval be- tween, we exemplify the power of similarity ; the sun seen to-day recalls our previous impressions of his appearance. A third fact or property of the Intellect is Betentiveness, com- monly understood by the familiar names ' memory ' and ' recollection '. This power is essential to the operation of the two former powers ; we could not discriminate two suc- cessive impressions, if the first did not persist mentally to be contrasted with the second ; and we could not identify a present feeling with one that had left no trace in our frame- work. Betentiveness, which sums up all that we designate by memory, acquisition, education, habit, learning by ex- perience, is not wanting in the lower orders of sentient life. For an animal to have a home, a certain degree of memory is requisite. We have seen that Volition is separated from Feeling, by superadding the characteristic of actio)i, or the putting forth of energy to serve an end. And now, after the foregoing enumeration of Intellectual attributes, we can draw the line between Thought and Feeling, which is to complete the definition of mind, so far as is needful at the outset. In proportion as a mental experience contains the facts named discrimination, comparison and retentiveness, it is an Intellectual experience ; and in proportion as it is wanting in these, and shows 6 DEFINITION AND DIVISIONS OF MIND. itself in pleasure or pain, it is of the nature of Feeling. The very same state of mind may have both an intellectual side and an emotional side ; indeed, this is the usual occurrence. And, like many things that are radically contrasted, as day and night, these two distinct facts of our nature pass into one another by a gradual transition, so that an absolute line of separation is not always possible ; a circumstance that does not invalidate the genuineness of their mutual contrast. The exercise of Thought is greatly mixed up with Voli- tion also, but there is rarely any difficulty in distinguishing the two functions. Indeed, it is a matter of doubt whether we can ever exist in one state alone. Still, in our explana- tions of things, we often require to separate in statement what is not separated in fact. 4. If we advert to the various classifications of the mental phenomena that have hitherto passed current, we shall find that the three attributes above specified have been more or less distinctly recognised. In the old division of mind into Understanding and Will, the element of Feeling would appear to be left out entirely. We shall find in fact, however, that the feelings are implicated in, or placed under, both heads. The same remark applies to Reid's classifica- tion, also twofold and substantially identical with the foregoing, namely, into Intellectual Potoers and Active Poivers. The sub- merged department of Feeling will be found partly mixed up with the Intellectual Powers, wherein are included the Senses and the Emotions of Taste, and partly treated of among the Active Powers, which comprise the exposition of the benevolent and the malevolent Affections. Dr. Thomas Brown, displeased with the mode of applying the term ' Active ' in the above division, went into the other extreme, and brought forward a classification where Feeling seems entirely to overlie the region of Volition. He divides mental states into External affections and Internal aff'ections. By external affections he means the feelings we have by the Senses, in other words. Sensation. The internal affections he subdivides into Intellectual states of mind and Emotions. His division therefore is tanta- mount to Sensation, Emotion, and Intellect. All the phenomena FUNDAMENTALS OF MIND. 7 commonly recognised as of an active or volitional character, he classes as a part of Emotion. Sir William Hamilton, in remarking on the arrangement followed in the writings of Dugald Stewart, states his own view as follows : — ' If we take the Mental to the exclusion of Material phenomena, that is, the phenomena manifested through the medium of Self-consciousness or Eeflexion, they naturally divide themselves into three categoi'ies or primary genera ; — the pheno- mena of Knoioledge or Cognition, — the phenomena of Feeling or of Pleastire and Pain, — and the phenomena of Conation or of Will and Desire.' Intelligence, Feeling, and Will, are thus distinctly set forth. The mutual solidarity of the fundamental attributes of Mind has been variously stated. Some have aftirmed it in the form of absolute and inseparable co-existence, like length, breadth, and thickness in a material body. Thus, according to Hamilton — ' Thought and Volition can no more be exerted apart than the sides and angles of a square can exist separately from each other '. X second question relates to the priority of the different powers in the order of dependence or causation. Upon this, a decided position is taken by Hamilton, as v^ell as by the Germans, in favour of the primacy of Cognition or Thought, from which the others are derived or educed. The full discussion of this matter raises other questions of a fundamental character. See Note A. So far we have been dealing with the fundamental notions of Mental Science, as expressed in the highest generalities yet reached. It remains that we should briefly indicate the ultimate or foundation laws, axioms, or truths of the science, if any such are attainable. The Science of Mechanics follows up its Definitions with the Laws of Motion ; Chemistry commences with the Atomic Theory, which rules all that follows. As regards Psychology, the most fundamental and per- vading truths are these: — I. The Alliance of Mind and Body. 8 DEFINITION AND DIVISIONS OF MIND. The thorough-going concomitance of physical processes with mental is a law of all mind. It will be vindicated, once for all, in the next chapter (Brain), and will be un- folded in the detail as the exposition proceeds. II. Connected with each of the three powers, there are Jaws of more or less generality. (1) The Law of Kelativity, or the dependence of each state upon the state or states preceding. (2) The Law of Ketentiveness, which, although most identified with Intellect, is likewise essential to Feeling and to Will, both of which contain acquisitions and growths as a part of their nature. (3) The Law of Stimulus. There is here a general principle that the mental impres- sions due to outward stimulation of the Senses, are pro- portioned to the intensity of the stimulus in each case. This principle is modified by another, namely, the dimi- nution of the effect after continuance. These laws belong more especially to the treatment of Sensation. (4) The Laws of Mutual Action of the Three Powers. It has to be shown in detail, how Feeling, Will, and Thought act and re-act on each other. 5. In the plan of the present volume, Part first, entitled ' Movement, Sense, and Instinct,' will include the discussion of both Feeling and Volition in their lower forms, that is, apart from Intellect, or so as to involve Intellect in the least possible degree ; the Sensations of the different Senses will ibrm a leading portion of the contents. This division will cover all that is primitive or instinctive in the susceptibilities and impulses of the mental organisation. The second Part will aim at a full exposition of the Intellectual properties. Thus, while Feehng, Volition, and Intellect are regarded as the ultimate properties and the fundamental classification of mind, it is not proposed that the exposition should proceed strictly in the order thus stated. CHAPTEB II. THE NERVOUS SYSTEM. 1. A LTHOUGH Subject and Object (Mind and Matter) are -lA. the most diametrically opposite facts of om' experi- ence, yet there is a concomitance or connexion between mind and a material organism. This position is best sup- ported by the subsequent details. The parts of the human frame that chiefly concern the student of mental science are the Nerves and Nerve Centres (principally collected in the Brain), the Organs of Sense, and the Muscular System. The organs of sense and of move- ment will be described afterwards ; a brief description of the Nerves and Nerve Centres will occupy this preliminary chapter, in which we shall confine ourselves as far as possible to the facts bearing directly or indirectly upon Mind. 2. That the Brain is the principal organ of Mind is proved by such observations as the following : — (1) From the local feelings that we experience during mental excitement. In most cases of bodily irritation, we can assign the place or seat of the disturbance. We localise indigestion in the stomach, irritation of the lungs in the chest, toothache in the gums or jaws ; and when the mental workings give rise to pain, we point to the head. In ordinary circumstances we have no local consciousness of mental action, but in a time of great mental agitation, or after any unusual exertion of thought, the aching or oppression in the head tells where the seat of action is, precisely as aching limbs prove what muscles have been exercised during a long day's march. The observation can occasionally be carried much farther ; for it is found that a series of intense mental 10 THE NERVOUS SYSTEM. emotions, or an excessive strain on the powers of thinking will end in a diseased alteration of the substance of the brain. (2) Injury or disease of the brain iiupairs in some way or other the powers of the mind. A blow on the head will destroy consciousness for the time ; a severe hurt will cause a loss of memory. The various disorders of the brain, as inflammation, softening, etc., are known to affect the mental energies. Insanity is known to be accompanied by cerebral disease. (3) The products of nervous waste are increased when the mind is more than ordinarily exerted. The alkaline phosphates (triple phosphate of ammonia and magnesia) removed by the kidneys are derived principally from the waste of nervous substance ; and they are sensibly increased after great mental exertion or excitement. Phosphorus abounds more in the brain than in any other tissue. (4) There is an indisputable connexion between size of brain and the mental energy displayed by the individual man or animal. It cannot be maintained that size is the sole circumstance that determines the amount of mental force. But just as largeness of muscle gives greater strength of body, as a general rule, so largeness of brain gives greater vigour of mental impulse. The measurements of the heads of remarkable men ha\e often been quoted. ' All other cir- cumstances being alike,' says Dr. Shai-pey, ' the size of the brain appears to bear a general relation to the mental power of the individual, — although instances occur in which this, rule is not applicable. The brain of Cuvier weighed upwards of 64 oz., and that of the late Dr. Abercrombie about 63 oz. avoirdupois. On the other hand, the brain in idiots is. remarkably small. In three idiots, whose ages were sixteen, forty, and fifty years, Tiedemann found the weight of their respective brains to be 19f oz., 25f oz., and "22^ oz.; and Dr. Sims records the case of a female idiot twelve years old whose brain weighed 27 oz. The weight of the human brain is taken at about 3 lbs. (48 oz.).' (5) The specific experiments on the nerve cords and THE BRAIN THE ORGAN OF MIND. 11 nerve centres, to be afterwards quoted, have proved the im- mediate dependence of sensation, intelligence and volition on those parts. No fact in our constitution can be considered more certain than this, that the brain is the chief organ of mind, and has mind for its principal function. As we descend in the animal scale, through Quadrupeds, Birds, Reptiles,. Fishes, etc., the nervous system dwindles according to the decreasing measure of mental endowment. STRUCTURE OF THE NERVOUS SYSTEM. General View of the Nervous System. The Nervous System is divided into two parts — a central part and an internuncial part. The central part is the Cerehro-spinal axis, which includes the brain (or encephalon) and the spinal cord. These in turn are divided into special centres, and are, properly speaking, collections of centres. The internuncial part is the system of nerves. These are cords of gi'eater or less size and complexity, which connect the cerebro-spinal axis with the circumference (periphery) of the body. At the central end, these cords pass into the nerve centres, and form a part of the central system ; at the peripheral end, they are variously modified accord- ing to the parts that they supply. These modifications give birth to the motor, sensory, and other end-organs. Besides the cerebro-spinal axis and its nerves, there is a second system — the Si/vqxithetic — which connects itself intimately with every part of the other. The central part of the Sympathetic is a series of ganglia or small bodies of nerve matter, which lie principally to the right and left in front of the vertebral colunm. The internuncial part is a system of nerve cords, which pass from the ganglia to the viscera, and to the various parts of the cerebro-spinal system. Up till recently, physiologists regarded the sympathetic as essentially a separate system ; now they regard it as merely a part of the cerebro-spinal system, peculiarly modi- fied. The superficial resemblance of its disparate ganglia to the ganglionated nerve cords of some lower animals suggested the hypothesis that the sympathetic system is the true homologue of the nervous svstem of invertebrates. This hypothesis is now 12 THE NERVOUS SYSTEM. Fig. 1. Diagram of the Cerebro- spinal and Sympathetic Nerves (Ferrier). This diagram, composed and modified after figures by Quain, represents tlie spinal cord as seen from before. The spinal nerves are indicated by the Roman numerals : — ci-viii being the cervical nerves ; di-xii, the dorsal ; li-v, the Ivmibar, and the rest, not specially numbered, the sacral nerves. The plexiform arrange- ment of the nerves is seen on the left side. The brachial plexus is seen to be composed of branches from cv to di, with some communicating branches from civ to dii ; the lumbo-sacral plexus is seen to derive branches from LI to siv inclusive. The individual branches of these plexuses are indi- cated by letters and small numerals, but are not here named in detail. The sympathetic cord and ganglia are seen on the right side, with their jmic- tions with the spinal nerves, II, the superior cervical gan- glion ; b, the middle cervical ganglion ; cd, the inferior cervical ganglion, united with the first dorsal gan- glion; ,s^j, the great splanch- nic nerve ; .sjOo, the lesser splanchnic nerve ; d', the eleventh dorsal ganglion ; ,«, tlie upper sacral ganglion. NEEVE MATTER. 13 abandoned. The researches of Gaskell and others demonstrate that the sympathetic system is only a modification in the distri- bution of the cerebro-spinal nerves (Fig. 1). Grey and White Nerve Matter. To the naked eye the matter of the nervous system is of two kinds — grey matter and white matter. The gi'ey matter forms a large part of all nerve centres — of brain, of spinal cord, of ganglia. The white matter also forms a large part of the same centres, and forms almost the whole of the internuncial system. The grey matter of the centres distributes itself variously and in varying proportions through the white ; and a description of grey and white matter would be a naked-eye description of the nervous system. Under the microscope, nerve matter is found to consist of nerve cells or corpuscles and nerve fibres. These are the two structural elements of the nervous system. In the centres they lie embedded in a cement substance [neurogleia), whose structure is as yet undetermined. Nerve Cells, Nerve Corpuscles or Ganglionic Cells. Nerve cells (Fig. 2), named also ganglion cells or nerve cor- puscles, are found in the grey matter of the brain and spinal cord, in the sympathetic and other ganglia, in some of the nerves of special sense, and occasionally in the course of certain other nerves. They constitute a large part of nervous grey matter. ' Of the grey substance, Henle estimates that one-half is fibrous, the rest is partly cellular, partly amorphous ' (G. H. Lewes : Physical Basis of Mind, p. 252). A nerve cell is a small mass of protoplasm, with a nucleus and a nucleolus. The protoplasm is finely granular and sometimes indistinctly striated, brownish red in colour, and occasionally con- taining round the nucleus small accumulations of brown or yellow pigment-granules. The nucleus is a large, clear, rounded vesicle, containing always a distinct, highly refractile nucleolus and some- times an intra-nuclear network. The nucleus in some cases is the greater part of the cell. In shape, nerve cells vary according to the part of the nervous system that they belong to. Thus the cells from some nerve ganglia are spheroidal, from others spindle-shaped ; those from 14 THE NERVOUS SYSTEM. the sympathetic gangha are more angular ; those from the spinal grey matter are irregular ; those from the grey matter of the brain are spheroidal, or pyramidal, or flask-shaped. Cells have branch- ing processes, and sometimes take their names according to the number of processes — uni-polar, hi-polar, multi-polar. ' The number of processes given off by a nerve cell varies, but seldom exceeds five or six. Apolar nerve cells seem to be physiologically inconceivable. [This, however, only on the supposition that Fig. 2. A cell from the anterior horn of the spinal cord of the pike. 3Iagn. 150. A cell from the anterior horn of the hmnan spinal cord. Magn. 150. — a. Axis-cylinder process ; b, clmnji of pig- ment. A pigmented cell from the substantia fer- ruginea. Hu- man brain. Magn. 150. nerve impulses are not transmissible by other than recognisable cell processes or developed fibres. But see Mercier : Nervous System and the Mind, p. 43, and Foster: Physiology, 5th ed., p. 1025.] They are to be looked on either as developing cells or as artificial products. Eauber regards such apolar cells as arrested developments ; cells remaining in their original processless con- dition. It is difficult to understand the physiological value of unipolar cells, since, as a rule, their processes divide soon after NERVE CELLS. 15 ct-i they are given off from the cell. Many of them may, therefore, be looked upon as Ijipolar cells, the processes of which unite be- FiG. 3. Portions of two nerve fibres stained witli osmic acid A B (from a young rabbit). 425 diameters (E. A. S.) {Quain's Aaatomy). R, R, Nodes of Ranvier, with axis-cylinder passing- through, a, Primitive sheath of the nerve, c. Oppo- site the middle of the segment indicates the nucleus and protoplasm lying between the primitive sheath a.nd the medullary sheath. In a the nodes are wider, ^^ r and the intersegmental substance more apparent than in B. (From a drawing by Mr. J. E. Neale.) fore they join the cells. Eanvier has proved that this is the case with the cells [of the spinal ganglia] which have a single T-shaped process.' The finest ramifications of the processes join a nerve network from which again the branches are probably re-associated into thicker fibres clothed with medullary sheaths ' (Obersteiner : The Anatomy of the Central Nervous Organs, Eng. transl, p. 125). In size, nerve cells varv from ^i^^th to ^^igth of an inch. The differences of shape are probably incidents of development or mechanical surroundings ; the differences of size are probably correlative with some difi'er- ences in function. The size seems to varv in many instances directly as the length of the fibre proceeding from the cell, the longer fibre requiring a larger nutritive centre (Ober- steiner, op. cit., p. 1.30). From the minute size of nerve cells, and the large quantity of grey matter constituted by them, we must reckon their total number by millions. But for all their number is vast, the nerve cells have probably taken too high a place in speculative physiology ; their development and ultimate structure, their grouping and their relation to fibres, their 16 • THE NERVOUS SYSTEM. composition and the products of their activity— these have, none of them, yet arrived at a final demonstration, and, in the assigning of functions to the grey matter, no hypothesis will be adequate that does not require in the cells, in their inter-connexions or in their amorphous matrix, a gi'eater complexity of structure than the methods of microscopical research have yet been able to reveal. Nerve Fibbes. Nerve fibres are found in the white nerve matter of brain and spinal cord, and iri the nerve cords of the cerebro-spinal and sympathetic systems. They are of two kinds — meduUated nerve fibres and non -meduUated. MeduUated nerve fibres. — A meduUated nerve fibre consists of three parts, — the axis-cylinder, the medullary sheath, and the primitive sheath (Fig. 3). The axis-cylinder is a soft transparent thread in the centre of the nerve fibre. It runs continuously along the whole length of the fibre from central origin to peripheral distribution, giving no branches in its course, and forming no con- nexion with the other fibres of the nerve cord. It connects itself at the central end with the process (probably with one chief process) of a nerve cell ; at the peripheral end, with the peripheral end organ. The axis-cylinder is the one essential part of every nerve fibre. It is to be regarded as the direct continuation of a nerve cell process. It is made up of exceedingly fine fibrils — the 'primitive fibriUce of Schultze. These, embedded in a homo- geneous or finely granular cement substance, give to the axis- cylinder a longitudinal striation (Fig. 3). In diameter the axis-cylinder does not exceed yooVoo^^ °^ ^^^ inch. It is held that in cells the process that is to become an axis-cylinder of a nerve fibre can be distinguished from the other processes of the ceU. The meduUary sheath, or white substance of Schwann, forms a tube round the axis-cylinder. This sheath, largely fatty in com- position, is a homogeneous, highly refractile structure, giving to the nerve fil^re its double contour and tubular appearance. In the peripheral meduUated fibres, this sheath is interrupted at regular intervals — the nodes of Banvier. At those nodes the only covering of the axis-cylinder is the primitive sheath. The primitive sheath of Schwann forms a tube round the NERVE FIBRES. 17 medullary sheath. It is a thin, tough, homogeneous membrane, with nuclei placed at intervals along its inner surface. These nuclei, which occur between the nodes of Kanvier, are probably concerned in the development of medullated from non-medullated fibres (Eoss). The primitive sheath is not present in the nerve fibres of the brain and spinal cord : those fibres are sur- rounded by the medullary sheath alone. At the peripheral distribution of the nerve, neither the medullary nor the primitive sheath is present ; here the axis-cylinder branches into its ultimate fibrils, and these have no sheath. In size, medullated fibres vary. Physiologists divide them into large-medullated and small-medullated. As in the case of nerve cells, the difference in size is probably correlative with a difference in function.* Non-medullated nerve fibres. — The non-medullated or grey fibres are found in the branches of the sympathetic system and along with medullated fibres in the cerebro-spinal nerv^e cords. They form the gi'eat mass of the sympathetic system. The non-medullated fibres are pale, faintly striated and nucleated at frequent intervals. The nuclei are held by some to belong to a delicate sheath, corresponding to the primitive sheath of the medullated nerve fibre. Unlike medullated nerve fibres, the non-medullated fibres branch and unite with other fibres. There is no medullary sheath. Nerves. The nerve cords or nerves, which to the naked eye are white tissue cords varying in size from -^^ inch, or less, to half an inch, are collections of medullated fibres, of non-medullated fibres, or of both. The fibres, surrounded by delicate connective tissue [endoneurium) and supported by it, are collected into fioiiculi or small gi-oups ; and each funiculus is surrounded by * ' The qualit3'of its action as well as the size of the muscle fib'rc appears to iufluence the size of the nerve. The fibres going to the slowly-acting red muscles of the rabbit are smaller than the fibres supplying the more highly differentiated white muscles. Spinal motor and sensory fibres reach a diameter of about 20fi. (micromillimetres) in the dog (Gaskell). ]Medullated sympa- thetic fibres are usually from 2/x. to 2-5fx. in diameter' (Hill in Obersteiner, 0]). cif., p. 116). 2 18 THE XERVOrS SYSTEM. connective tissue {perineuriinn). The funiculi, which vary in size, are in turn collected into larger gi-oups, similarly supported and surrounded by connective tissue. These gi'oups, wrapped in a niembranoiis coat, more or less fibrous in structure, constitute a Fig. 4. Section of the internal saphenous nerve (human), made after being stained in osmic acid and subsequently hardened iu alcohol. Drawn as seen under a very low magnifying power (E. A. S.) (Quaiu's Anatomy). Ep, epineurium, or general sheath of the ner\'e, consisting of connective tissue bundles of variable size separated by cleft-like areolse, which appear as a network of clear lines, with here and there fat cells//, and blood-vessels v: jjer, funiculus enclosed in its lamellated connective tissue sheath (perineurium) ; cad, interior of funiculus, showing the cut ends of the medullated ner\-e fibres, which are embedded in the connective tissue within the funiculus (endon- eurium). The fat cells and the nen'e fibres are darkly stained by the osmic acid, but the connective tissue of the nerve is only slightly stained. nerve cord or nerve. The nerves and their funiculi Ijranch and unite with each other in every variety, producing thus, in several regions, a special plexus, e.g., the brachial or lumbar ; but in- NERVE GANGLIA. 19 dividual medullated fibres, however often they pass from one funicuhis to another in tlie same or another nerve cord, never unite with other medullated fibres, and never branch except at their peripheral distribution. At the central end, the fibres of the nerves join the grey matter of the nerve centres; at the peripheral end, they join the end organs of muscle, of skin, of the viscera, and of the special senses. Thus, through the nerves, there is complete continuity of connexion between the cei'ebro- spinal axis and every organ and region of the body (Fig. 4). Nerve ganglia. The nerve ganglia may be arranged into three great classes — the Spinal Gangha, which are small swellings on the posterior or sensory roots of the spinal nerves ; the Sympa- thetic Ganglia, which form two chains that run outside the spina column from top to bottom, and, last, the ganglia of special nerves — as the Gasserian Ganglion (fifth cranial nerve), the Sublingual and numerous others. All these are essentially groups of nerve cells embedded in connective tissue, and everywhere have branch con- nexions with the cerebro-spinal and sympathetic systems. They cannot be regarded as nerve centres proper ; they probably serve solely for multiplying nerve paths and for the nutrition of nerve fibres. So far we have regarded the anatomical nerve elements in isolation. We shall now consider them as they combine to form the enormous complications of the Nervous System — the Cerebro- spinal Axis, the Sympathetic Ganglion chains, and the Nerve Cords reaching to all parts of the organism. For the purposes of description, the Cerebro- Spinal Axis is divided into the following parts : the Spinal Cord, the Medulla Oblongata, the Pons Yarohi, the Cerebellum and the Cerebrum. Of these the first alone occupies the Vertebral Canal ; the others lie within the Skull. Everywhere in their bony case the various structures are invested by three membranous sheaths of connec- tive tissue : first, the Dura Mater, which lines the bony cavity : second, the Pia Mater, which du-ectl}'' covers the nervous matter, and everywhere sends inward processes that to a certain extent form a supporting framework, and at the same time are a high- way for the innumerable blood-vessels ; third, the Arachnoid, which lies between Pia and Dura, forming, with the Pia, the sub- 20 THE NEEVOUS SYSTEM. arachnoid spaces, and, with the Dura, the sub-dural spaces. These spaces are, by a special opening, continuous with the ven- tricles of the brain, which, again, are continuous with the central canal of the Spinal Cord. The Canal, the Ventricles and the Spaces are filled with a serous liquid, which acts as an internal and external pressure-cushion for the semi-fluid and ever-yield- ing contents of the skull and vertebral column. The volume of the brain varies with every variation of the blood supply. When the volume increases, the amount of serous liquid within the skull grows less, thus relieving pressure ; when the volume lessens, the amount of serous liquid increases, thus restoring pres- sure. In this way the delicate structures of the brain are secured against the destructive effects of sudden variations of pressure within the skull. The Spinal Cord. The Spinal Cord is essentially a colunm of Grey Matter em- bedded in a column of white, the grey so disposing itself in the white as to exhibit, in transverse section, an irregular grey cres- cent in each lateral half of the cord. The two crescents — their convexities being towards the centre of the cord — are united by a grey commissure, which contains the central canal. Each crescent, which is somewhat ' comma-shaped ' (Foster), has an Anterior Horn, giving origin to the Anterior (Motor, Efferent, or Centri- fugal) Eoot of the Spinal Nerve issuing at that part ; and a Posterior Horn, which receives at least part of the fibres from the Posterior (Sensory, Afferent, or Centripetal) Eoot of the same nerve. The Posterior Eoot has a small swelling or Ganglion — these ganglia being, according to some authorities, the true origin of the posterior fibres ; which thus are a junction between ganglion and spinal grey matter (Obersteiner : Anatomy of Central Nervous Organs, p. 32). The two nerve roots unite to fonii the Spinal Nerve proper, which is thus a compound structure. The White Matter, thus broken up by the grey, forms the rest of the cord ; the sub-divisions due, in each lateral half, to the crescent of grey being named respectively Antero-lateral, Postero- lateral, and Lateral White Columns. Farther, the two lateral halves of the cord are united by the White Commissure (see Fig. 5). The transverse section of the cord is thus two semi- THE SPINAL CORD. 21 circular white and grey masses, united by a narrow isthmus of white and grey ; the indentations leading to the isthmus being the Anterior and Posterior Fissures. The microscopic constituents of the Cord are briefly these : — First, the White Matter consists of large and small medullated nerve fibres, so embedded in neuroglia that each fibre has a canal precisely fitted to it ; the neuroglia constituting, along with the <;onnective tissue from the pia viater, a large part of the cord. Fig. 5. Spinal Cord (Quaiii). — In a the anterior surface of the cord is shown, the anterior nerve root being divided on the right. In b a transverse section of the cord is exhibited, showing the crescentic shape of tlie grey matter in the interior. 1, the anterior median fissure. 2, posterior median fissure. 3, anterior lateral depression over which the anterior nerve roots are seen to spread. 4, posterior lateral groove into which the posterior roots are seen to sink. The anterior column is included between 1 and 3 ; the lateral column between 3 and 4 ; and the posterior column between 4 and 2. 5, The anterior root. 5' in A = the anterior root divided. 6, the posterior roots, the fibres of which pass into the ganglion 6'. 7, the united or com- pound nerve. These nerve fibres run, in part, transversely, passing into and out of the grey matter, or from one side of the cord to the other ; in part longitudinally, passing into the grey matter higher up, forming continuous white tracts along the whole length of the cord. Through these white columns, which are sub-divisible into functional groups, the segments of the cord are connected witli one another, and with the higher centres in the skull. 22 THE NERVOUS SYSTEM. Second, the Grey Matter, its elements likewise embedded in neuroglia, contains large nerve cells (Fig. 6), certain smaller nerve cells, fine medullated nerve fibres, naked axis-cylinders, and certain non-niedullated nerve filaments that are either divided axis-cylinders or branching processes of the cells. The ' fine medullated ' nerve fibres and the other fine filaments form an ' interlacement of extreme complexity ' (Foster). Whether the fine filaments or branching cell processes are continuous or only in juxtaposition is yet doubtful ; but, in either case, the grey matter is practically a continuous mass from end to end of the cord, and thus provides in its complexity a mechanism correspond- ing to the immense range and variety of nerve activities. The cord gives origin to thirty-one pairs of nerves — the Spinal Nerves — which pass symmetrically from the right and left. Each nerve, made up from the two roots (Anterior and Posterior) al- ready described, and carrying wath it branches from the neigh- bouring sympathetic ganglion, passes to some definite region of the body. Thus from the cervical region of the cord, several pairs of nerves pass to the arms ; from the dorsal region, several pairs pass to the skin and muscles of the chest ; from the lumbar region, several pairs pass to the lower extremities. Similarly special nerves pass to the organs of the abdomen and pelvis. In this way from the spinal cord directly, from spinal branches pass- ing through sympathetic ganglia or from sympathetic ganglia directly, nerve cords pass to supply all the main parts of the body — the skin, the nuiscles, the blood-vessels, the joints and the complicated viscera of pelvis and abdomen (see Fig. 1). The Functional Tracts or sub-divisions of the spinal w4iite matter have been ascertained chiefly by three methods : first, developmental ; second, experimental ; third, pathological. In the process of growth, the nerve fibres of the white matter do not all receive their medullary sheath at the same time, and the appearance of the medullary sheath in the difi'erent parts of the cord always follows a definite order. By observ- ing this order, Flechsig was able to sub-divide the cord into a number of columns. Thus the external part of the anterior column had its fibres completed earlier than the internal part, and so on. These results were confirmed and inter- preted by the methods of experiment and pathology. When FUNCTIONAL TKACTS OF THE CORD. 23 certain parts of the brain are removed or sections made of the Uving cord, degenerations occur along certain tracts of the cord ; and similarly, pathological changes, occurring in paralysis or other nervous affections, follow certain definite tracts. The tracts of degeneration in both cases correspond with the tracts of Flechsig, Fig. 6. Diagram of transverse section of the Spinal Cord in up^Der lialf of the dorsal region (after Plechsig). C, Anterior commissure, rft', Fibres which pass from the vesicular column of Clarke (ir) to the direct cerebellar tract. F, Posterior horn. Figs. 6 and 10. Letters common to both : — Ft, Pyramidal tract of the lateral column. 7', Columns of Tiirck. dr. Direct cerebellar tract, ar. Internal portion of the anterior root-zone. ar' , External portion of the anterior root-zone. fi\ Posterior root-zone. G, GoU's columns. //•, Reticular formation of the spinal cord, a, Anterior grey horns of the spinal cord. and, by careful collation of the results of all three methods, physiologists are now able to sub-divide the white matter of the cord into several well-defined columns (see Fig. 6). The main functional tracts are as follows : — 24 THE NERVOUS SYSTEM. I. Descending Tracts. A. Direct Pyramidal Tract — lying in antero-lateral white column. B. Crossed Pyramidal Tract — lying in lateral white column. C. Antero-lateral descending — lying in anterior lateral white column. D. Descending 'Comma' Tract — lying in postero-lateral white column. II. Ascending Tracts. A. Direct Cerebellar Tract — lying in posterior part of lateral white column. B. Median Posterior Tract- — connected with posterior nerve root. C. Ascending Antero-lateral Tract — adjoining descending tract of same name. III. Tracts yet Undetermined as Ascotding or Descending. This forms remainder of w^hite matter (Fig. 6). The details of these system columns concern special treatises on physiology. It is here enough to say that all the defined functional groups of fibres can be subsumed under two main groups : first, Descending Fibres, affording a channel for outgoing or centrifugal impulses from the cortex of the cerebrum and other higher centres ; second, Ascending Fibres, affording a channel for all incoming, centripetal impulses on their way from the end organs to the higher centres. ' Thus, as far as we can see at present, the spinal cord consists of a series of segmental mechanisms with their respective afferent and efferent roots (the grey matter of the several segments being continuous along the cord) of encephalic ties of white matter between the several segments and the brain, of longitudinal commissural tracts connecting together the several segmental mechanisms, and of transverse commissures running lai'gely in the grey matter ' (Foster's Physiology, 5th ed, p. 901.) The Medulla Oblongata. At the margin of the Foramen Magnum, the gi'eat opening between the vertebral canal and the skull, the Spinal Cord THE MEDULLA OBLONGATA. 25 becomes the Medulla Oblongata. In shape the Medulla, which is limited above by the Pons Varolii, is somewhat like a cone with the base upward. It is an inch and a quarter long, about an inch broad at its widest part, half an inch at its narrowest, and in thickness from before backwards about half_|an inch (Fig. 7). The Medulla is, in the first place, a grand crossing for fibres passing between the Cord and the higher centres. On the surface, the anterior and lateral white columns of the Cord become the anterior pyramid and lateral tract respectively ; the posterior white column dividing to form the restiform body and j^osterior 'py7-amid. An additional small mass — the olivary body— lies on the lateral tract. In the depth, however, the anterior pyramid is found to draw fibres from two main sources : first, from the anterior white column — direct pyramidal tract ; second, from the lateral column of the opposite side — the crossed pyramidal tract (sec. 10). The crossing of fibres so involved is the decussation of the pyraviids. Of the fissures of the Cord, the anterior median ■ends blindly at the Pons ; the posterior median opens out to form the Fourth Ventricle, which is thus bounded at its lower pai't by the posterior pyramids. At parts corresponding to the altered position of the other fissures, nerve roots issue as in the Cord. The Medulla is, in the second place, a collection of centres, that is, of special masses of grey matter. By the changes in the \vhite matter the grey matter of the Cord is redistributed, and broken up into masses more or less isolated^grrey nuclei. Besides those naturally thus arising, many other nuclei are added, chiefly in the floor of the fourth ventricle. These nuclei constitute the proximate origin of many cranial nerves, of which some cor- respond singly to the anterior or motor root of a spinal nerve, some to the posterior or sensory root, and some to both roots. The gi'eater number of the cranial nerves have their proximate origin in the Medulla. Through the Medulla the System Columns or Tracts of the Cord, after the changes described, pass towards the higher centres. The direct pyramidal tract, the crossed pyramidal tract, and the antero-external tract, pass directly through the Pons Varolii to the Cerebrum. The postero-internal tract passes partly to the ^rey matter of -the Fourth Ventricle, partly to the Cerebrum. The postero-external tract and direct cerebellar tract pass by the 26 THE NERVOUS SYSTEM. restiform body to the Cerebellum. The posterior radicular zone and the remaining tracts of the lateral white column, pass to the Corpora Quadrigemina and Optic Thalami. Thus the Spinal Cord in all its parts, in its grey matter no less than in its white,, passes into connexion, direct or indirect, with all the great collections of grey and white matter in the higher nerve centres — with the middle brain, the basal ganglia, with the cerebellum,, and, finally, with the cerebrum. The Pons Varolii. Next above the Medulla Oblongata lies the Pons Varolii. In front, it rests upon the base of the skull ; behind, it forms part of the floor of the Fourth Ventricle, and, at its upper part, it forms- the anterior wall of the Aqueduct of Sylvius — the channel that connects the fourth with the other ventricles of the brain ; above ,^^ it overlies the Peduncles or Crura of the Cerebrum. The Pons, like the Medulla, is at once a grand crossing and a collection, of grey centres. The fibres are transverse and longi- tudinal. The transverse fibres, divided further into superficial and deep, connect the hemispheres of the Cerebellum, constituting the middle cerehellar peduncles. The longitudinal fibres, likewise superficial and deep, are the upward continuations of the fibres that pass from the Medulla to the Cerebrum. These, probably reinforced by others from the Pons itself, constitute, beyond the Pons, the Cerebral Peduncles. Some fibres decussate in the Pons. Among the fibres everywhere lie masses of grey matter, which give origin to some roots of cranial nerves (see Fig. 7). The microscopic structure both of Medulla and Pons presents. no marked difference from the structure of the Spinal Cord. The grey matter is distributed according to a more complex system. The Cekebellum. The Cerebellum, or lesser brain, rests on the posterior part of the base of the skull. In front of it lie the Medulla and the Pons. Lying above it, and separated from it by dura mater, are the occipital lobes of the Cerebrum. The Cerebellum, many times the size of the Medulla Oblongata, and larger than Pons and Medulla together, is a complicated mass of grey and white matter. It is divided into Jiemisjjheres, right THE CEEEBELLUM. 27 Fig. 7. View from before of the medulla ob- longata, pons varolii, crura cerebri, and other central por- tions of the encepha- lon (Allen Thomson). Natural size. On the right side the convolutions of the central lobe or island of Reil have been left, together with a small part of the anterior cerebral convolutions : on the left side these have been removed by an incision carried be- tween the thalamus opticus and the cere- bral hemisphere. I', the olfactory tract cut short and Ij'ing in its groove ; II, the left optic nerve in front of the commissure ; II', the right optic tract ; Tit , cut surface of the left thalamus opticus ; C, the central lobe or island of lieil ; Sy. fissure of Sylvius ; x X , anterior perfor- ated space ; e, the external, and /, the internal corpus geniculatum ; A. the hypophysis cerebri or pituitary body ; tc, tuber cinereum with the infundi- bulum ; a, one of the corpora albicantia; P, the cerebral peduncle or crus ; /, the fillet ; III, close to the left oculo-motor nerve : x , the posterior perforated space. The following letters and numbers refer to parts in connexion with the medulla oblongata and pons. PV, pons Varolii ; T, the greater root of the fifth nerve ; + , the lesser or motor root ; FI, the sixth nerve ; J''IJ, the facial ; Fill, the auditory nerve ; IX, the glossopharyngeal ; A', the pneumogastric nerve; XI, the spinal accessory nerve ; XII, the hypoglossal nerve: CI, the suboccipital or first cervical nerve ; pa, pyramid ; o, olive ; d, anterior median fissure of the spinal cord, above which the decussation of the pyramids is represented; c^, anterior column of cord; /■, lateral tract of medulla con- tinuous with, (7, the lateral column of tiie spinal cord. 28 THE NERVOUS SYSTEM. and left ; each hemisphere is divided into lobes, and each lobe into lamiuce. The lobes and laminae of one hemisphere corre- spond with those of the other, and unite with them, partly by the Pons, and partly by other commissures. The bi-lateral charac- ter of the nervous system, seen in its simplest form in the cord and Medulla, is thus visible also in the Cerebellum. A hemisphere on section exhibits a peculiar arrangement of grey matter and white. Round the margin there is a wavy and arborescent layer of grey matter, corresponding to the laminae. Within the gi'ey, lies a large mass of white matter similarly arranged ; wdthin this again lies a layer of gi'ey matter, which, in turn, contains a mass of white. Each lamina thus becomes a layer of white matter caught between two layers of grey. The Cerebellar laminae correspond to the Cerebral convolutions : both of them secure great surface with little bulk. The white matter passes from the hemispheres in three main bundles : the siqjerior peduncle passes partly to the Corpora Quadi'igemina, and partly by the cerebral peduncles to the Cere- brum ; the middle peduncle, uniting the two hemispheres, forms the transverse fibres of the Pons ; the inferior peduncle passes downw^ards to the Medulla, where it becomes the restiform iDody. Microscopic Structure of Cerebellum. In the grey matter of the Cerebellum the microscope reveals three layers : first, a mcAecular layer, near the surface ; next, a nuclear layer, bordering the central white matter, and, lastly, between the molecular and nuclear layers, a third layer — Pur- kiitje's Cells. The molecular layer is made up of very small cells, some nervous, others neuroglial in nature ; and of minute fibrils, which are, in part, the branchings of Purkinje's cells. The nuclear layer shows a fine fibrillar groundwork and innumer- able nuclei, probably, in part at least, nuclei of nerve cells. The third layer — Purkinjd's cells — is made up of a single row of large, flask-shaped, markedly-nucleated cells, which connect themselves l)y a large process (an axis-cylinder) with the central white matter, and send many branching processes into the molecular layer. The precise inter-connexions of these three complex layers is a matter yet to define. It is enough to say generally that, from its cells, the molecular layer sends processes inwards, THE CEREBRUM. 29 probably to join the central white matter ; next, that from its cells the nuclear layer sends processes outwards to ramify in the molecular layer ; and, lastly, that the cells of Purkinje send inwards a main process to join the white matter, and outwards a vast number of branching processes to ramify in the molecular layer. Whether the various fibrils of the three layers are in anatomical continuity with each other, and with the white matter, is uncertain, but for functional continuity their mere contact or inter-proximity is enough. The white matter, like white matter elsewhere, consists of medullated nerve fibres, which serve in part for incoming, in part for outgoing, nervous impulses. ' The presumption, therefore, is, that all the fibres of the white matter begin or end either in the cells of Purkinje, or the fibrils of the molecular layer " (Foster, Phys., 5th ed., p. 1024). It is noteworthy that the cerebellar grey matter shows in its minute structure no such local and -convolutional variations as the cerebral grey matter does ; the cerebellum thus presenting no gi'oss anatomical basis for local variations in fvmction. The Nervous System is now growing in complexity. The grey matter, equally with the white, is greater in bulk, and more intri- cate in arrangement ; the cells are more numerous, more varied in form, and richer in connexions ; the fibres fall in greater masses, and pass in larger bundles to form greater and more numerous commissures. The whole architecture of the system is more imposing ; and if from structure and disposition of parts alone we could venture to forecast functions, we should say that, in comparison of the spinal cord and medulla, the Cerebellum will be a generator of greater energies, a receiver of impressions more numerous and more varied, probably concerned in more complex activities, and probably a centre of control. The Cekebrum. The progress of research in the localisation of brain function, makes it advisable to describe the parts of the Cerebrum with some minuteness. The cerebral convolutions, long beyond the reach of experimental physiology, have at length begun to jaeld up their secret, and every year is adding largely to the detailed knowledge of their functions. 30 THE NERVOUS SYSTEM. The Cerebrum fills the greater part of the skull cavity. The anterior two-thirds rests on the base of the skull ; the posterior third overlies the cerebellum. From the Cerebrum at its under surface the cranial nerves pass to their distribution through the numerous openings of the skull, and the crura cerebri, or cerebral peduncles pass downwards to become the longitudinal bundles of the Pons. On the upper surface, the Cerebrum is rounded, taking the general shape of the skull ; and, regarded from above, it is a, mass more or less oval, with the greatest breadth opposite the parietal eminences. The whole Cerebrum is kept in position by membranes. One gvQdX fissure divides the Cerebrum into hemispheres, right and left ; other fissures divide each hemisphere into four main lohes — frontal, parietal, occipital, temporal ; minor fissures or sulci, divide the lobes into convolutions, which take their names from the lobes they belong to. The following is an account of the main Fissures : — The great Longitudinal Fissure, corresponding to a line drawn on the skull from the root of the nose to the occiput, separates the hemispheres completely, except at the middle two-thirds, where the corjnis callosum, and other commissures form an inter- hemispherical isthmus. The corpus callosum, lying in the depth of the fissure, one can reveal by pushing the hemispheres apart. On the apposed sides of the hemispheres lie convolutions of some importance ; part of these, experiment has connected with move- ment of the trunk muscle-groups. The Fissure of Sylvius, corresponding to a skull-line drawn from one inch behind the external angle of the frontal bone to a point a little below the parietal prominence, separates the frontal lobe from the temporal. By drawing apart the lips of this fissure one reveals the Island of Beil — an important part in affections of speech {Ap^iasia). Near this lies the third left frontal convolution or convolution of Broca, who first correlated lesions of this con- volution with a special form of aphasia. The Fissure of liolando, corresponding to a skull-line drawn from near the vertex to the line of the Sylvian fissure, separ- ates the frontal lobe from the parietal. The convolutions of the ■* Eolandic area,' that is, those lying just in front and in rear of the fissure, contain the principal ' motor areas ' (Ferrier). CONVOLUTIONS OF THE CEREBRAL HEMISPHERES. Fig. 8—1. FRO N_Ta (. 31 LOBE '^al lobe. Diagram of the Oyri (convolutions) sulci (Fissures), on the lateral surface of the Right Hemisphere of Man (Gowers). Fig. H— 2. F.Tiolando TEMP ^^' The same on the Mesial Surface (Gowers). In both figures, the sulci are indicated by italic and the convolutions by roman type. The following list of some synonyms may perhaps be of use in connexion with these figures. Gjjri, or Convolutions. Precentral or anterior central = ascending frontal. Postcentral or posterior centi-al = ascending parietal. Superior temporal = infra- marginal = first temporal. Triangular lobule = cuneus. Central lobe = Island of Reil. Paracentral lobule = the mesial face of the superior frontal, within the marginal gyrus. Cingulum = the part of the gyrus fornicatus which adjoins the ■corpus callosum. Gyrus Hippocampi = uncinate gyrus, though the latter name is sometimes restricted to the front part of the hippocampal gyrus ; the two may be considered as a continuation of the gyrus fornicatus, and the three together, forming a series, have been called ' the great limbic lobe '. Sulci or Fissures. Central = Rolandic, or of Rolando. Perpendicular = parieto-occipital. Parietal = in traparietal or sometimes interparietal. Temporo-sphenoidal lobe = temporal lobe. 32 THE NERVOUS SYSTEM. The following are the main Lobes with their Convolutions : — The Frontal Lobe, lying in front of the fissure of Rolando, has- four main convolutions on the upper surface : the ascending frontal, just in front of the Rolandic fissure ; the first, second, and third frontals, extending forwards at right angles to the ascending. On the under surface there is a further unimportant division and a sulcus accommodates the trunk of the olfactory nerve. The Parietal Lobe, lying just in rear of the Eolandic fissure,. has three main convolutions : the ascending parietal, like the ascending frontal ; the upper parietal or supra-marginal ; the lower parietal or angular. The Temporal Lobe, lying below the parietal, is di\'ided hori- zontally into five convolutions, numbered from above downwards ; first temporal, second temporal, and so on. The Occipital Lobe, lying behind the parietal, has three con- volutions, numbered from above downwards ; first occipital, second occipital, third occipital. To exhibit the remaining convolutions, it is necessary to push the hemispheres apart, when, on the apposed surfaces, there become visible the calloso-marginal fissure ; this separates the marginal convolution from the gyrus fornicatiis , which rests on the corpus callosum. Behind these are the quadrate lobule and the cuneate lobule, with fissures corresponding. The base of the Cerebrum (Fig. 7) presents certain important structures — the Cranial or Cerebral Nerves. ' The deep origin or point of connexion of the cranial nerves with the brain is still, in some instances, a matter of uncertainty. It seems probable that each of the nerves arises from some special centre of grey matter, termed a nucleus : at all events, many of them can be traced to such special nuclei, through which, no doubt, they are connected with other portions of the cerebral mass ' (Gray's Anatomy, 10th ed., p. 506). These nuclei or deep origins must be regarded as of two orders : first, proximate ; second, cortical. For the cerebral nerves do, for the most part, belong to two orders of mechanism : a lower order, — the lesser grey centres, that is, the basal ganglia, middle brain and spinal cord ; a higher order, greater in complexity, and less defined in situation than the other — the higher grey centres, that is, the convolutions of the cerebral cortex. As parts of the first mechanism, the cerebral THE CEREBRAL NERVES. 33 nerves may act through the proximate nuclei, which are centres for circumscribed actions, as winking, or swallowing. Such actions will be reflex. As parts, however, of the second mechan- ism, which must subsume the first, the cerebral nerves must sub- serve all the activities of the highest centres of the brain. And the normal action of the cerebral nerves involves the integrity ahke of the proximate and of the cortical nuclei. Thus the Optic Nerve is traceable not only to proximate nuclei in the corpora quadrigemina, but to all the main lobes of the cerebral cortex as well— a striking instance of the large anatomical basis required for a sense of such vast importance to the organism. Orthe Cerebral Nerves (Fig. 7) there are twelve pairs, named in order as follows : First, the Olfactory, or nerve of Smell (sensory) ; Second, the Optic, or nerve of Sight (sensory) ; Third, the Oculo-motor, which gives branches (motor) to all the muscles that move the eyeball, except two — the superior oblique and the external rectus ; Fourth, the Trochlear, which supplies the superior oblique muscle of the eye (motor) ; Fifth, the Trigeminal, which has two roots — [a) a sensory root, passing through the Gasserian ganglion and supplying common sensibility to the face, the fore part of the head, the eye, the nose, the ear, the mouth, the larger part of the tongue, which last may possibly have some taste fibres from the same root ; (h) a motor root, which supplies chiefly the muscles of mastication ; Sixth, the Abducent, which supplies the external rectus muscle of the eye (motor) ; Seventh, the Facial, which is the ' principal motor nerve of the head, supplying all the superficial and several of the deep muscles ' (Quain) ; Eighth, the Auditory, or nerve of hearing (sensory) ; Ninth, the Glossopharyngeal (sensory and motor), which is (a) nerve of taste for the posterior third of the tougue, the lateral part of the soft palate, and the glossopalatine arch ; (h) nerve of common sensation for the posterior third of the tongue and for parts of palate, pharynx and epiglottis ; (c) motor nerve for some pharyngeal muscles ; Tenth, the Vagus, or Pneumogastric, which, with its enormous number of branches, sensory and motor (some inhibitory), is the channel of regulation for the respiratory, cir- culatory and digestive systems ; Eleventh, the Spinal Accessory, which ' supplies the Vagus with most of its motor fibres and also its cardio-inhibitory fibres ' (Landois) ; Tivelfth, the Hvpo- 3 34 THE NEEVOUS SYSTEM. glossal, which is the motor nerve for all the muscles of the tongue. Hitherto we have confined ourselves to the surfaces of the Cerebrum. We now advert to the internal structures. First : The cerebral grey matter arranges itself in two great divisions — first, the cortical grey matter, which forms a covering of fairly constant thickness for the whole surface of the Cerebrum ; second, the grey matter of the Basal Ganglia (Corpora Striata and Thalami Optici), the Corpora Quadrigemina, the Corpora Geniculata, the Pineal Body, the grey matter of the Aqueduct and several other masses of grey matter situated variously about the base and the ventricles. Of these, the chief are the Thalami Optici, and the Corpora Striata. Those bodies are in pairs — the Corpora Striata (divided into Caudate Nucleus, and Lenticular Nucleus) lying farther forward than the Thalami Optici and the whole four bodies embedded in the cerebral hemispheres. These four bodies are connected upwards, through the hemis- pherical white matter, with the grey matter of the cortical envelope ; downwards, through the Crura Cerebri, with the Pons, the Medulla, and the Spinal Cord ; horizontally, through the Commissures, with each other. Farther, the cortical envelope of one hemisphere is connected through the Corpus Callosum with the cortical envelope of the other. In the lower animals, the basal ganglia are proportionally more developed than in man, in whom the cortical envelope is much developed ; and in the exposition of functions, it wnll become evident that the basal ganglia in man are somewhat in the position of an instrument — a lesser brain, for the more highly developed cortical envelope to play upon. Into the minute structural localisation and relations of all these grey masses, it is not necessary to enter ; for our purpose, it is enough to state the general proposition that all the grey masses are inter-related by means of the white matter, which is chiefly made up of nerve fibres. Thus not only are different lobes of the brain connected ; but also different convolutions on opposite sides, and on the same side : and that too so inti- mately that there is no difficulty in imagining the whole brain working as a single organ in spite of the probable division into special centres. INTERNAL STRUCTURES OF THE CORTEX. 35 Microscopic Structure of the Cerebral Cortex. A section of the Cerebral Cortex (Fig. 9), made vertically to the surface, presents under the microscope a peculiarly rich con- glomerate of nerve cells, nerve fibres, nei've fibrils and neuroglial bedding. The cells vary so much in size and shape as to be fairly capable of classification according to these qualities, and they are so arranged as to form, parallel to the cortical surface, several layers of more or less equable distribution, certain classes of cell predominating in the Rolandic Areas (or Motor Areas), certain others in the Occipital Area, and certain others in yet other areas. It is necessary, however, to say that the microscopic analysis of the cortex has not as yet made it possible to isolate and define, by microscopic structure alone, regions of known functional differences. The approximation to this structural definition of 'Motor,' 'Sensory' and Compound regions must be taken with the qualification that, in large and important regions of the cortex, a diffused, not a specific, arrangement of cells is constantly found. And the transition from one predominating system to another is very gradual. * The chief varieties of the Cortical Cells are — Large Pyra- midal, Small Pyramidal, Angular, Fusiform, Granular or Nuclear, and lastly Irregular cells. These cells, a typical section of the cortex would exhibit in the following layers, from the surface inwards — First : Layer of irregular cells, embedded in neuroglia, cells being very infrequent and the whole layer being probably non-nervous in character. Second : Layer of small pyramidal or angular cells. Third : Large pyramidal cells in groups. These cells pre- dominate in the motor regions. Fourth : Granular or Nuclear layer, predominating in the Occipital region, which is sensory. Fifth : Fusiform layer. The local variations from this type are impressive enough to justify one in saying that the hypothesis of functional localisa- tion receives from them a general support. But the connexion * Bevan Lewis, Mental Diseases, p. 60 ct scq. ; Ferrier, op. cit., p. 41 ; Foster, op. cit., p. 1031. 36 THE NERVOUS SYSTEM. Fig. 9. I\Iotor. mm ■>, Via- /.yij -t !'.< V < ^ J •i 5 Cortex cf Motor Area of Brain of Monkey. ( x 147, Bevan Lewis.) — 1, First or peripheral layer. 2, Second layer, small angular cells. 3, Third layer, large pjramidal cells. 4, Fourth layer, ganglionic cells and ' cell clusters '. 5, Fifth layer, spindle cells. Sensory. >2 W0A ■V- jp-i'- *ii'-u /\ Cortex of Temporal Lobe of Monkey. ( X 147, Bevan Lewis.) — 1, First or peripheral lajer. 2, Second layer, small angular cells. 3, Third laj'er, pyramidal cells. 4, Fourth layer, granular stratum. .5, Fifth layer, ganglionic cells. 6, Sixth layer, spindle cells. FUNCTIONS OF THE NERVOUS SYSTEM. 37 •of cell and fibre cannot be made out in every class of cell ; we must assume that there are many white fibres that end in other ways than in cells, probably in some kind of network or inter- lacement. This makes it necessary to reconcile any theory of nervous cell action with the absence of direct fibrous connexion ; but at the same time enables us to conceive of the brain as an infinitely complex and continuous structure, capable of acting as a single organ (Foster, 5th ed., pp. 1069 and 1033). Functions of the Nervous System. In the most general sense, the nervous system is the means of regulating and redistributing the bodily energies. Without a nervous system, the eyes are blind, the ears are deaf, the limbs are motionless ; there is no sensation and no movement. That the eyes may see, nerve impulses, generated by impressions of light on the retina, must pass along the optic nerve to the matter of the grey centres, there to produce in nerve cells, nerve fibres or intercellular matrix, changes that are constant concomitants of sensation. The muscles, again, building up their contractile substance fi*om the complex chemicals of the blood, so lay up a store of energy ; but that the muscles may contract, nerve impulses, generated in the nerve centres, must pass along the motor nerves to the muscles, there to initiate the change from potential energy to kinetic. The organs of sense, the organs of movement, and, in a general way, the organs of nutrition, all have their representation in the nervous system. Nor this alone; for the combined sense activities of diiiferent senses, the combined motor activities of groups of muscles and the multiform co-ordina- tions of sense and movement everywhere, have their central representation on nervous grades of gi-eater and greater com- plexity. For the infinite complexities of regulation and redistribu- tion thus involved, two things are essential : first, the storing of nervous energy for graduated issue according to the various sensory, motor, or nutritive activities ; second, the transmission of nerve energy to and fro between one nerve centre and another, and between the nerve centres generally and the peripheral organs. The first is the special function of the grey or cellular matter ; the second of the white or fibrous matter. 38 THE NERVOUS SYSTEM. Functions of Grey Matter. The only definite structures of the grey matter are the nerve cells and nerve fibres. It is not improbable, however, that the structureless intercellular substance — the neuroglia, which forms, so large a portion of the total grey matter — plays some obscure part in the transmission of nerve energies. What its function is, physiology has not yet finally declared. Nor even is its ana- tomical identity as yet more than a plausible hypothesis. More than one substance seems to be included under the same name (Obersteiner : The Anato?ny of the Central Nervous Organs, pp. 154-5). Nerve cells. — The functions of the nerve cells are not every- where the same ; nerve cells as they vary in situation and struc- tiire vary also in function. In the Posterior Eoot ganglion, nerve cells, attaching themselves by a single process (unipolar cells) to the fibres of the posterior root of the nerve, constitute for those fibres a relay of nerve matter connected in some obscure way with the nutrition of the nerve. In Sympathetic Ganglia, again, where the cells are multipolar and branch irregularly, a fibre, passing to the cell as a medullated fibre, issues from it, by the cell processes, as a number of non-medullated fibres. The cell thus divesting the fibre of its medullary sheath and at the same time acting as a store of nutrition, probably multiplies the paths for nerve impulses, and so by a local mechanism secures the diffused action essential to the co-ordinated acti%dties of the viscera. Such a diffused distribution of nerve paths forms an intelligible physio- logical basis for one large group of sensations- — the organic sensa- tions (Gaskell : Journ. of Phys., vol. ix.). But so far as present knowledge goes, neither in the spinal, nor in the sympathetic ganglia, is the nerve cell anything beyond a source of nutrition or a local meeting place for nerve fibres of the same order : it does not act as a central connecting mechanism between two fibres of different orders (Foster : Physiology, 5th ed., p. 176). In the spinal cord, on the other hand, the nerve cell is a central connecting mechanism for fibres of different orders — for centrifugal and centripetal fibres. Centripetal or ingoing impulses passing to the cell are there reinforced from its store of nerve energy, radiated in a thousand directions along the delicate pro- FUNCTIONS OF NERVE CELLS. 39 toplasmic nerve network, thus absorbed in the rearranging of cell molecules for storage and future issue, or again directed outward along an axis-cylinder process as a series of centrifugal or outgoing impulses. The cell thus acts as a centre — a store, that is, of potential energy capable of becoming kinetic on a given stimulus. At the same time it is a source of nutrition to the fibres issuing from it. Cells of this order are large, much branched, and every- where associated with umscular movements. They are, there- fore, named motor. In the so-called ' motor areas ' of the cerebral cortex, such large cells are constantly present, and them physiologists are inclined to regard as the true homologues of the spinal motor cells (Charcot). But hardly anywhere, probably not even in the spinal cord, does the connexion of centripetal and centrifugal fibres take place simply through a single motor or even a group of motor cells. Centripetal impulses pass first to a smaller cell, more rounded, and less branched, but connected directly or indirectly with the motor cells. These are named sensory cells. They occur in the cord and they constitute an overwhelming majority of the so-called ' sensory areas ' of the cerebral cortex. They are probably the receptive terminus of centripetal impulses, which here are stored, elaborated, reinforced, diverted, or, by intercellular paths, radiated to other groups of sensory or motor cells. Note. In thus assigning functions to the cell, we have assumed the specific nature of nerve energy, the possibility of storage and graduated discharge, and the marvellous complexity of structure and physiological process that make storage and discharge possible. Here we have little help from histology, which finds in cell and fibre a complexity, great as it is, but little adequate to the enormous range of nerve activities ; or from nervous chemistry, which as yet has to content itself with gross results ; or from physics, which requires in the cell unstable molecules of vast size and complicated form. But in a general way speculative physiology is able to coi'relate storage and discharge with the varying states of cell nutrition. The farther question — whether ' internal ' nutrition alone, unaided or unabetted by different nerve impulses, would ever result in ' discharge,' is still open, though the possibility of this seems to be the ' limiting value,' so to speak, of cortical spontaneity 40 THE NERVOUS SYSTEM. (see Foster, p. 1116, where the whole question is minutely argued). Functions of Nerve Fibres. The properties and functions of nerve fibres are less hypo- thetical than those of nerve cells. The comparative simplicity of the fibres, the occurrence of limited lesions in individual nerves of the living body and the possibility of isolated experimental study after excision, have resulted in certain generalities that we may accept as verified. And the propositions here set down cover to a certain extent the properties of nerve tissue generally. First. Nerves, like muscles, belong to the class of irritable tissues — tissues, that is, capable of responding in a special way to stimuli of different kiuds — mechanical, thermal, chemical, electrical. In nuiscle, irritability shows itself by a visible change of form — a contraction ; in nerve, there is no detectable change of form, but there is an obscure molecular change, producing, when the muscle is still attached to its nerve, a muscular contraction, and having an electrical change as a constant accompaniment. This molecular change is the nerve imindse. Unlike a muscular contraction, however, a nerve impulse gives rise to no chemical or thermal change that present methods can detect. ' In fact beyond the terminal results, such as a muscular contraction in the case of a nerve going to a muscle, or some affection of the central nervous system in the case of a nerve still in connexion with its nervous centre, there is one event and one event only which we are able to recognise as the objective token of a nervous impulse, and that is an electric change' (Foster, p. 128). Second. The electrical change accompanying a nerve impulse is the ' current of action ' or ' negative variation ' of the natural current. In a resting nerve, as in a resting muscle, there is .present a current that deflects the galvanometer needle in one direction ; in an active nerve, as in a contracting muscle, the current so changes that the deflection of the needles is reversed almost to zero. This is the 'negative variation' (Du Bois Reymond). But the pre-existence of the resting ctnrent is doubtful ; hence the non-committal name ' current of action ' (Hermann). The current of action, which like the nerve impulse travels in form of a wave, increases or diminishes its rate and intensity with the rate and intensity of the nerve impulse. Third. From the point of stimulation the nerve impulse travels in both directions. The proofs of this important proposition are many ; but one seems crucial. When a nerve, sensoxw or motor, is stimulated raidway between its peripheral and central ends, the current of action FUNCTIONS OF NERVE FIBRES. 41 passes equally through the central and peripheral parts. This can happen only if the nerve impulse travels equally in both directions (Rosenthal : Muscles and Nerves, pp. 218, 312). Fourth. A nerve is not equally excitable at all points ; the excitability is greatest at the central end. When, therefore, a motor nerve is stimu- lated far away from the muscle, the muscular response is more powerful than when the stimulation is nearer the muscle. From this fact Pfliiger inferred an avalanche-like increase of the nerve imjDulse during trans- mission ; the nerve thus forming an active, not a passive, conductor. The inference, however, is open to doiibt. ' It must at anj' rate be admitted that at one and the same point in the nerve the excitability may vary in degree, and it is therefore simpler to assume that the •difference in the results of irritating the nerve at varioiis points depends directly on differences in the excitability at those points, instead of being in the first place dependent on changes caused by transmission ; it can ■even be shown to be probable on various grounds, as indicated above, that the excitement in propagating itself through the nerve meets with resistance and is therefore rather weakened than strengthened' {Rosenthal : Muscles ami Nerves, p. 123). Fifth. To generate a nerve impulse the stimulus must be sudden. A resting nerve we may regard as a complicated arrangement of molecules ready to rearrange themselves on a given stinmlus ; but this rearrange- ment, that it may propagate itself along the nerve, must be suddenly induced. The well-miderstood fact of common life that a new sensation is most intense when it follows another sensation suddenly, has its coun- terpart in exact physiology. A continuous electric current passed through a nerve produces no contraction in the muscle except at the instant of making the current or breaking. On the other hand a faradic ■cm-rent, which is a rapid series of 'makes ' and 'breaks,' produces a corresponding series of contractions. Similarly with mechanical, ther- mal and chemical stimuli : these, to produce a nerve impulse, must act suddenly. This peculiarity of a nerve fibre is the physical counterpart to the Law of Relativity in the corresponding mental effects, but stimuli that singly are too feeble may produce a nerve impulse by their ■cumulative action. Sixth. The effect of a single stimulus is a single impulse ; now the voliintary contraction of muscle is known to be, not a single contraction, but a rapid series of contractions ; it corresponds to the state of sus- tained contraction (tetanus) produced in an isolated muscle by a series ■of stimuli appUed to the nerve. Voluntary contraction is in fact a tetanus. This it is easy to demonstrate : the steadiest hand trembles in activity ; the tremor of chronic alcoholism or of old age is only an exaggera- tion of the universal phenomenon. It must follow that the voluntary tremor is due either to some obscure peculiai'ity in the muscle itself or 42 THE NERVOUS SYSTEM. to the rapid recurrence of the nervous unpulses ; these in their turn- involve the rapidly recurrent discharge of the nervous centres. Certain investigators, arguing from the rate of tremor in voluntary contraction^ have fixed the rate of central discharge at ten to fourteen discharges per second. This, however, is hardly demonstrated by the results re- corded ; and besides, the assumption is rendered doubtful by the fact of the cumulative effect of feeble stimuli. Every line of argument makes it probable that the central nervous discharges are rhythmic ; but the rate of the rhythm is yet finally to be determined. Seventh. After prolonged activity, nerves, like muscles, show fatigue. Nerve impulses, hke muscular contractions, ai'e probably' explosive chemical decompositions of some sort ; fatigue in both probably coincides with the exhaustion, total or partial, of the explosive elements. In the resting state both muscle and nerve recover their explosiveness. In muscle, the decompositions and recompositions of contraction ai-e more or less definitely understood ; in nerve, however, the chemical or thermal changes are as yet inferences of analogy. Eighth. A nerve fibre camiot of itself initiate a nerve impulse ; such initiation requires a stimulus. In the normal body such stimulus may be initiation of the end organs of a sensory nerve, a direct impa'ct on the nerve trunk, sensory or motor, or tlie discharge of a motor cell or cells directly connected with the fibre. To take first the irritation of a sensorj- end organ. The nerve impulse passes inwards to the nerve centres and there caiises the discharge of the connected sensory cells. The discharge of these, should it spread farther, may cause discharge of connected motor cells. Of these, in turn, the dischai'ge initiates a nerve impulse along a nerve. And thus the motor discharge is directly sequent on the- peripheral stimulation ; and this is true of the majority of motor dis- charges. But the motor discharge may be independent of sensory stimulus. The discharge of a cell, like the passage of a nerve impulse, is probably an explosive decomposition of some sort — a katabolic or destructive process. Following on this is the state of rest, which is probably an anabolic or constructive process. And the effective life of a nerve cell is a continual alternation between these two, anabolism and katabolism. Now anabolism (construction, restitution, assimilation) depends directlj^ on the supply of nutriment, that is on the blood supply ; and it is safe to assume that in the anabolic process a point comes when the cell is liable to discharge either with a very slight stimulus from other nerve connexions, or simply with the excess of nutrition itself. In the latter case, the true stimulus is the Llood fluids. Tlie discharge of motor cells, therefore, follows naturally on the state of rest. The same is true of sensory cells. Nerve cells, therefore, are reservoirs of energy stored from the blood, and capable of graduated issue without the action of other nerve connexions. In this sense a nerve cell is automatic or FUNCTIONS OF THE SPINAL CORD. 43 spontaneous in its action ; and thus the charge and discharge, the ana- bolism and katabohsm of cells becomes an expression of the Doctrine of Spontaneity. This whole matter, however, must yet be regarded as among the non-verified assumptions of Physiology (see Foster, op. cit.y p. 1117). Ninth. Between fibres and cells the distinction is rather anatomical than physiological. The tj-pical nerve fibre is a process of a nerve cell, and even where this is not the case, there is no need to assiune a funda- mental qualitative difference in the activities of cell and fibre. Cell and fibre alike store and transmit nerve energy ; but the cell, from its greater size and more complicated build, is better adapted for storage, the fibre, for transmission. Functions of the Spinal Cord and Medulla Oblongata. The Spinal Cord, with the Medulla, may be looked upon, first, as a reflex mechanism, pure and simple ; second, as an executive centre for voluntary actions originated in the higher parts of the brain ; third, as a conducting path for all forms of nerve impulse, ingoing and outgoing. First. The three essentials of a reflex action are an ingoing stimulus or nerve impulse, a central discharge of nerve energy, and an outgoing nerve impulse to some motor end organ. In a frog whose higher centres have been removed by decapitation, the cord alone being left, stimulation of a limb by pinching or a drop of acid, is followed by the withdrawal of the limb. Here an afferent or ingoing impulse, initiated by stimulation of the skin, and conducted upwards by the sensory portion of the spinal nerve, passes, by the posterior root, to the grey matter of the cord. There, in some way not fully understood, the afferent im- pulse affects the cells, whose function it is to reflect, divert or radiate into new channels nerve impulses of whatever order. The cells, thus disturbed, initiate an efferent or outgoing im- pulse, which, passing outward by the anterior nerve root, ulti- mately reaches the muscles of the limb, and stimulates them to contract in co-ordination. The visible stimulus is pinching of the root ; the visible result is withdrawal of the limb — a co-ordinated muscular movement. Second. As an executive series of nerve centres, the cord is under the control and direction of the brain, which, from the enormous variety and delicacy of internal voluntary stimuli, is 44 THE NERVOUS SYSTEM. able to use the cord to carry out all classes of voluntary move- ment. In such cases the initiatory stimulus is from the brain. Third. As a conducting medium, the cord provides a path for all classes of ingoing impulses on their way to the higher centres, as well as to the higher parts of the cord itself ; and for all classes of outgoing impulses on their way from the brain to lower centres, or from the higher centres of the cord itself to the lower. The paths already described under Structure are the functional divisions of the cord as a conductor. Impulses, how- ever, also pass upwards and downwards in the grey matter. The Medulla Oblongata, in its actions, partakes of the same characters as the cord ; but in the medulla, or bulb, lie some of the centres most important to the life of the body, namely, centres regulating respiration and circulation. The respiratory centre in the medulla has long been held to be truly automatic — that is, capable of discharging energy into outgoing paths without any afferent or ingoing nerve stimulus, or any stimulus from higher or lower nerve centres. The bulb is a crow^ded collection of ever active nerve centres, and a thoroughfare ever crowded with nerve impulses from and to the higher centres. The classification of reflex actions and their significance in the mental life of the organism form the topic of a future chapter. Functions of the MicldU Brain and Cerebellum. The Middle Brain, which includes the masses that lie between the Medulla Oblongata and the Cerebral Hemispheres, may be regarded functionally as a single mechanism. It is certainly made up of parts that are anatomically distinguishable, but the specific differentiation of function has not proceeded so far as to make it possible to refer this or that phenomenon to this or that individual part. The mass as a whole, however, has certain constant functions, which are revealed when the cerebral hemis- pheres are removed. Such removal can be effected with complete success in the frog, with less success in the pigeon, and with still less success in the dog or other mammal. In the frog, totaJ ablation of the cerebral hemispheres without injury to the other parts of the brain, leaves the animal capable of all the actions of ordinary life, but deprives it of all initiative. The animal sits, hops, refuses to lie on its back, or avoids obstacles FUNCTIONS OF THE MIDDLE BRAIN. 45 Diagram of the Grey Masses of the Spinal Cord and Brain, sliowing the course of the (Conducting Paths (after Flechsig) (Ross). J{, Fissure of Rolando. ' P" P, T and /'(, Course of the fibres of the pyramidal tract from their origin in the central convolutions to their termination in the anterior grey horns («, a). I, II, III, First, second, and third portions of the lenticular nucleus (ifX). NC, Caudate nucleus. Th, Optic thalamus. D, C, B, A, Points from whicli fibres issue connecting the cortex of the brain and basal ganglion, and also the grey substance of the pons (fO). lid, Fibres connecting the cerebellum and optic thalamus ; and Ctyj, those connecting the cerebellum and the gi-ey substance of the pons. aq, and ;)'/, Anterior and posterior ])air of corpora qnadrigemina respectively. .(■, Upper, and .'', lower fibres connecting the olivai y body iiiid the corpora quadrigeniina. FR, Formatio reticularis of the medulla obhingita, "fornied liy tihres from the optic thalamus (270, the internal division of the interior ])eduncle of the cerebellum {icp), from the spinal cord (,rV, ar, and «/•'), and probably also from the clavate nucleus (i\V). 0, Olivary body; tcp, fibres of the restiform bodies connecting the olivary bodies and cere- bellum ; other fibres connect it with the triangular (Npr) and clavate (..Vi) nuclei. dp, Decussation of the pyramids. pr, Fibres of the posterior roots which pass upwards and down wanls into the grey substance, and pursue only a short course. a, a , a", o ", Anterior roots. p, pr, pr", G, Fibres of the posterior roots. 46 THE NERVOUS SYSTEM. placed in its way ; but all this only on stimulation. Similarly a pigeon flies when thrown into the air, or sits on the roost, or performs the other actions of its ordinary life ; but the initia- tive is gone. In mammals, the facts point in the same direction. The inference is threefold : first, that the power of spontaneous initiation or voluntary activity probably rests with the cerebral hemispheres; second, that the Middle Brain serves to co-ordinate, to regulate or to elaborate all the fundamental activities, sensory and motor ; third, that in the normal body the cerebral hemis- pheres exercise a persistent control, both initiatory and inhibitory, over the Middle Brain and the nervous mechanisms situated lower down. With the Middle Brain intact, however, it only needs the proper stimuli to induce all the complicated actions of the normal animal. ' The machinery for all the necessary and usual bodily movements is present in all its completeness. We may regard the share, therefore, which the cerebral hemispheres take in executing the movements of which the entire animal is capable, as that of patting this machinery into action, or of limiting its previous activity ' (Foster, p. 1001 ; Ferrier, p. 108, for full discussion of this problem in reference to facts and experiments). The co-ordinative machinery of the Middle Brain, with which for this purpose the Cerebellum may be associated, is liable to disarrangement from two sources : first, from disorder of certain afferent nerve impressions ; and second, from incisions, injuries, or diseases of the central machinery itself. First — Afferent Disorder. — The Middle Brain as a co-ordinative machine acts either at the instance of the cerebral hemispheres, or in response to afferent impressions. Impressions of vision, touch and muscular sensation, normally play a large part in this regulative stimulation ; but a residue of facts seems to indicate that, for the extremely delicate co-ordinations needed for the equilibrium of the body, the regulative stimuli proceed from the semicircular canals and labyrinth of the ear. Any disturbance of these — such as accretions pressing on the ear-drum, or disease of the petrous portion of the temporal bone, results in defective equilibrium of the body. Experiment gives a similar result. A leading symptom, too, of Meniere's disease of the ear is vertigo, or dizziness, which is the subjective side of disorder in some part of the mid-brain or its afierent nerves. A parallel series of facts ROTATORY MOVEMENTS FROM INCISIONS. 47 appears in locomotor ataxy, where the ingoing stimuli from the lower limbs are defective. Experimental vertigo due to visual impressions is readily produced by rapid rotation of the body with the eyes open. In every case the amount and sequence of nervous discharges necessary for co-ordination seem to be regulated or guided by afferent impressions from special end organs. Second —Central Disorder. — When the co-ordinative machinery itself is interfered with by operative incision, by injury, or by disease, the result is 'forced movement '. Thus, a one-sided incision of the crura cerebri, of the middle or inferior peduncles of the cerebellum, of the pons varolii, of the medulla oblongata, and even of the corpora quadrigemina and corpora striata (which last have been hitherto excluded from the middle brain), results in rolling or rotatory movements of the animal. Every effort or stimulus to act ends always in a persistent rotation of the body on its long axis. The same or similar lesions may produce ' circus ' movements, where the injured animal persistently •describes a circle, moving sometimes towards, sometimes away from, the injured side. Yet other varieties are the ' clock-hand movement,' the ' somersault,' and the ' rectilinear' movement. The hypothesis suggested by these singular manifestations is that there exists in permanence a powerful nervous stimulation to the muscles of the two sides of the body, such as would cause •an energetic propulsion of each. In the ordinary condition the two sets of stimuli are balanced, and produce an equilibrium, disturbed only by the slight remissions necessary for locomotion and other voluntary exertions. The destruction of the nervous tracts or centres on one-half of the body leaves a preponderance on the other ; and the one-sided movements that are seen in consequence testify how energetic the persistent current must be. If this be the true interpretation of the phenomena, we obtain from it a striking confirmation of the doctrine (to be afterwards adverted to) of internal or self-originated movements, as contrasted with the movements from outward stimulation. This hypothesis of continual discharge does not conflict with the hypothesis that, for complex co-ordinations in space, the discharge requires the guidance of ingoing impulses. Corpora Quadrigemina. — Chief among the individual ganglia constituting the Middle Brain are the Corpora Quadrigemina. 48 THE NERVOUS SYSTEM. They are in some way connected with vision, and probably with hearing ; but the precise part they play is not finally determined. They are reasonably to be regarded as part of the co-ordinative mechanism for sensations ; they probably elaborate or transmute visual impressions on their way to the motor centres, cortical or sub-cortical ; so forming, as it were, the ' court of first instance ' for these visual or other sensations that are concerned in motor and sensory co-ordination. Coiyora Striata and Optic Thalami. — The Corpora Striata and Optic Thalami serve, not only to multiply or diffuse the paths to and from the hemispheres, but also to innervate ' the same move- ments as are differentiated in the cortical centres, but of a lower grade of specialisation'. 'It is probable that the optic thalami, specially related to the sensory tracts, and the corpora striata, specially related to the motor tracts, represent in a subordinate manner all the sensory and motor centres of the cortex, and con- stitute together a sensori-motor mechanism, subservient to the manifestation of all those forms of activity which do not imply conscious discrimination or true volition. In proportion as the capa- cities and modes of activity transcend mere consensual or adap- tive automatism, and involve continuous discrimination and special motor acquisition, do the cortical centres become necessary, as in man. In such case the basal ganglia may be more or less com- pletely dispensed with, as would appear from the absence of permanent symptoms in case of lesions confined to the ganglionic substance proper. If, on the other hand, as in rabbits, the modes of activity do not greatly transcend automatism, the cortical cen- tres are of less importance, and may be removed without creating much obvious disturbance. In intermediate cases, as in dogs, the degree of disturbance caused by removal of the cortical centres will depend on the relative proportion in their modes of activity between mere automatism, provided for by the basal ganglia, and special acquisitions which have involved the use of conscious discrimination' (Ferrier, pp. 419 and 422). Cerebellum. — Of the Cerebellum, as unassociated with the Middle Brain, there is not much to say. Experiment has shown it to be intimately related to the equilibrium of the bodily movements. Lesions of certain parts of it result in disturbances similar to those already detailed under the Middle FUNCTIONS OF THE CEREBRAL CORTEX. 49 Brain, and the same classes of afferent impulses are found to be essential to the integrity of cerebellar action. Probably, if extent of anatomical relationship is to be any guide, the cerebellum must be held as related to the co-ordination both of sensation and movement in every variety. Some would regard it as the active centre of continued movements, such as the maintenance of posture, in contrast with the cerebrum, which initiates change of movement (Eoss). Others consider it the seat of co-ordination or elaboration for afferent impulses in general and for muscular sensations in particular (Gowers, Foster). Others regard it as a grand motor centre (Bastian). The grey matter of the cerebrum is connected with the grey matter of the cerebellum, but the precise interaction of those great bodies is difficult to define. Indeed, no one hypothesis covers all the facts known of the cere- belluin ; and it is even doubtful whether the cerebellum, like the corpora striata and optic thalami, is not a compound of several organs accidentally brought together in the course of develop- ment. Functions of the Cerebral Cortex. In the lower nervous centres — the cord, medulla, pons, basal ganglia — localisation of function is to some extent guided by ob\aous anatomical differences. These structures are all well- defined masses of grey and white matter, for the most part in obvious relation with definite organs or groups of organs. But in the higher reaches of the Cerebrum, in the Cerebral Cortex, there is no such simple division into isolable masses. Grey matter in convolutions the naked eye does distinguish ; but the convolutions have no constancy, no obvious connexion with any definite function. Microscopically the indications of sub- division are more marked ; constantly certain types of cell are aggregated in certain regions ; large pyramidal cells prevail in the Eolandic areas ; smaller orders of cell in the Occipital. There is no great hazard in assuming that the peculiar local aggregations indicate differences of function. The division into organs, in fact, is no longer a naked-eye, but a microscopic divi- sion. Even microscopic structure, however, carries us but a little way towards a differentiation of functional activities. Physiologi- cal experiment is needed as well as clinical research in the rough 4 50 THE NEEVOUS SYSTEM. experiments of disease ; and both orders of investigation have produced results that, if not in many cases iinal, yet justify a provisional hypothesis on the localisation of cortical functions. The'primary issue lies between two hypotheses : first, that in all its activities the whole cerebrum acts, that the cortical grey matter is but one organ of multifarious function, and that no part ■of it is separable in function from all the rest (Flourens) ; second, that the cerebrum may act in parts, that the cortical grej^ matter may be differentiated into definite functional areas, and that these, on stimulation or ablation or definite disturbance, are found to regulate and control certain definable functions of the organism. By the first hypothesis the cerebrum is a single organ ; by the second, it is a vast aggregate of organs, in relation with all the highest activities of the organism. It is the discovery of these particular areas or organs that constitutes the work of Locali- sation. In its simplest and most practical form the Doctrine of Locali- sation may be stated as follows : Certain limited areas of the Cortical Grey Matter are associated with certain definite movements ; certain other areas are associated with certain sen- sations. The movements concerned are roughly named ' volun- tary,' a designation that indicates a ' variable spontaneity ' of occurrence, and marks them off from movements due solely to the lesser grey centres. In like manner the sensations, being sensa- tions proper, are marked off' from mere excito-motor afferent impressions. The evidence for this Doctrine of Localisation is of two kinds : first, physiological experiment on the lower animals — chiefly dogs and monkeys ; second, actual cases of cerebral disease in man. First — Experimental Evidence. — Experiments onliving animals divide into two classes — Stimulation experiments and Ablation experiments. • Stimulation. — The Cortical Grey Matter, long regarded as insusceptible to stimuli, has at last been found to exhibit certain constant [phenomena under electric stimuli — galvanic or faradic. Thus, a current of moderate strength applied to the exposed sur- face of the brain in the upper part of the ascending frontal or ascending parietal convolutions (Eolandic Area), gives rise to cer- tain movements of the leg ; applied lower down, about the middle LOCALISATION OF FUNCTIONS. 51 of the Eolandic Area, it produces certain movements of the arm ; apphed still lower down, always on the surface, it produces cer- tain movements of the face and mouth. These movements are characteristic and constant ; they follow ahvays on stimulation of the given areas ; they are, so far as can be judged from animals under narcosis, the movements that make vip the voluntary life of the animal. And the areas of stimulation are often well-defined : it is possible so to localise the area of leg or arm as to foretell with certainty the movements that will follow stimulation. By this method, accordingly, given parts of the cortex have been sub- divided into Motor Areas. The Sensory Areas are determined chiefly by the next method. Ablation. — When, by excision, or the actual cautery, a cortical area, sensory or motor, is removed or destroyed, the phenomena constantly associated with that area disappear. Thus, total destruction of the Eolandic Area of the left hemisphere results in paralysis of the limbs and face of the right side of the body ; destruction of the leg area results in the disappearance of the characteristic leg movements ; and so with the arm, shoulder, face, trunk, on removal of their respective areas. The paralysis, however, is paralysis not of all, but only of voluntary, movements. Eeflex and automatic movements may still persist. In like manner ablation of sensory areas results in defect of sensation. Thus, removal of the certain temporal convolutions produces deafness ; removal of the occipital lobe and angular gyrus produces defects of vision. The particular results are not always so simple as the above general statement implies. For it has been found that the paralysis of move- ment is often temporary. In the case recorded by Munk destruction of the Eolandic Area resulted in temporary paralysis ; then the animal recovered, but his movements were clumsy and ill co-ordinated. But ultimately he seemed to recover complete voluntary competence. Re- moval of the opposite Eolandic Area in the same animal at a later period resulted in a series of events precisely parallel. These facts are hardly to be reconciled with any one hypothesis yet propounded. Cerebral Disease in Man. — The positive facts of pain, disease and injury in man, tend to confirm the general conclusions of the experimental method. The most fruitful orders of fact in this regard are the following : depressed fractures of the skull with 52 THE NERVOUS SYSTEM. definite motor symptoms ; meningeal or brain abscesser; ; localised haemorrhages, either from skull injury or diseased arteries ; local- ised tumours ; the facts of epileptic seizures, particularly ' Jack- sonian epilepsy ' ; aphasia. For the ends of localisation all such cases may be generalised into two classes : first, Positive, or discharging lesions, where the irregular production of seemingly voluntary movements indicates some unusual irritation or disturbance of the cortical nerve matter ; second, Negative or destructive lesions, whei'e the com- plete paralysis of certain movements indicates a total destruction of cortical nerve matter. When in each class the movements concerned are the same {e.g., movements of the arm), the Positive or discharging lesions correspond to the Stimulation method of experiment ; the negative or destructive lesions, to the Ablation method. General Besults. Neither the results of physiological experiment nor the rough verification of disease can be regarded as more than approxima- tions to the refinement of the actual working of the cortex : the most delicate movements induced by stimulation are yet far from ' the soft play of life ' ; but undoubtedly the evidence is enough to indicate a fundamental sub-division of function in the cortex, and justifies the supex'ficial mapping of it into certain definite areas. The exact interpretation of these areas is a separate question. (1) Motor Areas. — The motor areas cover the Rolandic Convo- lutions, that is, the Ascending Frontal and Ascending Parietal ; part of the First Frontal Convolution, and part of the Marginal ConvoUition, on the apposed surfaces. First, if the Rolandic Convolutions be divided horizontally into thirds, the upper third will be the chief motor area of the leg ; the middle third, of the arm ; the lower third, of the face, mouth, and tongue. Second, the leg area extends a little forward on the first Frontal Convolution, and downward on the apposed Marginal Convolution. Third, the motor area for articulate speech lies in the Third Frontal Convolution of the Left Hemisphere (Broca's Convolution). ('2) Sensory Areas. — Of the sensory areas, Vision occupies the superficial and apposed surfaces of the Occipital Lobe ; Hearing FUNCTIONAL UNITY OF NERVOUS SYSTEM. 58 occupies the First Temporal Convolution ; Smell probably occupies the hippocanipal gyrus. On the areas of the other senses there is no general agreement. Cutaneous Sensibility, however, is held, on the analogy of the monkey's brain, to occupy the convolution just overlying the corpus callosum (Gyrus Fornicatus). (3) Unassigned Areas. — The greater part of the Frontal Lobe is as yet unassigned either to definite movements or to definite sensations. In certain monkeys (see Foster, p. 1041) stimulation of certain areas of the Frontal Lobe is followed by certain move- ments of head or of eyes. As yet there is no parallel to this in man. Of Sensory Areas and Motor Areas alike, it is essential to remember that thejf represent, not organs, but activities of organs ; not senses and muscles, but sensations and movements (Hughlings- Jackson, passim). Synthetic Correlation. Functional Unity of Nervous System. The brief analysis now^ presented has shown the principal parts of the nervous system in isolation ; it remains to reassert their essential unity. Every part of the nervous system, so we have seen, is in direct or indirect organic relation with every other ; the interconnexions are so numerous and so intimate that parts widely separate may yet act at once and together ; and again the lower grades, the spinal cord for instance, are subject to the control and direction of the higher. Thus, in the execution of a voluntary movement, or in the receipt of conscious sensations, or in the diffused expression of emotion, the sub-cortical centres and paths are as essential to the result as the cortical centres and commissures. One aspect of the mechanism, as our analysis has shown, is emphasised in the cord, another in the middle brain, still another in the hemispheres. Nor this only ; but the whole system affects, and in some obscure way controls, the nutrition of the body — the digestive, the vascular, the glandular, and the other systems of the organic life ; and among the most potent to this end is the brain itself, which, too, is associated with the higher phenomena of voluntary movement and conscious feeling. Nor, again, does the division of the cortex itself into functional areas more conflict with the notion of the brain as a single organ than the separation into anatomical parts conflicts with the functional 54 THE NEKVOUS SYSTEM. unity of the whole body. The areas, hke the parts, bring certain aspects of the system into prominence, the cortex acting at once as central register and central exchange for all incoming and out- going nerve messages. But through every part there is afunctional continuity — lower centres modifying and directing higher, higher stimulating and controlling lower, and both in a whirl of per- petual inter action. And this inter active play of nerve effects, constructive and destructive, is the physical correlate of mental phenomena as in this work conceived. From the simple reflexes of the cord, through the complex elaborations of the middle brain to the final alchemies of the cerebral cortex, the rise is unbroken ; and no one part, but the whole system in its unity, shall we pro- perly regard as the nervous concomitant of Mind. MOVEMENT, SENSE, AND INSTINCT. w E now enter upon the exposition of Mind in the fnll detail. In the First Book, which is to comprehend Movements, Sensations, Appetites, and Instincts, I propose to deal with what may be termed the inferior region of mind ; the inferiority being marked by the absence of Intellect and cultivation in any great degree. This is the region wherein man may be most extensively compared with the brute, whose intelligence and education are comparatively small. When the powers of a superior intellect, and the example and acquirements of former generations, are superadded to the primitive sensations and instincts, there results a higher class of combinations, belonging to an advanced stage of the exposition. It will, however, be remarked as a novelty in the plan thus announced, that the Appetites and Instincts have been included in the same department as the Sensations. In the works of former writers on Mental Science, — as, for example, Beid, Stewart, Brown, and Mill, those portions of our nature have been included in the general group of ' Active Powers,' embracing Desire, Habit, and the Will. My reasons for departing froin the example of these eminent writers are the following. In the first place, the Appetites and Instincts are scarcely at all connected with the higher operations of intelligence, and hence do not require to be preceded by the exposition of the Intellect ; everything necessary to be said respecting them may be given as soon as the Sensations are discussed. In the second place, I hope to make it plain that the illustration of the Intellectual processes will 58 MOVEMENT, SENSE, AND INSTINCT. gain by the circumstance that Appetite and Instinct have been previously taken account of. Thirdly, the connexion of Appetite with Sensation is of the closest kind. Fourthly, as regards Instinct, I conceive it to be proper to render an account of all that is primitive in our nature — all our un- taught activities, — before entering upon the process of acqui- sition as treated of under the Intellect. In addition to these reasons stated in advance, I trust to the impression produced by the effect of the arrangement itself, for the complete justification of my departure from the plan of my prede- cessors. The present Book consists of four chapters. The subject of Chapter I. is Action and Movement considered as spontaneous, together vi^ith the Feelings and Perceptions resulting from muscular activity. Chapter II. comprehends the Senses and Sensations. Chapter III. treats of the Appetites. Chapter IV. comprises the Instincts, or untaught Move- ments, and also the primitive rudiments of Emotion and of Volition. These last subjects are necessary in order to complete the plan of the Book, which professes to exhaust the primitive germs, whether of Action or of Feeling, belong- ing to our nature, before proceeding to the consideration of intelligence and acquisition. In a complete scheme of the mind, the Intellect is properly placed midway between the instinctive and the cultivated emotions and activities, being itself the instrument for converting the one class into the other. ' C H A P T E K I. OF SPONTANEOUS ACTIVITY AND THE FEELINGS OF MOVEMENT. 1. rpHE feelings connected with the movements of the J- body through the action of the muscles are here constituted into a distinct class, differing from the sensa- tions of the five senses. They are often treated as proceed- ing from a Sense apart, a sixth, or Muscular Sense ; in which view they are enrolled under the genus Sensation. That they are to be dealt with as a group by themselves, no less than sounds or sights, is generally admitted. With regard, however, to the position of the group in the plan or arrangement of our subject, there is still room for difference of opinion. In my judgment, they ought not to be classed with the Sensations of the five Senses ; and I believe, further, that the consideration of them conveniently precedes the exposition of the Senses. Tbe reasons are these two : — namely, (1) that movement may take the start of sensation, and is so far independent of any stimulus from without ; and (2) that action is a more intimate and insepar- able property of our constitution than any of our sensations, and enters as a component part into every one of the senses, giving them the character of compounds while it itself is a simple and elementary property. These assertions require to be proved in detail; but, to this end, it is first advisable to notice briefly the mechanism or anatomy of the muscular organs. OP THE MUSCULAR SYSTEM. 2. Muscular Tissue. — ' The nuiscular tissue is that by means of which the active movements of the body are produced. It 60 THE MUSCULAR SYSTEM. consists of fibres, which are for the most part collected into dis- tinct organs called " muscles " ; and, in this form, it is familiarly known as the flesh of animals. These fibres, from a character- istic that they exhibit under the microscope, are usually denomin- ated " cross-striped " or "striated" : they are many of them under the control of the will, and are, hence, spoken of as " voluntary " muscles. Another kind of muscular tissue is disposed round the blood-vessels and most of the hollow viscera, often forming a distinct coat or coats to these. In this kind, the fibres do not exhibit the same cross-striated appearance, and they have, there- fore, been termed in contradistinction " plain " or " non-striated" muscular fibres. Most of these are entirely withdi'awn from the control of the will, and they are, consequently, termed involuntary. The muscular tissue of the heart, although having a cross-striated appearance, differs in many respects from that of the skeletal muscles ; it is, on this account, described separately, under the term " cardiac " muscular tissue. Muscular fibres are endowed with contractility, by virtue of which they shrink or contract more or less rapidly under the influence of certain causes capable of exciting or calling into play the property in question, and, for that reason, named stimuli' (Quain's Anatomy, 10th ed., p. 285). 3. Structure of Cross-Striated or Skeletal JJuscles. — ' The skeletal fibres are for the most part gathered into distinct organs or muscles of various sizes and shapes, but are most generally of an oblong form and fui'nished with tendons at each extremity, by which they are fixed to the bones.' ' The fibres are, in the first place, collected into bundles of greater or less thickness, — named fasciculi or laceiti. The fibres are parallel in the fasciculi ; and the fasciculi extend continuously from one terminal tendon to the other, unless, in those instances, like the rectus muscle of the abdomen and the digastric of the inferior maxilla, where the fleshy part is interrupted by inter- posed tendinous tissue. The fasciculi also, very generally, run parallel ; and, although in many instances they converge towards their tendinous attachment with various degrees of inclination, yet, in the voluntary muscles, they do not interlace with one another. ' 4. Fibres: their Figure and Measurement. — ' In shape, the fibres are cylindrical, or prismatic with rounded angles. Their STRUCTURE OF FIBRES. 61 diameter varies greatly even in each muscle, although, for the most part, a prevailing standard is found to exist in every muscle. The largest fibres, in human muscles, average about ^4^ (0"1 mm.) in diameter ; the smallest are only about one-tenth of that width.' Structure of the Fibres : sarcolemma. — 'A muscular fibre ma}^ be said to consist of a soft substance, enclosed in a tubular sheath. The latter is named the sarcolemma. When viewed by trans- mitted light, even with a comparatively low power of the micro- scope, the fibres, which are clear and pellucid in aspect, appear marked with parallel stripes or bands, alternately light and dark, passing across them with great regularity ; and this, not only at the surface, but, as may be seen by altering the focus of the micro- scope, throughout their substance also. In a moderately extended fibre, about eight or nine dark and as many light bands may be counted in the length of yoVo o^ ^^^ inch, which would give about _._i^_ as the breadth of each. The proper substance of the fibre presents, besides the transverse bands, an appearance of longi- tudinal striation. On separating the fibre with needles, espe- cially after hardening in alcohol, it may be broken up longi- tudinally into fine longitudinal elements of a rounded or angular section, which run from end to end of the fibre [muscle columns or sarco-styles). These particles may be termed sarcous elements' (Bowman). The further analysis of muscle discovers, in the contraction motion of the semi-fluid contractile substance of the sarcous ele- ments, many analogies to the amoeboid movements of protoplasm, and traces the striated appearances to very minute differences of structure and activity (ib., pp. 293, 294). 5. ' Nerves of Voluntary Muscle. — The nerves of a voluntary muscle are of considerable size. Their branches pass between the fasciculi and repeatedly unite with each other in the form of a plexus, which is for the most part confined to a small portion of the length of the muscle or muscular division in which it lies. From one or more of such primary plexuses nervous twigs pro- ceed, and form finer plexuses composed of slender bundles, each containing not more than two or three dai-k-bordered nerve fibres, whence single fibres pass off between the muscular fibres and divide into branches which are finally distributed to the tissue.' ' The branches retain their medullary sheath until they 62 SPONTANEOrS ACTIVITY. reach the sarcolemma, when the white substance abruptly ter- minates, while the neurilemma becomes continuous with the sarcolevima. . . . The axis-cylinder as it passes into the fibre forms a clear localised branched expansion which lies immediately under the sarcolemma. . . . The termination of the axis-cylinder is not a continuous plate . . . but appears when viewed from the surface in the form of an arborescent figure, the branches of which do not, according to Eanvier, anastomose. ... It would appear that in mammals each muscular fibre has but one terminal structure, and receives consequently but one nerve fibre. As, moreover, the fibres of a nerve undergo division, probably re- peated di\dsion, before ending, it follows that one fibre in a nerve root or trunk may supply several muscular fibres ' {ib., p. 350). The structure above described is the Motor End organ or plate. PROOFS OF SPONTANEOUS ACTIVITY. 6. We have now to consider the evidence that can be adduced for the existence of movements anterior to, and independent of, the sensations of the senses. (1) Among the functions of the spinal cord, as may be seen, is the pecuHar property denominated the maintenance of muscular tone. In other words, the muscles in the living body are alw^ays more or less on the stretch. The nerve stimuli that put them into action for the purposes of life are merely occasional, being for long intervals wholly in- termitted. There is, nevertheless, a residue of contractile energy w'hich never wholly disappears. Investigation shows that this is the result of an effluence of nervous force from the spinal cord, and has nothing to do with the stimulus supplied by our cerebral or mental operations. This proves that the nerve centres can, of themselves, send forth prompt- ings to action, and that we do not necessarily w^ait for influences originating in the outward senses and passing to the centres by the ingoing nervous currents. The only circumstance that seems to militate against the strict character of the supposition now made is the possible existence of an ingoing current from the muscles themselves PROOFS OF SPONTANEITY. 63 to aid or augment what seems the natural spontaneity of the cord itself. This may or may not be. The appearances point to a conjoined influence of purely central emanation, and of impulses by the afferent nerves belonging to the muscle. For the purposes of the present argument, this consideration is immaterial. The antithesis that concerns the questioQ at issue is between stimulation from the senses, properly so called, and stimulation independent of the senses, deriving its origin from the motor centres of the nervous system. (2) A still more specific example of purely central emanation is the permanent closure of the muscles named sphincters, which is also a property of the spinal cord. Without a perpetual central emanation, this property is inexplicable. (3) It is not altogether irrelevant to cite the activity maintained by involuntary muscles, as showing the existence of a mode of power originating with the nerve centres. Nervous influence is required for keeping up the circulation of the blood, the movement of the food along the alimentary canal, etc. ; all which points to an inward evolution of force, although modified by stimulation in the several organs. It may be said that, when the movements are once commenced, the completion of one may be a stimulus to the succeeding ; still the question would recur — by what force does the heart begin to beat ? Thus the notion of an initiative existing in the nerve centres is borne out by the tonicity, by the action of the sphincters, by the still more energetic movements of rotation, and by the analogy of the involuntary muscles. Seeing that the spinal cord and the other inferior ganglia are found capable of originating muscular contractions, we are entitled to suppose that the larger masses of the brain may be the sources of a much more abundant and conspicuous activity than these examples afford. The proofs that follow are intended to put in evidence the existence of such movements. (4) In wakening from sleep, movement precedes sensa- 64 SPONTANEOUS ACTIVITY. tion. If light were essential to the movements concerned in vision, it would be impossible to open the eyes. The act of wakening from sleep can hardly be considered in any other view than as the reviving of the activity by a rush of nervous power to the muscles, followed by the exposure of the senses to the influences of the outer world. The first symptom of awakening that presents itself is a general com- motion of the frame, i.e., a number of spontaneous movements — the stretching of the limbs, the opening of the eyes, the expansion of the features, — to all which succeeds the revival of the sensibility to outward things. Mysterious as the nature of sleep is, in the present state of our knowledge, we are not precluded from remarking so notable a circumstance as the priority of action to sensibility, at the moment of wakening.* But if this be a fact, we seem to prove, beyond a doubt, that the renewed action must originate with the nerve centres themselves. The first gestures must be stimulated from within ; afterwards, they are linked with the gestures and movements suggested by sense and revived by intelli- gence and will. The higher degree of permanent tension in the muscles when we are awake is owing partly to the increased central force of the waking states, and partly to the stimuhis of sensation. But, in all cases, the share due to the centres must be considerable, although it is difficult to esti- mate it when mixed up with sensational stimulus. Thus, the force that keeps the eye open throughout the day is, in a certain measure, due to the spontaneous energy that opened it at the waking moment ; for, that force does not necessarily cease when the other force, the stimulus of light, com- mences. * This is maintained by Aristotle [Physica, viii. 2). He says that these wakening movements come not from sense, but from an internal source. Some writers have taken the opposite view ; but they have not, so far as I am aware, adduced any decided facts in support of it. If we cannot establish an absolute priority of movement in the act of awakening, we may at least maintain that movement concurs with, and does not follow, the re- animation of the senses. EARLY MOVEMENTS OF INFANCY. 65 We are at liberty to suppose that the nourished condition of the nerves and nerve centres, consequent on the night's repose, is the cause of that burst of spontaneous exertion at the moment of awakening. The antecedent of the activity is physical, rather than mental ; and this must be the case with spontaneous energy in general. V/hen coupled with sen- sation, the character of the activity is modified so as to render the spontaneity much less discernible. (5) The next proof is derived from the early movements of Infancy. These I look upon as in great part due to the spontaneous action of the centres. The mobility displayed in the first stage of infant existence is known to be very great ; and it continues to be shown in an exuberant degree all through childhood and early youth. This mobility can be attributed only to one of three causes. It may arise from the stimulus of Sensation, — that is, from the sights, sounds, contacts, temperature, etc., of outward things. It may, in the second place, be owing to Emotions, —as love, fear, anger. Or, lastly, the cause may be Spontaneous energy. The two first-named influences, external sensation and inward emotion, are undoubted causes of active gesticulation and movement. But the question is, Do they explain the whole activity of early infancy and childhood ? I think not ; and on evidence such as the following. We can easily observe when any one is under the influence of vivid sensa- tion ; we can tell whether a child is acted on by sights, or sounds, or tastes. And, if the observation is carefully made, I believe it will be found that, although the gesticulations of infants are frequently excited by surrounding objects, there are times when such influence is very Httle felt, and when, nevertheless, the mobility of the frame is strongly manifested. With regard to inward feelings or emotions, the proof is not so easy ; but here, too, there is a certain character belonging to emotional movements that serves to discriminate them when they occur. The movements, ges- tures, and cries of internal pain are well marked ; so, plea- surable feeling is distinguished by the equally characteristic 5 66 SPONTANEOUS ACTIVITY. flow of smiles and ecstatic utterance. If there be times of active gesticulation and exercise that show no connexion with the sights and sounds or other influence of the outer world, and that have no peculiar emotional character of the pleasurable or painful kind, we can ascribe them to nothing but the mere abundance and exuberance of self-acting mus- cular and cerebral energy, which rises and falls with the vigour and nourishment of the general system. The activity of young animals in general, and of animals remarkable for their active endowments (as the insect tribe), may be cited as strongly favouring the hypothesis of spon- taneity. When the kitten plays with a worsted ball, we always attribute the overflowing fulness of moving energy to the creature's own inward stimulus, to which the ball merely serves for a pretext. So, an active young hound, refreshed by sleep or kept in confinement, pants for being let loose, not because of anything that attracts his view or quickens up his ear, but because a rush of activity courses through his members, rendering him uneasy till the confined energy has found vent in a chase or a run, We are at no loss to dis- tinguish this kind of acti\dty from that awakened bj^ sen- sation or emotion ; and the distinction is recognised in the modes of interpreting the movements and feelings of animals. When a rider speaks of his horse as ' fresh,' he implies that the natural activity is undischarged, and pressing for vent ; the excitement caused by mixing in a chase or in a battle is a totally different thing from the spontaneous vehemence of a full-fed and underworked animal. It is customary, in like manner, to attribute much of the activity of early human life, neither to sensation nor to emotion, but to ' freshness,' or the current of undischarged activity. There are moments when high health, natural vigour, and spontaneous outpouring, are the obvious ante- cedents of ebullient activity. The very necessity of bodily exercise felt by every one, and most of all by the young, is a proof of the existence of a fund of energy that comes round with the day and presses to be discharged. Doubtless, it OPERATION OF EXCITEMENT. 67 may be said that this necessity may proceed from a state of the muscles, and not from the centres ; that an uneasy craving rises periodically in the muscular tissue, and is transmitted as a stimulus to the centres, awakening a nerv- ous current of activity in return. Even if this were true, it would not materially alter the case we are labouring to establish — namely, a tendency in the moving system to go into action, without any antecedent sensation from without or emotion ftom within, or without any stimulus extraneous to the moving apparatus itself. But we do not see any ground for excluding the agency of the centres, in the com- mencing stimulus of periodical active exercise. The same central energy that keeps up the muscular tonicity, must be allowed to share in the self-originating muscular acti\dty. If so, the demand for exercise that comes round upon every actively constituted nature is a strong confirmation of the view we are now engaged in maintaining. Taking together, therefore, the initial movements of infancy, the mobility of early years generally, the observa- tions on young and active members of the brute creation, and the craving for exercise universall}^ manifested, we have a large body of evidence in favour of the doctrine of spon- taneous action. (6) The operation of what is termed Excitement like- wise corroborates the position we are now upholding. The physical fact of the excited condition is an increase in the quantity, or a change in the quality, of the blood in the brain. The mental fact is the increase of mental energy in all its modes. A stimulus applied in such a condition pro- duces a more than usual response ; and there is manifested an incontinent activity, irrespective of all stimulation. The outward movements are hurried and uncontrollable, the feelings are inore intense, the thoughts are rapid ; every mental exertion is heightened. ^Yhen the excitement rises to the morbid pitch, as in disease, or under the in- fluence of drugs, such as strychnine, there is an enormous expenditure of force, apart from any stimulation whatsoever : 68 SPONTANEOUS ACTIVITY. I the altered nutrition of the brain is the sole influence con- cerned. (7) As a further confirmation, it may be remarked that sensibility and activity do not rise and fall together ; on the contrarj', they often stand in an inverse proportion to each other. By comparing different characters, or the different states of the same individual, we may test the truth of this observation. The strong, restless, active temperament is not always marked as the most sensitive and emotional, but is very frequently seen to be the least affected by these influ- ences. The activity that seems to sustain itself, costing the individual almost no effort, being his delight rather than his drudgery, and very little altered by the presence or the ab- sence of stimulus or ends, is manifestly a constitutional self- prompting force ; and such activity is a well-known fact. It is one of the fundamental distinctions of character, both in individuals and in races ; being seen in the restless adven- turer, the indefatigable traveller, the devotee of business, the incessant meddler in affairs, in the man that hates repose and despises passive enjoyments. It is the pushing energy of Philip of Macedon and William the Conqueror. On the other hand, sensitive and emotional natures, which are to be found abundantly among men, and still more abundantly among women, are not active in a corresponding degree, while the kind of activity displayed by them is plainly seen to result more from some stimulus or object, than from an innate exuberance of action. The activity prompted by ends, by something to be gained or avoided, is easily distinguished from the other by its being closely adapted to those ends, and by its ceasing when they have been accomplished. He that labours merely on the stimulus of reward rests when he has acquired a competency, and is never confounded with the man whose life consists in giving vent to a naturally active temperament, or a superabundance of muscular and central energy. (8) Lastly, it will be afterwards shown that, without spontaneity, the growth of the Will is inexplicable. LOCOMOTIVE MEMBERS. 69 Regions of SporitaneouH Activity. 7. The muscles, for the most part, act in groups ; being associated together by the organisation of the nervous centres, for the performance of actions requiring concurrent movements. The Locomotive Apparatus is, perhaps, the most conspicu- ous of the vohuitary groups. This involves (taking vertebrate animals in general) the limbs — or the anterior and posterior extremities with their numerous muscles — and the trunk of the body, which in all animals chimes in, more or less, with the movements of the extremities. In the outbursts of spontaneous action, locomotive effort (walking, running, flying, swimming, etc.) is one of the foremost tendencies ; having the advantage of occupying a large portion of the muscular system, and thus giving vent to a copious stream of accumulated power. No observant person can have failed to notice instances where locomotion resulted from purely spontaneous effort. In the human subject, the locomotive members are long in being adapted to their proper use, and, in the meantime, they expend their activity in the dancing- gestures and kicking movements manifested by the infant in the arms of the nurse. The locomotive action agitates the whole length of the spine up to the articulations of the neck and head. The members concerned, however, have many movements besides, especially in man ; and these are found to arise no less readily. Thus, the movements of the arms are extremely various, and all of them may burst out in the spontaneous way. The grasp of the hand is the result of an extensive muscular endowment, and at an early stage manifests itself in the round of the innate and chance movements. The erection and bending of the body are outlets for spontaneous activity, — especially erection, which implies the greater effort. AVhen superfluous power cannot run into the more abundant opening of locomotive movement, it ex- pends itself in stretching the body and limbs to the extreme 70 SPONTANEOUS ACTIVITY. point of tension. The erection extends to the carriage of the head and the distension of the eyes, mouth, and features. The vocal organs are a distinct and notable group of the active members. The utterance of the voice is unequivocally owing, on many occasions, to mere profusion of central energy, although more liable than almost any other mode of action to be stimulated from without. In man the flow of words and song, in animals the outbursts of barking, braying, howling, are often manifestly owing to no other cause than the ' fresh ' condition of the vocal organs. The eyes have their independent centre of energy, whence results a spontaneously sustained gaze upon the outer world. When no object specially arrests the attention, the acti^^ty of the visual movements must be considered as mainly due to central power. In a person deprived of the sight of one eye, we find that eye still kept open, but not so wide as the other. The mouth is also subject to various movements, which may often be the result of mere internal power, as is seen in the contortions indulged in after a period of immobility and re- straint. The jaws find their use in masticating the food, but, failing this, they may put forth their force in biting things put into the mouth, as in children not yet arrived at the age of chewing. The tongue is an organ of great natural activity, being endowed with many muscles, and having a wide scope of action. In the spontaneous action of the voice, which is at first an inarticulate howl, the play of the tongue, com- mencing of its own accord, gives the articulate character to utterance, and lays a foundation for the acquirenient of speech. i\.mong the special aptitudes manifested among the lower animals, we find marked examples of the spontaneity of action. The destructive weapons belonging to so many tribes, are fre- quently brought into play without any stimulus or provocation, and when no other reason can be rendered than the necessity for discharging an accumulation of inward energy. As the battery of the torpedo becomes charged by the mere course of nutrition, and requires to be periodically relieved by being poured upon OBJECTIONS TO THE DOCTRINE. 71 some object or other, so we may suppose that the jaws of the tiger, the fangs of the serpent, the spinning apparatus of the spider, require at intervals to have some objects to spend them- selves upon. It is said that the constructiveness of the bee and the beaver incontinently manifests itself even when there is no end to be gained ; a circumstance not at all singular, if we admit the spontaneous nature of many of the active endowments of men and animals. The spontaneous activity is alv\^ays observed to rise and fall with the vigour and state of nutrition of the general system; being abundant in states of high health, and deficient during sickness, hunger, and fatigue. Energetic movements, moreover, arise under the influence of drugs and stimulants acting on the nerves and nerve centres ; also, from fever and other ailments. Convulsions, spasms, and unnatural excite- ment, are diseased forms of the spontaneous discharge of the active energy of the nerve centres. While the doctrine of Spontaneity, to the extent here con- tended for, has been accepted by many, it has been utterly re- pudiated by some authorities. As far as I am aware, no one has attempted to refute the foregoing arguments seriatim, so that I cannot discover where the weakness is supposed to lie, and, consequently, am not able to reconsider them with a view to abandon or modify such as are defective. The only serious hostile argument that I have met with is based on the theoretical absurdity of referring our conscious movements to a purely physical cause or antecedent. Dr. Martineau has advanced the objection in this form, — namely, that the doctrine assumes our movements to proceed from a ' psychological nothing '. Dr. James Ward expresses himself to nearly the same effect, in saying that it ' makes movement precede feeling instead of following it '. Whoever takes this very high ground on consideration of theory is bound to explain away all the cases where movements apparently arise without any previous feeling, or any known mode of consciousness whatever. This, to the best of my know- ledge, has never been attempted. 72 SPONTANEOUS ACTIVITY. The arguments that I have adduced, eight in number, are not all equally cogent and irrefragable. Several of them might be evaded, or be shown to be in themselves unsatisfactory, — although of concurrent value as pointing to the conclusion. Of natural healthy movements, perhaps the strongest case is parturition. This I have dwelt upon in The Emotions and the Will, p. 304, making use of the language furnished to me by Dr. Sharpey, who suggested the example as strongly confirming my position. The next argument in point of cogency is the action of drugs that induce tetanus of the muscles. In this case, also, antece- dent feeling is entirely absent ; the subject being wholly insensible, except to the muscular strain. Strychnine imparts a morbid stimulus to the motor centres, while the centres of sense, are, during tetanus, in abeyance. It is not essential to the doctrine of Spontaneity to maintain that no afferent current w^hatsoever coincides with the outgoing motor currents. What is contended for is as follows : — (1) That a feeling or conscious state is not an indispensable antecedent or cause of movements. Dr. Ward's position that feeling in all cases precedes movement is, therefore, met by a direct negative. (2) Although there may be a sensory or afferent stimulus when movements arise, the two have no relation of degree or intensity : the sensory stimulus may be of the feeblest kind, while the motory may be of any amount. Both physiologically and psychologically, there are two independent sources of movement evident ; the one growing out of the sensory or ingoing current, the other growing oat of the motory centres, irrespective of stiniulus from without. It is this absence of concurrent intensities, or regulated con- comitance of sense and movement, that imparts to the arguinents from infancy, and from young and active animals, an amount of cogency scarcely inferior to the instances of Parturition and Tetanus from strychnine. Of the same tenor is the example from the contrast between Activity and Sensitiveness in charac- ter. Allowance being made for the presence of feeble afferent currents along with efferent, in tonicity and in the permanent closure of the sphincters, the arguments grounded on these CLASSIFICATION OF THE FEELINGS. 73 examples harmonise with the general contention, and cannot easily be set aside. The bearing of the doctrine, as now qualified, on the Growth of the Will remains to be expounded under that head. The only other remax'k necessary at this stage is the following. It is a much discussed question, as will afterwards be seen, whether muscular sensibility accompanies the outgoing nervous currents or results exclusively from ingoing currents by sensory nerves. It will be maintained, at the proper place, that neither of these hypotheses has any strictly psychological bearing : our classification of the varieties of muscular feeling will be the same under either alternative. It may seem, however, that, in the foregoing arguments for spontaneous activity, the first of the two hypotheses is assumed as a part of the case and as essential to the argument. But this is not really meant, and the language is retained merely for convenience in the expression (see p. 79). THE MUSCULAR FEELINGS. 8. We are now brought to the express consideration of the first class of phenomena proper and peculiar to mind, — namely, States of Feeling. These we have from the outset recognised as one of the three distinct manifestations of our mental nature. To give a systematic and precise account of the states of human consciousness — a Natural History of the Feelings, — is one of the aims of the science of mind. Classifying and Describing the Feelings. In order the better to class and to delineate the feelings, we follow the example of the Natural History Sciences. The primary divisions are, to a great degree, marked out for us. This applies chiefly to the Senses : every Sense organ has a generic sensibility, under which we can distinguish species and sub-species. The Emotions are not so well demarcated physically ; but, by using all the aids that we possess, we can make out a •classification here also. For obtaining descriptive characters to the various species, 74 THE MUSCULAR FEELINGS. we start from the threefold partition of mind as a whole — Feeling^. Volition, and Intellect. A certain number of characters belong to the Feelings, viewed in their own proper nature : such are pleasure, pain, and intensity or degree. But, besides these, every feeling has a certain bearing on the Will, as a motive, or negation of motive ; from which circumstance a descriptive peculiarity may be derived. So with the Intellect. Inasmuch as the feelings play a great part in our intellectual operations, they may be compared, contrasted, and delineated oii this head also. Moreover, we have seen that the fundamental fact of mind is the union with the body. The Body is the medium of all the external manifestations of our mental workings. It is impossible to avoid noticing these indications, or to fail making use of them in our estimates of the feelings. Our choice of the best mode of bringing forward these characters must follow the nature of the case. In the feelings, as now treated, the bodily side is best given in advance, owing to the danger of confounding Body and Mind in places where they ought to be kept distinct. The Plan, as a whole, runs as follows : — Physical Bide. Bodily Origin. (For Sensations chiefly.) Bodily Diffusion, expression, or embodiment. Mental Side. I. Characters as Feeling. Quality, — i.e., Pleasure, Pain, Indifference. Degree : Intensity, or acuteness. Quantity, mass, or volume. II. Volitional characters. Mode of influencing the Will, or Motives to Action. III. Intellectual characters. Susceptibility to Discrimination. Retainability, or Persistence. Quality in Feeling means that all feelings, properly so called,, are pleasures, pains, or neutral in this respect. This is the character that each one's consciousness reveals with certainty. GEADATIONS OF INTENSITY OF FEELING. 75 Degree is attended with much more difficulty. It has to be circumvented in a variety of ways. The distinction between the acute and the massive forms of feehng, or between Intensity and Quantity, is borrowed from Heat and Electricity, and is strictly applicable to the case, — as will be seen in tlie detail of the Senses, more especially Touch, Hearincr^ and Sight. We are quite readily able to distinguish the two modes. The direct conscious comparison is made when two feelings are in close proximity, or immediately succeed one another. This is the ultimate criterion, and its delicacy varies with the indi- vidual constitution. In cognising subjective states, as well as in estimating the properties of the object world, there is probably a difference of sensibility between one person and another, although the amount of difference has not been reduced to measurement. The comparison may be made by memory ; as when a present feeling is measured by a past. This is still less accurate. A pleasure can be compared with the amount of pain that it submerges or neutralises ; and a pain in like manner. This is a considerable advance on the conscious comparison of the same quality. Still more important is the reference to the outward or physi- cal signs of feeling, which both estimate the quality and measure the degree with all the nicety of a visible appearance. This is an additional means of judging to the individual self, while making the state known and measurable to others. The signs are of two classes, — those that are strictly emotional and those that operate through the will. We shall resume the consideration of Degree, after pointing out the characters of Feeling as bearing on the Will and on the Intellect respectively. The Will is moved by Pleasure and Pain ; the two acting in opposite ways. Hence the manifested conduct is a criterion of the quality of the feelings, and also of their intensity, under all the advantages of objective measurement. In the meantime, we need to assign the signification of ' Special Characteristics '. Two feelings may be, to the best of our judgment, identical in Quality and Degree, and yet not identical in every respect ; 76 THE MUSCULAR FEELINGS, there may be a conscious difference that prevents their being confounded, or mistaken one for another. A given taste may be as pleasant or as painful as a given odour, and yet we recognise a distinction between the two ; being the distinction that holds all through the sensations of the two senses. So it would be with our Emotions. The leading kinds of Emotion, as Love and Hatred, would never be confounded, even though, in particular cases, there might be a substantial agreement in the Quality, as pleasure or pain, and an identity in the Degree or amount. An idiosyncrasy attaches to each in our consciousness, which makes their intellectual status, and gives them a place in the classifica- tion of the Feelings. Intellectual States. The intellectual characters of our feelings are primarily Dis- crimination and Remembrance, not without the accompaniment of Feeling on the emotional side as typified by pleasure and pain. Sense and Memory Images are the consummate type of our intellectual products. The gradations of merit or excellence attaching to these are such as the following : — (1) Delicacy of discrimination of Degree. The most marked of our emotional experiences consciously discriminated, but not with minuteness, — those that yield the finest sense of difference, — are of least value as pleasure ; and our intellectual states proper flourish upon fineness of discrimination. The most intellectual senses. Sight and Hearing, are the most delicate. (2) Memory, Eetentiveness, or persistence as images or ideas. The treatment of the Intellect will be an extensive commentary on this. (3) Plurality, or Complication. An unintellectual sensation has few distinctive points ; a highly intellectual sense, as sight, takes in, at the same instant, a large plurality of distinguishable impressions — the more the better. Hearing, in this respect, may not be on a par with sight, yet one can realise at the same moment many distinct tones from a variety of instruments. (4) Vivacity, Intensity, or Presentative Activity (Herbart). Other properties being the same, two impressions of sense may differ in the energy or intensity of the effect on the consciousness. An inscription may be intelligible, but feeble : it may be either in INTELLECTUAL CHARACTERS OF FEELING. 77 printer's type or in letters of fire, like ' God save the Queen ' on a birthday celebration. The starry heaven has many gradations of vivacity, the number of stars visible to the eye being nearly the same. So with Hearing and the Ideas of Sounds. Our consciousness reveals and measures this peculiarity. It shows itself in a very notable way when several different sensa- tions or images come together : the one that takes the lead and excludes the others is the strongest. The Intellectual properties of Discrimination (with Agree- ment) and Eetentiveness are generally influenced by the state of the Feelings at the time ; chiefly in the matter of Degree, irre- spective of Quality. To recur now to the problem of fixing a scale of Degree for the Feelings strictly so called. We have laid down as means to this end : (1) Conscious direct comparison ; (2) Conscious indirect comparison, by the neutralis- ing of opposites ; (3) the physical or objective indications both emotional and volitional, — which is greatly extended by the con- ventional signs of feeling, language being the principal ; (4) the impressing of the Intellect. The inter-relationship or mutual action of Feeling and Thought provides other criteria for judging each by the other. Indeed, the intellectual signs of feeling are numerous and far-reaching. (5) Intellectual associates with gradations of feeling. There are in our life-experience numerous situations and surroundings that become stamped in the memory in connexion with definite grades of pleasure and pain, elation and depression, and thereby serve to measure the intensity on any occasion by recalling the circumstances suited to that occasion. So, the direction given to the thoughts precisely estimates the state of the feelings. In high elation, the outlook, anticipations, and plans have a very special direction, not caused by a mere ordinary pitch of pleasure ; while the depths of depression are made known by the gloomy forebod- ings and the desperate resolves that rise up unbidden. Hamlet's depression was set forth by — Man delights not me ; no, nor woman neither. So, according to Young : — Health keeps an Atheist in the dark. 78 THE MUSCULAR FEELINGS. Our imaginatioas of Heaven and Hell are used for the same purpose as real situations. ' The seventh Heaven ' and ' the lowest Hell ' are the embodiment of the greatest conceivable extremes of happiness and misery. There is a degree of despair that drives to suicide, another that simply makes the idea of death welcome, a third that merely brings us to pronounce life not worth living. 9. The feelings connected wdth the moving organs may be classified thus : — (1) Feelings dependent on the organic condition of the muscles; as those arising from fatigue, rest, nutriment, hurts, diseases. A certain number of these the muscles have in common with the other tissues of the body ; others will be considered under the heading of Organic Sensibilitj'. The states that characterise muscle are to be traced in con- nexion with its normal exercise as the instrument of our movements or activity. There is a sub-division here, accord- ing as w^e look at the fact of energy passing outwards, or at the resulting stimulus imparted to the sensory or ingoing fibres of the muscles. Our Subjective Consciousness indicates a difference that we may possibly interpret as corresponding to the two physical situations. (2) Feelings connected with muscular action, including all the pleasures and pains of bodily exercise, together with the measure of our muscular expenditure when indifferent as regards pleasure and pain. The two modes are not mutually exclusive ; it is only a question which of the tw^o shall predo- minate in any one case. The same doubleness of aspect holds likewise in the Senses at large. I. Feelings of Muscular Exercise. These are the feelings proper to the muscles. The mode of consciousness arising under muscular exertion cannot be produced or imitated in connexion wath any other part of the system. 10. Feeling of Muscular Exercise generally. — According PHYSICAL SIDE OF MUSCULAE SENSIBILITY. 79 to the manner of the exertion, the feehngs differ considerably : a dead strain is different from movement, and distinct modes of consciousness attend quick and slow movements respectively. The most general and characteristic form of muscular exercise is exemplified in a dead strain, or else in great exertion with a moderate pace of movement. 11. To begin with the Physical side. The physical state of a muscle under contraction may be inferred from the details already given. The particles making up the muscular threads are approximated by an energetic attraction developed n\ the muscle, under the stimulus supplied by the nerves. An intense physical force is produced by a peculiar expenditure of the substance of the muscular mass ; and, in the production of this force, the tissue is affected, as it were, with a strong internal agitation. As the nerves supplied to the muscles are principally motor nerves, by which the muscular movements are stimulated from the brain and nerve centres, our safest assumption is, that the sensibility accompanying muscular movement coincides with the outgoing stream of nervous energy, and does not, as in the case of pure sensation, result from any influence passing inwards, by incarrying or sensitive nerves. It is known that sensitive filaments are distributed to the muscular tissue, along with the motor filaments ; and it is reasonable to suppose that by means of them the organic states of the muscle affect the mind. It does not follow that the characteristic feeling of exerted force should arise by an inward transmission through the sensitive filaments ; on the contrary, we are bound to presume that this is the concomitant of the outgoing current, by which the muscles are stimulated to act. No other hypothesis so well represents the total opposition of nature between states of energy exerted and states of passive stimulation. ' The reference to the Muscles opens up the much discussed question of the physical side of our subjective sensibility to pressure, strain, and active exertion in every form. This case is illustrative, in a way of its own, of the value to be attached to 80 THE MUSCULAE FEELINGS. the study of physical concomitance in mind. It so happens that, in this region, the subjective analysis is self-sufficing, that is, in- dependent of hints or confirmation from the physical side. It will probably be admitted by all the disputants on such a well- threshed question, that subjectively we can establish as distinguish- able modes of consciousness the following series of states of feel- ing : — Sense of energy expended, pleasure of muscular exercise, pain of fatigue, pleasure of repose, pains of morbid states, as cramp, not to speak of minuter variations of those leading modes of sensibility. Now, working upon the usual analogies of the senses, where we can generally assign to each important variety of sensation a local seat, there would be a propriety in assigning some distinct mode of stimulating muscle to each of the several classes now enumerated. One hypothesis connects the sense of energy with the outgoing motor current ; while the pleasures and pains of exercise and repose, which can be best viewed as passive sensation, would accompany the ingoing sensory current through the sensory fibres of muscle : to these might be added any known adjuncts of sensation from the peripheral parts involved in mus- cular action. There would be a certain cougruity with the sub- jective facts in this mode of assigning the concomitance ; yet its verification would not add to the evidence of our subjective analysis, and its overthrow would not impair the validity of that analysis. We cannot quote this instance as even particularly illustrating the use of a physical hypothesis in supplying sub- jective expression. We derive all the benefit of the physiological reference by using such objective terms as muscle, motion, action, rest, without committing ourselves to the concomitance of our feeling of energy with the outgoing current' Mind, vol. xvi., p. 11). But the physical accompaniments of muscular exertion pass beyond the muscles themselves. We know that active exercise indirectly affects all the organs of the body. The circulation of the blood is quickened generally, and is made to flow by preference to the muscular tissue, the brain being in this way often relieved from a morbid excess of blood. The lungs are stimulated to increased action. The elimi- nation of waste matter from the skin is promoted. There is EXPRESSION OR EMBODIMENT OF MUSCULAR FEELING. 81 a great increase of animal heat. Provided the waste of nutritive material caused by these various modes of increased action is duly supplied, the vital force of the system as a whole is raised by muscular exercise. So much for the corporeal seat of Origin of the sensi- bility in question. There is still another physical aspect, — namely, the Expression or Embodiment of the Feeling, which is not only the means of making known the state to others, but also an essential concomitant of its own exist- ence. By the very nature of the case, the feeling arising from great bodily exertion is liable to be wanting in Expression, properly so called. The organs are so completely employed in the exercise itself that they are not disposable as instru- ments of the expression of the feeling. The features of the face and the voice, which are by pre-eminence the organs of expression, are exerted chiefly in sympathy with the muscles engaged in the exercise (see Instinct, Primitive Combined Movements). Hence, as regards outward display, there is nothing to be remarked in connexion with muscular effort generally. It is only when the feeling happens to be pleasurable or the reverse, that any expression is shown ; and such expression is merely the attendant of the pleasure or the pain as such. 12. AYe pass now to the Mental side. In reviewing the characteristics of the mental accompaniment of nmscular action, viewed as Feeling, we will advert first to its Quality. Observation shows that this is pleasurable, indifferent, or painful, according to the condition of the system. The first outburst of muscular vigour in a healthy frame, after rest and nourishment, is highly pleasurable. The intensity of the pleasure gradually subsides into indifference ; and, if the exercise is prolonged beyond a certain time, pain ensues. In ordinary manual labour, there may be, at commencing in the morning and after meals, a certain amount of pleasure caused by the exercise, but it is probable that, during the greater part of a workman's day, the feeling of exertion is in 6 82 THE MUSCULAR FEELINGS. most cases indifferent. If we confine ourselves to the dis- charge of surplus energy in muscular exertion, there can be no doubt that this is a certain source of pleasure in the average of human beings, and doubtless also in the animal tribes. The fact is shown in the love of exercise for its own sake, or apart from the ends of productive industry and the preservation of health. In the case of active sports and amusements, there are additional sources of pleasurable ex- citement ; but the delight in the mere bodily exertion would still be reckoned one ingredient in the mixture, in fact must be considered as the essential groundwork of the whole. A part of the pleasure of exercise may perhaps be attri- buted to the increase of vital power generally ; and the question arises, may not the whole be due to the augmented force of the circulation, respirations, etc. ? It is certain that the rising to a higher condition as regards these important functions, is a source of pleasurable excitement. We may reasonably suppose, however, that the muscular system, which is the seat of so much unquestioned sensibility, should be capable of affording pleasure under favourable condi- tions ; and I think our consciousness attests the same fact. The agreeable feeling in the exercise of the muscular organs, when the body is strong and fresh, can be localised, or re- ferred to the muscles actually engaged. And it will be seen, as we proceed, that there are various facts connected with movement that are inexplicable, unless we suppose that the muscular tissue is of itself a seat of pleasurable, as it certainly is of painful, sensibility. In apparent rest, we are relaxing a number of muscles, while at the same time stretching others. We thus give birth to a mixed state of repose and exercise. The resulting pleasure may hence consist of rest from those muscles that have actually been fully drawn upon, and exertion of others that, being in abeyance, still possess their pristine freshness. As to the Degree of this pleasure, we must, of course, pro- nounce it variable according to circumstances. But taking a MEASURE OF DEGREE. 83 common case, as that of an average healthy human being, going through each day the amount of bodily exercise that the system can afford, we should have to admit that this is an appreciable constituent of our enjoyment. Doubtless, by contriving such a combination of exercises as to bring all the powerful muscles into full play, the pleasure could be in- creased considerably above the ordinary experience in this respect. The pleasure is not what would be called acute, or of great intensity ; its degree arises from the stimulation of a large mass of tissue. A measure of the degree of our pleasures is found, not merely in comparing one with another in consciousness, but also in observing the pains that they are respectively able to subdue. In this particular case, however, there is a tendency to subdue pain, not through the evolution of pleasure merely, but through some of the direct physical consequences of muscular movement, as well as by the objective attitude that accompanies muscular expenditure. The derivation of blood from the brain reduces the cerebral excitement, and with that the mental excitement, and so may operate in quench- ing painful irritation. In Sport, the muscular pleasure is almost overpowered by the more subtle excitements of sense and emotion. At the same time, that it is an important ingredient may be seen from the fact that the delight in active sports and exercises is found in connexion with a certain endowment of muscular vigour. Although this may be partly owing to the endurance necessary for the pleasure of sport, it probably also involves the pleasure of exercise itself. On the other hand, muscular pleasure is strictly confined to exuberant muscular energy, and fades with that. It has no tendency to supply an acute nervous stimulus of the pleasurable kind, such as may continue by a nervous tremor solely. It is, perhaps, the best example of the concurrence of pleasure with a nourished or efficient condition of the organ concerned. The third point in the description respects any Speciality in the case, serving still further to describe or characterise 84 THE MUSCULAR FEELINGS, the feeling in question. Now, as regards muscular exertion, there is a notable speciality, a radical difference in kind ; signified by such phrases as 'the sense of power,' ' the feeling of energy put forth,' ' the experience of force or resistance '. This is an ultimate phase of the human consciousness, and the most general and fundamental of all our conscious states. By this experience, we body forth to ourselves a notion of resistance, force or power, together with the great fact de- nominated an external world. In the sense of energy exerted, we are said to go out of self, or to constitute a something in vital contrast to all the rest of our mental experiences, — a not-me, as opposed to the me of passive sensibility and thought. With regard to the Volitional peculiarities of the pleasure of muscular exercise, there is not much to be remarked. As apleasm'e, it will work for its own perpetuation, increase, or renewal. According to the doctrine of spontaneous activity, the sense of pleasure would not be necessary for our passing into an active state in the first instance ; but would simply operate to maintain the activity, and, by help of intelligent forethought, to keep the system in a high condition of fitness for the periodical effusion of energy. The workings of muscular feeling, as the pleasure of exercise on the one hand and the pains of fatigue on the other, illustrate the law of the Will in its most simple and primordial form. While conscious of the flush of energy, we go on expending our surplus force and keep the organs iu action so long as that consciousness continues. When the state of pleasure dies away, so does the activity generated on its account ; although other motives coming into play may continue it. When the action is maintained to the point of commencing fatigue, it ceases of its own accord, unless a still more powerful motive is present. See Instiyict (Germ of Volition). The distinctively Intellectual properties of the muscular feehngs will have to be referred to as the sources of highly important perceptions. But, before considering these, we PERSISTENCE IN IDEA. 85 should notice an intellectual aspect or property belonging to these feelings, in their strict character of feelings, or as pleasures and pains, — namely, the fact of their greater or less persistence in the memory, so as to constitute ideal pleasures or pains, and, in that capacity, to stimulate the will in pursuit or in avoidance. A pleasure may be very intense in the actual, but feeble in the ideal, or in the memory. Such a pleasure would not in absence prompt the will to energetic efforts for realising it. Now, the pleasures of muscular exercise do not take a high place among persisting, remembered, or ideal pleasures. They are, perhaps, not at the bottom of the scale in this respect ; but they are not much higher than the least intellectual of the sensations, — as, for example, those of Digestion. x-is regards active amusements, sports, and occupations, which readily become fixed objects of passionate pursuit, the intellectual persistence or memory involved attaches more to the accompanying states of sense and emotion that nnpart to them their character. But the truly important intellectual aspect of muscular feeling is something quite different from any ideal pleasures and pains of exercise. It regards the discriminating and identifying of degrees and modes of the characteristic con- sciousness of expended energy ; an experience corresponding with the great facts of the object world, — resistance, force, power, velocity, space, time, etc. In these perceptions, there may be a neutrality as regards pleasure or pain. We have already assumed that, between the pleasure of exercise and the pain of fatigue, there is an intermediate state where there is still the characteristic feeling of energy expended. In this state, we usually cease to attend to the feeling, as feeling proper : we are occupied with the purely intellectual functions of discrimination and agree- ment ; we think of the present expenditure as greater or less than some other expenditure, or as agreeing with some previously known instances. This is to be intellectually engrossed ; and, under such an engrossment in the case of muscular exercise, we assume the object attitude ; w^e are not 86 THE MUSCULAR FEELINGS. self-conscious, but are engaged in knowing certain purely object facts, called force, extension, etc. Even if muscular exertion were attended with the plea- sures of exercise or the pains of fatigue, yet if, from any circumstance, we were led to consider intently the degree or amount of the expenditure, as in aiming a stroke at golf, we should at that moment be entirely unconscious of the pleasure or the pain of the situation ; the intellectual attitude (in this case the object attitude) is incompatible for the in- stant with the subject experience proper, of which pleasure and pain are characteristic modes. Even in the highest zest of muscular enjoyment, the feeling of pleasure is inter- mittent : it is eclipsed in the act of putting forth energy and of considering and comparing its amount : and reap- pears at the end of the stroke, or during the suspense of our attention to the act itself. In this subtle transition or con- trast is laid the groundwork of the fundamental opposition of subject and object — mind and matter. A great deal hangs upon the grand distinction between Siib- ject and Object states, which pervades the whole range of our mental workings. The case now supposed affords one illustra- tion ; many others will arise in the course of the exposition, and an opportunity will be found for resuming the whole in compre- hensive language. 13. Having thus endeavoured to present a delineation of the first and simplest variety of muscular consciousness under exertion, we shall now cite a few examples of this form of the feeling. The supporting of a weight on the back, head, or chest, or by the arms, is a common example of Dead Strain or ten- sion. The most interesting form of it is the support of the body's own weight, which yields a perpetual feeling of the muscular kind varying with the attitudes. The feeling is least when we lie at full length in bed, and greatest in the erect posture. Sometimes the weight is oppressive to us, and gives the sensation of fatigue ; in a more fresh condi- SLOW MOVEMENTS. 87 tion of the muscles, it makes one item of our pleasurable consciousness. The fatigue of standing erect for a length of time is, perhaps, one of the commonest cases of muscular exhaustion. The pleasure of standing up after a lengthened repose gives an opposite feeling. This case of great muscular tension, without movement, presents itself under a variety of forms, — in the routine of mechanical operations, and in many other ways. In holding on as a drag, in offering or encountering resistance of any sort, in compressing, squeezing, clenching, wrestling, the situation is exemplified. A certain amount of movement may be permitted without essentially departing from the case of dead tension, — as in dragging a vehicle, and in efforts of slow traction generally. 14. Muscular tension ending in Movement is a new situation physically. In this case, there must be a gradually increasing contraction, and not a mere expenditure of power at one fixed position. Each muscle has to pass through a course of contraction ; begin- ning, it may be, at the extreme state of relaxation, and passing on, sometimes slowly, and at other times rapidly, to the most shortened and contracted condition. The sensibility developed during this process is greater in degree than, and even somewhat different in kind from, that now discussed. As a general rule, the feeling is more intense under movement than under exertion without movement. The successive contraction of the muscle would seem capable of originating a more vivid stimulus than the fixed contraction. We even find that in different degrees of rapidity the character of the feeling changes, which requires us to make a division of movements into several kinds. 15. Let us first advert to what we may term, by compari- son, sloiv movements. By these I understand such as a loitering, sauntering walk, an indolent style of doing things, a solemn gesture, a drawling speech, whatever is set down as leisurely, deliberate, dawdling. The emotion arising from this kind of movement is far greater than an equal effort of dead tension would produce. Indeed, we may say that this is an 88 THE MUSCULAR FEELINGS. extremely voluminous and copious state of feeling ; being both abundant and strong, although deficient in the element that we recognise as the sense of energy, or of expended force, — in fact, approaching more to the class of passive feelings. We may derive the greatest amount of pleasurable sensibility at the least cost of exertion, through the means of well-con- certed slow movements. In their case, it seems probable that, together with the sense of expended energy, there is also present the proper sensibility of the muscular tissue, awakened through the medium of the sensitive nerves. The resemblance of the state to the feeling of muscular re- pose (which probably makes an element in the voluminous sensation of approacliing sleep) favours this view. The sense of expended energy is small, — -in fact, almost wanting". But we must not overlook another circumstance, accounting for a copious sensibility under a small expenditure of force. When the energies of the system are strongly directed into the current of muscular activity, they are less available for the support of sensibility or feeling : the putting forth of energy in bodily movements is a diversion of the forces from the seats of passive sensibility, and is a well-known remedy for too great mental excitement. Hence, inversely, the small- ness of the active expenditure permits a larger manifestation of sensibility or feeling. The relationship of the feeling in question to muscular repose and approaching sleep, is seen in the tendency of slow movements to induce these states. They are pre-eminently soothing in their nature, and when the system has contracted a morbid restlessness, they can gradually restore it to the healthy condition. Movement generally — that is, in all its various manifestations — has superinduced upon it aesthetic developments or aggregates. Hence, we cannot attribute to pure muscularity the many power- ful influences that accompany the various kinds. After a bustling day, tranquillity is attained by the mere sympathy of measured movements, as in music and the conversation of persons of sedate elocution. There is a close intimacy between the feelings of QUICK MOVEMENTS. 89 slow movement and certain powerful emotions, as awe, solemnity, veneration, and others of tlie class of mingled tenderness and fear, entering into the religious sentiment. Accordingly, the funeral pace, the slow enunciation of devotional exercises, the solemn tones of organ music, are chosen as appropriate to the feelings that they accompany. All this still further supports the position, that the feeling under consideration is not one of active energy, but the opposite. For, all those sentiments are the re- sponse of man's powerlessness and dependence, and are developed according as the sense of his own energy is low. 16. There is every reason to believe that movements gradually increasing or gradualUj diminishing are more pro- ductive of pleasm-able emotion, than such as are of a uniform character. Indeed, a uniform movement is altogether of artificial acquirement. The natural swing of the limbs tends to get quicker and quicker up to the full stretch, and to die away again gradually. There would appear to be a special sensibility connected w^ith the acceleration or steady diminu- tion of movement. The gradual dying away of a motion is pleasurable and graceful in every sort of activity — in gesture, in the dance, in speech, in vision. The ' dying fall ' in sound is an illustration of the same fact. It also goes to make the beauty of curved lines. Something of this augmented sensibility may be a consequence of the great law of Relativity, or the necessity of change to our being mentally affected. A gradual acceleration or diminution of any agent that wakens sensibility is the surest antidote of monotony, — in other words, the condition most favourable to con- sciousness. But, as just remarked, the full rendering of these phenomena demands a variety of aesthetic considerations, of which the principal seems to be the connexion of curved lines with the human form, and the various emotions attaching to personality. 17. We pass next to the consideration of qtdcJi move- ments. These differ considerably in feeling both from dead exertion and from slow motion. Although there may seem to be a common muscular sensibility underlying, there 90 THE MUSCULAE FEELINGS. is a well-marked specific nature. One accompaniment of the quickness is the increased excitement of the nerves ; an increase totally distinct from the addition of energy- expended to heighten an effort of dead resistance. Mere rapidity of movement has a specific influence in exciting the nerves and nerve centres to a greater activity of their own ; in short, it belongs to the class of nervous stimulants. The stimulation would appear to be all the greater when the organs have full swing, and, consequently, demand little ex- penditure of energy. For inducing an unwonted degree of excitement generally, for inflaming the animal spirits, and bringing on various manifestations and exaggerated efforts, quick movement is an available instrumentality. We may compare it, in this respect, with acute pains, not severe enough to crush the energies. Eapid motions are a species of mechanical intoxication. Any one organ, however small, made to move quickly, imparts its pace to all the other moving organs. In a rapid walk, still more in a run, not too violent, the mental tone is excited, the gesticulations and the speech are quickened, the features betray an unusual tension. Examples of this class of motions and feelings are suffi- ciently abundant. They are expressly sought to give hilarity and excitement to human life. The chase, the dance, the vehemence of oratory and gesture, the stirring spectacle, are prized for their stimulating character, as well as for their proper sensations. In the ecstatic worship of antiquity, — in the rites of Bacchus and Demeter, — a peculiar frenzy over- took the worshippers, yielding an enjoyment of the most intense and violent character, and, in its expression, mad and furious. This state is often brought on among the Orientals of the present day; and in a similar manner, — namely, by rapid dancing and music, under the exhilaration of a multitude. Thus, then. Dead Eesistance is a source of pleasure in a healthy system, a derivative of morbid excitement from the brain, and the origin of our most general and fundamental PASSIVE MOVEMENTS. 91 sensibility, constituting the consciousness of the object or external world. Slow Movements are allied to the passive pleasures, and may affect us more through the sensitive than through the motor nerves of the muscles. Quick Move- ments affect us less as movement than as stimulating the nerves to increased action ; the consequence being a higher mental tone for feeling, for volition, and for thought. 18. We may, next, advert to what are called ^ass/ye (but more properly compelled) movements. Eiding in a vehicle is the commonest instance. One of the pleasures of human life is to be driven along at a moderate speed, in an easy carriage. The analysis of this situation shows a certain amount of muscular feeling akin to slow motion, with other ingredients more expressly connected with the sense of sight. The muscular element can be isolated in one's ex- perience of driving in the dark. When we examine it so, we can trace in it a considerable mass of muscular sensibility at a low expenditure of fatiguing exertion. Even a certain amount of jolting is not disagreeable, although in greater amount it rises to muscular pain — the pain of violence of shock, — which it is not difficult to account for. Hence the luxury of easy motion, as attained by sprnigs and cushions in our costly vehicles. The shifting of scene before the eye is a sensuous element accompanying all our modes of locomotion in the light of day. It belongs to the great fundamental law of change of impression, as removing the oppressive influence of sameness or monotony. The most interesting point for remark is the gi-eat influence of pace in determining the gratification imparted in the course of the operation. A slow movement is not effective in this part of the case ; it, seemingly, falls short of the expectations that we are liable to form, either from the failure to attain the end of a jour- ney, or from the insufficient regalement of the mind in passing from one object to another. As a matter of course, the intrinsic interest of the scene is a large element in the situation : it de- termines us to retain the attention at individual points, instead of hurrying along. 92' THE MUSCULAE FEELINGS. That there is a purely physical result connected with the passing of scenes and objects before the eyes is shown by the illustrative extreme of the dizziness produced in railway travel- ling when the view is confined to near objects, as when shut in between sloping banks. Such an extreme points to a middle position where there is no such effect, but where, on the other hand, there is a really pleasurable sensation, even if found to be exhausting when long persisted in. This phenomenon would seem to pass entirely out of the muscular department and to connect itself with optical sensibilities of a distinct class. In horse exercise, there is a large amount of the in- gredient of activity. The rider is saved a part of the exhaustion caused in w-alking, and has yet exercise enough for the stimulus of the bodily functions, and for muscular pleasures, including also the shifting of the scene. The rocking-chair, introduced by the Americans, who seem specially attentive to the luxuries of muscular sen- sibility, is another mode of gaining pleasure from movement. In former times, furniture was adapted to the pleasures of repose solely, but now the boy's rocking-horse has its representative among the appurtenances of grown men. On the whole, it is apparent that a large fraction of physical enjoyment flows out of the moving apparatus and muscular tissue of the body. By ingeniously varying the modes of it, this enjoyment is increased still further. The pleasure comes incidentally to manual labour, when moderate ill amount and alternated with due sustenance and repose, and is a gi'eat element of field sports and active diversions of every kind : it is a part of the pleasures of locomotion, and contributes a certain ingredient in gymna.stic exercises and athletic displays. II. The Intellectual Aspect of Muscular Feelings. 19. In alluding to the strictly Intellectual properties of the feeling of expended muscular energy, we had to advert to that mode, neutral as regards pleasure and pain, wherein DISCRIMINATION OF MUSCULAR ENERGY. 93 we are occupied with tiie properties of the object world, as resistance, force, etc. This grand function of our muscular sensibility is grounded, in the first instance, upon our discrimination of differences in degree. Holding a weight of four pounds in the hand, we have a distinct change of consciousness on adding another pomid. As Pleasure or Pain, this conscious- ness may be wholly insignificant ; as a medium of our knowledge, it is all-important. Three modes of muscular change accompanied with change of consciousness may be assigned. The first is the simple amount of exertion, or of expended force. This may be regarded as the fundamental experience. The second respects the continuance of the exertion, and applies alike to dead strain and to movement. The third is a mode of movement solely ; it is the rapidity of the muscles' contrac- tion, which corresponds to the quickness of movement in the organ. In distinguishing the qualities of external things, and in attaining permanent notions of the world, all these discriminations are brought into play. '20. First, with respect to degrees of Exertion, or of Expended Force. This is the sense of Eesistance, the basis of our conception of Body, and our measure of Force, Inertia, Momentum, or the Mechanical property of matter. We have a certain feeling when we exert our muscular energy in causing movement, or in encountering resistance. We have a certain degree of consciousness for some one degree of exertion ; when the exertion increases, so does the consciousness. If a porter places on his back a load of one hundredweight, he has a peculiar and distinct muscular feeling associated with it ; if thirty pounds be added, he has a sense of the addition in the increased expenditure of force ; if thirty pounds be removed, he has a feehng of diminished expenditure. In short, there is a certain discrimination of degrees of muscular energy, which serves us as a means of discriminating the resistances that we encounter. Hence, we are able to say that one body resists 94 THE MUSCULAR FEELINGS. more than another — possesses in greater degree the quahty that, according to circumstances, we call force, momentum, inertia, weight, or power. AVhen we encounter two forces m succession, as in a wrestling match or a dead push, we distinguish the greater from the less. 21. Among the various occasions where the sense of graduated resistance comes into play, mention may be made, first, of the momentum or force of moving bodies. Where we have to check or resist something in motion, our sensi- bility to expended exertion leaves with us an impression cor- responding to the momentum of the moving mass. If we were immediately after to repeat the act with another moving object, heavier or swifter than the first, we should have a sense of increased effort, which would mark our estimate of the difference of the two forces. Supposing the impressions thus made to be gifted with a certain kind of perman- ence, so that they could be revived at an after time to be compared with some new case of checking a moving body, we should then be able to say which of the three was greatest and which least, and, in this way, we should have a scale of sensibilities corresponding to the three different degrees of embodied force. Such exercises as digging the ground, rowing a boat, or dragging a heavy vehicle, do not essentially depart from the case of the dead strain ; and, in all these instances, there is an estimate of expended force. Every carriage horse knows the difference of draught between one carriage and another, be- tween rough and smooth ground, and between up hill and down hill. This difference the animal comes to associate with the carriage, or with the sight of the road, and, in con- sequence, manifests preferences whenever there is an oppor- tunity ; choosing a level instead of a rising road, or the smooth side rather than the rough. The appreciation of weight comes under the dead strain. "We remark a difference between half an ounce and an ounce, or betw^een five pounds and six pounds, when we try first the one weight and then the other. The generality of people can WEIGHT. 95 appreciate far nicer differences than these, A sensitive hand would feel a small fraction of an ounce added to a pound. In this respect, there would appear to be wide constitutional differences, and also differences resulting from practice, among different individuals. We are all sensitive to some extent, but there is for each person a degree of minuteness of addition or subtraction that ceases to be felt ; this is the limit of sensibility, or the measure of delicacy in the individual case. There are two modes of estimating weight, — the relative and the so-called absolute. By relative weights, we may un- derstand two or more present weights compared together ; as when, from among a heap of stones, we pick out what we deem the heaviest. Absolute weight implies a permanent standard, and a permanent impression of that standard. When I lift a weight and pronounce it to be seven pounds, I make a comparison between the present feeling and the impression acquired by handling the standard weight of seven pounds, or things known to be equivalent thereto. This absolute comparison, therefore, implies the enduring and recoverable sensibility to impressions of resistance, which is also a fact of the human constitution. We can acquire a permanent sense of any one given weight or degree of resistance, so as to be able at all times to compare it with whatever weight may be presented. A receiver of posted letters contracts an engrained sensibility to an ounce, and can say of any letter put into his hand whether it produces a sensibility equal to or under the standard. This, too, is a result pre- eminently intellectual in its nature : the process of acqui- sition that brings it about ranks as a fundamental property of our intelligence. The sensibilities that can assume this permanent character, so as to be used in fixing weight values, without the presence of their original cause, are truly intel- lectual sensibilities. The sensitiveness to relative weight, or to things actually compared together, may not imply great sensitiveness to absolute weight, which involves a greater or less degree of retentiveness or memory. 96 THE MUSCULAR FEELINGS. Although the use of the balance supereedes, to a very great extent, the appeal to the sensibility to weight residing in the muscular system, there are, of course, occasions where this sensibility can display its acuteness. In many manual operations, weight is often estimated without the aid of the balance. In the throwing of a missile to reach a mark, an estimate of weight must enter into the computation of the force expended. In appreciating the cohesiveness of tenacious bodies — the thickness of a dough, or the toughness of a clay, — the same sense of resistance comes into operation. In like manner, the elasticity of elastic substances — the strength of a spring, the rebound of a cushion — can be discriminated with more or less nicety. 22. The second mode of muscular discrimination respects the Continuance of it. A dead strain of unvarying amount being supposed, we are differently affected according to its duration. If we make a push lasting a quarter of a minute, and, after an interval, renew it for half a minute, there is a difference in the consciousness of the two efforts. The endurance implies an increased expenditure of power in a particular mode, and we are distinctly aware of such an increase. We know, also, that it is not the same as an increase in the intensity of the strain. The two modes of increase are not only discriminated as regards degree, they are also felt to be different modes. The one is our feeling and measure of Resistance or Force, the other becomes ultimately one of our modes of estimating variations of Time. It is a circumstance connected with impressions on the senses generally, that they should be differently felt according as they are of longer or shorter duration. The same is true of the higher emotions. Moreover, the increase of expenditure in the form of increased stimulus must be distinguished by us from the increase due to the greater continuance of the same stimulus. The estimate of continuance attaches no less to Move- ment. In lifting a weight successively, one foot, two feet. PACE OF MOVEMENTS. 97 three feet, we have a sense of inequality of expenditure ; while not confounding the exertion of lifting the same weight three feet with raising a triple weight one foot. Thus, the continuance of movement expresses more than the continuance of a dead strain. It is the sweep of the organ through space; and finally connects itself, therefore, with the measure of space or extension. For although, in our per- ception of the extended, we need to combine sensations of the senses with sweep of movement, yet the most essential part of the cognition is furnished by our feelings of move- ment. From the working of a process, to be afterwards adverted to, we learn the difference between the coexisting and the successive, between Space and Time ; at which stage, muscular sweep, or the continuance of muscular movement, is a means of discriminating the differences of extended matter, or Space. It teaches us first the degree of linear extension, as measured by the sweep of a limb or other organ. A greater linear magnitude is a greater con- tinuance of a simple muscular movement. The discrimination of length in any one direction ob- viously includes extension in every direction. AVhether it be the length, breadth, or height of an object, the perception has precisely the same character. Hence, superficial and solid dimensions, the size or magnitude of a solid mass, come to be felt through the same fundamental sensibility to expended muscular force. All this will be understood more fully at an after stage, when we shall have to consider muscularit}- in connexion with the senses of Touch and Sight. 23. Under the foregoing head, we supposed the case of steady or uniform movement, and called attention to the power of discriminating the greater or less continuance of it. But movements may vary in their Speed ; and it is now to be considered how the mind is aff'ected when the speed is increased or diminished. This is also a mode of expending additional power ; and it is not possible for us to increase our expended energy without being conscious of the fact. The only doubt that might arise is, as to our being 7 98 THE MUSCULAR FEELINGS. able to distinguish all the various modes of increase — in- crease in the dead strain at any one instant, increase in the duration of the strain, increase in the duration of a move- ment, increase in the velocity of the movement, — so as to be av^are which mode of increase or diminution we are under for the time. If we confounded all these modes of increase under a common impression of intensified energy, our mus- cular discrimination would be wholly inadequate to the per- ception of the external world ; and, in particular, our ability to estimate extension would have to be referred to some other part of our constitution. But it is quite certain that we are differently affected under these various situations. Owe con- sciousness is not the same, when we augment the energy of a dead resistance, as when we protract the time of that re- sistance ; nor is it the same when we prolong the duration of a uniform movement, as when we augment its speed. We are aware, when we accelerate our pace, not merely that more power is going out of us, but that such power is in one especial mode, which we distinguish from other special modes. This being assumed, we are cognisant of degree in the rapidity of our movements, and so possess the power of estimating another great property of moving bodies, the velocity of their motions. The measure is, perhaps, first taken on our own movements, and thence extended to other mov- ing things that we encounter. When we follow a moving object with the hand, or with the eye, or keep pace with it, its velocity is transferred to ourselves, and estimated accordingly. The feeling of the rapidity of muscular contraction has a further office. It is an additional means of measuring Ex- tension. An increase of velocity in the same time corresponds to an increase of range of extension, no less than the same velocity continued for a greater time. Extent of Space thus connects itself with two separate discriminations,— Continu- ance, and Velocity, of movement. The distinct feelings from the various forms of muscular exercise, as formerly explained, whereby we are differently STATE OF A MUSCLE'S CONTEACTION. 99 affected according as movement is quick or slow, are thus of great intellectual importance, as enabling us to be character- istically impressed by each varying degree of velocity. The soothing tendency of the slow motions, and the exciting effect of the comparatively rapid motions, are also instrumental in enabling us to discriminate degrees of velocity directly, and of space indirectly.* * A fourth vai'iety of muscular discrimination may be pointed out as in constant use, — namely, the sense of the amount of contraction of a muscle, and of the position of the limb in consequence. We are usually aware, not merely that we are putting forth a force of a certain degree and continuance, but that we are operating either at the beginning of the muscle's contraction, so to speak, or at some advanced stage of it. This determines, of course, the attitude or position of the part moved. We know, in exerting the arm in the dark, whether it is extended or bent, and whether it is thrown before or behind. We know, in grasping anything in the hand, whether the hand is very much stretched, or very much closed ; and we can judge of the different degrees of contraction determining intermediate positions. By this sensibility we are able, after experience, to estimate the magni- tudes of bodies without moving the arm or the hand, or other organ. By the mere stretching of the arms, without attending to the movement implied in that stretch, we measure in our mind the length of an object or of an interval. By the dead span of the fingers and thumb, we can estimate any length that is within the scope of the parts. It is usual to describe this particular discrimination as a sense of the state of the muscle's contraction, and to regard it as the primary or typical form of the muscular sense. Now, the discrimination must no doubt be an original fact — one cannot see how it could be acquired ; but the meaning given to it, the interpretation of the position of the limb, and of the magnitudes embraced between two outstretched parts, is wholly acquired. We must learn by ex- perience what movements correspond to the transition from one mode of con- traction to the other ; extension must be measured, first, by movement. A definite fixed position of the two arms, of the two legs, of the jaws, of the lips, or of the fingers and thumb, comes to represent a series of movements, and the corresponding estimate of space passed over by movement. Witli one hand resting upon the side of a box, and the other resting upon the top, we can tell the inclination of the two sides, without movement ; our experi- ence has made the feeling of certain combined dead tensions a symbol of a series of movements in different directions. Besides, if we would have an accurate appreciation of the amount of the contraction, we may still, in many cases, have to repeat the actual movements. The importance of this mode of discrimination is perhaps best seen in the eyes. It enters into the explanation of the binocular feeling of solidity. I have not inserted this feeling in the text among the fundamental dis- criminations of muscle, because it seems bound up with our sensibility to 100 THE MUSCULAR FEELINGS. We have thus gone over the two great classes of muscular feelings enumerated at the outset of the chapter.* This fundamental sensibility of our nature will come up again in a variety of connexions ; and much has still to be said in order fully to explain the growth of the perceptions of Externality, Force, Space, and Time. movement as there given. If, on the other hand, I were to assume the sense of the state of contraction as the primary feeling, the sense of movement would follow ; since movement implies that the muscle passes through a series of states of contraction, and the conscious sequence of these states would be the mental fact of movement. It is possible that the feeling of movement may consist in the primary feeling of expended energy (given in its purity in dead resistance), modified by a muscular sensibility arising in the change from one stage of contraction to another. But, be this as it may, I think it enough to assume as distinct and fundamental the three modes of muscular discrimination discussed in the text. * Sir William Hamilton, in liis Dissertations on Reid, p. 864, has drawn a distinction between what he calls ' the locomotive faculty ' and the muscular sense, maintaining that the feeling of resistance, energy, power, is due to the first and not to the second. By this locomotive faculty he means the feeling of volitional effort, or of the amount of force given forth in a voluntary action ; while he reduces the application of the term ' muscular sense ' to the passive feeling that he supposes us to have of the state of tension of the muscle. His words are : ' It is impossible that the state of muscular feeling can enable us to be immediately cognisant of the existence and degree of a re- sisting force. On the contrary, supposing all muscular feeling abolished, the power of moving the muscles at will remaining, I hold that the consciousness of the mental motive energy, and of the gx-eater or less intensity of such energy requisite, in different circumstances, to accomplish our intention, would of itself enable us always to perceive the fact, and in some degree to measure the amormt, of any resistance to our voluntary movement ; howbeit the concomitance of certain feelings with the different states of muscular tension, renders this cognition not only easier, but, in fact, obtrudes it on our attention.' The sense of expended energy I take to be the great characteristic of the muscular consciousness, distinguishing it from every mode of passive sensa- tion. By the discriminative feeling that we possess of the degree and con- tinuance of this energy, we recognise the difference between a gi-eater and a less stretch of muscular tension, and this appears to be the primary sensibility operating in the case. The other sensibilities of muscle, derived through the sensitive fibres, may aid us in the import£,nt discriminations between the different modes of increased energy above specified. I may here express the obligations we are under to Sir William Hamilton for his historical sketch of the doctrine of the ^Muscular Sense, contained in the same note ; which is not the least valuable and interesting of his many contributions to the history of mental science. 'T / CHAPTEK II. SENSATION. BY Sensations, in the strict meaning, we understand the mental impressions, feeHngs, or states of conscious- iiess, following on the action of external things on some part of the bodv, called on that account sensitive. Such are the feelings caused by tastes, smells, sounds, or sights. These are the influences said to be external to the mental organisa- tion ; they are distinguished from influences originating within, as, for example, spontaneous activity (the case we have already considered), the remembrance of the past, or the anticipation of the future. The Sensations are classified according to the bodily organs concerned in their production ; hence the division into five senses. But, along with distinctness of organ, we have distinctness in the outward objects, and, also, in the inward consciousness. Thus, objects of sight are different from objects of smell ; or, rather, we should say, that the properties and the agency causing vision are different from the properties causing smell, taste, or hearing. The difference of the mental feeling or consciousness in the different senses is strongly marked, being a more characteristic and generic difference than obtains among the sensations of any one sense. We never confound a feeling of sight with a feeling of sound, a touch with a smell. Leaving out of account pleasure and pain, these effects have the highest degree of distinctness that human feelings can possess. The discrimination of them is sure and perfect, although we sometimes try to assimilate them. 102 SENSATION. We are usually said to have five Senses : Sight by the eye, Hearing by the ear, Touch by the skin, Smell by the nose, Taste by the mouth. In addition to these, physiologists have distinguished a sixth sense, of a more vague descrip- tion, by the title of common or general sensibility, — as will be seen in the following extract from Messrs. Todd and Bowman. ' Under the name of common or general sensibility may. be included a variety of internal sensations, ministering for the most part to the organic functions and to the conservation of the body. Most parts of the frame have their several feelings of comfort and pleasure, of discomfort and pain. In many of the more deeplv seated organs, no strong sensation is ever excited, except in the form of pain, as a warning of an unnatural condition. The internal sensations of warmth and cbillness, of hunger, thirst, and their opposites, of nausea, of repletion of the alimentary, and genito-urinary organs, and of the relief succeeding their evacuation, of the privation of air, etc., with the bodily feelings attending strongly excited passions and emotions, may be men- tioned among the principal varieties of common sensations.' ■ In this enumeration, we can see several distinct groups of feelings, and can refer them to distinct bodily organs. Hunger, thirst, their opposites, nausea, repletion, and evacuation of the alimentar}- tube, are all associated with the digestive system. They might, therefore, be termed the digestive sensations. The privation of air causes a feeling whose seat is the lungs, and is one kind of sensibility associated with respiration. The sensations of warmth and chillness connect themselves with the skin, with the lungs, and with the organic processes in general. The genito- urinary organs have a class of feelings so special and peculiar, that they had better not be included under common sensibility. ' Looking at the important groups of feelings here indi- cated, important at least as regards human happiness and misery, considering, also, that they are but a few examples chosen from a very wide field, I consider it expedient to I THE FIVE SENSES NOT EXHAUSTIVE. 103 describe them in systematic detail. It is the business of a work hke the present to review the entire range of human sensibiht}', in so far as this can be reduced to genera] or comprehensive heads ; and the question is, Where ought these Organic feehngs to be brought in? I know of no better arrangement than to include them among the Sensa- tions. The only objection is the want of outward objects connected with them in every case. The feelings of comfort or discomfort arising from the circulation, healthy or otherwise, are not sensations in the full meaning of the term ; they have no distinct external causes, like the pleasures of sound, or the revulsion of a bitter taste. But the reply to this objection is, first, that in most cases, if not in all, an external object can be assigned as the stimulus of the feeling : for example, in the digestive feelings, the contact of -the food with the surface of the alimentary canal is the specific cause or object of the feeling ; so, the respiratory feelings may be viewed as sensations having the air for their outward object or antecedent. And, next, with reference to the cases .where feeling cannot be associated with an external contact, as in the acute pains of diseased parts, we maj^ plead the strong analogy in other respects between such feelings and proper sensations. In all else, except the existence of an outward stimulus, the identity is complete. The seat of the feeling is a sensitive mass, which can be affected by irritants external to it, and which yields nearly the same effects in the case of a purely internal stimulus. So much is this the fact, that we are constantly comparing our inward feelings to proper sensations ; we talk of being oppressed, as with a heavy burden, of being cut, or torn, or crushed, or burned, under acute internal sensibilit}'. Moved by such considerations, I class these feelings with sensations, and place them first in the order of the Senses, under the title of Organic feelings, or Sensations of Organic Life. In the Senses, as thus made up, it is useful to remark a division into two groups, according to their importance in the 104 SENSATION IN GENERAL. operations of the Intellect. If we examine the Sensations of Organic Life, Taste, and Smell, we shall find that as re- gards pleasm-e and pain,— that is to say, in the point of view of Feelmg or Emotion,— they are of great consequence ; but that as regards the permanent forms and imagery employed in the processes of the Intellect they contribute comparatively little. This last function is far more served by Touch, Hearing, and Sight, w^hich may, therefore, be called the Intellectual Senses by pre-eminence ; they being, however, not thereby prevented from serving the other function also, or from entering into the pleasures and pains of our emo- tional life. Preliminary Eemarks upon Sensation in General. The following topics belong to the consideration of Sen- sation at large, and may be adverted to at the commence- ment, while they will be more specially elucidated as the exposition proceeds. (1) While sensation is not improperly regarded as the beginning of conscious life, both intellectual and emotional, and as the foundation of our knowledge, both of the world and of ourselves, and is thus in contrt^st with Thought as a later and complex product, this must be held subject to the quahfication that the ordinary sensations of everyday life have lost their primitive character, and no longer possess the simplicity and purity of what might be called their original state. They continue to have one feature that keeps them distinct from the thought-processes, — namely, they owe their being to actual contact with the outside world, while Memory, for example, is independent of such origin. But the conscious result of a sensation in mature hfe, while con- taining an element of freshness and vividness that cannot be given in other ways, is a cumulation of present stimulus and previous impressions without number of the same effect. Practically, it is this aggregate of past and present that we call a sensation. We have not, usually, to take account of SENSATION AN AGGREGATE. 105 the circumstance that only a very minute portion of the conscious state arising is due to the present stimulus. The circumstance that makes the reference important is, that the actuality of the present shock is the necessary occasion of evoking in a vivid form the total aggregate. We may have tasted sugar thousands of times, and yet the pure memory part of the accumulated impression revived as memory is feeble indeed compared with the same during the incidence of a new or actual sensation. (2) Sensation is pre-eminently conditioned by the great law of Relativity, of which it furnishes characteristic ex- amples, showing both the range and the limitations of the law. (3) Sensations are said to vary in Degree or amount. Here, however, we must begin by distinguishing between their In- tellectual and their Emotional character. As intellectual elements, their main character is Discrimination ; the more discriminative they are, the more intellectual they are. This is not incompatible with another peculiarity called Vividness, whose meaning and criterion is the hold they take of the attention, so as to exclude or submerge rival impres- sions. It is still an element of Intellect, properly so called. Contrasted with this class of effects is the properly Emotional aspect, or the aspect of Pleasure and Pain. It is to this aspect that intensity has a more especial application and importance ; it determines the great fact of our being, as expressed by many well-known designations of enjoyment and suffering, and as making up the motive to our activity. In connexion with Degree, a law has been propounded connecting strength of stimulus with conscious intensity in the result. It is noticed that, whilp a certain strength of stimulus is followed by a certain strength of feeling, an addition to the stimulus, say doubling it, does not make the same addition to the sensation regarded as a conscious state ; we must go on increasing and increasing the one in a much higher ratio in order to get a steady increase of the other. As propounded by Fechner, this law was directed upon the 106 SENSATION IN GEXEEAL. purely intellectual property of sensation, — namely, discrimi- nation ; he did not attempt to verify it upon emotional states, as, for example, pure pleasure. Notoriously, something of the same kind would apply in this case also ; but its for- mula would probably not assume anything of the nature of numerical statement, nor would it be specially connected with sense pleasure in particular. Each one of the senses in detail has to be looked upon in the twofold aspect now described ; that is to say, as furnish- ing both intellectual and emotional products — appealing at one time to the Intellect and at another time to the Feelings. Their exhaustive description includes both elements. Even in the more strictlv emotional forms, discrimination is far from wanting, — as will be seen in the course of the enu- meration. In defining the Sensations, we put forward the three constituents or properties of Object, Organ, and resulting Feeling. For the Five Senses, these are well marked and distinct. For the group of Organic Sensations, there is less of distinct separation, as will be seen presently. Under Sensation, we have to anticipate processes and considerations that, in reality, belong to the treatment of the Intellect ; it being impracticable to carry on an exposition of Sense in the abstract. This is an inevitable necessity, which recurs again and again in the exposition of science. When once it is well understood, it leads to no confusion ; although, on the face of it, it has an air of irregularity, not to say paradox. The process to be afterwards explained as Association by Similarity is taken for granted in regarding each sensation as an aggregate of present and past im- pressions. In assigning the properties of sensation, we necessarily anticipate the two other great fundamentals of Intellect, — namely. Discrimination and Association by Con- tiguity ; the differences among sensations having special reference, among other things, to their behaviour in con- nexion with those great intellectual constituents. The bearing of these generalities is retrospective, no less MEANING OF COMMON SENSIBILITY. 107 than prospective ; the Muscular Feehngs above described being subject to the same considerations as the other members of the department now under discussion. General or Common Sensihility. The terms General or Common Sensibility are introduced to express a contrast occurring even in some of the five senses, but still more notably under the group of Sensations of Organic Life. The contrast is brought out on two different points. The one is the distinction between un- localised and localised sensation. In most of the senses, each sensation in the body has a local seat to which we refer it, — as contact in the skin, taste in the mouth, hearing in the ear. A common or general sensation, while a genuine item of our consciousness, points to no particular place as its seat. Examples will be furnished as we proceed. The second peculiarity of general sensation is the absence of a marked or characteristic feature, by which one sensation is distinguished in the consciousness from another. This is seen best in the pleasurable class of general sensations. A feeling of comfortable warmth over the body at large is hardly distinguished from the later stages of healthy digestion, or from the tone of elation due to a good condition of the nervous system. What we do discriminate in all sensation is degree, or amount, although the gradations as regards the present class are not very delicately marked. AYe have vague modes of exhilaration and depression scarcely distinguishable ni the consciousness from what occurs under the senses in the course of our higher emotional and active life. When we are opposed, thwarted, or balked in some enterprise or object of pursuit, we experience a con- dition of pain, having no specific characteristic to distinguish it from the depression due to our vague organic sensibilities. It is the same with the opposite condition of exhilaration from success, the overcoming of obstacles or resistance, and the attamment of much-wished objects. There may go along 108 SENSATION IN GENERAL. with such occasions some of the more definite emotions, such as the feeling of victory over rivals, the gratifying of special affections ; but, in many instances, we can discern in con- sciousness nothing beyond the very general condition of pure exhilaration. For these two opposite modes of general sensibility, we have, as already remarked (p. 75), no means of discrimina- tion or measure except Degree and Continuance. It is of very great importance to our knowledge of the workings of the mind to assign the most effectual modes of ascertaining and stating the measure or amount of the great fundamental attributes of pleasure and pain, whether in the form of vague sensibility or when accompanied by attendant differ- ences of a more specific kind. SENSATIONS OF ORGANIC LIFE. 1. The classification of these may proceed according to the parts where they have their seat, — in other words, accord- ing to the organs involved. I have already adverted to one group connected with the Muscles : these will now be de- scribed in full. Of coequal importance in our sensitive life are the feelings connected with the Organs of Digestion. Not less important is the process of Bespiration, seated in the Liungs ; although, from peculiar circumstances, less produc- tive of sensation. When we pass from these great functions to the action of the Heart and the Circulation of the Blood, we find it more difiicult to point to a special or isolated group of feelings ; nevertheless, whether as operating in their own character or as contributing to the efficiency or ineffi- ciency of other functions, the Heart, Arteries, and Veins are, more or less, causes of sensibility. The processes of Secre- tion, Assimilation, and Absorption at large, so essential to the workings of the system, in their limited alliance with nerves of sense, may be supposed to contribute a quota to the collective mass of organic feeling. Last of all, the Nerves and Nerve Centres, while being the essential seat of all OEGANIC MUSCULAR FEELINGS. 109 sensibility whatever, have a class of feelings depending on their nutrition and their waste, and the changes incident to their various states in health and disease. Organic Muscular Feelings. 2. Muscular sensibihty is manifested by the pain that is felt when a muscle is cut, lacerated, or otherwise violently injured, or when it is seized with spasm. These forms of pain are so many states of consciousness, having their seat or origin in the muscular tissue ; the integrity of the nerves and nerve centres being hkewise essential to this, as to every other kind of sensibility. In describing the sensations,— that is, the states of feeling arising through the Senses, — we shall have, in each case, to assign the external agent that causes the Sensation (hght, sound, etc.) ; to follow this up with an account of the action or change effected on the sensitive surface — as the skin, the tongue, etc. ; and, then, to proceed with a delineation of the feeling itself, according to the plan already laid down. In the case of the proper muscular sensibilities described in the foregoing chapter, an external agent could not be assigned in the same sense as hght is to the eye, or hard surfaces to the skm. But, with reference to the first class as set forth^cuts, lacerations, and violent injuries, — we dis- cern both an external agent and an assignable change in the substance of the muscle. There is, in those circumstances, a sudden break in the continuity of the fibre, which is an effect productive of pains in almost any tissue of the body. This is, manifestly, one of the effects calculated to give an in- tense shock to the nerves, originating an energetic and pun- gent stimulus, which is transmitted to the centres, and there wakens up both sensation and activity in violent forms. Such being the bodily Origin, let us complete the con- sideration of the PHYSICAL side, by attending to the outward effects or embodiments, constituting the Expression of the feeling. And the remarks on this point, as weU as the 110 SENSATIONS OF ORGANIC LIFE. further delineation of the conscious state, will serve to typify acute physical pains generally. It is well known that a characteristic expression attends Acute Pains. The features are violently contorted, the voice is excited to sharp utterances, the whole body is agitated. Sometimes, the ordinary movements are quickened ; at other times, contortions and unusual gestures are displayed. It would appear that the agency causing the pain is such as to stimulate, to an intense degree, the whole moving system. Indeed, the infliction of pain (within limits) is one of the customary modes of rousing an animal or a human being from lethargy to activity. There is also a well-known form of the countenance that marks the condition of pain, being produced by certain movements of the mouth, the nostrils, and the eyes, to be afterwards analysed ; but, whatever be the direction given to these movements, they are marked by the characteristic of violence or intensity. The accompaniment of sobbing shows that the involun- tary muscles and the glands also are affected. But we should give a most inadequate account of the embodiment of pain, if we failed to note the successive stages of the manifestation. While the first shock may have all the characters of violence and exalted energy now mentioned, there follows, after a time, a state of prostration and ex- haustion, showing that these lively manifestations are no proof of an increase of vital energy on the whole. On the contrary, it is demonstrable that, of vital energy on the whole, there is a great decrease. Violent exercises of any kind soon wear out the strength ; but the depression ' of vital power in all parts of the system— organic functions as well as muscles, — after an attack of pain, is much beyond what would follow from the same discharge of muscular energy in the absence of pain. This is a most material consideration, which is not to be disguised by the show of increased energy in the early stages. The director of the medical staff of the British Army in the Crimea was gravely in error when he discouraged the use of chloroform in surgical operations, on PHYSICAL ACUTE PAINS TYPIFIED. Ill the ground that pain is a stimulant. If the termination is taken into account as well as the beginning, pain, in every form, so far from being a stimulant, destroys the vital energies. Not only does muscular exhaustion follow, but the organic processes — the circulation, respiration, and digestion — are greatly enfeebled ; an effect that does not usually result from mere violence of bodily movement. These bodily manifestations, which are the natural ac- companiment of acute pain (arising as an effect of the same cause), by being freely indulged in, operate as a diversion and a relief to the mental system. There is, probably, a physical sequence in this fact also. Great muscular exertion draws off the circulation from the brain to the muscles ; and the effusion of tears, also, in some way reduces the congestion. We are not, however, rashly to conclude that, under great pain, a free vent to all the manifestations is preferable to forced quiescence or suppression ; there is a great expendi- ture of power under both modes. 3. To pass now to the Mental side, or the character of the states in question, viewed as Feelings. We know, each one by our own consciousness, what they are ; and they are generalised, pointed out, and understood, by such names as suffering, agony, torture. The quality of the feeling is pain. The degree is intense or acute. The measure is obtained in a twofold manner : by comparing the pain with other pains, and by attending to the amount of pleasure that it can neutralise. Either way, we consider the sufferings of wounds, lacerations, and acute derangements of our sensitive tissues, to rank among our greatest sufferings, our worst miseries. As respects speci- alities of character, we find language employed to discri- minate the nature of different pains. A cut or a scald is different from a fit of rheumatism or gout. Neuralgia is different from the electric shock. We describe the varieties by such epithets as burning, gnawing, shooting, racking ; and there is a pathological interest attaching to these distinctions. 112 SENSATIONS OF OEGANIC LIFE. Pain is apt rt>i?ouse some special emotion, varying with the jgeneral temperament of the individuah Convulsive ■"grief, rage, terror, are all liable to be awakened, sometimes one, and sometimes another ; even in the same individual, circumstances may rule the special selection. Our plan of description requires us, next, to advert to the A^olitional characteristics of acute pain. The general prin- ciple of volition, as applied to pains, holds in this instance. Such pains, in proportion to their intensity, stimulate us to efforts for mitigating and putting an end to them when pre- sent, and for avoiding them when there is danger of their recurrence. The peculiarity of the case that most deserves notice is that, since, for a time, they are stimulants of activity, the disposition to work for their abatement is very powerful at first, but fails at last with the prostration of the energies. Volition demands, not merely an adequate stimulus of pain or pleasure, but also a sufficient aixiount of active energy at the moment. The first stage of acute pain may supply this, through the exalted intensity of the nervous force ; in the latter stages of consequent exhaustion, there is a necessary failure of power, and the energy of avoidance is no longer a measure of the painful condition. The movements that constitute the proper emotional manifestations are apt to be mixed up and complicated with movements directed by the will with a view to relief. It is generall}" easy to discriminate the two classes, and it is important for understanding our mental structure that they should be discriminated. The volitional movements are such as are maintained solely because they bring a felt alleviation. If any specific posture is of this character, it is energetically adhered to ; and, if the mere vehemence of the outburst is found to deaden our sensibility to the "pain, we are induced thereby to keep up the gesticulations prompted in the first instance by the emotional Vv^ave. Even in the lower animals, when we witness the convulsions that follow a shock to the physical system, we may satisfy ourselves' as to the existence of true volitional movements, in company MEMORY FOR ACUTE PAINS. 113 with the demonstrations that are the proper embodiment of the pain. If we wish to measure the vohtional urgency of a feeHng, we can adopt the same mode of comparison as that suggested for the degree of pleasure or pain. Wlien two feelings prompt in opposite ways, the one that determines the con- duct is said to be volitionally the stronger. There remains now the bearing of the feelings in question on the Intellect. Here, as in the AYill, there is a general principle, liable to exceptions and modifications according to the circumstances of each particular case. The principle is, that feehngs are discriminated, identified, and remembered according to their degree, whether in intensity or in quantity. This law holds within a moderate range of excitement. A very feeble impression cannot be nicely discriminated, and is little remembered. But the limitation arises when the degree is excessive and overpowering. There is a pitch of physical agony that overpowers the purely intellectual function of discrimination ; and, although retentiveness is stimulated by intensity, the remembrance becomes more and more inadequate to the fulness of the reality. Not only are we unable to reinstate the acuteness of the suffering, but we are unable to figure to ourselves even the character of the pain, until it has become familiar by many repetitions. A good retentiveness for acute pains has not the intel- lectual importance possessed by the memory for sights and sounds, but it has a twofold practical importance. In the first place, on it depends the exercise of the will in the way of prevention. When a feeling ceases in the actual, it can have no volitional power, except as it is vividly presented in idea; and, on this ground, the more lively the recollection, the more energetically are we moved in our precautionary labours as regards the future. The degree of retentiveness for pain is thus the intellectual foundation of Prudence. It is, in the second place, a condition of Sympathy, or the power of entering into the feelings of others when suffering under a like infliction. 8 114 SENSATIONS OF ORGANIC LIFE. 4. The muscular pains that have been the subject of the foregoing description, are those arising from cuts, lacerations, and violent injuries, which are incidental to every kind of tissue. AVe have not included the characteristic pain of muscle — cramp, or spasm. Cramp is known to be a violent contraction of a muscle, in whole or in part, due to some irritation of the motor nerves that supply the muscle. It is a contraction probably far beyond what can be induced by a voluntary effort, and does not relate itself in any way to a power consciously proceeding from the brain. The state of cramp acts violently upon the sensitive fibres of the muscle ; and, according to Dr. Brown-Sequard, the pain is in propor- tion to the resistance offered to the muscle's contraction. ' I suppose,' he says, ' a case of painful contraction of the anterior muscles of the thigh ; the pain is increased every time the contracted muscles are elongated ; i.e., when the resistance to the contraction is augmented ; on the other hand, it diminishes when the resistance to the contraction is rendered less than it was, and at last it disappears entirely, or almost entirely, when the resistance is completely, or almost completely, destroyed ' (Lectures, p. 7). The pains in the uterus are of the nature of spasm, and are relieved by the discharge of the contents. An explanation is now afforded of what was at first considered a paradoxical fact, — the production of pain by stimulating the anterior or motor roots of the spinal nerves. The effect of such stimulation is to contract the muscles, not in that measured and moderate degree occurring in their contraction by the will, but with the violence of cramp, thereby imparting a shock to the sen- sitive nerves of the muscle. When the posterior or sensitive roots of the nerves are cut, the pain appears no longer. These explanations are interesting, as they remove what appeared objections to the discovery associated with the name of Bell. It is not requisite to repeat the particulars of the syste- matic description for this peculiar case. It ranks with the class of acute pains in all the general characters. But it is. ► FEELING OF REPOSE UNDER FATIGUE. 115 perhaps, in its nature the most acute and violent of any. We can discriminate it from cuts, scalds, inflammations, and sores ; the familiar name ' racking ' pain describes and classi- fies it. Wherever we have the experience characterised by this epithet, it is probable that the seat is in the muscles, and that the action is cramp or spasm. The involuntary muscles of the uterus, and of the alimentary canal, occasion the most aggravated forms of the pain. 5. Another class of feelings connected with the muscles may be specified under the same general head of Organic Feelings, those arising from over-fatigue. This cause is known to produce acute pains of various degrees of intensity, from the easily endurable up to severe suffering. It is not neces- sary to advert to these more specifically, as they are rendered sufficiently comprehensible when we refer them to the genus of acute pains of the muscles. They are part of the misery attending manual toil, and are also used for purposes of punishment. The characteristic state of supporting a heavy burden is a form of general depression, to which many modes of suffer- ing are habitually compared. Very dilfereut is the state of feeling produced by mere ordinary fatigue, which we may introduce in the present connexion. This is a state not at all painful, but the oppo- site. It is one of the pleasurable experiences allied with the muscular system. In this case, there is a pleasurable feeling more massive than acute. If a considerable number of the larger muscles have been in exercise, the sensibility is proportionably great. Various elements may enter into the effect. The circulation of the blood, directed strongly for a time to the muscular tissue, now returns in a more liberal supply to the other organs, — the brain, the stomach, etc., — and the general sensi- bility of the system is diverted, if not increased. There is, in the next place, an agreeable reaction from what may have been the commencing pains of fatigue. Allowing for those two collateral effects, we are still to suppose that the muscle 116 SENSATIONS OF ORGANIC LIFE. itself gives rise to a certain pleasurable feeling when in this state. The degree of it may be, on the whole, considerable. It is one of the pleasures of a life of hard exercise or bodily toil ; and, taken along with the luxurious slumbers and the general sensation of health following in its train, it must be regarded as an appreciable fraction of human enjoyment. The connexion already remarked on between slow move- ments and approaching sleep, extends also to muscular repose and sleep. The massive sensation experienced as we fall asleep maj' have its seat, in no inconsiderable degree, in the muscular tissue, especially after hard exercise, when this sensibility is most powerfully manifested. It may, however, be connected in some degree with the state of the nervous tissue which, on the approach of sleep, undergoes a notable transformation . 6. Tendons, Ligaments, Joints. — These parts, being sup- plied with sensitive nerves, give birth to a certain amount of sensibility, which is most decisively shown under severe strain, disease, or injury. A portion of this sensibility is manifested under muscular exercise, — more especiallj^ in extreme fatigue. The pains of muscular exhaustion are shown by our consciousness to be localised partly in the belly of the muscle and partly in the joints and tendons ; even the character of the different modes being to all appearance distinct. In the discussion as to the exact seat of our muscular sensibility, the participation of the joints is put forward by some as a leadnig factor. The most indubitable inference from both anatomy and self-consciousness would seem to be the concurrence of these parts in the pains of fatigue. There is, apparently, nothing to show that they contribute a share in the pleasurable side of our muscular activity ; and still less to prove that they aid us in delicate muscular discrimi- nation. Indeed, it may be affirmed that they are insensitive to the slighter forms of muscular stimulation. OBJECTS OF DIGESTION AS A SENSE. 117 Sensations of the Alimentary Canal. 7. Digestion offers all the conditions of a sense. There is an external object — the Food ; a distinct organ of sense — the Alimentary Canal, and its appendages ; and a set of Feelings, arising from the contact, also distinct and specific. To treat these feelings mider Taste, is to confomid together two senses very different in their character, although hap- pening to have one common object or stimulant. The objects of this sense are the materials taken into the body as food and drink. These materials are extremely varied, but there is no corresponding variety in their action on the stomach. They can be reduced to a few general heads, according to their composition ; it being found possible to assign a few leading substances that comprehend all the different sorts of material serviceable in nourishing the body. The following is an abstract of this classification : — 1st. Water, and the watery liquids; including substances conveyed in solution, or suspension, in water. '2nd. Saccharine substances derived from the vegfetable kingdom. These comprehend sugars, starch, gums, vinegar. 3rd. Oily substances. These include the various fats and oils, as well as alcohol. Like the former group, they are composed of carbon and the elements of water; but, in them, the carbon is in a much higher proportion. 4th. Albuminous substances, containing nitrogen : fibrine, gelatine, albumen, caseine (matter of cheese), vegetable gluten. ' All the materials which make up this group are derived generally from the animal kingdom, with the exception of the last, which is contained in great abundance in wheat ; similar if not identical principles exist in other vegetables. Wheat, indeed, consists of two substances — one referable to the saccharine group, the other to the albuminous, the former consisting of starch, the latter of gluten.' Milk is found to contain matter of all the four classes : water, sugar, oily matters (butter), caseine. 118 SENSATIONS OF ORGANIC LIFE, The three first classes are incapable of nourishing the principal animal tissues, such as nerve and muscle. They are fitted rather for supplying fat, bile, and matters used in the production of the carbonic acid that escapes from the lungs. Being supposed to be mainly destined for the supply of animal heat, by being combined with oxygen, or slowly burned, they were formerly termed calorifacient ; but this is now reckoned a too narrow view. Experiments recently made have proved that their combustion is the chief source of muscular power ; being an example of chemical com- bination transmuted into mechanical force, to which a parallel is found in the steam-engine. The same combustion may also be the source of the nerve force ; the parallel case being the voltaic circuit, where the electricity is evolved from chemical combination in the cells. The albuminous bodies are, undoubtedly, the tissue- forming material ; having a composition fitted for the purpose. But they are not confined to this function ; in their final transformations and decay, they may be at last oxidised and become the source of heat, muscular force, and nerve force, like the others. Certain substances of the saline, earthy, or mineral class, are requisite ; most of them being found in the usual articles of food. Salts of soda, potash, and lime, as well as iron and phosphorus, are essential ingredients. The Stimulants are classified into spices, or condiments ; vegetable alkaloids, as tea, coffee, cocoa ; extractives, as creatin and creatinin, occurring in the juice of meat; and the alcoholic beverages. For the most part, these substances are not directly nutritive ; they act as stimulants to the nervous system, and also retard the waste of tissue. The orgaiiic vegetable acids, — vinegar, the acids of fruit, and lactic acid, — are in extensive use as an ingredient of food. The differences that' exist among the infinity of articles used as food are not, at bottom, so great as they seem. If we take the different species of grain, — wheat, barley, rye, oats, rice, maize, millet, — we shall find that they are all composed ORGANS OF DIGESTION. 119 of the same ultimate materials, gluten and starch, though not in the same proportions. In like manner, the potato is a starchy vegetable, with a very small share of gluten : hence, it is defective as an exclusive article of diet. Another difference among vegetables relates to their texture, as fitting them for being acted on during mastication and digestion, — a circumstance, however, that cooking can modify. Thus, the potato is a much looser texture than grain. A third point of distinction among alimentary sub- stances, is the extraneous essences that may enter into them, and affect the sense of taste, and the general relish,^ — ■ as in the difference between mutton and beef, chicken and venison, brandy and rum. 8. I extract from Quain's Anatomij the following general view of the Organs of Digestion. 'The digestive apparatus includes that portion of the organs of assimilation, within which the food is received and partially converted into chyle, and from which, after the chyle has been absorbed, the residue or excrement is expelled. It consists of a main or primary part named the alimentary canal, and of certain accessory organs. ' The alimentary canal is a long membranous tube, com- mencing at the mouth and terminating at the anus, composed of certain tunics or coats, and lined by a continuous mucous membrane from one end to the other. Its average length is about thirty feet, being about five or six times the length of the body. The upper part of it is placed beneath the base of the skull, the succeeding portion is situated within the thorax, and the remainder is contained within the cavity of the abdomen. In these several situations, its form, dimensions, and connexions, its structure and functions, are so modified that certain natural divisions of it, bearing different names, have been recognised by anatomists. ' It may be considered as composed of two parts : one situated above the diaphragm, and the other below that muscular parti- tion, and therefore within the abdomen. The first division consists of the organs of mastication, insalivation, and deglutition ; and comprises the month, the pharynx, and the oesophagus, or 120 SENSATIONS OF ORGANIC LIFE. gullet. The second division consists of the organs of digestion, properly so called, and of those of defascation ; viz., the stomach, the small intestine, and the great intestine. ' The accessory parts are chiefly glandular organs, which pour their secretion into it at different points. They consist of the salivary glands (named the parotid, submaxillary, and sublingual). the liver, and the pancreas. Besides these large glandular organs, a multitude of small glands, compound, follicular, or tubular, are collected together at certain points, or scattered over large por- tions of the inner surface of the alimentary canal : these are described along with the mucous membrane of each part. The remaining accessory organs are the teeth, the jaios, the tongue, and the spleen.' 9. The physiology of digestion operated by the concur- rence of these various organs is complicated in no ordinary degree ; the general health and ethciency of the body being very largely dependent upon the proper v^^orking of the vari- ous processes. Likewise, the concurring sensations are highly important as regards our consciousness, w4iether pleasurable or painful. This department of sensibility may be, to some extent, analysed and defined for purely psycholo- gical purposes. The scheme of analysis turns upon the local distinctness of the various processes, and upon the circum- stance of their being more or less supplied with sensitive nerves. The following is a view of the several known stages that would appear to enter into our distinctive conscious- ness more or less, or maybe conveniently cited as, in all pro- bability, embodying separable modes of digestive sensibility. The first stage is mastication, which serves the double purpose of breaking down the food and of mixing it with saliva. The function of the saliva is now known to be, to convert the starch into grape sugar, by a process of the nature of fer- mentation. The effort of mastication is purely voluntary ; but, when the food gets upon the back of the tongue, it is passed into the bag of the pharynx and propelled down the gullet into the stomach by involuntary muscular contractions. The arrival of the food in the' stomach causes a flow of PHYSIOLOGY OF DIGESTION. 121 gastric juice. This, already commenced during mastication in the mouth, increases as the food accumulates in the stomach itself; as, by the churning and further gastric movements, one part after another of the material is brought into contact with the mucous membrane. The composition of the gastric juice is known to be partly hydrochloric acid and partly a special ferment called ' pepsin '. The gross effect of gastric digestion is to break up, and, in part, to dissolve, the large lumps of masticated food into a thick, greyish, soup-like liquid, called chyme, — with which are still mixed, in variable quantity, larger and smaller masses of less changed food. ' During gastric digestion the chyme thus formed is from time to time ejected through the pylorus, accompanied by even large morsels of solid, less digested matter' (Foster). It now enters the duodenum, into which are poured the bile and the pancreatic juice. By these fluids further important changes are brought about, as the mixture proceeds along the small intestine. The effect of the pancreatic juice, which is poured into the small intestine nea.r its commencement, is to co-operate with the salivary glands in w^orking upon the starchy con- stituents of the food, and to contribute to the digestion of the fat. The functions of the liver are more complex. The bile is strongly antiseptic ; mixing with the fatty matters of the food, it is indispensable to their being absorbed in the intes- tines. The liver is further believed to form sugar out of other elements passing into it by the circulation. The blood from the intestines, before returning to the heart, passes through the liver, and takes up the sugar formed independ- ently there. In the stomach, and along the intestine, there is a two- fold absorption proceeding. The one mode is by the lacteal vessels : these have the exclusive power of taking up the fatty matters, which constitute the chief part of the cliylc, as their contents are named. The other mode is by the capil- 122 SENSATIONS OF ORGANIC LIFE. lary blood-vessels : through these, the nutritive matter is taken at once into the circulation, reaching the heart through the liver. By the time the food reaches the end of the small intes- tine, it is largely, but not wholly, deprived of its nutritious constituents. In the large intestine, or colon, absorption is still going on. ' By the abstraction of all the soluble consti- tuents, and especially by the withdrawal of water, the liquid chyme becomes, as it approaches the rectum, converted into the firm, solid faeces.' An essential feature of the digestive tube is the distribu- tion of involuntary muscular fibres for propelling the con- tents of the stomach slowly along. This is named the peristaltic motion. Upon its regular and efiicient working, greatly depends the goodness of the digestive changes. Sluggishness, on the one hand, and morbid activity, on the other, are inimical to the numerous secreting and absorbing operations entering into the final result. Cerebro-Spinal, — that is to say, sensitive, — nerves are supplied largely to the stomach, and, sparingly, to the re- mainder of the alimentary canal ; being mixed with nerves from the sympathetic system, by which the various processes are mainly regulated. The vagus nerve is the medium of our digestive sensibility, and indicates to our consciousness the character and amount of the various alimentary changes. That our sensibility is not confined to the stomach, although most copious in connexion with it, owing to its greater abun- dance of sensitive nerves, is proved in various ways. States of acute pain are induced at any point of the stomach and intestine ; any violent derangements, — such as colic or mus- cular spasm, — affect our consciousness in an unmistakable form. It is a natural inference that the same nerves are sen- sitive also to the other great changes attending the course of the food through the whole length of the alimentary canal. The immense variety and amount of digestive states that we are made aware of could not proceed from the nerves of the stomach alone, wliere the cycle of operations has made only FEELINGS OF HEALTHY DIGESTION. 128 a commencement. The consequences of the introduction of bile and pancreatic juice, so essential in the subsequent stage of the digestive process, cannot fail to be appreciated by our direct consciousness. When these are of a morbid character, they too are productive of great and manifest forms of pain. On the other hand, the healthy and genial modes may be supposed to occasion some portion of the pleasurable glow obtainable through the digestive sensibility. It is also known that stimulation of the vagus nerve brings about contractions in the small intestine. 10. And, now, with regard to the Feelings of Alimentary action. These are mostly of the pleasurable kind, when the action is healthy ; pains are the result of disease and disorder. Beginning with the sensation of taking food, we shall find a pretty general agreement as to its character. I do not speak of the feeling of Taste, but of the sensibility connected more particularly with the stomach and alimentary canal, which extends even to the mouth in connexion with saliva- tion, and is called relish. If we include the entire mass of sensation arising from a healthy meal, and lasting a certain time after the meal is finished, at which stage the operation of digestion in the stomach is the sole cause of what we feel, we may safely pronounce it to be an agreeable state of a high order. It has the characteristic of massiveness, or quantity ; being a rich, luxuriant, satisfying sensation. Such is the character common to all kinds of healthy nourishment ; but there is the greatest possible difference in the qualities of food as regards stomachic relish : from turtle to stale oat- cakes, or a piece of black bread, what an interval ! To the richer kinds of food, belongs a feeling intense as well as voluminous. The magnitude of the sensation is attested by its ability to submerge a great many irritations, and to make itself for the time the ruling element of the consciousness. This power brings it into comparison with such feelings as healthy exercise and repose, nervous elation, and the intoxi- cation of warmth. 124 SENSATIONS OF ORGANIC LIFE. The energy of the Vohtion corresponds to the rehsh and to the stage of the operation. At first, the active stimulus is intense and even furious. Appetite is inflamed by partial gratification ; and, until such time as the stage of fulness draw^s near, the pleasure shov^^s itself in supplying impulse to continue it. Eating is among the most characteristic examples of the general law of feeling-prompted activity ; being not only for the suppression of pain, but also for the retaining and heightening of pleasure. To complete the delineation of this mode of consciousness, v^^e may notice the peculiarity of it as related to the Intellect. Here, however, we have only to remark, as in other cases, that there is comparatively little permanence in idea, when the state of the organs is such as to forbid the reality. But the reality is one that never is long absent. As a general rule, it is true of digestive and all other organic sensations, that they are exceedingly powerful when present, and ex- ceedingly little realised when absent. They are thus unlike sights and sounds, loves and hatreds, and other states that the intellect can retain in the ideal form. To imagine with effect the relish of a feast when under nausea, passes the power of the most vigorous memory. The sensation connected with the lower extremity of the canal is chiefly of the nature of a feeling of relief from pain. 11. Another important healthy sensation of the aliinent- ary canal is Hunger, — the state preparatory to the one just described. The physical concomitants of hunger are a collapsed condition of the stomach, usually accompanied with a de- ficiency of nutritive material in the system. The sensitive nerves distributed to the mucous surface of the stomach are first affected ; then the nerves of the lower intestines ; and, finally, an influence of the general system adds to the pain and the feeling of depression. It is considered probable that the state of the muscular fibres of the stomach makes a part of the case (Weber). These are at first loose and uncon- tracted ; but, at a later stage, their characteristic (peristaltic) HUNGER. 125 movements are commenced upon the empty tube. The cutting of the nervus vagus (supplying the mucous surface) does not entirely abolish the feeling of hunger. The feeling itself is of the uneas}' or painful class, with a degree of massiveness and engrossment corresponding to stomachic feelings in general. The appetite for eating commences with a pleasant feel- ing, and consists of certain indefinite sensations in the region of the stomach, accompanied by stimulation of the muscles of chewing, and by the secretion of saliva. If ungratified, this passes next into an uneasy feeling ; then come on op- pressive gnawing pains, which are referred to the region of the stomach ; these are followed by sensations of a still stronger kind, derived from a more general action, under which the local feelings are submerged. Animals are driven in search of food after the nervus vagus is cut ; which would seem to imply that the sense of starvation in the body generally is a part of the motive power of hunger. On the other hand, it is contended that, when the digestion is diseased, the appetite for food may be entirely wanting, however much the frame be suffering from want. The influence. of the nerves and the nerve centres is shown in the fact that a desire of eating may exist when the stomach is full. In ordinary circumstances, the state of fulness of the stomach is followed by the sensation of Satiety. It is to be distinctly understood that, although the supply of materials to the blood is the final end of all the digestive pro- cesses, yet the digestive pleasures and pains, and the accompany- ing cravings or appetites, are regulated, in the first instance, by the stomach itself — its secreting surfaces and its nerves. There is often a rivalry or inconsistency between the interests of the stomach and the interest of final nutrition as determined by the state of the other organs. Habit, in a great measure, determines the recurring periods of hunger : at these periods, the craving arises irrespective of the needs of the system. Moreover, what pleases the stomach is not necessarily the most suited to the general reparation of the tissue ; while, obversely, materials of 126 SENSATIONS OF ORGANIC LIFE. the highest nutritive quality — as cod-liver oil, in certain states of the system — may be very repugnant to taste and digestion. It is further to be noted that the long series of digestive pro- cesses whereby the food material is prepared for assimilation and absorption occupies time, — say, several hours. Nevertheless, an instantaneous stimulus to the general activities may arise imme- diately after taking food ; implying that a portion of the food material passes at once into the circulation, so as to afTect the nerves and muscles in advance of the contribution of the general mass of the food (see Foster's Physiology, 5th edition, p. 1423). 1'2, The feeling of Nausea and Disgust is an effect indi- cating some great disturbance in the usual course of digestive operations. This state is associated with the act of vomiting ; an act that may take place — ' (1) From the introduction of cer- tain substances into the stomach, some of which, as bile, mustard, common salt, not becoming absorbed, must act simply by the impression they make on the mucous mem- brane ; (2) By the introduction of emetics, as Tartar emetic, into the blood, or by the presence of certain morbid poisons in the fluid ; (3) By mental emotion, as that excited by the sight of a disgusting object ; (4) By irritation at the base of the brain ' (Todd and Bowman, ii. 214). To these must be added sea-sickness. Inflammation of the brain in children usually shows itself first in violent vomiting. The act of vomiting is the result of a reflex stimulus, directed towards the muscles that compress the abdomen in the act of expira- tion of the breath. These muscles violently contracting, while the exit of the air from the lungs is shut up, squeeze the contents of the stomach upwards towards the mouth. The sensation of vomiting is, in most cases, horrible in the extreme. It proves by a strong instance the power of stomachic influences on the nervous system. The sensation is one sui generis — no other feeling can at all compare with it. There are many forms of unendurable pain, but this (at its full height) has a virulence of its own, great both in quantity and in intensity. On the maxim that the abuses of the best things are the worst, the wretchedness of stomachic DISGUSTS. 127 perversion might be taken to be a testimony of the aptitude for pleasure belonging to this part of the system. The sensations of nausea are also accompanied by irre- gular movements of the muscles of the pharynx. These are the seat of the characteristic feehng of nausea. In the stomach also, the sensation may be connected with irregular, or anti-peristaltic, movements in the muscular fibres. The feelings of nausea and disgust, and the objects causing them, are expressed in our language by a variety of strong terms. The 'disagreeable' is, originally, what revolts the stomach, though extended in its application to other forms of the unpleasing. ' Disgust ' is the extreme opposite of relish. The fact that these words are among the strongest that the language affords to express dislike or aversion, proves how deep and intense is the feeling that they primarily refer to. Besides the objects that produce disgust by actual contact with the alimentary canal, there are substances whose appear- ance to the eye is disgusting. Certain gases also affect the smell in the same way. Disgusting sights are mostly the result of association ; but some nauseous smells act from the very beginning. The arrangements of human life particu- larly address themselves to our protection against disgusts ; and, singularly enough, the chief things to be avoided are the products of living bodies themselves. This is the foremost aim of the operations of cleansing and the removal of refuse. The influences that stimulate a healthy digestion and relish are contrasted with their opposites by the term 'fresh,' — which also applies to respiration, but which has still more emphasis as opposed to the causes. of disgust. The power of resisting nauseating influences is an indication of great stomachic vigour in the right direction. There are many things entering into the ugly, or opposed to the beautiful ; but nothing contrasts with beauty so en- tirely, or annihilates it so effectually, as a disgust. 13. The foregoing cases are intended to include the most prominent of our habitual and ordinary experiences in rela- 128 SENSATIONS OF ORGANIC LIFE. tion to the alimentary processes. With regard to the feelings arising from disease in the various organs of digestion, these are so many forms and varieties of pain. If we were to go systematically through the entire series of organs already enu- merated, we should have to commence with mastication, and describe the pains and agonies which the teeth render familiar to us. Distemper of the salivary glands yields a sensibility, not of the acute kind, but annoying, and difficult to bear, like disordered secretions in general. The pains and disorders of the early stages of digestion, that is, in the stomach, where the sensitiveness is greatest, are very numerous, and are sometimes acute, but oftener not so. In proportion to the genial influence of a healthy digestion upon the general mass of sensibility, is the malign influence of an unhealthy diges- tive action. It is in extreme cases altogether overpowering, and renders futile almost every attempt to establish a pleasur- able tone by other causes. The nervous connexion between the brain and the stomach, being intimate and powerful, shows itself in many ways. Not only is there a keen sensi- bility to stomachic states, but also a strong retu7'ning influence from the brain upon the digestive secretions in the way of supplementing their force, or aiding them by a stimulus from without. On acute stomachic pains, it is not necessary to spend much discussion. They have their character chiefly from the great sensibility of the alimentary surface, which often makes a slight cause of irritation peculiarly keen and in- tolerable. On the subject of pains and distempers not acute, but connected with want of tone and vigour in the digestive system, or with deranged mucous surface, the pathologist and physician have much to describe. The stomach combines the nourishing and the purifying functions ; and, hence, operates doubly upon the healthy condition of the blood — the general basis of bodily and mental vigour. A well-known form of depression accompanies deficiency in the excreting power of the alimentary canal ; so much so, that a forced relief of the loaded organs produces a general exhilaration, — OBJECT OF RESPIRATION AS A SENSE. 129 the consequence of withdrawing impurity from the blood. But what chiefly interests us is to mark, as a specific mental experience arising out of many forms of alimentary derange- ment, the depression and ennui spread over the consciousness, at the times when any of these organs are failing to perform their part. This effect is one that, if not intense or acute, is powerful in its amount, and extremely ditiicult to combat, either by other stimulants or by the action of the mind recalling or imagining situations of a less gloomy cast. It either resembles or else produces that physical depression of the nervous substance to be afterwards considered ; the likeness holding remarkably in the leading features, as in the distaste for existence while the state lasts, and in the extreme facility of forgetting it when it is gone. In the rational point of view, hardly any sacrifice is too much to prevent the frequent recurrence of this state ; but so little hold does it take as a permanent impression, that the reason has very little power in the matter. Any feeling of general depression is easily forgotten, when the animal spirits are restored ; the evil then seems to have neither a local habitation nor a name. Feelings of Bespiration. 14. ' Respiration is that function by which an interchange of gases takes place between the interior of an organised being and the external medium ; and, in the animal kingdom, oxygen is the gas received, and carbonic acid the gas given out.' The aeration of the animal fluids or juices is an essen- tial of their vitality. If this is put an end to, death ensues instantaneously ; if insufficiently performed, the vigour of the animal is lowered, and a peculiar painful sensation expe- rienced. In man and in air-breathing animals, there is a wind-apparatus, the lungs, inflated and contracted by muscles, so as to suck in and force out the air by turns. In this action, we have all the particulars necessary to constitute a Sense : an external object — the air of the atmo- sphere, — which operates by physical contact upon the lining 130 SENSATIONS OF ORGANIC LIFE. membrane of the tubes and cells of the lungs ; nn organ of sense ; and a resulting state of feeling, or consciousness. The peculiarity of the case lies in its being almost entirely an emotional sense ; generating feeling, rather than yielding knowledge, or providing forms for the intellect ; ranking, therefore, among the lower, and not among the higher, senses. As respects the object of this sense, the external air, it need only be remarked, that the air differs considerably in its quality for breathing purposes ; the chief point of differ- ence being expressed by the term ' purity '. The purity is affected, first, by the loss of oxygen, which happens when the same air is repeatedly breathed, or otherwise consumed ; secondly, by the accumulation of carbonic acid, from the same circumstance ; and, thirdly, by the presence of foreign gases and effluvia arising from animal life, vegetation, or other causes. Confinement in the surroundings is the chief aggravation of all those impurities. Of the three evils — the loss of oxygen, the accumulation of carbonic acid, and the generation of effluvia of animal and other substances, — the second is the least injurious ; for, although the production of a carbonic acid atmosphere, by burning charcoal in a close room, is fatal to life, yet the quantity usually occurring in rooms is not found to do any harm, if mixed with air other- wise pure. The loss of oxygen, and the diffusion of the gases of decay, are the main influences that deteriorate the atmosphere. Of the organ acted upon, the lungs, a minute description is not necessary for our present purpose. The structure is so arranged by ramifications and doublings as to present a very extensive surface to the air ; the surface consisting of a fine membrane, with capillary blood-vessels thickly distributed. The exchange of gases takes place through the double medium of membrane and capillary tube. The muscular apparatus for sustaining the bellows-action is the diaphragm and ab- dominal muscles, and the muscles of the chest or ribs. The integrity and vigour of these muscles, and of the nerve centres FEELINGS OF RESPIRATION. 131 that sustain and time their action, must be reckoned as a condition of healthy respiration. The respiratory nerve centres, which are capable of acting when all sensory channels are cut off, are stimulated from the body at large, but chiefly from those parts that, like the muscles, are large consumers of oxygen. The portion of the eighth pair of nerves named the nervus vagus (or pneumo- gastric), is instrumental in keeping up the rhythm of the lungs, and is also necessary to the feeling of suffocation. The feelings of Respiration, both pleasurable and painful, are well marked. They include the gratification from pure air, enhanced by the increased action due to muscular exer- cise ; the various shades of oppression from overcrowded rooms and unwholesome gases ; the distressing experience of suffocation, or want of breath ; and the pains attendant on disease of the lungs. 15. The influence of pure and stimulating air abundantly inhaled, spreads far and wide over the system, elevating all the other functions by the improved quality imparted to the blood. The indirect consequences do not altogether hide the grateful sensibility arising from the lungs themselves, and referred by us to the region of the chest, — a sensation not very acute or prominent, but possessing that choice and well- know^n quality expressed by the term ' freshness' or ' refresh- ing '. This quality manifestly implies a contrast ; for, it is felt only when we pass from a lower to a higher degree of aeration. We may experience it at any time, by holding in the breath for a little and then allowing it full play. No technical nomenclature can increase the conception possessed by every one of this remarkable sensibihty ; but, for the sake of comparison with the other parts of our mental constitution, an attempt at verbal description is necessary. As just re- marked, the sensation turns upon the contrast of the greater activity of the lungs with an immediately preceding activity of an inferior degree. It may be affirmed that no feeling arises from the lungs, after a given pace has been estab- lished for a length of time ; but any acceleration of the rate of 132 SENSATIONS OF OEGANIC LIFE. exchange of the two gases (by no means depending altogether on the rate of breathing) does for a time yield that delightful freshening sensation, which tells so immediately on the mental system as a contribution to our enjoyment, and as a stimulus to our activity and to our desire for rural recreation and bodily exercise. The remark already made regarding Digestiou applies, al- though in a smaller degree, to Eespiration. The immediate cause of the sensation, whether pleasurable or painful, is due to the influence exerted on the brain by the nerves concerned in the act itself ; in other words, it does not depend on the ultimate effect upon our physical well-being, or on the changes in the constitu- tion of the blood. This final interest would, undoubtedly, suffer by a considerable prolongation of the stoppage of the breathing, but would not begin to suffer seriously at the moment when the sus- pended action of the lungs has become intolerable as a sensation. Doubtless, in no very long time, the intermission of the supply of oxygen, and the accumulation of carbonic acid, would render the blood unfit for the sustenance of the other vital organs. 16. The feelings of insufficient and impure air are mani- fested in the forms of faintness, sense of exhaustion and weariness, and are, obviously, due, not to the lung-sense alone, but to the lowered condition of the body at large. The characteristic sensibility of the lungs is shown in the state termed suffocatioyi, arising from the want of air, as in drowning, in an atmosphere deteriorated by such poisonous gases as chlorine or sulphurous acid, in attacks of asthma, and in voluntarily holding in the breath. ' After holding the breath for fifteen or twenty seconds during ordinary respiration, or forty seconds after a deep respiration, there arises an insup- portable sensation over the whole chest, concentrated under the sternum, and no effort can maintain the interruption of the respiratory acts. This urgent sensation of want of breath, when carried to its full extent by any mechanical impediment to the aeration of the blood, is one of the most painful and oppressive kind, and is referable to the pulmonary FEELINGS OF CIRCULATION AND NUTRITION. 188 plexuses (of nerves) distributed to the bronchia, and perhaps on the walls of the lobular passages and cells. The impres- sion made on these peripheral nerves by the absence of oxygen, and the undue presence of carbonic acid in the air in contact with them, is propagated to the spinal cord and medulla oblongata by the sympathetic and vagus, and there excites those combined actions of the muscles of inspiration which lead to the renewal of the air ' (Todd and Bowman, ii. 403). The sensation is of the class ' racking pains,' and may be, in part, muscular. Circulation and Nutrition. 17. When we endeavour to detach this function from the closely allied processes of Digestion and Respiration, we find, to begin wdth, a purely mechanical function, — namely, the pumping action of the heart, by which the blood is made to perform its rounds through all the organs of the body. The heart itself may be independently powerful, or the reverse ; and the consequences must be distinct and specific. Probably, however, the resulting consciousness is not equally distinct. While decided failure of the heart's action may be shown in severe local pains, slight fluctuations in its average efficiency give no conscious indication. The final results of digestion and respiration are to de- posit in the blood the solid, liquid, and gaseous material that constitute its nutritive qualities. Deficiency in any impor- tant constituent, say water or air, leads to decided and painful sensations. The mischief that is caused properly appertains to the various tissues of the body, which are thereby de- prived of their proper nutriment ; but, in the absence of any distribution of influence of such a pervasive character, the actual sensibility is in a great measure localised. Take the case of the deficiency of water. The powerful sensibility of thirst is apt to be localised in the mouth and palate. Be- yond this, it arises from the body at large in the shape of vague, common sensibility, determined by rousing this very feeble 134 SENSATIONS OF OEGANIC LIFE. consciousness into serious amount by the extent of the disor- ganising influence. In hke manner, the state of hunger, which has its acute manifestation locaHsed in the organs of digestion, is augmented by a more general wave of sensibi- lity, when the want of food leads to inanition or starvation in the body at large. It is from such considerations as these that we seem entitled to regard the circulation of the blood as an organic function, apart from the functions of those other organs that are in such intimate relations with it, either giving or receiving mutual aid. Heat and Cold. 18. Changes of temperature usually affect us through the skin ; and hence sensations of warmth and coolness are treated as a leading branch of our cutaneous sensibility, as will be seen under the sense of Touch. Still, the importance and the range of those feelings cannot be sufficiently ex- pressed while confined to our tactile sensibility. They take a very high rank in the department of the organic feelings, not much inferior to the classes already dw^elt upon. A\^iile mingling with the other contributing elements of general sensibility, the}^ nevertheless, possess a unique characteristic in the conscious tone, and can be, in most cases, discerned apart from the other constituents of the moment. Inasmuch as cold (not in excess) increases the activity of the muscles, the nerves, the respiration, and the digestion, the animal powers attain their maximum in cold climates, and in the winter season, allowance being made for constitu- tions unfitted to endure extreme depression of temperature. Sudden changes of temperature derange the functions. A sudden increase will cause a slight feeling of suffocation, beating of the heart, and increased pulsation and respiration. A sudden chill makes breathing difficult, quick, and irregular, and increases the pulsations. The nerves lose their excita- bility both under a great depression and under a great increase of temperature. SENSATIONS OF HEAT AND COLD. 185 Cold, or chillness, is a feeling altogether unique, whether as a localised cutaneous sensibility or as an influence affect- ing at once all parts of the body that share in the suscepti- bility. When, from being in a medium or normal tempera- ture, we are suddenly subjected to general cooling, say a cold atmosphere, there is a massive pain, serving to depress the entire tone of the moment, while the speciality of the feeling is such as to discriminate it in a marked way from other modes of general depression. No doubt, a great and sudden chill deranges more or less several of the vital organs, and these, through their sensitive nerves, will make their altered character known to the consciousness through the brain. Yet, such effects are not the sources of the feeling proper to an alteration of temperature, while they scarcely disguise its familiar characteristic. The natural heat of the blood is about 98°. Any con- tact below this point feels cold ; any contact above it feels warm. There is a certain surplus heat generated in the human system, which enables us to live in a medium below 98', without feeling cold ; and, if this heat be husbanded by clothing, a very great depression of external temperature may be endured. A room is warm at 60". The outer air can be endured at freezing and far below, either by means of exercise, which evolves heat, or of clothing, which re- tains it. An acute cold acts like a cut or a bruise, injuring the part affected, and causing painful sensations of the class arising from violent local injuries. The temperature of freezing mercury w^ould destroy the skin, like boiling water or a sharp cut. The proper sensation of Cold arises from a general cool- ing of the body, or any considerable part of it, below blood heat. The term ' chillness ' expresses the state of feeling, which is of the painful class. The degree is not acute, but massive. In the worst forms, it is wretchedness in the ex- treme. To a person suffering from excessive chillness, some powerful stimulant, such as the taking of food, alcohol, or 136 SENSATIONS OF ORGANIC LIFE. tobacco, is necessary to restore equanimity. The volition and the memory are proportionally impressed by the pains of cold, and they take a high rank in the reckonings of fore- thought and prudence. It is a singular fact in our constitution, that an agency calculated to quicken the vitality of so many leading organs — muscles, nerves, lungs, stomach — should affect us so power- fully, by the depression of one organ. The fact is highly illustrative of the importance of the skin, — whether from its organic functions, or from its sensibility. Probably, both circumstances enter into the case. It may be that the quickened vitality of all the other leading organs is unavail- ing for a perfectly healthy tone while the skin is depressed. But it must be also true, that we are in a peculiar degree sensitive to changes in the condition of the skin, — owing, no doubt, to its great supply of nerves. 19. The consequences of Heat are, in nearly every parti- cular, the opposite of those now stated. Acute or intense heats agree with intense colds in being simply destructive and painful. Within the point of injury to the tissues, heat is a pleasurable sensation. The pleasure of heat, like the pain of cold, is voluminous or massive. There are cases, however, distinguished by intensity rather than by quantity ; indeed, this distinction of quantity and intensity, used as a part of the description of feelings, has its perfect type in the case of temperature, there being a physical reality correspond- ing to the mental facts. Sometimes, we have great intensity and small quantity, — as in the scorching rays of a fire, or a cup of hot tea : at other times, we have large quantity with low intensity, — as in a hot bath, a warm room, a warm bed. The hot bath is the extreme instance. By no other contrivance can such a mass of heat be brought to bear upon the human system ; consequently, this presents the sensation of warmth in its most luxurious form. It is the intoxication of animal heat. We are, unavoidably, led to assume that this warmth must act powerfully on the sensitive nerves ; for, it is hardly to be supposed that the organic processes are so greatly SENSIBILITY IN THE NERVE SUBSTANCE. 187 furthered by the sustained temperature as to exalt the plea- surable consciousness in this remarkable degree. Indeed, we may derange the system by excessive heat, without producing the painful feeling arising from cold. In the case of morbid activity of the nervous system, warmth is a soothing influence, either by its physical effects, or by the nature of the sensation, or from both combined. The feelings of Respiration, and those of Heat and of Cold, illustrate in a marked manner the fundamental doctrine of Eelativity, or of change as a condition of consciousness. There is no feeling of respiration, nnless by increase or diminution of the action of the lungs ; and, if we lived in an even temperature, heat and cold would be alike unknown. The induction of the principles of Relativity as regards these states is complete. Sensations of Nerve. 20. The nerves and nerve centres, apart from their action as the organs or medium of all human sensibility, have a class of feelings arising from the organic condition of their own tissue. Wounds and diseases of the nerves are pro- ductive of intense pains ; witness tic-douloureux and the neuralgic affections of the brain and spinal cord. Nervous exhaustion and fatigue produce a well-known sensibility, very distressing in its extreme forms ; and repose, refresh- ment, and stimulants engender an opposite condition, through a change wrought on the substance of the nerve tissue. The nervous pains arising from cuts, injuries, and disease of the substance, are characterised by a most vehement intensity. When a muscle is spasmodically contracted, the influence passes from the muscular fibres to the nerve, and the affection of the nervous fibres may then be supposed to be secondary ; but, in neuralgic affections, the influence comes at first hand, and not by propagation from some other tissue. We have here, therefore, a manifest complication to deal 138 SENSATIONS OF ORGANIC LIFE. with. The nervous substance is necessary to all sensibility : strictly speaking, every form of pleasure and of pain is physically embodied in a certain condition of the brain and nerves. But we have to note, under the present head, the effects that arise from operating upon the tissue directly, and not through the organs of sense, or by means of the emotions. This direct action is exemplified in injuries and in diseases of the nerves, in the use of stimulating drugs, and in the agencies whereby the cerebral substance is nourished or impaired. The action and reaction of the different organs connected with our physical well-being tends to confuse the sources of our sensi- bility. Nevertheless, important ends are served by endeavour- ing to assign to each its part in the complex results ; and, although this is often difficult, it is not impossible. We know, for example, when a sight or a sound that experience shows to be pleasurable in its tendency may, on some special occasion, utterly fail to pro- duce the customary effect. We readily refer the circumstance to the organic condition of the nervous substance for the time being. When a physician finds a patient in a mood of great mental de- pression, his cross-examination usually enables him to assign the special organ that is at fault. It may be the digestion, the respiration, the circulation, or the nervous substance itself, which is no doubt dependent upon these other leading functions, but may, from some peculiar cause, be lowered in tone, notwithstanding the sufficiency of the other organs in their proper spheres. 21. Nervous Fatigue, or Exhaustion. — This state is con- sequent on too great expenditure in some one or other of the numerous forms of nervous activity, on intense pains, on excesses of pleasure, on long-continued activity of either body or mind, on reaction from stimulants. It may, also, arise from want of proper nourishment of the nerve substance ; and this, again, may be either a want of food material or an insufficient preparation by the auxiliary organs of nourish- ment. The mental state most usually corresponding to such a condition is simple depression of tone, or massive pain of the HEALTHY CONDITION OF THE NERVES. 139 nature of general sensibility. Although very readily passing into acute forms of nervous pain, as simple headache, it may yet be free from all such local and special peculiarities ; its sole means of distinction being degree or amount. Here, then, may be an extensive scale of gradation, which has a momentous import as affecting the entire tone or sense of existence. Our consciousness makes us aware both of the state itself and of its amount ; and, notwithstanding the absence of specific characters, there are ways and means of stating and fixing this amount over and above the feeling of the moment (see p. 75). Healthy and Fresh Condition of the Nerve Tissue. 22. This is, in every respect, the opposite or obverse of the foregoing, — whether we look to the physical and mental sources or to the resulting consciousness. General exhilara- tion of mental tone, which is connected with high or effective condition of the Digestion, Respiration, or Circulation (for which, of course, the nervous substance must be the support in the end), may be, at times, distinctly referable to the good condition of the nerves and brain in their own proper capacity. This fact can be established beyond dispute by the case when these other organs are even below their normal condition, while yet the nerve substance responds to joyous elation. The decisive example is, of course, the operation of stimulating drugs. Less prominent, but still suggestive, are the numerous occasions when we are aware of having undergone nervous renovation, undisguised by an improved condition of the other functions. The influence of stimulating drugs is usually a mixture of general (pleasurable) sensibility with distinctive modes that give a certain character to different kinds of stimulants. At- tempts have been made to specify and delineate the psychical results of the principal stimulants in habitual use. The cir- cumstances that give a variety of aspect to these are such as the following. For example, it is well known that a stimu- lating substance may be more or less purified from gross or 140 SENSATIONS OF ORGANIC LIFE. irritating accompaniraents, such accompaniments being of the nature of so much painful agency detracting from the general effect. More commonly, however, the result is to bring about a speedier exhaustion of the nervous system, and so terminate the period of exhilaration due to the stimu- lating substance ; persistence then inducing either nervous depression or acute nervous pains. Another important type of stimulation may be specified as general sensibility, of a soothing, satisfying, and quieting character ; the contrast to which is a stimulation that is exciting, in the sense of demanding some other applications in order to give perfect satisfaction, — as, for example, the gratification of some favourite study or some personal interest beyond the moment. In such a case, the stimulation is manifestly inadequate as pleasure, while setting nervous currents in motion, as pure excitement ; thus determining a state of wakefulness that needs occupation and desires some further consequences in the way of pleasurable awaken- ing. To evoke a perfectly pure condition of pleasure, in con- siderable amount, and of a kind to allay all further cravings for the time being, needs a rare conjunction of circumstances, especially if some continuance is counted on. In nearly every mode of arousing pleasurable sensibility, there is some mixture or dross, to which corresponds a separate demand in order to get rid of it. The modes of stimulation by substances of the nature of drugs to the nerves are distinguished, intellectually, by the discriminative operation of such drugs on the senses affected. From this cause, associations spring up between the purely pleasurable stimulus and sensations that have an intellectual persistence, whereby the more emotional effects may be lodged in the memory and reproduced as recollections. This remark will find additional illustration under the Five Senses. Otherwise, we may say of nervous stimulants, as of pleasurable and painful sensibility generally, that the intellectual persistence of the psychical conditions is of the lowest order. SLEEP AND DROWSINESS. 141 The State of Droiosiness. 23. A very distinct mode of sensibility, which may be properly included under the present head, although adverted to also in a different connexion, is the state named Drowsiness. Allusion has been made to this state in connexion with slow movements (p. 88), and also with the agreeable sensation of muscular rest from ordinary fatigue (p. 11-5). Notwithstand- ing these alliances, the drow^sy condition possesses a standing of its own, and enters, to a considerable degree, into the stream of organic pleasure. We are so far fortunate in not passing instantaneously from an active condition of body into the full unconsciousness of sleep. Both preceding and fol- lowing the perfect state so denominated, there is an interval greater or less, of agreeable, massive sensibility, which in its own character has to be reckoned among the gratifying moments of our existence. Although developed in all its characteristic fulness in proximity to actual sleep, it recurs in slighter degrees in the cycle of our waking moments, and plays a part in the control of our active states, lending itself to the suspension of activity, sometimes as a whole- some corrective, and, at other times, as pandering to indo- lence. It is a curious and not unimportant question whether, as suggested, it be a phase of the Sensibility of Muscle, or whether it is related more intimately to the nerve substance itself. Psychically, we can solve this doubt only by our consciousness of its agreements with recognised nervous modes of sensibility. It is, notoriously, a reaction and a remedy in the case of nervous strain, quite as much as in the strain of muscle. AVhen the nerves are rmi down by a course of functional exercise (if not excessive), their repose easily passes into the drowsy condition, and it may not be incorrect to call it more specifically one of the modes of nerve giving sensibility. The evidences for such an assump- tion are furnished by what is known of the procuring causes, as well as of the obstacles, in the inducing of sleep. Besides 142 SENSATIONS OF ORGANIC LIFE. the fact of periodicity, it is known what are the favouring circumstances of sleep and the reverse. A state the opposite of pleasurable is that when drowsi- ness has supervened, and yet when the natural tendency to perfect sleep is arrested or checked. This is a massive form of painful irritation, whether located in the muscles or in the neryes, and shows the characteristic phase of the sleepy condition, as we shall see again, when we reach the treat- ment of the Appetites. Feverislmess. 24. What is termed feverishness is the extreme and exag- gerated form of so-called excitement. Indeed, the proper meaning of the term excitement, apart from either pleasure or pain, is best put in evidence by the consideration of this state. Nervousness is a familiar designation for too great excita- bility of the nerves, under which they fail to recover their proper tone, or to subside into quiescence and repose, when the necessity for their exertion has passed away. What is termed insomnia means the reluctance of the nervous tissue to assume the phase of somnolence at the periods when sleep properly falls due. In such a condition, thought is more or less awake ; being no longer under voluntary control. The painful character of the state is, in part, connected with the circumstance that the forced thinking is maintained, while the ideas themselves may be painful, or, even if not painful intrinsically, are made so in consequence of the jaded condition of the nerves, under which pleasure is no longer possible. It is the exaggerated persistence of the condition of nervous weariness after too much pleasure with which we are familiar in our proj)er w^aking hours. There is a form of feverishness that is unnaturally plea- surable, — like the action of stimulants in an intense degree. Such a state is on the way to delirium, during which the healthy conditions of the nerves are perverted or rendered abnormal. THE ELECTRIC SHOCK. 143 Feelings of Electrical States. 25. We shall touch upon only one other class of feelings before passing from this subject, — the feelings arising from Electric and Magnetic agencies. It is very difficult to say anything precise on this class of sensations, but their interest is such that we ought not to pass them unnoticed. The electric shock from a Leyden jar is, perhaps, the simplest of all the electric effects ; yet, we are not able to describe the change that it produces on the tissues affected by it. AVhen very severe, it destroys life. The stroke of lightning is proved to be of the same nature. The peculiar feeling of this kind of electricity has its main character from the suddenness of the action ; the painful effect is described as a shock or a blow. When pretty smart, it leaves an unpleasant impression behind, such as to render us averse to a repetition of the experiment. There can be no doubt of the disorganising tendency of the influence when at all severe. The Voltaic shock is very different, in consequence of the altered character of the discharge ; an incessant current being substituted for an instantaneous shock. Still, the painful character remains. The first contact causes a slight blow like the other ; then succeeds a feeling of heat, and a creeping sensation of the flesh as if it were unnaturally wrenched or torn, which after a time becomes intolerable. The peculiar distorting sensation is carried to the utmost in Faraday's Magnetic- Electric Machine, where the current, instead of continuing of one character, is changed from negative to positive, and from positive to negative, a great many times every second. The quality of the pain from this machine may be described as agonising. Yet, feebler discharges of this kind are employed as an electric stimulus in certain diseases. There seems to be a power in electricity to revive the action of torpid nerves ; and, after experience both of common and of voltaic electricity for the purpose, Faraday's invention has been adopted in preference to either. It is now a common application of electricity to try its effects 144 SENSATIONS OF ORGAXIC LIFE. upon the senses one and all. In the more mechanical sense of touch, it simulates some of the usual sensations of the skin. If applied to taste, a mixed gustatory sensation is said to be produced ; in the back of the tongue, which is the region of bitter taste, bitterness is produced, and, at the tip of the tongue, sweetness. 26. The electricity of the Atmosphere is believed to be the cause of quite other sensations than the shock of the thunderbolt. In some states, this influence is supposed to kindle a genial glow in the human frame, while, in other states, the effect is painful and depressing. Many persons complain of a disturbed irritated condition of body on the eve of a thunderstorm. The highly electrified state of the atmosphere in dry cold is generally considered as bracing ; while part of the depression of moist sultry weather is attributed to the absence of electricity. Much, however, remains to be proved in regard to these popular beliefs. The time of greatest effect on the human sensibility from this class of influences is the eve of an earthquake or volcanic eruption ; in which case it is known that the earth's magnet- ism suffers violent disturbances. On these occasions, feelings of depression amounting to nausea and sickness overtake both men and animals, as if some great stimulus of a sup- porting kind were suddenly withdrawn. * Gonchidinq Observations . 27. "We have now described the principal states of feel- ing that enter into the general conditions called physical Comfort and Discomfort. Of all the elements that deter- mine our flowing stream of pleasurable and painful conscious- ness, the foremost, the ever-present, the largest in amount is made up of the series of elements now detailed. Muscular feelings in their wide compass, sensations of digestion, of respiration, of circulation, and nervous states referable to organic conditions of the nerve substance, fill up every day * This is admirably brought out in Bulwer Lytton's Last Days of Pompeii. DAILY STREAM OP ORGANIC FEELINGS. 145 with a volume of sensibility, of fluctuating and varying degree, not only vast in itself, but largely determining the precise efficacy and tone of the other numerous sources of our hedonic condition. We can easily figure to ourselves a few various types of our successive waking states, pleasurable, painful, or neutral, in which these different streams of sen- sibility occupy positions. It may be owing to a speciality of temperament, that some one of these preponderates. Thus our muscular expenditure in its numerous forms — in action, in fatigue, in repose with recuperation — might take the lead ; the undulations of these different conditions reveal- ing themselves to consciousness as the day went on. Or again, the Digestive phases might assert their predominance — a not uncommon type, — easily traceable and assignable by our self-observation. Respiration, however important as an interest, would not bulk so largely in ordinary circumstances. As a matter of course, the conditions of the Nerve Substance would assert themselves, although less easy to separate from the influence of the other great interests. In circum- stances that kept the influence of the outer world at a low figure, while not stirring up powerful emotions or stimulat- ing currents of thought, the organic stream would be the prominent factor in the continuous mental tone. Submerged or overpowered at intervals by the other great interests of our being, it would have its periods of abeyance and disap- pearance from consciousness. For one thing, the objective attitude of pursuit would effectually curb and restrain its pre- dominance ; while, as objectivity itself is necessarily tran- sient, there would still be times of entire recovery of organic consciousness. The same remark would be applicable to the wide-ranging influence of the five senses, whose emotional sensibility co-operates largely with their properly intellectual agency. So also with the wakenings of ideas or thought,— as Memory, Imagination, and Ratiocination, — which both evoke subjectivity and make up the object states that place feeling in abeyance. Moreover, the great emotions standing outside of the strict organic circle have occasions of assert- 10 146 SENSE OF TASTE. ing themselves in such force as to throw everything else into the background. All such influences would be formidable rivals, but still only rivals, to the great streams of sensibility now passed in review ; the rivalry being conducted on equal terms, if not equivalent in amount. It must further be noted that the organic sensibility is the one mode that is always with us, even when overlaid or suppressed by these other ingredients of consciousness. It begins our waking day, and holds us until other elements have had time to enter the field ; being ready to reassert itself as these other elements retire or lose their efficacy. What is still more notable, they constitute the ground tone of our menttil being ; in which capacity they exercise a power of admitting or refusing, or welcoming, or discouraging the operating influences on the stream of pleasure or pain. If the new claimant be adverse to the power in possession, it has to maintain a fight until it succeeds by the right of the stronger ; if, on the contrary, a concurring or harmonising influence, it is accepted with alacrity, and augmented in efficacy to produce its proper results. This is a power that, from the very nature of the case, distinguishes the strong organic manifestations of such organs as have been enumer- ated ; whence the common observation as to the preference to be given to the strictly corporeal side of our being in all our calculations of future weal or woe. .**/ SENSE OF TASTE. / This is a peculiar sense attached to the entrance of the alimentary canal, as an additional help in discriminating what is proper to be taken as food, and an additional source of enjoyment in connexion with the act of eating. 1. The substances used as food are more completely dis- tinguished by the taste than by the digestion. The tastes of bodies are almost as widely different as is their chemical composition ; but, in order to have taste, a substance must be either liquid or soluble in the mouth. The bodies acting on the sense of Taste are innumerable. SAPID SUBSTANCES. 147 They are found in the mineral, vegetable, and animal king- doms ; and many of them may be discriminated by means of this property. Of mineral bodies, water and the elements of atmospheric air are remarkable for having no taste. But most other liquids and gases, and a very great proportion of solid sub- stances, if capable of being dissolved by the saliva, have a distinct action on the palate. All acids, all alkalies, and nearly all soluble salts are sapid. It is remarked that, in salts, the taste is determined more by the base than by the acid. Thus, salts of iron have in general the inky taste ; salts of magnesia partake, more or less, of the well-known character of Epsom salts. There is, also, something of a common character in the salts of silver, of soda, of potash, of ammonia. It is a curious fact, that the chemical combination M- 0•^ or two atoms of a metal with three of oxygen (termed sesqui- oxides), causes sweetness. Alumina is an illustration; for alum is known to be sweet as well as astringent. The oxide of chromium is still sweeter. Glucina is the sweetest of all, and has its name from this quality. The salt of silver, termed hypo-sulphite, and its com- binations with hypo-sulphites of the alkalies, are among the sweetest bodies known. The salts of lime are bitter. The organic alkalies are all intensely bitter ; quinine, morphine, strychnine, are instances. Strychnine when diluted with water, to the degree of one in a million, has still an appreciable taste. There is a certain class of vegetable compounds — neutral bodies, which are at present characterised as the bitter and extractive principles of plants. I quote a few examples from the list given in Gregory's Orgajiic Chemistry , p. 457. Gentianine, from Gentiana liitea, forms yellow needles, very bitter. Ahsinthine, from Artemisia ahsintheum, or wormwood, is a semi-crystalline mass, very bitter, soluble in alcohol. Tanacetine, from tanacetum viilgare, is very similar 148 SENSE OF TASTE. to it. Syringine is the bitter principle of the lilac, syringa vulgaris. Colocynthine, the active principle of colocynth, is amorphous, intensely bitter and purgative. Quassine is a yellow, crystalline, and very bitter substance, from the wood of quassia amara. Lupuline is the bitter principle of hops. Liminine, or Limine, is a bitter, crystalline matter, found in the seeds of oranges, lemons, etc. AYith regard to vegetable and animal substances in general, Gmelin remarks : ' Some organic compounds, as gum, starch, woody fibre, white of egg, etc., have no taste ; others have a sour taste (most acids) ; or a rough taste (tannin) ; or sweet (sugar, glycerine, glycocol) ; or bitter (bitter principles, narcotic substances, and many acrid sub- stances, also many resins) ; or acrid (acrid oils and camphors, acrid resins, acrid alkaloids) ; or fiery (alcoholic liquids, volatile oils, camphors)' {Chemistry, vol. vii. p. 66). Not only are the different classes of vegetable and animal products distinguished by their taste, as apples from apricots, wine from cider, flesh from fat, but in every such class there are many distinguishable varieties. The class of wines, based on the common ingredient, alcohol, spreads out into innumerable kinds fi'om the presence of sapid substances in quantity so small as to elude the search of the chemist. It is shown by this and by many other facts, that an extremely minute portion of a sapid substance may make itself acutely felt to the taste. The bitter element of soot, for example, can be distinguished in cookery to a very high degree of dilution. Acids and bitters are said to be the most readily detected of all sapid substances ; then saline, and, lastly, saccharine. It has been found that one part of sulphuric acid in 10,000 of water, and one of sulphate of quinine in 33,000 of water, can be detected, when the solution is carefully compared with pure water. Sugar cannot be tasted when there is less than one in 80 or 90 of water ; and, of common salt, one part is necessary to 200 of water (Marshall's Physiology, i. 481). 2. The organ of Taste is the tongue ; and the seat of sen- sibility is the mucous membrane covering its surface. THE TONGUE. 149 ' The upper surface of the tongue is covered all over with numerous projections, or eminences, named j^apiUcB. They are found also upon the tip and free borders, where however they gradually become smaller, and disappear towards its under surface.' These papillge are distinguished into three orders, varying both in size and in form. ' The large papillse, eight to fifteen in number, are found on the back part of the tongue, arranged in two rows, which run obliquely backwards and inwards, and meet towards the foramen caecum, like the arms of the letter V.' ' Tlie middle- sized papillae, more numerous than the last, are little rounded eminences scattered over the middle and fore part of the dorsum of the tongue ; but they are found in greater numbers and closer together, near and upon the apex.' ' The smallest papillae are the most numerous of all. They are minute, conical, tapering, or cylindrical processes, which are densely packed over the greater part of the dorsum of the tongue, towards the base of which they graduall}' disappear. They are arranged in lines, which correspond at first with the oblique direction of the two ridges of the large papillae, but gradually become transverse towards the tip of the tongue.' ' These different kinds of papillae are highly vascular and sensitive prolongations of the mucous membrane of the tongue. When injected, they seem to consist almost entirely of capillary vessels ; the large papillae, containing many vas- cular loops, whilst the smallest papillae are penetrated by only a single loop. Nerves proceed in abundance to those parts of the tongue which are covered with papillae, into which the nerve tubes penetrate.' ' The papillae are un- doubtedly the parts chiefly concerned in the special sense of taste; but they also possess, in a very acute degree, common tactile sensibility' (Quain). The nerves supphed to the tongue are the glosso-pharyngeal on the back part, and t\\-igs of the fifth pair on the fore part. The former must be considered as, in all probability, the nerve of taste proper. The fifth pair, being a nerve of touch, can confer that high tactile sensibility distinguishing the tip of the tongue ; 150 SENSE OF TASTE. but there are no facts decisively showing any portion of this nerve to be the medium of pure taste. It is true that some so-called tastes, as the sour or acid, can be discerned by the tip ; but these are properly of the nature of pungent or fiery stimulation, capable of acting on nerves of touch. A bitter taste, which appeals to the strict gustatory sensibility, is felt principally in the back part of the tongue. Fiery, coohng and astringent tastes may arise through the lips and the gums, showing that they are merely effects on our common or tactile sensibility. Mustard acts on any tactile surface with variations of degree merely. It has not been possible to excite a pure gustatory sensation by irritating the fifth pair of nerves. Notwithstanding the apparent simplicity and consistency of referring the purely gustatory sensations to the glosso-pharyngeal nerve, and the sensations that are more nearly allied to tactile pungency to the nerves of the fifth pair, the preciseness of the allocation does not seem to be fully borne out by physiology. According to Professor Michael Foster {Physioloijy, p. 1398), the nerve fibres of the fifth nerve take part with the others in giving birth to the proper gustatory sensations. This must be so, if it be the case, as affirmed, that, while bitter tastes are located in the back part of the tongue, sweetness is felt at the tip, or in the localities supplied chiefly from the fifth pair and giving birth to acid, alkaline, saline and astringent tastes. ' We conclude generally,' say Messrs. Todd and Bowman, ' with regard to the tongue, that the whole dorsal, or upper sur- face, possesses taste, but especially the circumferential parts — viz., the base, sides and apex. These latter regions are most favour- ably situated for testing the sapid qualities of the food; while they are much less exposed than the central part to the pressure and friction occasioned by the muscles of the tongue during mastication. The central region, as a whole, is more strongly protected by its dense epithelium, and is rougher, to aid in the connninution and dispersion of the food.' But, in addition to the tongue, ' the soft palate and its arches, with the surface of the tonsils, appear to be endowed with taste in various degrees in different individuals ' (i. 443). 3. The increasing sensibility of the tongue, from tip to ])ack, serves as an inducement to move the food gradually THREEFOLD SENSIBILITY OF THE TONGUE. 151 onward in the direction of the pharynx, in order to be finally swallowed. The same sensibility, actinoj according to the general law of feeling-guided action, or volition, keeps up the mastication, whereby the sapid action of the food is increased by solution and comminution of parts. Thus it is that mastication is purely a voluntary act, while deglutition or swallowing is purely reflex or involuntary. Among the conditions of taste, in addition to solubility, it is noticed that ' taste, like touch, is much influenced by the extent of surface acted on ; and is also heightened by the motion and moderate pressure of the substance on the gustatory membrane'. In order to taste, also, the tongue must not be in a dry or a parched condition. ' The impres- sion of cold air deadens the sense of taste.' * 4. The precise mode of action whereby the nerves of the tongue are stimulated has not as yet been explained. Taste may be produced by mechanical irritation of the surface, as by a smart tap with the fingers on the tip of the tongue, and by galvanism. A stream of cold air directed upon the tongue gives a cool saline taste, like saltpetre. If we look at the substances that cause taste proper, it appears probable that their cheinical constitution is the determining circumstance ; whence it would seem that the action is a chemical one. A certain secretion from the blood-vessels that line the papillae * Another conditiou of taste, brought to light by the researches of Graham on ' Dialysis,' is, that the substance should belong to the crystalloid class of bodies, and not to the colloid class. The colloids are represented by starch, the gums, caramel, tannin, albumen, gelatine, vegetable and animal extrac- tive matters. Now, it is a lav? that these colloids do not penetrate one another, except with slowness and difficulty : whereas a crystalloid body, like sugar or salt, penetrates a colloid very readily. Animal membranes belong to the colloid class, and, accordingly, while they are freely permeated by crystalloid substances, they resist the passage of starch, gum, albumen, gelatine, etc. This would be a sufficient reason for the absence of taste in these bodies. Graham remarks : ' While soluble crystalloids are always higlily sapid, soluble colloids are singularly insipid. It may be questioned whether a colloid, when asted, ever reaches the sentient extremities of the nerves of the palate, as the latter are probably protected by a colloidal membrane, impermeable to soluble substances of the same physical constitution.' 152 SENSE OF TASTE. of the tongue combines with the dissolved food, and the act of combination constitutes the stimulus of the nerve fibres. We know that a chemical action on any surface or tissue will suffice to stimulate a nerve and produce sensation ; and it is difficult to assign any other mode of stimulus either in taste or in smell. 5. The external objects of the sense, and the structure of the organ having thus been considered, it remains for us to de- scribe the mental phenomena, — that is, the Sensations them- selves. From what has been already said, the reader will gather, if he has not otherwise remarked it, that the tongue is the seat of a twofold sensibility — taste and touch. I go still farther, and ascribe to it a threefold sensibility, — viz., touch, taste properly and strictly so-called, and relish, or a participation in the alimentary sensations. The reasons are the following: — First, there is an obvious continuity of struc- ture in the tongue and the aUmentary canal, — a common character of surface as regards mucous membrane, glands, and papillae, — which would imply some community of action and feehng, in the midst of diversity. ' We may here allude to a certain gradation that is apparent from the papilla3 of touch, through those of taste, to the absorbing villi of the small intestines. Touch shades into taste, and at a lower point sensibility is lost' (Todd and Bowman, i. 441). Secondly, the tongue, besides its power of discriminating niceties of taste that have very little reference to digestibility, can inform us at once whether a substance will agree or dis- agree with the stomach ; and this it can do only by being, as it were, apart of the stomach, affected, Hke it, by wholesome or unwholesome contacts. Thirdly, the peculiarity we call relish is not the same as a mere taste. For the type of taste, I may take such substances as common salt, quinine, soot, Epsom salts. For relishes, I would select butter and animal flesh ; the savoury in cookery being made up much more of relishes than of tastes. The condition of the stomach governs the one, but not the other. After an attack of sea-sickness, a person is still in a condition to discriminate sour, bitter, RELISHES. 158 alkaline, or acrid, when the choicest food excites no relish in the mouth. Fresh, disgusting, nauseous, are terms applying to the stomachic sensibility and to that portion of the tongue in sympathy with the stomach, and not to tastes as I under- stand them. With this explanation, I shall now proceed to examine in detail the sensations of the tongue. 6. Deferring for the present the consideration of the purely tactile sensibility, shared by the tongue in common with the skin and the inner surface of the mouth, we shall have to classify and describe the several kinds of sensations coming under both Taste and Relish. On the general plan of taking the least intellectual sensations first, we should commence with the relishes and disgusts of taste, which constitute its relation with the alimentary sensations already treated of. But these feelings need not be again gone into, in the detail ; all that appears necessary is to quote a few instances, with the view of illustrating still further the distinctions we have drawn, between the alimentary sensa- tions of the stomach and those of the mouth, and between both and the proper sensations of taste. 7. The classification will therefore commence (I.) with Belishes. These are the agreeable feelings arising from the stimulus of food on the organs of mastication and deglutition. They are intense in degree. The substances that produce them in greatest amount are reckoned savoury by pre-eminence. Animal food has the highest power of exciting a vigorous relish, or that keen sensation so powerful as a stimulus to mastication and the taking of food, rendering the individual voracious for the time being. A health}' digestion and the state of hunger are the necessary conditions of a strong relish, whether in the stomach or in the mouth; from which fact, as already said, we can discern the difi^erence there is between a mere taste and a relish. Butter and oils and fatty substances are relishes, — used for that purpose along with the more in- sipid kinds of food, such as bread. Sugar is both a taste and a relish. Inasmuch as it is one of the necessaries of animal life — which is proved by the function of the saliva in pro- 154 SENSE OF TASTE. duciijo it from starchy substances, — there is a direct craving- for it throughout the system ; and everything craved for in this way is hkely to produce a far deeper impression than a mere sensation of taste. The rehsh in the mouth is much more intense or acute than the feehng in the stomach ; although this last may be more influential upon the general tone of the system, by its amount. That the two interests are not altogether identical is shown by the circumstance that many tongue-relishes accompany difficult digestion. But I am not aware of any case where what passes in the mouth is found nauseous to the digestion ; so far the two senses would seem to be in accord. 8. Relishes imply their opposite, Disgusts. This sensation IS inspired by certain substances as part of their nature. At particular times, it may arise from any contact whatever, — the alimentary surface being in a state of distemper. Oily sub- stances, when cold and solid, are relishes ; but, when hot and liquid, readily disagree with the palate. Repletion renders any kind of food distasteful, and some kinds absolutely nauseous. In every point of view, this feeling is as much dependent on the condition of the alimentary canal as on the material tasted. The different degrees of relish and nausea exhaust all that part of taste in sympathy with digestion ; what follows, next in order, belongs (U.) to tlie distinctive sensibility of the tongue. 9. Siveet tastes. At the head of these, we must place the sugary taste, as being the most prevalent of all forms of sweetness. The sweetness of every kind of fruit, of bread,, of milk, of alcoholic liquors, and of confectionery in general, is known to arise from sugar. Besides giving relish, it acts strongly upon the sense of taste proper ; but no pleasure of mere taste can be compared in amount and influence to an agreeable alimentary feeling. We can lay it down as a rule, that the pleasures of taste proper have, as a whole, a less in- fluential action than the other class ; and this must serve as a SWEET AND BITTER TASTES. 155 defining circumstance for every individual of them. The feeling of a sweet taste is acute, but does not inspire the energy of volition that follows up a savoury morsel. When digestion is satisfied, there remains the enjojanent of sweets ; and when the taste for these becomes cloyed by repetition, it is by an independent effect on the gustatory nerves.* But the great distinction of this feeling, and of all other feelings of taste proper, relates to the intellect, or to the power of discrimination belonging to this organ ; whereby an indefinite number of substances can produce impressions recognised by us as totally different from each other in character, — which impressions of difference can remain or be recalled, after the original is gone, to compare with new cases that may arise, and to give that sense of agreement or disagree- ment whereon all our knowledge of the world is based. In the case of sweetness, for example, not only can we be affected with the pleasurable feeling or emotion belonging to it, but we can be distinctively affected by a great many substances possessing the quality : we can identify some, and feel a want of identity in others ; and we can so far retain the impression of a taste of yesterday as to compare it with a taste of to-day. This feature distinguishes the feehngs of the mouth from organic feelings whose more usual form is general sensibility ; it distinguishes, in some degree, tastes from relishes, although these last are also discriminated to a considerable extent ; and it is the point of superiority which sight, hearing, and touch, have, to a still greater degree, over organic sensations. 10. Bitter tastes. These are exemplified by quinine, gentian, or bitter aloes. This, and not sourness, is the proper contrast of sweet. As sweetness is the pleasure proper to taste, so bitterness is the peculiar or distinctive form of pain inflicted through this sense. Without having the bulk and influence of the massive forms of pain, this sensation is highly intense in its own limited region, ex- * For an analysis of tastes and relishes in relation to digestion, see the account of a ' Corporation dinner ' in Dr. Lauder Bruuton's Disorders of Digestion. 156 SENSE OF TASTE. pressing itself by wryness and contortion of the features. The sweet and the bitter represent the two characteristic modes of acting on the pure gustatory nerves. They are distinct from rehsh on the one hand — which involves sym- pathies with the stomach — and from the modes of tactile sensibility on the other. 11. The classes that remain involve (III.), in a greater or a less degree, the nerves of touch. Saline tastes. Common salt may be taken as an example of this class. Mineral waters, containing salts of soda, mag- nesia, and lime, have a saline taste. This taste is rarely an agreeable one, in many cases it is very disagreeable ; but we should be disposed to describe the feeling, in most instances, as singular and characteristic rather than as either pleasing or the reverse. Of it, as of all that follow, the character is best expressed by saying, that it can be discriminated from every other. The repulsive taste of Epsom salts would be termed a compound of the saline and the bitter. It2. The alkaline taste is usually more energetic than the saline, as might be expected, seeing that a salt is a neutralised alkali. But if the remark above made be correct, — namely, that salts owe their taste principally to their base, — the alkali ought to have a considerable share of the saline in taste. Most mineral alkalies, and some earths and oxides of metals, have characteristic tastes, rarely agreeable, and often not markedly disagreeable. 13. The sou?' or acid taste is much more uniform in its nature than either the saline or the alkaline ; which we may fairly ascribe to the influence of the acid quality itself, irre- spective of the constituent elements. This is a sharp, pene- trating, pungent action, having, when very powerful, the pain, more of a burn, than of a repulsive taste. In diluted forms it is an agreeable pungent stimulus to the mouth : hence the liking for vinegar (the sour of cookery, as sugar is the sweet), and for acid fruits and vegetables. A galvanic current in the mouth causes sourness. ASTRINGENT AND FIERY TASTES. 157 Professor Foster proposed to designate a class of tastes by the title ' metallic '. As no metal in purity can act on the mouth, in consequence of want of solubility in the fluid of the tongue, it is only in some form of combination that metals can affect our gustatory sensibility. In other words, they must be transformed into acids, alkalies, or salts, so that they may acquire solubility, and thereby act upon the nerves of taste. In this way, the metallic becomes merged in one or other of the groups above assigned. 14. The astringent is a distinct form of the sensation of taste. As an example, we may refer to the effect of alum in the mouth. It is evident, hov^ever, that, in the acid action, and still more in the action of astringency, vv^e depart farther and farther from the proper feeling of taste. Astringent substances act on the skin and on the mucous membranes generally ; and the influence lies in a kind of contraction or forcible shrinking of the part, to which we are sensitive whenever it occurs as a touch. The 'rough taste of tannin' may be put down under astringency. 15. The fiery taste of alcoholic liquors, mustard, pepper, camphors, and volatile oils, given in Gmelin's classification, seems to me to be happily designated. I am inclined to think that this too is more a tactile action than a gustative, although, in some of the other substances entering with alcohol into wines, spirits, and malt liquors, there is a genuine stimulus of the taste. The acrid taste may be looked on as a form of the fiery, or astringent, combined with some ingredient of the bitter. On the other hand, the effect of peppermint resembles a cold contact on the skin. The pungency that marks all this class of sensations is a remarkable state of feeling, deserving to be once for all discussed at length. This discussion, however, I prefer to take up under the sense of smell, the next in order in our arrangement. 1(3. With regard to the Intellectual aspect of Tastes in general, Longet observes that these sensations are deficient as regards the power of being remembered ; and he gives as 158 SENSE OF SMELL. a proof the fact that, when we dream of being present at a repast, we see the viands but do not taste them. The fact is not beyond question, and, besides, it is an extreme com- parison : it contrasts the most intellectual of all the senses, the most abiding of all sensations, with those that are least so. It is thus far true, that we do not recover sensations of taste so as to live habitually on the ideas of them ; but they are slightly recoverable even as ideas, and, for the purposes of identification and contrast, they may be recovered to a very great extent. A wine tasted to-day can be pronounced the same or not the same as a wine tasted a week ago, while well-marked tastes may be remembered for years in this way. The intellectual character of the sense is also illustrated by its improvability. A wine-taster, a cook, or a chemist, can acquire a delicate sensibility to differences of taste, implying that its impressions can find an abiding place in the memory. SENSE OF SMELL. his sense is in close proximity to the organ of Taste, wifh which smell frequently co-operates ; but we may con- sider it as placed at the entrance of the lungs to test the purity of the air we breathe. 1. The external objects of Smell — the material substances whose contact produces the sensations, are very numerous. They require to be in the gaseous state, in the same way that the objects of taste require to be liquefied. Solids and liquids, therefore, have no smell except by being evaporated or volatilised. The greater number of gases and vapours are odorous. Of inodorous gases, the principal are the elements of the atmosphere, — that is to say, nitrogen, oxygen, vapour of water or steam, and carbonic acid.* In the long list of * With regard to carbonic acid, the assertion as to the absence of smell is true of the amount present in the atmosphere ; but, collected in mass, this gas has a slightly pungent, somewhat acid odour. As with pungent odours generally, the effect is probably due to the irritation of the nerves of the fifth pair, and not to the proper olfactory sensibility. EXTERNAL OBJECTS OF SMELL. 10'.) gaseous bodies recognised by the chemist, we find very generally some action on the nostrils, — carbonic oxide, sul- phurous acid, chlorine, iodine, the nitrous gases, ammonia, sulphuretted and phosphoretted hydrogen, etc., the vapour of muriatic, nitric, and other acids. The singular substance ozone, produced occasionally in the atmosphere, is named from its smell, which is the smell of sulphur, and of the odour given forth by electricity. Some of the metals and solid minerals give out an odour, — as, for example, the garlic smell of arsenic, and the odour of a piece of quartz when broken. The effluvia of the vegetable kingdom are countless. Besides such widely spread products as alcohol and the ethers, a vast number of plants have characteristic odours, usually attaching to their flowers. The animal kingdom, also, fur- nishes a variety of odours ; some general, as the ' scent of blood,' and others special, as musk, the flavour of the cow, the sheep, the pig. ' All volatile organic compounds,' says Gmelin, ' are odoriferous, and most of them are distinguished by very strong odours ; e.g., volatile acids, volatile oils, camphors or stearoptenes, and alcoholic liquids ; marsh gas (carburetted hydrogen), and olefiant gas, have but very little odour.' The pleasant odours, chemically considered, are hydro- carbons ; that is, they are composed chiefly of hydrogen and carbon. Such is alcohol and the ethers, eau de Cologne, attar of roses, and the perfumes. Many smells, however, elude investigation from the minuteness of the substance causing them. Thus the vinous flavour is due to a substance which the chemist has been able to separate, being termed the oenanthic ether ; but the bouquet of individual wines has not been laid hold of. The repulsive gmd disagreeable odours very frequently contain sulphur. Sulphuretted hydrogen is one of the most common of the disgusting class. The worst smelling substances as yet discovered have arsenic for their base, as will be seen from the following extract (Gregory's Chemistry, p. 382). 160 SENSE OF SMELL. ' When acetate of potash is heated aloiig with arsenious acid, a very remarkable hquid is obtained, which is the oxide of a new radical. This hquid, which is spontaneously inflammable, and has a most offensive alliaceous smell, has long been known in an impure state, under the names of liquor of Cadet, and alcarsine. Bunsen, by a long series of the most profound and persevering researches, established its true character as the oxide of the radical kaJcodyle.' This radical, when obtained, ' is a clear liquid, refracting light strongly. When cooled, it crystallises in large square prisms, and acquires, when pure, the appearance of ice. Its smell is insupportably offensive, and its vapour is highly poisonous. The two latter characters belong to all the compounds of kakodyle, with hardly an exception.' Protoxide of kakodyle, the chief ingredient in the liquor of Cadet, is most offensive to the smell, and very nauseous to the taste. ' Chloride of kakodyle is a volatile, horribly fetid liquid, the vapour of which attacks strongly the lining membrane of the nose, and provokes a flow of tears.' The pungent odours have ammonia for their type. The volatile alkali, nicotine — the element of the snuffs, is an instance. In smelling salts, ammonia is the substance given forth. Liebig has been able to lay hold of, and isolate, the sub- stance that gives the odour of roast meat. Burning fat gives forth odours that exemplify the volatile oils specified by Gmelin. 2. The development or production of odours is favoured by a variety of circumstances. Heat, by its volatilising power, and by promoting decomposition, is the most power- ful agent. Light, also, which carries forward the develop- ment of the plant, is an odoriferous influence. Hence the abundance and variety of odours in warm and sunny climates, and in the summer season. The presence of moisture is often favourable ; but the manner in which this agency acts is not always obvious. It may, perhaps, dissolve solid matters, and so put them in the way of being DIFFUSION OF ODOURS. 161 volatilized : this may be the cause of the evolution of per- fumes after a shower. On the other hand, some flowers are most odorous when dried. Friction is a source of odours. By rubbing two pieces of flint or siliceous rock, a smell is given forth ; sulphur, treated in the same way, has a smell. Many of the metals have the same property. Doubtless, some ingredient is volatilized by the rubbing action. 8. The diffusion of odours is an interesting point, and has been cleared up by the researches of Professor Graham. Some odours are light, and, therefore, diffuse rapidly and rise high ; as, for example, sulphuretted hydrogen. Such is, evidently, the character of the aromatic and spice odours : they, by their intensity and diffusibility combined, are smelt at great distances. The Spice Islands of the Indian Archi- pelago are recognized far out at sea. It happens, however, that the sweet odours are remarkably persistent, while the sulphuretted compounds, which are among the most nauseous, are very rapidly destroyed in the atmosphere. The animal effluvia (excepting sulphuretted hydrogen) are dense gases, and are diftused slowly. They do not rise high in the air. In scenting, a pointer keeps his nose close to the ground. The unwholesome effluvia of the decaying matter laid on the soil is avoided by getting to a moderate height : a person lying will smell what would not be smelt b}^ one standing. The danger of sleeping on the ground in tropical swamps is a matter of fatal experience ; swung in a tree fifty feet high, one may pass the night safely. Here diffusibility is one, although not the only, circumstance ; during the night, the ventilation or upward current from the ground is arrested, and the malaria, being little ditt'usible or buoyant, settles on the surface. 4. We have next to consider the organ of smell, — that is, the Kose. ' This organ consists of, first, the anterior prominent part, composed of bone and cartilage, with muscles which slightly move the latter, and two orifices opening downwards ; and secondly, of the two nasal fossse. in which the olfactory nerves are expanded. The narrow cavities last mentioned are 11 162 SENSE OF SMELL. separated one from the other by a partition (the septum of the nose) formed of bone and cartilage ; they communicate at the outer sides with hollows in the neighbouring bones, and they open backwards -into the pharynx through the posterior nares,' or openings. The sensitive surface is a membrane lining the whole of the interior complicated cavities, called the pituitary or Schneiderian membrane. The tortuosity of the passages of the nose gives extent of surface to this mem- brane, and thereby increases the sensibility of the nose as a whole. I shall quote part of the anatomical description of this sensitive tissue. ' The cavities of the nose are lined bv a mucous membrane of peculiar structure, which, like the membrane that lines the cavity of the tympanum, is almost inseparably united with the periosteum and perichondrium, over which it lies. It belongs, therefore, to the class of fibro- mucous membranes, and it is highly vascular. Named the pituitary membrane, it is continuous with the skin, through the anterior openings of the nose ; with the mucous membrane of the pharynx, through the posterior apertures of the nasal fossae ; with the conjunctiva (of the eye), through the nasal duct and lachrymal canals ; and with the lining membrane of the several sinuses (hollows) which communicate with the nasal fossae. The pituitary membrane, however, varies much in thickness, vascularity, and general appearance in these different parts,' With regard, also, to the distribution of the olfactory nerve in the membrane, there are great differences in the parts, the general fact being that the distribution is most copious in the interior parts of the cavity or those farthest removed from the outer openings. The parts near the openings are supplied with nerves from the fifth pair, which give to these parts a tactile sensibility, excited by pungent odours, and by cold. The olfactory nerve is the most conspicuous of the nerves of sense ; it passes inward to a special ganglion, called the olfactory ganglion, which is a prominent object in the brain of all the vertebrate animals, and, in the lower orders, stands forth as a distinct lobe, or division, of the encephalon. ACTION OF ODOURS ON THE NOSE. 163 The sense of smell seems to play a far more important part in the Uves of the lower animals than it does in our own life ; and what we now possess is probably the mere remnant of a once powerful mechanism. We may, perhaps, connect with this, on the one hand, the fact that, even in ourselves, the olfactory fibres have allotted to them what is virtually a w^hole segment of the brain, namely, the olfactory lobe, and, on the other hand, the fact that olfactory sensations seem to have an unusually direct path to the inner working of the central nervous system. Mental associations cluster more strongly round sensations of smell than round almost any other impressions we receive from without. And powerful reflex effects are very frequent, many people faint- ing in consequence of the contact of a few odorous particles with their olfactory cells (Foster, A Text-book of Physiology, 5th ed., p. 1390). 5. The action of odours on the membrane of the nose has next to be considered. On this subject, as on the action of sapid substances on the tongue, much remains to be knov^n. Nevertheless, there are some interesting facts which show^ that the action is of a chemical nature, or, at least, depends upon chemical conditions. For the following statements, I am indebted to Professor Graham. Odorous substances in general are such as can be readily acted on by oxygen. For example, sulphuretted hydrogen, one of the most intense of odours, is rapidly decomposed in the air by the action of the oxygen of the atmosphere. In like manner, the hydro-carbons, above alluded to as odorous, are all oxidizable, — the ethers, alcohol, and the essential oils that make the aromatic perfumes. The gases that have no smell are not acted on by oxygen at common temperatures. The marsh gas, carburretted hydrogen, is a remarkable case in point. This gas has no smell. As a proof of the absence of the oxidizable property. Professor Graham obtained a quantity of the gas, from the deep mines where it had lain for geological ages, and found it actually mixed up with free oxygen, which would not have been possible if there had been the smallest tendency for the tw-o to combine. Again, 164 SENSE OF SMELL. hydrogen has no smeU, if obtained in the proper circum- stances ; now this gas, although combining with oxygen at a sufficiently high temperature, does not so combine at any temperature endurable by the human tissues. It is, further, determined that, unless a stream of air containing oxygen pass into the cavities of the nostrils, along with the odoriferous effluvia, no smell is produced. Also, if a current of carbonic acid accompany an odour, the effect is arrested. In the third place, certain of the combinations of hydrogen have been actually shown to be decomposed in the act of pro- ducing smell. Thus, when a small quantity of seleniuretted hj^drogen passes through the nose, the metallic selenium is found reduced upon the lining membrane of the cavities. The action on the sense is very strong, notwithstanding the minuteness of the dose ; there is an intensely bad smell, as of decaying cabbage, and the irritation of the membrane causes catarrh. These facts, so far as they go, prove that there is a chemical action at work in smell, and that this action con- sists in the coinbination of the oxygen of the air with the odorous substance. The effect of ozone, which is considered a more active form of oxygen, and, therefore, not oxidizable, may be to decompose the nasal mucus, and so to stimulate the nerve of smell.* 6. AVe pass, now, from the physical to the mental pheno- * The minuteness of the particles of bodies acting on the sense of smell has often been dwelt upon as a striking example of the divisibility of matter. Sulphuretted hydrogen in the atmosphere, in the proportion of one to a million, is distinctly perceptible. Ammonia is perceptible in the proportion of 1 to 33,000. The following minute quantities of different substances spread out on the surface of smell cause a distinct sensation : — of phosphuretted hydrogen, ^^-^ gr. ; of sulphuretted hydrogen, -^^-^-^ gr. ; of Bromine, ^xriffTj g^- ; of oil of resin, xTSTraoinr &■ A still smaller quantity of musk than the last given smells strongly, but the actual measure has not been ascertained (Valentin). Among the instances of powerful and far-reaching odours, we may rank the roasting of meat and many other odours of the kitchen, burning wood and tobacco. CLASSIFICATION OF ODOURS. IGo mena of smell : — the sensations, or peculiar states of con- sciousness, that all those physical antecedents end in giving birth to. Unavoidable allusion has already been made to these mental effects, in the description of the smelling substances. ' Linnaeus has divided odours into seven principal classes : 1st, aromatic, as the carnation, the laurel, etc. ; 2nd, frag ra7it, as the lily, the crocus, the jasmine, etc. ; 3rd, ambrosiac, among M'hich are musk and amber ; 4th, alliaceous, which are agreeable to some persons and disagreeable to others, and have more or less of the character of garlic, — assafoetida, for example, and several other gum-resinous juices; 5th, fetid, a,s those of the goat, of the rag-wort {orchis hirci?ia), valerian, etc. ; 6th, virulent, as those of Indian pink (I'oeillet d'Incle), and many plants of the family of the solaneae (from solanum, the night-shade) ; 7th, nauseous, as the gourd, the cucumber, and those of its class ' (Longet, p. 151). Of several classifications quoted by the same author, the above seems to me the best, but even that one is by no means free from objections. The three first classes — the aromatic, fragrant, and ambrosiac — do not appear to have very stronglv marked differences ; nor is the distinction between fetid and nauseous a generic one. As in describing taste, I shall proceed upon the plan of stating, — first, the odours that owe their character to sym- pathy with the vital organ in alliance with the sense, — namely, the Lmigs ; secondly, those that appeal to the pm-ely Olfactory sensibility ; and, thirdly, those involving an excitation of the nerves of Touch. 7. Fresh odours are such as have an action akin to pure air, or coolness in the midst of excessive heat ; an action mainly respiratory, or tending to increase the activity .of the lungs, and, with that, the physical energy of the system. Many of the balmy odours of the field and the garden have this effect : musk, eau-de-Cologne, and other, but not alJ, perfumes, are included in the same class ; the odour of the cow is both fresh and sweet. We may recognize them by 166 SENSE OF SMELL. their effect in stimulating and reviving the system under the oppression and suffocation of a crowded assembly. Such odours are not always fragrant in their character, for we might cite cases of unpleasant effluvia that seem to refresh and stimulate the system. The odour of a tan-yard is, perhaps, a case in point. The nervous connexions of the nostrils with the lungs enable this reaction of the one upon the other to take place. Or the influence of the gases may be on the surface of the lungs, rather than on the nose — a thing not at all unlikely in many cases coming under both freshness and the opposite. On this supposition, these would be smells falsely so called, and would correspond to the relishes and disgusts described under taste. 8. The opposite of freshness is shown in the close or suf- focating odours. The effluvia of crowds, by acting on the lungs, have pre-eminently this damping and discouraging action on the powers of life ; whence it is that we seek the open air and the solitudes of nature, to shake off the depres- sion of rooms and of cities. The effluvia of warehouses, stores, and mills, where cotton, wool, cloths, etc., are piled up, and where ventilation is defective, are of a like unwholesome description, The smell of a pastrycook's kitchen is sickening. The action of highly-heated iron stoves seems of the same nature ; also, the smell of a woollen screen when held too close to the fire. In these last instances, there is believed to be an evolution of the unwholesome and suffocating gas cyanogen, from the destructive decomposition of the woolly particles floating in the air, or making part of the screen. 9. Although we may not be able to affirm that any class of odours stimulates the stomach by a direct influence, as fresh odours do the lungs, there can be no doubt as to the existence of a class of the opposite kind — the disgusting or nauseous odours. That is to say, there are certain gases, of which sulphuretted hydrogen is an example and a type, that pervert the action of the alimentary canal, as some tastes do. It is doubtful, at least so far as my information goes, on what surface these effluvia operate — whether on the membrane of FRAGRANT ODOURS. 167 the nose exclusively, or (as is probable) partially on it and partially on the mucous surface of the tongue, throat, and stomach. But, whatever be the seat of action, the fact in question is one sufticiently well marked to make the specific difference of a class. 10. It may be a question whether the foregoing classes exemplify true and proper effects on the organ of smell. Xo such ambiguity attaches to the odours that we term sweet or fragrant. These represent the pure or proper pleasures of smell : the enjoyment we are able to derive through the olfactory nerves and ganglion. They include the substances that convey along this channel to the mind a perfectly pleasurable stimulus. The sweetness may accompany fresh- ness, or it may not. The odour of the violet is a pure instance of sweetness : the rose, jasmine, orange, lemon, lavender, rosemary, are well-known examples of odorous plants. The cases of sweetness enjoyed with some other quality are also extremely numerous. Sweetness is a name for a variety of pleasures. Derived originally from taste, it is extended to smells, to sounds, and to several of the higher emotions, such as the tender affections, and the beautiful in nature and in art. These feelings are so far of a kindred nature, as to suggest and support each other. They all agree in being forms of pure passive pleasure. In this respect, they resemble muscular repose, warmth, and healthy digestion ; but they are more acute than these states. They are, also, more intellectual, — as shown both in dis- crimination and in ideal persistence, which gives the superi- ority indicated by the name ' refinement '. 11. The opposite of sweet in odours is described by the general name stinks : the expressive word bitter is not usually applied to smell. The term ' raal-odour " has come into use, and is a convenient word. If we leave out both the nauseous odours, and certain other forms of the disagreeable to be afterwards described, this class will be hmited considerably. Assafoetida may be given as an example of an odour intensely repulsive, by its action on the 168 SENSE OF SMELL. olfactory nerves alone. The cadaverous odour is of the repulsive kind, but it is only one of many forms of disagree- able effluvia arising from animal decay. The aroma of some plants, as those quoted by Linnaeus, has an intensely un- pleasant action. The disagreeable marsh smell may be experienced in its strongest form by squeezing the brown scum of a stagnant pond in the fingers, and applying them to the nose. The varieties of bad odours are endless. As sweetness is the proper pleasure of smell, the effect of a stink is the proper pain of the organ, — the influence origi- nating the peculiar form of misery that we are adapted to receive by means of this sense. The sensation may be speci- fied as the nose-pain. As it is of an intense, rather than a massive, character, we are stunned and discomposed, but not necessarily depressed or prostrated, by it. It resembles in this respect a bitter taste, and is contrasted with the massive pains of chillness, indigestion, or disgust. The expression is in accordance with the acuteness of the sensation ; being an intense contortion of the features, chiefly about the nose. A sort of hysteric smile may likewise be provoked. The peculiar sensation of an ill smell is often appealed to metaphorically, to express the feelings caused by human conduct. 12. The name pungent is applicable to a large class of odours ; and the quality enters as an ingredient into many more. Ammonia is the type of substances producing this sensation. Nicotine, the snuff odoar, is the best known ex- ample, — a substance having a chemical analogy to ammonia. Pepper, mustard, and many of the acid effluvia, have a pungent action. This effect, however, is not an olfactory effect in the proper sense of the word ; like astringency and acidity in taste, it would probably arise through the nose independently of the power of smell. Snuff-takers are often devoid of smell ; they lose the sense of sweet or repulsive in odours properly so called, but are still susceptible of the nicotine pungency. The influence flows through the same channel to the brain, and is of the same nature as pricking PUNGENT ODOURS. 169 the nose, or pulling out hairs, being conveyed by the nerves of common sensation. The excitement of pungency is a characteristic variety of the human consciousness — a species of agreeable sensation, interesting to study. It shows the effect of a sharp mechani- cal irritation of the nerves that does not amount to acute pain. A scratch, or a blow on the skin, an electric spark, a loud crash, a brilliant flame, a scorching heat, are all pungent effects, and seem to operate as causes of excitement. They rouse the system from ennui ; they are a species of intoxication. They exalt, for the time being, the tone of the mind. They come, therefore, to be one of the cravings associated with ennui, or depression of mind : they are, like- wise, a stimulus for bringing out the exuberance of the animal spirits in the j'oung and vigorous. 13. The ethereal is a distinct variety of the sensations of smell, and is probably a mixture of pungency with odour strictly so called. Alcohol and the ethers, including chloro- form and the substance first employed as an anaesthetic, will recall this effect. There can be no question that alcohol and the vinous aromas have true odours ; most probably, however, they have an influence upon other nerves than the olfactor}- — ^just as the fiery taste attributed to them is some- thing beyond the gustatory feeling. At all events, the odour is distinct. It is not destitute of sweetness, but something besides sweet is wanted to express it. The sulphurous and electrical odour, which is also the odour of ozone, may be referred to the same class. If we were to recognize a class of acrid odours, we should find that they are only a mixture of pungency and bad smell ; like many of the so-called empijreumatic odours resulting from the action of heat on vegetable bodies, as in the manu- facture of coal gas. 14. The appetizing smells might be treated as a class apart from the rest. The smell of flesh excites the carni- vorous appetite, and rouses the animal to pursuit. We may probably consider this influence as similar in its working to 170 SENSE OF SMELL. the first taste of savoury food ; by the law of feehng-prompted movement, it sets on the activity for an increase of the gratification. A savoury smell may partly give a commencing pleasure of digestion, and partly stimulate the appetite. The sexual excitement in some animals is induced by smell. Sympathy and antipathy are alike generated by odours. The influence of odours upon the voluptuous tender emotions has not escaped the notice of the poets. Cabanis observes that the odours of young animals are of a kind to attract, and, he considers, even to invigorate, the older. 15. Tastes, properly so called, affect only the gustatory nerves, and are, therefore, the same whether the nostrils are opened or closed. But many sapid bodies are also odorous. In the act of expiration accompanying mastication, especially [the instant after deglutition, the odorous particles are carried mto the cavities of the nose, and affect the sense of smell, or make their odour apparent. This effect is what we term flavour. Some bodies, as cinnamon, have hardly any taste, but have a flavour, in other words an odour, brought out by mastication. The sensation takes some time to develop, after the contact of the stimulus with the olfactory membrane, aud may last very long. When the stimulus is repeated, the sensation very soon dies out : the sensory terminal organs speedily become exhausted. The larger, apparently, the surface of olfactory membrane em- ployed, the more intense the sensation : animals with acute scent have a proportionately lai'ge area of olfactory membrane. The greater the quantity of odoriferous material brought to the membrane, the more intense the sensation up to a certain limit ; and an olfactometer for measuring olfactory sensations has been constructed, the measurements being given by the size of the superficial area, impregnated with an odoriferous substance, over which the air must pass, in order to give rise to a distinct sensa- tion. The limit of increase of sensation, however, is soon reached, a minute quantity producing the maximum of sensation and further increase giving rise to exhaustion. The minimum quan- tity of material required to produce an olfactory sensation may SMELL AS AN INTELLECTUAL INSTRUMENT. 3 71 be, in some cases, as in that of musk, almost immeasurably small (Foster, .1 Text-book of Phtjsiology, p. 1389). 16. Smell, like taste, is an important instrument in the discrimination of material bodies, and, therefore, serves a high function in guiding our actions and in extending our know- ledge of the world. Man does not exemplify the highest development of this organ. The order of ruminants, certain of the pachydermatous animals, and above all the carnivorous quadrupeds, excel the human subject in the expansion given to the membrane of the nose, and in a corresponding sensi- bility to odours. The scent of the dog is to us almost miraculous ; it directs his pursuit, and tells him his where- abouts. It may act the part of sight in enabling him to retrace his steps or to find out his master. SENSE OF TOUCH. 1. Physiologists, in describing the senses, usually com- mence with Touch. ' This,' say Messrs. Todd and Bowman, 'is the simplest and most rudimentary of all the special senses, and may be considered as an exalted form of common sensation, from which it rises, by imperceptible gradations, to its state of highest development in some particular parts. It has its seat in the whole of the skin, and in certain mucous membranes, as that of the mouth, and is therefore the sense most generally diffused over the body. It is also that which exists most extensively in the animal kingdom ; being, probably, never absent in any species. It is, besides, the earliest called into operation, and the least complicated in its impressions and mechanism.' It may be well admitted that Touch is less complicated than Taste, in whose organ four different kinds of sensations may be said to meet, the tactile being one of them. It may be further said of touch, that the mode of action (mechanical contact or pressure) appears to us the most simple of any. Nevertheless, touch is an intellectual sense of a far higher order than either taste or smell. It is not merely a knowledge- giving sense, as all the senses are, but a source of ideas and 172 SENSE OP TOUCH. conceptions of the kind that remain in the intellect and embrace the outer world. The notions of the size, shape, direction, distances, and situation of external bodies may be acquired by touch, but not by either taste or smell. But this last assertion must be accompanied by an important explanation. Touch, considered as a source of ideas such as those, is really not a simple sense, but a com- pound of sense and motion ; and it is to the muscular part of the sense, or to the movements of the touching organs, that these conceptions owe their origin and their embodiment, as we have endeavoured to show in the previous chapter. The superiority of touch to taste and smell, in this view, therefore, consists in its union with movement and muscular sensibility ; and the same advantage pertains to sight. The contact of solid bodies with the surface of the body gives occasion to the exercise of movement, force, and resistance, and to the feelings and perceptions consequent on these : which cannot be said to any extent of smell, or of taste properly so called. A second feature marking the superiority of the sense of Touch, and qualifying it to furnish intellectual forms and imagery, is the distinctness or separateness of the sensations felt over the different parts of the skin. The sensations of the different parts of the surface of smell, would seem all to fuse into one stream of sensibility, it is barely possible ever to refer a smell to any one portion of the membrane more than another. But the sensations of the skin are conveyed by distinct nervous filaments ; each little area of skin has a separate nerve, and an independent communication with the nerve centres, whereby we can, after a little education, refer each sensation to the spot where the contact is made. The stimulus on one finger is not, at any part of the course of the nerve, confounded with the stimulus on another finger ; the back can always be distinguished from the breast, the right side from the left, and so on. I shall afterwards endeavour to show that this localization of touches has to be SUPERIORITY OF TOUCH, 17:3 learned by practice ; but the very possibility of it rests upon the distinctness and independence of the nerve filaments. This is an extremely important fact, and makes the great difference between touch and what is sometimes called ' common sensation,' or the sensibility diffused over all the internal organs and tissues. There is no such distinguishing sensibility in the stomach, or the lungs, or the liver : at all events, the distinctness of the nerves in those parts is very low in degree, just sufhcient to enable us to refer a pain to the lungs, the liver, or the stomach, without indicating the particular region or sub-division. The skin is, therefore, marked by a great exaltation of the common sensibility of the body, not as regards intensity of feeling, but as regards distinctiveness of locality. 2. Having made these preliminary remarks, we commence, as usual, with the objects, or external agents, concerned in the sense of Touch. These are, principally, the solid substances of the outer world. Gases do not act on the touch, unless they are blown with great violence. Liquids also give very little feeling, if they are of the same warmth as the body. The sensations of a bath are confined to heat or cold. It is manifest that an even, equal pressure, such as fluids give, is not sufficient to impress the tactile nerves. The asperities and inequalities of solid surfaces, by pressing intensely on some points and not at all on others, are requisite for this purpose. The hard, unyielding nature of the mineral constituents of the earth's crust, metals, rocks, etc., is well fitted to excite the touch. The woody fibre of the vegetable world has a compactness next in degree to the solid minerals. The soft and yielding class of solids impress the surface in a totally different manner : and these differ among themselves ac- cording as they recover their form after pressure, or not ; whence the distinction of elastic and non-elastic. When the substance is moved over the skin, the asperities come to be felt more acutely, and hence the further distinction into rough and smooth surfaces. In treating of the sensa- 17-i SENSE OF TOUCH. tions themselves, we shall attend to these qualities more minutely. 3. The sensitive organ or surface is the Skin, or common integument of the body, the interior of the mouth, and the tongue. The parts of the Skin are its two layers, its papillae, the hairs and nails, its two species of glands, — the one yielding sweat, the other a fatty secretion,- — with blood- vessels and nerves. I shall quote a few extracts from the anatomical description of those parts. ' Of the two, layers, the outermost is the cuticle, epidermis, or scarf skin. It forms a protective covering over every part of the true skin. The thickness of the cuticle varies in different parts of -the surface, measuring in some places not more than o^oth, and in other parts, as much as irxth of an inch (about one milli-. metre), or even more than this in some individuals. It is thickest in the palms of the hands and soles of the feet, where the skin is much exposed to intermittent pressure, and not improbably such pressure may serve to stimulate the subjacent true skin to a more active formation of epidermis ; still the difference does not depend immedi- ately on external causes, for it is well marked even in the foetus. ' The more firm and transparent superficial part, or horny layer, of the epidermis, may be separated after maceration from the deeper, softer, more opaque and recently formed part, which constitutes what is called the Malpighian layer, or rete mucosum. ' Many of the cells of the cuticle contain pigment-granules, and in parts give the membrane more or less of a tawny colour, even in the white races of mankind ; the blackness of the skin in the negro depends entirely on the cuticle. The pigment is contained principally in the cells of the deep layer or the rete mucosum, but even the superficial part possesses a certain degree of colour. ' The true shin, cutis vera, derma, or corium, is a sentient and vascular fibrous texture. It is covered and defended by the non-vascular cuticle, and is attached to the parts beneath THE SKIN. 175 by a layer of areolar tissue, named " subcutaneous," wbich, excepting in a few parts, contains fat, and has therefore been called also the " panniculus adiposus ". The connexion is in many parts loose and movable, in others close and firm — as on the palmar surface of the hand and the sole of the foot, where the skin is fixed to the subjacent fascia by numerous stout fibrous bands : the space between being filled with a firm padding of fat. In some regions of the body, the skin is moved by striated muscular fibres, which, as in the case of the orbicular muscle of the mouth, may be unconnected with fixed parts, or may be attached beneath to bones or fascine, like the other cutaneous muscles of the face and neck, and the short palmar muscle of the hand. ' The free surface of the true skin is marked in various places with larger or smaller furrows, which also affect the superjacent cuticle. The larger of them are seen opposite the flexures of the joints, as those so well known in the palm of the hand and at the joints of the fingers. The finer furrows intersect each other at various angles, and may be seen almost all over the surface ; they are very conspicuous on the back of the hands. Fine curvilinear ridges, with in- tervening furrows, mark the skin of the palm and sole ; these are caused by ranges of the papilla3, to be immediately described.' ' Papillce. — The free surface of the corium is beset with small eminences thus named, which seem chiefly intended to contribute to the perfection of the skin as an organ of touch, seeing that they are highly developed where the sense of touch is exquisite. They serve also to extend the surface for the production of the cuticular tissue, and hence are large-sized and numerous under the nail. The papillfe are large, and in close array on the palm of the hand and palmar surface of the fingers, and on the corresponding parts of the foot. In these places they are ranged in lines forming the characteristic curvilinear ridges seen when the skin is still covered with its thick epidermis. They are of a conical 176 SENSE OF TOUCH. figure, rounded or blunt at the top, and sometimes cleft into two or more points when they are named compound papillae. They are received into corresponding pits on the under-surface of the cuticle. In structure they resemble the rest "FioTn.*' ' of the superficial layer of the corium, and consist of a finely fibrillated tissue, with a few elastic fibres. The bundles of fibrils chiefly run parallel to the axis of the papilla ; and the fibrils appear to end near its surface, which has a somewhat corrugated aspect. On the palm, sole, and nipple, w^here they are mostly of the compound variety, thej^ measure from ^Jotb to tw^^^^ oi aq inch (0*125 to 0*25 mm.) in height. In the ridges, the larger papillae are placed sometimes in single but more commonly in double rows, with smaller ones between them ; that is, also on the ridges, for there are none in the intervening grooves. These ridges are marked at short and tolerably regular intervals with notches or short transverse furrows, in each of which, about its middle, is the minute funnel-shaped orifice of the duct of a sweat-gland. In other parts of the skin, endowed with less tactile sensibility, the papillae are broader, shorter, few-er in number, and irregularly scattered. On the face, they are reduced to from ^-^o^ti to -^o^h of an inch ; and here they at parts disappear altogether, or are replaced by slightly elevated reticular ridges. Fine blood- vessels enter most of the papillae, forming either simple capillary loops in each, or dividing into two or more capillary branches, according to the size of the papilla and its simple or composite form. Other papillse receive nerves ' (Quain's Anatomy, ■[ 10th edition, p. 415). * 'Papilhe of the palm, the cuticle, being detached.— Magnified 35 diameters ' (Todd and Bowman). t Inside the papillse are either nerves or blood-vessels, seldom both ; and, at their base, the nerves are disposed in the form of network. In great part of the skin, the nerves cannot be traced farther than this network ; it is in the hands, feet, lips (red part), and tongue, that^they are followed into the interior THE PAPILLA. 177 I have quoted the description of the papillae at length because of their connexion with the sensibility of the skin. I shall refrain frQin quoting the minute account of the nails and hairs, however interesting their structure in other points of view. Eespecting the glands, it is only necessary to advert to the totally different nature of the two sorts, as respects the material secreted. Sweat-glands exist most numerously in regions unprovided with hairs, but they occur in all parts of the skin, and may in some cases open into hair-follicles. According to Krause, nearly 2800 open on a square inch of the palm of the hand, and somewhat fewer on an equal extent of the sole of the foot. He assigns rather more than half this number to a square inch on the back of the hand, and not quite so many to an equal portion of surface on the forehead, and the front and sides of the neck. On the breast, abdomen, and forearm, he reckons about 1100 to the inch; while, on the lower limbs and the back part of the neck and trunk, the number in the same space is not more than from 400 to 600. The Sebaceous or oil glands are small saccular glands, which pour out their secretion at the roots of the hairs ; for, with very few exceptions, they open into the hair-follicles, and are found wherever there are hairs. Each has a short of the papillie. In these parts, they end in a peculiar structure, linown as the ' little bodies of touch,' discovered by Wagner and Meissner. These are little sacks, covered by a thin skin, and filled with a round little mass. The skin is pierced by one or two nerves, which often wind spirally, but end by dividing and spreading their twigs in the little sack. These bodies lie in the interior of papillae destitute of blood-vessels, in such a manner as to project far above the upper end of the papillae, and in immediate contact with the cuticle. They are most numerous on the inside of the finger tips, and decrease toward the palm ; the same happens with the foot. Meissner found in a square line (tt¥ o^ ^ square inch) on the index finger, 108 on the last joint, 40 on the second, 15 on the first. In the red part of the lips, the papillae "carrying nerves are not distinguishable from those carrying blood-vessels, the same papilla appearing to have both. The little muscles discovered by Kolliker in the skin, and especially in the glands, excite peculiar movements as in shivering, the creeping sensation, etc. These are especiall}' affected by changes of temperature, and maj' serve to regxilate the supply of blood under such changes. 12 178 SENSE OF TOUCH. duct, which opens at a little distance within the mouth of the saccules, which, as well as the duct, are lined by epithe- lium, usually charged with the fatty secretion. These glands are lodged in the substance of the corium. They are usually placed on the side to which the hair slopes, and in the angle formed by the junction of the arrector pili with the hair, so that, when the muscular fibres contract, they tend to compress the gland. Several may open into the same hair- follicle, and their size is not regulated by the magnitude of the hair. Thus, some of the largest are connected w^ith the fine downy hairs on the alae of the nose and other parts of the face, and there they often become unduly charged with pent-up secretion. 4. With respect to the functions and vital properties of the skin in general, I quote the following summary : — ' The skin forms a general external tegument to the body, defining the surface, and coming into relation with foreign matters externally, as the mucous membrane, with which it is continuous and in many respects analogous, does internally. It is also a vast emunctory, by which a large amount of fluid is eliminated from the system, in this also resembling certain parts of the mucous membrane. Under certain conditions, moreover, it performs the office of an absorbing surface ; but this function is greatly restricted by the epidermis. Through- out its whole extent the skin is endowed with tactile sensi- hilitij, but in very different degrees in different parts. On the skin of the palm and fingers, which is largely supplied with nerves and furnished with numerous prominent papillae, the sense attains a high degree of acuteness ; and this endowment, together with other conformable arrangements and adaptations, invests the human hand with the character of a special organ of touch. A certain, though low degree of vital contractility, seems also to belong to the skin.' Of the other parts sensible to Touch, besides the skin — namely, the tongue and mouth, — the needful description has been already furnished, under the sense of Taste. The nerves of touch are the sensory or posterior roots of DIFFERENT CLASSES OF SKIX NERVES. 179 the spinal nerves, for the hmbs and trunk, and certain of the cerebral nerves (the fifth pair), for the head, face, mouth, and tongue.* Before distinguishing and classifying the various modes of tactile sensibility, it is expedient to consider the bearings of observations that have been made as to the different kinds of nerves distributed to the skin. It seemed at one time not unreasonable to suppose that the same class of nerves might convey to the brain all the various modes of impressing the skin by external agents ; as, for example, pressure, tem- perature, pleasure and pain. The difference of the mode of action in mere pressure, and in heat or cold, is not such as apparently to disqualify one set of nerves from embodying and transmitting the effect to the brain, any more than the variations of one of these several modes. It is equally difficult to explain the mode of analyzing the various lines of transmission in the brain itself, whether there be only one or more than one class of nerves employed. It is a considerable time since the suggestion was made that we have a distinct class of nerves for temperature, — that is, for heat and cold. Observations and experiments in favour of this distinctness have been frequently adduced. The point is a purely matter-of-fact determination, and not one of a jjriori ■ or theoretical probability or improbabilit}'. As to subjectivit}', our description of the actual feelings of tem- perature would remain the same whatever might be the conclusion come to on this head. Still, it is not uninterest- ing to be able to satisfy ourselves as to the paths whereby impressions of temperature find access to the brain. The conclusions now come to by physiological research depend upon a special mode of experimentation, called ' the punctiform method of exploring the sensitiveness of the skin '. By this method, not only is confirmation given * It is supposed that the important nerves of touch in the extremities have a different course in the hrain from the nerves of the trunk. Tiirk has shown that in the hand and in the foot the same spot is supplied from dif- ferent roots in the spinal cord. 180 SENSE OF TOUCH. to the distinctiveness of nerves of temperature, but the further result has been reached that the same fibres are not ahke available for heat and for cold : a result not altogether free from the air of paradox ; nevertheless, if sufficiently attested, we are bound to accept it. Any difficulty of a psychological nature that might arise would land in the embroilment of our usual views of relativity or contrast. This is not all. The employment of the same method is looked upon as revealing still another class of distinct nerves, — namely, nerves of pure Pain. The meaning is, that the nerves of pressure and of temperature, while revealing those charac- teristic sensibilities, present them to our consciousness more as intellectually distinct sensibilities than as the media of our pronounced states of pain and pleasure. In fact, when those sensibilities, through intensit}^ of stimulation, are made to yield decided forms of pain or pleasure, another set of nerves is brought into play : the appropriate nerves declining the task of conveying a sensibility involving so important an addition to their own characteristic function. Here, too, we must admit something of the nature of paradox. The psycho- logical estimate of our tactile sensations must still rest upon our subjective experience ; yet, the manner of conveying to the brain the different effects of the agencies of touch cannot fail to influence our views and our language as dictated by subjective analj^sis. In handling this part of the physiology of touch. Professor Foster has taken a wider view of the distribution of nerves of pain in the body at large. He regards these nerves as the true media of general or common sensibility, and, as supplied in that character to the viscera no less than to the skin, yiekling to con- sciousness the painful sensibilities accompanying their abnormal phases or times of disturbance or irritation. This generalization is liable to various difficulties. It says nothing of common sensi- bility as organic pleasure — a fact that cannot be excluded from the consideration of either the skin or the internal viscera. Sen- sations of temperature, for example, are almost nothing if not pleasurable or painful. If the proper nerves of temperature refuse SOFT TOUCH. 181 to convey these modes, the so-cahed nerves of pain or common sensibihty must perform that office, and, if so, are quite as much nerves of pleasure as of pain. As regards visceral sensibihty, there seems every reason for the course ah'eady taken in discussing Organic Sensations, — namely, to examine the different visceral organs apart, and to describe the sensations of each according to the results of our conscious examination. A certain character of common or general sensibility attaching to these sensations has already been allowed for (see p. 107), as far as the evidence of consciousness seemed to justify. 5. We come now to the sensations, or feelings, of Touch; vi'hich are various in kind, and have many of them a con- siderable degree of interest, from their bearing on the higher operations of mind. In the order of enmneration, I shall commence, as usual, (I.") with those having reference to pleasure or pain, or that may be called predominantly emotional. Sensations of Soft Touch. — Under this head, there is a great and wide-ranging sensibility, but in its nature highly complex. There is supposed the gentle contact of some extended surface with the skin. Some feeling of tempera- ture usually concurs, and in favourable circumstances en- hances the effect. Yet, irrespective of agreeable warmth, we have experience of a pleasurable effect, which we attribute to touch by itself. The occasions that can be cited for the pure case of soft extended contact are numerous and well known. From various circumstances, the feeling is but little attended to; yet, it may be made a subject of consciousness — in which case, it is nourished by the appropriate operation of the will. The contact of the soft clothing would necessarily be an example ; and is so, at the first moment after assuming the ordinary dress, but insensibility naturally follows, owing to the law of accommodation to agencies that are uniform in their operation. It is, of course, the nature of this pleasure to be massive or voluminous, and not acute. It operates upon the will in 182 SENSE OF TOUCH. presence, but takes little hold of the intellect in absence. The feeling is essentially of the vague kind ; for which reason it resembles the other massive sensations of the same class, — such as gentle warmth, its frequent accompaniment. A notable manifestation of the sensibility is furnished by the contact of one part of the naked body with another. This, being occasional in its occurrence, mostly escapes the deadening influence of habituation or accommodation. Hence, it is perhaps the most marked instance of the effect, and the instance that most frequently rules the voluntary exertions. Many of our habitual attitudes and modes of outward expression are regulated by this particular pleasure. When the child puts its finger or hand to its mouth, we infer either a realized pleasure or a comforting sensation in pain or in distress ; and this species of contact of the hand with the parts of the face is practised all through life, seemingly from the same motives. The mutual contact of living animal bodies yields the complex sensation of softness and warmth; while, in peculiar circumstances, it induces much deeper sensibihties fed through the affections and emotions. The discussion of these is out of place at the present stage. There is an anomaly or paradox in the working of this sensibility, — viz., the connexion of comparative slightness of contact with the full amount of realized sensation. This, however, is not the only exception to the general law that connects amount or degree of stimulus with amount of feeliug, as will be seen again presently. 6. Pungent and Painful Sensations of Touch. — When, instead of a diffusive soft contact, we have an intense action on limited spots, mere points, as in th6 stroke of a whip, a sensation of smartness is produced very different from the above. This is the case that is supposed to evoke a sensation of pain, pure and simple, employing for the purpose the so-called specific nerves of pain, to the exclusion of those of pressure PUNGENT AND PAINFUL SENSATIONS. 183 and temperature. It is, however, not an instance of purel}' painful sensibility all through, like bitterness to taste, or stench to smell. There is a stage when pain is not reached, and when even a certain pleasure is derivable under the designation of pungency, — an effect attaching to all the five senses, and admitting of being delineated in its own proper character among our fundamental sensibilities to pleasure. The condition already laid down (p. 169) as attaching to its agreeable mode is a certain vigour and freshness in the sensi- tive surface, as well as in the nerves concerned. Certain of our characteristic and habitual expressions are connected with this form of skin pungency, and, as in the case of soft touch, are most frequently seen in assuaging some form of pain. Scratching the head, or squeezing and pinching the hands or other places, are well-known outlets in situations of doubt, difficulty, or painful uncertainty. For such ends, it is quite plain that we should not resort to any form of sensation that would be in itself an unqualified pain. After the small margin of pleasurable pungency, we reach the properly painful stage of acute skin contacts — from which we have a very marked sensibility. A common sub- jective character attaches to a mere smart without permanent injury, and to the various modes of wounding the tissue of the epidermis and dermis by violent applications or disease ; the acute extremes of heat and cold being included. According to the usual method of description, we may say that this is a state of painful sensibilit3^ acute rather than massive, with wide-ranging degree, from an insignificant amount to the utmost pitch of human torture. Its operation on the will is correspondingly great ; and, in its extreme acuteness, it has an advantage ni impressing the memory and constituting a motive for future avoidance. Hence its wide- spread employment in the discipline of sensitive beings. 7. Other Painful Sematiuns of th(' Skin. — Among these, I would first advert to the sensation of tickling. On this, Weber remarks, that the lips, the walls of the nasal openings, and the face generally, when touched with a feather, give the 184 SENSE OF TOUCH. peculiar sensation of tickling, which continues till the part is rubbed by the hand. In the nose, the irritation leads at last to sneezing. The excitation extends to the ducts of the glands, which pour out their contents, and increase the irritation. The violent commotion produced by bodies in contact with the eye is of the nature of tickling - accom- panied by a flow from the glands — and readily passes into pain. Why some places are liable to this sensation, and others not, it is diflicult to explain. The possession of delicate tactual discrimination is not necessary to the effect. Here we have, obviously, a far greater exception to the law of stimulus than the case of simple soft touch. The pain itself is altogether peculiar and anomalous. It cannot be ex- pressed or defined in terms of our usual painful sensibility. The ordinary cases of such sensibility that we have to deal with are one or other of the following : — -Either we have a stimulus painful in its nature in every degree, the pain increasing with the degree ; or we may have an agency pleasurable or else indifferent to a certain extent, and then becoming painful by injurious excess, the pain increasing according to the excess. But, in the case of tickling, we have the slightest conceivable stimulus with a violent form of pain, inspiring the will to efforts of intense revulsion ; the slightness of the stimulus being the condition of the effect. A little extra pressure deadens the sensibility and passes into the common routine of sensations of pressure. The tickling of the armpit or the soles of the feet would seem to awaken violent reflex movements, apart from or additional to the operation of the will consequent on the subjective feeling. The discomfort of these spasmodic out- bursts may be supposed to add to the revulsion caused by the tickle ; but they would not of themselves yield the pecu- liar agony of the state. The experience is altogether unique ; possibly, a special order of nerves may be connected with it. Although the sphere of sensibility is a narrow one, it has outgoings and applications in the higher regions of SENSATIONS OF TEMPERATUEE. 185 intelligence and emotion, as is shown by the employment of the name in a variety of situations that need not here be adverted to. It is both interesting and important to advert to the mibroken continuity of sensation in skin contact. We have reckoned among the pleasures of touch the soft extended contact, implying that simple touch of a sufficiently gentle sort is intrinsically grateful. By increasing the pressure, the pleasure is lost ; but reappears for a short range as a different species of agreeable sensibility, whence it passes into a mode of pain, in steady proportion to the intensity of the applica- tion. We have here a study of the law of stimulus, w^iich is partly exemplified and partly contradicted. Before com- menting further on the case, we have to allude to another anomaly in connexion with the present sense. The long-continued compression of the same part of the skin creates uneasiness. So, the friction or chafing of the skin, in a short time leads to discomfort and inspires repug- nance. This, too, is a somewhat exceptional form of painful sensibility, where the effect is out of proportion to the mechanical agency at work. It does not correspond either to the normal varieties of skin pressure, or to the exception of tickling. There is nothing gained by forcing it under either head. Better treat it as a case apart — the starting-point of a wide reference in the higher regions of the mmd. The pre- cise nerves concerned might be those of pressure, or else those of pain, — that is, on the supposition that, wherever a skin sensation rises to pain, it operates solely through the class of nerves so designated. Clamminess is a distinct sensation arising from the ad- hesion of a substance to the skin ; and is an uneasy feeling — the uneasiness being due to some interruption of the natural functions of the part. 8. (II.) Sensations of Temperature. — The feelings of heat and cold, regarded as pleasurable or painful, have been noticed under the Organic Sensations in general (see p. 134). Although viewed in connexion witli the organs generally. 186 SENSE OF TOUCH. undoubtedly their chief seat, as a source of pleasure and pain, no less than of discriminative judgments, is the skin. It has already been noted that the consensus of physio- logical opinion is in favour of assigning a distinct class of nerves to sensations of temperature. AVhether these are the nerves that convey the pleasurable or the painful impressions is not distinctly stated. In fact, a certain ambiguity rests upon this part of the hypothesis of three independent sets of tactile nerves. While it is taken for granted that, in every case of pain, the nerves of pain are the seat, even although the sensation is merely an excessive stimulus of one of the other two classes, nothing is ever said as to the localization of pleasurable sensibility, although this is a very notable adjunct of heat in particular. Without entering further into the nature of heat and cold as sources of pleasurable and painful sensibility, having already adverted to the topic at sufficient length, we now pro- ceed to consider the bearings of these particular sensibilities upon our judgment of outward objects. As regards the dis- crimination of degrees of Temperature, it appears that we are equally sensitive at high and at low points of the thermometer. According to Weber, we can discriminate 14° Eeaumur from 11"4", as well as 30" from 30*4° ; and the discrimination is all the better by the change being rapidly made. It is also better when the unequal temperatures are applied at the same time to contiguous parts, than w^hen the parts touched are remote from each other. The sensi- tiveness of different parts to temperature is not solely dependent on the abundance of nerves supplied to the part ; some other circumstance at present miknown is in operation. Weber's graduated scale for heat is as follows : — Tip of the tongue, eyelids, lips, neck, trunk. In the face, breast, and abdomen, the central parts are less sensitive than the sides. The sensitiveness is increased by extent of surface. In an experiment with dipping the finger into water at 32° B., and the whole hand in 29r, the latter appeared the warmer of the two. INTELLECTUAL SENSATIONS. 187 It is remarked that, when one part of the body touches another, the temperature being the same, the part endowed with the finer tactile power feels the other. If the tem- peratures are different, the first feels the second factually, while the second feels the temperature of the first. The hand is not felt factually by the brow, nor is the coldness of the brow felt by the hand. It is a singular fact, discovered by Weber, in connexion with the sense of temperature, that, when two substances of the same weight, but of different temperatures, are estimated by the sense of touch or of pressure, the colder appears the heavier. The depressing effect of the cold chill upon the mind may be the explanation. This is somewhat analogous to the perversion of our estimate of time by an uniisual elation or depression of the general mental tone : in the one case, we imagine it to pass rapidly ; in the other, too slowly. The feeling of temperature is an element in many dis- criminations, — as in the distinction between stone and wood. We pass now (III.) to the more peculiarly intellectual sensations of Touch ; and, first, to cases of Touch simply. 9. (1) Impressi&ns of Distinguishable Points. — I have already called attention to the discriminative character of the sense of touch, whereby it receives distinguishable impressions from the variously situated parts of an extended surface. Very interesting differences in the degree of this discrimi- nation are observable on different parts of the surface of the body, which have been especially illustrated by the experi- ments of AVeber. ' These consisted in placing the two poiuts of a pair of com- passes, blunted with sealing wax, at different distances asunder, and in various directions, upon different parts of the skin of an individual. It was then found, that the smallest distance at which the contact can be distinguished to be double, varies in different parts between the thirty-sixth of an inch and three inches ; and this seems a happy ci'iterion of the acuteness of the sense. We recognise a double impression on very sensible parts of the skin, though the points are very near each other ; wliile. 188 SENSE OF TOUCH. in parts of less acute sensibility, the impression is of a single point, although they may be, in reality, far asunder. 'In many parts we perceive the distance and situation of two points more distinctly when placed transversely, than when placed longitudinally, and vice versa. For example, in the middle of the arm or forearm, points are separately felt at a distance of two inches, if placed crosswise ; but scarcely so at the dis- tance of three, if directed lengthwise to the limb. ' Two points, at a fixed distance apart, feel as if more widely separated when placed on a very sensitive part, than when touching a surface of bkxnter sensibility. This may be easily shown by drawing them over regions differently endowed ; they will seem to open as they approach the parts acutely sensible, and vice versa. ' If contact be more forcibly made by one of the points than by the other, the feebler ceases to be distinguished ; the stronger impression having a tendency to obscure the weaker, in propor- tion to its excess of intensity. ' Two points, at a fixed distance, are distinguished more clearly when brought into contact with surfaces varying in structure and use, than when applied to the same surface, as, for example, on the internal and external surface of the lips, or the front and back of the finger. ' Of the extremities, the least sensitive parts are the middle regions of the chief segments, as in the middle of the arm, fore- arm, thigh, and leg. The convexities of the joints are more sensible than the concavities. ' The hand and foot gi-eatly excel the arm and leg, and the hand tlie foot. The palms and soles respectively excel the opposite surfaces, which last are even surpassed by the lower parts of the forearm and leg. On the palmar aspect of the hand, the acuteness of the sense corresponds very accurately with the development of the rows of papillae ; and where these papillae are almost wanting, as opposite the flexions of the joints, it is feeble. ' The scalp has a blunter sensibility than any other part of the head, and the neck does not even equal the scalp. The skin of the face is more and more sensible as we approach the middle line ; and the tip of the nose and red parts of the lips are acutely DISTINGUISHABLE POINTS. 18f> SO, and only inferior to the tip of the tongue. This last, in a space of a few square lines (a line is yV of an inch), exceeds the most sensitive parts of the fingers ; and points of contact with it may be generally perceived distinctly from one another, when only one-third of a line intervenes between them. [The superior sensibility of the tip of the tongue to the finger, is illustrated by the familiar observation, that a hole in a tooth seems very much exaggerated when felt by the tip of the tongue.] As we recede from the tip along the back or sides of the tongue, we find the- sense of touch much duller. ' The sensibility of the surface of the trunk is inferior to that of the extremities or head. The flanks and nipples, which are so sensitive to tickling, are comparatively blunt in regard to the- appreciation of the distance between points of contact. Points placed on opposite sides of the middle line, either before or be- hind, are better distinguished than when both are on the same side. ' The above are the results obtained by making the several parts mere passive and motionless recipients of impressions. They evince the precision of the sense in so far only as it depends on the organisation of the tactile surface. The augmented power derived from change pi position of the object with regard to the surface, is well illustrated by keeping the hand passive, while the object is made to move rapidly over it. In this case the- contact of the two points is separately perceived, when so close that they would, if stationary, seem as one. If, still further, the fingers be made to freely traverse the surface of an object, under the guidance of the mind, the appreciation of contact will be far more exquisite, in proportion to the variety of the movements, and the attention given to them. We are then said to feel, or to examine by the sense of touch' (Todd and Bowman, i. 429-30). These observations of Weber have been deservedly celebrated by physiologists, as the foundation of an accurate mode of estimating the tactile sensibility of the skin. They have been extended by other observers, as may be seen in Dr. Carpenter's article on Touch in the Cydopccdia of An- atomy. 190 SENSE OF TOUCH. The following is a selection from Weber's measurements. The intervals are expressed in lines, a line being the twelfth part of an inch. The range, according to Weber, is from the twenty-fourth of an inch, in the tip of the tongue, to two and a half inches. The range stated in the text is somewhat greater, being founded probably on a comparison of the extreme observa- tions of different observers : — Tip of the tongue ..... Tip of the forefinger, palmar surface . Eed surface of under lip . Second joint of the fingers, palmar surface Last joint of the fingers, back or dorsal surface Tip of the nose ...... Middle of the back of the tongue End of the great toe ..... Palm of the hand ..... Cheek, over the buccinator Lower part of the forehead Back of the hand ..... Crown of the head ..... Thigh, by the knee ..... Upper and lower extremities of the legs Breast ....... Back of neck near occiput .... Middle of forearm, middle of thigh, middle of the back of the neck, middle of the back . 30 ,, If the points are placed within the limit of doubleness and gradu- ally separated, the interval that gives doubleness is greater than in the reverse process. The delicacy in our perception of plurality admits of improve- ment by practice, like most other kinds of discrimination. The possibility of such acquisition would seem to show that the primitive sense of interval is not physiologically fixed by nerve areas, or the number of ultimate filaments supplied to each spot of doubleness. As we cannot create new filaments, in order to narrow the interval of perceived doubleness, there must be some other way of viewing the process of augmented discrimination. This will be taken up again, under acquired discrimination generally. i i of a line 1 (^V of an inch) 1 line 2 lines 2 3 3 4 o 5 5 . 10 . 14 . 15 . 16 . 18 . 20 . 24 SENSATIONS OF PRESSURE. 191 It is important to observe, that the primitive susceptibihty to a plurahty of distinct points does not enable us to judge what the real distance of the points is ; nor can we tell, previous to experience, whereabouts on the body the im- pression is made. Hence, in those of the experiments that concern our sense of the relative interval of the points, as when they pass from a duller to a more sensitive region, there are involved perceptions that we have got at by some other means than through the sense of contact. This other means is the feeling of movement or the muscular sensibility, without which it is impossible to comprehend fully the sen- sations of Touch. 10. (2) Sensations of Pressure.— ^Se have already noticed (p. 183) the gradations of sensibility under varpng degrees of pressure, or skin compression, up to the extreme modes of acute or painful intensity. The only consideration then taken into account was the production of pleasure or pain. Degrees of pressure are now to be viewed in another light, — VIZ., as discriminated in amount, with a view to measure the outward stimulating agency. This discrimination may go along with a certain amount of pleasurable or painful feeling, or with the absence of such feeling from the con- sciousness. The mere circumstance of solid contact with the skin is a mark of so much mechanical force, and both suggests that fact and measures its amount. Only experience can tell what is the degree of delicacy of this special discrimination. The determination of the degrees of forcible contact with the skin is, in actual practice, mixed or compound ; that is to say, another sensibility shares in the operation, — namely, the muscular, — and is found to be the more effectual of the two. This last can be with- held from co-operating by pressing upon a limb artificially supported so as to remove the play of the muscles. Thus, when the hand lies on the table, the effect is one of pressure solely. The most sensitive parts, as the tips of the fingers, can distinguish 20 oz. from 19"2 oz. ; the forearm dis- tinguishes 20 oz. from 18'7 oz. The interval of time affects 192 SENSE OF TOUCH. the discrimination, as we might suppose. The difference between 14, or even 14'5, could be distincruished from 15, within 30 seconds ; 4 and 5 could be distinguished within 90 seconds. The discrimination of pressure does not increase propor- tionably with the supply of tactile nerves. 11, (IV.) Sensations of Touch Involving Muscular Perceptions. — In discussing these, we shall begin with examples that are almost purely muscular, the tactile sensibility being a mere incident of the situation. The feeling oiiceight is of this description ; depending on the sense of muscular exertion, although capable also of being estimated, to some extent, by the feeling of compression of the skin. On this last point, I add some further illustrations from Messrs. Todd and Bow^man. 'Weber performed experiments to ascertain how far we are capable of judging of weight by the mere sense of contact [without muscularity] . He found that when two equal weights, every way similar, are placed on corresponding parts of the skin, we may add to, or subtract from one of them a certain quantity without the person being able to appreciate the change ; and that when the parts bearing the weights, as the hands, are inactively resting upon a table, a much greater alteration may be made in the relative amount of the weights without his perceiving it, than when the same parts are allowed free motion. For example, 32 ounces may thus be altered by from 8 to 12, when the hand is motionless and supported ; but only by from 1\ to 4, when the muscles are in action ; and this difference is in spite of the greater surface affected (by the counter pressure against the support) in the former than in the latter case. Weber infers that the measure of weight by the mere touch of the skin is more than doubled by the play of the muscles. We believe this estimate to be rather under than over the mark ' (p. 431). That the discriminating sensibility of the skin to degrees of compression may operate in appreciating weight is further confirmed by the following statement. ' The relative power RESISTANCE. 193 of different parts to estimate weight corresponds very nearly with their relative capacities of touch. Weber discovered that the lips are better estimators of weight than any other part, as we might have anticipated by their delicate sense of touch and their extreme mobility. The fingers and toes are also very delicate instruments of this description. The palms and soles possess this power in a very remarkable degree, especially over the heads of the metacarpal and metatarsal bones ; while the back, occiput, thorax, abdomen, shoulders, arms, and legs, have very little capacity of esti- mating weight' {ih., p. 432). What is said of weight applies to any other form of pressure, force, or resistance. The impetus of a push or a squeeze received on the hand is measured by the muscular exertion induced to meet it, and, in some small degree, as already described, by the compression of the skin and other parts at the place of contact. It must not be supposed that we could derive our original feeling of resistance, with its reference to the object world, by mere tactile sensibility through pressure. The sense of resistance is primarily the feeling of expended energy. When the notion is once formed, we can remark that the degrees of resistance coincide with degrees of the tactile sensibility to pressure ; and, hence, the passive feeling can suggest the active, and become a criterion of its amount. The qualities of hardness and softness are appreciated by this combined sensibility : the one means a greater resistance to compression, and the other a less. From the unj'ielding stone or metal to the mobility of the liquid state, we have all degrees of this property ; the entire class of soft, viscous, and fibrous substances lying between. It belongs to various manual arts to appreciate minute differences of consistence in the class of soft bodies ; the pastry-cook, the builder, the sculptor, etc. In this, they are assisted by practice, which improves all sensibilities ; but there are great varieties of natural endowment in the case, which varieties must have 13 194 SENSE OF TOUCH. their seat principally in the muscular tissue, and only second- arily in the skin and nerves of the hand. The feeling of elasticity is a case of simple resistance to force, exerted in the particular circumstance of a rebound or increasing reaction from pressure. The elasticity implies a perfect return to the original position. Air is elastic : so is a steel spring ; meaning that, when in any way com- pressed or distorted, it recovers itself. We may, next, consider the sensations arising from the qualities of roughness and smoothness. Simple contact, we have seen, gives the sense of a multiplicity of points. The finger resting on the end of a brush makes us aware of the character of the brush ; that is, we have the feeling of a plurality of pricks. In this way, we are sensitive to rough and pointed surfaces. AVe can distinguish between bluntly- pointed asperities, like a file, and sharp points, like a horse- comb ; the sensibility arising from a blunt point being distinct from that of a needle-prick. We can also dis- tinguish between thick-set points and such as are more scattered, provided they are not too close for the limits of sensibility of the part, — that is to say, one-twelfth of an inch for the finger, and one-twenty-fourth to one-thirtieth for the tip of the tongue. On the back, the calf of the leg, and the middle of the forearm, where points are confounded up to the distance of tw^o and a half to three inches, rough- ness would be altogether imperceptible. In these instances, the thing touched is supposed to lie at rest on the finger, or on the part touched. But this does not do full justice to the tactile sensibility : we should move the finger to and fro over the surface, in order to try to the utmost the power of discrimination. We may thus dis- criminate far nicer shades of roughness ; we may appreciate minuter intervals than in the resting position. Supposing the sensibility of the tip of the finger at rest to be one line, by motion we can extend this sensibility to an unknown limit. The case may be illustrated by the micrometer screw on an astronomical instrument. The divisions on ROUGHNESS AND SMOOTHNESS. 195 the limb of the instrument extend, we may suppose, to one minute of a degree ; and if the index he between two divis- ions, its place can be measured by the number of turns of the screw required to bring it up to one of the divisions. So, if a point is undistinguished on the finger, in conse- quence of not being a line removed from the neighbouring point, we may estimate its distance, nevertheless, by the amount of motion of the finger needed to bring it into the limit of sensibility. I will take as an example a row of five points, one-fortieth of an inch apart, the extremes being one-tenth, which is the sensibility of the tip of the finger. This row would be felt as two points if the finger were stationary. But, by the motion of the finger, one point would pass away and another would come up, and there would be a feeling of the interval moved over between the perception of the successive points, which would be a measure of the intervals. The sense of movement would thus be brought in to aid the tactile feeline;, and to reveal a degree of closeness in asperities beyond the reach of touch unassisted by motion. It is consistent with all experience, that the roughness of" a surface becomes far more apparent by drawing the hand over it. We must, however, further consider that friction creates a new variety of pressure on the skin and nerves ; and the kind of friction is so different for a smooth and for a rough body, that by it alone we might learn to distinguish between the rough and smooth contact. The chafing action formerly adverted to as a mode of painful skin sensibility possesses a certain delicacy of discrimination of amount, which avails as an estimate of surface asperity in the object causing it. Whatever may be the explanation of the increase of sensibility due to movement, the fact is an important one. A large amount of discrimination turns upon it. From the variety of trace made by different kinds of surface, we can distinguish them or identify them at pleasure, up to a con- siderable limit of delicacy. Hence the power of telling substances by the touch, and of deciding on the qualities and 196 SENSE OF TOUCH. merits of texture and of workmanship. Degrees of polish in stone, metal, or wood, the fineness of cloths, wool, etc., the beat of a pulse, the quality of powdered substances, and many things besides, are matters of judgment and compari- son to the touch, and put to the proof its natural or ac- quired delicacy. These tactile sensations, whereby surfaces are discrimi- nated, have a great degree of persistence in the recollection ; something intermediate between tastes or smells, and sights. We do not revel in them as imagery, it is true ; but this would be accounted for by the superior hold that we have of the very same objects by means of sight. AYiththe blind, the case is diiferent. To them, the outer world must be re- presented as outspread matters of contact ; their notions of the surfaces of all things are notions of touch. Our permanent impressions of touch serve us for com- paring present surfaces with remembered ones, and for identifpng or distinguishing the successive objects that come before the view. The cloth dealer is aware whether a given specimen corresponds with another piece that passed through his hands a week ago, or with a permanent standard impressed upon his finger sensibility. 12. Qualities of Extension, Size, Form, etc.^I have endea- voured to show, in the previous chapter (p. 93), that these qualities are impressed upon us by the movements they cause, and that the feelings they produce are feelings of movement or muscularity. It is now to be seen how far the sense of Touch proper enters into our notions of the fundamental property of the Object world, namely. Exten- sion, of which Distance, Direction, Position, and Form are only special modes or applications. When we examine closely the sensibilities obtained by movement alone, as by passing the arm to and fro in empty space, we find that these have various shortcomings as regards the idea of extended matter, or extended space. In the first place, the absence of some definite marks, to indicate the commencement and the termination of a mus- EXTENSION. 197 cular sweep, leaves a certain vagueness in our feeling of mere movement. The feelings of putting forth power, and of this power taking the form of movement as distinct from dead strain, are present in all cases ; but the mind is more alive to them when some definite impression marks where we begin and where we cease. Now, the sense of touch supplies this impression, and furnishes, as it were, a call to attention. Let us suppose the hand moving between two fixed obstacles, — for example, from one side of a box to another. There is, to commence with, the contact with one side of the box felt more or less as a sense of touch, pressure, and re- sistance (a feeling partly muscular, but this need not be considered) : the abrupt departure from this state is a mark in consciousness, a call to attention ; and the mind is awakened to the feeling of movement that follows. After a time, the other side is struck, and the mind is again roused, and takes note of the cessation of the movement. The antithesis of resisting matter and unresisted movement is well brought out by such an experience ; there is in it some- thing more than the contrast of the swing of a limb with its undisturbed quiescence, which is all that movement in vacuo can give us. In the next place, when the hand is moved over a surface, touching it the while, the feeling of continuance of movement is accompanied by a feeling of continuance of tactile sensation, making the consciousness more marked and acute, and so enabling us to estimate the degree of con- tinuance more nicely. A feeling of the subject (touch proper) is superadded to the great object sensibility (expended energy as movement), and deepens the impress of that sensibility, without being able to take its place, or to constitute the feeling of objectivity. The peculiar tactile sensation that friction causes is thus a means of suggesting extension and of estimating it, although incompetent to supply the notion itself. In the third place, movement in vacuo seems unable to indicate that distinction between Succession and Co-exist- 198 ' SENSE OF TOUCH. ence — Time and Space — which must be arrived at before we can say that we recognize Extension. The continuance of movement is a fact that we are conscious of; in other words, we are conscious of a pecuhar mode of the putting forth of energy which varies in degree, and we remark one move- ment as different from another on this point. But, if any property of things is indicated by this, it would seem to be, not space, but time. In truth, neither is known; for, they are a correlative couple, not known at all till they are known together. Now, we are able to show how the embodying of our movements in sensation enables us to distinguish between the two facts or properties called the Co-existing and the Successive. When, with the hand, we grasp something moving, and move with it, we have a sensation of one unchanged contact and pressure, and the sensation is embedded in a movement. This is one experience. When we move the hand over a fixed surface, v/e have, with the feelings of movement, a succession of feelings of touch ; if the surface is a variable one, the sensations are constantly changing, so that we can be under no mistake as to our passing through a series of tactile impressions. This is another experience, and differs from the first, not in the sense of power, but in the tactile accompaniment. The difference, however, is of vital im- portance. In the one case, we have an object moving, and measuring time or continuance ; in the other case, we have co-existence in space. The co-existence is still further made apparent by our reversing the movement, and thereby en- countering the tactile series in the inverse order. Moreover, the serial order is unchanged by the rapidity of our own movements. A more rapid pass of the hand makes the series come up quicker ; a less rapid brings the same series in more slowly. By these experiences, we gradually become aware of a wide distinction between identical movements conducted under such different circumstances ; and the dis- tinction is expressed in language as succession and co- CO-EXISTENCE AND SUCCESSION. 199 existence — time and space. Succession is the simpler of the two facts; an unvarying contact, accompanied with a move- ment, is enough for that. But co-existence is highly complex. The chief points involved in it are those now mentioned, — a series of contacts, and the inversion of the series by an inverted movement. The repetition of these, with the same mental effects, constitutes that notion of permanence, or of f]xity of arrangements, implied in the object world, the universe as co-existing in Space. By drawing the hand over a surface, as, for example, twelve inches of wire, we have an impression of the quality of the surface, and also of its length. On transferring the hand to another wire thirty-six inches long, the increased sweep necessary to reach the extremity is the feeling and the measure of the increased extent. By practising the arm upon this last wire, we should at last have a fixed impression of the sweep necessary for a yard of length, so that we could say of any extended thing, whether it was within or bej^ond this standard. Nay, more, whenever anything brought up a yard to our recollection, the material of the recollection would be an arm impression, just as the material of the recollection of greeiniess is a visual impression. If we pass from length to two dimensions, — as, for example, the surface of a pane of glass, — -we have only a greater com- plexity of movement and of the corresponding impression. Moving in one direction, we get the length ; in the cross direc- tion, we bring other muscles into play, and get an impression of movement on a different portion of the moving system. In this way, we should have the impression of a right angle, or a builder's square. The full impression of the pane of glass would arise through movements from side to side over its whole length, or from movements round the edge and several times across, such as to leave behind the feeling of a possibility of finding contact anywhere within certain limits of length and breadth. In this embodiment, and in no other that I know of, would an extended surface be conceived by the mind through muscularity and touch. (The effect of vision will be afterwards discussed.) '200 SENSE OF TOUCH. A cubical block, exemplifying all the three dimensions of solidity, presents nothing radically new. An additional direction is given to the hand, and an additional class of muscles are brought to contribute to the feeling. The move- ment must now^ be over the length, over the breadth, and over the thickness, and the resulting impression will be a complication of the three movements. To get a hold of the entire solidity, it is necessary to embrace all the surfaces one after another, — which makes the operation longer, and the notion more complex and more difficult to retain. But the resulting impression, fixed by being repeated, is of the same essential nature as the notion of a line or a superficies ; it is the possibility, the potentiality, of finding surface in three different directions within given limits. A cubical block of one foot in the side means that, commencing at an angle, and going along one edge, a foot range may be gone over before the material ceases ; that the same may then be done across, and also downwards ; and that, between every two edges, there is an extended resisting surface. The multiplying of points of contact, by our having a plurality of fingers, very much shortens the process of acquiring notions of surface and solidity. In fact, we can, by means of this plurality, come to measure a length without any movement ; the degree of separation of the fingers, made sensible by the tension of their muscles, being enough. Thus, I can appreciate a distance of six or eight inches by stretching the thumb away from the fingers, as in the span of the hand. By keeping the fingers expanded in this way, so as to enj brace the breadth of an object, and then drawing the hand along the length, I can appreciate a surface by a single motion combined with this fixed span of the thumb and fingers. I may go even farther. By bringing the flexibility of the thumb into action, I can keep the fingers on one surface and move the thumb over another side, so as to have a single impres- sion corresponding to solidity, or to three dimensions. We are, therefore, not confined to one form of acquiring the notion, or to one way of embodying it in the recollection ; DISTANCE — DIRECTION — SITUATION. 201 we have many forms, which we come to know are equivalent and convertible, so that where we find one, we can expect another. But the most perfect combination of perceiving organs is the embrace of the two hands. The concurrence of the impressions flowing from the two sides of the body, produces a remarkably strong impression of the solidity of a solid object. The two separate, and yet coinciding, images support one another, and fuse together in such a way as make the most vivid notion of solidity that we are able to acquire by means of touch. The parallel case of the two eyes is equally striking. The notion of solidity thus acquired is complex ; being obtained through a union of touch and muscularity, and combining perception of surface with perception of extended form. Space, or unoccupied extension, is movement, in vacuo, from one fixed point to another : by the inverted operation, and by repetition giving the same contacts, this is considered to mean extension (as opposed to mere sequence in time). Empty space means the power of movement without contact or resistance, except at the extreme terms. Resistance and empty space are correlatives. In passing from the sense of the resisting to unresisted movement, we make the transition that develops the two cognitions of Body and of Space, under the common object property of Extension. 13. Distance, direction, and situation, when estimated by touch, involve, in the very same manner, the active organs ; the tactile sensations merely furnishing marks and starting- points, like the arrows between the chain-lengths in land- measuring. Distance implies two fixed points, which the touch can ascertain and identify ; the actual measurement being by means of the sweep of the hand, arm, or body, from the one to the other. Direction implies a standard of reference : some given movement must fix a standard direction ; and movement, to or from that, will ascertain any other. Our own body is the most natural starting-point in counting direction ; from it, we measure right and left, back and fore. For the up and down direction, we have a very impressive 202 SENSE OF TOUCH. lead ; this being the direction of gravity. When we support a weight, we are drawn downward ; when not sustaining the arms by voluntary effort, they sink downward ; when our support gives way, the whole body moves downward. Hence, we soon gain an impression of the downward movement, and learn to recognize and distinguish this from all others. If a blind man is groping at a pillar, he identifies the direction it gives to his hand as the falling or the rising direction. Circumstances do not, perhaps, so strongly conspire to impress the standard directions of right and left ; but there is an abundant facility in acquiring them too. The right deltoid muscle is the one chiefly concerned in drawing the right arm up and away from the body ; and, without our knowing any- thing about this muscle, we yet come to associate the feeling of its contraction with a movement away from the body to the right. All directions that call forth the play of the same muscles, are similar directions as respects the body ; different muscles mean different directions. The great pectoral bringing the arm forward, the deltoid lifting it away from the side, the trapezius drawing it backward, indicate to our mind so many different positions of the guiding object ; and we do not confound any one with the others. We learn to follow the lead of each of these indications ; we make a forward step to succeed the contraction of the pectoral, a step to the right the deltoid, a step backward the trapezius. Situation, or relative position, is known, if distance and direction are known. The idea of position implies three points. Two points might give extension ; but relative position implies that we pass from A to B, from B to C, and from A to C. Such movements, often repeated, both in the direct and in the inverse order, impart the idea of permanent co-existence in relative position, which amounts to an expe- rience of Extension. The multiplication of these is the enlargement of our education in the co-existing and extended, from which, at last, by an exercise of abstraction, we rise to the notion of Space or Extension in general. Form or shape is determined by position. It depends FORM. 203 upon the course given to the movements, in following the outline of a material body. Thus we acquire a movement corresponding to a straight line, to a ring, an oval, etc. This is purely muscular. The fixed impressions engrained upon the organs, in correspondence with these forms, have a higher interest than mere discrimination. We are called upon to reproduce them in many operations — in writing, drawing, modelling, etc. ; and the faculty of doing so will depend, in great part, upon the hold that they have taken upon the muscular and nervous mechanism. The suscepti- bility to impressions necessary to draw or to engrave skilfully, and the retentiveness of them, are partly muscular endow- ments. 14. So much for the qualities revealed to us by touch, whether alone or in conjunction with movement. The accompaniment of activity belongs to every one of the senses ; it serves to bring about, or increase, the contact with the objects of the sense. There is, in connexion wdth each of the senses, a particular verb, or designation, implying action: to taste implies the movement for bringing the substance upon the tongue ; to smell, or to snv,ff, means an active inhalation of the odorous stream ; to feel signifies the move- ment of the hand or other organ over the surface in search of impressions ; in like manner, to hear and to see are forms of activity. In the cases of taste and smell, the action does not contribute much to the sensation or the knowledge ; in the three others (two especially), it is a principal element; since, in all of them, direction and distance are essential parts of the information. Now, since movement is required to bring objects wdthin reach, the value of any of our senses will depend very greatl5- upon the activity of the organs that carry the sensitive surface, — the tentacula, so to speak. This activity grows out of the muscular and nervous energy of the frame, and not out of the particular endowment of the sensitive part. It is a voluntary exertion, at first spon- taneous purely, always spontaneous in some degree, but linked to, and guided bv, the sensibilitv- The flush of 204 SENSE OF HEARING. activity lodged in the arm and fingers is the first inspiration towards obtaining impressions of touch ; the Hking or dis- liking for the impressions themselves comes in to modify and control the central energy, and to reduce handling to a system. 15. Touch being concerned in innumerable handicraft operations, the improvement of it, as a sense, enters largely into our useful acquisitions. The graduated application of the force of the hand has to be ruled by touch ; as, in the potter with his clay, the turner at his lathe, the polisher of stone, wood, or metal, the drawing of the stitch in sewing, baking, taking up measured quantities of material in the hand. In playing on finger instruments, the piano, the touch must measure the stroke or pressure that will yield a given effect on the ear. 16. The observations made on persons born blind have fur- nished a means of judging how far touch can be a substitute for sight, both in mechanical and in intellectual operations. These observations have shown, that there is nothing essen- tial to the highest intellectual processes of science and thought that may not be attained in the absence of sight. The integrity of the moving apparatus of the frame renders it possible to acquire the fundamental notions of space, magnitude, figure, force, and movement, and, through these, to comprehend the great leading facts of the outer world as taught in mathematical, mechanical, or physical science. 17. The skin is liable to feelings not produced by an external contact, but resembling what would arise from and suggesting those particular agencies to the mind. These are called ' subjective sensations '. The tiugling of a limb asleep, formication, or a sensation as of the creeping of insects, heat, chilliness, etc., are examples. SENSE OF HEARING. This sense is more special and local than the foregoing, but agrees with Touch in being a mechanical sense as dis- tinguished from the chemical senses — taste and smell. THE EAR. 205 1. The objects of hearing are material bodies in a state of tremor, or vibration, brought on when they are struck, — which vibration is communicated to the air of the atmosphere, and is thereby propagated till it reach the hollow of the ear. All bodies whatever are liable to the state of sonorous vibration ; but they differ very much in the degree and kind of it. The metals are the most powerful sources of sounds — as, for example, in bells ; after metals come woods, stones, earthy bodies. A hard and elastic texture is the property needed. Liquids and gases sound very little, unless impinged by solids. The howling and rustling of the wind arise from its playing upon the earth's surface, like the yEolian harp. The thunder is an example of a pure aerial sound; the effect, great as it is, being very small in comparison with the mass of air put in agitation. It belongs to the science of Acoustics to explain the pro- duction and propagation of sound, and the forms of sounding instruments of all kinds. Here we are considering the effects, and not the instruments of sound. .2. The organ is the Ear. ' It is divisible into three parts — the external ear, the tympanum or middle ear, and the labyrinth or internal ear ; and of these, the two first are to be considered as accessories to the third, which is the sentient portion of the organ.' The external ear includes ' the pinna — the part of the outer ear which projects from the side of the head — and the meatus or passage which leads thence to the tympanum, and is closed at its inner extremity by the membrane interposed between it and the middle ear (membrana tympani)'. ' The tympanum, or drum, the middle chamber of the ear, is a narrow irregular cavity in the substance of the temporal bone, placed between the inner end of the external auditory canal and the labyrinth. It receives the atmospheric air from the pharynx through the Eustachian tube, and contains a chain of small bones,, by means of which the vibrations, communicated at the bottom of the external meatus to the membrana tympani, are conveyed across the cavity to the internal ear, the sentient part of the organ. 206 SENSE OF HEAEING. The tympanum contains likewise minute muscles and ligaments which belong to the bones referred to, as well as some nerves which end within this cavity, or only pass through it to other parts.' As to the ca\aty of the tympanum, I shall content myself with quoting the description of the principal boundaries, whereby it connects itself with the outer and inner portions of the ear, and which are, therefore, the main links in the line of communication from without inwards. The outer boundary, formed by a thin semi-transparent mem- brane, the niembrana tympani, which may be seen by looking into the ear, ' is nearly circular, and is slightly concave on the outer surface. It is inserted into a groove at the end of the passage of the outer ear, and so obliquely that the membrane incUnes towards the anterior and lower part of the canal at an angle of 45°. The handle of one of the small bones of the tympanum, the malleus, descends between the middle and inner layers of the membrane to a little below^ its centre, and is firmly fixed to it ; and as the direction of the handle of the bone is slightly inwards, the outer surface of the membrane is thereby rendered concave.' The inner wall of the tympanum, which is formed by the outer surface of the internal ear, is very uneven, presenting several elevations and foramina. The foramina or openings are two in number, — the oval foramen (fenestra ovalis), and the round or triangular opening (fenestra rotunda). Both are closed with membranes, which render the inner ear, with its containing liquid, perfectly tight. To one of them, the oval foramen, a small bone is attached ; the other, the round foramen, has no attachment. These two openings are the approaches to the internal ear, and through them lies the course of the sonorous vibrations in their progress towards the auditory nerve. The small bones of the tympanum are named from their appearance as follows (beginning at the outermost) : the malleus, or hammer, attached to the membrane of the tympanum ; the incus, or anvil ; and the stapes, or stirrup, which is fixed to the oval opening in the inner ear, called the fenestra ovalis. The incus is thus inter- THE LABYRINTH. 207 mediate between the other two ; and the result of the whole is, ' a species of angular and jointed connecting rod between the outer and inner walls of the tympanic cavity, which serves to communicate vibrations from the membrana tympani to the fluid contained in the vestibule of the internal ear '. There are certain small muscles attached to those bones, for the regulation of their movements. The internal ear, or labyrinth, ' which is the essential or sensory part of the organ of hearing, is contained in the petrous portion of the temporal bone. It is made up of two very Fig. 12.* Right bony labyrinth, viewed from the outer side (after Sommerring). Fig. 13. t View of the interior of the left laby- rinth (from S'Jmmerring). "A. 2? . T" * The specimen here represented is prepared by separating piecemeal the looser substance of the petrous bone from the dense walls which immediately enclose the labyrinth : — 1. The vestibule. 2. Fenestra ovalis. 3. Superior semicircular canal. 4. Horizontal or external canal. 5. Posterior canal. . . . Ampullae of the semicircular canals. 6. First turn of the cochlea. 7. Second turn. 8. Apex. 9. Fenestra rotunda. — The smaller figure in outline below shows the natural size. t The bony wall of the labyrinth is removed superiorly and externally : — 1. Fovea hemi-elliptica. 2. Fovea hemispherica. 3. Common opening of the superior and posterior semicircular canals. 4. Opening of the aqueduct of the vestibule. 5. The superior, 6, the posterior, 7, the external semi- circular canals. 8. Spiral tube of the cochlea (scala tympani). 9. Opening of the aqueduct of the cochlea. 10. Placed on the lamina spiralis in the scala vestibuli. 208 SENSE OF HEAEING. different structures, known respectively as the osseous and membranous labyrinth.' ' (1) The osseous labyrinth is lodged in the cancellated struc- ture of the temporal bone, and presents, when separated from this, the appeai'ance shown in the enlarged figure. It is in- completely divided into three parts, named respectively the vestibule, the semicircular canals, and the cochlea. They are lined throughout by a thin serous membrane, which secretes a clear-fluid. ' (2)*^he memhranous labyrintli is contained within the bony labyrinthXand, being smaller than it, a space intervenes between the two, whiq^ is occupied with the clear fluid just referred to. This structure supports the numerous minute ramifications of the auditory nerve, and encloses a liquid secretion.' The minute anatomy of these parts I must pass over. The vestibule is the central chamber of the mass, and is the portion of the labyrinth turned towards the tympanum, and containing the cavities of communic9;tion already described. The semicircular canals are three bony tubes, situated above and behind the vestibule, into which they open by five apertures ; each tube being bent, so as to form the greater part of a circle. The cochlea is a blunt cone, having its surface ' marked by a spiral groove, which gives to this part of the labyrinth somewhat of the appearance of a spiral shell — whence its name'. Its interior is a spiral canal divided into two by a thin partition, deficient at the apex of the cochlea. The canal opens freely into the cavity of the vestibule. ' Within the osseous labyrinth, and separated from its lining membrane by a liquid secretion, is a membranous struc- ture, which serves to support the ultimate ramifications of the auditory nerve. In the vestibule and semicircular canals, this membrane has the form of a rather complex sac, and encloses a fluid called the endolymph ; in the cochlea, the analogous struc- ture merely completes the lamina spiralis (the partition of the cochlea), and is covered by the membrane which lines the general cavity of the osseous labyrinth.' WAVES OF SOUND IN THE EAR. 209 The labyrinth is thus to be considered as a comphcated chamber full of liquid, containing, also, a membranous expansion for the distribution of the nerve of hearing. Let us, next, advert to the action of these different parts in producing the sensations of sound. 3. The waves of sound enter the passage of the outer ear, and strike the membrane of the tympanum. The structure of the outer ear is adapted to collect and concentrate the vibrations like an ear-trumpet. The form of the shell gives it a reflecting surface for directing the sound inwards ; while the passage is believed to increase their intensity by reson- ance. Eeaching the membrane of the tympanum, the beats communicate themselves to its surface and set it vibratingf, — which is done all the more easily that the membrane is very thin and light m its structure. Experiments have shown, that the only means of receiving with effect the vibrations of the air is to provide a thin stretched membrane of this nature. The vibrations of the membrane are communicated to the chain of small bones traversing the middle, ear, and connected through the oval foramen with the enclosed liquid of the inner ear. By these means, a series of beats are imparted to the liquid, which diffuse themselves in waves all through the passages of the labyrinth, and operate b}' compressing the membranous labyrinth, and, through it, the embedded fibres of the auditory nerve, which compressions are the immediate antecedent of the sensation of hearing. The character of the sensation will, of course, vary with tlie character of the waves, according as they are violent or feeble, quick or slow, simple or complex, and so forth, ^k^ There is little difference of opinion as to the general course of the action now described. The transitions have all been imitated by experiments, and it has been found that the arrangement is a good one for bringing about the ultimate effect, namely, the gentle compression of the filaments of the nerve of hearing. No other medium could serve the final contact so well as a liquid ; but, in order to impress the liquid itself, an intermediate apparatus between it and the air is 14 210 SENSE OF HEARING. requisite. This intermediate apparatus is solid, and com- posed of two parts : the first a light expanded inembrane, susceptible to the beats of the air ; the second firm and com- pact (the chain of bones), to produce a sufficiently powerful undulation in the liquid. The membrane once affected is able to communicate vibrations to the bones ; and the last of the chain, the stapes, is able to impress the labyrinthine fluid. So far the process has been rendered sufficiently intelligible. The first great difficulty tliat meets us in this action is the conveyance of a complication or plurality of sounds through a single line of communication. It is well known that we can hear, at the same instant, a considerable number of simultaneous sounds. The power is not absolutely unlimited ; still, when we are listening to a full band, we seem to be able to take in a very marked plurality of sonorous effects at one and the same instant of time. Now, the chain of bones in the middle ear is equivalent to a single rod of communication. We cannot suppose that there is a subdivision or a plurality of lines in the bony chain ; the whole must be considered as simply one path of transmission. The solution of this difficulty is considered to be the follow- ing : — Two separate sonorous waves striking the tympanum to- gether are fused into one complex or compound wave. The chain of bones in its vibration takes on the character of this compound, and imparts it to the fluid of the labyrinth, in which it is pro- pagated in the same form to the sensory surface in contact with the nerve of hearing. The supposition of a combined simultane- ous sound may be extended to a much greater plurality of simple effects : the resulting compound wave can accommodate its form so as to answer to very high complications. The hypothesis now stated requires to be completed by the further assumption that, at some point in the transmission of the complex wave, a means is found of analyzing or resolving the complication into its primary elements as they separately affected the membrane of the tympanum. It is believed that such an apparatus exists in the membranous labyrinth, and, more par- ticularly, in the minute microscopical structures of the so-called auditory epithelium — including the rods of Corti and the adjoin- RESOLUTION OF THE COMBINED WAVE. 211 ing hair cells in more immediate connexion with the ramifications of the auditory nerve. There is experimental proof that such an analysis of a combined wave is a possible fact. What is required is, that certain parts of the surface impinged upon by the complex vibration should be so constituted as to respond individually to tbe simple sounds and to no others. In this way, if we suppose a structure made up of such parts as would give each a response to some single item of the complex wave, these parts would be affected accordingly, and the separate reproduction of the original elements would be accomplished. So far, the matter appears plain. There still remains a diffi- culty that cannot at present be surmounted. The supposition requires, for its complete fulfilment, that there should be, in the auditory surface, the elements distinctively susceptible of all the various modes of sonorous pitch that the ear is capable of dis- criminating. When we regard the mere number of the elemen- tary constituents of that surface — amounting to tnany thousands, — the capability of varied adaptation to sounds may seem to be very great. What is not so easy to account for is the structural distinctiveness of those minute rods and hair cells that would be required to correspond to the whole range of the musical scale of (say) seven octaves. This is a problem for acoustic research ; and, at present, the resources of the science are unequal to its solution.* There are three muscles in the interior of the tympanum attached to the small bones. The largest, called tensor tyrrvpani, is inserted in the malleus, and its direction is such * The Edison Phonograph demonstrates how the utmost complexity of sonorous vibrations may be transmitted by a rigid needle, registered on wax in a linear tracing of ever-varying depth and lateral direction ; and then reproduced by a reversal of the steps taken in making the first record. A line is thus capable of recording the resultant of the diaphragm's (or drum) vibrations. This would justify one in suggesting that the resultant com- municated to the endolymph through the rigid chain of bones may be equally simple, the direction of the liquid vibrations affecting the nerve endings in special ways. It is thus conceivable that the enormous complexity of orchestral sounds is reduced to a simple resultant, before affecting the auditory nerves at all. The problem of structural complexity in the ear would then reduce itself to accounting for the reception and selection of stimuli that vary, not in complexity, but in intensity and direction. 212 SENSE OF HEAEING. as to draw inwards, and tighten the membrane of the tym- panum. The second, kuxdor tympani, also inserted in the malleus, is supposed to have the action indicated by the name ; but its muscular character has been doubted : the membrane of the tympanum would relax by mere elasticity, when the action of the tensor muscle is remitted. The third mus-cle is the stapedius, attached to the stapes, and seeming to govern the contact of that bone with the mem- brane of the oval foramen ; the tensor tympani concurring with it to tighten the membrane. It has not been fully ascertained on what occasions and with what effect the tensor tympani is brought into play. The only distinct observation on the matter is that made by Wollaston, — namely, that, when the membrane of the tympanum is. stretched, the ear is rendered less sensible to grave sounds, such as the deep notes of the organ, or the sounds of thunder and cannon. If, therefore, the ear is exposed to very intense sounds of the deep kind, such as the firing of artillery, the tensor tympani coming into play would in some measure deaden the effect. The action would make little or no difference to the hearing of acute somids, such as the sharp notes of a call-whistle. Probably, these muscles are excited by the reflex action of the sounds ; possibly, also, they may be of the voluntary class, — that is, they may come into play in the voluntary acts of listening and of preparing the ear to resist loud sounds. The only circumstance assignable as determining the reflex action of the tensor tympani is simply the intensity of the sound. We may suppose that every sound whatever brings on a reflex action to stretch the membrane, and the stronger the sound the greater the action. When sounds are too loud and of the grave kind, this tension mitigates them; when too loud and acute, it either has no effect, or makes the evil worse. ' Dr. Wollaston performed many experiments upon the effects of tension of the membrana tympani, and he found that deafness to grave notes was always induced, which, as SWEET SOUNDS. 213 most ordinary sounds are of a low pitch, is tantamount to a general deafness. Shrill sounds, however, are best heard when the tympanic membrane is tense. Miiller remarks, and we have frequently made the same observation, that the dull rumbling sound of carriages passing over a bridge, or of the firing of cannon, or of the beating of drums at a distance ceases to be heard immediately on the membrana tympani becoming tense ; while the treading of horses upon stone pavement, the more shrill creaking of carriages, and the rattling of paper, may be distinctly heard ' (Todd and Bowman, vol. ii. p. 95). 4. Passing now to Sounds considered as sensations, we may distinguish these into three classes. The first comprises the general effects of sound as determined by QuaHty, Inten- sity, and Volume or Quantity, — ^to which all ears are sensitive. The second class includes Musical sounds, — for which a susceptibihty to Pitch is requisite. Lastly, there is the sensibility to the Articulateness, Distance, and Direction of sounds, — which are the more intellectual properties. 5. Sweetness. — Under the head of Quality, the terms sweet, rich, mellow, are appHed to the pleasing effects of simple sounds. Instruments and voices are distinguished by the sweetness of their indi\adual tones : there is something in the material and mechanism of an instrument that gives a sw^eet and rich effect, apart altogether from the music of the airs performed upon it. Other instruments and sounds have a grating,- harsh, unpleasant tone, like bitterness in taste, or a stink in the nostrils. Some substances, by their texture, have a greater sweetness of note than others. Thus, silver is distinguished among the metals ; and glass is, also, remarkable for rich, meliow tones. The researches of Helmholtz and others seem to establish the fact that the differences of sounds as regards Sweetness (with its opposites), Timbre, and Vowel Quality, are owing to the combi- nation of the principal tone of each with a number of ocer-tones ; which combinations are susceptible of great variety. So strong is the tendency of sounding bodies to yield these over-tones — a 214 SENSE OF HEARING. vibrating string neariy always vibrates in fractions, as well as in its \yliole length, — that pure tones, although experimentally pro- ducible, are scarcely known to us at all. Tones very nearly pure arise from wide-stopped organ pipes. The effect of these on the ear is mellow, but insipid : they are intermediate between the sweet and the harsh. According to this view, the sweetness, even of an individual sound, is a harmony : the ground tone is combined with over- tones, in a pleasing concord. A harsh grating sound is a combi- nation of dissonant tones. Noise, as opposed to the sweet or the melodious, is dissonance. On this theoretical basis, the primary division of sounds would be, — Simple sounds, Sw^eet combinations or concords, and Harsh combinations or discords. But, as simple sounds are practically non-existent, we may still abide by the threefold classification in the text, — namely, (1) Sw^eetness and Harshness, (2) Intensity, and (3) Volume. The second and third properties. Intensity and Volume, are important modifications of sound whatever be the degree of sweetness or of harshness ; and they give a character to such as belong to neither extreme. The sensation of the sv^eet in sound I have characterized as the simple, pure, and proper pleasure of hearing ; a pleasure of great acuteness, but of little massiveness. The acuteness of it is proportioned to the rank of the ear as a sensitive organ, or to the susceptibility of the mind to be stirred and moved through the channel of hearing. There is a great superiority in the endurableness of sweet sounds, over the sweet of the inferior senses. In Touch, the distinction exists, in the comparison with Taste and Smell; in Hearing, there is a further progress ; and we shall have to note the crowning pitch of that important property when we come to the sense of Sight. By virtue of this fact, we can obtain from sight and hearing a larger amount of enjoyment within the same degree of fatigue or exhaustion, or before reaching the point of satiety. Hence, one reason for terming these the ' higher senses '. The persistence in the intellect, which governs the ideal continuance and reproduction of the pleasures and pains of LOUDNESS. 216 sound, is of the same high order, and probably grows out of the same fundamental superiority of the sense. The opposite of sweetness is described by the epithets harsh and grating, and is the characteristic pain of hearing. But, in accounting for the extremely painful sounds, we must not confine ourselves to the fact of dissonance. /^>^ 6. Intensity, Loudness. — Sounds are more or less faint or loud. A gentle or moderate sound, neither sweet nor harsh, is agreeable, in stillness, simply as a sensation, and under the conditions wherein stimulation, as such, is pleasurable. According as the loudness of a somid increases, so does the stiiuulation. The effect, at a given point, takes the character of pungenc}^ — like the action of ammonia on the nose, or a smart stroke on the skin. A loud speaker is exciting. The rattle of carriages, the jingle of an iron work, the noise of a cotton mill, the ringing of bells close to the ear, the discharge of musketry and ordnance, are all exciting from their in- tensity ; to fresh and vigorous nerves plunged into them after quietness, these noises give pleasure. They may be described, however, as a coarse excitement ; there is a great cost of tear and wear of nerve for the actual satis- faction. The intensity, rising beyond a certain pitch, turns to pain. The screeching of a parrot-house, the shrill barking of the smaller species of dogs, the whistling in. the fingers practised by boys in the streets, the screaming of infants, are instances of painful pungency. The sharping of a saw, and the scratching of a piece of glass, yield an intense shrill note. In most of these cases, we must suppose an element of dissonance, as well as a great and smarting intensity. The only criterion of marked dissonance, as opposed to mere pungency, is the offence given to the ear under all conditions, and not merely under fatigue and exhaustion. The suddenness of sounds, by the abrupt transition, aggra- vates their intensity, on the general principle of Eelativity. If unexpected, they produce the discomposure usually attend- ing a breach of expectation. 216 SENSE OF HEARING. 7. Volume or Quantity. — This means the sound' coming from a sounding mass of great surface or extent. The waves of the ' many-sounding sea,' the discharge of tliunder, the howHng winds, are voluminous sounds. A sound echoed from many sides is voluminous. The shout of a great multitude is impressive from the volume. Grave sounds, inasmuch as they require a larger instrument, are compara- tively voluminous. Whether sounds be sweet or indifferent, their multipli- cation has an agreeable effect on the ear. The sensation is extended in volume or amount without the waste of nervous power accompanying great pungency. Both physically and mentally, these sounds conform to the laws of massive sensation. If a sound is intrinsically harsh or grating, or if painful from intensity, the increase in volume will be an increase of pain, — as in machinery. The braying of the ass combines the harsh and the voluminous. 8. Pitch or Time. — -By pitch is meant the acuteness or graveness of a sound, as determined by the ear, and resolvable into the rate of vibration of the sounding body, or the number of vibrations in a given time. The gravest sound audible to the human ear is, according to Helmholtz, 16 vibrations a second ; the highest audible sound corresponds to 38,000 vibrations a second, — being a compass of eleven octaves. One of the deepest tones in use on orchestra instru- ments is the E of the double bass, giving 41;| vibrations a second. The highest note of the orchestra (D of the piccolo flute) is 4752 vibrations (Helmholtz: TundaWs Lecture)^ on Sound, p. 72). The practical range is thus about seven octaves. At the upper limit of hearing, persons differ as much as two octaves ; the squeak of the bat and the sound of a cricket are unheard by some ears. A sound of uniform pitch is a musical note. In the fact of uniform continuance, there is a special mode of pleasure. It is only such sounds that can be farther combined into musical harmonies. HARMONY AND DISCORD. 217 Although, ill music, less intervals than a semitone are not admitted, the ear can distinguish still smaller differences. A quarter of a tone makes a marked difference to an ordinary ear. A good musician can distinguish two tones whose vibrations are as 1149 to 1145, sounded after each other, and even a smaller difference if they are sounded together. Two pitchforks whose number of vibrations per second are 1209 and 1210, sounded simultaneously, can be distinguished by a first-rate ear. 9. The waxing and leaning of sound. The gradual in- crease or diminution of the hjudncss of a sound, is one of the effects introduced into musical composition, owing to the power it has to impart additional pleasure. The howling or moaning of the wind has sometimes this character, and pro- duces a deep impression upon all minds sensitive to sound. The dying away of sound is especially noted as touching : ' that music hath a dying fall '. It may be, that a muscular feeling enters into this sensation ; the gradually increased or relaxed tension of the muscles of the ear being a probable accompaniment of the increase or diminution of loudness. AVe cannot afhrm, however, that it may not be due to the auditory nerves alone. When the pitch is gradually changed, as well as the degree, we have a further modification intro- duced into musical composition, but apt to degenerate into the ' whine ' or ' sing-song '. In the notes of birds, we may trace this effect ; in the execution of accomplished singers, in the violin and other instruments, and in the cadences of a musical orator, we may likewise observe it. 10. Harmonij and Discord. — The concurrence of two or more sounds may be pleasing or unpleasing, irrespective of their character individually. The pleasurable concurrence is called Harmony. It is dependent upon the numerical relationship of the vibrations of the two sounds. Simple ratios, as 1 to 2 (octave), 2 to 3 (fifth), 3 to 4 (fourth), 4 to 5 (major third), 5 to 6 (minor third), are harmonious in the order stated. All these are admissible in musical composi- tion, and are termed chords. The combination 8 to 9 (a 218 SENSE OF HEAEING. single tone) is a dissonant combination ; 15 to 16 (a semi- tone) is a grating discord. It has already been mentioned that an individual sound whose character is sweetness, is already, as it were, a harmony, or concord of many sounds ; the main tone being combined with over-tones. In music, these sounds are still further combined, according to the general laws of harmony. The pleasure of harmony is a wide-spread fact of the human mind : it extends to sight as well as to hearing, and is not wanting in the inferior senses — w^e may have harmonizing or discordant tastes. In the higher emotions, a concurrence may- be either harmonious or discordant. The foundation of the pleasure is probably the same throughout : it is a general prin- ciple, whereby mental states are regarded as either co-operating or conflicting with each other ; in the one case, economizing nervous power and bringing pleasure, — in the other case, wasting power and causing pain. 11. Timbre.— -This means the difference between sounds, otherwise the same, proceeding from different materials, instruments, or voices. We recognize a qualitative differ- ence between the flute and the violin, or between the trumpet and the clarionet ; we can distinguish between one violin and another, and between different voices sounding the same notes with the same intensity. These differences are now explained by the presence of auxiliary upper tones in all instruments ; which tones vary with the material and the instrument. ' In the piano the six first octaves are heard, not the seventh and ninth ; in the violin the six octaves heard feebly, the other octaves very distinct.' It is supposed that perfectly pure tones, identical as regards pitch and intensity, would be undistinguishable, whatever might be their source. 12. Articulate Sounds. — Of articulate sounds, some have a character so peculiar that our discrimination of them is no surprise. The hissing sound of s, the burring of the r, the hum of the i)i, are well-marked modes of producing variety of effect. We can understand how each should impart a AETICULATE SOUNDS. 219 ditferent kind of shock to the nerve of hearing. So, we can see a reason for distinguishing the abrupt sound f, t, k from the continuous or vocal sounds h, d, and g, and from the same sounds with the nasal accompaniment ni, n, ng. It is not quite so easy to explain the distinction of shock between the labials, dentals, and gutturals ; still, if we compare 'p (labial), with k (guttural), we can suppose that the stroke that gives the k is harder than the other. The vowel sounds are explained by the over-tones (octaves) concurring with each fundamental tone, and vary- ing according to the resonance of the mouth, the form of which is altered for each vowel. AVhen the ground tone is heard nearly alone, the sound has the character of u (full). The has, along with the ground tone, the next octave audibly combined. The a (ah) is characterized by the marked presence of the very high octaves.* The same principle is applied to explain differences in the consonant sounds ; but, as respects these, there are other palpable distinctions, such as we have already alluded to. Some persons are distinguished by their nice discrimination of articulate sounds. If the foregoing theory be correct, a good ear for musical notes should be also a good ear for articulation, seeing that the articulate sounds involve composite musical tones. An ear for pitch is thus the basis both of music and of speech. Strictly speaking, however, this applies only to the vowels. The discrimination of consonants may depend on other qualities of the ear ; a circumstance requiring to be adverted to, seeing that, m * The following is Helinholtz's table for the leading vowel sounds: — Ground Vowel. Tone. 2nd. 3rd. 4th. 5th. Gth. 7th. u (full) strong • — weak — — — — o (oh) strong strong (weak) (weak) — — — e (get) strong middling strong (weak) (weak) — — i (bit) weaker strong (very weak) strong (middling) a (ah) strong (weak) weak middhng stronger stronger stronger ' , ' than 3 and 4. The parentheses denote that the tones they enclose are not absolutely neces- sary to the making of the special vowel-sound. •220 SENSE OF HEAEING. point of fact, the good musical ear is not always a good articulate ear. The sense of Time is not confined to any organ or any class of feelings ; but it may attain to great perfection in hearing. 18. The perception of distance can result from nothing but experience. I quote from Longet. ' As soon as the organ presents a sensibility and a development sufficient for discerning easily the relative intensity of two consecutive sounds, nothing further is necessary in order to acquire the notions of distance and direction of the body from which the sonorous waves emanate. In fact, if a sound is already known to us, as in the case of the human voice, or an in- strument, we judge of its distance by the feebleness of its impression upon the nerve of hearing ; if the sound is one whose intensity, at a given distance, is unknown, as, for example, thunder, we suppose it nearer according as it is louder.' We are apt to mix inferential processes with our judgment of distance. If we are led to imagine that a sound is farther off than it really is, we seem to hear it stronger than it is. Awaking suddenly in the night, we hear a faint noise, and suppose it much louder, our notion of its real distance being for a few moments vague and confused. It being an effect of distance that sounds fade away into a feeble hum, when we encounter a sound whose natural quality is feeble, like the humming of the bee, we are ready to imagine it more distant than the reality. 14. Direction. — -This is a purely intellectual sensation, — in other words, is of importance as leading us to perceive the situation of the objects of the outer world whence the sound takes its rise. The following extract from Longet indicates the kind of experience that gives us the feeling of direction : — ' With regard to the direction of the sonorous waves, we can at present only say, that the knowledge of it is owing to a process of reasoning applied to the sensation. Thus, we hear distinctly a sound emanating from a given point, what- DIRECTION OF SOUNDS. 221 ever be the position of the bead ; but the ear being able to judge of sHght differences in the intensity of sounds, we remark that, in certain positions of the head, the sound seems stronger. We are hence led to place our head in one fixed position as regards the sounding body. But our sight tells what is this direction of most perfect hearing ; and we then apply the observation made on bodies that we can see to those that are not seen.' The combined action of the two ears also favours the perception of direction of sound very materially. A person that has become deaf in one ear is, usually, unable to say whether a sound is before or behind. The change of effect produced by a slight rotation of the head, is such as to indi- cate direction to the mind. For, while the sound becomes more perceptible on one ear — the ear turned to face the object more directly, — -the sound in the other ear is to the same degree obscured. When the head is so placed, after various trials, that the greatest force of sensation is felt on the right ear, and the least on the left, we then infer that the sounding body is away to the right ; when the two effects are equal, and when any movement of the head makes them un- equal, we judge the sound to be either right in front or behind ; and we can further discriminate so as to determine between these two suppositions.* * Accordiug to Ed. Weber, in determining the direction of sounds, we employ the external ear for those coming from above, below, behind, before ; the tympanum for those coming from left to right. He made the following experiments : — The head was inserted in water, the air-passage being filled with air, so that the tympanum was free to vibrate. In that case, the ear recognized the sounds as external to itself, but could distinguish them only as right or left in direction. When, further, the ear itself was filled with water, and the free action of the tympanum arrested, the sense of externality was altogether lost. The feeling was regarded as subjective. It was observed by E. H. Weber, that the uniting of the double sensation fi'om the two ears (analogous to binocular vision) has its limits. If two watches with different rates of ticking are held before one ear, the ear distinguishes the periods when the strokes of the two fall together, and forms to itself a rhythm out of the two series of strokes. If the watches are applied, oue to each ear, the sense of rhythm is lost. The mind can no longer make the combination effected when the two watches are applied separately to the two ears. ^22 ■ SENSE OF SIGHT. The sense of direction is by no means very delicate, even after being educated to the full. We can readily judge whether a voice be before or behind, right or left, up or ■down ; but if we were to stand opposite to a row of persons, at a distance, say, of ten feet, we should not be able, I apprehend, to say which one emitted a sound. This con- fusion is well known to schoolmasters. So, it is a matter of some difficulty to find out a skylark in the air from the sound of its song. 15. The duration of the feeling of an individual beat can be appreciated by noting at what intervals a succession of beats seems an uninterrupted stream of sound. This makes, in fact, the inferior limit of the audibility of sounds. From the experiments of Helmholtz, it would appear that a series of beats begins to be felt as continuous when they number sixteen in a second ; so that the impression of each must continue not less than the sixteenth part of a second. 16. The subjective sensations of the ear are such as buzzing, ticking, and hmnming sounds. They arise from disease of the brain, or the auditory nerve, obstructions in the tympanum and Eustachian tube, etc. SENSE OF SIGHT. 1. The objects of sight include nearly all material bodies. Their visibility depends on their being acted on by Light, — hitherto the most inscrutable of natural agents. Certain bodies, — as the sun, the stars, flame, solids at a high temperature, — give origin to rays of light, and are called self-luminous. Other bodies, as the moon, the planets, and the greater number of terrestrial surfaces, are visible only by reflecting the rays they receive from the self-luminous class. The reflexion of light is of two sorts : mirror reflexion, which merely reveals the body that the light comes from ; and reflexion of visibility, which pictures the reflecting surface. In this last mode of reflexion, the light is broken up and emitted in all directions exactly as from a self- luminous original. Visible surfaces receiving light from TRANSPAEENT AND OPAQUE BODIES. 223 the sun have thus the power of absorbing and re-issuing it, while a mirror simply gives a new direction to the rays. When we look at a picture in a bad light, we find that the rays of reflexion overpower the rays arising from the coloured surface of the picture ; consequently, the picture is imperfectly seen. As regards vision, bodies are either opaque or transparent. There is a scale of degrees, — from the most perfect opacity, as in a piece of clay, to the most perfect transparency, as in air. According as bodies become transparent, they cease to be visible. The transparency of Air is not absolutely perfect ; that is to say, light, in passing through the atmosphere, is to a certuin small extent arrested, and a portion reflected, so as to make the mass faintly visible to the eye. When we look up into the sky through a cloudless atmosphere, all the illumination received beyond the sun's disc is light reflected by the atmosphere itself. Liquids are still less transparent : although they transmit light so as to show objects beyond them, they also reflect a sulBicient portion to be themselves ^dsible. Light falling upon the surface of water is dealt with in three different ways. One portion passes through, a second is reflected as from a mirror, a third very small portion is absorbed and radiated anew, so as to make the surface visible as a surface. The same threefold action obtains in transparent solids, — as glass, crystal, etc. It is to be remarked of solid bodies that they are almost all trans- parent to a certain small depth, — as shown by holding up their plates or laminae to the Hght. Gold leaf, for example, permits the passage of light ; and any other metal, if similarly attenuated, w^ould show the same effect. There is, however, in this case, an important difference to be noted, inasmuch as objects are not distinctly seen, although light is transmitted : hence the name ' translucent ' is applied to the case, to distinguish it from proper transparency. There may be something more than a difference of degree between the two actions. 224 SENSE OF SIGHT. Opaque bodies may diffuse much light or little : some substances, such as chalk and sea foam, emit a large body of light ; charcoal is remarkable for absorbing, without emitting the sun's rays. This is the ordinary, perhaps not the full, explanation of white and black, — the one implying a surface that emits a large portion of the rays of visibility, the other few or none. Besides the difference of action, making white and black, and the intermediate shades of grey, there is a difference in the texture of surfaces, giving birth to what we recognize as Colour. Upon what peculiarity of surface the difference between, for example, red and blue, depends, we cannot at present explain. But this fact of colour is one among the many distinctions presented by the various materials of the globe. Along with colour, a substance may have more or less of the property that decides between white and black, — namely, copiousness of radiation. This makes richness of colour, — as in the difference between new and faded colours, between turkey red and dull brick clay of a similar hue. Some bodies are, further, said to possess Lustre. Mineral bodies present all varieties of light, colour, and lustre ; but the prevailing tint of rocks and soils is some shade of grey. The reddish tint of clays and sandstones is chiefly due to the prevalence of oxide of iron. Vegetation yields the greenness of the leaf, and the variegated tints of the flower. Animal bodies present new and distinct varieties. 2. We come, next, to consider the orcian of sight, — the Eye. ' Besides the structures which compose the globe of the eye, and constitute it an optical instrument, there are certain external accessory parts, which protect that organ, and are intimately connected with the proper performance of its functions. These are known as the appendages of the eye (they have been named likewise ' tutamina oculi'); and they include the eyebrows, the eyelids, the organ for secreting the sebaceous (or oily) matter and the tears, together with the canals by which the latter fluid is conveyed to the nose.' ' The eyebroius are arched ridges, surmounting on each side APPENDAGES OF THE EYE. 225 the upper border of the orbit, and forming a boundary between the forehead and the upper eyehd. They consist of thick integu- ment, studded with stiff, obliquely set hairs, under which lies some fat, with part of the two muscles named respectively the orbicular muscle of the eyehds and the corrugator of the eye- brows.' By this last-named muscle, the eyebrows are drawn together, and at the same time downwards, so as to give the frowning appearance of the eye ; the opposite action of lifting and separating the eyebrows is performed by a muscle lying beneath the skin of the head termed the occipito-frontalis. In regulating the admission of hght to the eye, and in the expres- sion of the passions, these two muscles are dalled into play ; the one is stimulated in various forms of pain and displeasure, the other in an opposite class of feelings. ' The eyelids are two thin movable folds placed in front of each eye, and calculated to conceal it, or leave it exposed, as occasion may require. The upper lid is larger and more mov- able than the lower, and has a muscle (levator palpebrae superi- oris) exclusively intended for its elevation. Descending below the middle of the eye, the upper lid covers the transparent part of the organ ; and the eye is opened, or rather the lids are sepa- rated, by the elevation of the upper one under the influence of the muscle referred to. The eyelids are joined at the outer and inner angles of the eye ; the interval between the angles varies in length in different persons, and, according to its extent (the size of the globe being nearly the same), gives the appearance of a larger or a smaller eye. At the outer angle, which is more acute than the inner, the lids are in close contact with the eye- ball ; but at the inner angle, the caruncula lachrymalis (a small red conical body) intervenes. The free margins of the lids are straight, so that they leave between them, when approximated, merely a transverse chink. The greater part of the edge is flattened, but towards the inner angle it is rounded off for a short space : and where the two differently formed parts join, there exists on each lid a slight conical elevation, the apex of which is pierced by the aperture of the corresponding lachrymal duct ' (Quaiu). The lachrymal apparatus is constituted by the following assemblage of parts, — viz., the gland, by which the tears are 15 226 SENSE OF SIGHT. secreted at the outer side of the orbit ; the two canals, into which the iiuid is received near the inner angles ; and the sac, with the duct continued from it, through which the tears pass to the interior of the nose. The description of these parts needs not be quoted in detail here. Suffice it to say, that the tears are secreted by the lachrymal gland, and poured out from the eyelids upon the eyeball ; the washings afterwards running into the lachrymal sac, and thence by the nose. The parts now dwelt upon are less coucerned in vision, than in expression and other functions auxiliary to vision. Though not directly bearing on the object of the present section, they will be of importance when we come to con- sider the emotions and their outward display. From them, we turn to the ball or globe of the eye. ' The globe, or ball of the eye, is placed in the fore part of the orbital cavity, fixed principally by its connexion with the optic nerve behind, and the muscles with the eyelids in front, but capable of changing its position within certain limits. The recti and obliqui muscles closely surround the greater part of the eyeball ; the lids, with the caruncle and its semilunar membrane, are in contact with it in front ; and behind, it is supported by a quantity of loose fat. The form of the eyeball is irregularly spheroidal'; and, when viewed in profile, is found to be composed of segments of two spheres, of which the anterior is the smaller and more prominent ; hence the diameter taken from before backwards exceeds the transverse diameter by about a line. The segment of the larger sphere corresponds to the sclerotic coat, and the portion of the smaller sphere to the cornea.' , ' Except when certain muscles are in action, the axes of the eyes are nearly parallel ; the optic nerves, on the contrary, diverge considerably from one another, and consequently each nerve enters the corresponding eye a little to the inner or nasal side of the axis of the globe. ' The eyeball is composed of several investing membranes, concentrically arranged, and of certain fluid and solid parts contained within them. The membranes are three in number, an external fibrous covering named sclerotic and cornea, a COATS OF THE EYE. 227 middle vascular and pigmentary, in part also muscular, mem- brane, the choroid and the iris, and an internal nervous stratum, the retina. The enclosed light-refracting parts, also three in number, are the aqueous humour, the vitreous body, and the lens with its capsule.' The conjunctiva is more an appendage of the eye than a portion of the globe. It is a thin, transparent membrane covering only Fig. 14.* 3 n * Horizontal section of the right ej-e, with two of the muscles,— ^the ex- ternal and internal recti, — and the optic nerve, a. Aqueous humour, h. Crystalline lens. c. Vitreous humour. 1. Conjunctiva. 2. Sclerotica. 3. Cornea. 4. Choroid. 5. Canal of Fontana. 6.^Ciliary processes. 7. Iris. 8. Retina. 9. Hyaloid membrane. 10. Zone of Zinn, or ciliary processes of the hyaloid. 11. Membrane of aqueous humour (Wharton Jones, On the Eye). 228 SENSE OF SIGHT. the front or visible portion of the ball, and reflected on it from the interior of the eyehds, of which it is the lining mucous membrane. Over the clear and bulging portion of the eye, it is perfectly transparent, and adheres closely to the surface ; on the parts surrounding the clear portion it is less transparent, and contains a few straggling blood-vessels, which are seen as red streaks on the white of the eye. ' The sclerotic, one of the most complete of the tunics of the eye, and that on which the maintenance of the form of the organ chiefly depends, is a strong, opaque, unyielding, fibrous structure, composed of bundles of strong white fibres, which interlace with one another in all directions. The membrane covers about five-sixths of the eyeball, leaving a large opening in front, which is occupied by the transparent cornea, and a smaller aperture behind for the entrance of the optic nerve. The sclerotic is thickest at the back part of the eye, and thinnest about J of an inch from the cornea. At the junction with the cornea it is thickened.' * ' The cornea is a transparent structure, occupying the aperture left in the fore part of the sclerotic, and forming about one-fifth of the surface of the globe of the eye.' The two together complete the encasement of the eye, and no other portion is employed for the mere purpose of maintaining the form and rigidity of the ball. Spread over the inner surface of the sclerotic, lie two other membranous expansions, likewise termed coats or tunics, but of totally different nature and properties. Next the sclerotic, is the choroid coat, — which is a membrane of a black or deep brown colour, lining the whole of the chamber up to the union of the sclerotic with the cornea, and then extending inwards as a ring stretching across the eye. It, also, is pierced behind by the optic nerve. The choroid coat is an extremely vascular structure — that is to say, it is composed of a dense mass of blood-vessels, which lie in two layers, the outermost of the two being the veins, and the other the arteries. Inside of those two vascular expansions, is the layer containing the black pigment that gives to the coat its colour, and which it is the object of the numerous blood-vessels to keep supplied. The pigment is enclosed in the cells of a membrane, and these cells are packed very closely together, and are about the thousandth part of an inch in diameter. Each cell THE EETINA. 229 has a transparent point in its centre, surrounded by a dark margin. The retina, or the nervous coat of the eye, is placed next the choroid, but does not reach so far forward. If a strong light is thrown upon it through the pupil of the eye, it appears of a reddish colour, which is owing to its blood-vessels. When examined after death, it is pinkish and transparent. In the centre of the retina, and in the line of most perfect vision, is observed an elliptical yellow, or golden yellow, spot, about ^^ of an inch long and J^ jvide, in the middle of which is a dark depression called by the discoverer, Scemmerring, the central hole. It is not a hole, but a thinner portion of the retina. About ^V to ^V of an inch from the inner or nasal side of the yellow spot, is a flattened circular papilla, corresponding with the place where the optic nerve pierces the choroid coat. The retina consists of several layers. Beginning at the inside, which is in contact with the vitreous humour, we find a transparent membrane called the limiting membrane, whose thickness does not exceed — i — of an inch. Next are the o ramifications of the optic nerve, the fibres being arranged in fine meshes, and wanting the double outline. These fibres are exceedingly minute ; the average diameter is not more than the oi' . ^\, ,. of 3,n inch ; while some are less than the 4 of an inch in thickness. Within the fibrous layer, is a layer of nerve cells or vesicles, resembling the vesicles that make up the grey substance of the brain. These are most abundant in xhe hinder or central parts of the retina : they vary from the -^QQ to the Y5V0 of ^^^ inch in diameter. Then comes a still more complicated layer, called the yramdar and fibrous layer, which constitutes the link of connexion between me retina and the choroid coat. It is made up of two distinguishable layers of little grains or nuclei, and a number of very fine filaments, with a direction perpendicular to the retina. At their outei* connexion, these filaments are the Q^^jyij to the 4(7^00 of an inch in diameter; at their inner connexion with the fibres of the optic nerve, they»are from the ^^l^ ^ to the — - — of an inch in diameter. The 80000 120000 inner of the two layers, making up the granular and fibrous layer, immediately adjoins the choroid, and is called the colunmar or bacillar layer, being made up of closely-packed perpendicular ■230 SENSE OF SIGHT. rods, transparent and colourless, about 3-775-0 '^^ ^^ ^^'^^^ "^ length, and i of an inch in thickness. Interspersed with these are a ^ larger rods called cones, -^-- of an inch in diameter.* Each pigment cell of the choroid receives as many as six or eight of the cones, with a larger number of the smaller rods grouped round them. They are connected with the other parts of the retina by the fine perpendicular filaments. 'We may then consider the retina as made up of three main layers of cells : (1) the rods and cones with the outer nuclear layer, (2) the cells forming the inner nuclear layer, and (3) the ganglionic cells with the optic iibres. On theoretical grounds we may conclude that these three layers are functionally continuous, that changes set going in the (inner limbs of the) rods and cones sweep through the inner nuclear layer, and issue along the fibres of the optic nerve as neiTOUs impulses ; but, with at least our present knowledge, we cannot demonstrate a structural continuity between them. Two conspicuous breaks occur at the two molecular layers. We can trace the rod fibres and the cone fibres to the outer molecular layer, and there we lose them. We can trace the optic fibres through or apart from the ganglionic cells to the inner moleciilar layer, and there we lose them too. We can trace the processes of the cells of the inner nuclear layer on the one hand to the inner and on the other to the outer molecular layer, and there these too are lost. These two molecular layers, which repeat in the outljdng part of the brain which we call the retina some of the characteristic features of the brain itself, are obviously of no little import- ance in the development of visual impulses ; but for a proper understanding of their nature we must await the results of further inquiry. At present all we can perhaps say is that each layer consists of a network of fine nervous fibrils embedded in neuroglia, but that, as in corresponding cerebral structures, we cannot accuratelj- distinguish neuroglial from nervous elements, much less trace out the exact disposition of the latter. In the outer molecular layer among the tangle of fibrils, nervous and neuroglial, we may distinguish small branched cells, lying flatwise in the plane of the layer; these are probably neuroglial ceUs whose branched processes become neuroglial fibrils. In the inner molecular laj"er such cells are absent or at least inconspicuous ; the laj'er seems to consist on the one hand of nervous fibrils derived from the branching processes of nerve cells and on the other hand of neuroglial fibrils, all embedded in a peculiar gi'ound-substance which stains deeply with osmic acid, and indeed is of a nature in some respects allied to the medulla of a nerve fibre. ' We have reason to think that the molecular changes which light induces in the inner limbs of the rods and cones difier very considerably in character from the molecular changes in the fibres of the optic nerve which constitute a nervous impulse, and that th? transformation from the one set of changes to the other is effected through some or other of the retinal structures which we have described. But we cannot attribute definite functions to the several elements; and here, as in the case of the brain and spinal cord, we may hesitate to assign too much to cellular elements. We may, perhaps, in con- *The above estimates of size are mostly taken from KoUiker, being transformed from millimetres by dividing by 24 (instead of 25 and a fraction), to keep to round nmnbers. THE YELLOW SPOT. 231 formit}' with what we have urged elsewhere, regard the cells of the ganglionic layer as being largely concerned in nutritive labours, and may even apply the same view to the nuclear layers ; if this be so, no small part of the work of the retina in transforming the first crude effects of the impact of light into true nervous impulses, may be looked upon as being carried out by the tangle of nerve fibrils, in the two molecular layers and elsewhere' (Foster, p. 1202). It is interesting to notice how those several elements are disposed in the yellow spot and its vicinity, where vision is most perfect. From the margin of the spot towards the central hole, the rods of the colmiinar layer, the nuclei resting upon them, and the fibres of the optic nerve, gradually diminish, and at last fade away. On the central hole, nothing is left but the larger rods, or cones, with the fine perpendicular fibres, and the vesicles, which are here closer than anywhere else, there being one for every cone, and the layer being 7 or 8 cells thick. Those elements that thus disappear iu the central hole, are, however, very abundant near the margin of the yellow spot. The smaller rods take the place of the cones, and the fibres of the optic nerve are very abundant and close. Thus, if we take the yellow spot together with its immediate surroundings, we find there the retina most highly developed ; and it is on this part that we can discriminate visible objects with the greatest delicacy. The unequal distribution of the different elements between the outer and inner parts of the yellow spot is remarkable.* * Mr. Herbert Spencer {Psychology, new edition, p. 35) indicates a class of structures, at the extremities of the nerves of sense, as multipliers of distur bailees, or as ser\ang to enhance the efficacy of the peripheral stimu- lation of the nerves. Thus, in touch, the short hairs render the skin more sensitive to contacts ; while the so-called ' little bodies of touch' tend greatly to exaggerate the pressure upon the nerve fibres when the skin is compressed. In the ear, the otolites and minute rods and fibres serve to transform the liquid %abrations into the more energetic vibrations of solids, so as to affect the nerve more powerfully. Finally, in the eye, the lenses concentrate the light upon the retina. The structures at the back of the eye are interpreted on the same prin- ciple of increasing the susceptibility to slight disturbance ; the luminous waves being the feeblest of all known agencies. The fibres of the retina are reduced to the naked core ; the protecting medullary sheath being absent. The light, passing through the transparent retina, affects the more sus- ceptible pigment cells of the choroid coat, whence the disturbance is con- veyed by the rods and perpendicular filaments to the nervous layer of the retina. Lastly, the nervous layer itself consists, not only of fibres, but also of nerve vesicles or corpuscles, which arc much more liable than the fibres to take on molecular disturbance, and originate molecular motions. 232 SENSE OF SIGHT. Before pointing out the different bodies that make up the bulk of the eye, and enable it to act as an optic lens, I must call attention to several other substances of a membranous or fibrous character lying under the cornea and near the junction with the sclerotic coat. The first of these is the ciliary ligament, — a narrow circular band, of a greyish-white colour, close behind the junction above-named. The fore- most margin, the thicker of the two, gives attachment to the circular curtain called the iris. The thinner and pos- terior margin is blended with the choroid coat, which here prolongs itself inwards in a series of radiated folds called the ciliarij processes. The ciliary processes lie behind the iris, and make a black, wrinkled, narrow rim, concealed from external view. ' The iris may rightly be regarded as a process of the choroid ; it is continuous with it, although of a modiiied structure. It forms a vertical curtain, stretched in the aqueous humour before the lens, and perforated for the transmission of light. It is attached all round at the junction of the sclerotic and the cornea, so near indeed to the latter that its anterior surface becomes continuous with the posterior elastic lamina.' ' The anterior surface of the iris has a brilliant lustre, and is marked by lines accurately described by Dr. Jacob, taking a more or less direct course towards the pupil. These lines are important as being indicative of a fibrous structure.' ' When the pupil is contracted, these converging fibres are stretched ; when it is dilated, they ai^ thrown more or less into zigzags. The pupil is nearl^^ circular, and is situated rather to the inner side of the centre of the iris. By the movements of the iris, it is dilated or contracted, so as to admit more or less light to the interior ; and its diameter under these circumstances may vary from about J^ to i of an inch ' (Todd and Bowman, vol. ii. p. 25). The iris is thus to be considered as a muscular structure ; its fibres being of the unstriped variety, or of the kind that prevails among the involuntary muscles, as the muscular fibres of the intestines. It is abundantly supplied with nerves. LENSES OF THE EYE. 233 While the radiating fibres ah-eady described serve to dilate the pupil, a second class of fibres, arranged in circles round the opening, and best seen at the inner margin and behind, operate in contracting it. The action is regulated by the intensity of the light. In the dark, or in a very faint light, the dilating fibres are tense and contracted to the full, making the pupil very wide. The stimulus of light brings the circular or con- tracting fibres into play, and contracts the opening. The changes thus eiTected are useful in adapting the eye to dif- ferent lights, admitting a larger quantity with a feeble light, and a smaller quantity with one that is too strong. AVhen this reflex power of adaptation reaches its limit, and the brilliancy is still too great, we then put forth the voluntary efforts of closing the eye, or of turning the head away from the object. (See Foster, pp. 1162, 1172, 1179.) Behind the ciliary ligament, and covering the outside of the ciliary processes, is a greyish, semi-transparent structure, known as the ciliary muscle. ' It belongs to the unstriped variety of muscle, and its fibres appear to radiate back- wards from the junction of the sclerotic and cornea, and to lose themselves on the outer surface of the ciliary body. The muscular nature of this structure is confirmed by its anatomy in birds, where it is largely developed, as noticed by Sir P. Crampton ' (Todd and Bowman, ii, 27). A peculiar interest has come to attach to this muscle, from its supposed operation in adapting the eye to objects at different distances. Passing now from the coats of the eye to the substance, we find three humours, or transparent masses occupying it in the following order : in the front is the aqveous humour ; next, the crystalline lens ; and backmost the vitreous humour. The aqueous or watery humour is a clear, watery liquid lying under the cornea in front, and bounded behind by the crystalline lens and the folds of the ciliary processes. This humour is very nearly pure water, containing in solution a small quantity of common salt and albumen ; and is enclosed in a membrane, which is in contact with the inner surface of the cornea, in front, and 234 SENSE OF SIGHT. the ciliary processes and lens behind. The liquid is partly before and partly behind the iris. ' The vitreous or glassy humour lies behind the crystalline lens, and occupies the entire posterior chamber of the eye, being about two-thirds of the whole. It consists of a clear, thin fluid, enclosed in a membrane, which membrane not merely surrounds it, but radiates inwards into its substance like the partitions of an orange, so as to make up a half-solid gelatinous body — the vitreous body, or posterior lens of the eye. These partitions are very numerous, and point to the axis of the eye, but do not reach to it ; and, consequently, there is a central cylinder passing from front to back, composed only of the fluid of the body. The form of the vitreous body is convex behind, while, before, there is a deep cup- shaped depression for receiving the crystalline lens. The mem- brane that surrounds it on all sides, as well as entering into the interior, has a twofold connexion in front ; it doubles so as to receive the crystalline lens between its folds, and it unites with the ciliary processes, which surround the lens without reaching its border. Thus the partition, between the aqueous humour in front, and the vitreous humour behind, is made up of three successive portions enclosing one another : the wrinkled black ring of the ciliary processes outermost ; within this, a ring of the doubled membrane of the vitreous humour ; and, inmost of all, the crystalline lens, enclosed between the two folds of the mem- brane. The crystalline lens is a transparent solid lens, — double convex in its form, but more rounded behind than before. It is sus- pended between the aqueous and vitreous humours, in the manner already described. Its anterior convexity approaches very near the curtain of the iris stretched in front of it. The lens is enclosed in a capsule ; and, of this, the front portion is thick, firm, and horny, while the portion on the back is thin and membranous, adhering firmly to the membrane of the vitreous humour. The substance of the lens varies in its character : the outside is soft and gelatinous ; beneath is a firm layer ; and, in the centre, is the hardest part, called the nucleus. It is supphed with blood- vessels in the edges ; but none appear to penetrate within, except in a very early stage of life. It undergoes, altogether, a great change during the development of the individual. In the foetus. MUSCLES OF THE EYE. 235 it is nearly spherical, and not perfectly transparent ; in mature life, it is of the form and character we have described ; while, in old age, it becomes flattened on both surfaces, loses its trans- parency, and increases in toughness and density. Of the six muscles of the eye, four are called recti or straight, and two oUique. The four recti muscles arise from the bony socket in which the eye is placed, around the opening where the optic nerve enters from the brain : they are all inserted in the anterior external surface of the eyeball, their attachments being respectively on the upper, under, outer, and inner edges of the sclerotic. The superior oblique or trochlear muscle arises close by the origin of the superior straight muscle, and passes forw^ard to a loop of cartilage ; its tendon passes through the loop, and is reflected back, and inserted on the upper posterior surface of the eye- ball. The inferior oblique muscle arises from the internal inferior angle of the fore part of the orbit, and is inserted into the internal inferior surface of the eyeball, behind the middle of the ball. The motions of the eyeball that would be caused by the contractions of any of these muscles are not difficult to trace. The inferior muscle, by its contraction, will make the ball revolve so as to look downwards ; the superior straight muscle will make it look upwards. The internal and ex- ternal recti will give it their respective directions, — the one inward, the other outward. The action of the trochlear muscle is pecuHar. Inasmuch as it is reflected backward to be inserted in the globe of the eye, it will turn the eye- ball downwards and outwards ; that is, the eye would, by its action, look obliquely downwards and outwards. The inferior oblique muscle, having its origin in the fore part of the orbit, and its insertion in the inner side of the eyeball, will, by its contraction, also turn the eye upwards and inwards. The following extract froin Foster may help to explain the complications growing out of the difl"erent groupings of 236 SENSE OF SIGHT. the muscles in the various situations assumed by each eyeball : — ' The six muscles therefore would seem to act as three pairs, the superior and inferior rectus, the internal and external rectus, and the inferior and superior oblique, each pair rotating the eye- ball round a particular axis. Calculations based on a careful study of the attachments and directions of the several muscles, and the results of actual observations, show that this is so, and that the movements carried out by the several pairs may be more accurately described as follows. ' The superior rectus and the inferior rectus rotate the eye round a horizontal axis, which may be described as one directed from the root of the nose to the temple ; it is therefore not a line at right angles with the visual axis but one making an acute angle (20°) with such a line. The superior and inferior oblique rotate the eye round a horizontal axis which may be described as one directed from the centre of the eyeball to the occiput ; it again is not a line at right angles to the visual axis, but makes an angle, with such a line, larger (60°) than the similar angle made by the inferior and superior rectus, and turned in a different direction. The internal rectus and external rectus rotate the eyeball round a vertical axis passing through the centre of rotation of the eyeball parallel to the medium plane of the head when the head is vertical ; this therefore is at right angles to the visual axis, and so differs from the other two. ' When we compare the movements thus effected by these several pairs of muscles with the movements which we described above as the ordinary movements of the eye, namely movements of rotation round a vertical and round a horizontal axis both at right angles to the visual axis, we see that it is only the move- ments round the vertical axis which can be carried out by one pair of muscles acting alone, the particular pair being the internal and. external rectus. Neither the horizontal axis of rotation of the inferior and the superior rectus, nor that of the oblique muscles, is placed exactly at right angles to the visual axis ; each of them makes an oblique angle with that axis. Hence when in carrying out the ordinary movements of the eye we rotate the eyeball round the horizontal axis, we do not employ either of CONDITIONS OF VISION. 237 these pairs of muscles alone, but combine them, making use of one muscle of one pair with one of the other. The superior and inferior rectus in moving the visual axis up and down also turn it somewhat inwards, to the nasal side ; but this is corrected if the obhque muscles act at the same time ; and it is found that the rectus superior acting with the inferior oblique moves the visual axis directly upwards, and the rectus inferior acting with the superior oblique directly downwards in a vertical direction ; that is to say the two combinations rotate the eyeball round a horizontal axis at right angles to the visual axis. ' Hence there are only two movements of the eyeball which we can carry out by the help of one muscle alone, namely, that in which we simply turn the visual axis to the nasal side, employing the internal rectus, and that in which we turn it to the temporal side, employing the external rectus, the visual axis in both cases remaining in the same plane, the visual plane. In order to raise or lower the visual axis in the same vertical plane, without- lateral movement, we must use two muscles ; and if we wish to execute an oblique movement combining an up and down with a side to side movement of the visual axis we must employ three of the ocular muscles ' {Phys., p. 1383). 3. Such being the mechanism of the eye, I must now touch briefly upon its mode of acting as the organ of sight. The optical part of the process is well enough understood. When the eye is directed to any object, an image of that object is depicted on the back of the eye, by means of the rays of light entering the pupil, and is duly refracted by the different humours. The precise mode of stimulating the nervous filaments of the retina is not known ; but the pigment cells of the choroid play an important part, being themselves highly absorbent of light : where they are not found, as at the place of entrance of the optic nerve, there is no power of vision (the bhnd spot). In order to perfect vision, the following further conditions are necessary : — (1) A sufficiency of light or illumination in the object viewed. This is an obvious necessity. We judge of the 238 SENSE OF SIGHT. quantity of light present by the power we have of seeing objects distinctly. Some animals can see with much less light than others, and to such the noonday sun must be painful. (2) The formation of the image exactly on the retina, and not before or behind. The focus of the image must coincide with the retina. If this is not the case, the image is indistinct ; the rays of light either do not converge, or have begun to disperse, at the back of the eye. The perfect convergence of the image by the lenses constituting the ball of the eye, depends on the distance of the object, and also, in some degree, on the self-adjustment of the eye. ' As this power of adaptation of the eye itself for vision, at different distances, has its limits, there is in every individual a dis- tance at which he sees most distinctly, and at which the ■focus of the image, formed by the refracting media of the eye, corresponds most accurately with the situation of the retina. This distance may be stated at from five to ten inches, in the majority of individuals. Objects which are too near the eye throw very indistinct images upon the retina ; a slender body, such as a pin, held close to the eye, cannot be seen at all, or produces only an undefined im- pression on the retina. Few persons, on the other hand, are able to read print at a much greater distance than twenty inches.' (3) The third condition of perfect vision is the minute size of the subdivisions of the retina capable of independent sensation. We are sensitive to very minute lines and points ; and there is a limit of minuteness, where a number of distinct lines would seem as one. This is the limit of the optical subdivision of the retina, analogous to the intervals of double sensation in touch. It appears that minuteness of discrimination is aided by the following circumstances : — 1. An intense light will enable a smaller object to be seen. 2. A white picture can be seen smaller than a blue. 3. A line can be seen better than a point of the same diameter. The smallest angle for a round SUPERIOEITY OF THE EYE. 289 body is 20" ; a thread-like object is discernible under an angle of 3"; a glancing wire can impress the eye at an angle of i". According to Weber and Volkmann, two bright lines must be separated at least from tj-oVo ^o t^s-tto ot an inch on the yellow spot to give a double sensation ; which is an estimate quite compatible with the observed minuteness of the fibres and vesicles of the retina, supposing each of these capable of conveying an independent impression to the brain. The power of discrimination diminishes rapidly as the impression recedes from the yellow spot. At a point 60° from the centre of the spot, an object must be 150 times larger, in order to be distinguished. Thus, although the eye can take in a wide field at once, the power of minute observa- tion is confined to a very small part in the centre of the retina.* The great superiority of the eye, as a medium for per- ceiving the outer world, lies in this power of independent sensibility to minute points. I have already adverted to the distinction between the lower and the higher senses in this * Another condition of perfect vision has been suggested by the following experiments of Wundt : — If a small piece of red paper is held before the eye, and then moved to one side without the eye following it, so that the im- pression is made first on the yellow spot, and then on the lateral parts of the retina, the colour is variously seen. To the yellow spot, the paper is red ; as it moves sideways, it becomes darker ; gradually, it assumes a bluish tint, and, at last, it appears perfectly black. Similar variations occur with any other colour, simple or mixed, and also with white, which unites all the colours. The last in the series is, in all cases, black. Whence, it appears that different parts of the retina are differently sensitive to impressions of colour. The variation occurs in the same order in every direction, but with unequal rapidity. The series is passed through quicker, when the object is moved outwards, than when it is moved inwards ; and, also, quicker for the upward than for the downward movement. It does not follow that, in looking at a wide expanse of one colour, we see the gradations of tint in concentric rings. This is only one of many cases where the mind overbears the sense. We have derived our notion of each surface from the way that its parts affect us when brought successively before the yellow spot — the place of minute examination, — and what we seem to see is the habitual effect, rather than the effect at the instant. 240 SENSE OF SIGHT. particular. The nerve of vision must needs consist of a number of independent fibres maintaining their distinctness all the way to the brain, and capable of causing distinct waves of diffusion throughout the entire cerebral mass ; every one of these many thousand impressions varying the mental experience, and originating a distinct volition. We shall probably meet with no fact attesting more conspicuously the complexity, and yet the separateness, of action of the cerebral system. AVe can easily satisfy ourselves of the reason why the cerebral hemispheres should be necessary to vision, considering what is thus implied in every instance of seeing whatsoever. 4. TJie Ada/ptation of the Eye to Vision at Different Distances. — If I see an object distinctly six inches distant from the eye, all objects at a greater distance are indistinct. The image of the near object falls correctly on the retina ; the images of remote objects are formed in front of the retina. By a voluntary effort, I can adapt the eye to see a far-off object with tolerable clearness ; but it then happens that any near body becomes confused. The questions arise — What is the change produced upon the eyeball, in the course of this adaj^tation from near to far, and from far to near ; and what apparatus effects the change ? In seeing close at hand, the crystalline lens becomes thicker and more convex in front ; in seeing at a distance, the surface is flattened. The change of curvature is con- siderable. The centre-point bulges out j^-th of an inch for near vision. A very slight increase takes place in the curvature of the hinder surface. The changes of curvature depend on the action of the ciliary muscle. This muscle contracts for near vision. The effect of the contraction is to draw the choroid membrane forwards, and, by that means, to compress the vitreous humour, which exerts a pressure on the lens, pushing it forwards. At the same time, the muscular fibres of the iris come into play, contracting the pupil and also the outer ADAPTATION OF THE EYE TO DISTANCE. 241 circumference. This brings a pressure to bear upon the lens from before, but not an equal pressure ; it is least at the centre, and greatest towards the edges. Between these two pressures, from behind and before, the lens is bulged out in the middle, and its curvature increased. Thus, for near vision, there is a very considerable muscular action : when looking at anything close, we are conscious of a strain in the interior of the ball. For distant vision, this action is relaxed, and the inherent elasticity of the parts restores the flattening of the lens. Hence, the natural repose of the eye makes the adjustment for a distant prospect.* The eyeball is subject to alteration chiefly for near dis- tances. Between the smallest visible distance (say four inches), and three feet, nearly the whole range of the adjust- ment is gone through. When we compare distant objects of varying remoteness, as, for example, thirty feet with One hundred, or a thousand, very little change is effected on the form of the eyeball, the adjustment then depending on the greater or less convergence of the two eyes. This leads to the subject of binocular vision. 5. Single Vision tvith Two Eyes. Binocular Vision. — Among the questions long discussed in connexion with sight, was included the inquiry, Why with two eyes do we see objects single ? Answers more or less satisfactory were formerly attempted ; but, since the year 1838, an entirely new turn has been given to the discussion. In that year, Professor Wheatstone gave to the Royal Society his paper on Binocular Vision, wherein he described his ' stereoscope,' * The limits of monocular vision are illustrated by the following experi- ment. If a thread is moved against a white wall, and we observe it with one eye through a tube, we can detect a difference when it is moved nearer, but not when it is moved farther away. This is consistent with the circumstance, tViat, in changing to near vision, we cause a muscle to contract, while in changing to a more distant view, tlie proper elasticity of the parts releases an existing contraction. So, under the same circumstances, we may estimate the interval moved over by the thread, when it is brought nearer ; but we can form no estimate of the absolute distance (Wundt). 16 242 SENSE OF SIGHT. or instrument for imitating and illustrating the action of the two eyes in producing single vision. The following quota- tion is from the opening paragraph : — ' When an object is viewed at so great a distance that the optic axes of both eyes are sensibly parallel when directed towards it, the perspective projections of each, seen by each eye separately, are similar, and the appearance to the two eyes is precisely the same as when the object is seen by one eye only. There is in such case no difference between the visual appearance of an object in relief, and its perspective projection on a plane surface ; and hence pictorial representations of distant objects, when those circumstances which would prevent or disturb the illusion are carefully excluded, may be rendered such perfect resemblances of the objects they are intended to represent, as to be mistaken for them ; the Diorama is an instance of this. But this similarity no longer exists when the object is placed so near the eyes that to view it the optic axes* must converge ; and these perspectives are more dissimilar as the convergence of the optic axes becomes greater. This fact may be easily verified by placing any figure of three dimensions — an outline cube, for instance — at a moderate distance before the eyes, and while the head is kept perfectly steady, viewing it with each eye successively while the other is closed. The figure represents the two perspective projections of Fig. 15. /] / / V d \ \ \ \ \ a cube ; a is seen by the right eye, and d is the view presented to the left eye, the figure being supposed to be placed about seven inches immediately before the spectator.' *The optic axis of the eye is the line of visible direction for distinct vision, or a line proceeding from the central point of the retina, and passing through the centres of the lenses of the eye. BINOCULAR VISION. 243 ' It will now be obvious why it is impossible for the artist to give a faithful representation of any near solid object, that is to produce a painting which shall not be distinguished in the mind from the object itself. When the painting and the object are seen with both eyes, in the case of the painting, two similar pictures are projected on the retinae, in the case of the solid object, the pictures are dissimilar ; there is therefore an essential diiference between the impressions on the organs of sensation in the two cases, and consequently between the perceptions formed in the mind ; the painting, therefore, cannot be confounded with the solid object.' Thus, the dissimilarity of the pictures is the chief optical sign of solidity or of three dimensions. The greater the dis- similarity, the more decidedly is a third dimension suggested ; perfect similarity occurs in looking at things very remote, or in examining a surface at right angles to the line of vision, all the parts being equally distant. The stereoscope gives the illusion of solid effect by presenting to the two eyes dissimilar pictures, imitating the natural presentation in the case of an object or a scene unequally removed from the eye. A great difficulty is experienced in explaining binocular vision, through mistaking the exact nature of the effect pro- duced upon the mind by the impression made on the eye on one single occasion. We are apt to suppose that the entire conscious state at any one moment — the full imagery pic- tured to our view — -is determined by the rays affecting the retina at that moment. The truth is, that what rises to the mind on the sight of an outward thing, is an aggregate of past impressions, which the impression of the moment suggests but does not constitute. The education of the sense of sight makes us aware that an identical impression upon both eyes concurs either with great distance, or with mere surface, — that is, with two dimensions only, — there being no inequality of distance from the eye. On the other hand, unlikeness of picture corresponds with the introduction of the element of unequal distance ; and the more this inequality exists, the greater is the dissimilarity. Accordingly, the 244 SENSE OF SIGHT. mind, instead of being perplexed with double images, at once adopts the notion of a single complex object with varying remoteness ; the variation being estimated, among other signs, by this very unlikeness of the pictures. It is immaterial whether the retinal presentations be two, as in binocular vision, or thousands, as in the vision of insects : these presentations are but the hint to a mental construction, representing the unity of the external scene, in its length, breadth, and depth. The question of binocular vision has been, since Wheatstone's time, very largely discussed, and has been made the subject of exceedingly elaborate investigation by means of experiment. It has entwined with itself a number of other profound questions, — such as, the ultimate groundwork of our notions of Space, Solidity, and External Reality.* * For criticism of Wheatstone's theory, see Le Conte, Sight, International Scientific Series, i. p. 145. The following quotation indicates the more modern view, verifiable by simple experiments : — ' All objects or points of objects, either beyond or nearer than the point of sight, are doubled, but differently — the former homonymously, the latter heteronymously. The double images in the former case are united by less convergence, in the latter case by greater convergence, of the optic axes. Now, the observer knows instinctively and tvithout trial [this as against Briicke's theory of incessant unconscious motion between near and far], in any case of double images, whether they will be united by greater or less optic convergence, and therefore never makes a mistake, or attempts to unite by making a wrong movement of the optic axis. In other words, the eye (or the mind) instinctively distinguishes homonymous from heteronjTnous images, referring the former to objects beyond, and the latter to objects this side of, the point of sight ' (Le Conte, Sight, p. 151). A careful measurement of a stereoscopic photograph will show that ' identical points in the foreground are always nearer together than identical points in the backgi'ound ; therefore, when the background is united the foreground is double, and vice versa ' (ib., p. 130). If the stereoscopic photo- graph pictures are transposed, so that left becomes right, and right left, the identical points, formerly near, are now far, and rice versa. On combining with the stereoscope, the perspective is found to be reversed — a soUd becoming hollow, and a hollow solid. If, while still maintaining the transposition, we so converge the eyes by squinting that the original right image falls on the right eye, and the original left on the left eye, a beautifully defined miniature forms between picture and face, and the original perspective is brought out perfectly. Thus, by alternately combining through the stereoscope, which is a means of relaxing the accommodation, and then combining by converging so that the optic axes cross, we may have from the same images, first, the ordmary perspective, and then the reversed perspective. THEORY OF THE STEREOSCOPE. 245 One part of the inquiry has taken the course of considering how far the stimulation of corresponding parts of the two retinas is essential to singleness of vision. The amount of possible correspondence of points identical for the purpose of vision has been exhaustively shown. Only near the centre of vision, in the yellow spot, can there be absolute correspondence of the parts of the two retinas exposed to one and the same object. As we retreat from the centre, the points affected cease to correspond in such a way as to make an absolutely single impression. Hence, if such coiTespondence were indispensable, oui- vision of any object would be single at the point of direct observation, or concentration of regard, while all round would be a mass of double images. Thus, by sensation alone, pure and simple, single vision of any extended surface would be impossible. There must be some way out of this difficulty. The theory of the stereoscope comes to our aid. It must, however, be supplemented by the assumption of a long course of experience, — education, it maj' be, assisted by evolution, — whereby we habitually disregard the actual sensation of the moment and form a judgment wholly at variance with it. We have come to treat the dissimilar pictm-es on the two eyes, when directed upon the same object, as signs of something that we do not see bv direct and immediate vision, but infer as a consequence of in- numerable experiments carried on during our lifetime, and pos- sibly assisted by heredity. Looking down a vista, if we were conscious of the literal result of the binocular sensation, we should treat it as a fiat picture, the centre parts single, the circumferential double all through. In fact, it is, seemingly, not now in our power to realize such an interpretation ; we have been so completely educated into the other view of it. Indeed, so thorough and unvarying is the procedure of the mind in the acquired interpretation, that many have accounted it absolutely instinctive. The whole question of pex'ception of solidity, or three dimen- sions, contains as one of its essential parts this assumption as to the influence of dissimilar pictures in overbearing the primary optical impression that these would produce. Co-operating with this assumption is the influence of the ocular muscles in directing the various movements of both eyes. Much controversy has 246 SENSE OF SIGHT. surrounded this subject likewise. It is a necessary assumption of the theory above stated that the eyes should be in full and various activity, and that the consciousness should participate in the resulting feelings. Not only so, but it is also necessary that other experiences of movement should enter into the education requisite for the mighty transformation that we have described. In speaking of the concurrence of the two eyes in the per- ception of solidity, we have to take notice of the fact that a perfect fusion of the binocular effects, supposed equal for both eyes, is by no means universal. It is not uncommon for one eye to take a lead and to give the position of the object, while the other merely contributes to the perception of solidity. The meaning is this. Suppose the right eye to take the principal share in the picture ; the closing of the left would have no effect upon the visible position, while the closing of the right would shift the position considerably to the right of the field of view. Experiments upon the fusion of colours presented to the two eyes, so that the one eye might see one and the other eye see another, would seem to show that fusion is only occasional ; sometimes the composition of the two colours is affected, and sometimes they still appear separate. 6. Before quitting the consideration of the Eye, I should mention that, the seeing of objects erect hy means of an i7iverted image on the retina, has been conceived as a phenomenon demanding explanation. But, to make this a question at all, is to misapprehend entirely the process of visual perception. An object seems to us to be up or down, according as we raise or lower the pupil of the eye in order to see it ; the very notion of up and down is derived from our feelings of movement, and not at all from the optical image formed on the back of the eye. Wherever this image was formed, and however it lay, we should consider that to be the top of the object which we had to raise our eyes or our body to reach. 7. And, now, as to the sensations, or the proper mental elements of Sight. These are partly optical, resulting from the effect of light on the retina ; and partly muscular, arising through the action of the various muscles. Nearly all sen- sations of sight combine both elements. SENSATION OF LIGHT. 247 8. I shall commence with the sensation of mere Light, and shall take the diffused solar radiance as the leading example. This is one of the most powerful of the simple influences that affect the human sense. Light is eminently a source of pleasure, which rises in degree, within certain limits, in proportion to the abundance of the luminous emanation. The degree is massive or acute, according as the effect proceeds from a diffused surface like the sky, or from luminous points as in artificial illumination. In either case, it is possible to obtain a considerable amount of pleasure from this source. As a cheering influence, light ranks with warmth, alimentation, and pleasant repose. On the principle of Relativity, the full effect is experienced only after confine- ment in the dark. The speciality of the pleasures of light is their endurable- ness. The influence, although powerful, is yet gentle ; it does not exhaust the nerves so rapidly as sweet tastes, pungent odours, or loud sounds. This is the great distinction of the sense of sight. Hearing also ranks high in the same property ; but we must still assign to it, as a rule, the second place. One of the things understood by the term ' refine- ment,' as applied to pleasure, is this aptitude for being endured a great length of time without palling and satiety. The pleasures of sight are of a more lasting kind than those of the inferior senses. From this, and from some other circumstances that I do not here advert to, they enter into the feelings of the Beautiful. Light and shade, and the harmonious arrangement of colours, may suffice to constitute a work of Fine Art. As regards Volition, the pleasures of light so far accord with the general rule ; that is, they stimulate the will in proportion to their degree. We shun gloomy abodes and seek the cheerful day, or the well-lighted room ; when the sunlight is pamfully exces- sive, we I'etire to the shade. There is, however, a remarkable exception to this general rule. In the presence of a light too strong to be agreeable, the eye is worked upon, as by a spell or fascination, and we continue 248 SENSE OF SIGHT. gazing upon what gives pain or discomfort. The experimental proof of the fact is, that we find it a pleasing relief to interpose a screen between us and a light that we cannot divert the eye from, so long as it is within reach. Human beings experience, in a small degree, the fascination that, in the moth, is overpowering, even to self-destruction. This is the first clear indication of the existence of tendencies thwarting the regular course of the will (w^hich is to pleasure, and from pain) ; and constituting us, to that extent, irrational beings. Our sensations appear to have, in some cases at least, an efficacy to attract and detain us, not only while wanting in pleasure, but also when positively painful. (See Contiguity, Ideal Feelings of Movement.) With reference to Intellect, the sensations of sight have a marked superiority in the scale of the senses. The pleasures and pains of sight possess, in the generality of minds, a higher ideal persistence and recoverability than the feelings of any other sense. If there be any exceptions to this rule, they are probably cases of unusual endowment and cultivation of the sense of bearing. The endurability of the sensations without fatigue, and the comparative!}^ easy persistence in memory or idea, may proceed from the same fundamental characteristic — the great delicacy of the shock of light on the nervous substance, as compared with the resulting sensibility. In the most properly intellectual aspect — the bearings upon knowledge, — the superiority of sight is still more pro- nounced. The sensations admit of being discriminated and identified in the highest degree ; and also of being retained in memory as images of surrounding things. The enjoyment of light, like other pleasures, demands alternation, and limitation as to amomit. In sunny climates, the exposure to it for the entire day is excessive and ex- hausting ; it has to be balanced by artificial darkness and shade. Places unable to afford the full quantity that human beings can enjoy, are styled gloomy and dull. 9. Colour introduces a new effect, as compared with COLOUR. 249 white light. By a measured alternation of the different colours we gain a new pleasure, which has all the distinguish- ing peculiarities of the pleasure of light and shade. The decomposition of the solar ray into certain primary colours, in fixed proportions, is so far a key to the harmony of colouring, or to the alternation most agreeable to the mind. We usually speak of the different colours as having characteristic effects : blue and green are reckoned mild or soft ; red is fiery, pungent, or exciting. The eye, when fatigued with the glare of sunshine, is said to find repose in the verdure of the fields. But these allegations cannot be maintained in an absolute sense. Colour, like all other things, operates in accordance with the principle of Kelati- vity. The effect of any single colour is due to the transition from others felt previously. If red were the one universal tint, we should never have recognized colour at all ; we should have spoken only of light and dark. The effects attributed to redness are due to its contrast with the pre- vailing tints about us. Next to white light and shades of dull grey, we are familiarized with blue and green. The balance is usually in favour of the blue end of the spectrum, and, hence, the occurrence of red is a lively stimulation. If the proportions were reversed in nature, — if red and yellow took the place of blue and green, — these last would be the exciting colours : they would have the freshness of rarity and novelty. The pleasure of newly-discovered shades of colour, may be owing to novelty and contrast. The varie- gated aspects of the fields and gardens in the bloom of vegetation, have more beauty than the unbalanced verdure of the leaf. The diffusion of red and yellow supplies the wanting ingredients of the picture. The colours of sunrise and sunset are the scenic splendours of the sky. The strict theory of spectral balance, good as far as it goes, needs to be supplemented by other considerations, in order to render a full account of the characteristic pleasures of colour. 250 SENSE OF SIGHT. Besides the main fact of colour, expressed by 'tint,' there is a distinction in the richness or fulness of the rays conveying the coloured impression : this may vary greatly in the same tint, and the enjoyment will vary accordingly. Another circumstance is the mixture of white light with a colour: this, too, has an efficacy in heightening pleasurable impressions. Among the vast range of distinguishable colour tints, there are some that appear to exercise a peculiar fascination when realized in dress or in decorative effects. The reason of such superiority of charm is not always apparent. How far it is a primitive or intrinsic property is rendered difficult of ascertainment from the existence of adventitious causes of the nature of association, — as, for example, the hues of a fine complexion in the human subject. No doubt, rarity of occurrence may have an influence also. The investigation of such effects, so far as practicable, belongs rather to the higher aesthetic emotions than to the primary sensations of colour. 10. Artificial lights usually fail somewhat in the propor- tions of white light, and, therefore, have the pungency of an unbalanced colour. The flame of a fire is an agreeable stimu- lation ; the intensity does not amount to a painful excess. The light of a lamp arrests and detains the eye ; the fresh sensibility of childhood is delighted with the effect, and soon learns the voluntary movements for following it when shifted about. 11. There remains to be noticed the sensation oi Lustre. The lustrous is opposed to the dull. The pleasure of lustre is greater than the pleasure of colour alone. The most characteristic effect of lustrous bodies is the sparkle, or the occurrence of bright spots in the midst of comparative darkness — a marked case of light and shade. This is a combination highly favourable to the agreeable stimulus of light. Lustrous bodies have a mirror surface, and reflect the sun's rays in beams ; these, starting out at points, are in strong contrast to the remaining surface. The highest beauty of visible objects is obtained by lustre. The metals and precious gems are recommended by it. The \t:sible movements. 251 finer woods yield it by polish and varnish. The painter's colours are naturally dead, and he superadds the transparent film. This property redeems the privation of colour, as in the lustrous black. The green leaf is often adorned by it, through the addition of moisture. Possibly, much of the refreshing influence of greenness in vegetation is due to lustrous greenness. Animal tissues present the effect in a high degree. Ivory, mother of pearl, bone, silk, and wool are of the class of brilliant or glittering substances. The human skin is a combination of richness of colouring with lustre. The hair is beautiful in a great measure from its brilliancy. The eye is perhaps the finest example : the deep black of the choroid, and the colours of the iris, are liquefied by the transparency of the humours. 12. AYe have, next, to deal with the convplex sensations of sight, — those resulting from the combination of optical effect with the feelings of movement arising out of the muscles of the eyeball. As in the case of Touch, this combination is necessary as a basis of those perceptions of the external world that are associated with sight-^Exteruality, Motion, Form, Distance, Size, Solidity, and relative Position. Mere light and colour will not suffice to found these perceptions upon ; as already maintained, in the exposition of Muscularitj' and of Touch, it is necessary to refer them to the moving apparatus of the eye and of the body generally. 13. Visible Movements. — One of the earliest acquired of our --y voluntary actions is the pot\-er of following a moving object by the sight. Supposing our gaze arrested by a strong light, as a candle-flame, the shifting of the candle would draw the eyes after it, partly through their own movement, and partly by the rotation of the head. The consequence is a complex sensation of light and movement, — just as the sensation of a weight depressing the hand is a sensation of touch and movement. If the flame moves to the right, the right muscles are engaged in following it ; if to the left, the left muscles, and so on. Thus we have several distinct com- binations of light and muscular impression, marking dis- 252 SENSE OF SIGHT. tinctness of direction, and never confounded with one another. Motion, instead of continuing in one direction, may change its direction, and take a course crooked or curved. This brings into play new muscles and combinations, and leaves behind a different record of muscular action. The right muscles of the eye may have to act along with the superior muscles, and at a shifting rate. This gives an oblique and slanting direction, which we can ever afterwards identify when the same muscles are similarly brought into operation. We have thus a perfect discrimination of varijing directions, through the distinct muscles that they bring into play. We can, with the eye, as with other active organs, dis- criminate the greater or less continuance of a movement, and can thereby estimate Duration in the first instance, and, in the next place, obtain another instrument applicable eventually to estimating Extended Magnitude. Our muscular sensibility also discriminates rate or velocity of movement. A quick movement excites a different feeling from one that is slow ; and we thence acquire graduated sensations, corresponding to degrees of speed, up to a certain limit of nicety. This'estimate of the rate of contraction also indirectly serves as a means of judging of Extension, after we have arrived at the notion of visible Space, as opposed to Succession in Time. The muscular sensibility of the dead strain, or of Resist- ance, can scarcely occur in the eye ; there being nothing to resist its movements but its own inertia. Wliat is called straining the eye (which happens in close and minute vision) is not the same thing as straining the arms in the support of a heavy w^eight. Hence, of the three primary sensibilities of muscle — Resistance, Continuance, and Speed, — two only be- long to the ocular muscles. Accordingly, the eye, with all its superiority in giving the mind the pictorial array of the extended world, cannot be said to include the fundamental consciousness of the object universe — the sense of Resistance. SPECTACLE OF MOVING OBJECTS. 253 There is a certain kindred sensibility in the common fact of muscular tension ; but it is by association, and not by intrinsic susceptibility, that the power of vision impresses us so strongly with the feeling of the Object world. While the retina of the eye is receiving one and the same optical impression (in the supposed case of the candle-flame), this may, by movement, be embedded in a great many different muscular impressions, and may thus go to constitute a great variety of pictorial effects. By changing the muscles and by varying their rate of action, we may so change the resulting impressions, that any one motion shall be recognized by us as distinct from every other, while each may be identified on a recurrence. Many of the pleasures of Muscular Movement, described in the previous chapter, may be experienced in the spectacle of moving objects. The massive languid feeling of slow movement, the excitement of a rapid pace, the still higher pleasure of a waxing or waning speed, can all be realized through the muscles of the eye and the head. The slow procession, the gallop of a race-horse, the flight of a cannon- ball, exhibit different varieties of the excitement of motion. In the motion of a projectile, where a rapid horizontal sweep is accompanied with a gentle rise and fall, we have one set of muscles quickly moved, and another set in slow varying tension, thereby contributing the still more agreeable effect of increasing and dying motion. While the projectile flies across the field of view, the horizontal motion is uniform, but the pace upwards diminishes, and at last dies away . at the highest point. The body then recommences a downward course, slow at first, but accelerating until it reach the ground. Hence the beauty of curves. The pleasures of moving objects and stirring spectacle count for much in the excitement of human life. They are really pleasures of action ; but, inasmuch as only a very limited portion of muscle is excited by them, they do not constitute bodily exercise, and are, therefore, to all practical intents, passive pleasures, like music or sunshine. Whence 254 SENSE OF SIGHT. dramatic display, the ballet, the circus, the horse race, games and sports, although engaging the activity of the eye, do not belong properly to our active enjoj^ments. They may, how- ever, be the means of stimulating the general activity of the frame. Among the 'permanent imagery of the intellect, recalled, combined, and dwelt upon in many ways, we are to include visible movements. The flight of a bird is a characteristic that distinguishes one species from another; and the impres- sion left by it is part of our knowledge or recollection of each individual kind. The gallop of a horse is a series of moving pictures, which leave a trace behind them, and are revived as such. The motions that constitute the carriage and expression of an animal, or a man, demand particular movements of the eye, in order to take them in and store them up among our permanent notions. All the gestures, modes of action, and changes of feature that emotion inspires, are visible to the eye as an assemblage of movements ; and we recognize such movements as marking agreement or difference among individuals, and between various passions. Many of the aspects of the external world impress them- selves upon the moving apparatus of the eye. The surface of the sea, the drifting of clouds, the fall of rain, the waving of trees in the wind, the rushing of water, the darting of meteors, the rising and setting of the sun — are all mixed impressions of spectacle and movement. In like manner, in the various processes of the arts, there are characteristic movements that constitute our means of discrimination, and our permanent notions of those processes. The evolutions of an army have to be remembered as movements, and, there- fore, need to be embodied among the muscular recollections of the system. 14. Visible Form. — We have taken the case of moving objects as the least complicated experience of vision. We must, now, inquire by what process we perceive Visible Form and Extension, and acquire the notion of Simultane- ous existence in Space. It has to be shown that the eye is SUCCESSION AND CO-EXISTENCE. 255 active in the observation even of still life ; the special mode of activity being such as to make the mind feel the difference between Succession and Co-existence. When we follow a moving object, as a rocket, or a bird, and when we carry the eye along the curve of the rainbow, there is a common fact of movement, with important dif- ferences in the mode. These differences are, to a great degree, parallel to those described under Touch, whereby the knowledge of objects as co-existing is attained. (1) In the first place, in following the outline of the rainbow, we are not constrained to any one pace of movement, as with a bird or a projectile. This alone would give a lively sense of difference between the two appearances. (2) In the next place, the optical impression, in the case of a still form, is not one unchanging sensation, but a series of sensations, which may be of the same nature (as in the rainbow), or may be all different— as in sweeping across the clouds or the landscape. (3) Thirdly, we can, bj^ an inverted movement, encomiter the same series of optical sensations, in the inverted order ; whereas, in the other case, the object passes finally away from the sight. (4) In the fourth place, we may repeat the movement, at any rate of speed, and in so doing obtain the same series of sensations, in the same order. Both in touch and in sight, this result is pro- bably what, more than anything else, gives us that vivid sense of the difference between objects moving and passing away — thereby typifying Succession — and objects that are simultaneous or co-exist, which is the meaning of Space. The more frequently we experience such fixed recurrence of optical sensations, in company with a definite movement, the broader is the line between that form of being and the objects that give us only one chance of observing them. The constant reception of a definite series of sensations by one definite movement, and the equally constant occurrence of the series inverted under an inverted movement, go far to make up our notion, meaning, and expectation, of objects extended in Visible Space. 256 SENSE OF SIGHT. But, (5) in the fifth place, as regards Sight, the pecuhar power of the eye to embrace at one glance a wide prospect, although minutely perceiving only a small portion, is avail- able to confirm the same distinction. When the glance is carried along the field of view, the portions that cease to occupy the centre of the eye still impress the retina, and have a place in the consciousness, though much less dis- tinctly perceived. This constitutes a vital distinction between the transitory flight of a meteor and the picture of the starry sphere. Touch possesses this means of discrimina- tion only in a very limited degree. The extended surface of the hand, the plurality of fingers, the united touch of the two hands, and such extent of the surface of the body as can make a simultaneous contact, — are all that there is to correspond to this great prerogative of sight, in giving a plurality of simultaneous impressions, so as to markthe difference between the co-existing in -Space and the successive in Time. When a definite series of successive sensations are simultaneouslij felt, they suggest all the separate facts of movement, together with the whole fact of movement, involved in a perception of the Extended. Thus, then, the observation of the foi-ms of still life is a combination of the movements of the eye, with the optical impressions corresponding to the different parts of the field of view. Exactly as in the case of moving things — by a horizontal sweep, we take in a horizontal line ; by a circular sweep, we derive the muscular impression of a circle ; by a sudden change of direction, we are cognizant of an angle ; there being, in all these instances, the persistence on the retina of the whole figure, while the eye scans the successive parts. The transition is easy from Lines to Surfaces. A more numerous and complex series of movements is requisite to give the impression of a visible area or superficies. But the same constant series of optical effects, embedded in the same movements, inverted and repeated as often as we please, enters into the cognition of space in two dimensions, as well I APPARENT SIZE. 257 as into the perception of linear magnitude, or space viewed in one dimension. 15. Apparent Size. — The apparent size or visible magni- tude is made up of the two discriminations — optical and muscular. The Optical discrimination takes place through the extent of the image on the retina ; hence, the apparent size is spoken of by Wheatstone as the retinal magnitude. The Muscular discrimination depends upon the sweep of the eye under the action of its muscles ; and is, therefore, a fact or experience of our muscular energy or activity. The two estimates co-operate to a joint result. They are both equiva- lent to an angular estimate, or the proportion of the visible surface to a whole sphere. The apparent diameter of the sun or moon is half a degree, or -|o of the circle of the sky. The combined estimate of Ketinal Magnitude, by our two most sensitive organs — the retina and the ocular group of muscles, — renders our measurement of apparent size singu- larly delicate. In fact, this is the finest discrimination within the compass of our senses ; and, whenever we desire to measure any property with nicety, we endeavour to resolve the case into a comparison of visible magnitudes. Of this description are the standards of weight (the balance), of heat (the thermometer), and many others. The fluctuations of visible magnitude in consequence of changes of Distance are appreciated with similar delicacy ; and, after we are aware that these fluctuations correspond to alteration of real distance, we use them as the most delicate test of remoteness. The celestial bodies and the clouds are conceived by us under their apparent or visible size solely. Terrestrial objects, being seen by us at different distances, vary in apparent size, and we conceive most of them under a inore or less perfect estimate of their real size, as ascertained by handling and locomotion. Failing this estimate, we adopt some one point of view, which we have been most accustomed to, and conceive the object as seen from thence. 17 258 SENSE OF SIGHT, In regard to very familiar things, as a chair, or a man, we uniformly translate the apparent estimate into a real estimate. A building, a distant mountain, a landscape, are visually conceived as they appear from our most usual position with reference to them. 16. Distance, or Varying Remoteness. — The apparent size, as above considered, includes only two dimensions. In order to appreciate apparent volume or solidity, as an advance upon mere extension, or surface, we must estimate varying remoteness also. Leaving out, at the present stage, the consideration of real distance, as well as real magnitude, we ina.y adv^ert to the various ocular sensibilities affected by alteration of distance. We have already remarked on the two muscular adapta- tions of the eye to distance, — the change in the eyeball by the operation of the ciliary muscle for near distances, and the convergence or divergence of the two eyes for distances both near and far. To preserve a distinct image when an object is brought nearer, we need, by a muscular effort, to change the curvature of the crystalline lens in each eye, and to make the lines of sight of the two eyes converge. Both these efforts are attended with consciousness, and this con- sciousness mingles with the feelings of altered retinal mag- nitude, and with dissimilarity of binocular images, when objects retreat from the eye or advance toward it ; while, in addition, the optical fact of varjdng clearness may also tell, together with the presence or absence of intervening objects. 17. Visible Movements and Visible Forms in Three Dimen- sions : Volume. — By combining the visible movements across the field of view with the movements of adjustment — mon- ocular and binocular, — we attain the experience of visible movements, visible forms, and visible magnitudes, in all the three dimensions of space ; in other words, volume and solidity, in so far as these are understood by the eye alone. An object moving aslant requires changes of adjustment INTELLECTUAL COMPASS OF THE EYE. 259 along with the movements of the eyeball, right or left, up or down ; and its image remains embodied in this more compli- cated series of movements and optical changes. A row of houses seen obliquely needs the same combination. With the lateral movements of the eye, we must unite adjusting movements, in order to maintain the same distinctness of picture throughout. These changes of adjustment are re- peated and inverted, along with the other movements, and conspire with these to give the sense of the co-existing in space, as opposed to the passing or successive in time. 18. The intellectual imagery derived through the eye from the forms of still life is co-extensive with the visible universe. For the purposes of discriminating and of identifying natural things, and also for the storing of the mind with knowledge and thought, the sensations of objects of sight are available beyond any other class. The eye is kept constantly at work upon the surrounding scene, follow- ing the outlines and windings of form, as these extend in every direction ; and, by the movements thus stimulated, each separate object is distinguished from those that diifer, in shape, size, or distance, and identified with itself and those that coincide with it in these peculiarities. The train of movements for a square are recognized as distinct from the train that describes an oval : the outline of a pillar brings on a cycle of motions wholly different from those dictated by the figure of a tree. The power we possess of giving mental coherence to movements that have been described in succession, fixes the series for each different view, and gives a permanent hold of all the distinct forms presented to the eye. This adhesive process belongs to the intellect, and will be fully treated of in the proper place. CHAPTEE III. THE APPETITES. 1. IT^HEN the Sensations are exhaustive!}' described, ' * inchiding not merely the Five Senses, but the Muscular and Organic Feelings, there is nothing left for the special heading of Appetite except to mark and sum- marize a select class whose importance grows out of their bearing on our subsistence. The appetites have been de- fined as the cravings produced by the recurring wants and necessities of our bodily or organic life. In detail, they are enumerated as Sleep, Exercise, Bepose, Thirst, Hunger, Sex. Appetite refers more particularly to the active side of these sensibilities, — that is to say, their influence on the AVill. Certain wants of the system lead to a condition of pain, with the natural urgency to work for its abatement or removal. The conscious relief from pain is followed by an accession of positive pleasure, which provides an additional motive, so long as the increase continues. The measure of the voluntary prompting is the measure of the painful and pleasurable feelings involved in the case. 2. The fact of periodic recurrence is in no case more strik- ingly exemplified than in Sleep. After a certain period of waking activity, there supervenes a powerful sensation of re- pose. If we give way to it at once, the state of sleep creeps over ns, and we pass through a few moments of agreeable repose into unconsciousness. If we are prevented from 3'ielding to the sleepy orgasm, its character as an appetite is brought out into strong relief. The voluminous uneasiness that possesses all the muscles and organs of sense, stimulates a strong resistance to the power that keeps us awake ; the uneasiness and the resistance increasing with the continued SLEEP. — EXEECISE AND REPOSE. 261 refusal of the permission to sleep, until the condition becomes intolerable, or until a reaction ensues, which drives off the drowsiness for a time. The ovei-powering influence of drowsiness is well seen in infants. 3. The necessit}' of alternating Exercise with Repose, through the entire range of our active organs, brings on the like periodic cravings and deep-seated uneasiness. The fresh condition of the muscles is of itself a sufticient stimulus to action : without any conscious end, — in other words, without our willing it, — action commences when the bod}' is refreshed and invigorated. If this spontaneous outburst is checked, an intense uneasiness is felt, being one of the conscious states incident to the muscular system. This state is of the same nature as all the other appetites, and increases with privation, unless, by some organic change, the fit passes over for the time. The dog chained up to his couch, the child restrained from bursting out in its exuberance — experience all the pains and desire of the active organs for exercise. On the other hand, after exercise, comes an equally powerful craving and impulse to rest, which, if resisted, produces the same intense uneasiness. Under this head of Exercise and Kepose, I might include the more active of our senses, — that is, Touch, Hearing and Sight. These senses all embody muscular activitj^ along with the sensation peculiar to each ; and the muscular activity, together with the tactile, auditory, and visual sen- sations, leads to weariness of the parts, with a craving for rest ; while these, after due repose, resume the fresh condition and crave for the renewal of their excitement. The alternate exercise and rest of the senses is in a great measure involved in the rotation of sleeping and waking ; indeed, the invo- luntary torpor of the nervous system is almost the only means of giving repose to senses so constantly solicited as sight, touch, and hearing. A similar train of remarks might be extended to the activity of the Thinking organs. But, in these, the periodic cravings are less distinctly marked, and more frequently 262 THE APPETITES. erroneous, than in the case of muscular exercise. There is often a rehictance to engage in thought, when the brain is perfectly vigorous and able to sustain it ; and, on the other hand, there is, in nervous temperaments, a tendency to ex- cess of mental action, uncorrected by any regular prompt- ings to take repose. The feeling of fatigue, arising soon after beginning a laborious operation, and then disappearing, is connected with inaction of the brain. A little time is requisite to determine the flow of blood to the parts exerted. 4. Thirst and Hunger I have already touched upon. ' Wliat is called thirst is sometimes rather a call for the cooling influence of cold drinks, as for instance, in the dry, hot state of the air-passages, mouth and skin, produced in fevers by the increased temperature and diminished tur- gescence of the parts. Exhalation is, in such cases, often rather diminished, and the dryness of the surface arises from the circumstance that, although blood still flows through the capillary vessels, the reciprocal action between the blood and the living tissues, which is denominated turgescence, or tm-gor vitalis, is depressed ' (Milller, by Baly, p. 530). Hunger, unlike Thirst, is due to a state of the stomach, as yet not exactly understood ; while the feeling of inani- tion, which also grows out of long fasting, must be con- sidered as a general feeling of the system. The urgenc}^ of hunger ought to be in accordance with the actual deficiency of nutritive material ; but, very frequently, the case is other- wise. ' It is heightened by cold baths, by friction of the skin, by friction of the abdomen, and by the agitation to which the abdomen is subjected in horse exercise, as well as by muscular exertion.' It is diminished by all nauseating influences, which, probably, at the same time weaken the digestion. ' The local sensations of hunger,' says Miiller, ' which are limited to the digestive organs, and appear to have their seat in the nervus vagus, are feelings of pressure, of motion, contraction, qualmishness, with borborygmi (grip- ings), and finally pain.' HUNGER — SEX. 263 In the case of Hunger, as in most of the appetites, there is a double spur to the taking of food : first, the stimuhis of uneasiness, and, next, the impulse arising out of the pleasure of eating. It is well understood that these two things are quite different ; and on their difference hangs the whole art of refined cookery. Very plain food would satisfy the craving for nutrition ; but there is a superadded pleasure in eating, which we have to cater for. The one is the appetite in its strictest signification, and, presumably, as found in the lower animals ; the other we may call a desire, because it supposes the remembrance and anticipation of a positive pleasure. It is in the process of taking food and drink that we best see exemplified the activity springing out of the sensa- tions of hunger and thirst. The actual assuaging of the uneasiness produces an intense pleasurable sensation that sets on the most vigorous movements for being continued and increased ; while the moving organs themselves, begin- ning to be invigorated, display a spontaneous and lively energy in the cause. To bring together, and make to unite, the sensation of the appeasing of hunger with the acts of sucking, prehension, masticating, and swallowing, is perhaps the earliest link of volition established in the animal system. This is the first case of action for an end, or under the prompting and guidance of a feeling, -that the newly-born infant is capable of. Besides the natural craving for the elements of nutrition required by the tissues, we may acquire artificial cravings by the habitual use of certain forms of food, and certain accoin- paniments, as peppers, flavours, etc. Thus, we have the alcoholic craving, the craving for animal food, for tea, coffee, tobacco, etc. 5. The Appetite that brings the Sexes together is founded on peculiar secretions which periodically accumulate within the system, producing a feeling of oppression until they are either discharged or absorbed ; there being a certain intense pleasure in discharging them for the ends of reproduction. If we were to ])lace these feelings among Sensations, they 264 THE APPETITES. would either form a class apart, or they would fall under the first class already described, — namely, the Sensations of Organic Life. If the subject were open to full discussion, like the other feelings of human nature, it inight be best to treat them as an organic sensibility gi^'ing birth to a special Emo- tion. We have in this case, as in hunger, both appetite and desire ; but we have also, what does not occur to a like degree in hunger, a many-sided susceptibility to inflamma- tion, — through all the senses, through the trains of thought, and through various emotions. 6. The accustomed Eoutine of life leads to a craving almost of the nature of Appetite. As the time comes round for each stated occupation, there is a tendency or bent to proceed with that occupation, and an uneasiness at being restrained. So, our appetites, properly so called, may have their times of recurrence determined by our customary periods of gratifying them. 7. All the appetites are liable to be diseased or perveiiied and to give false indications as to what the system needs. They are likewise liable to artificial and unseasonable inflam- mation, through the presence of the things that stimulate and gratify them. In the lower animals, it is assumed, I know not with what truth, that appetite rarely errs ; in humanity, error is extremely common. We are apt to crave for warmth when coolness would be more wholesome ; we crave for food and drink, far beyond the limits of sufficiency ; we indulge in the excitement of action when we ought to cultivate rest, or luxuriate in repose to the point of debility. So doubtful is the appetite for sleep, that there is still a dispute as to how much the system requires. Perhaps, the complicacy and the conflicting impulses of the human fraiue, are the cause of all this uncertainty and mistake ; rendering it necessary for us to resort to experience and science, and to a higher volition than appetite, for the guidance of our daily life. CHAP TEE IV. THE INSTINCTS. 1. TN the foregoing chapters, have beeu enumerated all the X primary modes of consciousness. We have now to consider in full the original provision in the human system, for Action. The name 'Instinct' is especially reserved for what is primitive or primordial on the active side. More expressly, Instinct is defined as the untaught ability to perform actions of all kinds, and especially such as are necessary or useful to the animal. In it, a living being possesses, at the moment of birth, powers of acting of the same nature as those subsequently conferred by experience and education. When a newly dropped calf stands up, walks, and sucks the udder of the cow, we call the actions instinctive. 2. In all the three regions of mind, — -Feeling, Volition, and Intellect, — there are certain primitive and fundamental arrangements, which education or acquisition proceeds upon. A full account of all our instinctive endowments may be included under the following heads : — I. The Beflex Actions. — These are actions withdrawn from the sphere of mind, and yet having analogies, as well as contrasts, with proper mental actions. II. The primitive arrangements for conihuted a)id liarnio- nious actions. — The rhythmical acts of walking, flying, swinj- ming, etc., are examples of these. The Will may supply the stimulus to move, but the harmonious grouping of the movements is, in many instances, provided for among the natural endowments of the system. III. The connexions existing at the outset between Feelinq and its bodily manifestations. 266 THE EEFLEX ACTIONS. IV. The instinctive orerm of Volition.- — What we call the power of the will, has to be traced back, if possible, to some inborn or primitive stimulus, connecting together our feelings and our actions, and enabling the one to control the other. This is perhaps the most delicate inquiry that our science presents. The primitive foundations of Intellect will be alluded to,, but cannot receive full justice until a later stage. THE REFLEX ACTIONS. 3. The Eeflex, Automatic, or Involuntary actions, are marked l)y the absence of the circumstance characterizing voluntary [ actions, — namely, the stimulus and guidance oi feeling. Many of them are essential to animal life. They all demand a nervous arrangement, consisting of incarrying and outcarrying fibres, connected by grey matter. Some depend on the spinal cord either dhectly or through the sympathetic nerves and ganglia ; a second group are related to the medulla oblongata ; and some are actuated by still higher centres, as the pons varolii and the corpora quad- rigemina. Occasionally, the sympathetic ganglia and a portion of the cerebro-spinal masses concur to the responsive movement ; but the ganglia are merely nutritive or distributive in function. The Eeflex Actions may be distributed as follows : — First, those concerned in the organic processes, and operated through the involuntary muscles, — being the most widely removed of all from the mental or voluntary sphere. The rhythm of the heart cannot any longer be counted among reflex actions properly so called. The heart is capable of rhythmic action in entire dissociation from the nervous system — central or local. The heart-muscle itself — there are many grounds for so concluding — seems to retain the primitive irritability (or spon- taneity) of 'undifferentiated protoplasm'. The embryonic heart beats I'hythmically before there is any nervous connexion at all ; and, thoutrh it ultimately becomes subject to the control of the local and central nervous mechanisms, its action pereists, not as a reflex action, but rather as a definite spontaneity. In the fully developed organism, however, the heart is subject to cerebro- spinal control hx two main connexions — first, the vagus nerve, VASO-MOTOR ACTION. 267 second, the sympathetic nerve ; both connecting the cerebro- spinal centres with the cardiac gangha (the local mechanism). Stimulation of the Vagus (or inhibitory nerve) results in arrest of the heart-beats. When these begin again, they are at first feeble, but, in the end, become more vigorous than before the arrest. This indicates that inhibition is the concomitant of a restorative or anabolic process in the muscle. On the other hand, stimu- lation of the Sympathetic (or augmentor nerve) results in a quickening and strengthening of the heart-beats. Ultimately, however, they become more feeble. This indicates that the augmentation is a destructive or catabolic process. In both cases — inhibition and augmentation — reflex action may play a part ; since both the vagus and the sympathetic may be brought into action by stimuli from the skin, from internal viscera, from other parts of the nervous system — the parts, for example, con- cerned in the emotions. To this extent, the heart-rhythm falls among reflex actions. Connected with the circulation of the blood, there is, also, what is called, the vaso-motor action ; w'hereby the smaller arteries, which possess muscular fibres, are contracted or expanded, so as greatly to modify the local circulation. The contraction of these fibres, due to the influence of the central nervous system acting through the sympathetic nerves, diminishes the bore of the vessels, and lessens the flow of blood to the parts; their relaxation widens the bore, and gives an increased flow, with rise of temperature and quickened action upon the nutrition of the locality. The per- manent contraction, maintained in these fibres through the sympathetic nerves, is not a pure case of reflex stimulation. Through the vaso-motor agency, the secretions and excretions are greatly affected by nervous influence ; it being uncertain whether this is the sole instrumentality whereby the processes of organic life are subjected to the nervous centres. In all proba- bility the secretory organs are directly affected by nerves independently of the vaso-motors. More clearly reflex are the movements of the intestinea. The whole of the intestinal canal is provided with nmscular fibres, circular and longitudinal, of the unstriated or involuntary species. By the successive contraction of the circular fibres, aided by the longitudinal, the food is propelled along the entire course of the 268 THE KEFLEX ACTIONS. tube, through reflex stimulation. The first stage of the process commences with Deghitition, or swallowing, which succeeds to mastication. Of the three steps of deglutition, one is purely voluntary, being the propulsion of the food, by the concurrence of the lower jaw, mouth, and tongue, into the bag of the throat, called the pharynx ; from which point the movements are purely reflex and involuntary. In the second stage, the contact of the food with the walls of the pharynx brings on the rapid contraction of the constrictor muscles of the pharynx, together with the auxiliary operation of the muscular fibres for raising the palate, and those (called stulo-phariingpi) for drawing the walls of the pharynx upwards. The third stage of deglutition occurs in the oesophagus, or gullet, w^hose circular fibres successively con- tract in a wave-like manner from above, downwards ; while the longitudinal fibres, drawing up and w'idening the tube, facilitate the descent. This peculiar action, called vermicular or peristaltic action, is extended through the whole length of the alimentary canal. Both the cerebro-spinal and the sympathetic systems are concerned in maintaining the action. The stimulus is the con- tact of the food and of the various digestive fluids, of which fluids the most efficient is the bile. This instance exemplifies reflex action in its simplest and most widely spread form, — namely, contact with a surface responded to by the muscles of the locality. At each point, the food stimulates the circular and longitudinal fibres of the part touched and those immediately in the rear, so that the morsel is gradually propelled in the forward direction. In the pharynx, the action is violent and rapid (being under the powerful control of the medulla oblongata). As respiration is intermitted during the act, no time must be lost ; while certain adjoining muscles concur with the muscles of the pharynx. In the intestine, the action is compara- tively feeble and slow : the time of descent of the food along the small intestine is estimated at about three hours. Such is the regular course of reflex action in the alimentary canal. Among occasional and extraordinary stimulations, we may include the production of diarrhoea and colic by irritating substances— which is the same process in a more violent form. A strong irritation will operate at a distance from the part affected, as when these derangements of tlie bowels are brought on, in MOVEMENTS OF THE INTESTINES.- 269 infants, from teething. This shows the influence propagated along the main chain of the sympathetic, instead of being re- flected from a single point ; it being the tendency of all powerful stimulation to extend its influence. The same tendency is shown in the other direction, w'hen irritation of the alimentary canal produces, in infants, squinting and convulsions, and, in adults, epilepsy. Among reflex acts, connected with digestion, we have to include vomiting. The most usual stimulus is the presence of indigestible, irritating, or poisonous substances in the stomach. The response necessary to vomiting is somewhat complicated. The act is proved to occur in two w'ays. One is by an anti-peri- staltic movement of the intestine, or by an inversion of the order of contraction of the muscular fibres. It is conceivable that violence of irritation may have this effect, not by any specific nervous connexion, but by mere derangement of the usual rhythm. Colic and diarrhcea would be varieties of the same deranging stimulus. In the other mode, which is the one most frequently observed, the effect arises through the abdominal muscles. This wall be adverted to under the next head. In the Second class of reflex actions, organic processes are affected, but the instrumentality is the voluntary muscles. The chief example is respiration, depending chiefly on the medulla oblongata. The great muscle of respiration is the Diaphragm, whose contraction performs the heaviest duty, namely, inspiration or drawing in breath ; while the natural rebound or elasticity of the chest is the chief cause of expiration. Other muscles aid the diaphragm in the inspiratory act ; and certain muscles, as those of the abdomen, the internal intercostals, the infracostals, and the muscles of the back, may co-operate with the elasticity of the chest and lungs in expiration. The action consists of a simple rhythm, or alternate contrac- tion and relaxation of the diaphragm, as the muscle in chief ; while the co-operating muscles, so far as brought into play, receive, in like manner, an alternated stimulation. Although respiration is adduced as a perfect example of the reflex process, there is some doubt as to the exact stimulant employed. The connnencing of respiration at birth is said to be 270 THE REFLEX ACTIONS. due to the effect of cold — especially in the skiu of the face — transmitted to the medulla oblongata by the nerves of the fifth pair. We must suppose, however, what everything confirms, that this nervous centre is itself a very energetic one, waiting only for the slightest touch to discharge itself with the requisite vigour. All through life, cold, especially on the face, stimulates respiration ; even so small an application as the fan, in a heated room, rallies the weakened action of the lungs. When respiration is once established, the stimulus is supposed to emanate from the surface of the lungs, and to be due to the influence of the venous blood, surcharged wath carbonic acid and other impurities, and devoid of oxygen; but, in the absence either of decided facts, or of the analogy of a principle, this must be looked on as conjecture. Granting that there is reflex stimulation properly so called, we may assume that there is a considerable spontaneous emanation, modified but not created, by stimulants.* The principal circle of nervous action is by the vagus nerve (sensitive or incarryiug), a small part of the back of the medulla oblongata; the nerves supplying the miiscles of respiration, and the phrenic (motor). The circle is extended by including the fifth pair (sensibility of the face) ; and by the spinal nerves (tactile and motor) all over the body. As before remarked, there is little complication in the process : the great desideratum is energy of * Wheu the sensory nerve distributed to the surface of the lungs is cut through, the breathing action is weakened, showing that a certain amount of stimulus is derived from the action going on throughout the surface. If, further, the brain is paralyzed by any poison, the respiration is still more enfeebled, leading us to infer that the brain contributes to the breathing activity. Dr. Brown- Sequard has been led, by the examination of a great many cases, to the conclusion that the whole base of the brain is employed in respiration. He says : ' All the facts just mentioned, and many others, have led me, first, to abandon the view so generally admitted, that the medialla oblongata is the essential source of the respiratory movements in the nervous centres ; and, secondly, to propose the view that these movements depend upon the incito-motorij parts of the cerebro-spinal axis, and on the grey matter which connects those parts with the motor nerves going to respiratory muscles '. The chief stimulus to respiration is the action on the surface of the lungs, but ' excitations fi-oni all parts of the body (as by cold, for mstance), and also direct irritations of the base of the brain and of the spinal cord, almost constantly taking place, contribute to the production of respiratory movements ' {Lectures, p. 192). RESPIRATION. 271 impulse, following a very simple rhythm. In so far as the operation can be kept up by the diaphragm alone, it is the simplest of all arrangements ; a mere exertion and remission of one definite stimulus. The accessory muscles are two opposed groups, like the flexors and extensors of the body ; and, that such muscles should be stimulated by turns, is a consequence of their being stimulated at all. By the great la^Y of conservation, to be noticed presently, a process so essentially hnked with the vital energies of the system would extend the compass of the actions ministering to it, bringing into play remote accessories, as well as augmenting the power of the principal instrument, the diaphragm. The breathing apparatus is the medium of certain acts, of occasional occurrence, more decidedly of the reflex character than the breathing function itself. One noted example is cough- inn. Although this act is accompanied with a painful sensation , giving birth to a voluntary impulse, which counts as part of the case, yet there is a marked concurrence of reflex, in the sense of involuntary, stimulation. The localities whose irritation makes us cough are — -the glottis, the larynx with the air tubes of the lungs, and the throat or fauces. The irritants are diseased secre- tions from the lungs, and from the stomach, passing over those parts ; also, solid and liquid substances entering from without — as when food or drink enters the larynx ; irritating gases ; and, lastly, cold air. The first and immediate result of the reflex stimulus is, by the contraction of the arytenoid muscle, to close the glottis, together with the upper opening of the larynx. The second act is a violent movement of expiration, such as to force open the glottis, and clear the passages of the irritating sub- stances ; the instrumentality being the abdominal and other muscles auxiliary to expiration. The more purely reflex operation is probably seen in the first act, which follows the most general law of reflex stimulation — the contracting of the muscles of the locality affected. In the second act, the influence takes a wider sweep ; and, through the medulla oblongata, finds its way, by the respiratory nerves, to the muscles of augmented expiration. The irritation produces that peculiarly unendurable feeling called tickling, which, though not of the ordinary character of acute pain, always prompts to energetic voluntary movements for getting rid of it. The ex- 272 THE KEFLEX ACTIONS. planation probably is, that we are made very uncomfortable by the reflex stimulation engendered through a slight touch of very sensitive parts. This second act, if not entirely voluntary, is so in part, and is prompted, in the last resort, by the self-conserving tendency, which is the only known source of volition. Coughing may arise from cold air on the skin, from coldness of the feet, and from general chillness. In most of these in- stances, if not in all, there is an intermediate effect of the rise of phlegm from the lungs or the stomach — the consequence of the disturbing agency of the cold ; so that the irritation of the glottis or neighbouring parts is still the direct influence. Sneezing closely resembles coughing, and the two illustrate each other. The surface afl'ected is the interior of the nose. The irritants are pungent gases, and foreign substances lodging in the cavities of the nostrils. The immediate response, parallel to the closing of the glottis in coughing, would appear to be the closing of the fauces, so as to divert the breath from the mouth to the nose. The more conspicuous act consists in a deep and sudden inspiration, followed by a clearing explosion through the nostrils by a grand expiratory effort. Some part of the stimulus must be regarded as voluntary, with a view to deliverance from the tickling sensation ; for, although a sleeper may be made to sneeze by ad- ministering snuff" or other pungent substance, the consciousness is awakened preparatory to the act. When too much light, or the rays of a fire, on the face or head, make one sneeze, there is probably first a reflex effect, of the vasi-motor kind, producing a floW' of mucus in the nose. Suckiwi is a reflex act, passing into the voluntary. The pre- paratory step is the closing of the lips round the nipple — a purely reflex process, stimulated by a mere contact. There are certain concurring adjustments. The tongue is brought forward to the nipple. In the throat, by means of the palate, uvula, and posterior pillars of the fauces, the entrance of air to the mouth through the nose and pharynx is prevented, while respiration is still possible (by the nose), except at the instant of swallowing. The act, then, consists in drawing away the tongue (the air-tight contact of the lips remaining), so as to produce a partial vacuum in the mouth, and a consequent in-flow of milk by atmospheric pi-essure. The mere withdrawing of the tongue, however, does VOMITING. 273 not of itself suffice ; this might be done, as any one can test, without swehing out the closed cavity of the mouth. Either there must be a bulging action of the cheeks, through the buccal muscles, or a momentary inspiration, with the nostrils closed, which would bring about the needful disturbance of the atmo- spheric equilibrium. ^Ye have already alluded to the act of vomiting, as per- formed through the involuntary fibres of the alimentary canal. More usually and obviously, it takes place through the abdominal muscles. When the pyloric muscular ring (at the outlet of the stomach into the duodenuin) contracts tightly, while the cardiac orifice (the enti'ance to the stomach) is open, the abdominal muscles, operating powerfully, expel the contents of the stomach from the mouth. The action is essentially an irregular one ; the due concurrence of all the acts not being provided for by a pre- conceived arrangement. Sometimes the cardiac fibres are con- tracted, as well as the pyloric, through the reflex stimulation of the alimentary canal itself; in that case, the attempts at vomiting are ineffectual. In order to procure the aid of the abdominal muscles, the medulla oblongata must be affected. Hence, there is required a sufficiently powerful stimulation of the pneumo-gastric nerves. This may be gained by an irritating contact with the surface of the stomach — the most usual cause of vomiting. The effect may also arise by tickling the fauces ; whence must proceed a very powerful stimulation to the medulla oblongata at the point where the nerves issue to the abdominal muscles. Certain tastes are called nauseous, from their tendency to excite the stomach to vomiting ; the nervous agency in this case being the glosso- pharyngeal nerves, also connected with the medulla oblongata. Nauseous odours probably operate through the same nerves : the olfactory track would carry the influence too far about. Certain sensations, in their origin still more remote from the stomach, bring on sickness ; as a severe prostrating blow on the shin, the testicle, or the eyeball. The seat of irritation, in this case, is the brain, in the first instance ; from which an influence is diffused to the medulla oblongata. The same may be said of violent emotion generally, — which may lead to sickness. Concussion of the brain is also a cause. These circumstances would indicate the 18 '274 THE REFLEX ACTIONS. result as due to a great loss of cerebral power, and the dis- turbance of some tonic state or balance, permitting a special and local outflow of stimulus, which the healthy condition holds in restraint. The case of sea-sickness would readily accord with the same view. The aid given to defaecation by the abdominal and expiratory muscles is probably altogether voluntary. Infants seem incap- able of the effort ; in them, accordingly, the reflex peristaltic move- ments of the intestines are the expelling instrumentality. The expulsion of the male semen is a reflex act operated through the sensory nerves and the cerebro-spinal centres ; the muscles are of the voluntary species. In a Third class of reflex actions, the organic functions are affected through the medium of the cerebro-spinal system. Salivation is controlled by the nerve of taste. A sapid body entering the mouth causes an increased flow of saliva. The sali- vary glands are all connected with the sympathetic system of nerves ; the small arteries of the blood-vessels being kept at a certain point of contraction through the vaso-motor influence of the sympathetic. To produce an increased flow, the muscular fibres are relaxed by influence from the sensory nerves, apparently suspending or diminishing the action of the sympathetic ganglia. The gastric secretion in the stomach is influenced, probably in the same way, through the sensory nerve of the stomach, the pneumo-gastric. So, the flow of milk in the female breast is augmented by irritating the nipple. The floio of tears is increased when a foreign body enters the eyelids. The same effect is caused by a strong light; also by irri- tating the conjunctival, nasal, and lingual branches of the fifth nerve. When the flow is stimulated by the more remote disturbances of vomiting, violent coughing, laughing and sobbing, there is pro- bably an intermediate stimulation of the fibres of the fifth pair. The flow of tears under pain is a relief from the congestion of the brain, and may be forced on by that circumstance, and not by the process last described. The effect of pain is to weaken the direct cerebral impulses, and give more play to the sympathetic, so that the regular consequence is exemplified in the arrest of secretion (as, for example, the saliva and the gastric juice). The tvinking of the eye is a reflex act, following the same REFLEX :,IOVEMENTS IN THE EYE. -275 stimuli as the flow of tears ; namely, the presence of a foreign body, the accumulation of watery drops in the eye, and a strong light. The nerves of the fifth pair are the instrumentality ; and the paths of influence are partly sympathetic, partly cerebro-spinal (in this instance, probably issuing from the medulla oblongata). The complete and energetic closure of the eye, involving not only the eyelids, but also the eyebrows, is altogether voluntary. The movements of the iris are due to the sympathetic system, controlled by the sensory nerves of the eyeball, and the motor nerves of the eye. The iris is contracted under a strong light, and expanded as the light becomes feeble. If the process be conducted on the analogy of the foregoing examples, the sympa- thetic ganglia would control the radial fibres, which keep the eye open ; the abatement of this control by sensory action allowing the circular or contracting fibres to operate. It is possible, besides, that the fibres of the third cerebral nerve proceeding to the iris may be stimulated by a reflex influence of the light through some portion of the brain (as the corpora quadrigemina). In the Fourth, and last, class of reflex actions, muscles, more or less voluntary, are affected through the cerebro-spinal centres. Here we have an approximation to proper voluntary acts ; the stimulant in all cases being accompanied with sensa- tion, and the movement being such as the will could execute. The first case that we shall mention is the contraction of the ciliari/ muscle, in the adjustment of the eye to near vision. This action, without our consciously willing or wishing it, succeeds to the feeling of indistinctness of the picture when anything is brought nearer to us. Consentaneous with the act, are the nar- rowing of the pupil and the convergence of the eyes ; all the three adjustments co-operating to the distinct vision of near objects. The nerve for regulating the ciliary muscle is supposed to be a branch of the third pair ; the contraction of the iris may be due to the same nerve, which likewise governs the conver- gence of the eyes, through the internal rectus muscle. The nervous centre more immediately concerned is the anterior pair of the corpora quadrigemina, stimulated through the optic nerve. The muscles of the tyinpcmum are controlled in a manner analogous to the adjusting muscles of the eye. The analogy extends to the mixed supply of nerves ; those for the tensor 276 THE EEFLEX ACTIONS. tympani being derived from the sympathetic (hke the radial fibres of the iris), those for the stapedius from the fifth cranial nerve. On the theory of the action of these muscles that accords with the above analogy, the tensor tympani tightens both the membrane of the tympanum and the membranes of the foramina of the inner ear, under the influence of the sympathetic ganglia, and renders the ear susceptible, in the highest degree, to sound, like the radial fibres of the iris widening the pupil to the utmost. The feeling of sound in excess would then operate to relax those parts, by the stapedius muscle, which is stimulated through the facial (motor) nerve. Under the same head, we may place the reflex movements of the senses, generally. By these, are understood the special move- ments of the organ of sense itself, as distinct from the more diffused wave of influence accompanying lively sensation. Thus, an object placed in the hand specially stimulates the muscles that bend the fingers, besides producing the more distant effects associated with a sensation as a fact of consciousness. The effect may be seen in any one asleep. A bad smell affects specially the muscles of the nose ; a bitter taste brings on wry movements of the mouth. The word ' Eeflex,' as applied to the actions now considered, needs to be specially guarded and explained. It is employed in cases where its obvious meaning is absent,, and withheld in others where that meaning is present,* The notion plainly attached to the word is a circle of influence, wherein there can be distinctly shown an outer or peripheral stimulation, conveyed by incarrying nerves to a ganglionic centre, and bringing on, by way of response, certain movements. The stimulation may be unconscious, as in the intestines, or conscious, as in the adjustment of the eye. The distinction is an important one. It marks out two grades of the effect, a lower and a higher ; and distinct names have been employed to express the two — the * The term ' automatic ' is used as a synonym, or as a substitute, for ' reflex,' but with still less aptness for the purpose. It would serve to indi- cate the spontaneous activity, and that alone. With proper cautions and ex- planations, the name ' reflex ' is the most suitable that has yet been proposed. •Involuntary,' although applicable to the class (allowance being made for a margin of transition), is too wide in its meaning. LIMITS OF EEFLEX ACTION. 277 phrase excito-motor being applied to the first, and sensori-motor to the second. But it has been very properly remarked, that actions of the highest order of combined volition and intelligence may have this reflected character. Any one promptly answering a ques- tion, exemplifies a reflex operation, so far as the general meaning is concerned. But such cases are not included among the so- called Reflex actions ; these being set in marked contrast to voluntary actions of every kind. Again, there are included in the class certain effects that are obviously wanting in the peculiarity implied in the name ' reflex '. Thus, we have seen that there are many movements due solely or mainly to central influence, — the so-called spontaneous move- ments ; with regard to which, either no peripheral stimulus can be assigned, or the stimulus is insignificant compared with the energy of the response, an energy rising and falling with the physical condition of the central grey masses. The convulsive movements in certain ailments, as hydrophobia, hysteria, chorea, epilepsy, tetanus, etc., must be due to diseased changes in the condition of the nervous centres. These are involuntary move- ments, but they are not, strictly speaking, reflex. We may give a similar account of yawning ; which is, probably, due to the unequal subsidence of the nervous action, disturbing the balance of the muscular tension. It would be a very forced supposition, to bring it under the literal meaning of reflex action. In the enumeration of Reflex Actions, there is often included a group of effects distinct from any of the foregoing, — namely, those typified by laughter, cries, sobbing, sighing, starting, fidgets, etc. These have been sometimes styled sensori-motor, because they are at the instance of sensations. This circumstance, however, does not show their real characteristic. They are, in my opinion, more aptly brought under emotional diffusion, expression, or embodiment. Every conscious state is accompanied with a diffused wave of effects, muscular and organic, which is stronger according as the feeling is more intense. Pleasing emotions are attended with one class of manifestations, — the smile, for ex- ample ; states of pain with a difi'erent class. The leading emotions of the mind — Wonder, Fear, Love, Anger, etc. — have each a characteristic and well-known embodiment or display. 278 THE EEFLEX ACTIONS. These movements, incorporated in our constitution as a por- tion of the very fact of being conscious (we are often said to be ' moved,' when it is only meant that an impression is made on the mind), may be called ' sensori-motor,' inasmuch as a sensa- tion, when sufficiently powerful, always visibly stimulates them, rendering them, as it were, the return or response of the outward impression. They may, also, be styled 'relies,' for the veiy same reason. They are, further, ' involuntary ' movements, being quite distinct from our volitional acts. But they are far from being unconscious : they are, if I am not mistaken, inseparable from consciousness, being entwined with the conscious condition in the mechanism of our frame. When consciousness is feebly excited, so are they, — so feebly that no visible manifestation results ; when a stronger excitement is applied, they are roused in proportion. lu^ cultivated shape, thej" make the gesticulation and display that constitutes the usual expression or natural language of feeling, which no man and no people is devoid of, and some nations exhibit in a remarkable degree. Thfe painter, sculptor, poet, actor, seize hold of these movements as the basis of artistic forms ; and the interest of the human presence is greatly dependent on them, and on the attributes that result from them. Confining ourselves to the strictly Eeflex Actions, whether excito-motor, or sensori-motor, and omitting central spontaneity, emotional diffusion, and voluntary actions properly so called, we may now endeavour to generalize the facts, or to assign the most comprehensive laws at present attainable with regard to this pro- cess of the animal economy. I. We trace one comprehensive arrangement, of wide preva- lence throughout the animal kingdom, — namely, the connexion between a peripheral stimulus and the movement of the part affected. This is the simplest and the most generahzed type of the nervous system, demanding a circle made up of incarrying fibres, a central ganglion, and outcarrying fibres to the muscles of the same locality. In the lowest creatures possessing a nervous system, the structure and the function are as now- described. The fixed mollusc responds to a contact by a move- ment contracting its body. In the experiments on decapitated animals, irritation of the foot is followed by retracting or else throwing out the limb. MOST GENERAL LAWS OF REFLEX ACTION. 279 Notwithstanding the higher comphcations super-imposed upon this simple arrangement, it is shown, almost pure, in many of the actions above adverted to. The peristaltic movements of the intestines appear to be governed mainly by the contact with the part of the gut actually in movement. It is the same in the pharynx and oesophagus, and also in the rectum. In coughing, sneezing, and sucking, the first stage is a reflex stimulation to the muscles of the parts irritated. In the operation of the several senses, there is a reflex stimulus of the same character, although usually disguised and overpowered by the wider and more j)otent influences, respectively called emotional and volitional. We may readily speculate upon the mode of action in these simple reflex circles. The peripheral stimulation is either simple contact, as in the touch of a solid body, or contact with absorp- tion of material fitted to act on the nerves. In both cases, a muscular disturbance of the nerves takes place, which is propa- gated to the ganglia, and there reinforced by the more active changes occurring in the grey corpuscular matter ; whence arises a molecular movement in the outgoing or motor nerves. It is not every stimulation, however, that imparts or evolves molecu- lar activity : some stimulants, as cold, under certain circum- stances, tend to lower, reduce, or destroy activity already existing. The most potent stimuli, as we might expect, are nutritive ma- terials, and substances that, by combining with oxygen, or in other ways, generate force. The rise of temperature, in its direct or immediate consequences, contributes molecular power. II. One step above the simplest reflex movement, is the alternation of two movements, carrying the same part to and fro. \Yherever an organ is fitted with an opposing pair of muscles, both these have a connexion with the ganglion related to the part ; both receive outearrying fibres, and the local stimulus will excite movements in both — which movements, however, being opposed, must alternate with one another. It is an incident of such a situation that the muscles should fall into a reciprocating movement, and establish a nervous track inclining to this recip- rocation ; so much so, that the completed contraction of one, without any other stimulus, is an occasion of beginning a con- traction of the other. The alternating contraction of opposing pairs, whether in joint response to a peripheral stimulation, or as 280 THE KEFLEX ACTIONS. a result of mere spontaneity, or, lastly, as a consequence of re- mote nervous instigation, is a fact of very wide generality, and is the least possible remove from the simple reflex circuit supposed in the foregoing paragraph. III. The next advance in complexity is shown in the con- currence of several distinct movements in one act. Such a con- currence is required in deglutition, in sucking, in coughing, in forcible inspiration, in the adjustment of the eyes, and in loco- motion. The regulating circumstance of the united action is the furtherance of some end in the economy. We know by what means combined movements are acquired, in ordinary education; namely, by tentatives under the guidance of the desired effect. IV. The self-adjusting power now hinted at (to be afterwards fully elucidated in connexion with the Will) may be traced in the inferior region we have been considering. The supply of nutri- tion or other stimulus gives birth to molecular force, ending in muscular movement ; which movement, in many circumstances, furthers the nutritive or other contact, and is thereby still further stimulated, — as when the shell-fish in the sea opens its mouth to the water containing its food. In several of the reflex actions just described, consciousness is usually present ; as coughing, sneezing, sucking, the increased respiratory activity from cold, the reflex action of the senses, and the special adjustments of the ear and the eye. In so far as these actions arise during sleep, they may be regarded as independent of consciousness. But in some, consciousness is a part of the case — the object being, not to respond to a physical stimu- lation, but to remove an uneasiness; such are winking, and the adjustments of the eye to vision, and of the ear to sound. An obscure sense of discomfort is the antecedent circumstance in winking. To all these cases, we must apply the fundamental law of the will ; they contain the essential fact of volition. They differ from the more usual forms of voluntary action, only in not engrossing our attention ; we may be occupied with other matters while they are taking place. In this resj^ect, they re- semble actions in the stage of consummated habit. Yet, it is impossible to overlook the great resemblance to the course of voluntary action in those inferior reflex processes, commonly accounted devoid of consciousness. They are usually. LOCOMOTIVE RHYTHM. 281 although not always or necessarily, directed to the conservation of the individual, which is the foundation circumstance of con- scious and voluntary action. "When several movements are united in one act, as in sucking, this serves the better to answer some function of preservation. "We may not be able to draw a sharp line between the reflex involuntary and the voluntary : the two may shade into one another by insensible degrees ; and a common fact or tendency of the system may be at the foundation of both. THE PRIMITIVE COMBINED MOVEMENTS. 4. Of the primitive combined movements, in the human subject, the leading example is the locomotive rhythm. The instinctive character of locomotion, so obvious in the inferior animals, is less apparent in ourselves, seeing that the power of walking is not possessed by us until about a year after birth. Nevertheless, there are certain strong presumptions in favour of an original endowment entering into our aptitude for locomotion. (1) The analogy of the inferior quadrupeds countenances the probability of a locomotive rhythm in the human limbs. The similarity of structure of the vertebrate type is sufficiently close to involve such a deep peculiarity of the nervous system as this. What nature has done for the calf, towards one of the essential accomplishments of an animal, is not unlikely to be done in some degree for man. To equip a creature for walking erect would doubtless be far more difficult, and might surpass the utmost limits of the primitive structural arrangements ; but, seeing that the very same alternation of limb enters into both kinds, and that nature gives this power of alternation in the one case, we may fairly suppose that the same power is given in the other also. (2) It is a matter of fact and observation, that the alter- nation of the lower limbs is instinctive in man. I appeal to the spontaneous movements of infancy as the proof. Mark a child jumping in the arms, or lying on its back kicking ; observe the action of the two legs, and you will find that the 282 THE PRIMITIVE COMBINED MOVEMENTS. child shoots them out by turns with great vigour and rapidity. Notice, also, when it first puts its feet to the ground : long before it can balance itself, you may see it alternating the limbs to a full walking sweep. Only in virtue of this instinc- tive alternation is walking possible to be attained so soon. No other combination equally complex could be acquired at the end of the first year. Both a vigorous spontaneous im- pulse to move the lower limbs, and a rhythmical or alternating direction given to the impulse, are concerned in this very early acquisition. Let the attempt be made to teach a child to walk sideways at the same age, and we should entirely fail for want of a primitive tendency to commence upon. (3) It has been already seen, that the cerebellum is pro- bably concerned in the maintenance of combined or co-ordi- nated movements. AVe have proof that these movements can be sustained without the cerebral hemispheres, but hardly without the cerebellum. Now, that the cerebellum should be well developed in man, and yet not be able to effect those harmonized arrangements found in the inferior vertebrata, is altogether improbable. Unless some mode of invalidating these facts can be pointed out ,the reasonable conclusion will be, that there is in the human subject a pre-established adaptation for locomotive move- ments, — which adaptation we shall now attempt to analyze. 5. First, it involves the recipy^ocation or vibration of the limb. Confining ourselves to one leg, we can see that this swings to and fro like a pendulum ; implying that there is a nervous arrangement, such that the completed move- ment forward sets on the commencing movement backward, and inversely. The two antagonist sets of muscles con- cerned in walking are chiefly members of the two great general divisions of flexor and extensor muscles. Every moving member must have two opposing muscles or sets of muscles attached to it; and, between these, the limb is moved to and fro at pleasure. There is, obviously, an organized connexion between antagonist muscles generally, so as to give spontaneously a swinging or reciprocating movement ANTAGONISM OF MUSCULAE MOVEMENTS. 283 to the parts ; in other words, when any member is carried to its full swing in one direction, there is an impulse gener- ated and diffased towards the opposing muscles, to bri'ng it back, or carry it in the other direction. Of course, this reaction will be most strongly brought out on occasions when the commencing movement takes a wide and energetic sweep. Thus, in a swing of the arm carried up so as to point perpendicularly upward, we may discern an impulse in the opposing muscles to come into play in order to bring it down. Every swinging motion, whether of arm, leg, trunk, head, jaw, if not entirely due to volition, which it would be difficult to prove, must be supported by an arrangement of the nature now described.* * On the antagonism of muscular movements generally, I quote the following statements from Miiller : — ' There are groups of muscles opposed to each other in their action in almost all parts of the body. The extremities have flexors and extensors, supinators and pronators, abductors and adductors, and rotators inwards and rotators outwards. Frequently the opposed groups of muscles have different nerves. Thus the flexors of the hand and fingers derive their nervous fibrils from the median and ulnar nerves ; the extensors theirs from the radial nerve ; the flexors of the forearm are supplied by the musculo-cutaneous ; the extensors by the radial nerve. The crural nerve supplies the nervous fibres for the extensors of the leg ; the ischiadic those for the flexors. The peroneal muscles, which raise the outer border of the foot, derive their nervous fibres frouj the peroneal nerve ; the tibialis posticus, which raises the inner border of the foot, is supplied by the tibial nerve. The circumstance of the convulsive motions in afiections of the spinal cord being frequently such as to curve the body in a particular direction shows that there must be something in the disposition of the nervous fibres in the central organs which facilitates the simultaneous excitement to action of particular sets of muscles, as the flexors, or extensors, etc. ; although Bellingeri's opinion, that the anterior columns of the spinal cord sei"\-e for the motions of flexion, the posterior for those of extension, is based on no sufficient facts. Too much importance, however, must not be given to the above remark relative to distinct nerves suj^plying the different groups of muscles ; it is not a constant fact. Some- times the same nerve gives branches to muscles opposed in action ; the ninth, or hypo-glossal nerve, supplies both the muscles which draw the hyoid bone forwards, and one muscle which retracts it ; the peroneal nerve supplies the peroneal muscles, which raise the outer border of the foot, and the tibialis anticus, which opposes this motion. Antagonist muscles can, moreover, be most easily made to combine in action ; thus the peroneal muscles and the anterior tibial, acting together, raise the foot. The flexor carpi radialis and the extensor carpi radialis can combine so as to abduct the hand ' (p. 925). 284 THE PRIMITIVE COMBINED MOVEMENTS. In walking, there is also, of course, a pendulous swing of the leg, arising out of mere mechanical causes. Like any- other body hanging loose, the leg is really and truly a pen- dulum, and when thrown back begins to move forward of its own accord. Again, the extensor muscles, which maintain the body in an erect position, are antagonized by the weight of the parts; hence, in dancing up and down, the downward movement may take place by simply relaxing the tension of the supporting muscles. In the same manner, the jaw tends to drop of its own accord. 6. Secondly, there is implied in locomotion an alternate movement of corresponding limbs, or an alternation of the two sides of the body. After one leg has made its forward sweep, an impulse has to be given to the other leg to commence a movement in the same course. The two sides of the body must be so related, that the full stretch of the muscles of the one side originates a stimulus to those of the other. Nothing less would suffice to enable a new- born calf to walk. The alternation between the right and left legs, both fore and hind, must be firmly established in the animal's organization by a proper arrangement of the nerves and nerve centres. And, if the power of walking in human beings be assisted by primitive impulses and ar- rangements, this specific provision is necessarily implied. The alternation of the two sides in locomotion extends beyond the muscles of the limbs : the whole trunk and head sway in harmony with the members, both in quad- rupeds and in man. There are some important exceptions to this alternating arrangement ; but these are of a kind to place in a stronger light the examples of it now quoted. The two eyes are made to move together, and never alternate. This ar- rangement is the most prominent, bat not the only, example of associated simultaneous movements. It has, doubtless, to do with the unity and singleness of the act of vision. Moreover, if we observe the early movements of the arms in children, we shall find in them more of the tendency to ASSOCIATED OR CONSENSUAL MOVEMENTS. 285 act together than to alternate ; showing, as we might otherwise infer, that the impulse of alternation of the limbs is not so deep-seated an instinct in man as in quadrupeds. In like manner, the movements of the features are, for the most part, the same on both sides of the face. 7. Thirdly. The locomotion of animals moving on all fours suggests a further necessity of primitive adjustment. It is requisite that there should be some provision for keep- ing the fore and hind legs in proper relation and rhythm. Something of the nature of the vermicular movement (that is, the locomotion of worms), or the movements of the alimen- tary canal, needs to be assumed in this case. Such a con- nexion must exist between the fore and hind segments, in order that the movements of the one may stimulate in suc- cession the movements of the other, by a nervous propagation along the spinal cord to the cerebellum, or other centre gov- erning the primitive rhythmical motions. In the crawling of reptiles, it is obvious that the muscular contraction in one segment or circle must yield a stimulus to a nerve in con- nexion with the next circle, which is made to contract in consequence, and furnish a stimulus to the third, and so on through the whole line of the body ; the action of the intes- tines being almost the same. In a dog, we see the move- inent of the limbs propagated to the tail. Each species of animal has its particular formula of ordering the legs in walking, determined, it may be, in part by the shape of the body, but duly transmitted in the breed as a property of its structure. The shamble of the elephant represents one spe- cies of rhythm ; while the horse can pass through all the varieties of walk, gallop, and canter. In climbing, too, the alternation and the propagation both come into play as helps. In swimming, both are likewise apparent. 8. I must now mention more particularly the associated or consensual movements, or those that are so connected as to occur together. The most perfect example of this is in vision. In order to make the two eyes act together, the 286 THE PEIMITn^E COMBINED MOVEMENTS. corresponding muscles of each must be simultaneously excited by the nerves. The following are the facts con- nected with this interesting case. I quote from Miille'r. ' Some of the most remarkable facts illustrating the association and antagonism of muscular actions, are presented by the muscles which move the eyes. The corresponding branches of the third, or motor oculi, nerve of the two sides have a remarkable innate tendency to consensual action, a tendency which cannot be ascribed to habit. The two eyes, whether moved upwards, downwards, or inwards, must always move together ; it is quite impossible to direct one eye upwards and the other downwards at the same time. This tendency to consensual action is evi- denced from the time of birth ; it must therefore be owing to some peculiarity of structure at the origins of the two nerves. The association in action of the corresponding branches of the two nervi motores oculi, renders the absence of such tendency to consensual motion in the two external recti muscles and the sixth nerves more striking. We do, it is true, in a certain measure cause the two external recti muscles to act together when we restore the two eyes, of which the axes are converging, to the parallel direction ; but there the power of consensual action ends ; the two eyes can never be made to diverge, however great the effort exerted to do so. There is an innate tendency and irresistible impulse in the corresponding branches of the third nerve to associate action ; while in the sixth nerves not only is this tendency absent, but the strong action of one of these nerves is incompatible with the action of the other. These innate tendencies, in the third and sixth nerves, are extremely important for the functions of vision : for if, in place of the sixth nerves, the external recti muscles had received each a branch of the third nerve, it would have been impossible to make one of these muscles act without the other ; one eye, for example, could not have been directed inwards while the other was directed outwards, so as to preserve the parallelism, or con- vergence of their axes ; but they would necessarily have diverged when one rectus externus had been made to act voluntarily. To render possible the motion of one eye inwards, while the other is directed outwards, the external straight muscles have received ASSOCIATED MOVEMENTS IK THE EYE. 287 nerves which have no tendency to consensual action. In conse- quence, however, of the tendency in the two internal straight muscles to associate motion, it is necessary when one eye is directed inwards and the other outwards, that the contraction of the rectus externus of the latter should be so strong as to over- come the associate action of the rectus internus of the same eye ; and in the effort to direct one eye completely outwards, we actually feel this stronger contraction of the external rectus. These considerations enable us to imderstand perfectly the hitherto enigmatical fact that, in al] vertebrata, the external rectus muscle receives a special nerve' (p. 929). The author then goes on to show the relation of the corresponding oblique muscles to each other, and the simi- lar reason there is for having a distinct nerve to the superior oblique or trochlear muscle. An association exists between the adjustment of the iris and the other movements of the eye : thus, whenever the eye is voluntarily directed inwards, the iris contracts. Hence the fact already stated, that the iris is contracted during near vision. Muller also remarks that ' the motions very prone to be associated involuntarily, are those of the corresponding parts of the two sides of the body. The motions of the irides, of the muscles of the ear, of the eyelids, and of the extremities, in the attempt to effect opposed motions, are examples of such associations.' I have already remarked that this coin- cidence of movements on the two sides co-exists, in the case of the limbs at least, with an organization for an alter- nating motion. The same author further observes, that ' the less perfect the action of the nervous system, the more frequently do as- sociated members occur. It is only by education, that we acquire the power of confining the influence of volition, in the production of movements, to a certain number of nervous fibres issuing from the brain. An awkward person, in per- forming one voluntary movement, makes many others, which are produced involuntarily by consensual nervous action' 1^ 288 THE PRIMITIVE COMBINED MOVEMENTS. (p. 928). This, however, introduces much larger considera- tions, involving the whole mechanism of emotion and voli- tion. 9. There are various appearances that suggest the ex- istence of a law of general harmony of state throughout the muscular system. In stretching the lower limbs, we feel at the same time an impulse to stretch the arms, the trunk, the head, and the features, or to put in action the whole class of extensor or erector muscles. The act of yawning propagates a moveinent over the whole body. I cannot positively afhrm that this may not be explained by similar- ity of state producing everywhere a similar impulse ; but the appearances are more in favour of a harmony of con- dition produced through the nervous system. When the eye is gazing attentively on an object, the whole body is spontaneously arrested, the features are fixed, the mouth is open ; and the same harmonizing fixity is observed in the act of listening. So, a movement in one part propagates itself to other parts, unless a special check is maintained ; the movements of the eye excite the whole body. Vocal utterance brings on gesticulation. The pace of movement is also rendered harmonious. Eapid movements of t"he eye from exciting spectacles make all the other movements rapid. Slow speech is accompanied by languid gestures. In rapid walking (before the exercise has a derivative effect on the brain), the thoughts are quickened. These movements are to be ranked among the primitive impulses that serve the useful ends of the animal ; they count among the ^r(XC^*ca,Z instincts now under discussion. They cause the animal to come into harmony with the circum- stances that surround it, — to be quiet when the scene is still, to start up and join when others are stirring. This property imparts character to individuals. A person is either slow or vivacious, generally ; the cast of movement is the same in all organs, in action and in thought. From it arises, likewise, a means of rousing and controlling the actions, thoughts and passions, of men and animals. ONE SENSE ACTING FOR ANOTHER. 289 In the cries of human beings and animals, which is a part of the expression of feehng, there is a primitive combi- nation or concurrence of movements, remarkable for its uni- formity. The tension of the vocal cords, through the laryn- geal muscles, the forced expiration, and the adjustment of the mouth, are united in the same act. Possibly, these are concurring effects of the emotional wave, or the diffused stimulus of strong feeling, to be noticed presently. 10. There are certain cases where one sense can appa- rently act for another, previous to experience, — as when an animal detects wholesome or unwholesome food by the smell before tasting it. That the sense of taste should inform us of what is good for digestion (which it does to an imperfect degree in the human subject), is not surprising, seeing that, in the mouth, the alimentary canal is already com- menced : we feel more difficulty in discovering how smell should have this power of anticipating digestion and nutri- tion. The effluvia that bodies emit to the nostrils, may be a specimen or representative of their substance as applied to the stomach, and may have something of a like effect on the nervous system. AVe know that the smell of putridity causes loathing and disgust, a.nd that an attempt to eat such material would only complete the effect already begun ; while, on the other hand, substances that have a sweet or fresh flavour, would, in all probability, be free from nausea in the stomach. On the general fact of one sense acting for another by way of warning or invitation, it is to be remarked that a deep harmony appears to exist among the different senses, — in consequence of which we apply common epithets to the objects of all of them. Thus, the effect we call ' freshness,' determined by the stimulus of the lungs, the digestion, or the general nervous tone, arises in several of the senses. The difficulty is to find the same external object, acting in the same manner upon two or more of them, as in the case of discerning food by the sight, or by the smell. I am of opin- io 290 THE INSTINCTIVE PLAY OF FEELING. ion that these coincidences, recognized before experience, are very few in number, and that the great safeguard of animals hes in making the direct experiment of eating what comes in their way, and in deciding according to the feel- ings that result therefrom.* Among concurrences in Sensation, there may also be noticed the facts known as the transference, radiation, and reflexion of sensations. Eeference has already been made (Reflex Actions, p. 250) to the tendenc}^ of violent nervous stimulation to extend its sphere into collateral tracks. There are certain cases of definite and uniform transference of the seat of a sensation to a distant locality. In disease of the hip, the pain is felt in the knee ; when the kidney is the seat of irritation, the feeling of pain may be localized in the heel ; certain diseases of the brain are accompanied with pains in the limbs (Marshall's Physiology, vol. i. p. 347). THE INSTINCTIVE PLAY OF FEELING. 11. In following out our present object, winch is to pass in review all that is primitive among the seusibilities and the activities of the mental system, we shall next consider the instinctive or original mechanism for the expression of Feeling. -f- It is well known that some of the most con- spicuous among the manifestations of human feeling, as * It is a fact that lambs coniuaeuce eating, not the short tender grass, but the long and dried tops. 1 1 have already referred (see p. 258) to the general law which I believe connects together emotion, or feeling, and those physical activities of the frame known as the expression or manifestation of feeling. The movements and display caused by mental excitement have been commonly regarded as merely incidental to certain of the stronger feelings, and little attention has been paid to them in the scientific consideration of the mind. For my own part, however, I look upon these active gestures as a constituent part of the complex fact of consciousness, in every form and vai-iety. I do not saj' but we may have feelings that do not give rise to any visible stir of the active members, either inconsequence of voluntary suppression, or because the dif- fused stimulus is too weak to overcome the inertia of the parts to be moved, — but I mean to affirm that xoith feeling there always is a freely diffused current of nervous activity, tending to produce movements, gesture, expres- sion, and all the other effects described in the course of the next few pages (see ' The Emotions and the Will,' Emotions, chap. i. jj 2). NEEVES OF EXPEESSION OF THE FEATURES. 291 laughter and tears, belong to us from our birth. Education here finds work in repressing original impulses, no less than in imparting new and artificial forms of emotional display. It will be instructive to quote the section devoted to this subject in Miiller's Physiology. The professed title of the section is, Movements due to the Passions of the Mind. ' It is principally the respiratory portion of the nervous system which is involuntarily excited to the production of mus- cular actions by passions of the mind. Here again we see that a,ny sudden change in the state of the brain, propagated to the medulla oblongata, immediately causes a change of action in the respiratory muscles, through the medium of the respiratory nerves, including the respiratory nerve of the face. There are no data for either proving or refuting the hypothesis, that the passions have their seat of action in a particular part of the brain, whence their effects might emanate. But these effects are observed to be transmitted in all directions * by the motor nervous fibres, which, according to the nature of the passion, are either excited or weakened in action, or completely paralysed for the time. ' The exciting passions give rise to spasms, and frequently even to convulsive motions affecting the muscles supplied by the respiratory and facial nerves. Not only are the features dis- torted, but the actions of the respiratory muscles are so changed as to produce the movements of crying, sighing, and sobbing. Any passion of whatever nature, if of sufficient intensity, may give rise to crying and sobbing. Weeping may be produced by joy, pain, anger, or rage. During the sway of depressing pas- sions, such as anxiety, fear, or terror, all the muscles of the body become relaxed, the motor influence of the brain and spinal cord being depressed. The feet will not support the body, the features hang as without life, the eye is fixed, the look is completely vacant and void of expression, the voice feeble or extinct. Fre- quently the state of the feelings under the influence of passion is of a mixed character ; the mind is unable to free itself from the depressing idea, yet the effort to conquer this gives rise to an excited action of the brain. In these mixed passions the expres- * Italics mine. 292 THE INSTINCTIVE PLAY OF FEELING. sion of relaxation in certain muscles, — in the face, for example, — may be combined with the active state of others, so that the features are distorted, whether in consequence merely of the antagonising action of the opposite muscles being paralysed, or by a really convulsive contraction. Frequently also, both in the mixed and the depressing passions, some muscles of the face are affected with tremors. The voluntary motion of a muscle half paralysed by the influence of passion is frequently of a tremulous character, in consequence of its being no longer completely under the influence of the will. We experience this particularly in the muscles of the face, when, during the sway of a depressing or mixed passion, we endeavour to excite them to voluntary action; the muscles of the organ of voice also, under such circumstances, tremble in their action, and the words attempted to be uttered are tremulous. ' The nerve most prone to indicate the state of the mind diu-ing passion is the facial ;* it is the nerve of physiognomic expression, and its sphere of action becomes more and more limited in different animals, in proportion as the features lose their mobility and ex- pressive character. In birds, it has no influence on the expression of the face ; those only of its branches exist which are distributed to the muscles of the hyoid bone and the cutaneous muscle of the neck ; and the erection of the skin of the neck, or, in some birds, of the ear feathers, is in them the only movement by which the facial nerve serves to indicate the passions. Next to the facial, the respiratory nerves, — those of the internal organs of respira- tion, the laryngeal and phrenic nerves, + as well as those of the external thoracic and abdominal muscles — -are most susceptible of the influence of the passions. But when the disturbance of the feelings is very intense, all the spinal nerves become affected, to the extent of imperfect paralysis, or the excitement of trembling of the whole body. ' The completely different expression of the features in different passions shows that, according to the kind of feeling excited, en- * 'The facial nen-e is the motor nerve of the face. It is distributed to the muscles of the ear and of the scalp ; to those of the mouth, nose, and eyelids ; and to the cutaneous muscles of the neck.' t The laryngeal nerves are distributed to the different parts of the larynx, and are, therefore, instrmnental in stimulating the voice. The phrenic, or diaphragmatic nerve, is the special nerve of the diaphragm. MOVEMENTS OF EXPRESSION. 293 tirely different groups of the fibres of the facial nerve are acted on. Of the cause of this we are quite ignorant. 'The disturbed action of the heart during mental emotions is a remarkable instance of the influence of the passions over the move- ments of organs supplied by the sympathetic nerve ' (pp. 932-4). 12. With regard to the Movements of the Face, Sir Charles Bell is of opinion that many of them are secondary to the movements of respiration. He regards the heart and the lungs as the great primary sources of expression — the organs first affected by the emotional excitement of the brain. He called attention to ' the extent of the actions of respiration, che remoteness of the parts agitated in sympathy with the heart. The act of respiration is not limited to the trunk ; the actions of certain muscles of the windpipe, the throat, the lips, the nostrils, are necessary to expand those tubes and openings, so that the air may be admitted through them in respiration with a fi'eedom corresponding to the increased action of the chest. Without this, the sides of these pliant tubes would fall together, and we should be suffocated by exertion or passion. Let us consider how many muscles are combined in the single act of breathing — how many are added in the act of coughing — how these are changed and modified in sneezing ; — let us reflect on the various combinations of muscles of the throat, windpipe, tongue, lips, in speaking and singing,* and w^e shall be able justly to estimate the extent of the muscles w^hich are associated with the proper or simple act of dilating and compressing the chest. But how much more numerous are the changes wrought upon these muscles when nature employs them in the double capacity of communicating our thoughts and feelings ; not in the language of sounds merely, but in the language of expression of the countenance also ; for certainly the one is as much their office as the other.' ' Let us see how the machine works. Observe a man threat- ened with suffocation : remark the sudden and wild energy that pervades every feature ; the contractions of the throat, the gasp- ing and the spasmodic twitchings of his face, the heaving of his chest and shoulders, and how he stretches his hand and catches * These, howevei', are not primitive or instinctive associations, the class that we are most interested in tracing out at present. 294 THE INSTINCTIVE PLAY OF FEELING. like a drowning man. These are efforts made under the oppres- sive intolerable sensation at his heart ; and the means which nature employs, to guard and preserve the animal machine, giving to the vital organ a sensibility that excites to the utmost exertion' (Anatomy of Expression, 3rd edition, p. 91). This last illustration does not decide the point as to the dependence of the contortion of the features upon the respi- ratory organs, inasmuch as the state of intense pain supposed would excite every part of the body by direct action. The previous remarks on the necessity there is for movements of the respiratory passages, — the throat, mouth, and nostrils, — to accompany the action of the lungs, are very much in favour of the author's view. But that the action on the face is not wholly a conse- quence of respiratory excitement, is decisively proved by the expression of the eyes ; for, this in no way ministers to the breathing function. AVe are, therefore, led to conclude that, while a certain amount of the facial expression is due to the sympathy or association of the parts of the movements of the lungs, there still remains a source of independent ex- citement derived from the brain at first hand, and through the same common impulse that affects the respiratory, the vocal, and other organs. This distinctness of action is re- cognized in the passage quoted from Miiller. 13. In tracing out systematically and minutely the physi- cal accompaniments of states of feeling, there is observable a broad and fundamental division into two classes — namely, effects of movement through the muscular system, and organic effects, or the influences exerted upon the viscera and glandu- lar organs. Let us consider first the Movements. We find certain muscles more particularly acted on under feeling, and named, for that reason, muscles of Expression. Of the more susceptible muscular regions, our attention is specially called to the Face. The muscles of the face, whereby all the movements are sustained, are arranged round three distinct centres, — the MUSCLES OF THE EYEBROW. 295 P]yes, the Nose, and the Mouth. The month has the largest number of muscles, and is the most easily affected by states of feeling. The nose is the least endowed with mobility. The muscles of the Eyebrow have been already pointed out. The occipito-frontaUs descends over the forehead, and is inserted into the eyebrow ; this it raises or arches. It is opposed by the corrugatoi' siijjercilii, which corrugates or wrinkles the forehead, drawing the eyebrows together. These are pre-eminently muscles of expression, although also employed as voluntary muscles for the purposes of vision. They are emotionally moved by opposite states of feeling, the one in the more pleasing emotions, the other in pain, doubt, and embarrassment ; and the appearance that they cause to a spectator suggests, by association, the corre- sponding states of mind. The orbicular muscle of the eyelids, which closes the eye, is of the nature of a sphincter, like the muscle surrounding the mouth, and constituting the lips. This is opposed by the levator palpehrce, or the elevating muscle of the upper eyelid, which opens the eye, both voluntarily, and under emotion. The tensor tarsi ' is a very thin, small muscle, placed at the inner side of the orbit, resting against the fibrous covering of the lachrymal sac, and behind the tendon of the orbicularis.' ' The corrugator muscle, being fixed at its inner extremity, draws the eyebrow and eyelid inwards, and throws the skin into perpendicular lines or folds, as in frowning. The occipito-frontalis will, on the contrary, elevate the brow, and wrinkle the skin transversely ; which actions are so frequently repeated by most persons, and so constantly by some of a particular temperament, that the skin is marked permanently by lines in the situations just referred to. The orbicular muscle is the sphincter of the eyelids. It closes them tirmly, and at the same time draws them to the inner angle of the orbit, which is its fixed point of attach- ment. The levator palpebrte is the direct antagonist of the orbicular muscle ; for it raises the upper eyelid, and uncovers the globe of the eye. The tensor tarsi draws the eyelid towards the nose, and presses the orifices of the lachrymal ducts close to the 296 THE INSTINCTIVE PLAY OF FEELING. surface of the globe of the eye. It may thus faciUtate the entrance of the tears into the ducts, and promote their passage towards the nose ' (Quain). 14. The muscles of the Nose are, first, the pyramidal, ' which rests on the nasal bone, and appears like a prolon- gation of the occipito-frontalis, with whose fibres it is inti- mately connected. It extends from the root of the nose to about half-way down, where it becomes tendinous, and unites with the compressor naris. Its chief effect seems to be that of giving a fixed point of attachment to the frontal muscle ; it also wrinkles the skin at the root of the nose.' The common elevator of the Up and nose lies along the side and wing of the nose, extending from the inner margin of the orbit to the upper lip. It raises the wing of the nose and the upper lip together. The compressor naris ' is a thin, small triangular muscle, which lies close upon the superior maxilla and the side of the nose, being transverse from without inwards and up- wards '. Contrary to its name, the principal action of it must be to expand the nostril by raising the lateral cartilage. This is an action in obvious harmony with respiration, seeing that it opens the nasal passage. The depressor aloe nasi ' is a small flat muscle, lying be- tween the mucous membrane and the muscular structure of the lip, with which its fibres are closely connected '. Of these and other bundles of muscular fibres, traceable on the small cartilages of the nose, the only considerable or powerful muscle is the Common Elevator of the lip and nose, which is thoroughly under the command of the will, and produces a very marked contortion of feature, wrinkling the nose and raising the upper lip. In expressing disgust at a bad smell, this muscle is strongly brought into play ; and thence it comes to be employed in expressing" disgusts gener- ally. It is, however, employed without any such intention. 15. There are nine muscles connected with the move- ments of the Mouth. One of them, the orbicularis, is single, MUSCLES OF EXPEESSIOX OF THE MOUTH. 297 and surrounds and forms the aperture itself; the other eight are pairs, and radiate from this as from a centre. The proper elevator of the upper lip extends from the lower border of the orbit to the upper lip, lying close to the border of the common elevator of the lip and nose. AVhen the lip is raised without raising the nose, which is not a very easy act, this muscle is the instrument. The elevator of the angle of the mouth ' lies beneath the preceding, and partly concealed by it '. ' The zygomatici are two narrow fasciculi of muscular fibres, extending obliquely from the most prominent point of the cheek to the angle of the mouth, one being larger and longer than the other.' The elevator of the angle of the mouth, and the zygomatic muscles, serve to retract the angle of the mouth in smiling ; they are, therefore, muscles of expression. The two first of these four muscles are concerned in raising the upper lip ; but they do not act very powerfully, or conspicuously. In fact, the upper lip is a feature re- markable for fixity, as compared with the under lip, and is not often elevated in man ; and, on the occasions when it is raised, this is done by the common elevator rather than by its own proper muscles. The region of the lower jaw contains three muscles, — the depressor of the angle of the mouth, the depressor of the lower lip, and the elevator of the lower lip. The depressor of the angle of the mouth lies at the side and lower part of the face, being extended from the angle of the mouth to the lower jaw. The depressor of the lower lip is a small square muscle, lying nearer to the middle line of the chin than the pre- ceding, by which it is partly concealed. It rises from the fore part of the lower jaw-bone, and is inserted into the lower lip ; its fibres become blended with those of the orbicular muscle of the mouth, having been previously united with those of its fellow on the opposite side. The elevator of the lower lip arises from a slight pit below 298 THE INSTINCTIVE PLAY OF FEELING. the teeth-sockets of the lower jaw, near the middle hue of the jaw, and is inserted into the tegument of the chin, which it hfts when in action. The remaining muscles of the mouth are unconnected with either jaw, having a sort of middle position between them. ' At each side of the face, in the part called the " cheek, '^ is a muscle — the buccinator ; and, round the margin of the mouth, one — the orbicularis oris.' ' The buccinator is a thin, flat plane of muscular fibres, quadrilateral in figure, occupying the interval between the jaws.' This muscle is exerted in masticating the food, and receives nerves from the same source as the masseter, which is one of the principal muscles engaged in the act of mas- tication. The orbicularis oris ' belongs to the class of sphincter muscles, and, like them, is elliptic in form, and composed of concentric fibres, so placed as to surround the aperture of the mouth : but with this peculiarity, that the fibres are not continued from one lip into the other. The muscle is flat and thin ; its inner surface being in contact with the coronary artery of the lips, labial glands, and the mucous membrane ; the external with the skin and the fibres of the different muscles which converge towards the margin of the mouth.' ' The aperture of the mouth is susceptible of considerable dilatation and contraction ; the former being affected by the different muscles which converge to it, and which may be com- pared to retractors drawing, with different degrees of obhquity, the lips, or their angles, in the direction of their respective points of attachment. The elevators are necessarily placed at the upper part of the face, the depressors in the opposite situation, and the proper retractors on each side ; and these are the zygomatici and the buccinators. The buccinators also contract and compress the cheeks ; this power is brought into play when any substance becomes lodged in the interval between them and the jaws.' 16. But it would be a mistake to confine the wave of ORGANIC EFFECTS OF FEELING. 299 movement to the Face, although this is the region where it is pre-eminent. The Voice acts in concert ; giving forth sounds that are characteristically different under joy or woe, affection or rage. (The mechanism of the vocal organs is described in a separate section.) x\mong muscles specially affected under mental states, we should not omit the Diaphragm. All the muscles of the body may be thrown into agita- tion under a wave of strong feeling ; the movements, gesti- culations, and carriage of the frame at any one moment are confidently referred to as proof of a certain emotional state. In Joyful moods, an abundance of gesticulation is often dis- played, in company with the play of the features and the voice. In Sorrow, there is sometimes a wild frantic excite- ment ; but more commonly we observe the inaction and collapse of the moving members generall3^ In Wonder, there is apt to be a liveliness of movement ; so in Rage ; while a tremulous quaking is the characteristic of Fear. 17. I must, next, advert to the Organic effects of emotion, which are quite equal in point of importance to the muscular. The viscera and glandular organs that are known to be the most decisively acted on are the following : — (1) The Lachrymal Gland and Sac. The Anatomy of this part has been adverted to in speaking of its associated organ, the Eye. The existence of the lachrymal gland and sac in our structure is a fact anterior to the supposed evolution of facial expression and the emotional outbursts of joy and sorrow. Darwin has attempted to assign a series of stages in this evolution, whereby he comes, in the end, to render a reason for the sorrowful side at least of the expression of the face. It is a safe assumption to begin with the physical use of the lachrymal secretion as a pro- tector of the eye in a variety of circumstances. The foremost and most prevalent of such occasions is the occurrence of dust particles on the surface of the eye, whose undisturbed persistence would be injurious. In the act of riddance of such extraneous substances, tliere participates the sensitive character of the inner 300 THE INSTINCTIVE PLAY OF FEELING. surface of the eyelids. Wheu this surface is affected by the contact of a strange body, it is acutely painful ; and a reflex action stimulates the flow of tears to wash it away — an effect that pro- bably arises without, as well as with, a painful sensation. No earlier or antecedent operation upon the gland can be assigned. Yet, it is a very long way from this to the lachrymal effusion that accompanies our various feelings and emotions, and the inter- mediate steps are not easy to assign upon full evidence. As the gland, like all other glands, is perpetually working, although in ver}- unequal degrees of copiousness, there must be a perpetual mode of escape for the secreted fluid. This escape is furnished through the outpouring of the exuded liquid over the eyeballs, and thence into the nose ; there being no visible drops upon the eyeball. A very pertinent question arises — Whether, as in many other glands, there be a special mode of sensibility, pleasurable or painful, connected with this secretion, at least in its exceptional degrees or amount? This consideration is not everything, as regards the theory of its operation ; but it is some- thing. Whether as relieving undue pressure on the brain, or as a gentle titillation to a highly sensitive surface, we niay not unreasonably suppose that it is in normal circumstances a cause of pleasurable sensation — a fact of the greatest relevance in accounting for its emotional value. That it should be more often brought into pla}' in painful than in pleasurable states, instead of being an objection, is a confirmation of this view. W^e may take for granted that, for assuaging pain, we resort to some one or otlier of our sources of pleasure. Without, at this stage, following Darwin's elaborate steps of sequence by which the secretion of tears becomes the key to facial expression, we know that, besides numerous forms of pain, the tender emotion is especially liable to be accompanied with this secretion. It may also accompany excessive joy ; while it is repugnant to the more energetic phases of mind, and especially to angry and malevolent outbursts. In the analysis of convul- sive sobbing, it has also to be reckoned with. (2) The Sexual Organs. These organs are both sources of feeling when directly acted on, and the recipients of influence from the brain, under many states of feelin/^ other- EFFECTS OX DIGESTION. 301 wise arising. They are a striking illustration of the fact that our emotions are not governed by the brain alone, but by that in conjunction with the other organs of the body. No cerebral change is known to take place at puberty ; nevertheless, a grand extension of the emotional suscepti- bilities is manifest at that season, x^lthough the organs may not receive their appropriate stimulation from without, the mere circumstance of their full development, as an additional echo to the nervous waves diffused from the cerebrum, alters the whole tone of the feelings of the mind, like the addition of a new range of pipes to a wind instrument. It is the con- tribution of a resonant, as well as of a sensitive, part. (3) The Digestive Organs. These have been already fully described ; and their influence upon the mental state has also been dwelt upon. In the present connexion, we have to advert more particularly to the reciprocal influence of the mind upon them. It may be doubted whether any consider- able emotion passes over us without telling upon the pro- cesses of digestion, either to quicken or to depress them. All the depressing and perturbing passions are known to take away appetite, to arrest the healthy action of the stomach, liver, bowels, etc. A hilarious excitement, within limits, stimulates those functions ; although joy may be so intense as to produce the perturbing effect — in which case, however, it may be noted that the genuine charm or fasci- nation is apt to give place to mere tumultuous passion. The influence of the feelings in digestion is seen in a most palpable form in the process of Salivation. In Fear, the mouth is parched by the suppression of the flow of the saliva — a precise analogy to what takes place with the gastric juice in the stomach. An equallj' signal example, in the same connexion, is the choking sensation in the throat during a paroxysm of grief. The muscles of the pharjiix, which are, as it were, the beginning of the muscular coat of the alimentary canal, are spasmodically contracted. The remarkable sensibility of this part during various emotions, is to be considered as I 302 THE INSTINCTIVE PLAY OF FEELING. only a higher degree of the sensibihty of the intestine generally. The sum of the whole effect is considerable in mass, although wanting in acuteness. In pleasurable emotion even, a titillation of the throat is sometimes perceptible. (4) The Skill. The cutaneous perspiration is liable to be acted on during strong feelings. The cold sweat from fear or depressing passion, is a sudden discharge from the sudorific glands of the skin. We know, from the altered odour of the insensible or gaseous perspiration during strong excitement, how amenable the functions of the skin are to this cause. It may be presumed, on the other hand, that pleasurable elation exerts a genial influence on all those functions. A similar line of remark would apply to the Kidneys. (5) The Heart. The propulsive power of the heart's action varies with mental states, as well as with phj^sical health and vigour. Some feelings are stimulants to add to the power ; while great pains, fright, and depression reduce the action. Miiller remarks above, that the disturbance of the heart is a proof of the great range of an emotional wave ; or its extending beyond the sphere of the cerebral nerves to parts aifected through the sympathetic nerve. (6) The Lungs. The quotations before given, from Miiller and Bell, sufficiently express the influence of emo- tional states on the movements of respiration. Tlie im- mediate effect of increasing or diminishing the movements will be to increase or to diminish the rate of exchange of the two gases — oxj'gen and carbonic acid — at the surface of the lungs. We cannot show^ that this exchange is influ- enced, through the nerves, otherwise than by the altered energy of the breathing movements. (7) The Lacteal Gland in woman. Besides the six organs now enumerated as common to the two sexes, we must reckon the speciality of women, — namely, the Secretion of the Milk. Like all the others, this secretion is genial, comfortable, and healthy, during some states of mind, while GENEEAL PRINCIPLE OF EMOTIONAL EXPRESSION. 308 depressing passions check and poison it. iVs an additional seat of sensibility, and an additional resonance to the dif- fused wave of feeling, the organ might be expected to render the female temperament to a certain degree more emotional than the male, especially after child-bearing has brought it into full play. The foregoing enumeration of organs that apparently take part in the expression or manifestation of feeling is to be regarded as a preparation for the announcement of the law or laws that associate our feelings in their sub- jective character with the allied physical embodiments and displays. It is as facts of Pleasure and Pain, in the first instance, that we study and generalize the physical workings of our conscious states. Although there are modes of ex- citement neither pleasurable nor painful, the workings of these would readily be made to grow out of the others. The associates of a physical kind with purely intellectual activities must receive a treatment apart. 18. We have before us two distmct aspects of the connexion of feeling with physical embodiments or workings. In the first place, there are the physical Agents with their immediate effects on the Sense Organs to begin with, to be followed by other effects on the Nerves proper ; the one class open to observation, and the other more or less, if not entirely, hypothetical. Secondly, we have the physical outcome in the form of the various movements and changes constituting expression or external display. A considerable number of the facts may be brought under the following principle, — namely, that states of pleasure are connected witJi an increase, and states of pain with an abatement, of some, or all, of the vital functions. Let us, first, revert to the known Agents, or stimulants, of pleasurable feeling, and compare them with their opposites. Beginning with the muscular Feelings, we know that exercise is pleasurable only when we are expending surplus energy, and thereby making the blood to course through the system more rapidly. Both the heart and the lungs are 304 THE INSTINCTIVE PLAY OF FEELING. quickened by bodily exercise ; while an accumulation of force, which it would be painful to restrain, finds a vent. Let the stage of fatigue, however, be reached, and let the spur to exertion be still continued, we then witness the concurring circumstances of the sense of pain and the lowering of xital energy. AVhen exercise is prolonged to the point of painful fatigue, there is an actual diminution in the amount of carbonic acid given off by the lungs, showing an enfeebled respiration. The action of the heart is, likewise, enfeebled ; and thus, upon two vital organs, has fallen an abatement of energy. It is equally certain that, in the same circumstances, the digestive power is reduced. Then, as to Muscular Eepose — a feeling highly pleasurable, especially if the amount of exercise has been well adjusted to the strength, — the generalization is not less applicable. What happens in resting after exertion is evidently this : — The muscles have expended all their surplus energy, and, in so doing, have stimulated several of the vital functions, such as the Heart, the Lungs, and the Skin. The Digestive function is not directly quickened under exercise, but rather retarded by the concentrating of the nervous currents in the muscles. Still, much good has been effected by the exalted operation of these other organs ; and now, at the stage of repose, the power hitherto compelled into one exclusive direction, being set free, returns to the other parts, and especially to the Digestive functions, — whose exaltation, through that circum- stance, coincides with the pleasant sensibility of the resting posture. Thus, while, in Eepose, we have the cessation of one vital energy, a corresponding increase takes place in several others : the organic functions generally are heightened, as the mental and the muscular activities subside. Regarding the Sensations of Organic Life, commentary is almost superfluous. With some not unimportant excep- tions, organic pains are connected with the loss of power in some vital function, and organic pleasures with the opposite. Wounds, hurts, diseases, suffocation, thirst, hunger, nausea, are so many assaults upon our vitality. ENERGETIC OUTBURST FROM ACUTE PAIN. 305 Taken in the gross, there can be no dispute as to their general tendency. As to the exceptions, the study of them,, in some instances, at least, serves to elucidate the principle. Cold is a painful agent ; yet we know that it increases the functional activity of the muscles, the nerves, the lungs, and the digestion — depressing only one organ, the skin. We may, hence, infer that the skin is an organ of greater sensibility than any of these others. The stimulation is sometimes obtained without the depression, — as in the immediate reaction after a cold bath, w^hereby the skin recovers its tone ; the whole effect is then exhilarating. Another apparent exception is the occasional absence of all pain in the sick bed ; also, the happy elation sometimes shown in the last moments of life. These cases prove, what we are already prepared for, by the example of muscular repose already cited, that a high condition of all the vital functions is not necessary to agreeable sensibility ; and open up the important inquiry — Which of these functions are most connected with our happiness, and which least ? It is clear that great muscular energy, exerted or possessed, is not an immediate essential, although an indirect adjunct of considerable value. It would seem equally clear that the power of digestion, and a certain degree of animal heat, are indispensable. There are states of inanition, of indigestion, and of chillness, that would sink the loftiest spirit into de- spair. Thus it may be, that the comfort of the bed-ridden patient, and the placidity of the dying moments, are in a measure due to the fact, that disease has overtaken chiefly the functions that least participa,te in our sensitive life. Painless extinction is in this way contrasted with suffering continued through a long life. There are parts whose derangement is not felt till on the eve of a fatal issue ; there are others that cannot be impaired without making the fact known, and that may work ill for many years before causing death. Even the organs most connected with mind, next to the brain, may undergo morbid changes that do not prevent them from giving their usual genial 20 306 THE INSTINCTIVE PLAY OF FEELING. response to a pleasurable wave. Obstructed bowels will quench more happiness than certain kinds of organic dis- ease of the intestines. The lungs are sometimes at the last stage of decay before affecting the enjoyment of the patient ; while the healthiest man is distressed by partial •■suffocation. AVhen we pass from the Organic Feelings to the Sensa- tions of the live senses, we miss the same decided coincid- ences. In Taste and Smell, for example, the rule might hold with those sensations that involve important vital -organs as the Stomach and the Lungs, but scarcely with the proper sensibilities of the senses. A taste merely sweet, without being a relish, gives pleasure ; but we cannot, in this instance, assign any marked increase of vital function. A bitter taste can even operate as a tonic. So with odours. We have sweet odours that are sickly, in other words, de- pressing ; and although some of the malodours may lower the vital power, this does not always happen, and there is no proportion between the pain and the low^ering of the functions. Soft and agreeable touches have an effect on the mind somewhat analogous to agreeable warmth ; but we cannot attribute the same physical consequences to the one as to the other. On the other hand, the painful smart, far' from diminishing the energies, rather excites them, for a time at least ; so that, here too, the induction would appear to fail. The pleasures of Hearing and Sight are possibly accom- panied with increased vital energy to some extent. When a person is brought from confinement in the dark to the light of day, there is observed a rise in the pulsation and in the breathing ; which is so far in favour of the general doctrine. Still, we cannot contend, that the degree of augmented vital energy corresponds always with the degree ■of the pleasure. In short, the principle that served us so well in summing up most of the organic pleasures and pains, does not apparently hold in the five senses. Some addi- tional modes of action must be sought for, in order to give a complete theory of pleasure and pain. PLEASURE AND PAIN IN THEIR MANIFESTATIONS. 307 19. So much for the known agents of pleasure and pain. We now proceed to study the manifestations. This will enlarge the scope of reference in quoting examples of the opposing modes. We are all familiar with the ordinary displays of muscu- lar movement expressive of various states of feeling. There is a very great degree of uniformity in the ways that human beings show the presence of pleasure and pain, as well as emotions not necessaril}' falling under either. We know, in particular, how the features of the face respond to every passing shade of feeling having a certain pitch of intensity. The influence of human beings on each other, in the way of arousing and imparting emotional moods, as well as the interpretation of states of feeling, is greatly due to these uniforin or constant manifestations. The art productions of all ages have recognized the meaning and the value of these indications for awakening human interest. The scien- tific analysis is only recent, and has gone but very little way to render an account, in the form of rational explanation, of the essential circumstances in our familiar experience. For the purposes of this inquiry, expression may be divided as above into Effects of Movement and Organic Effects. Under Movement, we have more especially the expression of the face, on which the greatest obscurity still hangs ; and next the movements of the body at large. The Voice is also a specialized organ for giving play to the feelings of the moment. Expression of the Face. — The expression of the face has been completely analyzed by Sir Charles Bell. In pleasing emotions, the eyebrows are raised and the mouth dilated, the whole effect being to open up the countenance. In pain- ful emotions, the corrugator of the eyebrow acts according to its name ; the mouth is drawn together, and perhaps depressed at the angles, by the operation of the proper muscles. The selection of these particular muscles, which is remarkably uniform in the race, still remains an enigma. Of facial expression, as of voice, it is remarked that the 308 THE INSTINCTIVE PLAY OF FEELING. muscular organs are small in themselves, and allied to centres possessed of considerable force. Hence the inten- sity of the manifestation, and the readiness to appear under very slight stimuli. Expression of the Voice. — All animals that have the power of vocal expression make it a medium of emotional outburst. Its variations are not so numerous in the lower animals, and, consequently, similar tones are used for very different states of mind. At the same time, as we rise in the scale, we find the number of expressive modes steadily increasing, until they enable us to discern, not merely the broad differences of pleasure and pain, but the degrees of intensity of those, and also the distinctive emotions of anger, love, and fear. In the human subject, the instinctive notes of passion are of considerable number, being further aug- mented by imitation and culture. The organs for emitting sound in man and in animals are small in bulk, but well supplied by nerves and nerve centres. In the diffused stimulus of states of feeling of average or more than average intensity, vocal outbursts are unfailing. Long before the voice is specifically developed for particular modes of feeling, it partakes of the indiscriminate wave of emotion, brought on through the primitive constitution of the brain. We cannot cany our hypothesis of the cerebral constitution beyond this assumption of a free relationship between central energy and muscular excitement generally. Movements of the Body at Large. — The whole body responds to the successive waves of feeling when they reach a certain point of intensity. The character of these various move- ments, although more vague and undecided than the fea- tures and the voice, is still sufficiently various and specific to help the indications of the prevailing modes of feeling. The broad difference betw^een pleasure and pain never fails to be apparent ; being supported by the great fundamental distinction between the two as respects the energy of the manifestations. Involuntary Muscles. — The waves of strong feeling, affect- GENERAL LAW OF EMOTIONAL EXPRESSION. 309 ing first the features and the voice, and next the voluntary muscles, end by influencing tlie lungs, the heart, the ali- mentary canal, and the fibres of the arteries generally. There is less of discrimination in the appearances made by these organs ; but the difference under pleasure and under pain is sufficiently apparent. The spasmodic outbursts of Laughter and Grief find their instrumentality in the involuntary movements. Organic Effects. — The secreting glands already enumerated respond characteristically to differences of feeling, and are, in addition, expressive indications of our various moods. These organs are acted on, principally, through the involun- tary muscles. It is as yet doubtful how far the nervous system can stimulate secretion or excretion by a direct and immediate effluence of nervous power. AVe are now prepared to follow up the illustration al- ready given of the law that connects states of pleasure with an increase, and states of pain with an abatement, of vital function. The mqst notable exception to this law is what frequently happens under sudden and acute pain. In that condition the violence of the movements may surpass in energy any of the ordinary movements attached to the pleasurable wave. Moreover, there may be states of greatest conscious pleasure with only the most trifling manifestations ; showing that, for pleasure, nervous, even more than muscular actuation, is essential. Sudden and acute pain is, in appearance, a stimulant of our activities at all points. But notwithstanding the vehemence of the display, the inference is delusive. Take the case of a man starting from a violent scald. The motor nerves of the system become all alive for the instant, and throw a violent current into the moving mem- bers, inspiring a temporary spasmodic energy. But look at the other side of the picture. In the first place, this spas- modic burst has drawn away the regular supply of nerve 310 THE INSTINCTIVE PLAT OF FEELING. force from the organic functions — all of which will be found to be seriously impaired on the occasion ; so that, at best, there is but a disturbance of the usually healthy direction of the vital power. Again, consider what happens at the end ; how frightful the prostration that follows this painful stimulation. We shall then be convinced that, on the whole, power has been profusely sacrificed, although, from the susceptibility of the nerves to an acute stimulus, there was for a time a manifestation of unusual energy. And we can only recover from the consequent depression and collapse by a course of nourishment and repose. ' In pain, the body is exerted to violent tension, and all the' emotions and passions allied to pain, or having their origin and foundation in painful sensations, have this general distinction of character, that there is an energetic action or tremor, the effect of universal and great excitement. It must at the same time be remembered, that all the passions of this class, some more im- mediately, others more indii'ectly, produce in the second stage of exhaustion, debility, and loss of tone from over-exertion ' (Anatomy of Expression, p. 154). As regards increase of vital power in states of pleasure, the erectness of the body, the raising and throwing back of the head, the gesticulation with the arms and the activity of the movements generally, in whatever exercise is sug- gested for the time, are the normal expression of a pleasur- able outburst. The smiling expression of the features, the stimulus to laughter, are also usual accompaniments. In the ordinary synonyms of the word pleasure, we find such epithets as lively, animated, gay, cheerful, hilarious, applied to the movements and expression — all tending to suggest that our energies are exalted for the time. In joyful moods, the features are dilated ; the voice is full and strong ; the gesticulation is abundant ; the verj^ thoughts are richer. In the gambols of the young, we see to advantage the coupling of the two facts — mental delight and bodily energy. ' Under a transport of Joy,' says Darwin, ' or of vivid EXPEESSION OF PLEASURE. 311 Pleasure, there is a strong tendency to various purposeless, movements, and to the utterance of various sounds. We see this in our young cliildren, in their loud laughter,, clapping of hands, and jumping for joy ; in the bounding- and barking of a dog when going to walk with his master ; and in the frisking of a horse when turned into an open field.- The contrast of painful expression, w^hen not disturbed by the violence of the acute and sudden forms of pain, is confirmatory and illustrative. The body is dejected into collapse, the voice feeble and characterized by a long-drawn wailing note, the features assume their painful attitude^ although modified and disguised by the convulsive accom- paniments of grief. In states of pain and depression, among the various symptoms there stand forth prominently the enfeeblement and collapse of the body and limbs, — just as erectness and energetic activity characterize the opposing condition. ' In sorrow,' says Bell, ' a general languor pervades the whole countenance. The violence and tension of grief, the lamentations and the tumult, like all strong excitements,, gradually exhaust the frame. Sadness and regret, wath de- pression of spirits and fond recollections, succeed ; and lassitude of the whole body, with dejection of the face and heaviness of the eyes, are the most striking characteristics. The lips are relaxed, and the lower jaw drops ; the upper eyelid falls and half covers the pupil of the eye. The eye is frequently filled with tears, and the eyebrows take an inclination similar to that which the depressors of the angles of the lips give to the mouth.' 20. The convulsive outbursts of laughter and sobbing or grief are, in every sense of the word, instinctive, and are thoroughly characteristic of opposing moods. The convulsive outburst in laughter is connected with the suddenness of the producing cause, and also its vehe- mence, — both leading to a surcharge of nervous excitement, for which some outlet is necessarv. The influence on re- 312 THE INSTINCTIVE PLAY OF FEELING. spiration is a regulating effect ; it controls the taking in of oxygen, and, thereby, the supply of arterial blood to the nerve centres. Violent emotion of every kind shows itself in muscular display, and finds some relief in that circumstance. But the respiratory organ is more especially instrumental as a check to too great activity. Without entering into the various causes of laughter, we may say that it is a joyful expression. The principal organ in the case is the Diaphragm; all else is subordinate and secondary. That large muscle, which is the chief agent in the act of inspiration, — its contraction increasing the capacity of the chest, — is convulsed in laughter : in other words, it is made to undergo a series of rapid and violent contractions. Some great accession of stimulus from the brain has reached it, and the consequence is, that the person 'draws a full breath, and throws it out in interrupted, short, and audible cachinnations '. Nervous power has been generated somewhere, and is here discharged into the great muscle of inspiration. The concurring or subsidiary actions also indicate an increase of power. When the laughter is audible, we know that the vocal chords have been made tense through a stimulus applied to the muscles of the larynx.* The convulsive outburst of ^He/ contrasts strikingly with the above. The principal agency in the effect is still the convul- sive action of the chest, but with a difference. The expiration, which in the other case was violently increased, is rendered sloiu. The diaphragm must answer for this fact, or rather the ner- vous centres that maintain it in operation. These centres, * " The Sound of Laughter is produced by a deep inspiration followed by short, interrupted, spasmodic contractions of the chest, and, especially, of the diaphragm. Hence, we hear of " laughter holding both his sides". From the shaking of the body, the head nods to and fro. The lower jaw often quivers up and down, — as is likewise the case with some species of baboons, when they are much pleased. During laughter, the mouth is opened more or less widely with the corners drawn much backwards, as well as a little upwards ; and the upper lip is somewhat raised. The drawing back of the comers is best seen in moderate laughter, and especially in a broad smile ' (Darwin, p. 202). SPASMODIC OUTBURSTS OF LAUGHTER AND GRIEF. 313 instead of overflowing, have become bankrupt ; they cannot even keep up the usual supply of power. This partial stop- page, or paralysis, of the diaphragm is a key to the whole phenomenon. To prevent suffocation, the muscles of inspira- tion have to be stimulated by efforts, like the application of bellows to inflate the lungs of a drowning man; which forces on, by reaction, an additional expiratory impulse. The great declension of vital energy is apparent. The accessories attest the same fact. The voice is feebly exerted, and the conse- quence is a long-drawn, melancholy note. The pharynx is convulsed, and is incapable of its rhythmical movements in swallowing. The features are relaxed, except in so far as they sympathize with the efforts of forced inspiration. These appearances are sometimes modified, as when a robust child bursts out in a violent fit of crying, expending a great deal of energy on the occasion. Great animal spirits can afford this manifestation ; and it may be little else than an outlet for surplus power, having less of sorrow than of anger. But that would not be the fair or t\T3ical instance. In all cases, the reaction shows that power has been wasted and the system impoverished, — the very opposite of laughter. The lachrymal effusion is an accompaniment of grief; but there are also tears of joy. In the extreme of merriment, the eye is moistened and suffused. We can easily suppose, that an increased vital stimulus of the lachrymal gland and sac would promote the secretion of the healthy liquid ; and that this, by coursing over the sensitive surface of the eyelids, would give a certain genial sensation, which we enjoy in the happy moods of tender emotion. The amount may be in- creased so as almost to reach the point of visible drops, and still be of the genial character. But we must not conclude that the profuse stream that overflows in the outburst of grief, is merely the same action carried one stage farther. The common fact of abundance of liquid does not prove that all else is the same. As we may have a profuse salivation, containing very little of the material that avails for insali- vating the food, so w^e may have a profuse lachrymal effusion. 314 THE INSTINCTIVE PLAY OF FEELING. caused, not by the increased, but by the diminished, action of the gland, — -in which case- the quahty would be radically changed. I make this assumption, partly on speculative grounds, and partly because I think any one will recognize a difference in the sensation of the eyelids, when moistened under a joyful wave, and when the moistening comes of pain or depression. Not only in painful states, but also in extreme in- stances of pleasurable emotion, the blood-vessels of the brain are congested, and the effusion of tears is one mode of relief. 21. The principle now contended for, not only explains a large and important region of facts, but is essential to the preservation of the individual. If pleasure were something subversive of vital force, our system would be a house divided against itself. On the other hand, if the above principle were rigorously true, we should never be inwardly moved to act in a manner prejudicial to our physical welfare. That we are so moved is, then, a proof of the existence of some modifying influences, which must be brought to light, in order to a complete theory of pleasure and pain. It has been seen that the ordinary pleasures of the five senses do not point to any great or marked increase of vitality ; and one might say the same of many of the special emotions — wonder, affection, power, knowledge, fine art, etc. That these are accompanied by some increase of vital power is proved by their expres- sion, — which is of a lively, animated kind, whenever the pleasure is considerable. Yet it could not be said, that the increase of vigour in the system at large corresponds on all occasions to the degree of the pleasure. A still more startling exception is presented by the Narcotic stimulants ; for these are known to debihtate and waste- the powers of life. And if it be maintained that this is only an after consequence, and corresponds to the stage when the mental tone has changed to pain and depression, I reply that such is not the fact: a man drinking to intoxication loses his physical energy long before the feeling of exhilaration abates ; and the pleasurable PLEASURE DUE TO STIMULATION AS SUCH. 315 excitement of tobacco and of opium may continue under an almost total prostration of the vital forces. We are thus called upon to qualify the doctrine that connects Pleasure and Self-conservation, by at least one other doctrine connecting Pleasure with Stimulation as such. The precise limits of this second principle are to be deter- mined by an examination of the facts. 22. It is convenient to divide the modes of stimulation into two classes :— first, what may be called the natural stimulants of the Senses and the Emotions ; and secondly. Narcotics and Drugs. First. On examining the natural stimulants of the Senses, what we appear to find is this. Touches, sounds, sights, are pleasurable within certain liinits of intensity (excepting, per- haps, discordant sounds). Pain in these three higher senses usually arises from excess in the stimulus applied. The point of excess is exceedingly variable in different persons, and, in the same person, at different times ; and notoriously depends upon the vigour of the system. So that we may say with certainty, as regards the sensations of Touch, Hearing, and Sight, that sensation, as such, is pleasurable within limits determined by the vigour of the nervous system. As regards the chemical senses, Taste and Smell, we cannot lay down the rule in the same positive manner ; we cannot affirm the difference between painful tastes or odours and those that are pleasant to be merely a difference of acuteness. We do not at present understand what are the distinctive modes of action of sweet and bitter tastes on the nervous substance ; and we may not say, regarding tastes and odours, that sensation, as such, is pleasurable. At all events, these pleasures and pains are not obviously explained on the principle of Conservation : both the one and the other are referable to some form of Stimulation. A bad odour does not owe its painful agency to depression of vitality, nor a sweet odour to the opposite fact. Some of the simpler emotions can be easily explained on one or other of the two principles. Wonder is a pleasurable 316 THE INSTINCTIVE PLAY OF FEELING. stimulant, if not applied out of proportion to the vigour of the system. So with tender feeling, with the sentiment of power, fine art, etc. Many of the painful emotions are asso- ciated with depressing agencies : fear, sorrow, shame, are familiar examples. These may, also, operate as perverting stimulants, or irritants, of the nervous system. And now, in the second place, as regards narcotic stimu- lation, we have a series of substances — alcohol, tobacco, tea, opium, haschish (Indian hemp), betel-nut — that are pleasur- able, but hardly in any degree favouring vital action. We may allow them some influence in promoting the physical vigour for a brief interval of time; but their effect, as stimu- lants of the mental tone, is out of all proportion to the most that can be claimed for them in that respect. On the other side, if carried beyond certain narrow bounds, they under- mine and destroy the human constitution ; and the motive of self-conservation is not always able to avert that conse- quence. The law of Stimulation, as a supplementary principle to Conservation, amounts to this : — We possess a certain amount of nervous vigour or irritability, which is converted into the full actuality of pleasure, only when impelled by shocks that have no nutritive tendency, but merely draw upon, and con- sume, the accumulated power. If we apply stimulants, up to a certain point, we do not dissipate force beyond what will be repaired ; if we fall short of that point, we miss the pleasure that our frame is able to sustain ; if we exceed the point, we run into a declension or a degeneracy. It would seem that we can afford both the natural stimula- tion of the senses, and a certain small amount of stimula- ting drugs, and yet not overdraw our allowance of nervous power. 23. One might, not without plausibility, maintain the position that Stimulation is the main cause of pleasure, and that the nourishment of vital energy merely enables this to be pushed to greater lengths, without degenerating into pain. The facts would, undoubtedly, bear such interpretation. It CONSERVATION CONTRASTED WITH STIMULATION. 317 could be said that stimulation of some kind can never be absent ; and that, by increasing the vital power, this stimu- lation, falling on the refreshed nervous substance, would impart the pleasurable tone. But it is better, in the present state of our knowledge, not to push either principle to exclu- sive predominance. A certain physical vitality, in some organs at least, if not an essential condition of a pleasurable tone, can always enhance the effect of the other cause, and in practice is often all that we need to look to. The contrast of country and city life familiarly illustrates the two principles. The pleasure of the one results mainly from the conservative and healthy or vitalizing influences ; the pleasure of the other from variety of stimulation. It is possible to attain a measure of happiness in either situation. High health is not an essential of pleasure ; the nerves may respond to agreeable stimulations in the midst of some (not all) modes of bodily weakness. The readiness to take on the thrill of intense pleasure is a speciality of the nervous constitution. The state of the general system, and more par- ticularly of the glandular organs, is an important element ; but the main foundation in the case is to be sought in an endowment of the nerve tissue. A man may have, as it were, a natural genius for being happy. (For a further discussion of the physical accompaniments of Feeling, see Appendix B.) THE INSTINCTIVE GERMS OF VOLITION. 24. In a former chapter, I endeavoured to establish, as an important fact of the human S3'stem, that our various organs are liable to be moved by a stimulus proceeding from the nervous centres, in the absence of any impres- sions from without, or any antecedent state of feeling what- soever. This fact of spontaneous activity, I look upon as an essential prelude to voluntary power, making indeed one of the terms or elements of Volition : in other words, Volition is a compound, made up of this and something else. Neither the existence of spontaneous actions, nor the 318 THE INSTINCTIVE GERMS OF VOLITION. essential connexion of these with voluntary actions, has been, so far as I am aware, advanced as a doctrine by any writer on the human mind ; but the following interesting extracts from the great physiologist, Miiller, will show that he has been forcibly impressed with both the one and the other of these views. ' It is evident that the ultimate source of voluntary motion cannot depend on any conscious conception of its object ; for voluntary [I should say ' spontaneous,'] motions are performed by the foetus before any object can occur to the mind, before an idea can possibly be conceived of what the voluntary motion effects ; we must therefore view the question in a much simpler manner. On what do the first voluntary movements in the foetus depend? All the complex conditions which give rise to voluntary motions, in the adult, are here absent. Its own body is the sole world from which the obscure conceptions of the foetus that excite its actions can be derived. The foetus moves its limbs at first, not for the attainment of any object, but solely because if can move them. Since, however, on this supposition, there can be no particular reason for the movement of any one part, and the foetus would have equal cause to move all its muscles at the same time, there must be something which de- termines this or that voluntary motion to be performed, — which incites the retraction, first of this foot or arm, and then of the other.' This last supposition, as to the equal tendency of all the muscles to come into action through the spontaneous activity of the centres, is, I think, too absolutely stated. There can hardly exist such a perfectly balanced charge of the centres, as to make all of them equally ready to commence a stimulus of the muscles under their control, like the ass of Buridan between the two bundles of hay. It will always happen that some one will be more prone to act than another, from the mere state of constitutional or nutritive vigour belonging to it ; and, when that one has exhausted itself, the discharge of some other may be expected. Then, as regards the tendency to move the limbs by turns, we have already seen that this alternation is provided for by a distinct arrangement ; so SPONTANEITY ACCORDING TO MULLER. 319 that, when by any means a motion of the legs is commenced, that motion is guided in a regular alternation. I continue the quotation from Miiller. ' The knowledge of the changes of position, which are pro- duced by given movements, is gained gradually, and only by means of the movements themselves ; the first play of the will on single groups of the radicle motor fibres of the nerves in the medulla oblongata, must therefore be independent of any aim towards change of position ; it is a mere play of volition, without any conception of the effects thereby produced in the limbs. This voluntary [say, rather, spontaneous] excitation of the origins of the nervous fibres, without objects in view, gives rise to motions, changes of posture, and consequent sensations. Thus a connexion, is established i?i the yet void mind hetween certain >iensations and cer- tain motions. When subsequently a sensation is excited from without, in any one part of the body, the mind will be already aware that the voluntary motion, which is in consequence exe- cuted, will manifest itself in the limb which was the seat of sen- sation ; the foetus in utero will move the limb that is pressed upon, and not all the limbs simultaneously. The voluntary movements of animals must be developed in the same manner. The bird which begins to sing, is necessitated by an instinct to incite the nerves of its laryngeal muscles to action .; tones are thus produced. By the repetition of this blind exertion of voli- tion, the bird at length learns to connect the kind of cause with the character of the effect produced. ' We have already learned, from many other facts, that the nervous principle in the medulla oblongata is in a state of extra- ordinary tension, or proneness to action ; that the slightest change in its condition excites a discharge of nervous intiuence, as manifested in laughing, sneezing, sobbing, etc. While the tension of the nervous principle is not disturbed, we are equally ready to excite voluntary movements in any part of the body, and such is the state of rest or inaction. Every mental impulse to motions disturbs the balance of this tension, and causes a dis- charge of nervous influence in a determinate direction, — that is, excites to action a certain number of the fibres of the nervous motor apparatus ' {Physiology, pp. 936-7). 320 THE INSTINCTIVE GERMS OF VOLITION. This last view I conceive to be an accurate statement of the nature of nervous energy. The nervous system may be compared to an organ with bellows constantly charged, and ready to be let off in any direction, according to the particular keys that are touched. The stimulus of our sensations and feelings, instead of supplying the inward power, merely has its chief efficacy in determining the manner and place of the discharge. The centres of speech and song, for example, when fresh and healthy, either overflow so as to commence action in a purely spontaneous way, or they remain undis- charged till irritated by some external influence, — as, for example, the sound of another voice. The bird whose morning song has lain dormant for a time, breaks forth at the stimulus of another songster just begun. 25. We must now, therefore, specifically consider what there is in volition over and above the spontaneous discharge of active impulses upon our various moving organs, — limbs, body, voice, tongue, eyes, etc. If we look at this kind of impulse closely, we shall see wherein its defect or insuffi- ciency lies, — namely, in the random nature of it. Being dependent on the condition of the various nervous centres, the discharge is regulated by physical circumstances, and not by the ends, purposes, or uses of the animal. When the centres of locomotion are fresh and exuberant, as in the dog unchained of a morning, the animal sets off at the top of his speed ; the force once exhausted, the creature comes to a stand-still in the same spontaneous way, like a watch rmi down. But this moment of exhausted spontaneity is the very moment when an animal ought properly to be active in procuring food and replenishment to the system ; and there ought to be in the state of exhaustion itself a stimulus to act — just as a watch run down would require, in order to be self- sustaining, to pull some string that would set going a power to wind it up, — or as a dying fire ought to act on a spring for putting on fresh coals. Mere spontaneity, there- fore, stops far short of what our volition does for us in the way of self-preservation: a power that dies out, when action MERE SPONTANEITY INSUFFICIENT. 321 is most needed, cannot be the appropriate support of our existence. Miiller's application of the term ' vohmtary ' to the initial movements prompted solely by the state of tension of the nerve centres, is not strictly correct. These movements are but one term of the couple that makes up an act of volition ; both a feelino- and a movement are necessary parts of every such act. A morsel of food on the tongue stimulates the move- ments of mastication : this is a voluntary effort, an effort prompted and controlled by a feeling, — namely, the sensation of taste or relish. Acts performed without any stimulus of feeling are usually described as involuntary : such are the spasms of disease, and many of the reflex movements. 26. The subject of Will, in its full development, con- stitutes an integral branch of the systematic handling of the mind. It is introduced at this stage by way of completing the survey of the primordial elements of our mental framework, in contradistinction to the acquired. Our acquisitions presuppose an instinctive foundation ; and clearness requires that we should first state and define the fundamental portion before tracing in detail the process of upbuilding. Moreover, this is the best opportunity for strongly marking the contrast between true voluntary activity and modes of action already recounted that are not voluntary. It is usual, in speaking of Will, to characterize it by the peculiarity of Choice. The supposition is that, where we do not make a choice between two alternative courses, we do not put forth an exercise of Will. That this is a common case — indeed, a very common case — in the nature Will, is quite certain ; but the question still arises whether this is absolutely the first germ or commence- ment of Will. Is it . not possible to perform an act of Will upon one single object of desire, — as when a thirsty man swallows a draught of water ? Another moot point involved in the foregoing, is, — whether we can will without first forming an idea or an image of the object willed. A similar objection may be taken here ; the contention being 21 322 THE INSTINCTIVE GERMS OF VOLITION. that this is not the primary form of will, but a secondary develop- ment. The point, therefore, is to state what we conceive to be the absolutely earliest phase of voluntary action, and to give reasons for such statement. Two things have to be included in this primordial estimate, the one casting light upon the other, — viz., the earliest traceable germ of Will, and the most highly generalized form of the power. The first presupposes the second, in the order of inquiry ; when the second is once settled, the first is partly settled also. Hence, it seems desirable to commence with the attempt to reach the most general type of the act of willing. We assume that neither the act of choosing between alternative courses, nor the precognition of an object willed, can be taken as the earliest assignable position of the mind in willing. 27. Ill arriving at the most highly g,eiieralized definition of Will, we should carefully keep apart the mental and the physical, — a matter of some difficulty, seeing that the executive of the Will so often shows itself in muscular movements — that is, in putting the active organs in motion. Still, there is a proper mode of observing the separation ; and in doing so, in the present case, priority is most properly given to the mental fact. The Will then is shown in the presence of some pleasure or pain, followed by an activity — in the one case, to retain, husband, or increase the pleasure, and, in the other, to subdue or diminish the pain. In short, Will is made up of an antecedent motive, resolvable into pleasure or pain, and a consequent movement or series of movements ; the movements having reference to the one great end of contributing to our enjoyment. This may be taken provisionally as the most generally received statement of the law of the Will, but subject to modifying conditions and complications, which, however, may be reserved until the analysis of the general situation is completed. The antecedent fact, or motive, is an urgency involved in our pleasurable and painful conditions to do something. What that something is to be, and how it is to be discovered, is the history of our voluntary power, and is a vast process THE NATURE OF MOTIVE. 323 of acquirement, — in fact, a leading department of our life education. At the earlier stages of our being, we have many pains operating as motives, without any established connexion between the specific pain and its remedial move- ment, even supposing such movement were at our command if we only knew it. The first ^Doint in the history, then, is— How do we pass from the state of blankness in the connexion of motive and act, to the state of completed connexion, which renders the motives efficient as well as urgent? To recount this at length, is to supply the full development of the Will, — which is not now intended. All that belongs to the present task is to state the primitive, initial, or instinctive circumstance that renders it possible. So far as appears, this primitive datum is as follows : — Given a coincidence of a pain with a movement that consciously alleviates it, or of a pleasure with a movement that consciously increases it, such move- ment will be maintained or increased so long as it has the peculiar effect described. This, at least, is a presupposition not to be dispensed with. It is, moreover, the last psychical foundation or generalized link of voluntary action : we seem incapable of resolving it into anything more general. With- out such a link, in whatever terms we may state it, no progress in volmitary acquisition is conceivable. This primordial situation being assumed, it has to be implemented by a means of bringing about the requisite coincidences between motive and movement. Here it is that our voluntary education has to commence its upward course in difficulties and struggles ; which difficulties have to be surmounted by a method that, in the first instance, must be pronounced random or fortuitous. Such is the second leading assumption at the foundation of the Will. The source of this fortuitous commencement that is to lead up to the requisite happy coincidences is variously stated. In the present work, the principal stress is laid upon Spontaneity, as growing out of the natural overflow of activity in the healthy subject. Eeasons are given to show that this is the form of 324 THE INSTINCTIVE GEEMS OF VOLITION. movement best adapted to the purpose. The principal alternative mode is the mobility growing out of emotional diffusion, on which Dr. James Ward places exclusive reliance; Mr. Darwin inclining to the same view, but rather implicitly than explicitly. If there are spontaneous tendencies to movement in the muscular organs at large, they must be of regular and stated occurrence ; the in- vigoration of the muscles and muscular centres is a periodic and a recurrent fact, while the emotional outburst is occasional and uncertain. Moreover, the emotional grouping is less easy to dissever than the chance movements of spontaneity ; and hence the greater difficulty of securing the concurrence of the appro- priate action by itself. A third, and final, postulate is the confirmation of a coincidence once hit upon, through the plastic force of in- telligence, otherwise described as Retentiveness or Memory. Witliout this, the lucky coincidences w^ould be barren or unproductive. The conditions of hastening the operation are conditions belonging to the known working of the great upbuilding energy of our constitution. The effect is, occasionally, so decisive that one single coincidence forges a link between the two concurring states that is adequate for all future time. 28. By the law of concomitance of Mind and Body, these stages in the growth of the Will, which have been stated as purely subjective facts, have a definite physical foundation, in which physical laws have their full play. In our earliest consciousness of voluntary efforts, what we are aware of is a power to instigate trials in a random way (the appropriate linking being still a blank), on the chance of arriving at the suitable coincidence. This is an advanced stage in the growth of Will ; yet we can scarcely conceive to ourselves the previous stages. There are occasions when we have a pain to relieve, and do not consciously enter upon trials ; while, if a fortunate coin- cidence were to occur, we clench the coincidence, and make a step accordingly. We have arrived at the stage of trial and error, but may refrain from consciously acting upon it — BEGINNINGS OF EARLIEST PROMPTINGS HYPOTHETICAL. 325 a mere chance omission, accounted for by want of urgency. It would take a revelation of early evolutionary processes to indicate our mode of arriving at this familiar stage, which must be, after all, speculative and hypothetical. We lay down the law of acting out a coincidence, as an absolutely primitive or primordial endowment, because we find it in operation all through life (and in the lower annnals as well), and through all variety of circumstances ; we being unable to dispense with its help in our most mature accomphsh- ments of voluntary control.* Our voluntary education notoriously proceeds upon the method of using each finished acquirement to build up others ; thus giving greater compass and efficiency to our trial-and-error capability. No additional principle enters into the case. It is the law of acquisition in every depart- ment. 29. It IS illustrative of the foregoing positions to cite in a pointed manner the Contrasts of Will. These contrasts are specific modes under the one genus of Active Movements of the muscular organs. The movements of the involuntary muscles may be set aside, in the first instance, as too far removed from the proper voluntary type, although analogous to a certain extent. The illustrative contrasts, therefore, may commence with the * The law of immediate connexion of a present movement with a present feeling, without any intervening link, is seen in operation all through life, notwithstanding the occurrence of intermediate linkings. It is of the very essence of trial-and-error, in which the check of an unfavourable movement, aiid the maintenance of a favourable, are instantaneous and sure. Turning a corner and encountering a chilling wind, we are urged to stop or retreat by a tendency that needs no deliberation, and no interposition of an idea or conception of the act. It is shown in the course of our voluntary education how this primordial impetus is the essential antecedent of all other forms of voluntary agency. Our familiar daily experience in the way of restlessness, or shifting of attitude, indicates the will in its initial form. The slightest uneasiness that a change of position can remedy usually instigates such a change, even although consciousness is engrossed with other things. It certainly could not be said that the removal of a fly from the forehead involves the elaborate routine of choice and full conception of the act to be performed. 326 THE INSTINCTIVE GEKMS OF VOLITION. Instincts, whose end is the conservation of the system, and their instrument the voluntary muscles. The point of con- trast here is the possession of the powers at birth ; education, experience, and conscious struggle being dispensed with. As a second contrast, we may cite the Spontaneous move- ments in their earliest aspect, while as yet unassociated with definite uses. Although we put forward these as a con- stituent element in the growth of the will, we do not call them voluntary until they have gone through the process of linking themselves with our feelings and wants. The Emotional movements are properly contrasted with the Voluntary, although the contrast is often difficult to set out. AVhat are usually termed movements of expression are really a mixture of emotional and voluntary ; the pure or typical examples of emotion being few in number, and not easy to detect and isolate. In this complication lies the great subtlety of the question as to the absolute priority, in our mental history, of emotion or volition. There are un- doubted cases where an emotional wave carries with it movements whose origin may be attributed to the urgency of a painful state which they alleviate ; such are the sounds of the voice that bring companions to assist in distress. There is not an equal reason for attributing the same origin to such pure outbursts of pleasure as in laughter and the various movements of ecstatic joy. The shiverings of cold, the tremblings of fear, the sudden flow of tears, the collapse of pain generally, would seem to be purely organic consequences of the nervous state accompanying the feelings themselves. On the other hand, a volitional origin may be attributed to the stare of surprise, the flight from danger, the gestures of the irascible outburst, the tones and outward shows of affec- tion, the upturned gaze of reverence. A very large number of the attitudes expressive of passion that are employed in art are volitional only in their present bearing, and not in their earlier origin. Note on Pleasure as a Voluntary Motive. — In considering the motives to the will as constituted by Pleasure and Pain, we find the least ambiguous PLEASURE AS A VOLUNTARY MOTIVE. 327 aiid miqiiestionable to be Pain. So much is this the case, that plausible attempts are made to reduce under Pain the entire motive urgency- of our Volition ; the seeming -influence of Pleasm-e as a motive being explained away by a reference to a supposed indirect agency of pain. The imiversality of the motive efficacy of pain is most manifest. The exceptions are of a kind to leave the rule substantially intact. One notable exception is the case where we console ourselves by an emotional outbm'st, which disposes of the pain by simply abrogating it. Another exception is the exhausted state of our active powers, which no longer respond to the prompting, or, if they do, leave us in a still worse condition of suffering. Indeed, there are always possible counter motives to restrain the natural workings of our painful moments. A higher volition ma^' intervene to suppress the motive power of an actual pain, while the mere fact of such intervention serves to confirm .the genuineness of its motive force. That pleasure seeking its own continuance or its increase is a voluntary motive, we find abundantly exemplified. The Appetites contam this situation, along with the urgency to remove pain. The state called desire involves alike the diminution of pain and the attainment of positive pleasure. A common form of human weakness is the pursuit of pleasure beyond all reasonable limit, not to speak of incurring pain as well. The coimter aspect of the urgency of pleasure in these instances is a certain apparent tendency in pleasiu-able states to arrest or bring to a stand-still our voluntary promptings. There is a class of pleasures that may be described as satisfying and serene, disposing us to remam where we are, rather than enter on the piu'suit of something still higher. These cases, however, are not conclusive, if they are meant to prove that pleasure in general impedes, instead of furthering, the voluntary promptings. For one thing, we may be well aware that to push our present enjoyment to a still higher pitch is to run upon the bristhng point of some pain, which pain would be the genuine motive to qiiiescence. This is the pru- dential or precautionary safeguard against excesses in the love of pleasure. It would leave intact the position that pleasure as such urges us to seek it in still greater amounts. Even quiescent pleasure is vohuitary, so far as the continuance of it is concerned ; mere dm-ation may count to the consciousness as a motive, no less than intensity or degree. To keep what we have would follow as an effect of deprivation, — which is really a mode of pain. The point then would be : — In what circumstances may pleasure so completely soothe the voluntary cravings, that we remain in perfect quiescence and contentment, there being no rocks ahead in aiming at its augmentation, and no danger of its falhng away under inaction ? If it 328 THE INSTINCTIVE GERMS OF VOLITION. be urged that onr active powers may be at such a low ebb that further attainments would cost too much effort, we should simply be brought round again to one of the forms of pain as a motive. Perhaps, the nearest approach to the quieting influence of pure pleasure is the case where we find ourselves at a pitch of unusual enjoy- ment, — something far beyond our habitual experience, something that we rarely encounter, and cannot readily imagine to, be increased. The out-going of the will in such cases would rather be for the resumption or the recurrence of the state, and not for increasing its intensity. It is not uncommon to set aside both pain and pleasure as motives to the will, and to substitute the state of Desire, — which has the merit of covering the whole of the ground. This, however, is an imsatisfactory solution. Desire is not a primitive fact, but a result of antecedents that can be stated apart from voluntary urgency. These antecedents must still consist of either pleasure or pain, or else that peculiar form of incitement to action known as the Fixed Idea. It is, no doubt, the insufficiency of the name Pain to cover the whole range of our motives, especially the cases where pursuit of pleasure is the conspicuous fact, that has led to the adoption of the wider term, notwithstanding that it expresses more than either pleasure or pain alone. We want some general phrase that would equally apply to pleasurable and to painful situations, —something that would indicate a sense of insufficiency, or dissatisfaction, and would apply equally to the removal of pain proper and to the attainment of iileasure. , So far, the theory of voluntary action has been conducted on the purely psychical aspect. Every suggestion of physical cause and eifect has been carefully left out of account : the physical instrumentality in our corporeal acts does not constitute an essential link in the sequence of motive and result. It is, indeed, possible and not unusual to refer the subjective sequence to a line of physical cause and effect, and to show a certain consistency between the physical and the mental sequences. The law that a movement bringing pain tends to be arrested, and a movement bringing pleasure to be promoted, is with some plausibility referred to a general principle of nervous action, whereby, seeing that pleasure is in so many cases associated with increase, and pain with diminu- tion, of vital energy, there would grow out of this circumstance a dis- position of pleasure to feed, and of pain to sap, its own producing energy. There is an undoubted consistency between the two sides of our being in this hypothesis. If the opposite were the fact throughout our whole framework, it is quite apparent that we PHYSICAL RENDERING OF THE VOLUNTARY SEQUENCE. 329 should be urged into suicidal courses. If the hypothesis itself were fully, strictly, literally realized in everything that we did, our self-protection and the resources of self-preservation would be far beyond what we actually experience. It has been abundantly seen, under the induction of pleasure and pain, that we have pleasures whose nervous accompaniments are in favour of healthy action, while not a few others are the reverse. So far, the law of pleasure and pain, viewed simply in the aspect of feeling, has its anomalies repeated in the law of the will, — that is, in the tendency of pleasure to nourish, and of pain to deplete, our active energy. The hypothesis in question demands for its adequacy a far- reaching, although not incredible or impossible, assumption, — viz., that the tendency of pleasure, through the medium of its physical accompaniments, to heighten for the moment the active energies of the framework in general, somehow finds a way to concentrate upon the specific movement adapted to the precise case. This is a very large demand in itself, and would seem to naedagreat number of chance experiments before the lucky coincidence is reached. The hypothesis is by no means impossible ; but its truth or falsehood has no place in the subjective theory of the will, as established upon an induction of subjective facts. Its natural place is under the hypothesis of Evolution, where it is an important, if not indis- pensable, item. It is so far a useful hypothesis in assisting expo- sition of the subjective theory of will ; but that theory stands upon its own evidence, and is nowise dependent upon such a hypothesis. THE HIGHER INSTINCTS. 80. The subject of Instinct has its widest range and greatest subtlety in connexion with our intellectual powers. While by far the largest part of our intelligence is a matter of acquisition, conducted under our own observation, there is, in point of fact, an instinctive or primordial start which ought to be more or less easily assigned. In some im- portant departments of self-preservation, there are primitive powers, not merely of feeling and of will, but of truly in- telligent guidance, such as, in other cases, comes to us by experience solely. 330 THE HIGHER INSTINCTS. The inquiries into infant development, which have en- deavoured to assign precise dates as well as the order of sequence of the childish powers, have for their end to find out, if possible, what is absolutely primitive in our intellectual endowments. The problem is necessarily com- plicated, if only by the circumstance that a certain time is needed for the actual manifestation of capabilities that must be possessed at birth. The knowledge of our intellectual powers is properly gained, in the first instance, by our observation of the workings of intellect subsequent to the stage of infancy. We can see before our eyes the history of successive acquisitions, from commencement to consummation. On this experience, we base our formulae of the intellectual powers ; and we make use of it to read backwards into the earlier stages, checking this retrospective reading by actual observations of properly childish manifestations. One of the most prominent facts of our intelligence is our gift of reading and interpreting the manifested expres- sion of those about us. The central fact of this power, in its highest refinement, is shown in regard to the features of the human face. The delicacy of our perception of the minutest fluctuations of facial attitudes and movements, and our facility in their emotional rendering, whether in- stinctive or acquired, or both, constitute a vast portion of our mental accomplishments.* It not merely teaches us what are the passing moods of our fellows, but is a great moral or emotional influence : it wakens our sympathies * The extraordinary hold that human expression has taken of our inmost sense faculty is proved by the influence of the merest scratches of resem- blance ; the line of a mouth, the outline of an eye, without even the full face. This is a tremendous fact of itself ; and to analyze its implications is to dissolve deep-seated forces of association beyond what even a life of ex- perience could give. The interest in animals very unlike ourselves, the personation of brute matter and chance forms and outlines, is unique and overpowering. So with outward appearances generally ; the extreme, perhaps, being the expression of death, — which probably no education could eradicate to the pitch of making us see in a corpse lifeless matter. INSTINCTIVE READING OF EMOTIONAL EXPRESSION. 331 and our antipathies — arousing in ourselves a certain amount of the feehng that is manifested. A certain rationale of the development of this power, in the course of experience, may be readily assigned. It may be said that we can associate good offices from others, in the way of substantial gratifications, with the aspect of features and demeanour wherewith these are accompanied. The process is perfectly natural and familiar ; yet, the precocity, the maturity, the firmness of the linking thus established would seem to be out of all proportion to the opportunities afforded. In such circumstances, it is proper to put the question, — Has Instinct any part in the result ? The most decided criterion in the case is the earliest date when the infant is distinctively susceptible to the broad difference between the smiling, the frowning, and the dis- tressed expression of a familiar face. Among the multiplied observations of infant development, this specific point is seldom adverted to. The following experience, given by Darwin in the history of his own child, is notable and suggestive : — * With respect to the feeling of sympathy, this was clearly shown at six months and eleven days by his melancholy face, with the corners of his mouth well depressed, when his nurse pretended to cry ' (Mind, 1st Series, vol. ii. p. 289). Considering that the so-called power of sympathy rests upon a correct interpretation already possessed of the manifestations of painful feeling, the state of advancement of the infant's perception of manifested emotional workings is decisively put in evidence. The age assigned totally excludes the reference to experience as the genesis of the power. We must descend to the depths of primordial endowment for any adequate explanation of the fact. No doubt, it belongs to the researches bearing upon infant development to ascertain what share of this great accomplishment may fairly be attributed to instinct, — that is, heredity. Without speculating further on what must be a laborious determination of a matter of fact, which has as yet gone but 332 THE HIGHEE INSTINCTS. a little way, we cannot help taking notice of one very im- portant implication, not confined to this special department, — namely the instinctive rendering of tri-dimensional space. This is a problem of intellectual instinct, standing apart and alone, and yet the groundwork of many others. Our feeling ourselves at home in the extended world, from the date of our earliest recollections, implies a vast intellectual endowment, however it be accounted for. That much of it is engrained in us at birth is proved in a variety of ways ; the intelligent reading of expression being not the most decisive. In regard to it, the salient circumstance is the inadequacy of our education during the first three years to lead us up to what our consciousness can attest as our power of conceiving the external world at that date. More decisive, because less ambiguous, are the instincts of the lower animals, — as, for example, their power of intelligent guidance within a few hours or days of birth. The bird that can measure its aim at a grain of corn as soon as it leaves the egg, and the quadruped that can find itself at home in a day or two after being dropped, possess by implication nearly all that is involved in the perception of extended magnitude or space. In man, the known acquisitions connected with the outer framework of things bear a very large proportion to what can possibly be assigned to him at birth ; yet, this last share is something of very considerable, although not easily definable, amount. In the lower animals, the dispro- portion is not so remarkable : when we descend below the mammals, the instinct of space and its belongings claims a near approach to the superinduced acquirements. It belongs to a later stage of the exposition — when what is attainable at present in our knowledge of the intellectual processes, as gathered from our life experience, is made use of — to survey our various primary notions among which Space naturally takes a lead. The foregoing remarks are intended as forming a bridge of transition between the two departments of Instinct and Intelligence (see note F). THE INTELLECT WE now proceed to view the Intellect, or the thinking function of the mind. The various faculties known as Memory, Judgment, Abstraction, Eeason, Imagination, — are modes or varieties of Intellect. Although we cannot be said ever to exert this portion of our mental system in total separation from the other elements of mind — Feeling and Volition, — yet scientific method requires it to be de- scribed apart. The primary, or fundamental attributes of Thought, or Intelligence, have been already stated to be, — Consciousness of Difference, Consciousness of Agreement, and Retentiveness. The exposition of the Intellect will consist in tracing out the workings of these several attributes ; the previous book containing the enumeration of all that we have to discriminate, identify, and retain. (1) The most fundamental property is disceimination or Consciousness of Difference. To be distinctively affected by two or more successive impressions may be considered the primary fact of consciousness. This fact, however, does not stand alone in our developed experience. Changes of impression produce at once phenomena of difference and of agreement. But, although occurring together, the two modes can always be kept separate, and their intellectual consequences run far apart ; the one, discrimination, pointing to the individual, the other, agreement, pointing to the general. In our handling of the feelings of movement and the sensations, the classified enumeration in detail took for granted the consciousness of difference as the groundwork of the whole. In other words, the intellectual property of 336 THE INTELLECT. discrimination was tacitly assumed in advance, as necessary for the exposition of the department of Sensation proper. In fact, the manifestation of the quahty as regards our primary states has been pushed almost to exhaustion ; leaving no proper sphere for illustration under Intellect proper. Delicacy of discrimination varies greatly in different senses and in different classes of sensations, and thus marks out the higher and lower intellectual quaUty of each, or the fitness to enter into intellectual trains and combinations. There still remains the region of accjiiired discriminations, the result of the retentive power of the mind ; being, so to speak, educated differences, — as in the processes of chemical testing, the diagnosis of disease, and the decisions of legal interpretation. There is no separate law of the intellect at work in these cases, beyond what belongs to the powers of acquisition and the employment of our acquired products as applied to practice. The consciousness of Agreement is the natural comple- ment of discrimination in the progress of our knowledge. The two together exhaust the ultimate definition of know- ledge. Agreement, in the form of Similarity in Diversity, is one grand reproductive forc6 of the human intellect, subject to assignable conditions of the highest import, on which account it occupies a large division of the treatment of the Intellectual Powers. In point of arrangement, however, it is preceded by the discussion of the third of the great fundamental properties, — viz., Betentiveness. (2) Eetentiveness, then, is the name for the most generalised aspect of our powers of memory, habit, or acquisition, and may be described under two modes or gradations. First. The continuance or persistence of conscious impressions, after the withdrawal of the agent or cause. When the ear is struck by a sonorous wave, there follows the sensation of sound ; but the cessation of the cause does not mean the cessation of the mental excitement : there is a certain continuation of the feeling, although usually much ULTIMATE PROCESSES OF INTELLECT. 337 feebler in degree, while the same in kind. Thus it is that our mental states due to external causes outlast the causes themselves, and constitute for us a life in memory, over- and above the life in actuality. A far higher mode of retentiveness remains. After the impression of a sound has entirely vanished, the mind being occupied with a number of other things, there is a possibility of recovering from temporary oblivion the mental effect, or idea, without repeating the actual sound. AVe bring back to mind, or remember, sights, and sounds, and feelings, and thoughts, that may not have been in actual consciousness for long periods of time. This higher mode of retentiveness supposes that something has been ingrained in the mental and nervous structure ; that an effect has been produced such that any number of succeeding impressions have not been able to efface. Now, one circumstance or condition of restoring any one of these former states of consciousness, is the presence of something that had more or less frequently been in company -with that state. Thus, w'e are reminded of a name — as star, tree, house — by seeing the thing ; the pre- vious concurrence of name and thing has brought about a mental adhesion between the two. So pervasive is this condition in the workings of the Retentive, or Plastic, pro- perty of the mind, that we take it along with the designation Association hy Contiguity, and carry out the exemplification accordingly. (3) The consciousness of Agreement will have next to be viewed as a mode of mental reproduction totally dis- tinct from the foregoing. After experiencing a certain im- pression, and passing from it to something else, the recur rence produces a certain shock of consciousness — the shock of recognition ; which is of various degrees according to assignable circumstances. The transition from one im- pression to a second gives the consciousness of difference or discrimination ; the occurrence of likeness in the midst of change yields a new and distinct effect, the effect of agreement. AVhen we see in the child the features of the 22 338 THE INTELLECT. man, we are struck by agreement in the midst of differ- ence. Thus, then, the power of recognition, identification, or discovery of hkeness in unhkeness, is a further means of bringing to consciousness past ideas ; and is spoken of as the Associating, or Reproductive, principle of Similarity. AVe are as often reminded of things by their resemblance to something present, as by their previous proxitnity to what is now in the view. Contiguity and Similarity express two great principles, or forces, of mental reproduction; they are distinct powers of the mind, varjdng in degree among in- dividuals — the one sometimes preponderating, and some- times the other. The first governs Acquisition, the second Invention. The commonly recognized intellectual faculties will be found to resolve themselves into the three primitive opera- tions of intellect now specified. The faculty called Memorij is founded chiefly in the Ketentive Power, or contiguity, with a certain aid from Similarity. The processes of Reason and Abstraction are in the main due to Similarity ; there being in both the identifpng of resemblances under more or less of difference. What is termed Judgment may consist in Discrimination, on the one hand, or in the Sense of Agreement, on the other : we judge two or more things either to differ or to agree. It is impossible to find any case of Judging that does not, in the last resort, mean one or other of these two essential activities of the intellect. Lastly, Imagination is a product of all the three fundamentals of our intelligence, with the addition of an element of Emo- tion. The exposition of Intellect proper will consist mainly in a full development of the two processes of Eetentiveness and Agreement. These will constitute the two first chapters. A third chapter will be devoted to the cases of Complicated mental Reproduction, including the association by Contrast. A fourth will deal with the employment of the intellectual forces to form new constructions — the Creative or Inventive faculty of the mind. "USES OF THE ANALYSIS OF THE IXTELLECT. 839 The purposes to be served by a scientific discussion of our Intellectual powers are these : — 1. The explanation of the Laws that regulate the stream and Succession of our Thoughts is calculated to gratify an enlightened curiosity, or the natural desire of knowing the causes of things. Every person alive to the pleasures of knowledge is led, by this prompting, to inquire into the laws that simplify the great complications of the world. And there is no department where this desire is more likely to arise than in the ever present workings of the mind itself. 2. The theory of the intellectual powers affords a means of representing and explaining the differences of Intellectual Character in human beings. Such differences must refer to one or other of the fundamental attributes of our intelh- gence, and be susceptible of classification accordingly. 3. The art of Education must be grounded upon an accurate knowledge of the attribute of Eetentiveness. We are concerned to find out the circumstances that favour, and those that thwart, the process of mental acquisition. What Locke termed the ' Conduct of the Understand- ing,' meanjng the economical and effective employment of all our intellectual forces, includes education, and some things besides. It implies the methods of directing and aiding us in the higher operations, as Reasoning and Inven- tion. The presumption is that a knowledge of the tools that we work with, may assist us in using them to the best advantage. 4. The theory of what constitutes Knowledge, what are the limits of human knowledge, and what is the nature of legitimate Explanation, must needs grow out of the investi- gation of our intellectual powers. It was to ascertain exactly what man is competent to know, that Locke applied himself to the inquiries that are the subject of his Essay, — the publication of which was an epoch in the science of mind. 5. There are certain questions of vital interest, whose solution turns on ascertaining what parts of our knowledge 340 THE INTELLECT. are primitive, and what acquired. It is a recognized portion of the science of mind to trace to their earhest origin our ideas of Sx^ace, Time, Cause, and many other general notions of commanding importance. Scarcely any department of Intellect tries more severely our acquaintance with the laws that govern the progress and succession of our thoughts. CHAPTEE I. EETEXTIVENESS— LAW OF CONTIGUITY. 1. rpHIS principle is the basis of Memory, Habit, and the J- Acquired Powers in general. Writers on Mental Science have described it under various names. Sir William Hamilton terms it the law of ' Kediutegration ' ; regarding it as the principle whereby one part of a whole brings up the other parts, as when the first words of a quotation recall the remainder, or one house in a street suggests the succeeding ones. The associating links called Order in Time, Order in Place, and Cause and Effect, are all included under it. We might also name it the law of Association proper, of Adhe- sion, Mental Adhesiveness, or Acquisition. The following is a general statement of this mode of mental reproduction. Actions, Sensations, and States of Feeling, occurring together or in close succession, tend to grow together or cohere, in such a way that, when any one of them is afterwards presented to the mind, the others are apt to be brought up in idea. There are various circumstances or conditions that regu- late and modify the operation of this principle, so as to render the adhesive growth more or less rapid and secure. These will be best brought out by degrees in the course of the exposition. As a general rule, Eepetition is necessary in order to render coherent in the mind a train or aggregate of images — as, for example, the successive aspects of a panorama — with a suffi- cient degree of force to make one suggest the others at an after period. The precise degree of repetition needed de- pends on a variety of causes, the quality of the individual mind being an important element. 342 EETENTIVENESS — LAW OF CONTIGUITY. Eetentiveness is exemplified throughout the present chapter under the aspect expressed by Contiguity of two or more im- pressions. In point of fact, the hnking process so thoroughly pervades our acts of memory that we regard it as the typical form of the retentive operation. It will be necessary at the proper place to recognize cases where an impression deemed single is confirmed, deepened, or made self-sustaining, as a con- sequence of repetition. The same plastic operation of the brain must be regarded to be at work here also ; and the same con- ditions will regulate the pace of the acquirement. In point of fact, while we are acquiring mental unions of coupled impressions — as names and things, sequences of movements, objects and feelings or other groupings, — -we are, at the same time, strengthening or confirming our mental hold of the separate members of the united groups. Hence, everything that is involved in the Eetentive operation, every condition of its working, is completely exhausted in the full illustration of the Law" of Contiguity. In opening the discussion of the Intellectual Powers with a statement and systematic development of the retentive function of the mind, we assume a balance of convenience as against several alternative courses. In treating of the sensations, it was necessary to presuppose the working of the intellectual processes strictly so called, the Eetentive process being one. An alternative still remains, — viz., to defer the treatment of the laws of intellect still further, in order to deal with some important products that follow close upon sensation, and so far explicable with only a tacit assumption of these intellectual laws. The name ' Perception, ' or the Perccjjt, designates a large class of such products ; and their detailed handling is an important chapter of the mind, at whatever point it may be most con- veniently introduced. This operation is essentially a mode of Mental Aggregation, and depends upon the retentive or adhesive force, as bodied forth under the Law" of Contiguity. It stands intermediate between Sensation proper and the still higher intellectual product of Memory or Ideation properly so called. A further question of arrangement arises. Can the perception products be conveniently located among the developments of the Law of Contiguity without interrupting the exposition of that MOVEMENTS. 343 law in its most characteristic workings? For all practical purposes, the consideration of Contiguity is mainly resolvable into the conditions and facilities of mental acquisition, or education, in which it is the potent factor. Doubtless, there are many questions of its operation where the mere fact of Aggrega- tion, and the sequence of successive steps, are more taken account of than the rapidity or economy of the adhesive growth. It is for such cases that the bare statement of the law may answer all purposes, the full elucidation being postponed. At the same time, nothing would appear to be lost by commencing at once with the specific illustration of the principle ; while, on the other hand, we do only but justice to its enormous sweep in the evolution of the intellect at large (see Note G). MOVEMENTS. 2. I shall commence the detailed exposition of the Law of Contiguity with the case of Muscular Activity ; including under this head all kinds of movements, attitudes, and efforts of resistance. Through the intellectual property of adhesiveness or plasticity, as expressed by this principle of contiguous asso- ciation, movements can be linked together in trains, and made to succeed each other, with the same certainty and invariable sequence that we find in the instinctive successions of rhythmical action, already discussed. The complicated evolutiotis of a dance come to flow of their own accord, no less than the movements on all fours of the newly-dropped lamb. We may begin with remarking the operation of the adhesive principle upon the Spontaneous and Instinctive actions themselves. These actions are plainly confirmed and invigorated by repetition. Although many creatures can walk as soon as they are born, they walk much better after a little practice. Here, however, we cannot easily make allow^ance for the growth of the parts themselves, apart from the effect of exercise. The muscles of the limbs increase in size, and the nerve centres that stimulate and sustain the rhythmical movements acquire more develop- 344 RETENTIVENESS — LAW OF CONTIGUITY. ment, through time alone. By practice,— that is, by repetition, — the infant sacks with more ease and vigour. In learning to walk, exercise undoubtedly concurs with the primitive alternating tendency of the limbs. The muscles of the body are strengthened by growth ; this growth is accelerated, if they are regularly exercised within limits ; and the very same is likely to be true of the nerves and nerve centres that dictate the flow and alternation of muscular move- ments. I have endeavoured to establish, as a fact, the spontaneous commencement of all the actions that we term voluntary. The limbs, the features, the eyes, the voice, the tongue, the jaw, the head, the trunk, etc., begin to move inconsequence of an unprompted flow of stimulus from the nerve centres. This flow will be sometimes to one set of members, and sometimes to another ; so that the organs may act separately and independently under the influence thus imparted. Now, such spontaneous movements are, without doubt, confirmed by repetition, and are thereby made to recur more readily in the future. Any movement struck out by central energy leaves, it may be supposed, a trace behind : a less amount of nervous impulse will be required for its renewal. By a spontaneous stimulus, the hands are closed ; the act of closing determines a current or bent in that direction, and the next exertion is so much the easier. By one prompting, the arms are raised and lowered alternately ; by another, they are moved forwards and backwards ; in the course of a few repetitions, adhesiveness comes in aid of the in- ward stimulus, and the movements grow more frequent and more decided. Through the spontaneous action of the centres, the eyes a,re moved to and fro, and iteration gives facility to the exercise. So, the voice is moved variously by an impulse from within ; and each movement and note is made easier for thenext occasion when the centres discharge their energy by that channel. The tongue is an organ with many movements, and all voluntary : these commence of their own accord, and are strengthened and, as it were, AGGREGATION OF MOVEMENTS. 345 developed by repetition. The inclinations and sweep of the head, and of the trunk generally, are of the same class. The iteration of all these various movements does not make them voluntary movements, in the proper sense of the expression ; but it prepares them for becoming such by a future and distinct acquisition. It makes them recur more frequently and more readily, enhancing the spontaneous impulse of the centres. On some one occasion, the voice sounds a high note. As to the first stimulus of the vocal energy, we can say nothing further than that, with all the active organs, there is associated a nervous battery for com- mencing their movements. After an interval, the same high note is struck by a like discharge from the proper centre. AVhen several repetitions have occurred in this way, a facility is gained ; either a less tension of the centre will originate the note, or it will be better sustained when it comes. Thus it is that a variety of detached movements are getting themselves prepared for subsequent use. To persons that have not reflected on the very great difficulty and labour attending the growth of voluntary movements in infancy, this hypothesis of spontaneity so much dwelt upon, will seem uncalled for and unlikely. But I shall have to show, at a later stage, how impossible it is, without a supposition of this kind, to account for the com- mencement of the will. 8. "We pass, next, to the acquisition of Aggregates and Trains of Movements as exemplified in mechanical opera- tions generally. I assume the case of an individual already able to command the limbs, or other parts, as directed by another person, or by an example set for imitation. Aggrefjation or Agglutination. — This is well exemplified in the acquirement of walking. A certain portion of the requisite adjustments — viz., that growing out of the alter- nation of the limbs — is pure instinct, although in the human subject demanding the confirmation of exercise or practice. With this instinctive portion has to be associated all the trunk and other movements necessary for preserving the 346 EETENTIVENESS — LAW OF CONTIGUITY. balance, wliicli do not seem to be instinctively given. In each situation of the body and limbs during the act of walk- ing, a number of muscular adjustments concur in perfect fusion, so as to dispense with every trace of voluntary attention, which is the test of perfect acquisition. In all kinds of manual education, agglutinated or con- curring movements are involved along with the trains in sequence. In firing a musket, the attitude of the body, arms, and head is highly complex, and yet surely determined by a single act of volition ; while, in the progress of the acquire- ment, it was necessary to bring the different adjustments into play by a volition for each. Such is the regular course of our active education, and such the criterion of its complete- ness. The attitudes and gestures that constitute the expression of our feelings are highly complex, both as concurring aggregates, and as trains or successions. A certain extent of grouping for this end is given by nature, and its formation goes far back in the history of sentient beings. The educa- tion that we go through by way of adding refinement to nature's original, is so much added to the primitive agglu- tination ; and the expression of an emotion by a graceful or finished actor is still richer in concurring motor impulses. The process of education and the criterion of its complete- ness can be described in the terms already given for manual accomplishments. The acquiring of articulate Speech extensively involves the same agglutination. Every letter stands in need of an adjustment of tongue, jaws, and lips, difficult at first, but, at last, so easy that we do not know that we are performing a complicated act. Trains, Successions, or Concatenations. — These may be exemplified by the sequence of acts in eating, — necessarily one of our earliest acquirements. The lifting of the morsel by the spoon or fork, the carry- ing of it to the mouth, the opening of the mouth at the right moment, the action of the jaws and tongue, — all TRAINS OF MOVEMENTS. 347 exhibit a succession of regulated acts, fixed into mechanical coherence and certainty by the mere fact that they have been made to succeed each other a great number of times. The accidental biting of the tongue exemplifies a failure or interruption of the coherent working of the organs. The action of carrying the hand to the mouth is followed by the opening of the jaws, as surely as the two alternate acts concerned in breathing give birth to each other. In most mechanical successions, the feeling of the effect produced at each stage is a link in the transition to the next. Thus, in writing, the sight of the part last formed is the preamble to what comes next, as much so as the motion executed ; in which case, the sequence is not Bne of pure motions — one motion bringing on the next in the habitual order. This mixture of sensations and motions in complex trains will form a separate head : I am desirous, at the pre- sent stage, to select a few examples of actual or pure move- ments linked together, without any other element being present. As, however, the guidance by feeling is neces- sary in the course of learning any mechanical effort, the fixing of movements in a train, independently of such guidance, is the last stage, or highest perfection of mechanical acquirement. Thus, when one is playing on a pianoforte, and attending to something else at the same time, the sequence may be said to consist of pure movements : that is to say, each stroke is associated with another definite stroke or touch, through the whole succession of the piece. Yet, even in this case, it is difficult to say how much there is of a kind of latent sensation in the fingers and the ear, acting along with the association of pure movements. A deaf person speaking must depend almost entirely on the associated sequence of movements ; the only other assistance is the muscular feelings themselves, which always count for something. In saying over, to one's self, words committed by rote, the sequence of articulate motions is perfect. One word uttered brings on the next, independently of either hearing or the consciousness of articulation. This 348 EETENTIVENESS — LAW OF CONTIGUITY. is a proof of the very great aptitude for associated move- ment belonging to the vocal organs ; hardly any other part .of the body, not even the hands, can acquire such perfection of unconscious dexterity. In knitting, there is probably the same sequence of movements, acquired after thousands of repetitions. The simpler figures of dancing can be gone through, with this mechanical and unconscious certainty, after a great amount of practice ; but the docility of the lower limbs is far inferior to the hands, while these are second to the voice. The difficulty of forming a perfect association of mere movements, and the dependence of most of the mechanical trains upon Ihe sense of the effect produced, are curiously illustrated in paralyzed sensibility. Thus, there is an often- quoted case of a woman that could not hold a baby in her arms except by keeping her eyes fixed upon it. She had no sense of weight in her arms, and the sustained tension of the muscles was not sufficiently associated with the taking up of the child, by the muscular link alone. The sight of the eye was able to supply the want of arm sensibility, while both could not be dispensed with. A more familiar example of the same fact is the signing of one's name — an operation that, by repetition, has been brought up to the highest pitch of automatic or mechanical sequence ; and yet, when we make our signature without seeing it, the execution is verj- faulty. It is the linking together of movements so perfectly as to make them succeed one another without consciousness, that brings the acquisitions into comparison with the in- stincts. Such actions are sometimes called secondary- automatic. Although very few of the cases of mechanical acquire- ment in general can belong to the class we are now consider- ing, there are important distinctions of human character, founded on the facility of acquiring trains of movement, so as to uphold them with the least possible help from the guiding sensations and ideas. The trains of action so CONDITIONS OF RETENTIVENESS. 349 acquired cost the smallest amount of mental fatigue in the performance ; they may, moreover, go on while the mind is employed upon other things. 4. In regard to the conditions that regulate the pace of our various acquisitions, some are general, others are special to individual kinds. The general conditions are these : — I. A certain amount of Continuance, or Repetition of the matter to be learned, is requisite ; and the greater the continuance, or the more frequent the repetition, the greater the progress of the learner. Deficiency in the other con- ditions has to be made up by a protracted iteration. II. The Concentration of the mind is an important con- dition. This means, physically, that the forces of the nervous system are strongly engaged upon the particular act, — which is possible onW by keeping the attention from wandering to other things. It is well known that distraction of mind is a bar to acquirement. The element of mental Concentration admits of various modes of wording ; and it is desirable to fix the phenomenon itself apart from any one exclusive mode. The name Con- sciousness, as signifying mental life and activity in the widest sense, needs to be tied down to one particular application, in order to serve the purpose in view. The word ' Atten- tion ' is by some preferred as the leading term to denote what is meant ; a wider meaning than its ordinary accepta- tion being assigned to it. What is wanted in the case is to indicate (1) a certain degree of mental excitement or con- sciousness, and (2) the directing of this upon one intellectual act, to the exclusion of others. The process is easily under- stood in connexion with any of the senses. AVith a wide prospect before us, the eye can select one point so as to throw the whole of the visual energy upon that one point ; while the intensity of gaze may be such that the other portions of the scene, although actually inscribed on the retina, are all but unconscious. This is Concentration in its most typical and generally understood form. There 350 EETENTIVENESS — LAW OF CONTIGUITY. maybe a greater or less degree of excitement on the whole; but the point is that the entire benefit should be given to a narrow and select portion of the field of view. Under all the applications of the term Concentration, these two circumstances, — viz., amount of excitement and special direction, — are what make up its meaning. When the different sources or causes of mental ex- citement are reviewed, we find a very great difference, not merely in respect to the amount produced, but also in the element of special direction towards a given subject. We may contract a considerable intensity of consciousness, with no direction at all, or with a direction away from what we more particularly wish. Herein lies the character- istic distinctions of pleasure and pain as motives to the requisite concentration. The name Activity is especially adduced in reference to concentration or attention of mind, while Passivity is connected with the absence of that degree of consciousness that would be called attention or concentration. Yet, Passivity is not necessarily unconscious : it is merely a low degree of conscious excitement, in which no great impression is made by things that are actually presented to the view. In moving along a road, we cannot help receiving sensible impressions ; but the tone or tension of the mind may be so faint or feeble that these do not stamp themselves on the memory. In point of fact, there is a scale of degree from the zero of conscious impression to the highest possible pitch of excitement, or intellectual activity. In strictness, attention, activity, concentration, all point to one and the same circumstance. All are equally applicable to designating it, seeing that all are indifferently emplo5^ed for the end in view. The area of attention is said to be a varpng quantity, while the intensity is necessarily less as the area is greater. There is, however, a qualification to be given in this case, inasmuch as the purpose of embracing a large area may be to obtain a comprehensive view of some grand whole, MOTIVES TO CONCENTRATION. 351 which is as intently perceived as a smaller or more minute point taken in finer detail. Properly speaking, attention or concentration is the employment of the Will in the sphere of the Intellect. It is the stimulating adjunct that renders the intellectual processes effective for their purpose ; and, being itself de- pendent upon the feelings, it illustrates the necessity for the united action of all the forces of the mind in the sphere of intellectual production. The greatest of all motives to concentration is a present enjoyment of the work in hand. Any exercise possessing a special charm detains us by immediate attraction ; every- thing else is neglected, so long as the fascination lasts. This is the inherent power of the will in its immediate and most efficient manifestation — a present pleasure furthering a present action. It explains the great influence of what is called the Taste for a special pursuit. The taste or fascination for music, for science, for business, — ^keeps the mind of the learner exclusively bent upon the subject ; and the pace of acquisition is proportionally rapid. Next to present enjoyment, is associated or future enjoy- ment ; as when we devote ourselves to something unin- teresting or painful in itself, but calculated to bring future gratification. This is, generally speaking, a less urgent stimulation, as being the influence of pleasure existing only in idea. There may, however, be all degrees of intensity of the motive, according to the strength of the ideal represen- tation of the pleasure to come. It is on this stimulation that we go through the dry studies necessary to a lucrative profession or a favourite object of pursuit. The young are insufliciently actuated by prospective pleasure, owing to their inferior ideal hold of it ; and are, therefore, not power- fully moved in this way. A third form of concentration is when present pain is made use of to deter and withdraw the mind from causes of distraction, or matters having an intrinsically superior charm. This is the final resort in securing the attention of the 352 EETENTIVENESS — LAW OF CONTIGUITY. volatile learner. It is an inferior motive, on the score of economy, but cannot be dispensed with in early training. By an artificial appliance, the subject m hand is made com- 'parcUively the least unattractive. So with the use of future pains ; the same allowance being made for the difference in their character, as for pleasures existing only in prospect. The influence of Neutral Excitement may also be taken into account, as being a power of concentration provided it can be properly directed. This happens when the subject of consideration or attention is itself the origin of the excitement. Anything that strikes us with surprise, irrespective of either pleasure or pain, will receive the benefit of the excitement produced in the form of effective concentration. The least productive of all the kinds of conscious intensity is mere vague excitement, from whatever cause. In the absence of direction upon anything in particular, it is pure waste as far as concerns intellectual results. The case is still worse if it should turn out to be unhealthy or morbid excitement, in which no permanent linkings of thought can be fused. It is to be noted that the area of concentration is apt to be somewhat larger than the stimulating impression ; we cannot always keep the vision or the hearing to the exact spot where the influence is located. Hence, our memory of some interesting scene or event often involves collaterals in close proximity with the exciting cause. The mind, being raised to a high pitch of intense consciousness, will seize hold of whatever crosses the view at the particular moment ; and matters irrelevant to the main stimulus will obtain a share of the resulting cohesive force of retention. This fact is of sufficient importance to constitute a subsidiary law of the adhesive property. It is not uncommon, in stating the general conditions of Ee- tentiveness, or memory, to specify the vividness or intensity of an impression : thus, we readily remember such effects as an in- tense odour, a speech uttered with vehemence, a conflagration. This, however, resolves itself into the concentration of mental and nervous force, due to the emotional excitement. Apart from the GENERAL POWER OF RETEXTIVENESS. 353 feelings, an idea may be more or less distinct and clear, but is not properly more or less intense. If an inscription is legible with ease, it is everything that the intellect demands ; the adventi- tious aid of glaring characters, as when, at a public illumination, a sentiment is written in gas jets, is a species of excitement, se- curing an inoriinabt! amount of attention or concentration of mind. If we compare an object sharply defined with another whose lineaments are faded and obscure, there is a wide difference in the hold that the two would severally take on the memoiy ; but such impressions differ in kind, and not simply in degree. The names ' vivid ' and ' intense ' are scarcely applicable except by a figure. Without a decisive difference or contrast, the mind is not impressed at all ; everything that favours the contrast favours discrimination, and also depth of impression. All this, however, is presupposed as a fact or property of the Discnminating function of intellect, and is not to be repeated as appertaining to the Re- tentjce function. III. There appears to be, specific to each individual, a cer- tain degree of General Retentiveness, or a certain aptitude for acquirement generally. We find a great inequality in the progress of learners placed almost exactly in the same circumstances. Sometimes the difference refers only to single departments, as mechanical art, music, or language : it is then referable to special and local endovv^ments, as muscular sensibility, the musical ear, and so forth. Often, however, the superiority of individuals is seen in acquire- ment as a whole, in which form it is better regarded as a General power of Eetentiveness. 5. We shall advert, as we proceed, to the modif}dng cir- cumstances of a local kind peculiar to each class of acquisi- tions. As respects the present class. Movements, the special conditions seem to be as follows : — (1) Bodily Strength, or mere muscular vigour, must be regarded as favouring acquisition. Not only is it an indi- cation of a large share of vitality in the muscles, which is likely to attend their acquired aptitudes ; it also qualifies for enduring, without fatigue, a great amount of continuance or practice of the operations required. 23 ^54 RETENTIVENESS— LAW OF CONTIGUITY. (2) Distinct from mere muscular power is Spontaneity, or the active temperament ; meaning the natural proneness to copious muscular activity. This must be regarded as a property, not of the muscular tissue, but of the nerve centres on the active side of the brain. Hence, there is a likelihood, if not a certainty, that the endowment is accompanied with a greater facility in the association of movements. Observa- tion accords with the view. It is usually men of abounding natural activity that make adroit mechanics, good sports- men, and able combatants. (3) Of still greater importance is Muscular Delicacy, or Discrimination, — which is not necessarily involved in either of the foregoing heads, although more allied to the second. The power of discriminating nice shades of muscular move- ment is at the foundation of muscular expertness in every mode. We have abundant proof that, wherever delicacy of discrimination exists, there will be found a special retentive- ness of that class of impressions. The physical groundwork of the property is the abundance of the nerve elements — fibres and corpuscles ; out of which also must spring the capacity for varied groupings and fixed associations. Physical vigour m general, and those modes of it that are the counterparts of mental vigour in particular, must be reck- oned among the conditions of Eetentiveness. Other things being the same, acquisition is most rapid in health, and in the nourished and fresh condition of all the organs. "When the forces of the system run strongly to the nervous system generally, there is a natural exuberance of all the mental mani- festations ; and energy of mind is then compatible with much bodily feebleness, yet not with any circumstances that restrict the nourishment of the brain. IDEAL FEELINGS OF MOVEIMENT. 6. The continuance and revival of feelings of movement without movement itself — that is, ideal feelings, as opposed to the feelings accompanying actual movement — are a new and distinct case of the associating principle ; a case, too, THE SEAT OR EMBODIMENT OF IDEAS. 355 of great interest, as introducing us into the sphere of Thought. This transition from the external to the internal, from the Eeality to the Idea — the greatest leap that can be taken within the compass of our subject, — needs, in accordance with the principle of our whole exposition, to be prefaced by a consideration of the question: AVhat is the probable seat, or local embodiment, of a sensation, or a mechanical feeling, when persisting after the fact, or when revived with- out the reality '? The discussion of this question will in- terrupt, for a few pages, the exemplification of the law of Contiguous adhesiveness. 7. All the Muscular feelings can be sustained for some time after the phj^sical cause has ceased. All the sensations of the senses can be sustained in like manner, some more and some less easily ; and they can afterwards be revived as ideas by means of the associating forces. AVhat, then, is the mode of existence of those feelings, bereft of their outward support and first cause ? In what particular form do they possess or occupy the mental aud cerebral system ? This question admits of two different answers or assumptions, — one old and widely prevalent, the other new but better founded. The old notion supposes that the brain is a sort of receptacle of the impressions of sense, where they lie stored up in a chamber quite apart from the recipient apparatus, to be manifested again to the mind when the occasion calls. But the modern theory of the brain, already developed (see Introduction), suggests a totally different view. We have seen that the brain is only one part of the course of nervous action ; that the completed circles take in the nerves and the extremities of the body ; that nervous action supposes currents passing through these completed circles, or to and fro between the central ganglia and the organs of sense aud motion ; and that, short of a completed course, no nervous action exists. The idea of a cerebral closet shut off, is quite incompatible with the real manner of the working of nerve. Since, then, a sensation, in the 356 EETENTIVENESS — LAW OF CONTIGUITY. first instance, diffuses nerve currents through the interior of the brain outwards to the organs of expression and move- ment, — the persistence of that sensation, after the outward exciting cause is withdrawn, can be but a continuance of the same diffusive currents, perhaps less intense, but not otherwise different. The shock remaining in the ear and in the brain, after the sound of thunder, must pass through the same circles, and operate in the same way, as during the actual sound. We can have no reason for believing that, in this self-sustaining condition, the impression changes its seat, or passes into some new circles that have the special property of retaining it. Every part actuated after the shock must have been actuated hy the shock, only more powerfully. With this single difference of intensity, the mode of existence of a sensation persisting after the fact is essentially the same as its mode of existence during the fact : the same organs are occupied, the same current action goes on. We see in the continuance of the attitude and ex- pression the identical outward appearances, and these ap- pearances are produced by the course of power being still by the same routes. Moreover, the identity in the mode of consciousness implies that the manner of action within the brain is unaltered. 8. Now, if this be the case with impressions persisting when the cause has ceased, what view are we to adopt concerning impressions reproduced by mental causes alone, or without the aid of the original, as in ordinary recollec- tion ? What is the manner of occupation of the brain with a resuscitated feeling of resistance, a smell, or a sound? There is only one answer that seems admissible. The renev:ed feeling occupies the very same parts, and in the same manner, as the original feeling, and no other parts, nor in any other assignable manner. I believe that if our present knowledge of the brain had been present to the earliest speculators, this is the only hypothesis that would have occurred to them. For, where should a past feeling be re-embodied, if not in the same organs as the feeling when present ? It is only in this way EMBODIMENT OF MUSCULAR IDEAS. 357 that its identity can be preserved ; a feeling differently em- bodied would be a different feeling. It is possible, however, to adduce facts that set in a still clearer light this re-occupation of the sentient circles with recovered impressions and feelings. Take, first, the memory of feelings of energetic action, — as when reviving the exploits or exertions of yesterday. It is a notorious circumstance that, if there be much excitement attending the recollection of these, we can only with great difficulty prevent ourselves from getting up to repeat them. The rush of feeling has gone on the old tracks, and seizes the same muscles ; and would go the length of actually stimulating them to a repeti- tion. A child cannot describe anything that it was engaged in, without acting it out to the full length that the circum- stances will permit. A dog dreaming sets his feet going, and sometimes barks. The suppression of the full stage of perfect resuscitation needs an express effort of volition, and we are often even incapable of the effort. If the recollection were carried on in a separate chamber of the brain, it would not press in this way upon the bodily organs engaged in the actual transaction. The fact can only be, that the train of feeling is reinstated in the same parts as first vibrated to the original stimulus, and our recollection is merely a repeti- tion that does not usually go quite the same length, or stops short of actual execution. No better example could be fur- nished than the vocal recollections. When we recall the impression of a word or a sentence, if we do not speak it out, we feel the twitter of the organs just about to come to that point. The articulating parts — the larynx, the tongue, the lips — are all sensibly excited ; a suppressed ctrticulafAon is in fact the material of our recollection, the intellectual mani- festation, the idea of speech. Some persons of weak or in- continent nerves can hardly think without muttering — they talk to themselves. The excitement of the parts may be very slight — it may not go the length of perceptibly affecting the muscles ; but in the brain and communicating nerves it still passes the same rounds, however enfeebled in degree. 358 RBTENTTVENESS — LAW OF CONTIGUITY. The purposes of intellect can be served, even after this ex- treme enfeeblement of the currents, but their nature and their seat have not changed. They have not abandoned the walks of living articulation because they no longer speak out fully ; they have not taken refuge in new chambers of the brain. We feel at any moment how easy it is to convert the ideas into utterances ; it is only like making a whisper audible, — the mere addition of mechanical power. The ten- dency of the idea of an action to produce the fact, shows that the idea is already the fact in a weaker form. Thinking is restrained speaking or acting. If the disposition to yawn- ing exists, the idea, anywise brought up, will excite the action. The suppressive effort usually accompanying ideas of action, which renders them ideas and not movements, is too feeble in this case, and the idea is, therefore, a repetition to the full of the reality. 9. Although at present engaged in preparing the way for the association of muscular feelings, yet, as the doctrine in hand is general for all states of mind, I must add some parallel instances from passive sensation. Miiller has furnished several in point. He says : — ' The mere idea of a nauseous taste can excite the sensation even to the production of vomiting. The quality of the sensation is the property of ihe sensitive nerve, which is here excited without any ex- ternal agent. The mere sight of a person about to pass a sharp instrument over glass or porcelain is sufficient, as Darwin remarks, to excite the well-known sensation in the teeth. The mere thinking of objects capable, when present, of exciting shuddering, is sufficient to produce that sensation on the surface in persons of irritable habits. The special properties of the higher senses, sight and hearing, are rarely thus excited in the waking state, but very frequently in sleep and dreams ; for, that the images of dreams are really seen (under opium, images are actually seen), and not merely present in the imagination, any one may satisfy himself in his own person, by accustoming himself regularly to open his eyes when waking after a dream. The images seen in TENDENCY OF AN IDEA TO BECOME EEALITY. 359" the dream are then sometimes still visible, and can be ob- served to disappear gradually. This was remarked by Spinoza, and I have convinced myself of it in my own person' (p. 945). As another striking example, there may be adduced the fact that the sight of food brings about the flow of saliva in a hungry animal. The physiologist obtains saliva for experimental purposes, by presenting a savoury morsel to the view of a dog. The sight or thought of the infant induces the flow of milk in the mother. These, and other cases that might be quoted, clearly confirm what has been said, as to the return of the nervous currents, exactly on their own tracks, in revived sensation. We see that, when the revival is energetic, it goes the length of exciting even the surface of sense itself by a sort of back- movement. We might think of a blow on the hand, until the skin were actually irritated and inflamed. The attention very much directed to any part of the body, as the great toe, for instance, is apt to produce a distinct feeling in the part, — which we account for only by supposing a revived nerve current to flow there, making a sort of false sensation, — an influence from within mimicking the influences from without in sensation proper. This whole subject has been fully developed in the numerous experiments under the name of Hypnotism. Mr. Braid, of Manchester, was among the first to give it prominence. 10. The emotions and passions distinct from, but often accompanying sensations, are likewise similarly manifested in the reahty and m the idea. Anger takes exactly the same course in the system, whether with a person present, or with some one remembered or imagined. Nobody ever supposes in this case that the ideal passion is in any way difierent from the actual, or has any other course or seat in the brain. So with affection, egotism, fear, or any other sentiment or passion. In like manner, the remembrance of being angry, or puffed up, or terrified, will be a resuscita- tion of the identical state, and will actuate the same part, although the centrifugal wave may not be strong enough to 360 RETENTIVENBSS — LAW OF CONTIGUITY. agitate the surface as strongly as the original did. The recollection of the intenser feelings is necessarily weaker than the reality ; but, of some of the less agitating sensations and feelings manifested in action, the recollection may be quite equal to the reality. We can better afford the expen- diture necessary for reviving mild and gentle emotions. 11. The tendency of an idea to become the reality is a distinct source of active impulses in the mind. Our chief active faculty is expressed by A¥ill, or Volition, whose nature it is to urge us frora pain or to pleasure. But the disposition to proceed from a mere recollection, imagination, or idea, to the action that it represents, — not merely to think an act, but to do it, — is also a determining principle of human conduct, and often sets itself in opposition to the regular action of the will, as above defined. For the most part, the tendency is kept in check ; in ordinary circumstances, indeed, it does not manifest itself with any great energy, so that we may omit it from our reckoning of a man's motives. There are, however, circumstances that bring it forward as a considerable, and even preponderating, influ- ence in individual conduct. The extreme illustration is seen under the mesmeric sleep, which has this curious effect, among others, that the patient is open to the reception of ideas suggested by another person, while the senses and the naind are insusceptible to the external situation generally, and are, to that extent, asleep or unconscious. The wakeful- ness to our actual environment at each moment is necessarily the foremost circumstance in regulating our actions ; the influence of our ideas is usually subordinated to the influence of present realities. In sleep, the mind is dead to reality, and more or less awake to the current of ideas ; and in somnambulism and mesmeric sleep, and, to a less extent, in ordinary dreams, we act our ideas out to the full, the usual restraining power being dormant. In waking moments, the general rule is that ideas do not act themselves out ; their urgency is so small as to be in complete subjection to the will, operating under its ordinary FIXED IDEAS THWARTING THE WILL. 861 motives. But there are times when an idea possesses the mind so forcibly as to act itself out in opposition to the will, and, therefore, in opposition to those interests that the will should side with — the deliverance from pain and the further- ance of pleasure. This forcible possession is generally the consequence of great excitement accompanying an idea, or its taking a more than usual hold of the mind, whereby it does not pass away with the intellectual currents, but remains and predominates over every other thought pressing for admittance. l'2i. The domination of an idea is best seen in the work- ings of Fear. When any object causes fright, the idea of that object is stamped on the mind with an intensity corre- sponding to the degree of the fright. The actions of the individual are in conformity to this idea, and not to his proper volitions. A mother is in a state of panic regarding a supposed danger to her child : she is no longer capable of acting for the best ; the one exaggerated idea governs her whole conduct. The force that moves her is not volition ; it resides in the circles of mere intellect, inflamed into undue excitement on one idea. The healthy and regular action of the will, aiming at the suppression of pain and the procuring of pleasure, would work for subduing the state of panic, so as to leave the mind in a cool and collected condition, able to estimate the danger at its exact amount, and with refer- ence to all other interests. But the passion of fear is too much for the will. The idea rules the situation like a despot. The principle is also illustrated by the predominance of purely painful ideas, even although not causing fright. The mere fact that an idea is disagreeable would suggest to the will to banish it, and we often succeed in banishing the thought of an object that pains us ; but, sometimes, the intensity of the pain is such as to stamp it on the mind, and we cannot help acting it out, even to our own discomfort. Disgusts often exercise this unbidden ascendancy. The fascination of a precipice is a familiar and pertinent 362 EETENTIVENESS — LAW OF CONTIGUITY. example of the same tendency. The idea of a faUing body is so intensely suggested, that an effort of volition is neces- sary to keep the spectator from acting it out in his own person. It is often remarked that a painful recollection will haunt a person through life. This is an undue susceptibility to the influence of an idea, a morbid submission of the intellect to the will. Insanity is" the culmination of this peculiarity. The insane are very generally the victims of a diseased im- pression. Occasionally, this may give them pleasure, as when the idea takes the form of exorbitant vanity ; more often, however, the idea is morbid and gloomy, and still controls the actions. 13. Tlie working of Sympathy, Fellow-feeling, Pity, Compassion, Disinterestedness is an exception to the ordin- ary action of the will, which is to attain our own pleasures and remove our own pains. Self-conservation is the proper definition of AVill. But, by Sympathy proper, we are able to conceive the pains of others; and, in so doing, we are impelled to endeavour to alleviate them as if they were our own. This has been supposed to be a case of the working of the fixed idea, in the interests of fellow-beings into whose feel- ings we are enabled to enter through the medium of personal experience. The weak point in the explanation, however, is that a mere intellectual idea would be insufficient, in most circumstances, as a mo\dng power against our own personal interests strongly entertained. Accordingly, it is a safer and more likely assumption that, in the operation of Sympathy, there is a habit of sociability, engendered by long hereditary usage, of acting gregariously with our fellows. This would supply the missinir element of motive power, which alone seems wanting in the explanation furnished by the fixed idea. 14. Much of the ambition and the aspirations of human beings belongs rather to the sphere of fixed ideas, than to the sphere of volition prompted by pleasures. It is true that the things we aspire after, are usually calculated to give POINTS OF COMMUNITY OF SENSATION AND THOUCtHT. 363 US pleasure ; yet, very often, we indulge in ideal aspirations that are impracticable, and that, if we were masters of our- selves, we would disregard and repress. Unfortunately, however, a certain notion — say of power, wealth, grandeur — has fixed itself in our mind and keeps a persistent hold there, perverting the regular operation of the will, which would lead us to renounce whatever is hopeless or not worth the cost. Such phrases as ' insane ambition,' ' fixed idea,' 'overwhelming fascination,' are used to designate this not unfrequent phenomenon. Our regrets for what we have lost are generally out of proportion to the pleasure that the objects gave us. We may feel a sincere and a strong regret for the loss of some one related to us, who was an unmitigated burden and misery. The consideration of our pleasures and pains solely would cause this to be felt as a relief and a gratifica- tion ; but we cannot so banish a familiar idea even although painful, — we cannot forget, merely because our happiness would be increased by forgetting. Thoughts persist by a law that is not subject to the will ; and not only persist, but interfere with the course of our actions and the pursuit of our interests.* 15. The general doctrine now contended for is not a barren speculation ; if true, it bears important practical * To sum up. Two forces are at work in determining the influence of fixed ideas. One is the tendency of the idea of an action to become the action. This tendency is exemplified in its unmixed operation in such instances as the infection of particular crimes, and in the operation of sympathj- generally. The other principle is the tendency of an idea to persist in the mind, in consequence of its intensity, or rather the intensity of the feeling that accompanies it. The power of the will is baffled by great mental excitement under any circumstances. It may be for our interest to banish a particular idea, and to give a footing to other ideas, which our intellectual forcss are quite competent to suggest ; yet, when a feeling of any sort, whether pleasure or pain, or excitement that is neither, has allied itself with an idea, the forces of intellectual association and the force of the will are equally impotent to displace that idea. This is the way that fear operates to prevent a man from following out the regard to his own well-being. 364 EETENTIVENESS — LAW OF CONTIGUITY. inferences. In expressing and describing thought and the thinking process — an operation essential to our subject — the doctrine is of great service : it helps us, in some measure, to localize these processes; and the language that might other- wise be deemed figurative becomes literal. The imagina- tion of visible objects is a process of seeing ; the musician's imagination is hearing ; the phantasies of the cook and the gourmand tickle the palate. The identity between actual and revived feelings shortens our labour by enabling us to transfer much of our knowledge of the one to the other. The properties that we find to hold good of sensation in the actual, we may, after a certain allowance, ascribe to the ideal. Thus the qualities of the sense of sight in any one person, as, for example, its dis- criminating power, would belong likewise to the visual ideas. The senses are, in this way, a key to the intellect (see note C). 16. I return to the Association of Feelings of Movement. It generally happens that if we can perform a movement actually, we can also perform it mentally. Thus, we can go through in the mind the different steps of a dance ; in other words, the feelings of the successive evolutions have been associated together, as well as the movements themselves. It must not be supposed, however, that the adhesion of actual movements and the adhesion of mental movements run exactly parallel, and that if the one is perfect so is the other. We may sometimes see a mechanic able to go through the actual steps of a process, but unable to go through them in his mind ; the proof being that, in describing them to an- other party, he often forgets a step, and only remembers it by doing the thing. In this case, the actions are more adhesive than the traces of them. It is not easy to produce any in- stance to show, on the other hand, that a series of actions can be repeated mentall}' and yet not bodily ; for, as the mental actions are performed in the same circles, it usually needs only a volition, often the removal of a restraint merely, to bring them to the full length of actuating the muscles. ASSOCIATION OF FEELINGS OF MOVEMENT. 365 17. The principal field of examples of the association of pure feelings of muscular action, is the Voice. Most other cases are so complicated with sensation, that they do not answer our present purpose. In speech, we have a series of actions fixed in trains by association, and performable either actually or mentally at pleasure ; the mental action being nothing else than a sort of whisper, or approach to a whisper, instead of the full-spoken utterance. The child can repeat its catechism in a suppressed voice, as well as aloud. We can even acquire language mentally, or without speaking it out at all ; that is to say, we can bring about a pure mental adhesion. To a learner, this happens continually : for, in reading a book, one does not speak the words vocally ; the articulate adherence takes place from the first within the circles of ideation. Children, learning their lessons in school, must acquire the verbal successions in the same way. As a general rule, it is best to rehearse verbal exercises aloud, if they are to be performed aloud, just as in the case of other mechanical operations. The sense of hearing is thus brought in aid of the other associating links. Besides, by coming to the actual execution, we set on a current that is both inore energetic and larger in its sweep, inasmuch as it takes in the full operation of the muscles. In the early school acquirements, where everything has to be spoken out to the master, the audible repetition is the best ; in after days, when we go over a great deal of language merely as thought, or the silent links of action, the speaking out is not called for — it would be an unnecessary waste of time and muscular exertion.* 18. The circumstances that favour the cohesion of meiital trains of movement, are nearly the same as those already detailed for actual movements. A certain repetition is * In the processes of meditation and thought, we are constantly forming new combinations ; and these we can permanently retain, if we have dwelt upon them sufficiently long. A speaker meditating an address trusts to the adhesiveness of his verbal trains, although they have been all the while in the state of mere ideas, he not having spoken them aloud. 366 RETENTIVENESS — LAW OF CONTIGUITY. requisite ; more or less, according as the other circumstances are favourable, — namely, the general conditions of Concentra- tion and Retentiveness on the whole, and the special muscular conditions — Muscular Strength, Spontaneity, and Discriinination. AVe may, perhaps, assume a common character for the active organs in the same individual ; an activity of tem- perament that shows itself in every kind of exertion — in limbs, voice, eyes, and every part that is moved by muscle, — or a sluggish feebleness extending ahke over every kind of exercise. But this does not exclude specific differences of endowment in separate members, rendering the movements more adhesive in one than in the others. Thus, we may have a special development of the articulating members — the voice, tongue, and mouth, — through superiority in the corresponding centres. SENSATIONS OF THE SAME SENSE. 19. We here enter upon the class of acquisitions com- monly denominated under Perception, although extending much farther than the usual treatment under that head. There is a large portion of our education comprised here ; and, wherever this is the case, we are interested in ascertain- ing the circumstances that are favourable to the work. I shall consider, first, the adhesion of impressions of the same sense — homogeneovs impressions, as touches with touches, sounds with sounds, etc. In the inferior senses, there is little scope for exempli- fying the process. In the Organic Feelings, we might note the expectation of a series of painful feelings from the occurrence of some one, as in an illness. Even in Tastes, it is not usual to have any important associations of one with another. One might easily suppose the formation of a train of tastes, such that any one would suggest the others ; but instances are rare. So with Smell. If we frequently experience a succession of smells in one fixed order, an adhesion will be formed be- INDIVIDUAL IMPRESSIONS MADE SELF-SUBSISTING. 367 tween the different impressions ; and, in consequence, when one is presented, all the rest will be ready to arise in suc- cession, without the actual experience. In passing frequently- through a garden along the same track, we might come to acquire a succession of odours, and from any one anticipate the next, as dogs probably do. We seldom exist in a train of recollections of either Taste or Smell. They are difficult to realize to the full; and what we recover chiefly about them is their collaterals, — such as, the sentiment of liking or aversion that they pro- duced. By a great effort' of mind, we may approach very near the recovery of a smell that we have been extremely familiar with, as the odour of coffee ; and if we were more dependent on ideas of smell, we might perhaps succeed still better. Nevertheless, it must be admitted, that the recoverability of these states by mere mental association is of a low order. 20. IVie Idea. — At this point we cannot help adverting to the highest product of Intellect as given under the designation ' Idea'. A sensation, when able to persist after the original is gone and to sustain itself by mental power exclusively, is properly described as an Idea. The con- summating of this result is the effect of the retentive operation, no less than the coupling of tv/o or more sensa- tions in an aggregate or train : the retentive conditions are the same in both cases; the saixie effect of repetition that unites two impressions renders each member mentally self- sustaining. The separate taste of sugar, by repetition., impresses the mind more and more, and by this circumstance becomes gradually easier to retain in idea. The smell of a rose, after a thousand repetitions, comes much nearer to an independ- ent ideal persistence, than after twenty repetitions. So it is with all the senses, high and low. Apart altogether from the association of two or more distinct sensations in a group, or in a train, there is a fixing process going on with every individual sensation, rendering it more easy to retain when the original has passed away, and more vivid when, by 368 RETENTIVENESS — LAW OF CONTIGUITY. means of association, it is afterwards reproduced in idea. This is one great part of the education of the senses. The simplest impression that can be made, of Taste, Smell, Touch, Hearing, Sight, needs repetition in order to endure of its own accord ; even in the most persistent sense. Sight, the impressions on the infant mind that do not stir a strong feeling will be apt to vanish as soon as the eye is turned some other way. We might devote a separate illustration to this primitive phase of our retentiveness ; but I am not aware of any important applications of it, where there is not also a process of association between a plurality of sensations. Yet, it is proper to remark that the confirming of the separate impressions of sense, by which they are prepared for existing in the idea, is going on all the time that these links of coherence are in course of formation. 21. We pass to the more intellectual senses, — Touch, Hearing, and Sight. In touch, there are various classes of sensations, as already seen ; the more purely emotional, as pleasurable and painful contacts, and those entering into intellectual perceptions — as temperature (discriminative), plurality of points, roughness, smoothness, hardness, and combinations with muscular elements (weight, size, etc.). In all these, there is room for the associating principle to operate ; but our present illustration will keep in view chiefly the second of the two classes, or those concerned in the development of the Intellect. The sensation of any one surface, with all its peculiarities, is a complex thing ; it is an aggregate of impressions made on the skin, and having a certain arrangement and intensity. The face of a brush yields a number of impressions all occurring together ; these must take on a certain coherence, so that the sensation in its entireness may survive the actual contact. They must preserve their co-existence, and re- turn en masse at an after time. In comparing one surface with another, as in choosing a tooth brush, it is necessary only that a complex impression of one should survive a few ASSOCIATION OF SENSATIONS OF TOUCH. 369 seconds, while the other is felt ; in comparing one with some Other long since worn out, the permanence behoves to be much greater. So with surfaces of cloth or wood, of stone or metals, judged of by their asperity : an associating pro- cess must fuse the multiplex impression, in order that it may endure when the original is gone. Some surfaces are dis- tinguished by an aggregate of asperity and temperature, as the cold touch of a stone or a lump of metal, — in w^iich case the feeling of cold must cohere along with the other parts of the tactual impression. When muscular feelings and acts are superadded to the impressions made on the skin, we obtain the complex notions of touch, — such as combine feelings of weight, size, shape, and situation, with texture or surface. Here, an ad- hesion needs to take place between the tactile and mobile impressions. In order that a workman may recognize his tool by the hand alone, he must have had frequent experience of the complex feeling that characterizes its contact — the tactile impression of cold or warm, rough or smooth — -with the muscular impressions of weight, size, and shape ; these last qualities being determined b}^ the muscular exertion of the hand while grasping it. A sufficiency of repetition will so fuse all these together, that the tool can be identified the moment it is touched. In plastic operations, or in dealing with soft viscid matters requiring a particular consistency, as dough, clay, mortar, etc., it is necessary to attain firm impressions of different qualities and degrees of consistency, so as to know when the proper point has been exactly reached. This demands the cohesion of a complex sensation of touch ; in other words, a certain skin feeling of clamminess and rough- ness, with the muscular feeling of resistance, will have to cohere into one fixed whole that shall never waver, vary, or be obscured, by the concurrence of other differing im- pressions. The repetition iieedful for such practical dis- crimination as plastic operators require is usually very great, amounting to hundreds or thousands of contacts. 24 370 RETENTIVENESS — LAW OF CONTIGUITY. Individuals differ in their facility of fixing standard contacts by adhesive association. This is a case where it is impossible to mistake specialities of natural character. Some cannot, in a whole life, acquire the nicety that others possess after a few months' experience. Muscular sensibility must com- bine with skin sensibility ; and we may judge, from the nature of the case, which of the two is chiefly concerned. A delicate muscular sensibility will show itself in other combinations besides touch. Moreover, some of the feelings included under touch have scarcely anything to do with the skin, — as, for example, weight, size, and shape : great delicacy of discrimination in these has a purely muscular origin; while, in judging of the texture of a cloth or the smoothness of a piece of mahogany, the skin sensibility is the proper test, though even here not unaccompanied by free movement. By touch, therefore, under the operation of the cohesive property, we acquire fixed notions corresponding to the im- pressions made upon us by the objects that we handle. We contract engrained ideas of all the articles that we are in the custom of using. Thus, a workman is familiarized with his tools ; and every person comes to know the instruments and furniture of their dwellings. But, in order to appreciate the acquisitions of touch in their highest form, we must refer to the experience of the blind, who have no other sensation of solid and extended bodies. The impressions of sight are so much more enduring and revivable than any others, that we hardly ever think of a visible body other- wise than as seen by the eye : a workman, desiderating a hammer, thinks of its visible appearance, and not of its feel to his hand, although he is quite able to judge of it by this last feature. But the blind must think of objects as felt things ; the revived sensation in them is a projection on the hands, not on the eyes, and they alone are in a position to judge what is the natural permanence of skin impressions, and how far they can be recovered and lived in, when the reality is absent. Their thoughts, reveries, and dreams ASSOCIATIONS OF SOUND, 371 are touches, not sights. Not only is their power of tactile discrimination of a very exalted kind, but they also attain the higher state of realizing past touches as if fully present ; that is, supposing such realization of touch to be, under any circumstances, fully attainable. We must refer to the blind also for the association of trains, sequences, or succession of touches, made so coherent that any one may recall the entire chain. A blind man feeling his way along a wall by the hand, experiences in succession the different contacts ; and these, by repetition, are so fixed in his mind, that, when he is placed at any one point, he anticipates all that is to follow. Being under the necessity of always guiding his course by touch, he acquires coherent successions of feelings of contact, as other men acquire of sights. He knows his whereabouts in a room by touch ; the progress of his work, if he is engaged in handi- craft operations, is measured factually. 22. In acquiring associations of Sounds, we have to encounter the supplanting tendency of the voice in the most interesting instances, — namely, Articulate and Musical sounds. For, while intently listening to a speech, we are liable to follow the speaker with a suppressed articulation of our own, whereby we take the train of words into a vocal embrace, as well as receive it passively on the sense of hearing. This is an instance of concurring or complex association. As already observed in the other senses, the Ear, by re- petition, is formed to individual sounds, so as to retain them with ease after the cessation of the cause. The simplest sound is so far a complex impression that it needs a plastic operation to fix its parts together. Thus, an articulate syllable, ma, ha, is a really complex effect, occasioning a plurality of nervous currents ; and to make all these flow together in company and order demands a certain length of repetition. We have already illustrated this under the agglutination of movements. The next stage is the coherence of trains or successions of sound, of which 372 RETENTIVENESS — LAW OF CONTIGUITY. there are abundant examples. A simple air of music is a good illustration. Here, a number of sounds follow one another in a fixed order ; and, by frequently hearing them, we learn to pass from the one to the other by ideal anticipa- tion. When a sufficient number of notes have been struck to determine the air, the musician can proceed with all the rest. His education is made up of many hundreds of these sequences, built up by degrees under the plastic power of the mind. The specific determining circumstance in musical acquisi- tion is the quality of the ear, as shown by discrimination of pitch. That Discrimination is accompanied by Retentive- ness, we assume on general grounds — there being no facts to the contrary ; hence, the one may be taken as a criterion of the other. As regards the application of the three general conditions of Betentiveness — Repetition, Concentration, and the Adhesiveness of the system on the whole, — the first has to make up for the deficiency in the rest. The circum- stance of Concentration is principally manifested under natural liking, interest, or taste ; and taste follows, in a great measure, although not always in exact concomitance, the local endowment. Thus, a good musical ear, as tested by discrimination, would carr}' with it the taste, liking, or enjojTiient of music, and thus be the best of all motives to mental concentration. The same line of remark is applic- able to other acquisitions, and need not be repeated in every instance. Articulate sounds are made coherent in like manner. The good articulate ear is, to some extent, a modification of the musical ear. In so far as the letters of the alphabet are distinguished by being combinations of musical tones, the two sensibilities inust be the same. But, seeing that this is not wholly the case, we are not prepared to say that one may be always taken as evidence of the other. A third quality of vocal sounds is cadence or accent, — the basis of elocution, oratory, and rhythmical composition, and constituting the individual and national varieties of EDUCATION OF THE EYE FOE COLOUR. 373 accent. The ear retains not merely successions of articulate sounds, but also the cadence of their pronunciation ; and, when very susceptible to this class of effects, it shows itself in acquinng accent in mimicry, and in the elocution of the orator and the actor. The associations in the ear are only one part of the acquisitions in Music, Speech, and Elocution ; but they are, no doubt, the largest part. 23. Cohering trains and aggregates of the Sensations of Sight make, more than any other thing, perhaps more than all other things put together, the material of thought, memory, and imagination. That process of employing one sense as a substitute for others, principally avails itself of vision, the most retentive of them all. Thus it is, that objects thought of on account of their taste or smell are actually conceived under their visual aspect. The image of a rose dwells in the mind as a visual picture, and, in a very inferior degree, as a perpetuated impression of a sweet odour. Sensations of sight, as we have seen, are compounded of visual spectra and muscular feelings, A visible picture is, in fact (after allowing for span), a train of rapid movements of the eyes, hither and thither, over luminous points, lines, and surfaces. The education of the Eye goes through all the stages described for the other senses. There is, in the first place, an engrained impression of each separate Colour, — the result of repetition, enabling their several ideas to endure in the absence of the original, and to persist of their own accord when once suggested. The influence that gives the optical currents a facility in being induced and continued, so as to make one colour, as green, an object of comparison with other colours, is doubt- less the same plastic power that forms aggregates of coloured expanse, connecting together a succession of tints, as a rainbow, or a sunset. When we have passed repeatedly through the successive colours, the impression of one comes 374 EETENTIVENESS — LAW OF CONTIGUITY. to induce the next, and that the following, and so on in order. But we can scarcely advance a step in this illustra- tion without bringing in the movements of the eye, and the feelings belonging thereto. I can imagine an instance where the eyes, in a state of rest, have before them a number of colours produced in a fixed succession, flash after flash — red, orange, green, blue, violet, white, black, etc., — in which case a train of pure optical impressions would become fixed in the mind ; and the occurrence of the first would tend to revive an image of the second, third, etc., on to the last. The gradations of daylight and darkness are associated in this way. But, in the ordinary case of associated colours, they exist side by side, as in the colours of the landscape ; and we move the eyes to see them, and thereby incorporate the act and feeling of Movement with the sensations of light. If the eye is in this way habituated to a train of colours, the habituation consists in this, — that with each colour are associated both a movement of the eye and a second colour, and with this last movement and colour are connected a third movement and a new colour, and so on to the limit of the picture. Suppose, for example, a chain of fields of different lengths and of varying tints. The eye first sweeps over a yellow corn field, then passes to a grass field of double the length, then to a plantation of wood still longer. The image of the first is an impression of yellow, accom- panied with a definite sweep of the eye, and a corresponding continuance of the yellow impression ; the image of the second is a green effect, doubly prolonged, or accompanied with a double sweep of the eye, or the head, or both ; the third image is a different tint of green, embedded in a still wider muscular sweep. In these circumstances, and after due repetition, if the eye is impressed with the proper yellow hue along with the definite ocular movement accompanying it, the image of the first field will be reinstated, and the mental movement set, as it were, in an old and accustomed groove ; and there will be a transition from the optical impression of yellow in a given expanse, to the optical im- VISIBLE FORMS. 375 pression of a shade of green with an additional muscular sweep, and, lastly, to another shade of green with a still greater movement. These united impressions will be re- induced, one after another, as a consequence of contiguous growth. Let us divide the detailed illustration into the two cases of Outline Forms and Coloured Surfaces. In order to exemplify the class of Outline Forms, we will suppose a white ring on a dark ground. Here we have a line of light and a round sweep of the eye concurring in one impression. The eye, following the ring, imbibes a continuous effect of light while performing a round movement : an optical and a muscular impression are conjoined, the muscular predomin- ating; for the colour of the circumference is merely suffi- cient to give the lead to the ocular movement. The fixing of the image depends, almost exclusively, on the cohesion of movements of the muscles of the eye. Now, this case of the ring typifies a large class of important visual notions. The figures of geometry ; the symbols or ciphers of Algebra, Chemistry, and the other symbolical sciences ; the plans, diagrams, and outlines, used in the mechanical arts, — all depend for their retention, in the first instance, on the purely muscular endowments of the eye. Written language fur- nishes another class of visible forms ; and, in the fine arts of Sculpture and Architecture, form is the chief matter of the artist's consideration. The circumstances that favour this acquisition are, as before, partly general and partly special. The genera.1 adhe- siveness of the system being assumed, the special condition is retentiveness for Ocular Movements. According to the assumption formerly made, this will be found accompanying the special power of discrimination in the muscles of the eye, — the consequence, no doubt, of a high development in the centres for regulating their movements. Next to the general and the local retentiveness, we must advert to the mental Concentration, as due more especially to interest, taste, or liking, or a regard to the end to be served. 376 EETEXTIVENESS — LAW OF COXTIGriTT. We have noted three different classes of outline forms, all ■equally retainable, so far as the muscular retentiveness of the eye is concerned, but whose retention is stimulated by very different motives. There are scientific forms, as the figures of Euclid ; arbitrary forms, as in written language ; and artistic forms. The attention to the first is prompted by wliatever feelings constitute the scientific interest or taste ; the second class, the arbitrary forms of language, are aided by our interest in the ends of language, either for ordinary pur- poses, or for the studies of the scholar ; the attention to the last is stimulated by the sensibility to Art. Looking at the peculiarities of these several cases, we can note that there is a greater concentration of mind upon the forms of Science and of Art, these being few and important, than upon the symbols of language, which are numerous and individually unimportant in the comparison. One would say that, in the case of language and arbitrary symbols, a high natural, disinterested, or unstimulated adhesiveness, would be requi- site. A strong motive for concentrating the mind applies better to few things intensely held, than to a great multitude. The power of remembering a vast number of arbitrary visible marks may be set down as depending, partly, on a good general adhesiveness, and, partly, on the special muscular adhesiveness of the organ of vision. The acquiring of the Chinese language, with its many thousand characters, is perhaps the most striking example. The geographical memory for maps falls under the same head ; only, in this instance, there may be the prompting of a more powerful special interest. 24. We turn next to Coloured Surfaces, or those visual effects where light and shade, colour and lustre, prominently enter, — as in a landscape, a spectacle, a picture, a room, a human face. Here, the object consists of an aggregate of masses of colour, which are associated by whatever force of retentiveness or adhesion belongs to the impressions of colour. If we repeatedly gaze at a picture, its different patches of colour seize hold of the mind and connect them- COLOURED SURFACES. 377 selves in their natural order, so that the one can recall the rest, and the whole can exist and be held in the view, when the actual object is no longer present. Masses of coloured decoration, the colours' of rich calicoes, and the variegated dresses of an assembly of people, exemplify the situation where colour predominates over form, and where the re- tentive n ess is much more optical than muscular. The im- pressibility to colour is put to the test by the attempt to recall objects like these. This attribute has no necessary connexion with the muscular susceptibility ; the two belong to independent organs, and follow different laws. Persons highly endowed as regards Colour have one of the gifts of a pictorial artist — painter or poet. The easy recollection or revival of scenes, and objects, and human faces is necessary in order to work as a combiner in this class of things. 25. As in other cases, a superior hold of coloured sur- faces rests upon general, combined with local, adhesiveness. A fine sense for shades of colour is a sufficient proof of a high local endowinent, which will show itself in a corre- sponding power of retentiveness. There can be no reason- able doubt that the sense of colour is a primary sensibility of the mind ; and, when of a high order, its consequences on the intellectual character are numerous and marked. It is not only identical with a facility of remembering scenes and pictures, and shades of colour ; it also generates a strong interest in the concrete, pictorial, and poetic aspects of the world, and a repulsion to the scientific point of view, which deals with nature by means of abstractions and naked symbols. We are not to look for the scientific aptitudes in a mind highly sensitive to colour. Besides, then, the positive conditions already enumerated of retentiveness to Form, we should add, as a negative condition, a moderate, or even inferior, susceptibility to Colour. The scientific man, the verbal scholar, and the artist in forms, are all the more powerful in their respective walks, that the impressibility of the eye to colour is reduced to a minimum. The ordinary limits of the human mind 378 RETENTIVENESS — LAW OF CONTIGUITY. seem not to permit a high development in two such divergent lines of talent. 26. As a wide ranging and important example of association within the same sense, we may quote the advance that acquisition makes in the span or grasp of an instantaneous sensation. In the three higher senses — Touch, Hearing, Sight, — the element of expanse, plurality, or multiplicity, is manifested on a considerable scale. It occurs first, prior to all acquisition, in the range of a single instantaneous exercise of sense, to be afterwards extended by association. What the primitive compass may be in the case of the several senses, we can do little more than vaguely divine ; what it is, after our education has advanced some way, we can more readily judge. Most conspicuous and unmistakable is the sense of Sight. Making a certain allowance for what may be supposed a primitive span in the case of vision, we can pronounce this to be largely improved upon through practice or repetition. We cannot exceed the spherical segment included in the retina, at any one glance ; but we can improve upon the fulness and distinctness of the detail as realized to the view, in consequence of familiarity with the picture or scene. x\ll this grows with our growth ; its progress follows the general laws of intellectual coherence that have been already recognized. The case of Touch is substantially the same, although inferior in degree ; the difference being describable in terms suit- able to the inferiority of touch as an intellectual sense. The reference included also the sense of Hearing. True, the circum- stance of spatial expanse is not here present ; but there is plurality in another way. In listening to a full band, a great many sounds reach the ear at the same moment, and, of these, some at least are instantaneously grasped. Here, too, the grasp has a certain compass by nature, aiid admits of being enlarged by acquisition. The skilled musician has the immediate perception of a much larger plurality than the untutored ear. 27. It is, also, to be remarked that the cumulative operation of contiguity is interrupted by the absence of uniformity of con- junction in the things occurring together ; out of which circum- stance arises a new class of mental phenomena. If only one CUMULATIVE ASSOCIATION INTERRUPTED. 379 species of ring were ever presented to the view, and if the specific colour were unknown except in that one object, there would be an inseparable contiguous association of that form and colour : neither could ever present itself without the other. But nearly every simple impression known to us exists in various connexions ; a pure white colour, for example, is found in snow, in foam, in cloud, etc. Hence, the effect of contiguity would be to bring up all these objects when a white colour is suggested ; and some- times we do, in fact, bring a host of individuals into view, by the suggestion of a common property. At other times, the mind, distracted by the number and variety of the connecting links, remains unmoved by any ; or, from collateral influences in favour of some one, singles out that one to the neglect of the rest (see Compound Association). It will hence be apparent that the occurrence of new conjunc- tions with a familiar property has a dissociating effect. Liquidity is at first associated with the other properties of water ; whin we become familiar with ice, this connexion is partially loosened. Certain properties at first exclusively allied with liquidity are now also allied with solidity, giving a second alternative ; the additional experience of steam affording a third alternative. This is the situa- tion described also under the name Abstraction or the Abstract Idea. By a fallacious tendency of the mind, the alternate connexion has been viewed as a possibility of separate existence : because ' white' has many alternative connexions, the supposition has been made, and received, that whiteness can exist out of all connexions. 28. It is further to be noted, with reference to the process of acquisition, that the vast complicacy of the things to be acquired, of which the visible world is the most signal example, cannot be overtaken except by a system oi patching , or employing the old to piece the new. Looking down from a height upon a large city with its rural envii'onment, we form a coherent picture of the whole, which we can retain even in minute lineaments. This is possible only because we have pi'eviously acquired coherent mages of streets and spires, and fields and trees ; and have connected them in aggregates not much differing from the present. We merely tack together our previous elements in a somewhat novel arrangement upon this new occasion ; and the whole stress of the memory lies in consolidating the new grouping. 380 RETENTIVENESS — LAW OF CONTIGUITY. SENSATIONS OF DIFFERENT SENSES. The concurrence of Sensations in one common stream of consciousness, — on the same cerebral highway, — enables those of different senses to be associated as readily as the sensations of the same sense. \\e will now, therefore, review the more remarkable instances that arise out of this heterogeneous concurrence. In so doing, it will be convenient to include also Movements — actual and ideal. 29. Movements with Sensations. — It was previously re- marked (p. 331) that there are few perfect associations of mere movement ; the sense of the effect contributing most of the cohesiveness of a train of muscular actions. There is, therefore, the union of a movement with a sensation at each stage of the performance of a complicated operation. Even the simple case of walking requires that the expected contact of the foot with solid ground should concur with the motor stimulus of associated movements. Under the same head, we may place the association of Actions with sensible Signs ; as in all that department of lingual acquisition wherein names have the meaning of command, direction, guidance, control. Every movement that we make is connected with a certain form of words, or a particular signal, which may set it on at any time. The child learns to connect vocal sounds with its various actions, and so becomes amenable to command and direc- tion ; and the education is continued all through life. The signs for indicating action may be various : the notes of the bugle, the signals at sea, the directions posted up on the walls, have all this acquired power of commanding move- ments. The same association enters into the education of animals : the horse and the dog soon learn to connect specific actions with the language, tones, and looks of human beings.* Long before children possess the power of utterance theinselves, many of their actions are associ- ated with the sounds of language as uttered by others. * The omnibus horse resumes his pace on the sound of shutting the door. IDEAS OF MOVEMENT WITH SENSATIONS. 381 30. Muscidar Ideas with Sensations. — The enduring forms, impressions, or Ideas of Movement, are associated with Sen- sations ; and the two things recall each other. In the three higher senses, we have seen that there is an association of these two elements ; many tactile, audible, and ^'isible sen- sations being a coalition of the two. Under Sight, we con- nect the visible appearances of objects wdth their weight, hardness, and tenacity, — qualities mostly muscular in their perception. Having experience of the weight of a piece of stone of a certain appearance, we associate the appearance with the weight, — the one suggesting the other ; so with hardness or tenacity. In this way, we have an associated connexion between substances and their uses founded on these properties. We acquire a strong feeling of the differ- ence between timber and stone, and between stone and metal, and demand that each should be differently proportioned in all kinds of erections and mechanical operations. It has been remarked that our sense of Architectural proportions is founded on our experience of stone, and would require to be re-adjusted if iron were as universally employed. If the specific gra\aty of the rocky materials of the globe had been equal to lead, instead of being about two and a half times water, our sense of the weight of every piece of stone would have been four times as gi'eat as at present, and we should consequently have exacted, for the satisfaction of the eye, far more massive proportions in every kind of stone work* The knowledge of the distance and the direction of Sounds (Hearing, § 13), is, in reality, an association between sounds and movements, or else muscular ideas. The pro- perties themselves are, not audible, but locomotive properties, — signified to the mind by sensations of sound. 31. Sensations unth Sensations. — Under this head allusion * That is, supposing there was no increased tenacity, or power to resist crushing. Iron buildings are less massive than stone, notwithstanding the greater density of the material ; but, in this case, the greater strength of the substance comes into play, and the employment of hollow and slender forms takes off from the weight to be supported. 382 RETENTIVENESS — LAW OF CONTIGUITY. might be made to all the combinations that would arise by taking each sense along with every other : organic sensations with tastes and sinells, with touches, sounds, and sights ; tastes with smells, etc. ; smells with touches, and so on. But it will suffice to quote the associations among the three higher senses. Touches are associated with sounds, when a body struck tells by the ring how it would feel,— as in discriminating stone, wood, glass, pottery, etc. This is a very abundant, and generally very secure, adhesion. Touches are associated with sights, in the great compre- hensive case of connecting the tactile properties of things with their visible appearance, whereby the one can instantly bring to mind the other. We associate the tangible qualities of roughness, smoothness, solidity, liquidity, viscidity, with the characteristic impressions they make on the eye ; and we can at any time recall the touch by the sight, or the sight by the touch. We can distinguish metals, stones, wood, cloths, leaves, flowers, by both senses ; and we form an association between the tactile and the visible impres- sions. Each person has a large amount of knowledge existing in the shape of associated touches and sights. We connect, likewise, the form, as revealed to the touch, with the visible forms, and thus make the one confirm the other. Our notion of Figure is, in fact, a coalition of different impressions ; and this gives to it a more com- plete and perfect character. I shall speak of this again presently. Sounds are associated with sights in innumerable in- stances. We connect the visible appearances of bodies with the noise they make when struck,— as a glass, a spoon, a book, a hat. We associate an instrument of music with the peculiar quality of its note ; we connect animals with their vocal utterance. So with human beings ; each person known to us having a distinctive voice. In acquiring languages, there are two cases of the association. Every visible object is connected with the sound of its name — sun, CONDITIONS OP HETEROGENEOUS ASSOCIATION. 383 mountain, house, etc. ; and, in learning to read, the sounds are associated with the written and printed characters.* 32. With regard to the present class of heterogeneous associations, it is to be supposed that the rapiditi/ of the adhedon will vary with the adhesive quality of each of the two senses entering into the combination. Thus, when sounds are connected with sights, the goodness of the ear and the retentiveness of the eye will both contribute to the adhesion. Whence, all associations with sight will come sooner to maturity than the connexions formed among the inferior sensations. It is this circumstance that puts sight forward as the representative sense. Things that are seen have a more glorious resurrection in the mind than any others ; we choose to conceive the objects of nature as they appear to the eye, rather than as they aifect the ear or the touch. Of all the ways that an orange can strike the senses, the visible aspect is, by pre-eminence, its revived manifesta- tion—its ' idea '. It may be supposed that the association of sights with sights is the best of alb the adhesive growths among sensations; sight being assumed as the most perfect of the senses. This, however, is open to an important quahfication, — namely, that the shock of * Associates with Smell. — Although odour as such is not remarkable for natural persistence in idea, — in other words, although we do not live con- tinuously in ideas of smell, — yet odours in their actual presence are very highly discriminated, and very suggestive of objects and situations embodied in the higher senses. Both emotions and intellectual images are copiously revived at the instance of present odours. The olfactory bulb and gangUon, so marked and conspicuous in the base of the brain, is supposed to favour this association. Not only is it a considerable centre of sense in itself, but it is believed to ramify wide and deep in the cerebral cortex where it mingles with the sense nerves of the other senses. As compared with Taste, which is the nearest parallel to Smell, there is an apparent superiority in the intel- lectual outgoings. As the development of Smell is not at its highest in man, being greatly surpassed in the dog, we may easily suppose that the imagery and associations are correspondingly enlarged and predominant. It is remarkable that deficiency or absence of smell is not uncommon in human beings, and that the deficiency is very little noticed ; showing that, as a rule, it does not occupy a large fraction of conscious life, whether actual or ideal. 384 EETENTIVBNESS — LAW OF CONTIGUITY. difference between the two members of a couple enters into the impressiveness of the union, and the consequent effectiveness of the adhesion. It may thus happen tliat the association of a sound and a sight shall surpass in promptitude and maturity the association of sight with sight. The well-known topical memory of the ancient orators ex- emplifies the superiority of adhesions with sight over other trains of ideas. Instead of connecting the parts of a speech by the word memory, the orator found a certain gain in facility of recollection by attaching the different portions to the several parts of a well-known building, or other visible expanse. The aspects of the assumed building being securely united, the requirement was to connect with sufficient firmness the separate heads of the oration with the selected portions. Something of the same principle of preferential and economical linkings enters into all the modern devices of artificial memory. PERCEPTION. 33. Perception and Sensation agree in this, — that, in both, we are in contact with actuality or the actual world, and have not entered the sphere of pure Ideation. It is true we have some difficulty in quoting Sensation in its abstract purity ; it being generally combined with what belongs to the world of ideas. Still, there is a something about it that the idea proper does not possess ; and that something is what we describe in such terms as reality, actuality, presentations, contact with the outside world, and so forth. As distinct from sensation, Perception is something added to the actuality of sensation proper. It is, in fact, that element of the ideal that gets so mixed up or associated with the actual as to be the chief obstacle to our quoting sensations, purely and properly so called. The process of Association by Contiguity is pei-petually forming unions among concurring impressions of the same sense or of different senses. The upshot or result of this process is, that the occurrence of any one in the actual resuscitates the others in the ideal. Such is the general law of con- PERCEPTION AS DISTINCT FROM SENSATION. 385 tiguity. There is, however, a Hmited, although very wide ranging, class of cases where the name Perception is more usuall}^ applied. It supposes an actuality, or actual property, present to some one sense, and for the time remaining there, while a number of other properties are represented ideally in fusion with it. We might cease attending to the actual presentation, and might take hold of the entire complex, holding it in the mind as an idea or memory ; it would then cease to be a perception. There are many instances where a thing presented to the sense carries with it, in intimate fusion, ideas or elements not presented. AVe can cite, for example, the emotions that gather round many objects of sense, and were not felt at the earlier stages of our experiencing such objects as sensations. The emotional association may be so intimate and so secure that we treat it as part and parcel of the sensation itself, forgetting its history as a matter of growth. This is in some degree parallel to perception, but is not usually included under that designation. The importance attached to the name as designating a class of mental products grows out of certain doubtful or controverted issues, where it is a matter of discussion whether what is taken for a mere sensation — something primitive, pure and simple — be not in reality a fusion of elements that have come together from different quarters of the sphere of sense. The first characteristic class of so-called perceptions is the reference of a sensation to an outward cause or position in the outer world. When we see a candle flame, we at once realize, along with the visible picture, a complexity of circumstances that the visual sensation could never have given, in the first instance ; although, from the immediacy and force of the suggestion, we are led to suppose that it might have done so. This, then, gives birth to a special department of psychological inquiry, — namely, the origin and growth of these peculiar associations. We have to resolve what we believe to be an illusion into its historic growth. 25 386 RETENTIVENESS — LAW OF CONTIGFITT. Another class of perceptions includes our assigning the local seat of contacts with the surface of our body. There is here the same illusion of immediate or intuitive knowledge, and the same possibility of resolving the illusion by assign- ing the manner of its growth as an acquisition. The problem of the origin of our notion of Space ranks under this head. We seem to ourselves to see, not merely a visual expanse of coloured surface, but, along with that, the distances from the eye of the different parts, the actual magnitudes of the different objects, and even their sensible qualities as felt by other senses. So subtle and difficult is the problem thus presented, that parties are ranged on both sides of the matter at issue ; some contending that space relations properly so called are seen at once by vision pure and simple ; others assigning to the supposed visual complex a specific derivation — in other words, ranking it as not a sensation but a perception. Perception is the word used by the older psychologists for the peculiar product here described. The prevailing usage now is to substitute Perce'pt for the same meaning, — which saves an ambiguity in using the same word both for an intellectual faculty and for its result. External Perception. AVe have now, at this point, to consider the perception and the knowledge of the Material AYorld, which come through the muscular feelings and the sensations, by their associations with one another. The manner of attaining to this knowledge, its exact nature, and the degree of certainty attaching to it, give rise to some of the greatest questions of metaphysical philosophy. Two problems especially call for notice at this stage. The first is the origin of the percep- tions we owe to vision, — namely, the Forms and Magnitudes of External Bodies, and their Distances from the eye. Ever since these perceptions were affirmed by Berkeley to be, not original, but acquired, they have formed a subject of discussion with metaphysical writers. The second question ASSOCIATIONS WITH THE ACTIVITY OF THE ETE. 387 relates to the Perception of an External and Material World. It grew out of the other, both historically and naturally, and was the prominent metaphysical question of the eighteenth century. 34. Of the Perception of the Distances and the Magnitudes of External Bodies. — The distinctive susceptibility of the eye is for Colour. This is the effect specific to it as a sense. But the feeling of Colour bij itself implies no knowledge of any outward object, as a cause or a thing wherein the colour inheres. It is simply a mental effect or influence, — a feeling or conscious state, which we should be able to distinguish from other conscious states, — as, for example, a smell or a sound. We should also be able to mark the difference be- tween it and others of the same kind, more or less vivid, more or less enduring, inore or less voluminous. So we should distinguish the qualitative differences between one colour and another. Pleasure or pain, with discrimination of intensitj^ and of duration, would attach to the mere sensation of colour. Knowledge or belief in an external or material coloured body, there would apparently be none. But, when we add the Active or Muscular sensibilitj' of the eye, we obtain new products. The sweep of the eye over the coloured field gives a feeling of a definite amount of action, an exercise of internal power ; which is something totally different from the passive feeling of light. This action has many various modes, all of the same quality, but all distinctively felt and recognized hy us. Thus, the move- ments may be in any direction — horizontal, vertical, or slanting ; and every one of these movements is felt as dif- ferent from every other. In addition to these, there are the movements of adjustment of the eye, in accordance with differences in the remoteness of objects. We have distinctive feelings belonging to these different adjustments, just as we have for the different movements across the field of view. If the eyes are first adjusted to clear vision for an object six inches from the eye, and afterwards change their adjustment to suit an object six feet distant, we are distinctly conscious of 388 RETENTIVENESS — LAW OF CONTIGUITY. the change, and of the degree or amount of it ; we know that the change is greater than in extending the adjustment to a three-feet distance, while it is less than we should have to go through for a twenty-feet distance. Thus, in the alterations of the eyes for near and far, we have a distinctive conscious- ness of amount or degree, — no less than in the movements for right and left, up and down. Feelings having the character of activity are thus incorporated with the sensibility to colour: the luminous impression is associated with exertion on our part, and is no longer a purely passive state. We find that the light changes as our activity changes ; we recognize in it a certain connexion with our movements ; an association springs up between the passive feeling and the active energies of the visual organ, and of the body generally, — the changes of view involving movements of the head and trunk, as well as the sweep of the eye within its own orbit. We have not yet attained to the perception or knowledge of any outward thing as the source of colour, or as the occa- sion of the varying movements and adjustments of the eyes. We have distinctive feelings of colour, the varying conscious- ness of active energies, and the association of the two in one fact, but nothing to reveal or suggest external things; we_ have merely the means of comparing a number of various mental states. Nor do I see how, with the eye alone, we can ever pass from the internal consciousness to the external per- ception — to the recognition, knowledge, and belief of things out of, or apart from, ourselves, the causes of those internal states. Many have contended for, and many more have assumed, this power as attaching to vision. But, in so doing, they seem to have fallen into a confusion of idea respecting the mental nature of this perception of an outer world, — as I shall now endeavour to explain. 35. It is admitted that the recognition of a world apart from self is mixed up with the perception of such qualities as Extension, Form, and Remoteness, called Primary quali- ties of matter. Heat, Odour, Taste, Colour, alone, do not suggest external and independent objects ; being, for this PERCEPTION OF DISTANCE FROM THE EYE. 38^ reason, termed the Secondary qualities of bodies. Let us consider, therefore, the two facts of Distance and Exten- sion, — both of which imply outward existence, in so far as we recognize and believe in the reality of a material world apart from the mind. With regard to these two qualities — namely, (1) the distance of a thing from the seeing eye, and (2) the real dimensions of a body in space, — I af&rm that they cannot be perceived or known through the medium of sight alone (leaving out, for the present, hereditary experience). Take, first, the case of Distance, or remoteness. It appears to me that the very meaning of this quality — the full import of the fact implied in it — is such as cannot be taken in by mere sight. For, what is meant by an object being four yards distant from where we stand? I imagine that, among other things, we understand this — namely, that it would take a certain number of paces to come up to it, or to reduce the distance from four yards, say to one yard. The possibility of a certain amount of locomotion is implied in the very idea of distance. The eye would be distinctly aware of a change, when the distance was reduced from four yards to one ; but it has of itself no knowledge of the cause or accompanying incidents of that change. These are measured by our other activities, and, in the case of great distances, by the locomotive energy and continuance requisite to pass from one to the other. In the case of objects within reach of the hand, the movements of the arm give the measure of distance ; they supply the accom- panying fact that makes distance something more than a mere visible impression. When we say, that a thing has been shifted from a position of six inches' distance from the eye to a position of twelve, we imply that, with the change of ocular effect, there has been another change correspond- ing to a certain definite movement of the hand and arm in a forward direction ; and, unless by supposing this additional action, we have no key whatever to the alteration that has come over our visible image. I say, therefore, that distance 390 EETENTIVENESS — LAW OF CONTIGUITY. could not at first be perceived by the eye, because the idea of distance, by its very nature, impHes feelings and measure- ments out of the eye, and located in the other active organs, ■ — the locomotive and other moving members. If our notion of distance did not reveal to us the fact that by so many steps, or by a certain swing of the arm or bend of the body, we should make a definite change in the appearance of the object, it would not be a notion of distance ; there might be an ocular effect, but not a revelation of distance. Granted that the eye is very distinctly affected by every change in the remoteness of a visible object from six inches to a mile, that it recognizes a variation of impression all through this interval, this would not answer the question — How far is the object removed at each step? I do not see, even, how it could tell which way the thing was moving. The actual distance means so many inches, feet, or yards ; and of these we should have no measure by the eye. Indeed, they have no relevancy as regards the eye ; they concern the loco- motive and other mechanical movements, but not the move- ments of sight. With the active exertion of the body in locomotion we have a definite muscular feeling ; we recognize one f xertion as greater or less than another ; the feeling of a long stride is different from a short ; six paces are attended by a different consciousness from four. We acquire permanent and revivable impressions of these exertions, when any one has been often repeated, — as, for example, pacing the length of a room. We can compare any new case with this old habitual effort, and there results a consciousness of more or less. This I take to be our starting-point in the feeling of distance traversed, or of linear extension in general ; this is the source of our perception, and the measure and standard of reference, when we arrive at the same notion by other means. When, along with a forward movement, we behold a steadily varying change of appearance in the objects before us, we associate the change with the locomotive effort ; and, after many repetitions, we firmly connect the one with the Berkeley's theory of vision. 391 other. We then know what fact accompanies (1) a certain muscular tension of the eye-ball, ('2) a definite feeling of convergence of the two eyes, (3) a certain dissimilarity of the two pictures, (4) a given amount of clearness or haziness of prospect, and (5) a fixed or varying retinal magnitude. These ocular feelings, both optical and muscular, have been connected with the further and distinct experience of a definite locomotive energy, to be expended to bring about a definite change in their amount or degree. Apart from this association, the eye-feelings might be contrasted or com- pared, or connected with other eye-feelings ; but there would be no further suggestion in the case. The collective feelings that we have when the ciliary muscle is relaxed, when the eyes are parallel (vision being distinct), when the two pictures are the same, when a slight haze covers the image, and when the retinal magnitude of familiar forms is small— all imply, as the result of foregone experience, that a prolonged effort of locomotion would be requisite to convert these feelings into their extreme opposites. This suggestion of locomotive effort is the fact, and the whole fact, named real Distance from the spectator. Such, as translated into the language of our more advanced Psychology, is the Berkleyan view of the perception of Distance — a view that long seemed, to the great mass of scientific men, to be irresistible ; while very few became converts to Berkeley's doctrine of the Perception of a Matei'ial World, to which the theory of Vision was a prelude. But, in om- own day, the explanation of Distance by association has been impugned ; and the opposite, or instinctive, theory reverted to. Many even of the latest objections to the theory apply only to imperfections in the author's mode of stating it. In Berkeley's time, the muscular or active sensibility of the human system had no distinct place in the account of the senses ; it was noticed only as a part of Touch. Berkeley's language, representing our perception of distance as an association of Sight and Touch, must be set down as wholly inaccurate and inadequate. But, when we substitute for Touch the entire aggregate of our Move- 392 RETENTIVENESS — LAW OF CONTIGUITY. merits, there is presented an altogether new front, to which the attack has not been adequately directed. The strength of the case against any form of the theory lies principally iii the great maturity of the perception of Distance at a very early period of life, — which seems out of proportion to the usual pace of acquisition ; while the means and opportunities of the needful experience are represented, by opponents, as altogether incommensurate to the result. These opportunities, however, are greatly understated. In particular, two leading circumstances are left out of the account. In the first place, for the experience of Touch (in Berkeley's language) — which in the infant must be very small from the immaturity of the organs, not to speak of their limited range, — substitute the entire movements of the body, however arising. The locomotion in the arms of the nurse, is a part of the experi- ence of changing distance. The infant must have a muscular sensibility in being carried from place to place, as well as in walking on its own limbs ; whence, its education in real distance begins from the lirst moment of life, and is kept in constant daily practice. If we suppose it carried from one spot to another, on an average twenty times in a day, it would have in the first year seven thousand lessons in distances on the large scale, besides the smaller experiments with its own arms and body as it acquires the self-moving aptitude. The second fact overlooked is the remarkable delicacy of the appreciation of changes of retinal viagnitude ; which, for all changes of place, are great and conspicuous. This particular sensibility ranks, in point of acuteness and discrimination, the first of all human sensibilities. It is a combination of our two most sensitive organs — the retina and the ocular group of muscles. Whenever we desire to obtain a delicate measure- ment of any quality, we transform it into visible magnitude, — as in the balance and the thermometer. Consider, then, that the infant, in being carried from one part of a room to another, experiences the most extraordinary expansion or contraction of its retinal images ; an effect that must be soon stamped on its memory in association with the attendant experience, locomotive or other. In mature life, we are rarely conscious of these retinal changes, being accustomed regularly to translate the fluctuating EXTENSION AS ASSOCIATED SIGHT AND LOCOMOTION. 393 appearances into some constant real magnitude ; but we may easily judge of their efficiency by adverting to the remarkable suggestiveness of a vista. Now, until the effect of the incessant education in couphng locomotive movements with the impressive alterations of retinal magnitude (together w^ith all the other ocular changes) is fully allowed for, we cannot say how far the early experience of infancy is insufficient to form the associations l)etween Distance and its visible signs. The question has never been argued on this basis. It would be easy to adduce many inconsistencies and fatal admissions on the part of the advocates of the instinctive theory ; and all the difficulties attaching to innate ideas generally have to be encountered in this instance. If it be admitted that Distance is something beyond a purely ocular impression, there is the im- probability of an innate alliance between two senses ; we do not smell sounds, nor hear tastes. This improbability must be met by unequivocal facts.* 36. If we, next, attend to the sweep of the eye over the field of view, as required by an object extended laterally, * It is stated by Mr. Abbot, that, though the eye possesses the power of perceiving distance, it cannot possess any idea of the amount of walking necessaiy to pass over it [Sight and Touch, p. 134). !Mr. Mill justly observes that this siuTenders the whole question : ' If we saw distance, we should not need to learn by experience what distance we saw '. To whicli ]Mr. Abbot replies : ' He might just as well say that to admit that a person can be taught to distinguish musical tones with accuracy, is to admit that they are not perceived by the ear. If we heard the tunes we should not need to learn what tunes we heard. Certainly we are no less beholden to experience for the accurate knowledge of the distances we move through.' Mr. Abbot's parallel is not in point. The dispute is not as to the intrinsic sensibility of the eye, for colour, etc., the only thing analogous to the sensibility of the ear to the pitch of a sound ; it respects an added or foreign experience. The true parallel would be our hearing distance, — whicli also we do, by an acquired pro- cess. It is admitted that we need no education to tell the ear that it iiears pitch, or to tell the eye that it sees colour, but we do want experience to tell us of another property, discovered by another sensibility, that such property accompanies a sensation of sight or of sound. Tlie dispute is interminable and futile, so long as Distance is believed to mean something exclusive of possible locomotion. If distance be more tlian the intrinsic sensibility of the eye — to light, colour, visible movement, and visible form — and yet less than our locomotive experience, what is it ? 394 EETENTIVENESS LAW OF CONTIGUITY. we shall find, in the same manner, that this sweep gives a most distinctive consciousness, so that a larger sweep can be discriminated from a smaller ; but it gives no information besides. It tells of no outward thing, so far as I can make out. Certainly, it does not tell of extension, as Eeal Magni- tude, — for this simple reason, that extension means a given movement of body or limb. If I say that a log of wood I see before me is six yards long, I mean that it would take a certain number of my paces to traverse its length : the visual impression of itself cannot mean or imply any fact of this kind, until experience has connected the sweep of the eye with the sweep of the legs or other movable parts. Accordingly, I hold, as regards Extension in general, that this is a feeling derived, in the first instance, from the locomotive or moving organs : that a definite amount of movement of these comes to be associated with the sweep and adjustments and other effects of the eye ; and that the notion, when full grown, is a compound of locomotion, touch, and \"ision, any one implying and recalling the others. A certain movement of the eye, as the sweep over a table, gives us the sense of that table's magnitude, when it recalls or revives the extent and direction of arm movement neces- sary to compass the length, breadth, and height of the table. Previous to this experience, the sight of the table would be a mere visible effect, differing consciously from other visible effects, and not suggesting any foreign effect whatever. It could not suggest Magnitude, because magni- tude is not magnitude, if it do not mean the extent of move- ment of the arms or limbs that would be needed to compass the object ; and this can be gained in no way but through actual trial by these very organs. 37. The conclusion, therefore, is, — that Extension, Size, or Magnitude, owes, not only its origin, but its essential import, or meaning, to a combination of different effects associated together under the cohesive principle we are now consider- ing. Extension, or space, as a quality, has no other origin, and no other meaning, than the association of these different HAMILTON ON EXTENSION. 395 sensitive and motor effects. The coalition of sensations of sight and of touch with felt motive energies, explains every- thing that belongs to our notion of extended magnitude or SPACE. This view has both its supporters and its opponents. Of the opposition, I shall content myself with referring to Sir Wilham Hamilton, who expresses himself on the subject in the following terms : — ' The opinions so generally pre- valent, that through touch, or touch and muscular feeling, or touch and sight, or touch, muscular feeling, and sight, — that through these senses, exclusively, we are percipient of extension, etc., I do not admit. On the contrary, I hold that all sensations, whatsoever, of which we are conscious, as one out of another, eo ipso, afford us the condition of immediately and necessarily apprehending extension ; for in the consciousness itself of such reciprocal outness is actuall}^ involved a perception of difference of place in space, and, consequently, of the extended ' {Dissertations on Eeid, p. 861).* The statement here made admits of two interpre- * The circumstance that the eye contains within itself an active element, — namely, its very numerous and acutelj' felt movements,— renders vision some- thing beyond optical sensation. Hamilton does not advert to this fact, and seems to maintain that, even excluding the consciousness of ocular movement, the eye can be the means of suggesting space. Now, so far is this from being proved, that a verj' strong case may be made to show that the optical sensi- bility does not give even visible form (to give which would be to step into the province of another part of the \-isual mechanism). In following a wide ranging movement, or, in expatiating over a large prospect, we must move the eyes, or the head ; and probably every one would allow that, in such a case, feelings of movement make a part of our sensation and our subsequent idea. The visible notion of a mountain evidently contains feeUngs of \isual movement. But, when we look at a circle, — say, one-tenth of an inch in diameter. — the eye can take in the whole of it without movement, and we might suppose that the sensation is, in that case, purely optical, there being no apparent necessity for introducing the muscular consciousness. A characteristic optical impression is produced ; we should be able to discrimi- nate between the small circle and a square, or an oval ; or between it and a somewhat larger or a somewhat smaller circle, from the mere optical difference of the effect on the retina. Whj' then may we not say, that, through the luminous tracing alone, we have the feeling of visible form? By making an extreme supposition of this nature it is possible to remove 39H RETENTIVENESS— LAW OF CONTIGUITY. tations. The one is, that the mere fact of optical distinctness and plurahty carries with it, as a part of its own nature, the perception of space ; a supposition entirely gratuitous. The second interpretation is, that the author tacitly imphes the Kantian doctrine of space as an a priori form, manifested in consciousness when we have plurahty of optical sensations, as two candle flames. Without dwelling on all the diffi- culties attendant on a. priori forms, we are content here to present the alternative, or a posteriori explanation, which is that space involves, as its very import, locomotive experience, and is made up by a combination of sensations with feelings of movement, actual and possible. If I see two distinct objects before me, as two candle flames, I apprehend them as different objects, and as distant from one another by an interval of space ; but this apprehension presupposes an independent experience and knowledge of lineal extension. There is no evidence to show that, at the first sight of these objects, and before any association is formed between visible appearances and other movements, I should be able to ap- the case frora a direct experimental test. We may still, however, see very strong grounds for maintaining the presence of a muscular element even in this instance. In the first place, our notions of form are manifestly obtained by working on the large scale, or by the survey of objects of such magnitude as to demand the sweep of the eye, in order to comprehend them. We lay the foundations of our knowledge of visible outline in circumstances where the eye must be active, and must mix its own activity with the retinal feelings. The visual idea of a circle is first gained by moving the eye round some circular object of considerable size. Having done this, we transfer the fact of motion to smaller circles, although they would not of themselves demand an extensive ocular sweep. So that, when we look at a little round body, we are already pre-occupied with the double nature of visible form, and are not in a position to say how we should regard it, if that were our first experience of a circle. But, in the second place, as remarked in the text, with regard to Dis- tance and Extension, the essential import of visible form is something not attainable without the experience of moving the eye. If we looked at a little round spot, we should know an optical difference between it and a triangular spot, and we should recognize it as identical with another round spot ; but that is merely retinal knowledge, or optical discrimination. That would not be to recognize form, because by form we never mean so little as a mere change of colour. We mean by a round form something that would take a given sweep of the eye to comprehend it ; and unless we identify the small ESSENTIAL IMPORT OF EXTENSION. 397 prehend in the double appearance a diiference of place. I feel a distinctness of impression, partly optical and partly muscular ; but in order that this distinctness may mean to me a difference of position in space, it must reveal the additional fact, that a certain movement of my arm would carry my hand from the one flame to the other, or that some other movement of mine would change, by a definite amount, the appearance I now see. If no information is conveyed respecting the possibility of movements of the body generally, no idea of space is given ; for, we never consider that we have a notion of space, unless we dis- tinctly recognize this possibility. But how a vision to the eye can reveal beforehand what would be the experience of the hand or the other moving members, has never been explained. The conjoint experience of the senses and the movements appears to me to furnish all that we possess in the notion of Extended matter. The association between sight and loco- motion, or between touch and the movements of the arm, spot with the circles previously seeu, we do not perceive it to be a circle. It may remain in our mind as a purely optical meaning ; but we can never cross the chasm that separates an optical meaning from an effect combining light and movement, in any other way than by bringing in some experience of movement. Professor James has elaborately examined the whole question, bringing to bear upon it original experiments, as well as criticising known facts. This general summary contains the following conclusions : — ' All our sensations are positively and inexplicably extensive wholes. The sensations contributing to s'psice- perception seem exclusively to be the surface of skin, retina and joints. Muscular feelings play no appreciable part in the generation of our feelings of form, direction,' etc. {Psychology, vol. ii. p. 268). As muscular feelings are present during the educative process whereby we attain our space-perceptions, the difficulty is to regard them as merely otiose. If the supposed education were begun and completed in the lifetime of the individual, and if the history of infancy were patent to us at every stage, there might be some chance of our deciding between the opposite \'iews. But, on the other hand, if there be an indefinable hereditary element, it is impossible to obtain access to the stages of the operation. All that remains to us is to give our individual judgments of the composition of the space-perception by comparing it in consciousness with what we may surmise, from the essential meaning, to be the constituent sensations. 898 EETENTIVENESS — LAW OF CONTIGUI.TY. tells US that a given appearance implies the possibility of a certain movement ; that a remote building implies a cer- tain continuance of our walking exertions to change its appear- ance into another that we call a near view : and the power of motion, the scope for moving, exhausts every property in the idea of empty space. We estimate it first by our own movements, and next by other movements measured in the first instance by our own, — as, for example, the flight of a bird, the speed of a cannon ball, or the movement of light. The mental conception that we have of empty Space, is scope for movement, the possibility or potentiality of moving; and this conception we derive from our experience of move- ments. The resistmice to movement is our notion of a Plenum or occupied space ; the eo^tent of movement is our measure of the linear Extension of body or extended Magnitude. No internal revelation, nothing in the nature of intuition or innate suggestion, would seem required for giving us such notions as we actually have of these qualities. In a former section (The Highee Ixstixcts, p. 330), the question was mooted as to the sufficiency of life experiences for consoli- dating the vast acquirement involved in the perception of tri- dimensional space. The conclusion arrived at was, that the pro- cess could not be completed within the compass of our infant education ; and that the accumulated experience of previous generations, hereditarily transmitted, would alone account for the result. This in no way aifects the foregoing contention as to the concurrence of sense and movement in our notions of Externality, Space, etc. The import of these notions remains the same what- ever might be the length of time required for building them up as now possessed by us. For a further discussion of this whole question, see Note G, Perception and Belief of the Material World. 38. Under this head, as now commonly viewed, there are two entirely distinct issues. The one is characterized by the term metaphysics or metaphysical, while the other is a properly psychological question. The metaphysical or THE MATERIAL WORLD. 399 ontological question is, whether or not the so-called outer or external world is a thing existing independent of the perceiving mind. This was the view prevailing among mankind until Berkele}^ averred that it could not be held without self-contradiction. Perception, Knowledge, is a mental act. (1) There is no possible knowledge of a world except in reference to our minds. Knowledge means a state of mind ; the notion of material things is a mental fact. We are incapable even of discussing the existence of an independent material world ; the very act is a contradiction. We can speak only of a world presented to our own minds. By an illusion of language, we fancy that we are capable of con- templating a world that does not enter into our own mental existence ; but the attempt belies itself ; the contemplation is itself an effort of mind. The pros and cons of this thesis constitute a topic of dis- cussion that passes out of the sphere of psychology proper. It makes, in fact, a department of its own, and has occupied many pages of dissertations. It is in contact both with logic and with psychology, but is not exhaustively viewed under either. Most commonly, a reference is made to a supposed intuition or instinct that is above the sphere of questioning or discussion. Whether this be so or not is the principal point for contending parties to deal with.* Proper to psychology, and strictly within its sphere, is the genesis of our notion of externality, considered as a part of our conscious being. While, midway between Meta- physics, as Ontology or Theory of Being, lies Epistemology, or Theory of Knowledge ; dealing with the validity of knowledge, as distinct from genesis on the one hand, and from mere being on the other. (2) Solidity, Extension, and Space, — the foundation pro- perties of the material world, — mean, as has been said already, certain movements and energies of our own body, and exist in our minds in the shape of feelings of Force, * See Mind, vol. vi. 394, vol. xiv. 384, 400 RETEISTTIVENESS — LAW OF CONTIGUITY. allied with visible, and tactile, and other sensible impressions. The sense of the external is the consciousness of particular energies and activities of our own. If we were the subjects of purely passive sensation — such sensations as warmth, odour, light, — apart from any movement of any active member whatever, our recognition of the external world would necessarily be something very different from what we now experience. The state of the consciousness would then, so far as we are able to imagine it, be of the nature of a dream, and our perception of the universe would be sufficiently represented by the common theory of idealism. But, in us, sensation is never wholly passive, and, in general, is much the reverse. Moreover, the tendency to movement exists before the stimulus of sensation ; and movement gives a new character to our whole percipient existence. The putting forth of energy, and the conscious- ness of that energy, are facts totally different in their nature from pure sensation ; meaning thereby sensation without activity, of which we can form some approximate idea, from the extreme instances occurring to us of impressions lan- guidly received. It is in this exercise of Force that we must look for the peculiar feeling of externality of objects, or the distinction that we make between what impresses us from without and impressions not recognized as external. Any impression on the senses that rouses muscular energy, and that varies with that energy, we call an external impression. Dr. Johnson refuted Berkeley, as he thought, by kicking a stone. In fact, this action of Johnson's illustrates the real nature of our recognition of externality. It was his own exertion with its consequences, and not the optical impression of a stone on the eye, that satisfied him as to the existence of something outside of him. The sum total of all the occasions for put- ting forth active energy, or for conceiving this as possible to be put forth, is our external world. Taking the order of the senses followed in our exposition b EXTERNALITY CONNECTED WITH SENSE OF RESISTANCE. 401 in the previous book, Touch is the first that decidedly makes us cognizant of an external world. But if we were confining ourselves to the class of sensations of soft touch, where we have the passive pleasure of the sense in highest perfection, we should not find much superiority in this sense over smell, on the point now under consideration. It is hard contact that suggests externality ; and the reason is, that in this contact we must put forth force of our own. The more intense the pressure, the more energetic the activity called forth by it. This mixed state, produced through reacting upon a sensation of touch b}^ a muscular exertion, constitutes the sense of resist- ance, — the feeling that is the deepest foundation of our notion of externality. ' There is no feeling of our nature of more importance to us than that of resistance. Of all our sensa- tions, it is the most unintermitted; for, whether we sit, or lie, or stand, or walk, still the feeling of resistance is present to us. Everything we touch at the same time resists ; and everything we hear, see, taste, or smell, suggests the idea of something that resists. It is through the medium of resist- ance that every act by which we subject to our use the objects and laws of nature is performed. And of the com- plex states of consciousness, there is hardly one in which the feeling or idea of resistance is not included ' (James Mill). In fact, we constanth* carry about with us the feel- ing or the notion of resisting, — in other words, the state where a sensation of touch is coupled with the putting forth of effort or force. The main consideration, therefore, in this great question is, that the totality of our mental life is made up of two kinds of consciousness — the Object consciousness and the Subject consciousness. The first is our external world, our non-ego ; the second is our ego, or mind proper. It is quite true that the object consciousness, which we call Externality, is still a mode of self in the most comprehensive sense, but not in the usual restricted sense of 'self and 'mind,' which are names for the subject, to the exclusion of the object. (3) We experience certain miiformly recurring sensations, 26 402 EETENTIVENESS — LAW OF CONTIGUITY. and certain uniform changes m these, when we exert parti- cular energies. Thus, the visible picture of our dwelhng is a permanent and habitual experience, and the variations undergone by it correspond principally to our own conscious movements. But, at times, the appearance is entirely withdrawn, and exists only in memory or idea. We then feel the difference between the two experiences — the ideal and the acuial ; and we assign some superiority in the mode of existence of the one over the other. The superiority we soon find to connect itself with the changes due to our movements : a mere picture or idea remains the same what- ever be our bodily position or bodily exertions ; the sensation that we call the actual is entirely at the mercy of our move- ments, shifting in every possible way according to the varieties of action that we go through. With a forward movement, the visible impression enlarges ; with a backward movement, it diminishes. One movement of the eye shuts it off; another movement restores it. The carriage of the head alters it from side to side ; the bending of the body varies it in other ways. We are constrained to make a dis- tinction between the things that are thus shifted by all our movements, and the ideas or dreams that vary of themselves while we are still. Even if sensation meant nothing apart from ourselves, we should still have to distinguish between present sensation and remembered or revived sensation ; the reference of the one to our voluntary movements, and of the other to no such modifying causes, would oblige us to note a vital difference in the two classes of facts. Such is the uniformity of connexion between certain appearances and certain movements, that we come to anticipate the one through the other. We know that, in some one position, as when lying in bed, a movement of the limbs will bring us to the sensation of a solid contact in the feet ; that another series of movements will bring on a particular view to the sight ; that a third movement will bring the sound of a bell to the ear, and so forth. We recognize all those sen- sible effects, thus brought uniformly into play by a regular SENSATIONS VARY WITH DEFINITE ENERGIES. 403 series of waking voluntary actions, as totally different from onr ideas, recollections, and dreams. (4) As our belief in the externalit}^ of causes of our sensations means that certain actions of ours will bring the sensations into play, or modify them in a known manner, this belief is easily furnished to us by experience ; it is no more than our experience entitles us to entertain. Having felt again and again that a tree becomes larger to the eye as we move ; that this movement brings on at last a sensation of touch ; that this sensation of touch varies with move- ments of our arm, and a great many other similar coin- cidences ; the repetition of all this experience fixes it in the mind, and, from the sight alone, we can anticipate all the rest. We then know that our movements will bring about all the changes and sensations above described, and we know no more ; but this knowledge is to us the recognition of external existence, — the only thing, so far as I see, that external existence can possibly mean. Belief in external reality is the anticipation of a given effect to a given ante- cedent ; and the effects and antecedents are our own various sensations and movements. (5) A\T^ien we find that one fixed set of movements brings on at the same time sensations of various senses, — as when approaching an orchard we have sights and sounds and touches and sinells and tastes, — the fact very much enhances the notion we have of the dejjendence of sense on action or movement, the richness, so to speak, of the external world, the value of our action as bringing on sensation. Moreover, when successive movements bring forward endless varieties of new sensations, we are in this way also impressed with the abundance of effect brought on as a consequence of oiu* own movement. We see the largeness of the possible world as compared with the appearance that self makes — the expanse of our own body, — which is to us a constant unit of comparison and standard of reference. A\Tiether the causes of appearances are external to our mind or not, we are at all events certain that they are external to our bodies ; for between the world 404 RETENTIVENESS — LAW OF CONTIGUITY. and each one's corporeal presence a comparison is possible ; while between the world and mind there is no comparison, the things not being homogeneous. We incur the absurdity of converting mind into a substance to be viewed by another mind, when we speak of our perceiving faculty as an ex- tended thing. But a world extending beyond our own person we can understand ; it implies that the movement that traverses the body must be many times multiplied to traverse the world — that is, to bring forward the whole array of possible changes of sensation. (6) When we come to communicate with other beings, and discover by the signs of communication that they pass through the same experience as ourselves, this enhances still more the constancy of the association between our sensations and the corresponding active energies. We ascertain that, at times when we ourselves are not affected by a particular sensation, as of light, other persons are affected by it. This leads us to generalize sensation still more, and to form to ourselves an abstraction that comprehends all our experience, past and present, and all the experience of others ; which abstraction is the utmost that our minds can attain to respecting an external and material world. So often as I open my eyes, I have the sensation of light (the exceptions are not material to the illustration). I thereupon associate this sensation with this action, and I expect, in all future time, that the action will lead to the sensation. Other persons tell me it is the same with them. I thereupon affirm, as a general fact, that an optical feeling will always follow a certain muscular feeling, to me and to other sentient beings ; and I can affirm nothing more, nor can I have any possible interest or concern with anything more. The assertion that light and the sun have a permanent and independent existence has, for its basis and for its import, that I and all other beings with whom I have had any communication, have had a certain optical feeling in conjunction with certain activities of which we have been conscious, and firmly anticipate the same coinci- dence in the future. The external existence of a stone wall THE EXTERNAL IS THE COMMON TO ALL. 405 means the association between certain optical impressions and a particular locomotive effort, and a further and still more decided association between touch and another effort, — namely, what we call the sense of resistance. Finding the same sequence to exist with reference to beings in general, we generalize the fact to the very farthest limits, and affirm that it has always been so in the past, and will always be so in the future. Our language is apt to go beyond this. Out of all the particular experiences (which alone constitute the real evidence for the proposition) , we construct an experience in the abstract, — a pure fiction, — that goes the length of affirm- ing that the sensation is not only sure to occur along with the appropriate actions, but that it exists whether these actions take place or not. We seem to have no better way of assuring ourselves and all mankind that, with the con- scious movement of opening the eyes, there will always be a consciousness of light, than by saying that the light exists as an independent fact, with or without any eyes to see it.* 39. Related facts in Visual Perception. — In visual perception, there stand out four distinct facts, — namely, Ocular Adjust- ment for seeing an object, the Extent of the image on the Retina, the Distance, and the true Magnitude of the object. We find that, in the educated eye, these circumstances are suggestive of one another. On this subject, I shall avail myself (as in former editions), of the observations of Sir Charles Wheatstone, in his Bakerian Lecture, contained in the Pliilosophical Transactions for 1852. The question to be solved is, — How do we come to connect a certain felt effect on the eye, with a knowledge of the distance and size of the object causing the impression; as when we say that a lamp-post is twenty feet off, or that a distant wood is within three or four miles '? When the gaze is still, the optical impression implies no more than these two facts, — a certain effect of light and colour, and an adjustment of * For a more minute analysis of the distinction of subject and object, see The Emotions and the Will, p. 574. 406 RBTENTIVENESS — LAW OF CONTIGUITY. the eyes singl}^ and conjointly ; when the gaze is wandering, the movements and changes of adjustment operate in addi- tion. I quote as follows : — ' Qnder the ordinary conditions of vision, when an object is placed at a certain distance before the eyes, several concurring circumstances remain constant, and they always vary in the same order when the distance of the object is changed. Thus, as we approach the object, or as it is brought nearer to us, the magnitude of the picture on the retina increases ; the inclination of the optic axes required to cause the pictures to fall on corre- sponding places of the retinae, becomes greater ; the divergence of the rays of light proceeding from each point of the object, and which determines the adaptation of the eyes to distinct vision of that point, increases ; and the dissimilarity of the two pictures projected on the retinae also becomes greater. It is important to ascertain in what manner our perception of the magnitude and distance of objects depends on these various circumstances, and to inquire which are the most, and which the least, influential in the judgments we form. To advance this inquiry beyond the point to which it has hitherto been brought, it is not sufficient to content ourselves with drawing conclusions from observations on the circumstances under which vision naturally occurs, as preceding writers on this subject mostly have done, but it is necessary to have more extended recourse to the methods so successfully employed in experimental philosophy, and to endea- vour, wherever it be possible, not only to analyze the elements of vision, but also to re-combine them in unusual manners, so that they may be associated under circumstances that never naturally occur ' (p. 2). Accordingly, Sir C. Wheatstone devised an instrument, being a modification of his reflecting stereoscope, whereby he exposed pictures to the two eyes in such a manner that the Distance could be changed while the Convergence of the two eyes remained the same, or the Convergence be altered while the Distance re- mained the same ; thus disassociating two effects that constantly go together in ordinary vision. The result of the experiments showed the influenceof each of the two circumstances, — namely, the Convergence of the eyes and the Size of the picture on the retina (which is greater as the object is nearer), in determining our VISUAL PERCEPTION OF REAL MAGNITUDE. 407 judgment of Distance. He found that, the distance of the object remaining the same, the greater convergence of the two eyes makes the object seem smaller, this increased convergence being required in ordinary vision when a thing is brought nearer. It appears, therefore, that, while the retinal magnitude is unaltered, greater convergence gives a perception of smaller Size. On the other hand, leaving the inclination of the axes unchanged, and bringing the pictures nearer, thereby increasing the picture on the retina, "we have a perception of increased Size in the object. ' The perceived magnitude of an object, therefore, diminishes as the inclination of the axes becomes greater, while the distance remains the same ; and it increases when the inclination of the axes remains the same, while the distance diminishes. When both these conditions vary inversely, as they do in ordinary vision when the distance of an object changes, the perceived magnitude remains the same.' Thus, as regards the perception or appreciation of the real magnitudes of objects seen by the eye, the association lies be- tween a certain magnitude (ascertained by other means than sight j, and a certain inclination of the optic axes with a given size of the picture on the retina. The figure of a man, of which we have a certain muscular estimate by our movements and previous experience, when view^ed at some one inclination of the optic axes, yields an image on the retina of a particular size; and with such inclination and size of image we then associate the muscular appreciation of an object six feet high, etc. The concurrence of these tw^o conditions always suggests a similar magnitude or extent of the thing viewed. And if the optic in- clination is made smaller, — that is, if the axes of the eyes approach more to parallelism, - while at the same time the image on the rebina is correspondingly less, as by removing the object to a greater distance, there will still be a perception of the same size, or the same muscular appreciation will be suggested to the mmd. We have an association of the size of a man with a great many different combinations of those two circumstances, produced by variation of actual distance. 40. Next, as respects our perception and estimate of dis- tance, or the suggestion of a given locomotive exertion with a visual appearance. On this head. Sir C. Wheatstone's obser- 408 EETENTIVEXESS — LAW OF CONTIGUITY. vations have still distinctive value. He considers that the appreciation of distance, instead of preceding the esthnate of magnitude, folloivs it. 'It is the prevalent opinion that the sensation which accompanies the inclination of the optic axes immediately suggests distance, and that the perceived mag- nitude of an object is a judgment arising from our consciousness of its distance, and of the magnitude of its picture on the retina. From the experiments I have brought forward, it rather appears to me that what the sensation which is connected with the con- vergences of the axes immediately suggests, is a correction of the retinal magnitude to make it agree with the real magnitude of the object, and that distance, instead of being a simple percep- tion, is a judgment arising from a comparison of the retinal and perceived magnitudes. However this may be, unless other signs accompany the sensation of convergence, the notion of distance we thence derive is uncertain and obscure ; whereas the percep- tion of the change of magnitude it occasions is obvious and unmistakable.' According to this view, distance is more firmly associated with the retinal magnitude than with the other cir- cumstances of optical inclination. When we view an object receding, as a carriage, we are impressed with the change of distance more through the diminishing size of the picture it makes on the retina, than through the approach of the optic axes to parallelism. I am not at all surprised at this, seeing that the change in the size of the retinal picture is so much more evident and distinct, as a sensation, than the very slight corresponding alteration in the inclination of the axes. When we once ascer- tain the real magnitude of a body, the approaching or receding of it is very easily measured from this change of the picture. Now, according to Sir C. Wheatstone, the inclination of the axes, in comixuuj tcith a given retinal picture, suggests the magnitude first, mid from the true magnitude thus hiown, and the retinal magni- tude, toe infer the distance* This, it may be remarked, is the * When a known object is magnified by a lens, we suppose it brought nearer to us, owing to this increase of retinal magnitude while the convergence remains the same. I have not specially adverted in the text to the signs of distance furnished by the colour and appearance of objects. This point has been well illustrated by Dr. Reid [Inquiry, chap. vi. sect. 22). I quote the following paragi-aphs :— ' The colours of objects, according as they are more distant, become more PERCEPTION OF SOLIDITY. 409 strongest possible proof of our former thesis, that the perception of Distance is acquired. 41. Passing now to the perception of solidity, or solid effect, on which the discovery of the stereoscope has cast a new light, by connecting that effect with the action of the two eyes, I find that Sir C. Wheatstone, in his published paper, considered this as still imperfectly explained. I have faint and languid, and are tinged more with the azure of the intervening atmosphere : to this we may add, that their minute parts become more indistinct, and their outline less accurately defined. It is by these means chiefly, that painters can represent objects at very different distances, upon the same canvas. And the diminution of the magnitude of an object would not have the effect of making it appear to be at a great distance, without this degradation of colour, and indistinctness of the outline, and of the minute parts. If a painter should make a human figure ten times less than other human figures that are in the same piece, having the colours as bright, and the outline and minute parts as accurately defined, it would not have the appearance of a man at a great distance, but of a pigmy or Lilliputian. ' When an object hath a known variety of colours, its distance is more clearly indicated by the gradual dilution of the colours into one another, than when it is of one uniform colour. In the steeple which stands before me at a small distance, the joinings of the stones are clearly perceptible ; the grey colour of the stone, and the white cement are distinctly hmited : when I see it at a greater distance, the joinings -of the stones are less distinct, and the colours of the stone and of the cement begin to dilute into one another : at a distance still greater, the joinings disappear altogether, and the variety of colour vanishes. 'In an apple tree which stands at the distance of about twelve feet, covered with flowers, I can perceive the figure and the colour of the leaves and petals ; pieces of branches, some larger, others smaller, peeping through the intervals of the leaves— some of them enlightened by the sun's rays, others shaded ; and some openings of the sky are perceived through the whole. When I gradually remove from this tree, the appearance, even as to colour, changes every minute. First, the smaller parts, then the larger, are gradually confomided and mixed. The colours of leaves, petals, branches, and sky, are gradually diluted into each other, and the colour of the whole becomes more and more uniform. This change of appearance, corresponding to the several distances, marks the distance more exactly than if the whole object had been one of colour. ' Dr. Smith, in his " Optics," gives us a very curious observation made by Bishop Berkeley, in his travels through Italy and Sicily. He observed. That, in those countries, cities and palaces seen at a great distance appeared nearer to him by several miles than they really were: and he very judiciously 410 RBTENTIVENESS — LAW OF CONTIGUITY. reason to believe, however, that, havino- made many experi- ments with the view of elucidating the point, he inclined to the view that there is a mental effect ■prodiiced over and above the optical effect ; which mental effect overrides the optical im- pression, and gives a perception really different from the literal sensation. The sense of solidity, arising from the imputed it to this cause, That the purity of the Italian and Sicilian air, gave to very distant objects that degree of brightness and distinctness which, in the grosser air of his own country, was to be seen only in those that are near. The purity of the Italian air hath been assigned as the reason why the Italian painters commonly gave a more lively colour to the sky than the Flemish. Ought they not, for the same reason, to give less degradation of the colours, and less indistinctness of the minute parts, in the representation of very distant objects ? ' It is very certain that, as in air uncommonly pure, we are apt to think visible objects nearer and less than they really are, so, in air uncommonly foggy, we are apt to think them more distant and larger than the truth. Walking by the sea-side in a thick fog, I see an object which seems to me to be a man on horseback, and at the distance of about half a mile. My com- panion, who has better eyes, or is more accustomed to see such objects in such circumstances, assures me that it is a sea-gull, and not a man ou horseback. Upon a second view, I immediately assent to his opinion ; and now it appears to me to be a sea-gull, and at the distance only of seventy or eighty yards. Tlie mistake made on this occasion, and the correction of it, are both so sudden, that we are at a loss whether to call them by the name otjudgiucnt, or by that of simple perception. ' It is not worth while to dispute about names ; but it is evident that my belief, both first and last, was produced rather by signs than by arguments, and that the mind proceeded to the conclusion in both cases by habit, and not by ratiocination. And the process of the mind seems to have been this — ■ First, Not knowing, or not minding, the effect of a foggy air on the visible appearance of objects, the object seems to n\e to have that degradation of colour, and that indistinctness of tlie outline, which objects have at the distance of half a mile ; therefore, from the visible appearance as a sign, I iiiuiiediately proceed to the belief that the object is half a mile distant. Then, this distance, together with the visible magnitude, signify to me the real magnitude, which, supposing the distance to be half a mile, must be equal to that of a man on horseback ; and the figure, considering the in- distinctness of the outline, agrees with that of a man on horseback. Thus the deception is brought about. But when I am assured that it is a sea-gull, the real magnitude of a sea-gull, together with the visible magni- tude presented to the eye, immediately suggest the distance, which, in this case, cannot be above seventy or eighty yards : the indistinctness of the figure likewise suggests the fogginess of the air as its cause ; and now the SIGNS OF DISTANCE FROM VARYING APPEARANCES. 411 conjoined action of two dissimilar views of an object pre- sented to the two eyes, means a suggestion to the mind that one part of the object is farther off than another, as esti- mated by our locomotive organs ; in other words, the impression revives in us an idea of movement to or from the eye in company with the picture. When the two eyes view whole chain of signs, and things signified, seems stronger and better connected than it was before ; the half-mile vanishes to eighty yards ; the man on horseback dwindles to a sea-gull ; I get a new perception, and wonder how I got the former, or what is become of it ; for it is now so entirely gone, that I cannot recover it. ' It ought to be observed that, in order to produce such deceptions from the clearness or fogginess of the air, it naust be uncommonly clear or uncom- monly foggy; for we learn, fi-om experience, to make allowance for that variety of constitutions of the air which we have been accustomed to observe, and of which we are aware. Bishop Berkeley therefore committed a mistake, when he attributed the large appearance of the horizontal moon to the faint- ness of her light, occasioned by its passing through a larger tract of atmos- phere : for we are so much accustomed to see the moon in all degrees of faiutness and brightness, from the greatest to the least, that we learn to make allowance for it ; and do not imagine her magnitude increased by the faiutness of her appearance. Besides, it is certain that the horizontal moon seen through a tube which cuts off the view of the interjacent ground, and of all terrestrial objects, loses all that unusual appearance of magnitude.' The following paragraphs illustrate the effect of intcrccnin;/ objects in aiding our perception of Distance. ' We frequently perceive the distance of objects, by means of intervening or contiguous objects, whose distance or magnitude is likewise known. When I perceive certain fields or tracts of ground to lie between me and an object, it is evident that these may become signs of its distance. And although we have no information of the dimensions of such fields or tracts, yet their similitude to others which we know suggests their dimensions. • We are so much accustomed to measure with our eye the ground which we travel, and to compare the judgment of distances formed by sight, with our experience or information, that we learn by degrees, in this way, to form a more accurate judgment of the distance of terrestrial objects, than we could do by any of the means before mentioned. An object placed on the top of a high building, appeal's much less than when placed upon the ground, at the same distance. When its stands upon the ground, the intervening tract of ground serves as a sign of its distance : and the distance, together with the visible magnitude, serves as a sign of its real magnitude. But when the object is placed on high, this sign of its distance is taken away, the remaining signs lead us to place it at a less distance, and this less distance, together with the visible magnitude, becomes a sign of a less real magnitude.' 412 EETENTIVENESS — LAW OF CONTIGUITY. the perspective of a street, there is brought up the idea of a certain amount of walking exertion, or other locomotive measurement, as part of the perception thence arising. The two eyes looking at a footstool bring up, in like manner, ideas of greater or less remoteness of the parts. Now, the diffi- culty lies in explaining ' why two dissimilar pictures projected on the two retinae, give rise to the perception of an object in relief. 'It may be supposed,' says Wheatstone, 'that we see but one portion of a field of view at the same instant, the one, namely, to which the optic axes are directed, while all other points are seen so indistinctly that the mind does not recognize them to be either single or double, and that the figure is appreciated by directing the point of convergence of the optic axes successively to a sufficient number of its points to enable us to judge accurately of its form.' But observation does not confirm this supposed indistinctness of those parts for which the eyes are not adjusted. On looking at a stereoscopic view, for example, we find that we obtain a clear and distinct picture of the whole, even when the eyes are steadily fixed upon one point, during which act, by the supposition, all points nearer or farther ought to be confusedly and imperfectly perceived. Hence it is that Sir C. Wheatstone was led to adopt the foregoing view of a mental suggestion coming in to present a clear and perfectly formed idea, notwithstanding the optical fact that, for many parts of the view, there actually falls upon the eyes what would be a double and indistinct image. When the mind is once accustomed to fully formed views of all kinds, these are revived by the force of association, the main circumstance for determining the view being present — namely, the double aspect which our experience has always connected with a solid effect, or an effect where varying distance is conjoined with lateral extension.* This hypo- * Binocular Vision has been extensively studied since Wheatstone's time in Germany, in America, and at home. Volljmann held that the unity of the picture is arrived at by the mind disregarding the conflicting parts of the two pictures, and attending only to their points of agreement. To him, BINOCULAR VISION. 413 thesis appeals to what is uiidoubtedlj^ a vera causa in the region of mind. 42. Into this matter, however, I do not enter further the dissimilarity is an encumbrance to be shaken off, an obstacle to be sur- mounted. Wuudt, on the other hand, holds that the dissimilarity, far from being an obstruction, is the very instrument or medium of our notion of solidity. It is (after variation of retinal magnitude) the most suggestive of all the optical marks of a third dimension. The more pronounced the dissimilarity, the more emphatic is our sense of solidity and varying distance from the eye. In the remarks on Double Vision under the Sense of Sight, I have pro- ceeded upon this latter view as best supported by evidence. In the theory of Volkmann, there appears a needless anxiety on the subject of the double picture, as if it would necessarily distract us with two differing representa- tions of one object. It is fancied that each eye presents a complete image in itself, and that the mind must reconcile these two separate images, before attaining the desired unity of perception. But there seems to be a misappre- hension in so regarding the question. Each eye does not present the complete picture, but only a part of the picture ; the other eye taking in the other part. We might have a body so placed to the two eyes, that the one eye should ap- prehend one side and the other eye the other side ; in which case, the double impression is obviously the picture. Experience tells us that an occasion like this — where both eyes must concur to give the whole extent of the picture, or where we see more by the two than by the one — involves a retreating object, or the solid effect. It is no more necessary that the two eyes should give two complete and separate pictures to the mind, than that the two hands, embracing the same ball, should suggest two balls ; or that the thumb and finger grasping a pen should suggest two pens. The eyes are formed to aid and supplement, and not to contradict each other. In great distances, each eye is sufficient for taking in the view ; no addition is made by their con- joint action. This circumstance is to us simply a token of a far prospect. The opposite case, where the two pictures have nothing in common, is inter- preted as the extreme of nearness in the object. It may be the fact, that one eye takes the lead in vision, the other merely coming in to supply the additions that constitute solid effect ; just as ia feeling anything, we use chiefly the right hand (or the left), and attend to its indications, while the other merely corrects or adds to the notion. Our \isual ideas would thus be embodied in the sensation of one eye, while the other, making no claim, in the same individual, to have its sensation em- bodied separately, gives that extension of view and those adjuncts that serve in the full solid effect. Dr. Carpenter has made this remark, with reference to the binocular microscope. The observer uses one eye principally, and, for that eye, it is desirable that the instrument should be as perfect as possible ; the other eye has no further use than to bring out the stereoscopic or tri- dimensional effect (see Sight, p. 241). 414 EETENTIVEXESS — LAW OF CONTIGUITY. than to remark, that the same circmnstances that enable us to appreciate the distances of different objects, enable us also to appreciate solid effect, or the continuity of an object throuojh varpng distances. The definite change in the inclination of the axes, concurring with a definite and proportional change of the retinal magnitude (the tendency to parallelism of the axes accompanpng a decrease of retinal magnitude), would suggest the real width of a street to be the same all through ; upon which, the diminished picture gives assurance of the increasing remoteness of the successive parts. A question has been raised as to our mode of perceiving the direction of an object from the eye. On this, I would still repeat that direction is not a perception of sight alone ; its very meaning precludes the supposition. It implies the locomotive or other movement that would lead us up to the object, or produce a definite change in its appearance. But there is a certain optical effect constantly associated ^dth the sense of direction, as there is with the sense of magni- tude or of distance ; and this effect it is interesting, as a matter of fact, to ascertain. Xow, it appears most probable that the line of visible direction is a line passing from the place of an object's impression on the retina through the centre of the crystalline lens : * hence, we associate an effect on the centre of the retina with a direction in the line of the axis of the eye, while an impression to the right of this point would suggest a position left of the axis. But, without the experience of our moving organs generally, we should never know, either the meaning of direction, or the fact that a certain impression of the retina implied a certain course for us to take in reference to the object. If the optical law had been entirely different — if, for example, an object were to lie in a direction inclined 45° to the plane of its image in the retina, — we should equally well become acquainted with * This line has been variously stated. Sir David Brewster affirms that it passes through the centre of the eye (see p. 216 of a work entitled, Essai surles Phosphenes, etc., par Ic Dr. Serre, Paris, 185-3). DIRECTION OF AN OBJECT FROM THE EYE. 415 direction : experience would comiect the locomotive estimate with the Tisual impression as completely as is done now. The question is very much of the same nature as that of inverted vision, formerly discussed : it matters not where or how the optical effect takes place ; association connects the true perception with it. In fact, when we dress by a mirror we perform a series of inversions, very difficult at first, but in the end as easy as working under direct vision. Localization of Bodily Feelings. 43. The localization of our bodily feehngs presents an interesting case of acquired perception. Previous to ex- perience, we have no notion of the seat of any local sensa- tion, — for example, a pain in the shoulder or the toe. It seems impossible we should have such a notion intuitively, inasmuch as we must connect an internal feeling with a picture to the eye, or an estimate to the touch, of the part where the feeling arises. Our own body is a thing exposed to all our senses, and to the sweep of our movements, like a table, or a statue, or a fowling-piece. The eye can scan nearly the whole of it ; the hand can sweep over it ; the legs can move over parts of it ; the ear can hear the somids it makes ; the ' mouth and tongue can co-operate with the hand. The eyes can appreci- ate the colour, outline, and solidity ; the mind, accustomed to the perception of size and distance, can form an estimate of the remoteness of the parts and the magnitude of the whole, — the body's own various movements concurring in the estimate. So far, the body is to us an external object ; but it is also the seat of sensibility of various kinds, which sensibility we can usually refer to some locality — as the head, arms, chest, etc. The question arises. How do we come to have this knowledge of locality ? I answer. By experience and associa- tion, based on the distinctness of the nerve fibres supplied to the different parts (see Touch, p. 190). A pinch in the toe is not sensibly different in quality from a pinch in the 416 RETENTIVENESS — LAW OF CONTIGUITY. finger ; but, if both were happening together, we should have a sensation of two actions, and not of a single action made stronger. This is owing to the distinctness of the nerves ; and, through this distinctness, we can form separate associa- tions with each. I can associate one pain with the sight of my finger, another pain with the sight of my toe, and a third with the position of my arm that leads to the crown of the head. An infant at the outset knows not where to look for the cause of an irritation, when anything touches it ; in time, it notes a coincidence between a feeling and a pressure operating on some one part ; whence, a feeling in the hand is associated with the sight of the hand, and so for otlier members. When the feeling is more internal, as in the interior of the trunk, we have greater difficulty in tracing the precise seat ; often, we are quite at a loss on the point. In such a case, we have to trust to some indications that come to the surface, or to the effect of superficial pressure on the deep parts. On receiving a hurt on the ribs, we learn to connect feelings in the chest with the place on our map of the body : we can thus make experiments on the deap-seated organs, and learn the meaning of their indications. But the more inaccessible the parts, the more uncertainty is there in assign- ing the locality of their sensations ; if, in addition, they are not well supplied with distinctive nerves, the difficulty is still greater. The liver, the spleen, and the kidneys, are indistinct as regards the feelings connected with them. In those places on the skin where the sentient units of nerve are wide apart, — as in the back, the calf of the leg, etc., — we can never acquire a minute appreciation of locality ; the limit of distinctness of the nerve fibres will be the limit of the acquired percep- tion. Foster, in discussing the education of Touch so as to make us susceptible to finer dilferences, expresses himself as follows, on the character of the nerve change that goes along with the im- provement : ' The improvement by exercise of the sense of touch must be explained not by an increased development of the ter- ASSOCIATED DIFFERENCES IX SENSATIONS. 417 minal organs, not by a growth of new nerve fibres in the skin, but by a more exact limitation of the sensational areas in the train, as, for example, by the development of a resistance which limits the radiation taking place from the centres of the several areas '. This association between an internal feeling and the sight or touch of the place where it originates, acts reciprocally, and produces singular effects. Fixing the eye on a part of the body, as the hand, and intently regarding it for some time, we can actually generate a sensation in the skin, by a sort of back current : the idea, — which I conceive to be a past experi- ence, revived on the same nervous tracks, — has a tendency to induce the reality. In the artificial sleep known as the mesmeric state, this influence has been carried to great lengths. Mr. Braid employed it to induce healthy actions upon diseased organs, being able also to cause the opposite effect of inducing unhealthy changes. The power of subjectivity to induce states of disease, on the one hand, and states of health, on the other, is a large and important topic, and has been extensively studied, although without decisive results. The most unambiguous facts are those relating to the production of disease and debility by excessive self-attention ; with the obverse fact of healthy stimulus through the operation of outw'ard or objective regards (see note E). Associated differences in Sensations. 44. We have seen that discrimination is the funda- mental property of the intellect, and that, in so far as we can note differences in our sensations, to that extent these may be called intellectual. Even in Pleasure and in Pain, the nice discrimination of more or less, or of one kind as com- pared with another kind, is so far intellectual. If one person is sensitive to a small difference in pleasurable or painful sensibility, such as would be unfelt by another per- son, the one may be said to be superior to the other intellectually. Discrimination is the groundwork of all knowledge ; for, to know things is to be impressed with their respective characteristic sensations or impressions. We 27 418 EETEXTIVENESS— LAW OF CONTIGUITY. should not know any human bemgs, if they all impressed us alike. A botanist sees in a meadow twenty species of grasses ; an ordinary person has perhaps remarked three or four. As discrimination extends, knowledge and all its consequences extend also. There is an important class of sensations that in them- selves, or as originally felt, are precisely identical, but. by taking on different associations, become as distinct to the mind as sweet and sour in taste, acute and grave in sound, or. red and green in colour. In the sense of Touch, for example, consider the two hands. If we compare the feel- ing of touch ill the right hand with the same kind of contact in the left, we find that they are, as feelings, seemingly identical. But, for intellectual purposes, they become quite distinct ; they can sustain totally different associations. AVith a touch upon my left hand, I associate a w'hole field of imagery seen on my left side ; and with a touch on my right hand, I associate another set of imagery in connexion with my right side. If a person pinches my right hand, I incline my head and direct my eyes to the right ; if my left hand is pinched in precisely the same manner, my movements are all towards the left. The feelings seem identical in every- thing but association. This possibility of suspending differ- ent associations proves that there is some kind of difference in the sensations, that they are not confounded in the brain, though we may not trace this difference in the immediate consciousness. Association alone brings it out.* * Oui" power of localizing our feelings of Touch and Sight has been ex- plained differently. It is maintained in Germany by Lotze, Wundt, and others, upon the evidence of experiments, that the tactile sensations of the two hands, and of the skin everywhere, are qualitatively different, and that this difference of quaUty assists us greatly in leai'ning to discriminate the several localities. To obviate the objection, from our not habitually recognizing any qualitative distinction in the touches in different parts of the body, it is remarked, no doubt with justice, that we are so much concerned habitually with the objective perceptions, as no longer to attend to the subjective differences. These differences may, nevertheless, at an early stage, have been sufficiently marked to form the basis of our local discriminations. In the case of Touch, the supporters of this doctrine find some difficulty ASSOCIATED DIFFEEEXCES IN MUSCULAR FEELIXGS. 419 45. The very same line of illustration can be followed with the muscular feelings as with the forementioned sensations. The feeling of a muscle under contraction has a uniform character all over the body, the degree of tension and all other circumstances being equal. Not to insist on the case of the two arms, or the two legs, or the rotation of the body in opposite ways, which would be similar to the foregoing illustration from touch, we can in stating what is the kind of quality whose variation is perceptible over the body generally. But, in Sight, there is no such difficulty. It is laid down, on the testimony of experiment, that the sensibility of the eye is locally different to colour ; for, if we cause the same colour to pass from the yellow spot to the distant parts of the retina, it will appear, not the same, but different ; and the variation of shade would thus be a mark of the place in the retina where the impression falls. We have here something definite to proceed upon. We can institute an inquiry, as to whether the discrimination of difference of shades of colour is sufficiently delicate, to correspond with the minuteness of vision formei'ly described. Some difficulty might be experienced, under such an hypothesis, in explaining how we should distinguish between an actual succession of colours and the same colour passing over different fibres. I do not say that this is an insuperable obstacle, if it could be shown that our ability to distinguish nice gradations of colour is such as to approach the observed limits of fineness of vision. Between the centre of the yellow sj)ot, and a point in the retina, say 10^ removed from it, we should require to interpolate, at the very least, several hundreds of shades of redness passing into green or blue. I am not prepared to affirm that this is impossible to the primitive eye ; but it is hardly consistent with our ordinary estimate of the powers of the eye, even in persons educated to the discrimination of colours. Still, the hypo- thesis is on« that deserves to be entertained ; it is in some respects, perhaps, less difficult than the assumption of a sense of difference in feelings qualita- tively identical, an assumption supported only by its being adequate to account for the facts of local discrimination. The supposition of latent qualitative differences, where to the common apprehension there is nothing but sameness, must, it would seem, be likewise extended to the muscles. It would have to be shown that there is some- thing distinct in the muscular feelings of the two arms exerted exactly in the same way. When muscles are of very different magnitude and calibre, as the deltoid of the shoulder, the biceps of the arm, the diaphragm, and the orbicular muscle of the mouth, I can readily suppose that we should be differently affected by their contraction ; the difficulty consists in assigning a characteristic peculiai'ity in ^the feeling of expended energy in two muscles in all respects resembling, — as in those of the two sides of the body, — and in others almost identical in size and in form. 420 EETENTIVENESS — LAW OF CONTIGUITY. suppose a weight borne by the arm to give the same amount of muscular feehng as a pressure exerted by the foot. Under this supposition, two feelings are produced that have no dillerence, either as regards feeling, or as stimulating volition; yet, experience shows that they are recognized as distinct by the mind. The two muscular tensions are made manifest to the consciousness by different nerves ; and, on this fact, the mind is able to build and maintain distinct associations, although not aware of any difference, either of quantity or of quality, in the feelings as such. We have already called attention to the articulate character of the sense of Touch, arising from the independence of the nerves of the skin, as distributed over the general surface. This remark is applic- able, also, to the nerves supplied to the different muscles. The same kind of feeling, coming from different parts, is recognized as different by taking on different associations. Before any associations are formed, the difference is latent ; after the growth of distinctive connexions, it is unmistakable. The localizing of our feelings — the possibility of assigning a locality to each — is founded on this distinctness of the nerves arising from different parts. If a prick in the leg and a prick in the arm were as undistinguishable in every way as they are to the mere sense of pain, we should never be able to connect the one with our notion of the leg, and the other with our notion of the arm, or with any of the other distinctive attributes of those two members. If not superfluous, after these examples, the Eye might be adduced to the same effect. The place of the retina impinged upon by a ray of light, is, in the main, unimportant as respects the feeling of light ; but there is, notwithstanding, a real difference in the intellectual point of view, brought out, as in the other cases, by association. We can thus dis- criminate right and left, up and down, centre and circum- ference, in our field of view, as soon as any characteristic actions, or consequences, become connected with the different portions of the retina impinged upon from these various outward positions of the rays of light. The retina is, in this ACQUIRED DISCRIMINATION. 421 respect, identical with the skin : it consists of a number of independent nerve fibres, each transmitting the same quahty of impression (unless the theory of qualitative differences can be established), but to a distinct region of the common centre of visual impressions, and so as to form the starting-point of a perfectly distinct series of accompanying impressions. A man at a telegraphic station, under the old system of signals, saw the same arm repeated to his view ; but, with its picture on the lower part of the retina he connected one action, on the upper part another action. This is associated discrimination. A large and important field of our education is expres- sible under the title of Acquired Difference or Discrimination. This takes on two distinct forms ; the first consists in improv- ing the delicacy of the several senses, which is one of the results of practice or experience, and can occur in all the senses within ascertainable limits It is, no doubt, a consequence of the plastic power of the inind. It is simply the coercing of the attention upon the special effects of sense,— as in en- deavouring to detect a particular shade that we are made aware of by other persons, but do not originally feel in our- selves (see note D). The other form of acquired discrimination covers a very wide field of professional skill and education. It grows out of our accumulated experience of adjuncts and surroundings, calculated to make a much deeper distinction than appears to the eye of sense. A forged bank note may impose upon ordinary vision ; its detection by a banker turns upon nice peculiarities which have been specially impressed upon his mind. The discrimination of diseases, superficially alike in symptoms, rests upon associations stored up in the phy- sician's experience. There is no speciality in the education required ; it is sufiiciently expressed by the ordinary work- ings of contiguity in accumulating technical conjunctions. * * Sir JFillUuii Hamilton's theory of the inverse relation betireen Sensation and Pereeption. This theory has been stated by its author as follows : — ' Though a perception he only possible under condition of. a sensation ; still, 422 EETENTIVENESS — LAW OF CONTIGUITY. ASSOCIATES WITH FEELING. 46. The element of Feeling, or pleasure and pam, viewed as such, enters into alliance with the more intellectual states of mind, — as, for example, those neutral perceptions of outward things that we have just been considering. This alliance or association between feeling and imagery above a certain limit the more intense the sensation or subjective consciousness, the more indistinct tJie perception or objective consciousness ' . By the ' sensation ' is here meant the feeling, as regards pleasure or pain ; by the ' perception ' I understand what is termed above the intellectual discrimination : the dijSer- ence is like that between the excitement of a blaze of sunshine and the discrimination of two natural history specimens. These two effects Sir William Hamilton believes to be inverse to one another ; that is, in propor- tion as the one is strong the other is weak. I am disposed to admit the truth of this doctrine to a very considerable extent. But it appears to me that the facts as to the relation of these two qualities — the emotional, on the one hand, and the intellectual, on the other — show a greater degree of complexity than this law expresses, even although it be correct as to the prevailing character of the relation. The following extract contains the statement of the facts adduced in support of this theory by its author : — ' If we take a survey of the senses, we shall find, that exactly in proportion as each affords an idiopathic sensation more or less capable of being carried to an extreme either of pleasure or of pain, does it afford, but iu an inverse ratio, the condition of an objective perception more or less distinct. In the senses of Sight and Hearing, as contrasted with those of Taste and Smell, the counter proportions are j^recise and manifest and precisely as in animals these latter senses gain in their objective character as means of knowledge, do they lose in their subjective character as sources of pleasurable or painful sensations. To a dog, for instance, in whom the sense of smeU is so acute, all odours seem, in themselves, to be indifferent. In Touch or Feeling the same analogy holds good, and within itself ; for, in this case, where the sense is diffused throughout the body, the subjective and objective vary in their proportions at different parts. The parts most subjec- tively sensible, those chiefly susceptible of pain and pleasure, furnish precisely the obtusest organs of touch ; and the acutest organs of touch do not possess, if ever even that, more than an average amount of subjective sensibility. . . . The experiments of Weber have shown, how differently in degree different parts of the skin possess the power of touch proper ; this power, as measured by the smallness of the interval at which the blunted points of a pair of com- passes, brought into contact with the skin, can be discriminated as double, varying from the twenty-fourth of an English inch at the tip of tlie tongue, and a tenth on the volar surface of the third finger, to two inches and a half over the greater part of the neck, back, arms, and thighs. If these experiments be repeated with a pair of compasses not very obtuse, and capable, therefore, OBJECTS WITH FEELINGS. 428 gives rise to a number of interesting phenomena, some of which may be introduced here, as presenting a new case of the associating process. In the pleasures and pains derived through the various senses and through the moving organs, there spring up associations with collateral things, the causes or frequent by a slight pressure, of exciting a sensation in the skin, it will be found, that whilst Weber's observations, as to the remarkable difierence of the different parts in the power of tactile discrimination, are correct ; that, at the same time, what he did not observe, there is no corresponding difference between the parts in their sensibility to superficial pricking, scratching, etc. On the contrary, it will be found that, in the places where, objectively, touch is most alive, subjectively feeling is, in the first instance at least, in some degree dead- ened ; and that the parts the most obtuse in discriminating the duplicity of the touching points, are b}- no means the least acute to the sensation excited by their pressure. 'For example; — The tip of the tongue has fifty, the inferior surface of the third finger ticentij-five, times the tactual discrimination of the arm. But it will be found, on trial, that the arm is more sensitive to a sharp point applied, but not strongly, to the skin, than either the tongue or the finger, and (depilated of course) at least as alive to the presence of a very light body, as a hair, a thread, a feather, drawn along the surface. In the several places the phaenomena thus vary : — In those parts where touch proper prevails, a subacute point, lightly pressed upon the skin, determines a sensation of which we can hardly predicate either pain or pleasure, and nearly limited to the place on which the pressure is made,' etc. (Edition of Reid, p. 863). On these last experiments, I would remark,— first, that the tongue is scarcely a fair subject of comparison with the skin, seeing that the two tissues are not of the same nature — a matter of considerable importance as regards a pleasurable or painful irritation ; and, therefore, the fairest mode of conducting the trial is skin with skin. Secondly, if trial were made of the cheek compared with the other parts, the inverse proportion contended for would not hold good. To a prick, or a smart blow, the cheek is at least as sensitive as any portion of the skin what- ever ; but it is certainly not the least discriminating in Weber's scale. In fact, it stands high in the scale, being equal to the palm of the hand and the extremity of the great toe, and inferior only to the tongue, lips, and fingers. In this case, therefore, the inverse ratio of sensibility and discrimination does not subsist. Taking the cheek and the back of the hand as compared with the palm of the hand, one would be disposed to say that the sensitiveness to pain varied with the structure of the cuticle, while the discrimination depends solely on the supply of nerves. Let the cuticle be thickened, as in the hand and foot, and the parts are rendered obtuse to a blow. But, where the cuticle is thin, the 424 RETENTIVENESS — LAW OF CONTIGUITY. accompaniments of those feelings. Thus, we connect the pleasures of repose with an easy chair, a sofa, or a bed, and the pleasures of riding witlj a horse and carriage. The sight of food recalls a certam part of the pleasure of eating. The preparation of meals and the catering for the table are inter- esting avocations, through a reference to the end they serve. The representation to the eye of fragrant flowers in a paint- ing, has power to revive some of the pleasures that we gain from the reality through the sense of smell. The pleasures of music, in so far as they can be enjoyed in the retrospect, are evoked by association. We have seen that it is a quality of some feelings to be more recoverable ni idea than others. For example, the pleasures of music and of spectacle are recovered from the past more completely than the pleasures of exercise, repose, waiiuth, or repletion. When those higher feelings are re- vived, by means of association, a much greater approach is made to the intensity of the actual experience. 47. It will not be out of place to select a few examples skin is correspondingly tender or susceptible to painful or pleasurable irrita- tion. This is a popular belief, whether scientifically true or not. Any one keenly alive to a smart or an attack is said to be fMn-skinncd. In addition to this, I am disposed to believe that the parts nearest the brain are in con- sequence more sensitive than remote parts. The agonies of toothache, face- ache, pains of the nose and ear, appear to be more intense than would arise from similar irritations in the lower extremities. If this be a general rule, the skin of the face would be more sensitive than the skin of the arm or the hand, and these more than the leg or foot. In so far as the differences of sensibility and discrimination depend on the miyid, Sir W. Hamilton's theory of inverse relation is more strictly applicable. It is to me quite evidert that, if the whole mind and attention be concentrated on the sensation as a feeling, as giving pleasure or pain, there will be a lack of attention to the intellectual quality. But, then, it is possible that the mind should be awake to both qualities, and to the one for the sake of the other. This is true within certain limits of intensity of sensation (see p. 105). Mr. Spencer has criticized Hamilton's doctrine {Fiychology, vol. ii. p. 248), and has summed up the result in the following sentence :— ' Generalizing the facts, then, it would seem, not that Sensation and Perception vary inversely, but that they exclude each other with degrees of stringency which vary in- versely '. THE EMOTIONS BECOME AFFECTIONS. 425 of the association of the deeper emotions of the mind with the notions that we have of outward things ; by which con- nexion these emotions also can be made present in the absence of their proper stimuhis. The emotions of Tender- ness, Self-complacency, Irascibility, Terror, etc., when stimulated repeatedly in the presence of some one object, enter into mental partnership with that object ; and the two individuals of the couple are thenceforth able to revive each other, the object recalling the emotion, and the emo- tion restoring the object. The emotion of Natural Tenderness is brought out chiefly towards sentient beings, and, after a time, arises habitually in connexion with certain persons or living creatures, who are then said to be objects of affection or attachment. The feeling, moreover, overflows upon places and things, insti- gating a tender regard towards inanimate nature. The associations with home, with one's native spot, with the tokens of friendship and the relics of the departed, are made powerful by all the causes that give force to the contiguous bond. The natural abundance of the emotion in the character, repetition, a good natural adhesiveness, the dis- position to cultivate this peculiar region of associations — all contribute to strengthen the link that enables persons or things to diffuse tender feeling over the mind. AVe may suppose some mental constitutions to have a natural retentiveness for special emotions, just as there are intellects retentive of visible pictures, music, or language ; this reten- tiveness not being identical with the strength of the emotion in the reality. Such persons would be peculiarly qualified to cultivate associated feeling — to derive pleasure from the relics and the memory of affection, and to make this pleasure an object of pursuit in life. The illustration for objects of hatred and aversion, and for all the outgoings of the Irascible passion, would be an exact parallel. This passion connects itself with persons, with places, things, events, etc. ; and may then be revived by objects that of themselves have no original power to stir 426 RETENTIVENESS — LAW OF CONTIGUITY. it up. AYe are apt to feel an aversion to places where we have suffered deep injuries, and to the unwitting instruments of calaniit}^ and wrong. Egotistic and Selfish emotion diffuses itself over all matters related to self ; and the objects that a man surrounds himself with, come to reflect the sense of his dignity and importance. According as this feeling is indulged, associa- tions grow up between it and a great variety of things. Possessions, office, the fruits of one's labour, the symbols of rank, are all overgrown with this connexion, and radiate the feelings of self-complacency and importance to the mind. The members of one's family are objects, not simply of tender affection, but of affection and egotism combined. So with friends, and with all the objects of our habitual admiration. It is impossible to be in the constant practice of loving or admiring anything, without coming at last to connect the object with self ; the disinterested emotion that first attracts us to persons becomes, by indulgence, interested affection. 48. The pleasure of money is a remarkable instance of associated feeling. The sum total of purchasable enjoyments becomes linked in the mind with the universal medium of purchase, and this medium grows into an end of pursuit. In the first instance, we are stimulated by these other pleasures ; but an affection is often generated at last for money itself. This transfer is brought about when we allow ourselves to be so engrossed with the -pursuit of wealth, that we rarely advert to the remote ends or the purchasable pleasures ; the mind dwelling solely on the one object that measures the success of our endeavours. A moderate pursuit of gain that leaves the mind free to dwell upon the pleasures and advantages that money is to bring, does not generate that intense affection for gold as an end constituting the extreme form of sordid avarice. We may extend the survey to Utility on the great scale, and shall find innumerable examples of strong feeling gener- ated through Association. The most striking aspect in this ASSOCIATES WITH UTILITY. 427 operation is presented by all the various means of deliverance from pain. In proportion to the degree and continuance of a painful experience, is the reaction growing out of its present alleviation or removal and the security against its recurrence. The impressiveness of such experiences is the very maximum of aids to intellectual retention, with which comes re- membered satisfaction or acute pleasure. This is, no doubt, the greatest influence in developing the pleasures of pro- perty and power, as the greatest securities for worldly sufficiency and the absence of privations. The chief anomaly in the growcli of intense avariciousness is the fact, sometimes encountered, of its being present in minds that have never passed through the phase of penury or privation. The consideration of such cases might lead us to dwell more upon the egotistic phase of wealth in gi\'ing power, importance, and, it may be, the means of beneficent outgoings — all which are associates sufficiently strong to operate successfully without the aid of fore- gone privation. As minds differ in all these various suscepti- bilities, so do the sources and supports of avarice also differ ; while, on the other hand, the passion may be quelled or en- feebled or diverted by other powerful tendencies of the mind, and, more especially, the sympathies or altruism of the character. Another example of an association displacing the original source and purpose of a feeling, is seen in connexion with the forms of business. Book-keeping, legal formalities, and technical procedure, are intended as aids to the transaction of business. In themselves nothing, they have a great value in furthering our substantial ends; and we contract a sentiment towards them on that ground. As with money, however, this reflected interest sometimes detaches itself from the original ends ; and we take a pleasure in maintaining formalities that time and change have reduced to an empty letter. Among the numerous examples of well-formed associa- tions with objects of utility, such as to rank among the standing interests of life, we may cite fondness for accurate timekeepers by men like the Duke of Wellington who have 428 EETENTIVENESS — LAW OF CONTIGUITY. "had to adjust and fit together vast and complicated opera- tions ; an association also fostered in the days of railway communication with those that have frequent occasion to travel. Another striking instance of associated effects may be seen in the pleasure of polished surfaces, and the repug- nance to rust and roughness — the one associated with easy motion in inachinery, the other with obstruction and diffi- culty. The circumstance of noiselessness in machines is similarly gratifying ; while a grating sound pains both the primary susceptibility of the ear and the secondary feelings connected with mal-adjustment and difficulty. Inasmuch as ill health is the cause of a large portion of human suffering, the signs and symptoms of robustness on the one hand and disease on the other, become highly sug- gestive of pleasurable and painful feeling. The result may be interfered with by aesthetic suggestion, which does not always coincide with what is healthy and vigorous in form and appearance. 49. Alisonian Theory of Beauty. — This celebrated doctrine exemplifies the case of contiguous association now in hand, in so far as we are dis- posed to admit the application that its author makes of it. That he has carried his theory of associated pleasure too far might, I think, be shown in numerous instances. We have already seen that all the senses yield us sensations that are in themselves pleasm-able, without reference to any associated effect. There are fragrant odours, sweet sounds, and pleasing effects of light and colour, in which the pleasiu"e is owing to a direct and immediate action of the objects iipon the organs of sense ; and these pleasurable feelings never fail to be produced when we are in a condition to enjoy them. There would be nothing permanently or generally pleasing, if we had not a certain number df such primary sources of enjoyment. But tlie doctrine of Alison satisfactorily explains the strong effects often produced on our minds by sensations and objects, in themselves indifferent, or wholly unequal to those effects. A few instances of this sort may be quoted as true examples of borrowed or associated emotion. Take the case of sounds: 'All sounds,' says Alison, ' are in general SUBLIME, which are associated with ideas of great Power or Might : the Noise of a Torrent ; the Fall of a Cataract ; the Uproar of a Tempest ; the Explosion of Gunpowder ; the Dashing of the Waves, etc' Most of ASSOCIATION THEORY OF BEAUTY AND SUBLIMITY. 429 these sounds, however, are intrinsically impressive from their intensity and volume, and the effect that they have on the mind is not wholly due to association. The following is a better selection for the purpose in hand : — ' That the Notes or Cries of some Animals are Sublime, every one knows ; the Roar of the Lion, the Growling of Bears, the Howling of "Wolves, the Scream of the Eagle, etc. In all these cases, those are the notes of animals remarkable for their strength, and formidable from their ferocity.' In like manner, the author exemplifies associations with the feeling^ of Beauty, as follows : — 'The Bleating of a Lamb is beautiful in a fine day in spring ; the Lowing of a Cow at a distance, amid the scenery of a pastoral landscape in summer. The call of a Goat among rocks is strikingly beautiful, as expressing wildness and independence. The Hum of the Beetle is beautiful on a fine summer evening as appear- ing to suit the stillness and repose of that pleasing season. The Twitter of the Swallow is beautiful in the morning, and seems to be expressive of the cheerfuhiess of that time. A similar illustration can be derived from Colours and appearances to the eye.' The impressive emotion roused by the discharge of thunder can be evoked by the transient flash in the window— an effect in itself very trivial, but able to* recall the gi'ander features of the phenomenon, and, through these, the emotion of the Sublime. The relics of a storm, seen in the disorder and wreck, revive the feeling impressed by the height of its fury. The language that describes such phenomena, when aptly used, can arouse the emotions purely by the force of association. Alison extends the illustration of his doctrine to Forms and Motions, as well as to sounds and coloiu's, and supplies examples in great abund- ance under all these heads. I believe he has here too, in manj' in- stances, set down intrmsic effects as the effects of association ; but, nevertheless, he has put it beyond dispute, that the associating principle operates largely in clothing indifferent objects with a power to raise emo- tion in the mind of the beholder. There is, I am satisfied, a primitive influence in form to produce a certain amount of emotion, of the kind that enters into the compositions of Art. Curved forms and winding movements yield, of themselves, a certain satisfaction through the muscular sensibility of the eye. Yet, we must add to this original impressiveness an influence of association ; namely, the connexion of ease and abandon with the curve Ime, and of constraint with the straight line. The free natviral movements of the arm make circular figures : to draw a straight Ime requires an effort. .50. The Reading of Emotional Expression. — An interesting case of associated feeling is our being able to interpret the signs of feeling in our fellow-beings — by which we are not 430 EETENTIVENESS — LAW OF COXTIGUITY. merely made aware of their state of mind, but also derive a large amomit of painful and pleasurable feeling to ourselves. The influence of the smile or the frown, so powerful in human life, is apparently an associated influence. There is nothing intrinsic in the lines and forms of feature, displayed in the act of smiling, to cause the pleasure occasioned by this manifestation. Incidentally, fine forms and curves may be produced in a face, and there may be a display of beautiful tints over and above ; but, when these things occur, they constitute an additional pleasure. The meaning of a smile, together with the susceptibility to the cheering^influence of it, are supposed to be learnt among the early acquisitions of infancy. The child observes that this expression accompanies the substantial pleasures that need no association to give them their character. The smile of the parent, or of the nurse, means all the agreeables of food, dress, play, spectacle, excitement, society. The frown is as invariably connected with privation and pains. An enduring association thus comes to obtain between one cast of features and all the good things of life, and between another expression and the ills that human power can inflict ; and, hence, the one is able to diffuse a gladdening influence, while the other tends to excite a feeling of depression and gloom. All through life, we are subject to these influences of associated emotion. So, there are tones of voice that, in the same way, can cause pleasure or pain by a power of sugges- tion. In this case, however, there is a certain intrinsic eflicacy in the tones usually adopted to convey the intended effect. For conveying love and approbation, we choose our soft and gentle tones ; for the opposite, we are led, both by passion and by choice, to use tones that are painful and grating. There is no original or intrinsic difference of effect between pleased and angry features; but, in vocal utterance, there is a manifest suitability of some tones for pleasing expression, and of others for the reverse. The difficulty already noticed (see the Higheb Instincts) in READING OF EMOTIONAL EXPRESSION. 431 accounting for the early development of the infant susceptibility to the smile and the frown must so far qualify the foregoing statements as to couple hereditary experience with the experience of the lifetime. The affirmation still holds good, that a process of coupling between two distinct classes of facts must have occurred through our natural power of retentiveness. Any other supposition is unsupported by evidence or probability. In adopt- ing the doctrine of heredity, or hereditary transmission, as the explanation of Instinct, we still adhere to the notion of ex- perience, — as opposed to a primary power of suggestion, whereby one sense can reveal what belongs to another (see note F). The great problem of Instinct, as against Acquisition, in this or in any other department, could be reduced to narrower dimen- sions, if we had the means of correctly estimating the pace of acquirement at the period of life open to examination. If we could reduce to some assignable measure the length of time needed for acquiring a given emotional association, and if we could compare the strength of such association with the earliest displays of emotional reading in infancy, we might draw a confident inference as to the necessity of some hereditary initia- tion in those cases. The point may be too subtle for such deli- cate handling ; yet, the disparity is possibly great enough to dispose of any doubt as to the inadequacy of life experience for the purpose. It is a part of our pleasure to see happy beings around us, and especially those that have the power of expressing their feelings in a Kvely manner. Children and animals, m their happy moods, impart a certain tone of gaiety to a spectator. On the other hand, the wretched, the down.cast, and the querulous, are apt to chill and depress those in their company. There is a satisfaction in merely beholding, or even in imagining, the appearances and accompaniments of superior happiness — which probably accomits in part for the disposition to do homage to the wealth}', the powerful, the renowned, and the successful among mankind. Associated emotion is the medium of sympathy with the feelings of others. AVe have to acquire the signs of feeling, in order to make the states of others our own. We learn 432 EETENTIVENESS — LAW OF CONTIGUITY. the natural appearances of the different emotions, and also the names that describe them — which appearances and names are the medimn for realizing them. As in all else, there are great individual differences of progress in this acquire- ment and corresponding differences in the power of sym- pathy. Among the associations of Feeling, we should not omit the important sentiments of moral approbation o^ndi moral dis- approbation. These are admitted on all hands to be greatly the result of education ; indeed, the fact is too notorious to be controverted. The well-trained child constantly finds certain acts spoken of with marked disapprobation, and visited with pain, which gives to disapprobation its mean- ing ; and there grows up, as a consequence, a strong associa- tion between those actions and the feelings of dread and aversion. A high motive power is thus generated for abstaining from lying, theft, cruelty, neglect of studies, and other forbidden acts. This is one side of our moral educa- tion. The other side is, in like manner, a series of associa- tions between certain actions and praise, approval, or reward ; and these determine the acquired sentiment of moral approbation. How little of either of the two modes is to be found where nothing has been done to impress them, is best known to persons that concern themselves with the outcasts of society. The rate of advancement in moral training depends on several circumstances. In the first place, the energy of the impulses that trespass against the laws of society may be strong, or they may be weak, by nature. But, secondly, a still greater importance is to be attached to the aptitude for vividly retaining the penalties, and expressed disapproba- tion, of wrong. This memory for good and evil appears to be a special, or local, mode of retentiveness, as much so as colour or music : it does not always accompany high intellect generally ; and it is occasionally strong, when the power of recollection in other things is weak. It belongs, no doubt, to the same circle of sensibilities that includes our pru- MORAL APPROBATION AND DISAPPROBATION. 433 dential and our sympathetic regards. For, both prudence and sympathy must concur to a well developed moral sense. There are many of our strong likings, on the one hand, and strong antipathies, on the other, that come under the class of reflected influences. The sight of blood affects some persons to fainting — which cannot be owing to anything in the mere appearance of it ; apart from association, the rich scarlet hue would make this a really agreeable object to the eye. ASSOCIATIONS OF VOLITION. 51. I have already adverted to the mistake, committed by Eeid, in pronouncing the voluntary command of our limbs and other moving organs instinctive. If we observe the movements of infancy, we see plainly that, for many months, there is no such thing as a command of the active members, in obedience to an aim or purpose present to the mind. An infant may have sufficient intelligence to form a wish, and be quite unable to execute the simplest movements for attaining the thing wished. A common example of this is the attempt to seize something with the hand, — as a spoon. We see the most awkward movements occurring, — evidently from the entire want of any definite direction of the limbs at that stage. This definite direction is acquired ; and the acquisition is the most laborious and diflicult of all human attainments. The performance of the simple movements that we wish to perform, is the basis of our acquirement of more complex movements at a subsequent stage ; but our first education is self-education. Until a child can, of its own accord, put out its hand and seize an object before its eyes — which for the first few months it cannot do, — any attempt to direct it is in vain ; and, until, of its own accord, it can move its own body as it sees something else moved, it has not begun to be an educable being. The voluntary command of the organs implies the fol- lowing things. 1st, The power of continuing or abating a present movement in obedience to a present feeling, — as when 28 434 EETENTIVENESS — LAW OF CONTIGUITY. the child sucks while the appetite is gratified, and ceases when satiety comes on. So far, Volition is an Instinct. 2ndlv, The power of selecting a movement in order to heighten or abate a present feeling, — as when the child directs its head and mouth to seize the nipple, and begins suckinsf. There mav be a few instances of instinctive movements of this kind ; but, in general, they are acquired, being determined by means of association. The coincidence of the movement and the feeling must be at first accidental. As the movement springs up of its own accord, and finds itself able to control the feeling, the two become after a time so firmly connected that the one suggests the other. Thus, the movement of the eyes and head is at first spontaneous ; but the agreeable feelings of light brought on by these movements prompt then- continuance, and the pleasure grows to be associated with these movements : whereupon, when this feeling is present to the mind as a wish, it prompts the requisite exertions. Thus it is that a child learns to search out a light in a room, in order to enjoy the maximum of the illumination ; it learns to turn its view to the fire, or the window, or to some face that it has begun to recognize agreeably. Volition means, 3rdly, the performance of some intermediate actions with a view to our gratification ; as when things are seized with the hand in order to be carried to the mouth, or when animals, de- scr}ang their food at a distance, set themselves to move forward to lay hold of it. These intermediate actions are most manifestly the result of experience, in the human subject at least. The power of locomotion has first to be developed ; the exerting of the power then becomes associ- ated with its various consequences, and, among others, that of bringing the individual within reach of the objects of its desires. 4thly, The'voluntary command of the organs means the power of imitation, or of performing actions in con- sequence of seeing them performed. Here, a link has to be established between a certain appearance to the eye and the movement of corresponding organs in the individual's ACQUIREMENTS INVOLVED IN VOLITION. 435 self. In the case of vocal imitation, a sound is the antece- dent of an utterance ; each sound heard being associated with a distinct movement of the chest and larynx, under the proper attitudes of the mouth. It is not uncommonly sup- posed that imitation, both of actions and of sounds, is in- stinctive ; but I have doubts whether this be correct. 5thly, Under volition, we include the power of moving our organs merely on the wish to see them moved ; as when I look at my hand, and will to raise it. Here, a connexion is formed between the sensible appearance of any member, or the idea left by that sensible appearance, and its being moved. Lastly, We can make a movement on being directed to do so, by the part being named ; 'up head,' ' down hands,' etc. This is a further association, formed between certain names or sounds and a particular class of movements. All these various actions are employed in the most elementary efforts of the will to control the body. Others could be named that transcend their range of influence, — as, for example, the control of the passions and the command of the thoughts.* * The following are notes of observations made upon the earliest move- ments of two lambs seen during the first hour after birth, and at subsequent stages of their development. The two came from the same mother, and their actions were in the main alike. One of the lambs, on being dropped, was taken hold of by the shepherd, and laid on the ground so as to rest on its four knees. For a very short time, perhaps not much above a minute, it kept still in this attitude. A certain force was, doubtless, exerted to enable it to retain this position ; but the first decided exertion of the creature's own energy was sho^vn in standing up on its legs, which it did after the pause of little more than a minute. The power thus put forth I can only describe as a spontaneous burst of the locomotive energy, under this condition, — namely, that, as all the four limbs ■were actuated at the same instant, the innate power must have been guided into this quadruple channel in consequence of that nervous organization that constitutes the four limbs, one related group. The animal now stood on its legs ; the feet being considerably apart so as to widen the base of support. The energy that raised it up continued flowing, in order to maintain the standing posture ; and the animal, doubtless, had the consciousness of this flow of energy, as its earliest mental experience. Thus standing posture was continued for a minute or two in perfect stillness. Next followed the beginnings of locomotive movement. At first, a limb was raised and set down again ; then came a second movement that widened the animal's base 436 EETENTIVENESS — LAW OF CONTIGUITY. 52. Ill order to illustrate the acquired character of these several voluntary actions — excepting always the first, namely, the continuino; or abating of a present movement in obedi- ence to a present feeling — I shall select the case of Imitation. If we can prove satisfactorily that this is not instinctive {i.e., instinctive as usually conceived), but acquired, little doubt wall remain on the other cases. without altering its position. When a more complex movement with two limbs came on, the effect seemed to be to go sideways ; another complex movement led forwards ; but, at the outset, there appeared to be nothing to decide one direction rather than another, for the earliest movements were a jumble of side, forward, and backward. Still, the alternation of limb that any consecutive advance required, seemed within the power of the creature during the first ten minutes of life. Sensation as yet could be of very little avail ; and it was evident that action took the start in the animal's history. The eyes were wide open ; and light must needs have entered to stimulate the brain. The contact with the solid earth, and the feelings of weight and movement, were the earliest feelings. In this state of uncertain wandering with little change of place, the lamb was seized hold of and carried up to the side of the mother. This made no difference, till its nose was brought into contact with the woolly skin of the dam, — which originated a new sensation. Then came a conjunction, manifestly of the volitional kind. There was clearly a tendency to sustain this contact, — to keep the nose rubbing upon the side and belly of the ewe. On finding a certain movement to have this effect, that movement was sustained ; exemplifying what I consider the primitive or fundamental fact of volition. On losing the contact, thsre was as yet no power to recover it by a direct action ; for, the indications of sight at this stage had no meaning. The animal's spontaneous irregular movements were continued. For a time, they were quite fruitless ; until a chance contact came about again, and this contact could evidently sustain the posture or movement that was causing it. The whole of the first hour was spent in these various movements about the mother ; there being, in that short time, an evident increase of facility in the various acts of locomotion, and in commanding the head in such a way as to keep up the agreeable touch. A second ho\ir was spent much in the same manner ; and, in the course of the third hour, the animal, which had been entirely left to itself, came upon the teat, and got this into its mouth. The spontaneous workings of the mouth now yielded a new sensa- tion, whereby they were animated and sustained, and, unexpectedly, the creature found itself in the possession of a new pleasure — the satisfaction first of mouthing the object, next, by and by, the pleasure of drawing milk. The strength of this last feeling would, doubtless, give an intense spur to the co-existing movements, and keep them energetically at work. A new and grand impression was thus produced, remaining after the fact, and stimulating exertion and pvirsuit in order to recover it. VOLUNTARY ACQUISITION IN ANIMALS. 437 (1) The first argument against purely instinctive imitation is the fact, that no imitation whatever takes place during the first few months of infant existence. So far as my observa- tion goes, there is very little during the first year. But a primitive impulse ought to appear much earlier. The in- stinctive movements discussed in the preceding Book, show Six or seven hours after the birth, the animal had made notable progress. Locomotion was easy ; the forward movement being preferred, but not pre- dominant. The sensations of sight began to have a meaning. In less than twenty-four hours, the animal could, at the sight of the mother ahead, move in the forward direction at once to come up to her — showing that a particular visible image had now been associated with a definite movement ; the absence of any such association being most manifest in the early movements of life. It could proceed at once to the teat and suck, guided only by its desire and the sight of the object. It was now in the full exercise of the locomotive faculty ; and very soon it could be seen moving, with the nose along the ground in contact with the grass — the preliminary of seizing the blades in the mouth. I am not able to specify minutely the exact periods of the various de- velopments in the self-education of this lamb ; but the foregoing are con-ect statements to the best of my recollection. The observations serve to prove dis- tinctly these several points, — namely, first, the existence of spontaneous action as the earliest fact in the creature's history ; second, the apparent absence of any definite bent prior to experienced sensations ; and, third, the power of a sensation actually experienced to keep up the coinciding movement of the time, thereby constituting a voluntary act in the initial form. The truly remarkable circumstance in the case was the rate of acquisition, or the rapidity with which all the associations between sensations and actions became fixed. A power that the creature did not at all possess naturally, got itself matured as an acquisition in a few hours ; before the end of a week, the lamb was capable of almost anything belonging to its sphere of existence, and, at the lapse of a fortnight, no difierence could be seen between it and the aged members of the flock. It is, however, this circumstance of extreme rapidity in the pace of acqui- sition that casts suspicion upon the inference that the sole explanation of the niatured aptitude of those quadrupeds is to be found in their brief experience. Everything else is consistent with such a view ; but the education of an animal cannot be assumed to proceed at such a rate, and we are driven rather to assume something in the primordial constitution that paves the way for the aptitudes in question. True, there is not the same decisiveness in the instinctive capabilities of quadrupeds as in those of birds ; but the analogy is close enough to support the inference that a power matured at birth in the one case is so far advanced in the other as greatly to shorten the process of education (see Highek Instincts, p. .329). 438 EETENTIVENESS — LAW OF CONTIGUITY. themselves from the very commencement of Hfe. There is no nevi^ development or manifestation of power at the time when the imitative propensity comes on : there is nothing parallel, for example, to the physical changes that show themselves at puberty, along with the new feelings of that period. The child is seen to go through a great deal of active exertion of its own, in the course of those unimitative months. The power of repeating the actions of others would be exceedingly valuable at this time, and would save much fruitless endeavour ; but the very faintest tendency in this direction cannot be discerned. There may be instances of a more precocious faculty than an}' that I have observed, but these would not affect the present argument. (2) In the second place, imitation, when it does begin, is slow and gradual in its progress —a fact that looks like acqui- sition, and not like instinct. AVe find, for example, that, in Speech, the imitacion is at first limited to one or two arti- culations, and that others come on by degrees at consider- able intervals. If there were any primitive connexion in the brain between a sound heard, and the reproduction of that sound with the voice, it ought to be as good for one letter of the alphabet as for another. So with the move- ment of the hand : why should one movement be possible, while no amount of example will bring out a second, not in itself more difficult ? (8) The imitation very often fails, after it has once been hit. x4. child has caught a certain sound, and will, at parti- cular times, produce it ; yet, at other times, there is no pos- sibility of bringing on the utterance. This is constantly seen in the first efforts of children. It is in vain that we repeat to them a sound, a letter, or a syllable that they have shown themselves able to pronounce ; the association between the audible impression and the specific vocal exer- tion has plainly not yet been formed : it cannot, therefore, be instinctive. The child has, in the course of its spontane- ous articulate movements, come on the sound hum, and this sound once pronounced is likely to recur in the cycle of its THE POWER OF IMITATION ACQUIRED. 439' spontaneous actions ; but to utter the syllable at the in- stance of another person's utterance is something additional. I can easily render to myself an account of the process, re- garded as an acquisition. The sound spoken is also heard — i.e., besides the vocal exertion, there is a coincident impression on the ear. x\n association grows up between the exertion and the sensation, and, after a sufficient time, the one is able to recall the other. The sensation, anyhow occurring, brings on the exertion ; and when, by some other person's repeating the syllable, the familiar sound is heard, the corresponding vocal act will follow. Experience, I think, proves that the time elapsing between the ability to utter a sound, and the readiness to utter it on its being heard, corresponds to the time requisite for an adhesion to grow up between the two heterogeneous elements — the one a spontaneous action, the other a sensation. These early sounds come out more fre- quently of themselves than under the stimulus of imitation, — which proves that the exertion precedes the power of imitating. If imitation be instinctive, there must be several thou- sands of instinctive connexions between sensations and actions. The sound of each letter of the alphabet, and every word, would require to be connected, by a primitive adhesion, with definite movements of the larynx, the mouth, and the chest. Every movement of the hand would need to be associated with the visible appearances of the same movement in other human beings. We should have to affirm the manifest absurdity that associations could be formed between things yet unexperienced — between sounds, and sights, and actions, long before anything had been heard, seen, or done. (4) It is notorious to observation, that more can be done by the nurse imitating the child, than by the child imitating the nurse. AVhen an articulation is stumbled on, it is caught up b}' all around, and the child is made familiar with the sound as proceeding from other voices, in addition to its own. This would, obviously, promote the growth of the needful adhesive connexion. 440 EETENTIVENESS — LAW OF CONTIGUITY. (5) Imitation varies with the natural abundance of spon- taneous activity; being most efficient where the spontaneous variety and flexibihty are good. A child will learn to imi- tate singing, in proportion as, of its own accord, it falls into musical notes. Its own native song must come first : the goodness of that will be a condition of its acquiring the song of others. In whatever department any individual shows spontaneous and unprompted facility, in that dejjartment will the same individual be imitative or acquisitive. (6) Imitation advances with the acquired habits. In learning to dance, the deficiency of the association between the pupil's movements and the sight of the master's, renders the first steps difficult to acquire. The desired movements are not naturally performed at the outset. Some movements are made — sufficient voluntary command of the limbs and body has been acquired, iu other shapes, to set going action of some kind ; but the first actions are seen to be quite wrong ; there is a manifest want of coincidence, which originates new attempts ; and these failing, others are made, until at last the posture is hit. The grand process of trial and error brings on the first coincidence between a move- ment, and the appearance of that movement in another per- son ; repetition, by constituting a cohesive link, makes the imitation at last easy. Upon this acquisition, other acquisi- tions of the same kind are based, and the improvement is accelerating. Thus it is that we pass through an alphabet of imitation in all arts : the fixing of the association in the first links is the most difficult part of the process. (7) It is in harmony with all that has now been ad- vanced, that imitation depends likewise on the delicacy of the sense that perceives the effect. This is not the place to exhaust the subject of Imitation, in particular, or the acquisitions that enter into volition, in general. It is enough, for the present, to show that the asso- ciative principle is an indispensable requisite here as else- where. All the conditions already specified, as affecting the rate of adhesiveness in other acquirements, might be exem- IMITATION MAY HAVE AX INSTINCTIVE PREPARATION. 441 plified likewise in these. The great pecuharity in their case arises from the circumstances of their commencement. Being the starting-point of every other branch of education, they must find their own way through struggles and acci- dents, trials and failures. Reposing upon the great funda- mental link between consciousness and present action, — - between pleasure or pain, and the activity happening at the time, — they come at last to supply definite connexions between our feelings and exertions, so as to enable us, not merely to control a movement at work, but to call dormant actions into being at the instance of our reigning desire. Of the various circumstances affecting the progress of these volitional associations, the engagement of the cerebral energy or concentrated attention is of signal consequence. This condition, necessary at any age, seems the all-important one in the early months of our existence. The moment of an acquisition seems generally to turn upon some happy concurrence of aroused attention, or mental engrossment, with the action ; if an impression is not detained for a time by the influence of some feeling, it is void of effect. When the child hits upon an exercise that gives it pleasure, and is thereby led to repeat the act, earnestly and intently, the occasion is sure to bring a sensible advance in fixing the whole connected train. As in other connexions, I have to qualify the foregoing explanation by admitting the possibility and the fact of heredit- ary transmission, in, at least, preparing the way or giving facilities for the operation now described. Eeferring again to the situation of the young quadruped, which, in a few days after birth, can follow the movements of the parent in feeding itself, we may presume that the inheritance of tendencies favouring acquisition may decisively contribute to the advancement of our early powers of imitation. The term " Instinct" would thus have a certain fitness, it being understood that it expresses simply an undefined amount of transmitted aptitude in aid of our education as above portrayed. 442 eetenti\':eness — law of coxtiguity. natural objects— aggregates of natural qualities. 53. One of the principal components of human intelhgence is our permanent hold of the external, or object, world, as it strikes the senses. External things usually affect us through a plurality of senses. The pebble on the sea shore is pictured on the eye as form and colour. AYe take it up in the hand, and thereby obtain the impression of weight, together with the tactile sensation of the surface. Knock two pebbles together, and there is a characteristic sound. Take also a billiard ball: ' its colour is one attribute which I signify by calling it white ; its figure is another which is signified by calling it spherical ; the firm cohesion of its parts is signified by call- ing it hard ; its recoiling, when it strikes a hard body, is signified by its being called elastic ; its origin, as being part of the tooth of an elephant, is signified by calling it ivory ; and its use by calling it a billiard ball '. To retain the impression of an object of this kind, there must be an asso- ciation of all these different eifects. Such association, when matured and firm, is our idea, our intellectual grasp, of the ball. Passing to the organic world, and plucking a rose, we have the same effects — form to the eye and to the hand, colour and tactile properties, with the addition of odour and of taste. A certain time is requisite for the coherence of all these qualities in one aggregate, so as to give us the enduring image of the rose. AVhen fully acquired, any one of the characteristic impressions may, under given circumstances, revive the others. The odour, the sight, the feeling of the thorny stalk, — each of these by itself will hoisf the entire impression mto the view. Should we go to work and dissect the fiower botanically, we obtain new impressions to enter into the common aggregate. It is by rapidly associating these qualities, — in other words, by the ready adhesion of impressions of sight, touch, and the other senses, — that a person becomes at last conversant COMPLEX OBJECTS OF SENSE. 443 with Mineral, Vegetable, and Animal bodies. In the mind of the Naturalist, the sensations of sight and of touch, more especially, must take a ready hold. A good general ad- hesiveness, aided by the special or local susceptibilities, is chiefly to be depended on. The element of concentration of mind must be present likewise, in the shape of an interest for the study. To this requisite, however, we must attach an important qualification. AA'hen a department of acquisi- tion involves a great mass of detail, the attention, spread over a wide area, cannot be strongly concentrated at any point. The natural or unprompted adhesiveness, whether from general or from local endowment, is called for alike in Natural History and in Languages. The power of observation ever fresh and buoyant, the energy of the brain thrown into visual and tactile sensation, are characteristics not of the naturalist alone, but of all men that deal w^ith outward things in the concrete— as the en- gineer, the military commander, and the poet. In those things that appeal to other senses also — as articles of food, — there is an additional motive, growing out of their special interest. So, there may be a superadded charm of the artistic kind, as in the precious stones, determining a prefer- ence, with some minds, for all objects of a nature to gratify the artistic sensibilities. But the naturalist should be above such partialities ; to him every natural object must possess a moderate interest, and no one more than a fair share : it is only by this moderation that he can keep his mind equal to the multitude and variety of nature. 54. From the objects of the world thus apprehended, as they strike the immediate sense, we pass to a higher group of aggregates,' — things with properties not always present to the view. For example, a cup in its completeness must be con- ceived as containing something, as serving this purpose or use. AVe have to associate with the permanent sensible qua- lities this other quality of usefulness for some end, which has a special interest in it to quicken our retentiveness of the entire total. Furniture and tools and implements of every 444 RETENTIVENESS — LAW OF CONTIGUITY. description have this superadded quahty, — which, however, instead of burdening the memory, rather hghtens it by the spur of a special interest. All related objects are more easily fixed in the mind than those that are um'elated, particularly if the relation be an interesting one. A monarch is more im- pressive than a man ; a millstone is more firmly remembered than a useless block on a moor. When the interest in indus- trial production is naturally high in an individual, every kind of machine arrests the regards and makes a stronger impres- sion. AVe have here another example of that select or special attention, which concentrates the mind upon some things to the neglect of others, and is also in strong contrast with the catholic tendencies of the naturalist mind. Not only is there a restriction as regards the objects in the narrow point of view, but the properties attended to are more limited. If a tool has a good edge, its specific gravity is a matter of indifference ; if a quarry yields good building stone, the owner leaves it to others to determine its mineral composi- tion and its geological era. NATUEAL AND HABITUAL CONJUNCTIONS— STILL LIFE. 55, The things about us that maintain fixed places and relations, become connected in idea as they are in reality, and we thus lay up a phantasmagoric representation of our habitual environment. The house we live in, with its furniture and fittings, the street, town, or rural scene that we encounter daily, by their incessant iteration, cohere into abiding recollections ; and any one part easily brings all the rest into the view. These familiar haunts exemplify pic- torial adhesion in a high degree ; numerous repetitions and lively interest combine to the result. We, likewise, associate a number of human beings with their abodes, dresses, avocations, and all other constant accompaniments. Objects at a distance from our daily circle afford a better opportunity of testing the natural adhesiveness of the mind for pictorial expanse. A house we have visited only once or twice, a strange street, a new scene, puts to the proof the EECOLLECTION OF SCENES OF NATURE. 445 visual persistence of the mind. This resolves itself partly into the case of coloured impressions, and partly into that of visual forms ; the tenacity for colour being the essential point. If the sense of colour is not very powerful, a coloured decoration is quite irrecoverable. The same may be said of a heterogeneous and formless collection of orna- ments or curiosities. The recollection of dresses turns principally upon the hold we have of colour. The interior of a room implies form, and may be retained as such ; but, if the sense of colour is indifferent, it will be revived only in outline. A garden, a shrubbery, an array of fields, also rely upon the coloured element. The more irregular the outlines of things are, the more do we depend upon the tenacity of the mind for coloured impressions. Thus, for the easy retention of the variegated imagery of the world about us in all its richness, the first requisite isa powerful adhesiveness as regards colour. This gives to the mind a pictorial character — an attraction for the concrete of nature, with all the interest thence arising. We have just seen how far it belongs to the naturalist ; it is also the common basis of character in the Painter and the Poet; for, although both these have to select, from the multitude of appearances, such of them as have an interest in art, yet they should be so constituted as to keep a hold of anything that presents itself to the eye, whether beautiful or not. A luxuri- ant imagination implies the facility of retaining scenes of every description ; nothing less could sustain the flow of a great poet. All objects may not be beautiful or picturesque, yet there is hardly any appearance but may enter effectively into some composition ; and the poet-painter needs to be a person of strong disinterested retentiveness for everything that he sees. Any one stopping short at this point would be a naturalist simply ; but, when the poetic sense is added, to lay a special stress upon the beautiful, grand, or touching objects, the naturalist passes into the artist. A strong artistic sense, without the broad disinterested hold of nature's concrete in general, may make a man a genuine or even an 446 EETENTIVENESS — LAW OF CONTIGUITY. exquisite artist, but thin and meagre in his conceptions — great taste, with feeble invention. It appears, then, that, in respect of cohesiveness, the habitual conjunctions of objects differ but little from the individual concretes. The retentiveness of the sense of Sight is the mainstay of both the one and the other : in the smaller and more accessible objects, we bring in touch and the other senses ; in the sphere of the large and the remote, we embody the images in sight alone. 56. Among the important aggregates implied under the present head, I may include those artificial representations intended to aid the conception of the outer world, — as, for example, Maps, Diagrams, and Pictorial Sketches. A very great utility is served by these devices, and much intellectual power and practical skill depend on our being able to associate and retain them. The Geography of the globe is summed up in an artificial globe, or in a set of maps, with outline, shade and colour, to correspond with the differences of sea and land, mountain and plain. There are very great dif- ferences among individuals in remembering a map. A good adhesiveness for colour is still an important element, just as in the recollection of the actual surface of a country. It is a case of that facile retentiveness of a great multitude of impressions, that contrasts with the severe hold of a few selected ones — an extensive rather than an intensive grasp. Next to maps, we may reckon Natural History sketches which contain a great variety of appearance depending much upon differences of colour. Anatomical diagrams and the drawings of machinery are of the same nature, but incline to the diagrams of abstract science, where attention is strongly concentrated on few and limited features. When we come to the figures of Euclid, colour entirely disappears as an element ; the pictorial retentiveness is of no avail. Form is everything ; and that Form is not various, but limited, and exceedingly important. This illustrates, by contrast, the power of seizing nature's aggregates and con- cretes, where thousands of distinct impressions must fall THE EXPERIMENTAL PROPERTIES OF THINGS. 447 into their places and cohere with ease, and in a short time. A crowded theatre and the forty-seventh of Euchd are eqiiaUy objects to the eye, and also to the conceiving mind when they are gone ; but the region of the brain that deter- mines the adhesiveness must be quite different in the two cases : in the one, we have colour and variegated form ; in the other, a few regular forms with negation of colour. 57. There is an important class of artificial conjunctions, wherein the obvious appearances of things are associated with other appearances brought out by Manipulation and Experiment. The properties of a Mineral — the complete notion that we can attain respecting it — are a combina- tion of the sight and the touch with the artificial aspects made by a process of measuring angles — a fracture, a scratch, the blowpipe, the application of an acid. A complex im- pression is thus stamped on the mind : at an after time, any one of the characteristic properties will, under certain qualifications, revive the total conception of the mineral. So in Chemistry ; each substance is conceived, not simply as seen and handled by itself, but as acted on by many other substances, by changes of temperature, and so forth. The chemist's notion of sulphur is a large aggregate of appear- ances and sensations produced in various ways ; it is, in fact, the notion of a great collection of substances — the compounds of sulphur,— as odour of burnt brimstone, oil of vitriol, salts of sulphuric acid, compounds of sulphur with metals, etc. In like manner, the properties of a plant are not completely summed up and aggregated in the mind, till, in addition to all the aspects it presents by itself, other aspects are taken along with it, brought out by dissection and manipulation. This is an exact parallel to an example occurring under the immediately preceding head, — namely, tools and machinery, — where the present aspect has to be conjoined w4th other appearances, shown when they are put to their practical uses. In these mineral and chemical aggregates, there is great scope for proving the force of contiguous association, but still 448 EETENTIVENESS — LAW OF CONTIGUITY. more for testing the disposition to dwell upon artificial com- binations, — the results of previous analysis or forced separa- tion of natural conjunctions. Science is repellent, from the necessity of dissociating appearances that go naturally and easily together, of renouncing the full and total aspect of an object whereby it engages agreeably the various senses, and of resting upon some feature that has no interest to the common eye. Those compounds of sulphur that have to be conjoined with the simple substance as a part of its idea, are constantly viewed by the chemist under the one aspect of composition or decomposition in the contact with other bodies : the appearance of any single substance to the eye may be wholly irrelevant to any purpose of his. SUCCESSIONS. 58. If we except complex and coinciding muscular move- ments, and the concurrence of sensations through different senses at the same moment, all associations are successive to the mind, seeing that we must pass from the one to the other, both in the original experience and in the subsequent recollection. The features of a landscape can be conceived only by successive movements of the mind, as it can be seen only by successive movements of the eye. But we here contrast, with the uniform successions that result in the Simultaneous, the variations or changed aspects of things, called Successions proper. We may notice, first, the successions that go round in a cycle, without shock or interruption, — as day and night, the phases of the moon, the course of the seasons. The different aspects presented by the sky above and the world around, in the course of the solar day, are associated in our minds in their regular order, and anticipated accordingly. This cyclical association makes up one part of our knowledge, or experience of the world, and guides our actions in accordance with it. Such slow and tranquil changes become coherent under almost the very same conditions as the aspects of still life that we view in succession by moving from place to place. SUCCESSIONS OF THE EVOLUTION OF LIVING BEINGS. 449 The two cases are very different in themselves ; but, to the mind, the contemporaneous in reahty is the successive in idea. The flow of moviiu/ nature is associated in one con- stant direction ; whereas the mental association of still nature is backward and forward in various directions : yet, the same mental adhesiveness that embraces the one, embraces the other. A second class is comprised by successions of evolution — as the development of a plant, or an animal, through all its stages, from the germ to the decadence. The associations of these, as they occur in nature, make up our knowledge of the history of living things. The peculiarity of the case is the continuity and identity of the main subject, and the likeness that prevails in the midst of change ; both circum- stances assisting to impress the different stages upon the recollection. If we have already formed an enduring picture of a fir sapling, we have not much difficulty in conceiving it merely expanded in dimensions, the form and tex- ture remaining the same ; and so with any other plant or animal. Where a creature undergoes a radical transforma- tion, as a butterfly, or a frog, we have to conjoin two different appearances. In reality, the stages of evolution are more frequently learned by seeing them -altogether on different subjects, — as in a plantation of trees, or in the mixture of all ages in human society. The evolution of living beings, plants, or animals, in their growth and decay, usually excites a strong and interested attention, which operates in fixing the successive stages in the recollection. The same produc- tion of interest occurs in historical evolutions ; and it is par- ticularly aimed at in the artificial evolutions of the drama and the romance. There is also a strong interest attached to the successive stages of a constructive operation — a pro- cess in the arts, a case in a court of law, or the course of a disease. A mind naturally adhesive to sensible impressions would, as a matter of course, acquire, out of its opportunities of observation, a large store of these successions ; but the bent of interest, concentrating the mind upon some, in pre- 29 450 EETENTIVENESS — LAW OF CONTIGUITY. ference to others, is the efficient circumstance. One man is engrossed with the progress of the field and the garden, from the seed to the fruit ; another looks with especial eye to the human development in body or in mind. The widely- diffused romantic interest stamps with ease the successions of a plot or a story. Apart from this circumstance of special interest in the unwinding of the future, the associations of evolution are not materially different from the conjunctions of still life ; these being also unavoidably successive in their presentation. The pages of a book, or the houses of a street, exist con- temporaneously, but cannot be viewed otherwise than successively. The mind formed to associate with little repetition the flowers of the same garden-plot, can likewise retain the different phases of the growing plant, 59. Relatiug to the recovery of trains of imagery, there is a fact of the nervous system to be attended to ; namely, that a mental movement once set on tends to persevere and feed itself. We can remark in the eye a tendency to continue in any motion when commenced — as in following a projectile, or in sweeping round the sky line that bounds a prospect. The spontaneous vigour of the moving organs carries them forward in any direction that they may chance to enter on ; and, in addition to the spontaneity of the active system, the stimulus of the sensation itself operates in sustaining a movement that has been commenced. Thus it is, that the eye so naturally follows out a vista, or traces the course of a stream. Seeing the beginning of a straight line, or a part of a circle, we feel ourselves led on to the conception of other parts hidden from the view. A tall spire carries the regards upwards far into the heights beyond itself, while a descending current gives a down- ward direction to the bodily or the mental eye. Just as we ac- quire an almost mechanical persistence in walking, or in handling a tool, when once under weigh, so the sight falls into a given movement, and goes on of its own accord, over the course that has been chalked out for it. When our eye sweeps along the line of a procession, it acquires such a persevering tendency that it is SUCCESSIONS OF CAUSE AND EFFECT. 451 apt to go beyond the termination until its view in that direction is completely exhausted. When a' succession of objects is very rapid, as in a railway train, it sometimes occasions a diseased persistency in the visual circles, and we feel everything about us still in motion. Like all the other actions of the brain, this persistency has a moderate and healthy pace, which easily subsides, and a hurried and diseased pace, which we cannot check without great difficulty. Now, in the operation of recalling the steps or members of a succession at the prompting of those that go before, our recollec- tion is aided by the tendency to go forward, or to leap from the one at present in the view, to the next in order. This restless forward impulse will not suffice of itself to recall the next member without an adequate adhesive growth between it and the preceding, but it counts for something in the act of recovering any object that we are in want of in that particular train. It determines very much the degree of rapidity of the mental action ; and, from this circumstance, gives a marked character to the individual. It does not confer intellectual power — this de- pends on the proper forces of the intellect ; but it favours prompt- ness and quickness in perceiving whatever it is within our power to perceive, — a quality often useful in the emergencies of life. 60. Cause and Effect. — As a mode of succession, this is characterized by some transition of a more or less startling kind. It also embraces a great many interests, from the fact that some important change may be aimed at by us ; and, accordingly, we desire to know the antecedent circmnstance that enables us to produce it. That the striking of a match will give a light and bring about ignition is not merely an impressive transition from its abruptness, but an item of practical knowledge treasured up in view of the exigencies of life. The case is, therefore, one of a visual or other sensible coupling, made specially impressive by the two circumstances named. Owing to the frequency and the range of such couples, we obtain through them a large contribution to our stored up knowledge ; and the case fulfils in the most ex- pressive manner the law of contiguity under the qualifying conditions enunciated at the outset. When a teacher is 452 RETENTIVENESS — LAW OF CONTIGUITY. specially eno;aged in conveying to pupils such knowledge, he is well aware of the vantage-ground that he occupies in securing its reception in their minds. The main device, in addition to the natural interest of the cases in hand, is to obtain for each example a moment of isolated attention ; it is only distraction of mind that can prevent one from readily imbibing sequences of clearly perceived causation. The foregoing statement is perfectly general. Under it, there are considerable and important varieties, although not constituting any serious difficulties in applying the law that we are discussing. Thus, we have the wide-ranging class of visible or tangible mechanical effects, which, numerous as they are, comply perfectly with the general statement just announced. There are more subtle transitions, known to chemistry and to physiology whose peculiarity is the occasional absence of that close and obvious transition that is so startling in a large class of mechanical effects. With due allowance made for such variations, the principles that govern the result are still the same. Our own exerted energies make up a very large region of our known examples of cause and effect. The obvious peculiarity here is the presence, in our own sphere of con- sciousness, of the antecedent circumstance. This ever- present antecedent is stamped on our recollection in a way peculiar to itself. As an item of knowledge, it comes with- in the sphere of what is commonly called self-consciousness : while all men are similar in the point of its being accessible to observation, they do not all agree in being equally atten- tive to its manifested display. This may make a difference in the pace of acquisition of the department in question ; while there may be also unequal susceptibility to the recol- lection of it, irrespective of stimulus to attention. Self- knowledge — in other words, the permanent record of our own states of consciousness, as distinct from our object experience — is a department by itself, as contrasted with object or sense knowledge ; and future chapters will, at various points, reveal the contrast. CAUSE AND EFFECT IN LIVING BEINGS. 453 61. There is still a variety of causation, where Hving and sentient beings occupy the place of consequent in the causal sequence. This is when the elfect, whatever it may be, consists in something done to a living being — man or animal. All the visible changes wrought upon the sentient creatures that come under our observation awaken our attention more or less, being calculated to stir up feelings of a variety of kinds, and of all degrees of intensity ; such feelings con- stituting the stimulants to our attention, and an aid to our recollection. Our stock of engrained knowledge of our own kind and of all creatures possessing sensibility and the means of manifesting it, is made up of causal experiences, of which the consequents are of this nature. The condition of impressiveness here is not so exclusively allied to self- attention as in the previous example. Our consciousness of self is merely an aid to the interpretation of an effect whose main aspect is purely sensible or objective. There now remains the class of examples where both antecedent and consequent are phases of living bemgs. A familiar instance is a contest between two men or animals. The varieties of the situation, however, are simply innumer- able. It is the region of human interest as spectacle, which surpasses in extent almost every other. History, poetry, more especially dramatic poetry, and fiction, are largely con- stituted by this pecuhar situation. The interest engendered by it leads to the easy and copious storage in the memory of the entire class of such incidents. The laws that regulate the acquisition are in no wise different from what have been already given under the two former heads. 62. Our impression of any individual man or woman is made up of their permanent image, and of their various move- ments and activity, in a number of situations and circum- stances. Thus, we have seen some one made angry ; we connect the occurrence with the experience of anger in our own minds, and this connexion is an item of our knowledge of that person's character. When the anger is brought before our view, we are reminded of the cause ; when the provoca- 454 EETENTIYENESS — LAW OF CONTIGriTY. tion is present, it recalls the anojer. We can use the know- ledge of this sequence for the purpose of either avoiding or bringing on the effect ; we can reproduce it dramatically ; we can generahze it as a fact of human nature ; we can explain other men's anger by it. Other sequences are noted in like manner ; and, by sufticient length of time and opportunity, we can associate cause and effect through the whole cycle of an individual's ordinary actions. We are then said to know the person's character. Our knowledge of animals is of the same nature. The peculiar susceptibility to the human presence now spoken of may arise out of several different sources. (1) To the natural history mind, all visible imagery is impressive, — • the human face and form among the rest. (2) The suscepti- bility to visible movements is a distinct element, and with it is connected the sense of forms — particularly, the human form. (3) The S3mipathetic disposition, as contrasted with the ego- tistic, or self-engrossed, is in favour of the same turn for noticing other people's ways. (4) The artistic sense finds much of its material in the human subject, and is thereby made alive to the manifestations of living men. To all these causes of special attention to the phenomena of humanity, we are to add (5) the strong passions and emotions that have our fellow-beings for their subjects : and we then see how it comes that the natural, if not ' the proper, study of mankind is man '. In the foregoing view, there has been no express mention of scientific causation. MECHANICAL ACQUISITIONS. We have now touched on the chief fundamental classes of associated things under Contiguity. What remains, is to carry out the illustration into the several departments of intellectual acquirement. 63. Under Mechanical Acquisitions, we include the whole of handicraft industry and skill, as well as the use of the bodily members in the more obvious and universal CONDITIONS OF MECHANICAL SKILL. 455 actions of daily life. Military training; the exercises of sport, recreation, and amusement ; the handling of tools in every kind of manual operation ; the care of the person, — are all so many acquired or artificial linkings of action with action, or action with sensation, through the operation of contiguous adhesiveness. The first element of Mechanical Acquisitions concerns the quality of the active instrument — the musdes. All the circumstances formerly described (p. 353) as special to the association of movements — Muscular Strength, Spontaneity, and Delicacy of Discrimination, — co-operate in promoting our muscular acquirements. The next thing to be taken into account is the delicacy of the sense concerned in the work produced. If the operation is to make a paste, or bring out a polish. Touch is the testing organ, and must have the requisite delicacy ; if the work is judged by colour, the Eye must be duly sensitive ; if to play on an instrument, the Ear must discriminate the shades of sound. However flexible and powerful be the active instru- ment, It can never transcend our conscious measure of the effect produced. The most delicate fingers are useless for musical performance, when the ear is wanting in a corre- sponding delicacy of musical perception.* Thirdly, we need to estimate the motives to concentrated attention. Of these, the chief is a taste, interest, or liking for the occupation itself ; and, next in order, must be ranked an agreeable end to be gained by means of it. The special fasci- nation for handicraft industry, manifested in some constitu- * As regards many kinds of mechanical manipulation, the muscular sensibility counts twice, being a property of the organ, and also a property of the sense. Thus, in handling a dough, or tightening a string, the sense concerned is muscular, and the nice graduation of the arm and hand to suit the desired effect is also a muscular discrimination. Hence, manual tact, or skill in working with tools or instruments, is doubly dependent on the muscular endowment. Even where the effect is judged, not tactually, or so as to bring in the sense of resistance, but by the eye, the ear, or the taste, the flexibility and measured graduation of the active organ involves the dis- criminative feeling of expended power, which attaches to the muscular sj'stem, and is. no doubt, unequally manifested in different constitutions. 456 EETENTIVENESS — LAW OF CONTIGUITY. tions, is a mixed feeling. Part of it, however, — perhaps the largest part, — comes from the muscular and sensitive endow- ments themselves : when these are of a high order, there is apt to be an accoinpanying charm in their exercise. The mere possession of the elements of skill — the hand and the sense — makes it a pleasure to exercise them. This is not merely from the distinction of superiority (an added motive of no mean force) , but also from the concurrence of a certain amount of feeling with every considerable endowment. If we have a powerful and flexible active organ, we are grati- fied by its exercise. In like manner, as to the sense con- cerned, we cannot have a nice ear for musical pitch, such as would favour musical acquirements, without being suscep- tible to the pleasure of music ; and the same is true of colour. The remoter objects of the mind, involved in mechanical aptitude, are the pleasure of power in producing" effects, and the satisfaction of the wants and desires that are the final end of industrial occupation. Apart from the motives of subsistence and gain, there is, in many individuals, a con- siderable degree of interest in mechanical operations, attri- butable to the possession of the main aptitudes for the work. Gardening, carpentry, carving, and other mechanical arts, are adopted among the recreations of leisure hours, no less than music. Louis the Sixteenth's lock-making has a place in history. 64. We must now advert to those circumstances aiding mechanical acquisition that depend, not on the inborn peculiarities, but on the manner of going to work. This is the practical point. The practice of drilling recruits in the army may be taken as indicating the results of long experi- ence in one department of acquisition. The procedure at present followed may be described thus : — In summer the recruit is maintained at drill four hours in the day. One hour is taken before breakfast — six to seven a.m. A second, nine to ten ; a third, eleven to twelve ; and the fourth after dinner — two to three p.m. AVith the omission of the morning hour, the same times are observed in winter. The general DRILL IN THE ARMY. 457 considerations that require to be attended to in securing the maximum of efficiency would seem to be these : — In the first place, the moments of greatest bodily vigour and fresh- ness are to be selected. In the next place, the exercise ought not to be continued too long at a time : when the muscles and brain are once thoroughly fatigued, the plasticity is at an end ; nothing is gained by persisting further. Lastly, the lessons ought not to be too short : that is to say, a certain time is requisite to get the body into the set that the exercises require. Scarcely any exercise of less than half an hour's duration, will take a decided hold of the human system. To hit the mean between the period of thorough engagement of the organs in the work on hand, and the period of excessive fatigue, constitutes the practical judgment of the drill-master in every department. In the army, where the time of the learners is completely under command, the system of four daily exercises with inter- vals of rest and refreshment is chosen as the best arrange- ment on the whole : the mental distaste apt to be generated by occupying the entire strength of the system upon one class of operations, is not taken into account. In the discipline of early education in general, there is more variety of interest, and it is possible to occupy nearly half the day continuously upon the work. But the army system is the model, in circumstances where it is practicable to bring the pupils together, early morning, forenoon, and afternoon. The rule for the exercises of the learner is very different from the rule for the practised workman at his work. In this last case, long continued and uninterrupted application is best. But, in learning a new thing, the stress of the atten- tion very soon fatigues the brain ; so does the committing of blunders and false steps. Moreover, the organs unhabituated to an operation are less able to sustain it. When, however, the mechanical routine is perfect, and the parts are strengthened by long practice, it is better to continiie at work for a number of consecutive hours. 458 EETENTIVENESS — LAW OF CONTIGUITY. The youth learning a trade keeps the same hours as the workman, and is not treated as an army recruit or a school- boy. In his circumstances, the plan of proceeding is different. The apprentice, having gained some one single step, before taking another, goes on repeating that process exactly as a productive workman. His education is spread over a longer time, and is largely diluted with routine work. This alone makes his situation tolerable during the long hours of the working day. It is when the rate of acquisition is pushed to the uttermost, and actual production is disregarded, that the system of long intervals of rest is most necessary. Here, as elsewhere, the learner's progress is vitally de- pendent on the absence of any other engrossing passion or pursuit. This makes it of so great consequence to have a liking for the subject. VOCAL OR LINGUAL ACQUISITIONS. Mthough the acquisitions of the articulating organs, in speech and languages, follow the very same general laws as other mechanical acquirements, then- importance as a branch of human intelligence claims for them a special notice. I shall advert first to the vocal exercise of singing. 65. The acquiring of musical airs and harmonies by the voice depends on the Vocal Organs, and on the Ear, aided by certain Sensibilities that may be supposed to pass beyond the ear. As regards the Vocal Organs themselves, the conditions are those already stated for the muscular aptitudes generally. To the first and second conditions — Vigour and Spontaneity, — we must add, if not implied, natural Compass or flexibility. The third condition — the delicate Discrimination of degrees of vocal expenditure — is what most decisively operates in fine execution, as well as being the test of vocal retentiveness. Next comes the Ear, the regulator of the effects produced by the spontaneity of the Voice. With a view to music, as already noticed, the ear must be discriminatingly sensitive to pitch, and thence to harmonies and discords. This AETICULATE SPEECH. 459 sensitiveness guides the action of the voice, and reduces its wild utterances to regular modes productive of musical effect. We also take for granted that a discriminative ear will be a retentive ear, so far as the retentiveness depends on the quality of the sense. The enjoyment derived from the art is, as in other cases, a motive to the attention. The acquisition of Instrumental music may be explained by substituting, for the voice, the action of the hands or the mouth, other things remaining the same. It would not be difficult to apply a test to the musical adhesiveness of different persons, by fixing upon a corre- sponding stage of progress, and counting the number of repetitions necessary to learn a melody. 66. In Articulate Speech, we have, likewise, a case of vocal execution guided by the ear, but with some differences as respects both the action and the feeling. The power of articulating includes a new series of movements— those of the mouth ; while the nice graduation of the force of the chest and of the tension of the vocal chords, required in singing, is here dispensed with. The sensitiveness of the ear to articu- late sounds partly agrees with, and partly differs from, the musical sense. The first stage of speaking is the utterance of simple vowels, or of simple consonants with vowels attached, — as vx(, Ilia, 'pa, hum. The sound ' «A ' is probably the easiest exertion of the mouth ; the other vowels, e, i, o, u, would seem more difficult positions. The labial consonants, m, p, b, usually, but not always, precede the dental and guttural; the closing of the lips being a very easy effort. The dental letters, d, 1, t, n, and the gutturals, Z', g, are perhaps equally easy by nature ; the aspirates are more complex and diffi- cult. Of the vibrating sounds, the hissing action of the s is sooner arrived at than the burr of the r. For this last letter, / and tc are used — as Inn, wun, for rmi. Xew difficulties appear, in the attempts to combine two consonants into one utterance; as in syllables that begin and 460 EETENTIVENESS — LAW OF CONTIGUITY. end with a consonant. Some of these are found easier than others : mam is easier than man, and this than mug ; for the reason that it is less difdcult to combine two labials, than a labial with a dental or a guttural. The effect is seen in the word-compounds of all languages. There are two stages in the acquirement of articulate sounds : the first is the stage of Spontaneous utterances ; and the second the stage of Imitation. In both, the natural flexi- bility or variety of the organs must be coupled with delicacy of the ear for articulate effects, in order to make rapid progress. The joining of syllables and words into continuous speech brings into play a further exercise of the associating principle. AYe must, next, add the element of Intonation or Cadence. This is among the accessories of musical effect, having little in common with the principal circumstances in Music, — namely, pitch, with its harmonies, and time. In speaking, the voice rises and falls in pitch, but not with any nice or measured gradation ; the degrees of stress or emphasis, the alternate rise and fall, the descent and gradual subsidence at the close, — are among the characteristics of cadence, or the music of speech. A great susceptibility to intonation marks some constitutions ; when coupled with a flexible articula- tion, it is the gift of the elocutionist. The earliest acquisitions of the purely verbal kind — short familiar forms of speech, prayers, rhymes, and stories — are examples of pure verbal adhesiveness. They depend upon the circumstances contributing to verbal memory all through life. If we try to fix the probable order of importance of the several conditions, we shall have to place first the Articulate Ear, and next the Vocal endowment, as regards Articulation ; it being a rule of the constitution, for which there is abundant evidence, that the sensitive side of the cerebral organization is more receptive and retentive than the active side. The general conditions of Ketentiveness are assumed as usual. A suitable natural adhesiveness is presumed. The motives to Concentration are numerous and various ; but they relate principally to the subject- LEARNING THE MOTHER TONGUE. 461 matter, which will be adverted to in next paragraph. Apart from the matter, there may be great liking or enjoyment of articulate exercises ; for which the chief foundation would be the saine full development of voice and of ear, rendering them adhesive without regard to the concentrated attention. In remembering long poems, as in the case of the ancient bards (not the composers), in the kind of erudition ascribed to the Druids, in the power that some persons have of re- collecting long speeches by rote, and in great lingual ac- quisitions generally, we have examples of the mere verbal memory. It must also enter as an element into high literary power of every kind. In estimating the genius of Shakespeare, we should have to begin by assigning him a very large share of this purely verbal aptitude. 67. The acquisition of the Mother Tongue supposes, not merely the cohesion of strings of words heard and uttered, but also the association of names with things, or meanings. We associate the names 'fire,' 'table,' 'John,' with the objects themselves. AVe further associate groups of words — w^hole sentences and trains of sentences — with objects, situations, actions, purposes, feelings, and so on. This refers us back to the law of heterogeneous association (§ 32), whereby the adhesion between two things is ruled by the respective tenacity or persistence of each ; the strong pictorial mind, for example, being disposed to remember better the names of visible objects. Whatever contributes to the interest or impressiveness of the subject-matter increases the facility of remembering the names. The strain of diction is thus a clue to the things that have engaged and arrested the mind. Swift could have acquired the magniloquence of Milton, and Milton might have made himself thoroughly familiar (as he was, in some degree, in his prose) with the coarseness of Swift, so far as concerned mere verbal acquisition ; but their vocabularies were made up under their respective preferences for the subject-matter. In reading authors for the acqui- sition of style, it is of importance that the subject should itself be interesting : writers may be of the highest repute 462 EETENTIVENESS — LAW OF CONTIGUITY. as classics in the language, but, if their ideas have become obsolete or insipid, we are very little impressed by their diction or vocabulary. Written Language introduces the adhesiveness of the eye for Forms — a very powerful adjunct in verbal memory; being an important aid in the mother tongue, and a principal bond of adhesion in the scholarly recollection of languages. 68. In acquiring Foreign Languages by the usual methods, we have more of the purely verbal associations than in the ixiother tongue. We do not usually connect the names of a foreign language with the objects, but with the names already learnt. We may connect sound with sound (as when we are taught orally), articulation with articulation, or mark with mark to the eye. Thus ' domus ' and ' house ' may be asso- ciated as two sounds, two articulations, or two sights; usually, we have the help of all three ways of linking. If we include the act of writing down words, which embodies them also in the nerve centres of the arm and hand (besides concentrating the eye), there are no less than four lines of adhesion, m- volving two senses and two modes of mechanical exertion. In the absence of a good contiguous adhesiveness for indifferent objects, such as arbitrary sounds and symbols, lingual acquisitions are necessarily laborious and difficult. 69. Oratorical Acquisition introduces the element of Cadence. This is partly created in ourselves by the spon- taneous flow of voice becoming modified, to please each per- son's own ear ; by which means we have originality of cadence, whether the quaUty of the creation be high or low. But, for the most part, it is acquired by hearing others, like vocal melodies. Many forms of cadence prevail in human speech. Each nation has characteristic strains of this kind : the foreigner, however perfect in the pronunciation of the words of another language, is detected by the absence of the national manner in his spoken melody. Provinces differ in the same country : English, Irish, and Scotch have their peculiar strains. The orator is a man able to produce a great variety of the richest cadences, just as a singer has the command of ELEMENT OF CADENCE. 463 many vocal melodies. To lit articulate language into the forms and falls of musical articulation is the orator's art. We have no artificial means of expressing or representing the oratorical rh3^thm, so as to preserve the manner of a great orator, or to mark the differences betw^een one cadence and another ; the notation of the elocution manuals is not carried far enough for that. But we can readily specify the general conditions of oratorical acquirement. The abundant and various action of the voice by primitive con- stitution, the susceptible ear, the opportunity of hearing many and good varieties of the elocutionist's displays, and a strong sustaining interest in this particular effect, are the essentials ; a good general adhesiveness concurring. Cadence, although properly a spoken effect, is transparent through written composition. In pronouncing the language of Johnson or of Milton, we fall into a distinct strain : this, too, we can acquire and impress upon compositions of our own. We naturally drink in such cadences as are most suitable to the natural march of our own vocal organs, and such as possess th-a greatest charm. The Metrical form of language imparts a special pleasure to the ear ; and most minds are disposed to remember by preference composition in verse. As illustrative of remark- able metrical susceptibility — Pope ' lisp'd in numbers, for the numbers came '. RETENTIVENESS IN SCIENCE. 70. By Science, I here understand the artificial sym- bolism and machinery, requisite for expressing the laws and properties of the world, as distinguished from the actual appearances of things to the common eye, — of which I have already spoken under the heads of natural conjunctions, successions, etc. Thus, a treatise on Astronomy is a mass of algebraical calculations and numerical tables. Nothing can well be more unlike the aspects of sun, moon, and planets, than the formulae and tables expressing the scientific relations of these bodies. 464 EETENTIVENESS — LAW OF CONTIGUITY. The Object sciences range from the extremely abstract and symbolical — such as Mathematics, where nature in its ob- vious guise is utterly excluded — to the more concrete subjects of Natural History, wherein some part at least of the acqui- sition consists in storing up the common appearances of animals, plants, and minerals. The conditions of the ac- quirement differ, according as any branch is nearer the one or the other extreme. Thus, theoretical Mechanics, As- tronomy, and Optics, come under the mathematical class. The experimental parts of Chemistry, Physiology, Anatomy, approach the other end of the scale : in these, the ad- hesiveness of the natural history mind for sensible appear- ances and properties, is of the highest consequence. To advert to the more abstract sciences, which represent science as most opposed to our unscientific images and notions of the things about us. The symbols of Arithmetic and Mathematics in general, the symbols and nomenclature of Chemistry (combining proportions, atoms, etc.), the nomen- clature and abstractions of Physiology (cells, corpuscles, ultimate fibres, secreting glands), require a peculiar cast of intellect for their acquisition ; and they are so far of a piece that the mental adhesiveness suited for one would not be much at fault in any other. They are a collection of bare forms not remarkably numerous, which are to be held in the mind with great tenacity, and to be accepted as the sole representatives of the phenomena. The self-denial that enables us to dwell among algebraical symbols, con- centrating the force of the brain upon them, to the exclu- sion of all those things that gratify the various senses and emotions, — this abnegation, so to speak, of human interest, is the moral peculiarity of the mathematician. It is not necessary that the mathematical mind should be entirely destitute of attraction for colour and beauty, and picturesque- ness, and music ; but it is necessary for such a mind to cast all these out of the view, and to grapple with the artificial symbols that express the important truths of the world. The interest in attaining the sure and certain laws of the ACQUISITIONS IN ABSTRACT SCIENCE. 465 universe, is the motive for immersing the mind in such a cheerless labyrinth of uncouth characters. This motive being once strong in an individual, the other chief requisite is great natural adhesivenessfor arbitrary symbols, — an adhesive- ness that, if depending on local causes, results, in a consider- able measure, from the moderate degree of the competing sensibility of the eye — the feeling of Colour. The symbols of a science are few in comparison with the words of a language ; but the hold of the one must be much more severe than of the other. A circle used as a diagram in Euclid, must make a deeper impression than a circle as an alpha- betic letter. With Euclid's circle has to be associated in- numerable lines and constructions, which can never be all presented to the eye at one time, but must be firmly held in idea alone, ready to be brought up on the hint being given. To the alphabetical circle, there is no such array of ideal appendages ; it is conceived simply as it can be written, and only as regards its visible difference from the other letters of the same alphabet. It is this complication of visible figures, with a multitude of associates not possible to exhibit at once to the eye, and which yet must all be at command, that gives such an intellectual character to scientific reasonings. The Geometrician must retain, in connexion with a circle, all the constructions of Euclid's Third Book, and, if need be, all the constructions that precede and give foundation to these, and, likewise, the language that represents in words what cannot be presented to the eye ; all which puts to a severe test the cerebral adhesiveness for uninteresting forms. Moreover, this ad- hesion must rapidly get firm at every step, otherwise the earlier steps of a deduction would be lost before the later were fixed. In an algebraical problem, where x is put for one thing, and y for another, the learner must, by the force of a single repetition, remember all through that these letters stand for such and such things. Persons not rapidly im- pressed with these arbitrary connexions, are unqualified for mathematics. 30 466 EETENTIVENESS — LAW OF CONTIGUITY. In Arithmetic, the ciphers, their additions, subtractions, multipHcations, and the decimal system of reckoning, are of the nature of associations of symbohcal forms, and require the firm concentration of the mind upon arbitrary signs for the sake of the end they serve. In Algebra, the same opera- tion is carried to a higher complexitj', but without any dif- ference in the nature of the machinery. In Geometry, a host of definitions have to be remembered ; that is, a hne, a space, a square, a circle, must be associated with certain other lines and constructions, with the assistance of lan- guage. ' A circle is a line equally distant from a central point.' The association here is between the visible aspect of the circle, with its central point, and a line drawn from the centre to the circumference ; which line is a representa- tive line, and may be drawn anywhere round the whole compass of the figure. This principle of representation is a thing of the intellect entirely; for, in addition to the sensible object, there is a fact, or a multitude of facts, that cannot be made apparent to the eye at one and the same moment. In the ex'perimental and concrete sciences — as Heat, Elec- tricity, Chemistry, Anatomy, and Natural History in general, — the consideration of the actual appearances to the senses mixes largely with the artificial symbols and abstractions ; and hence the value of a good adhesiveness for colour and shape, for touch, and even for taste and smell, in storing up the objects of those sciences. The Mathematical mind may be quite at fault here, just as the Natural History mind is apt to be unsuited for the mathematical group of subjects. In Anatomy, for example, there is a vast detail of bones, ligaments, muscles, blood-vessels, nerves, etc. ; and the visual adhesiveness for mere colour is an element in the recollec- tion, as with a map, or a pictorial landscape. The tactual adhesiveness is of some value in this class of objects, and in the various objects of the natural history class — minerals, plants, and animals, all which are handled as well as seen. Thus it is that there are, for the Object sciences, two classes of scientific minds, represented by the extreme terms. EXPERIMENTAL AND CONCRETE SCIENCES. 467 Mathematics and Natural History — the abstract or artificial, and the concrete or real. As regards the modes of human interest or fascination, a greater number of classes could be made out : pure mathematics, as in Algebra and Geometry, would have a different set of votaries from mathematics applied in Mechanics, x\stronomy, Optics, etc. ; and the natural history group would be both separated from experi- mental Physics and Chemistry, and broken up into its component members, Mineralogy, Geology, Botany, and Zoology. 71. In the next place, as regards the Sub.ject world, we have one comprehensive science, termed Mind, Mental Science, Mental Philosophy, Psychology, etc. Although the science of mind comprehends many pheno- mena of an object character, — namely, all the outward or observed accompaniments of mind, and all the outward dis- plays of human action, thought, and feeling, — it is, nevertheless, essentially based on the consciousness possessed by each of our own mental states. The taking cognizance of the facts of our own mind, as phenomena to be known and studied, is one of the meanings of the name ' consciousness '. A better designation is self-consciousness, or the power of introspection. Locke applies the name ' Reflexion ' to this operation ; it has also been called the Internal Sense, because it is, to the subject world, what the External Senses are to the object world. There is, in some individuals, a special aptitude for this department of knowledge. An abundant recollection of sub- ject states — of feelings and ideas considered as to their mental sequences — is necessary to the mental philosopher, and is of value to all persons requiring a knowledge of mind for their respective vocations ; among whom we may instance the poet, the novelist, the historian, the orator, the politician, the teacher, the preacher. It is no easy matter to lay down the precise intellectual conditions of the special retentiveness for the phenomena of mind. We have not here the advantage of a distinct orgfan to appeal to, as with the pictorial memory, or the musical 468 RETENTIVENESS — LAW OF CONTIGUITY. memory ; and yet it is an indisputable fact, that feelings and the successions of ideas, considered as knowledge, are better discriminated, identified, and remembered by some men than by others. A good general adhesiveness, coupled with a motive to concentrated attention on the laws of mind, would obviously go a considerable way. But, if we are further to inquire into the circumstances that confer a select and special power of retaining subject states in the memory, — like the susceptibility to colour applied to the recollection of visible images, — we have only negative conditions to appeal to. Given a certain plastic energy of the mind, that energy will be directed, either upon the object world, or upon the subject, or upon both, in varying proportions. If there be an almost exclusive bent towards the outward, there will be the minimum of attention paid to the inner world of the subjective consciousness. If the outer world attracts us in only a moderate degree, there will be large surplus of force available for the other. Now, it is not difficult to assign the forces and dispositions that constitute our Object regards. They follow strictly the object side of our being, — namely, movement in the first instance, and, in the next, those sensations that, by connecting them- selves closely with movement, are looked upon as object properties. Perhaps the foremost circumstance inclining to the objec- tive point of view is a great endowment for muscular action in all its forms. In some minds, the forces of the system are profusely inclined towards bodily movement, and activity. This induces a preponderating object attitude, and a corre- spondingly reduced subject attitude. A certain share of subject existence must fall to every sentient being: pleasure and pain must always be recognized and acted on. But the subject existence may amount to little beyond pleasure and pain, as motives to the will. That further tendency, of making these a matter for study and reflexion, will be pre- vented by the intense proneness to bodily movement. When the outward prompting is less than ordinary, the purely SUBJECT SCIENCES — KNOWLEDGE OF THE MIND. 469 subject existence occupies a larger space ; the feelings and ideas, being more attended to, are better known and remem- bered. It is well known that when bodily vigour is high, and the disposition to exert it correspondingly great, self-conscious- ness in all its forms is at a low ebb. Obversely, advancing years, sickness, and confinement of the energies, throw the mind upon itself and bring forth the points of introspective regard, in the shape of greater knowledge of the human feel- ings, more sympathy with others, a moralizing tendency, and ethical self-examination. Next to the disposition towards bodily energy, we must rank, as anti-subjective tendencies, the sensations of the leading object senses, — as Sight, Hearing, and Touch. A strong sensibility to colour, to form, or to articulate utter- ance, operates in the direction of object regards ; if those sensibilities are only average, or below average, in a mind of great compass, a large share of attention will fall upon the subject states. We can never extinguish the object regards: when, as sometimes happens, they are too low for the purposes of mental study, the mind must exemplify its powers by working in the object attitude, in order that we may study these powers. The subjective mind is more than usually alive to its organic states, — which have very little object reference. These feelings direct us mostly to the body itself, which is no doubt an object, as being a part of the extended, but, in contemplating it, we are not led out of self in the same decided manner as in viewing other objects. Indeed, by fix- ing the gaze on our own sensitive parts, we may produce a new subject sensibility, owing to the associations that con- nect them so strongly w'ith our feelings.* * The tendencies of theniind towards sensation, or the actual, are opposed to two things, both included under one name, Reflexion. A person may be given to Reflexion, in the meaning of contemplation or meditation, on the matters of the object world. According to this meaning, every man that thinks seriously on anything must practise Reflexion. It is by reflecting 470 EETENTIVENESS — LAW OF CONTIGUITY. BUSINESS, OR PRACTICAL LIFE. 72. In the higher departments of industry, or business, — handicraft labour being the inferior department, — the forces of the intelHgence have a wide scope, the widest next to pure science. In the formahties and machinery of business, — book-keeping, calculation, money-reckoning, banking, con- tracts, deeds, acts of Parliament, etc., — we have a number of dry artificial elements, not unlike the machinery of the abstract sciences, but touching more closely and frequently upon things of universal interest. In fact, the superior branches of industry — commerce, manufactures, govern- ment, etc. — seem well adapted for the great majority of the cleverest minds. The pains averted, and the gratifications procured, by wealth, are so various and powerful, as to stimulate strongly the mass of human beings ; while only a very few can ever be possessed with the love of truth in the abstract, as a dominant sentiment of the mind. 73. The management of human beings, which is a large department of practical life, proceeds partly upon certain active qualities, that give a natural influence and ascendancy over others, and partly upon a knowledge of the ways and tempers of men. Without such knowledge in considerable measure, the master of workmen, the teacher, the legislator, and many other professions besides, can hardly be said to be skilled in their craft. It requires a kind of observation rendered difficult by the very causes that make man inter- esting to man ; for, those passionate feelings that arrest our gaze upon our fellows sway the- mind from cool judgments. beforehand that we save ourselves the trouble of actual trials in many- instances. The unreflecting and active temperament would prefer the trial. A mathematician, a physiologist, a politician, an engineer, a general, a poet, must reflect a great deal ; having a certain acquaintance with the facts of the outer world, they must think over those facts in combining them anew for their several jjurposes. The other meaning of Reflexion (the meaning in Locke) is the intro- spective, or self-conscious regards, as now described. Sir W. Hamilton would call it the Presentative Faculty for the knowledge of Self (see Note G). HIGHER DEPARTMENTS OF IXDUSTRY. — FINE ARTS. 471 It is not SO easy to read accurately a man or a woman as it is to read a mineral. A person engacred in any work should naturally be alive to the end; for this it is that guides his hand: the builder sees that his wall is rising plumb and square. But, in acting upon men in the various capacities of teaching, ruling, persuading, pleasing, ser\ang, we are not so sensitive to the exact result of our attempts as in dealing with the material world, nor so ready to adapt our movements to suit the end in view. ACQUISITIONS IX THE FINE ARTS. 74. In the Fine Arts, there are produced combinations,, aggregates, groupings, rhapsodic successions, — such as to yield the species of effect termed beautiful, sublime, pic- turesque, harmonious, etc. ; and the perception of those effects is Taste. The artist in any department has to attain the power of producing these combinations. This power is, at the first start, a result of creative spontaneity, guided by the sense of the effect produced ; it is a mode of the natural forth- putting of the energies of the voice, or the hand, as in the commencement of every kind of active faculty. The first musician gave scope to his vocal powers at random, and gradually corrected the action according to his ear. When this natural outburst took some definite and agreeable shape, it became a song, a melody, caught up by imitation and handed down to future ages. A large part of every artist's power necessarily comes by acquisition, that is, by the operation of the force of Contiguity. He stores up the combinations produced by previous artists, and fixes in his mind those that he produces himself, and gradually rises to his highest efforts of execution. In this acquisitive process, the conditions appear to be the following, — of which, however, the enunciation is not altogether new to the reader. (1) A keen sensibility and adhesiveness for the element or the material that the artist works in. The musician's ear 472 EETENTIVENESS — LAW OF CONTIGUITY. must be sensitive to sounds and successions of sound, — by which circumstance he is able to acquire a large stock of melodies. The sculptor must have a keen sense of contour and form ; the painter, of form and colour ; the actor, of dramatic movements ; the poet, of language and the usual subjects of poetry. (2) In addition to this sensitiveness to the material of the art, there falls to be noted the special sensibility to the proper effects of the art ; the sense of melody and harmony in music, of beautiful curves and proportions in sculpture and architec- ture, of these last, with coloured effects in painting, and so forth. I take for granted that beauty is not arbitrary, — that there are effects that please mankind generally. For these the artist has a marked preference, and, by virtue of such pre- ference, he acquires a stronger hold of what causes them, than of what does not. The poet needs a large disinterested adhesiveness for the concretes of nature and the incidents of humanity ; but with this alone he would be indistinguishable from a born naturalist : the disinterested adhesiveness must be qualified by a special fascination for things that have a poet's interest, so as to alter the proportions of his impressi- bility, and give the preponderance to one special class of appearances. Not all trees, and all mountains, and all vegetation, and all displays of human feeling, should im- press alike either a painter or a poet. (3) An artist is to a greater or less extent a mechanical workman, and improves in his art according as he attains to the requisite mechanical operative skill. The singer, the orator, the actor, must cultivate the voice. The painter and the sculptor are persons that would soon learn any handicraft operation of the artizan's workshop. The poet, however, like the abstract thinker, may dispense with this muscular element of character. HISTORY AND NARRATIVE. 75. The successions of events and transactions in human life, remembered and related, make History. A considerable MEMORY FOR HISTORICAL TRANSACTIONS. 478 portion of each one's stock of recollections is made up of such materials. The transactions and events that we ourselves have borne a part in, impress themselves on the mind as pictures of living- men and women, their various manifestations, and the appearances and situations of things about them. It is thus that we retain the impression of a public assembly, a military spectacle, a pageant, a play, or any of the daily on- goings of private society or of ordinary business. The pictorial mind is fully alive and susceptible to such things, and is tested by retaining them. The retentiveness is heightened by the general interest in human beings, and by the specific or personal interest that belongs to the trans- actions. The soldierly feeling fixes the mind upon battles, reviews, and military movements ; the trader is arrested by markets and commercial enterprise ; the politician wakens up to diplomatic congresses and debates ; the sporting mind is alive on the race-course ; the family interest excites the attention upon the incidents of the domestic circle. A single transaction deliberately witnessed is often able to stamp itself in the memory for life. There seems to be, in the case of human events, an exception to the law of Repetition, or to the usual necessity for passing a thing before the mind many times in order to make it coherent. But we are able to account for the seeming anomaly. For, in the first place, such transactions are usually slow ; that is, they keep the attention awake for a length of time before they are completed : a single horse race, if we include the preparations, will engage the mind for an hour together ; while some transactions occupy days and months, being the subject of frequent attention all through. But, what is more, many past events are frequently brought to mind ; and every such occasion is a mental repetition. After being present at an exciting spectacle, our thoughts keep themselves engaged upon its details ; and, in the retrospect, we expand our attention upon things that were but hurriedly glanced at as they passed before the actual view. Such 474 RETENTIVENESS — LAW OF CONTIGUITY. rehearsal in the mind, after the reahty has passed, is a great means of impressing the events of our personal experience. The degree of emotional interest attaching to them displays its efficacy in bringing about their more or less frequent recall. AVhat is indifferent passes away — it is rarely dwelt upon afterwards ; what has excited us at the time excites us in the remembrance, and secures a large space in our ideal meditations. Provision is thus made for consolidating in the memory a train of circumstances that do not admit of being repeated in the actuality. We are enabled to recall, in after years, all the leading transactions that are now going on around us : we can describe the incidents connected with our family, our village, our city, our school, our places of business, recreation, or worship ; we can hve over again, in minute detail, the scenes that had an intense pleasurable or painful interest at the time. 76. The transactions that we know by hearsay, or the narrative of others, impress themselves somewhat differently. We have no longer the actual scenes presented to our vision : they are represented by words, and the recollection is modi- fied by the circumstances affecting verbal adhesion. If we make the extreme supposition, that the hearer of a narrative has his mind carried at once to the scenes and events them- selves, and is able to realize them with an almost living force, the case is not different from the foregoing ; the words are made use of to hoist the scenes, and then drop away. But there are few people that have this vivid power of conceiving the realities of narrated transactions. In general, the verbal succession of the narrative is itself the medium of holding together the events contained in it, and the recollection is a mixture of adhesions, pictorial and verbal. Written history may, therefore, be retained by a good verbal memory. When the thread of pictured events has snapped, the thread of verbal succession in the printed page may suffice ; the power of recollection on the whole is ir- regularly divided between the two. EECOLLECTION OF OVR OW^' DOINGS. 475 OUR PAST LIFE. 77. The train of our Past Existence, as a whole, is made coherent in the mind through contiguity, and can be recalled with more or less minuteness according to the strength of the adhesion. In any subject that is complicated with details, only a few prominent features usually cohere — as, for example, the striking parts of a landscape, or incidents of a history ; and such is the case with the great complex currents of each one's individual existence. This current is made up of the elements contained under the foregoing heads of this chapter. It embraces all our actions, all our sensations, emotions, volitions, in the order of their occurrence. It is the track described by each indi- '^adual through the world during his sojourn therein ; it comprises all that he has done and all that he has been impressed with. Under the previous head, I have spoken of the stream of history, or the current of events passing before the eyes of a spectator supposed to be passive. But spectatorship of what is going on about us, does not express the whole current of our remembered existence ; there is wanting the series of our own doings and transactions. When what we have done is added to what we have seen and felt, the history of self is complete. The distinguishing feature of the present case, therefore, is the remembrance of our own actions according as they happened. What is the nature of the bond that cements things done by us, and not simply witnessed ? 78. In the first place, many of our movements consist in changing the spectacle about us, or in producing a series of appearances to the eye, or of effects on the senses in general. Thus, when we walk out, we bring before our eyes a stream of houses, shops, streets, fields ; and the impression of the walk, — the coherent trace that it leaves in the brain, is, in part at least, pictorial, just as if we stood still and saw the scenes shifted in the same order. So, our work often con- 476 RETENTIVENESS — LAW OF CONTIGUITY. sists in producing changes, seen and remembered, as sensible appearances. The ploughman's active day is partly summed up in the furrowed field that is pictured in his mind in the evening retrospect. Hence remembered actions may be to a great extent remembered appearances. So far, the case now in hand is in no way different from the preceding. It is evident, however, that there must be a remembrance of actions by themselves, as well as of the changes that they bring before the view. We do, in fact, have a recollection of our own active states as such ; we can describe the move- ments made by us, the feelings of pleasant exercise, laborious exertion, or reposing fatigue, that we have successively gone through in a given day, week, or month. This takes us back to what was laid down, at the com- mencement of the present chapter, on the Ideas of movement and action. I endeavoured to show that these are formed by re-actuating the circles of movement, but so as to come short of the full stimulus required by the action itself : the re- membrance of striking a blow is in reality all but to repeat the act ; the restraining of the full display being sometimes a considerable effort. Now, successive actions cohere both as actions and as ideas ; we may either perform an action out- right, or stop short at the mere idea or vestige of the action. Much of our life is spent in going over remembered and ideal actions ; and, when we recover a work done by us, merely as a matter of history, and not for the purpose of doing the work again, the vestige, or idea, of the different steps is what passes along the mental tracks. These vestiges of movement exe- cuted are as really and truly mental possessions, or ideas, as the remembered pictures of the external world through the eye. We can revive one or other in the ideal form ; and, in- asmuch as our sensations are all unavoidably mixed up with movements, our recollections are usually a mixture of the two. Now, in recalling a series of movements — as, for instance, a dance — simply for our own gratification, because of the agreeable feelings that they gave in the reality, we do nothing but revive those vestiges or diminished currents that suffice MENTAL EMBODIMENT OF EEMEMBEEED ACTIVITY. 477 for the purpose of a recollection. This is to live our history over again in idea. And, when we have acquired the power of naming all the various movements in succession, the ideas, as they successively repossess the various organs, suggest the names of the different steps, and we can then narrate the whole in language. It is this power of narrating that we usually term the recollection of an event, and that constitutes history. With the power of language that belongs to human beings, it happens that our recollections of what we have gone through, do not occur as pure ideas of the actions and scenes themselves, but as ideas mixed up with verbal descriptions ; which last are constantly disposed to intrude themselves into our recollections, even when these are not communicated to any one. The firm adhesion of the ideas or vestiges of our active movements is acaseof muscular contiguity, like the adhesion of the actions themselves in acquiring mechanical habits. I cannot find any other law for the association of ideas of movements than for actual movements. I have already endeavoured to discuss the circumstances favourable to the adhesion of muscular trains, and these would, I conceive, hold in the present case also. People that have a facility in acquiring mechanical habits, would, in general, have an equal facility in remembering the steps of any performance that they had gone through. The greater instance imphes the less ; the adhesion of the movements in full involves the adhesion of the currents that stop short of movement. The case is altered, as already remarked, by the intrusion of language or expression : in so far as we rely upon this, our remembrance will be easy or difdcult according as our adhesiveness for language is strong or feeble. This is not the only instance of impressions retained by the help of some foreign machinery more adhesive than themselves. We have seen the same thing in the retention of the sensa- tions of the inferior senses. 79. Our past life may, therefore, be conceived as a vast stream of spectacle, action, feeling, voHtion, desire, — inter- 478 EETENTIVENESS — LAW OF CONTIGUITY. mingled and complicated in every way, and rendered adherent by its unbroken continuity. It is impossible, however, to associate equally all the details, so as to recover them at pleasure ; only the more impressive facts remain strung together in recollection. The larger epochs and the stirring incidents readily come to our recollection, when we go back to some early starting-point ; while the minor events fail to appear on the simple thread of sequence in time, and are recalled only by the presence of other circumstances that serve to link them with the present. It is our custom, in recalling the past, to string together events in new con- nexions, as when any one recites the history of their early education, selecting out of the miscellaneous stream the inci- dents relating to that one point. Our individual history becomes thus broken up into sections and partial narratives ; and, to recover the total current, we should find it requisite to collect these into one great sequence, upon the thread of strict succession in order of time. 80. I have thus presented a series of examples of the working of the Retentive, or adhesive, property of the Intel- lect. As the subject proceeds, there will be other oppor- tunities of adding to the illustration. The special branch of Moral acquisitions, or Habits, wdll best find a place in treating of Volition. There now only remain some general observations on the nature of this great adhesive force. First. Throughout, we have assumed superiority in ac- quisition to depend partly on general conditions— Repetition, Concentration, and the Adhesiveness of the mind as a whole ; and partly on special or local endowments. The only doubt- ful point is the relative shares of the general adhesiveness, and of the local endowments of the senses and moving organs. There is, certainly, a presumption in favour of a contrast, from the essential difference between sense and in- tellect, notwithstanding their intimate connexion and depend- ence. Anatomically, the two are thought to be separately QUESTION AS TO POWER OF GENERAL ADHESIVENESS. 479 embodied ; the senses being more related to the gangha of the brain, the intellect to the convoluted hemispheres. Besides, there are individuals distinguished as learners generally : they may not succeed in all subjects alike, but they have an aptitude for acquirement so extensive as not to be properly referable to endowments of the special senses. When we find a man almost equally accomplished in mecha- nical art, fine art, language, science, business, we regard the case as coming under general retentiveness, and not under an aggregate of high sense-endowments. Lastly, many of the lower animals, as the dog, have sense-endowments of the first order. If we judge these by the proper test of a sense — delicate discrimination, — they will bear comparison with human beings, even in Sight and in Hearing, not to mention their superiority in Smell. That their powers of memory in some degree correspond, we may presume, although we may not bring it to an actual test. Ferrier playfully re- marked of the dog that, if two met together in the evening to compare notes, they would put it one to the other in the form, — What have we smelt to-day? In the second place, I may advert to the known superi- ority of early years as regards this force or plasticity. It is not easy to state with any precision the comparative in- tensity of the adhesive growth at different ages, but there can be no doubt of the fact of its gradually diminishing from childhood to old age. Bodily acquisitions are easiest while the organs are still flexible, apart from the plastic adhesive- ness of the brain ; hence, a maximum age is fixed for admit- ting recruits into the military service. At the present time, I believe the age of twenty-three is the extreme term of admission. Uj) to this age, any bodily habit is easily as- sumed ; the moral discipline of obedience is also compara- tively easy. But, for both the one and the other, the earliest years are the best. We must always take account of the obstruction arising from adverse bents and acquisitions. In matters where the bodily and mental system are not pre- occupied, the age of twenty-five is a very plastic age, — as, for 480 RETENTIVENESS — LAW OP CONTIGUITY. example, in learning business-forms, languages, or science. On the other hand, the voluntary command of the attention is greatest in more mature life. Special Circumstances Governing Recuperation. — The force of retentiveness, as above stated and conditioned, has its final test and perfect fruit in due recovery under the proper cir- cumstances. In other words, when the first member of an associating couple is presented to consciousness, the second appears as a matter of course. If such were not the case, we should have to pronounce that the link of association had been insufficiently forged ; that some of the requisite conditions had been wanting. All this, however, proceeds upon the assumption that the bodily and mental framework at the moment of the associating recall is in a fairly average normal condition. 1. Physical conditions. It may be fairly assumed that the bodily state already described as favouring the first reception and steady growth of associated products, is also the state favourable for reproduction when required. In the first learning of a lesson, it is proper and suitable that the organs should be vigorous and the attention fully en- gaged. It is equally fitting that, when the time comes for repeating the same lesson, the learner should be as nearly as possible in the like condition. A task that can be perfectly well performed in ordinary circumstances, as respects physi- cal soundness and available attention, may utterly miscarry under an altered state of things. It is notorious that morning freshness enables a learner to execute a stroke of memory or reproduction that is found impracticable at the end of the day. So, in a condition of unusual bodily exhaustion, memory refuses to respond even in some of our most secure acquisitions. Practically, this circumstance is equally important at the moment of learning and at the moment of reproducing or remembering. It does not follow that we should adopt Hamil- ton's Beprod active faculty as something distinct from a Gonserva- CIRCUMSTANCES CONNECTED WITH RESUSCITATION. 481 tive faculty. The storing of the mind is one undivided fact, although involving a variety of conditions. It is not enough to look to the circumstances attending the first impressing of an idea. We need also to take an account of the circumstances attending its resuscitation. Still, these last circumstances do not involve the assumption of a distinct faculty. The extreme illustration of the importance of the actual condition of the bodily system at the moment of revival is to be found in the recorded instances of extraordinary force of memory under febrile excitement. It is not uncommon for patients in such a state to remember trains that formerly passed through the mind, but were never sufficiently en- grained to reappear under an average condition of the nerves. 2. Antecedent situation fully given. The recovery of a train by association assumes that the full and complete antecedent shall be supplied. The meaning of this is, that the first member of a couple or a series may not be suffi- ciently expressed by assigning the more obvious or prominent item. For one thing, it is well known that the same object of thought — a sound, a name, a visible thing — becomes the starting-point of many different trains. A musical note struck does not resuscitate in the mind of a musician any one air ; it being common to a great many. It must be followed by a second and a third and a fourth, until the concurrence points to one definite air and no other. So with language. The first word of a known passage suggests nothing. The word ' the ' commences so very many com- positions that it recalls none. Add a second word and the number of outlets undergo a certain amount of limitation, although as yet perhaps not reducing the number to one alone. In all cases, therefore, of recovery by association, the first requisite is to complete the group of elements that hems in the associative succession to one channel. When this is not done, either there is no associative reproduc- tion or there is more than one, or some casual addition at the moment determines the cause of the resuscitation. 31 482 RETENTIVENESS — LAW OF CONTIGUITY. 3. Readiness of suggested circumstance to arise. Ir- respective of the strength of the associating link, and the completeness of the prior situation, is the readiness of the suggested circumstance to appear owing to something in its own nature, whether permanent or temporary. The most striking instance of this, perhaps, is the case of an idea suggesting a name or verbal delineation. When the verbal element happens to be strong, whether as a feature of the character, or as being fresh at the moment, the utterance of the name or verbal description is stimulated in an unusual degree. Moreover, when the act of utterance is foreseen to be gratifying, it is prompted by that consideration. The fact will afterwards be noted that, in the springing up of thoughts, there is a moment preceding the full conscious recovery, when the tone or character is so far anticipated as to encourage, or else discourage the perfect resuscitation. 4. Plural associations. It often happens that an as- sociative link is not sufficiently strong to operate in ordinary circumstances, — there being a great many such insufficient bonds in our educational history, — while by the concurrence of some second associate, also perhaps insufficient in itself, the recovery may take place. This is a fact of sufficient im- portance to receive a full exposition at a subsequent stage (see Compound Association). 5. Eecency. The element of recency is well known to count largely in the facility of recuperation. This however is a wide ranging topic. It is incorporated with the essen- tial condition of consciousness — its limitation at any one instant — and the mode of overcoming this limitation so as to perform the more complicated operations of thought. Also, m deciding the question as to the period when an acquisition may be regarded as settled and permanent, as beyond the power of decay, we must take note of the continuance and repetition of the supposed exercise, and the circumstances that accompany this repetition with a view to the result (see note C). Gradation of adhesive intensity. — The rate or pace of re- FAILUEE OF MEMOEY. 488 covery of foregone trains by association is known to be ex- tremely unequal, even when sufficient for the purpose. The effect of very great iteration is, we are aware, to quicken the pace of recovery, while reducing the strain of conscious- ness accompanying the act. A familiar example is the difference between speaking our own language and speaking a foreign language that we may have sufficiently learned for all practical purposes. It is a further consequence of ex- treme iteration that recovery takes place in circumstances of depression and failure of the bodily and mental powers. Likewise, the release of conscious attention in such higher forms of habituation permits the occupation of the mind with some other train of actions or thoughts. We have thus, in connexion with the higher degrees of associat- ing iteration, a whole group of consequences that can be taken as the measure of the associating efficacy, and in- directlj' of one another. Failure of Memor I/. — Our acquisitions are liable to decay from various causes ; the principal being, of course, insuf- ficiency of the original impression. The others are the absence of occasions of recurrence or rehearsal, and also supplanting associations in the same field ; as when a language is steadily disused, and another, not far removed in kind, gets the benefit of constant practice. All this may occur without prejudice to plasticity in general, or the power of making new acquisitions at an un- diminished rate ; a power that may go on into middle life under favourable circumstances, while decaying inevitably, if slowly, as middle life is passed. There is a double manifestation of the power, constituting a twofold test or aspect of it. The one form is shown in the endeavour to make fresh and lasting acquirements, — as a new manipulation in the arts, a new language, a new science, or a new storage of the historical memory. The other form is more readily accessible to experimental comparison. It is to advert to the ready recovery of what has just been recently in consciousness — those temporary impressions that 484 EETENTIVENESS — LAW OF CONTIGUITY. serve for passing uses and employments and are no further sought to be retained. The point is, whether the failure of this mode of memory is a fair criterion of the rate of failure of the larger and more comprehensive sweep as above described. Presumably it is so, although no regular investi- gation has as yet put it to an adequate test. The illustration in this chapter has had mainly in view our enduring acquisitions. We have generally understood the retainability of an impression to mean the power of recalling it at any future time, however remote. Yet, it is necessary to take account of the tendency of all acquisitions to decay by time ; the rate of decay being dependent on various circumstances, including the failing of the brain itself. It is observed that the impressions that survive, in extreme old age, are those of early years. To keep our acquisitions from decaying, it is requisite that they should be occasionally revived. A language ac- quired in early years may be utterly lost by disuse ; whereas, if kept up till mature age, it will be fixed for life. Sustained practice seems particularly necessary in early education : children's acquisitions are very liable to decompose, if not kept up and confirmed by new additions. No precise laws have ever been ascertained in this department of the human mind. The sj^stem of cramming is a scheme for making tem- porary acquisitions, regardless of the endurance of them. Excitable brains, able to command a very great concentra- tion of force upon a subject, will be proportionably impressed for the time being. By drawing upon the strength of the future, we are able to fix temporarily a great variety of im- pressions, during the exaltation of cerebral power that the excitement gives. The occasion past, the brain must lie idle for a corresponding length of time, while a portion of the excited impressions will gradually die away. This system is unfavourable to permanent acquisitions ; for these, the force of the brain should be carefully husbanded and tempe- rately drawn upon. Every period of undue excitement and ECONOMY OF THE RETENTIVE POWER. 485 feverish susceptibility is fraught with great waste of the plastic energy of the mind on the whole. Is consciousness essential to plasticity'} — It is generally as- sumed that nothing can be laid up in the memory that has not first occupied the consciousness. Indeed, a certain con- scious intensity is regarded as the essential circumstance of any acquisitive growth. This position would never have been challenged but for the fact that sleep and repose some- times enable us to achieve a stroke of intellectual efficiency (such as remembering a lesson) ; there being a total intermis- sion of consciousness meanwhile. The most probable solution of this enigma would seem to be, that all mental efficiency presupposes a certain tone or vigour of the organs at the moment of execution, and that a proper amount of repose may be the means of imparting the re- quired condition. Economy of the plastic power. — This may be said to express the practical conclusion of the entire treatment of the law of contiguity. It is likewise aimed at in the various experi- ments made by different observers, as to the best modes of regulating the direction and stress of attention and the number and timing of repetitions. All this is pre-eminently susceptible of experimental handling ; and is likely to be more and more attended to in the progress of psychological study as well as educational investigation. Hitherto, the experience of the schoolmaster has been the most prolific of valuable suggestions. To this are now added the researches of the various inquirers that have devoted themselves to psycho-physical observations. Both in reference to intellectual acquirements, and in the still more arduous discipline of the Feelings and the Will, important points of economy have been already determined, and have so far justified the time and labour hitherto be- stowed upon the investigation of the mind. CHAPTEK II. AGREEMENT— LAW OF SIMILARITY. Present Actions, Sensations, Thoughts, or Emotions tend to revive their Like among previous Impres- sions, or States. 1 . /CONTIGUITY joins together things that occur together, VJ or that are, by any circumstance, presented to the mind at the same time; as when we associate heat with hght, or a faUing body with a concussion. But, in addition to this hnk of reproductive connexion, we find that one thing will, by virtue of similarity, recall another separated from it in time, — as when a portrait recalls the original. The second fundamental property of Intellect, termed Consciousness of Agreement, or Similarity, is a great power of mental reproduction, or a means of recovering past mental states. It was noticed by Aristotle as one of the links in the succession of our thoughts. As regards our knoivledge, or perception, of things, the con- sciousness of Agreement is second only to Discrimination, or the consciousness of Difference. When we know a thing, we do so by its differences and its agreements. Our full knowledge of red, is our having contrasted it with all other colours, and our having compared it with itself and with its various shades. Our know- ledge of a chair is made up of our experiences of the distinction between it and other articles of furniture, etc., and of the agree- ment between it and other chairs. Both modes are involved in a complete act of cognition, and nothing else (except, of course, the Retentiveness impued in the one and the other) is necessary. Our knowledge of man is the sum of the points of contrast between a man and all other things, and the sum of the points of identity CONTIGUITY AND SIMILARITY MUTUALLY INVOLVED. 487 on comparing men witli one another. Our increase in knowledge is constantly proceeding in both directions : we note new differ- ences, and also new agreements, among om- experiences, object and subject. We do not begin to be conscious till we have the shock of difference ; and we cannot make that analysis of our conscious states, called the recognition of plurality, combination, or complication, till we discover agreements, and refer each part of the impression to its like among our previous impressions. To perceive is, properly, to recognize, or identify. 2. Some preliminary explanation of tiie kind of relation- ship subsisting between the two principles of Contiguity and Similarity, is requisite in order to guard against mistakes, and, especially, to prevent misapprehension as to the separate existence of the two modes of action in the mental frame- work. When the cohesive link between any two contiguous actions or images is confirmed by a new occurrence or repe- tition, obviously the present impression must revive the sum total of the past impressions, or reinstate the whole mental condition left on the occasion immediately preceding. Thus, if I am disciplining myself in the act of drawing a round figure with my hand, any one present effort must recall the state of the muscular and nervous action, or the precise bent acquired at the end of the previous effort ; while that effort had to reinstate the condition at the end of the one preceding, and so on. It is only in this way that repetition can be of any avail in confirming a physical habit, or in forming an intellectual aggregate. But this reinstatement of a former condition by a present act of the same kind, is really and truly a case of the operation of the reproductive principle of similarity, or of like recalling like ; and we here plainly see, that, without such recall, the adhesion of con- tiguous things would be impossible. Hence, it would appear that, all through the exposition of Contiguity, the principle of Similarity has been tacitly assumed : we have everywhere taken for granted, that a present occurrence of any object to the view, recalls the total impression made by all the previous occurrences, and adds its own effect to that total. 488 AGREEMENT — LAW OF SIMILARITY. But, by thus tacitly assuming the power of anything present to reinstate the past impressions of the same thing, we restrict ourselves to those cases where the reinstatement is sure and certain, — in fact, to cases of literal identity of the present and past. Such is the nature of the instances dwelt upon in the previous chapter : in all of them, the new move- ment, or the new image, was supposed precisely identical with the old, and went simply to reinstate and to deepen an impression already made. We must, however, now pass beyond this field of examples, and enter upon a new class where the identity is only partial, and is, on that account, liable to be missed — where the restoration, instead of being sure, is doubtful ; and where, moreover, the reinstatement serves higher purposes than the mere iteration and deepening of the impression already made. In all mental restorations whatsoever, both Contiguity and Similarity are at work : in one class, the question is as to the sufficiency of the con- tiguous bond, the similarity being sure ; in another class, the question is as to the sufficiency of the attractive force of the likeness, the contiguous adhesiveness being believed certain. If I chance to meet with a person I have formerly seen, and endeavour to remember his name, it will depend upon the goodness of a cohesive link whether or not I succeed — there will be no difficulty in my recalling the past impression of his personal appearance through the force of the present impression ; but, having recalled the full total of the past impressions, I may not be able to recover the accompaniment of the name — the contiguity may be at fault, although the similarity works its perfect work of restoring to me my previous conception of the personal aspect. If, on the other hand, I see a man on the street, and if I have formerly seen a portrait of that man, it is a question whether the living reality shall recall the portrait : the doubt hangs not upon the contiguity, or coherence of the parts and surroundings of the picture, if it could be recovered, but upon the chance of its being recovered. Where things are identical, the operation of similarity, in making the present case revive the IMPERFECT IDENTITY THE CHIEF OBSTRUCTIVE. 489 former ones, is so certain that it is not even mentioned ; we talk of the goodness of the cohesive bond between the revived part and its accompaniments, as if contiguity ex- pressed the whole fact of the restoration. To make up for this partiality of view, which was indispensable to a clear exposition, we now embrace, with the like partial and pro- minent consideration, the element that was left in a latent condition ; and allow to sink, into the latent state, the one that has hitherto been made exclusively prominent.* 3. In the perfect identity between a present and a past impression, the past is recovered and fused with the present, instantaneously and surely. So quick and unfaltering is the process that we lose sight of it altogether ; we are scarcely made aware of the existence of a reproductive link of simi- larity in the chain of sequence. Wlien I look at the full moon, I am instantly impressed with the state arising from all my former impressions of her disc added together. So natural and necessary does this restoration seem, that we rarely reflect on the principle implied in it, — namelj^ the power of the new stimulus to set on the nervous currents, with all the energy acquired in the course of many hundred repetitions of the same visual impetus. But, when we pass from perfect to imperfect or partial identity, we are more readily made aware of the existence of this link of attraction between similars, for we find that sometimes the restoration does not take place ; cases occur where we fail to be struck with a similitude — the spark does not pass between the new currents and the old dormant ones. The failure in rein- stating the old condition by virtue of the present stimulus, is thus, in the main, ascribable to imperfect identity. When in some new impression of a thing, the original form is muffled, obscured, distorted, disguised, or in any way altered, it is a chance whether or not we identify it : the amount of * To a mathematical student, this would be made at once intelligible by saying that, in tlie former chapter, the Contiguity is assumed as the variable element, and the Similarity the constant ; in this chapter, Similarity is supposed variable, and Contiguity constant. 490 AGREEMENT — LAW OF SIMILARITY. likeness that remains ^\'ill have a reviving power, or a certain amount of reinstating energy ; but the points of difference or unhkeness will operate to resist the supervention of the old state, and will tend to revive objects like themselves. If I hear a musical air that I have been accustomed to, the new impression revives the old as a matter of course ; but, if the air is pla3'ed w^th complex harmonies and accompaniments, it is possible that the effect of these additions may be to check my recognition of the piece — the unlike circumstances may repel the reinstatement of the old experience more powerfully than the remaining likeness attracts it, and I may find in it no identity whatever with an air previously known, or may even identify it with something altogether different. If my hold of the essential character of the melody is but feeble, and if I am stunned and confounded with the new accompaniments, there is every likelihood that I shall not experience the restoration of my past hearing of the air intended, and, consequently, I shall not identify the performance. 4. The obstructives to the revival of the past through similitude, may be classed under the two heads — Faintness and Diversit3^ There are instances where a new impression is too feeUe to strike into the old-established track of the same impression, and to make it alive again ; as when we are unable to identify the taste of a very weak solution, or to discern an object in twilight dimness. The most numerous and interesting cases come, however, under the other head — Diversity, or mingled likeness and unlikeness ; as when we meet an old acquaintance in a new dress, or in circumstances where we have never seen the same person before. The modes of diversity are countless, and incapable of being classified. We might, indeed, include under diversity the other of the two heads, seeing that faintness implies diversity of degree, if not of any other circumstance ; but I prefer con- sidering the obstruction arising from faintness by itself — after which we shall proceed to the larger field of examples marked by unlikeness in other respects. HOLD OF THE PAST IMPEESSION AX ELEMENT. 491 5. The difficulty or facility in recovering;- a past mental condition, at the suggestion of a present similitude, will plainly depend upon the hold that the past impression has acquired. For one thing, it is much easier to revive a familiar image than an unfamiliar, by the force of a new occurrence. We shall, therefore, have to keep this circum- stance in view, ainong others, in the course of our illustration of the law of Similarit5^ It has to be considered how far natural character — that is, a primitive endowment of the intellect — enters into the power of reviving similars, or of bringing together like things, in spite of the repulsion of unlike accompaniments. There is much to be explained in the preferences shown by different minds, in the objects that they most readily recall to the present view ; which preferences determine varieties of character, such as the scientific and the artistic minds. The explanation of these differences was carried up to a certain point under the Law of Contiguity ; but, if I mistake not, there is still a portion referable to the existence of various modes and degrees of susceptibility to the force of Similarity. From all that I have been able to observe, the two energies of contiguous adhesion, and of attraction of similars, do not rise and fall together in the intellectual constitution ; we may have one feeble and the other strong, in all proportions and degrees of adjustment. I assume for the present that there is such a thing as an energetic power of recognizing similarity in general : but there is no small difficulty in disentangling such a power from the special varieties now to be unfolded ; and the con- sideration of the point may be reserved to the close of the chapter. FEEBLENESS OF IMPRESSION. 6. "We commence with the case of Faintness, or Feeble- ness, in the present, or suggesting impression, considered as an obstacle to the re\-ival of the corresponding previous im- pression. There is, in every instance, a certain degree of 492 AGEEEMENT — LAW OF SIMILARITY. feebleness that will disable the present image from falling into the track left by the same image in its former occurrence. When an extremely faint influence, in the present, revives the old currents, we are at liberty to suppose the restoring action of similarity to be unusually vigorous in that inind, or for that class of impressions. Thus, if, from a very feeble solution of salt in water, such as occurs in many land springs, the impression on the tongue were sufficient to re- vive in one person, and not in another, the past state of mind produced by the tasting of salt, we should naturally remark that the one excelled the other in the attractive force of similarity, so far as concerned that special taste. The superiority, however, admits of being referred to various circumstances. (1) In the first place, mere natural acute- ness of taste, such as is shown in nicety of discrimination, would also show itself in greater readiness to identify a feeble impression. (2) In the next place, there might be a greater previous familiarity with this particular taste, — the consequence of repetition and the other circumstances favouring retentiveness. (3) Distinct from both, although apt to concur with them, is the habit of concentrating the attention upon the sense of taste, owing to some special interest or motive. These are three circumstances having a special or local reference, and not implying greater power of Similarity on the whole ; but we shall find reason for believ- ing, on grounds analogous to those brought forward in support of a general power of retentiveness, that persons may differ as regards Similarity in general. If so, this is (4) a fourth alternative explanation in the case supposed. 7. Such is an example taken at random, to show what is meant by the revival of impressions under the impediment of feebleness. I might go systematically through the Sen- sations of the various senses, to gather illustration of the same fact. (Movements, apart from Sensations, hardly fur- nish cases in point.) In the various sensations of Organic Life, there occur examples of difficult reinstatement, through feebleness of the suggesting sensation. I may experience a IDENTIFYING A FEEBLE SENSATION. 493 certain uneasy sensation, which I cannot describe or identify, because of its being too faintly marked to reproduce the old accustomed impression of the same thing. It may be a derangement of the stomach, or the liver, or the brain, such as I have experienced before, and possess a durable conception of ; but, being too little prominent to strike into the old track, it reminds me of nothing, and I cannot tell what it is. By and by, it increases somewhat, and becomes powerful enough to reinstate some likeness of it in the past ; and I then recognize it. The conditions favourable to the effect are, as already stated, a great acuteness of organic sensibility, previous familiarity, and the habit of attending to organic states ; together with the general power of Similarity. A keen organic sensibility may be noted as a peculiarity of some constitutions, making the individual extremely self-conscious, in the acceptation of being alive to every passing change of organic state ; generating hypochondria and the alternation of fears and hopes regarding one's bodily welfare. The peculiarity will be occasionally found rising to a morbid extreme ; as when the individual never passes an hour without solicitude on the matter of health and mortality. On the other hand, obtuseness of feeling to what is going on within the various bodily parts is a defect fraught with dangerous neglect; while a needless amount of distress, and a needless waste of precaution, may be the result of too much sensibihty, whether this have its origin in the sense or in the intellect. 8. I have already cited an example from Taste. There would be no material difference in the circumstances of a case of Smell. When a very faint odour is recognized or identified, this shows that, notwithstanding the faintness of the impression, the previous sum total of the same smell has been brought back. If two persons be subjected to a particu- lar odour, as in walking through a garden, and if one recognizes it while the other does not, the explanation is to be sought, as before, either in the General Power of Similarity, or in one or more of the three Special and Local 494 AGEEEMENT — LAW OF SIMILAKITY. circumsta.nces— namely, greater natural delicacy or acute- ness of the organ, greater previous familiarity with the odour, and a habit of concentrating attention upon odours in general, or upon this in particular. Could we ascertain that both persons had an equally acute or delicate nose, we should have to account for the difference by the two other local circumstances — greater previous familiarity, and the habit of attention,— or else by the power of Similarity on the whole. If we know that two persons are equal as regards both familiarity with an odour and the habit of attending to it (circumstances tolerably easy to ascertain, and likely to go together), the greater power of identification displayed by one would either prove a special delicacy of the organ, or be referable to Similarity in general. 9. The sense of Touch does not appear to furnish any instructive case of the action of reinstatement made difficult by feebleness of impression; for, we can usually command any degree of contact that we please. We may, however, derive examples in point from Hearing. It often happens that sounds are so faint as to be barely discernible — in which case, we shall observe one person making them out, and another missing them. The difference of acuteness must be referred, as before, to delicacy of ear, to familiarity, to acquired delicacy through the habit of attention, or else to general Similarity. The influence of familiarity, in particular, is well exemplified in sounds. Compare the hearing of our mother tongue with the hearing of a foreign tongue : every one knows how easy it is to catch up an utterance in the one, even when very faintly pronounced, and how we fail in the other under like circumstances. The same contrast is observed between a familiar voice and the voice of a stranger : persons partially deaf identify the speech of those about them, and are unable to understand others speaking at the same pitch. This fact obtains all through the field of associations by similarity : the more thoroughly accustomed the mental system is to an impression, the lighter the touch needed to make it present at any moment. EXALTED ACUTENESS OF SENSE, HOW EXPLICABLE. 495 10. The same line of illustration can be carried out under the Sense of Sight. There is a point of twili.^ht dim- ness when objects begin to be doubtful ; they fail to reinstate the corresponding previous impressions, whereby their identity is made apx3arent. Haziness in the intervening sky, and mere distance, have the same effect. In those circumstances, we find that an object can be identified by one person, and not by others equally well situated for discerning it. Famili- arity, together with professional habits of attention, will, in many cases, explain the difference — as when a sailor identifies a speck on the horizon as a ship of a particular build. Otherwise, the superiority of one person over another in dis- cernment must be ascribed either to sensitiveness of the eye, or to the force of similarity in general. 11. In the case of very exalted acuteness of sense, such as we witness among the Indians, who can discern the tread of horses at a great distance by applying the ear to the ground, and who have also a high degree of long-sightedness, we must refer principally to the two circumstances included in the education of the eye — familiarity and habitual concen- tration. It may be that natural acuteness of sense is heredi- tary in their mode of life ; still, practice is, undoubtedly, a main cause of the remarkable difference in this respect between these savage tribes and the generality of mankind. The education is not simply a frequent repetition of the sen- sations of the tramp of horses or of men on the ear, but the concentration of the brain upon the sense, on those occasions, whereby an intense stretch of attention habitually accom- panies the act of listening. The degree of voluntary atten- tion given to an observation of sense will, at any time, make the sensation more acute : a habit of absorbing attention will generate a permanent acuteness at the expense of attention to other things. A painter will be the more impressed with a landscape that he is deaf to the song of birds, the hmn of insects, or the murmur of the breeze ; the whole soul, passing into one sense, aggrandizes that sense and starves the rest. 496 AGEEEMENT — LAW OF SIMILARITY. 12. The acuteness of the senses in animals may, in like manner, be accounted for. The scent of the dog resolves itself into the identification of an exceedingly faint impres- sion. An effluvium on the nostrils of a pointer, revives the former impression of the smell of a hare ; while, on the human nose, the same effluvium is utterly devoid of effect. Here we must attribute the distinction neither to education nor to the force of the association of similarity, but to the acuteness of the smelling organ. Any given smell will pro- duce a far more intense sensation in a dog than in a man. If we take a scent sufficiently strong to be perceived by both — as when the hare is brought close enough to affect as a smell the human nose — the man is calm in his manifestations, whereas the dog is furious in his excitement. By this, we can see that such is the organization of the smelling organ of the dog that impressions made on it are transmitted to the brain in a highly magnified state ; and, further, it may be, that the brain is specially inflammable to a particular class of sensations of smell, an effect to which nothing corresponding is found in the human constitution. The far-sightedness of birds depends, in part, on the adaptation of their eyes to distant vision. It corresponds with the far-sightedness of persons habituated to remote objects, or to the change that age makes in the lenses of the human eye. We have had occasion to notice the superior development of the adapting muscles of the eye in birds, whereby the organ can go through a greater range of adjust- ment than is in the power of other animals. In the examples under the present head, we have thus brought into view, as circumstances affecting the recall of past impression by a present, a power operating generally, and three local conditions. Probably, in all these instances, the special conditions are of far more importance than the general ; but, whether the natural or the acquired delicacy of a sense usually tells most, we do not pretend to decide. DIVERSITY AS PREVENTING RESUSCITATION. 497 SIMILARITY IN DIVERSITY.— SENSATIONS. 13. We now approach the case that contains the greatest amount of interesting appHcations — the case of similarity disguised by mixture with foreign elements, the Like in the midst of the Unlike. There is often very great difficulty in recognizing an old familiar object, owing to alterations that have been made upon it. Coming back after a lapse of years to a place where we have formerly been, we find houses and streets and fields and persons so altered that we at first fail to identify them ; the differences that have overgrown the per- manent features are, in many cases, such as to destroy their power of reinstating the past impressions. When likeness is thus surrounded with diversity, it is a doubtful point whether the attraction of similars will succeed in reviving the old by means of the new. In these cases of doubtful and difficult reinstatement, there may be observed great differences in the intellectual reach of individuals. Of a number of persons placed in a similar predicament, some will be struck with the likeness — the flash of identity will come over them, and the past will stand side by side with its muffled likeness in the present; others, again, will see no identity — the attraction of the new for the old will, in them, be overborne and quenched by the surrounding diversity. To trace the workings of the attractive force of simi- larity in its struggles with the obstruction of unlike accom- paniments, I count one of the most interesting problems of mental science ; and I trust that, in the course of the illus- tration that will occupy the remainder of the present chapter, my readers will grow to be of the same opinion. Although any natural defect in this link of reproduction is perhaps less capable of being made up by artificial means than in the case of Contiguity, yet we shall see that here too there are circumstances, under our control, that aid in clear- ing the way for the reviving stroke of similarity. 14. Before proceeding to the main subject under the present head, — namely, the Sensations, — I shall advert to the 32 498 AGREEMENT — LAW OF SIMILARITY. one case of Action, or Movement, that furnishes interesting examples of the working of the present law —I mean articu- late action, or Speech. In the numerous and various trains of articulation entering into our education in language, there are many instances of recurring likeness in the midst of unlikeness, leading to the revival of the past by the present. We are constantly recalling past sayings of our own and of other people, and passages of writings that we have read, by hitting on catch-words or identical phrases when our thoughts are running in some quite different channel. The single word ' frenzy,' uttered with emphasis, will recall, in a mind familiar with the passage, ' The poet's eye in a fine frenzy rolling ' ; the principal epithet in such a case being enough to reinstate the entire connected train. Through the suggestion of common words, we can thus leap from one passage to another, by the remotest fetches, in an endless succession of recollections. The character of the mind will determine the prevailing character of the revived sayings : in one mind, they will be poetical and ornate ; in another, the preference will be for prose melody ; in a third, epigram and wit ; m a fourth, sententious wisdom and prudential saws. The say- ings and passages that have been impressed upon us, in the course of our education, will come up through the medium of common phrases ; and the general power of similarity in the mind, modified by the quality of the Articulate sensibility in particular, will determine the abundance of this class of revivals — in other words, the quantity of speech flowing into the utterance of the individual. The force of Contiguity strings together in the mind words that have been uttered together ; the force of Similarity brings forward recollections from different times and circumstances and connexions, and makes a new train out of many old ones. I may have learnt, at one time, a passage from Milton ; at another, an extract from Pope ; on a third occasion, a piece from Campbell. Mere contiguity would enable me, when reminded of the commenc- ing words of any of these passages, to repeat the whole ; but the energetic working of similarity causes me to break CASE OF ARTICULATE SPEECH. 499 into any one or all of them, while speaking on some remote subject. I chance to fall upon two or three words resembling an expression in one of the pieces ; and, notwithstanding the diversity of the context, the old stream of recollection is re-constituted, and the entire passage brought within my command. The attraction of sameness is here manifested as overcoming the repulsion of diversity. I am uttering a connected series of words ; and, among these, one, two, or three have by chance the echo of one of the falls of an old utterance. Instantly, I feel myself plunged in the entire current of the past, and may avail myself of any portion of it to serve my present end in speaking. Neither the unlike- ness of the context, nor the totally foreign nature of the subject-matter, will stifle the reviving action in a mind very much alive to articulate effects. As Contiguous adhesive- ness is measured by the fewness of repetitions necessary to fix a connected speech in the memory, Similarity is measured by the amount of repulsion and disparity that can be over- come, in bringing an old train forward by the force of a new one. Unlikeness of circumstances and situations is no bar to the revival of past expressions, any more than ditference of verbal context and subject-matter. A word casually spoken in some present emergency, will often revive a stream of recollections and incidents long past, where that word chanced to figure as an important turning-point of the history. It is hardly possible to fall into the phrase ' every man to do his duty,' without being put on the track of our recollection of Nelson's last victory. So, the word ' duty ' is liable at any time to bring up the Duke of Wellington. These verbal coincidences are one great link of connexion between us and our past experiences ; they put us ever and anon upon the track of some bygone incident in our history. And the more alive we are to the influence of words, the larger is the share of reviving efficacy that belongs to them. The hold that we have of language is not confined to the articulate organs, but extends over the senses of 500 AGREEMENT — LAW OF SIMILARITY. hearing and sight, and is besides influenced by the emotions ; and I shall, therefore, have to recur to the topic on various occasions. In this illustration, which started from articulate speech, we have anticipated the theme of Language generally, — which must, nevertheless, be resumed in a future page, in consequence of the importance of language in our intel- lectual operations. Besides the general power of Similarity, all the special or local conditions of revival under Feebleness apply to re^'ival under diversity — (1) acuteness of sense, (2) previous famili- arity, (3) acquired delicacy or habits of attention ; and to these, another has now to be added. In the case of a pre- sent object bringing up a past, both resembling it and also differing from it, there is, obviously, a struggle or contest of attracting similarities. In the example now given — language, — a certain passage before the mind may bring up, from the past, another passage resembling in expression, but differing in sense ; or a passage resembling in sense, but differing in expression. This shows that both peculiarities have a power of attraction, each for its own kind, although one prevails, and is thereupon called the stronger attraction. ABC is liable to bring up ADE, the likeness being struck on A; or BFG, on the likeness of B ; or CHI, on the likeness of C. The attraction of B for some combination where it enters, and of C for a combination where it enters, have to be over- come by A, in order to secure the recovery of ADE. Now, the less active B and C are, the more easily will A pre- dominate and effect the recall ; that is, if all the local con- ditions above specified are of a low order as respects B and C, while the same conditions are well developed in A, the chances in favour of A are proportionally great. Hence, the additional circumstance applicable to Similarity in Diver- sity is — a lovj susceptibility, or comparative insensihility , to the points of difference. A speech will recall by preference other speeches resembling in diction, if the individual is more- highly susceptible to language, than to meaning or subject- matter. It is assumed on each occasion, that some one LOW SUSCEPTIBILITY TO POINTS OF DIFFERENCE. 501 feature is the practically important circumstance, with refer- ence to which all other features are treated in the light of obstacles to be got rid of or overpowered. As regards the workings of the mind, however, — that is, the reviving stroke of similars, — every one of the distinctive features asserts itself, and the recall will show which is the most favoured by the circumstances that impart efficiency to the reviving opera- tion. When we come to inquire whether there is such a thing as general similarity, it is this consideration that will be found most relevant in the discussion. 15. To pass to the Sensations. In Organic Life, there are many cases of a sensation repeated with new admixtures, serving to disguise its character, and to prevent its recalling the former instances of the same impressions. It often happens that the same organic state is produced by very different causes. A shock of grief, a glut of pleasure, a fit of overworking, an accidental loss of two or three nights' rest, may all end in the very same kind of headache, stupor, or feeling of discomfort ; but the great difference in the antecedents may prevent our identifpng the occasions. The derangement caused by grief is more likely to recall a previous occasion of a similar grief, than to suggest a time of overdone enjoyment ; the sameness in organic state is, in the case of such a parallel, nullified by the repulsion of opposites in the accompanying circumstances : a state of grief does not permit a time of pleasure to be recalled and dwelt upon ; the loss of a parent at home is not compatible with the remembrance of a long night of gaiety abroad. Hence, we do not identify the supposed state of organic de- pression with all the previous recurrences of the same state ; unless, indeed, a scientific education has made us aware of the sameness of the physical effects resulting from the most dissimilar causes. 16. Under Taste, we have examples of a like nature. A taste may be so disguised by mixture as to be undiscernible ; the presence of the other ingredients operating to resist the reviving power of the one that we desire to identify. In a 502 AGEEEMENT — LAW OF SIMILARITY. solution of Epsom salts, we should not be able to discern a small quantity of sugar ; the saline bitter of the salts over- powering the sugary taste. Again, when malt liquor becomes sour, we are unable to discriminate any longer the alcoholic taste : the acid taste overcomes every other sensation. If, in such a case, the alcohol is still discernible by any one per- son, when others fail to perceive it, we should say that such a one's memory had been specially impressed by alcohol. 17. Hitherto, I have spoken of sensations identified through actual sameness ; the identification being impeded only by other sensations mixed up with them. A case of greater com- plicacy and more importance is furnished by the existence of sensations really different, but having something in common that cannot be seized by itself. Take as an instance the tastes of the various wines. These are all different ; and, if similarity acted only in absolute sameness, port would remind us only of port, claret of claret, madeira of madeira, and so on. But we find that there is so much of a common influence in all wines, that any of them can remind us of a great many others ; we, at the same time, noting points of difference, when they are thus brought into comparison. It is this common influ- ence, with its suggesting power, that has led mankind to constitute what is termed a class, or a genus, ' wine,' com- prehending many widely-scattered individuals. The identi- fication of likeness, in the midst of unlikeness — in other words, of a common property — is the essence of this classi- fying operation. A class is distinct from a catalogue by virtue of a common resemblance, in the midst of diversity. Again, the class, ' wines,' identified through their common organic sensation and taste, is merged in a larger class when spirituous liquors come to be known. There is felt to be an identity between the principal effect of these liquors on the system, and the effect of the various members of the vinous group. The class is now extended ; yet, because of there being some features common to wines that do not attach to spirits, the wines are still retained in a group apart, subor- dinate to the larger group, or as a species coming under the TASTES IDENTIFIED — CLASSIFICATION. 505 other as a genus. The addition of malt hquors to the com- parison extends the identity still farther, and enlarges the class of substances that suggest one another through the common quality of causing intoxication. These malt liquors, being themselves identical in more points than those com- mon to them with wines and distilled spirits, they also make a small species by themselves, contained in the comprehen- sive genus of intoxicating drinks. It was not discovered at first that this influence, common to so many substances derived from such various natural sources (the grape, the sugar-cane, barley, oats, rice, etc.), was owing to one sole ingredient occurring under various combinations. The identification has proceeded solely on their common influence on the human system, and not from a knowledge of the common element, alcohol. Had the grouping proceeded on this perception, the case would have been exactly like the cases already described, where a taste or smell is identified in its mixtures with other tastes or smells. It was, however, a generalization of a common internal feeling or attribute, not of a common external object. Another example akin to the foregoing is furnished by the Pungent Odours. The influence of the various kinds of snuff upon the nose is so well marked, that we readily identif}^ it notwithstanding differences of aroma or flavour. Upon this similarity, we group all the different varieties to- gether, and make a class of bodies, any one of which may be used for any other when the common effect of narcotic pun- gency is desired. The kinds of snuff w^ould doubtless also be identified on the ground of their common origin, the tobacco plant, like wines by the grape. But, looking at the subjective sensation of the snuffs, we find that this assimilates itself to a like sensation produced from other bodies : thus, the odour of smelling salts may, by similarity, recall the odour of snuff's, and the two different substances will hence be brought together in the mind. If we have at any time acquired the impression of hartshorn, this impression also might be re- called in virtue of its resemblance to these others : we should 504 AGEEEMENT — LAW OF SIMILARITY. then have three distinct experiences summoned up from differ- ent times and circmnstances of our past history ; these experi- ences presenting three different substances lying quite remote from one another in nature, but now brought together under the view of the mind, through exerting on it a common influ- ence. If our acquaintance with pungent odours had been still greater, others would be recalled to join the group already formed ; and we should have amassed, from far and near, a multitude of recollections strung upon one common thread of resemblance ; and these recollections would thence- forth be held together as a group in the mind, forming what we term a class, a genus, or a generalization of agreeing objects. In this instance, there is no external element common to all the bodies producing the pungent effect : the classifi- cation is based purely on the common sensation of smell. The smelling salts and hartshorn are identical, inasmuch as both yield ammonia ; but the effluvium of snuff' is not ammonia, although found to bear a resemblance to it in chemical constitution. These various identifications put to the test the force of similarity in different individuals. While seized by some minds, they are wholly missed by others ; and the reason for their being missed usually resolves itself into deficiency in one or more of the five conditions already recounted — natural delicacy of the sense itself, previous familiarity, acquired delicacy, low susceptibility to the points of difference, and general power of Similarity. Moreover, there may never have been any motive or desire to strike out identities in the department. 18. The illustration of Similarity in Touch might be very copious. The intellectual sensations of Touch comprise the feel- ings of Temperature, of Plurality of points, and of Muscu- larity in conjunction with touch proper. Everything handled for the purpose of discerning its tactile properties affects all these sensibilities ; and there may be the greatest variety in TOUCHES IDENTIFIED. 505 their conjunctions, and a corresponding scope for detecting likeness coupled with unlikeness. We identify the soft, warm contact of wool ; the cold, hard smoothness of polished stone ; the roughness of a file — in the midst of diversity of shape, size, and weight. We identify degrees of weight with- out much difficulty, unless distracted by some very acute accompanpng sensibility, as cold or heat. We recognize tactile shape in variety of surface, material, weight, and size. Our discrimination of distinct properties becomes knowledge, only when supplemented by our sense of agreement : a pre- sent high temperature is distinguished from a recent lower, and identified with previous experiences of the same intense degree ; by which means our notion of that quality is com- plete. We are thus in possession of classes of things, based upon each recurring attribute that we are able to identify in the midst of diverse accompaniments. 19. To take next the sense of Hearing. The analysis of sounds has shown us the complexity of the characters attach- ing to any one individual sound, and to what extent identity in some of these may be disguised by differences in others. For example, the pitch of a note may be readily identified when sounded on some voice or instrument familiar to us ; but, on a strange instrument, we are less able to make out the identity. The change of quality in the note, the greater or less emphasis, the different duration of the sound, — as in com- paring a piano note with an organ, — all tend to disguise the pitch, and to render a more delicate or a more cultivated ear necessary for its recognition. If the same note be played feebly on the violin and thundered on the organ, the great disparity of emphasis will confound the obtuse ear, and stifle the feeling of identity. The illustration takes a wider sweep, when we suppose a continuous flow of a sound, — as in a musical performance or a consecutive address. The effects on the ear being more varied, there is greater scope for tracing similarities, and more opportunity for the obstacle arising from diversity. We can usually identify an air that we have once known. 506 AGREEMENT — LAW OF SIMILARITY. on all varieties of instruments, and with or without har- monies. But it will happen to persons, little accomplished in music, to miss a known air when played on a full band, while they could readily identify it on a single instrument. Musicians can also identify the key of a piece, although this point of identity must be enveloped in the widest differences as regards everything else. We are also accustomed to ascribe a common emotion to many compositions ; we classify airs as martial, gay, solemn, sacred, melancholy. In so far as there is any reality in these distinctions, they are made out by the force of similarity, recalling past and scat- tered examples of an effect felt at the present moment. A more substantial agreement is that generally found in the compositions of the same master. The property of articulateness of sound is very apt to be disguised, by strange accompaniments, beyond the reach of identity. Our ear for articulation is formed, in the first in- stance, on the voices around us : we identify with ease a letter or a word as pronounced by those ; in fact, the casual peculiarities of their manner become, as it were, fused with our sense of the articulations themselves. A child born in Yorkshire acquires an ear for the vowels and consonants of the alphabet as sounded in Yorkshire. If we pass into Middlesex, the articulations correspond, without being iden- tical ; and we may or may not identify the old words under the new utterance. The experiment would show whether the ear is good as respects the essential quality of articulate form, just as the trials above alluded to show the degree of delicacy as regards the pitch of a note. Some ears are but faintly susceptible to the distinctiveness of the articulations, or to the essential difference between one vowel and another, and between one consonant and those closely allied to it. If such ears happen to be acutely sensible to the qualities of different voices, and to differences of emphasis, or stress, they will be more strongly acted on by the disagreements than by the agreements. Pronunciation, accent or brogue, cadence and elocution ARTICULATENESS OF SOUND IDENTIFIED IN DIFFERENCE. 507 generally, form a large part of the collective impression of articulate utterance : to which we must add gesticulation and manner as apparent to the eye. Taking all these sources of diversity in connexion with the one main feature of articulate utterance, we may derive an unlimited fund of examples of reinstatement made difficult by unlike accom- paniments. A^oice, pronunciation, accent, cadence, and gesticulation, are inseparable from articulation ; and we become accustomed to the sound of words as beset with a particular mode of each of these effects. Often, indeed, we take up a meaning from manner alone. Accordingly, when we come to listen to strangers, to the people of another province, to foreigners, we experience the difficulty of iden- tifying the articulation in the midst of unusual combinations. The goodness of the ear for articulation proper is submitted to a trying ordeal, as the ear for pitch is tested by the sound of a strange instrument. The trial is greatest of all when we are endeavouring to acquire a foreign language. Here, the one effect of the articulation of vowels and con- sonants needs to make itself felt amid the distraction of a manifold variety of other effects. Nothing proves so decisively the goodness of the articulate sensibility of the ear, as the readiness to follow a foreigner speaking his own language. The power of identifying the essentials of the articulation, in the diversity of all else, is in such circum- stances conspicuously manifested. It will happen, however, that a person is more than usually sensitive to some of the accompaniments that do not concern the conveyance of the meaning: an ear strongly impressed with the accent and cadence, and permitting itself to be much engrossed with the different turns of the emphasis and modulation is, by that circumstance, rendered more obtuse to the articulate character or to the meaning of the words. The thunder of a diverse and unaccustomed cadence drowns the still small voice of expressive utterance. An acute ear for oratory is thus a great obstruction to the acquirement of languages ; so is an eye unduly impressed with gesticulate display. 508 AGREEMENT — LAW OF SIMILARITY. In listening to our own language, spoken in the stjde that we are accustomed to, the sensitiveness to tliose accompani- ments is in our favour, and brings home the meaning all the more powerfully ; but, when they are totally changed in character — as when we listen to a Frenchman — we are just as much put out, in identifying the articulation, as in the other case we were assisted. 20. The ear, as formerly remarked, is the principal matrix for embodying our recollections of language. A speech heard is, in greatest part, remembered as a connected series of auditory impressions. Our recollections of this class are liable to be awakened by similarity, under circumstances of diversity. We can scarcely listen to any address, without being reminded of many past addresses, through occurring phrases, tones, and peculiarities that lead us into some formerly experienced track of impressions on our ear. The greater our susceptibility to the articulate quality that governs distinctness of meaning, the more readily shall we fall upon previous addresses that correspond in phraseology ; if we are more aHve to tone, accent, and cadence, these qualities will preside over the recall of the former occasions when we were in the position of listeners. In this way, we are led to detect similarities of manner and phrase in different speakers ; we hunt out imitation and plagiarism, and institute com- parisons among various styles of address. With regard to the diversities tending to obstruct the reviving impetus of likeness, they may lie in the context of the agreeing phrases, or in the other peculiarities not connected with meaning, or else in the subject-matter and sentiment of the address. As in former cases, we pronounce the attraction of similarity powerful when it breaks through a great discordance, and the discordance great that arrests the reviving stroke of similarity; in fact, we must measure each force by the opposition that it conquers. If a verbal likeness has the effect of interpolating some old recollection, in a subject most discordant with it, we pronounce the conditions aiding verbal similarity to be highly developed, or the regard to the subject feeble, or both. COLOUKS IDENTIFIED, 509 21. Among Sensations of Sight, the occasions for identi- fjring sameness in diversity correspond with the wide range of the sense. We can identify colours, in spite of difference of shade ; obtaining classes of bhies, of reds, of yellows. The existence of such classes implies both sameness and difference ; the class-name being derived from the sameness, or the effect coinmon to all the individuals, ^^^len a colour is intermediate between two principal colours, as between yellow and red, we maj^ fail to class it with either, not being struck with any feeling of identity in the case ; where- upon, we constitute a new colour, as orange. It may also happen that, to one mind, the colour may appear as red, and to another yellow, according to the previous impression that it most readily revives. Next, as to the property of lustre : a varnished substance, a glossy fabric, a polished surface in metal or stone, a film of wet, a clear brook, a covering of glass, — all strike the mind with a common effect of bril- liancy ; and, if the power of similarity is sufficient, each one of these effects may recall the others, so as to muster in the present view a host of things, very different in general appearance, but all agreeing in a particular impression. Looking at a brilliantly polished marble chimney-piece, one man may be reminded only of polished stones of various kinds ; another, breaking through a greater shroud of diver- sity, compares the effect with metallic polish. Speculating yet further on the kind of influence exerted on the mind by such effects, a third person brings up a still more remote subject, varnished surfaces ; from these, he may proceed to glossy silks and polished leather ; and, by a stretch still more remote, he may include in the comparison the effect of a pebbly bottom through a clear running rivulet. But, in order to carry an identity so far as would be implied in this series of objects, it would be necessary that one should have not merely a feeling of the common effect, of lustrous bril- liancy, but also a notion of its depending on a transparent covering over a mass of colour. Such notion, added to the feeling of the effect, might enable one to break through the 510 AGREEMENT — LAW OF SIMILARITY. great difference between a marble chimney-piece and a pool of water. In the combinations of colour with visible Form and Size — the optical with the muscular impressions of sight,— we have an additional scope for tracing likeness amidst diversity. We identify a common colour through all varieties of objects, large, small, round, square, straight, crooked, here and there and everywhere. Thus it is that we have in our mind a class-notion for every colour — a common impression of white, red, or blue, obtained from many diverse objects. Accord- ing to our susceptibility to colour, is the number, the depth, and the permanence of these common effects ; in other words, the distinct shades of colour stored in our recollec- tion. The work begun by Discrimination is completed by Agreement ; both functions concurring to form abiding im- pressions of colours. We identify every various shade in the midst of diversities of material, form, size, and surroundings. The identification and generalization oi forms, in the midst of every possible difference in colour and dimensions, opens up another vein of illustration. We identify a circular out- line in some bodies ; the oval shape in others ; there is an infinity of classes determined by form, including not merely the regular figures of Geometry, but all the recurring shapes in nature and art — egg-shaped, heart-shaped, pear-shaped, vase-shaped, cup-shaped, lanceolate, etc., etc. These com- parisons arise out of identity in the attribute of form, seen through diversity in all other respects. Most of the identi- fications are sufficiently easy to strike any observer ; while instances occasionally arise where only a certain number of minds are struck with the likeness, or experience the re- vival of the old upon the new. Thus, in the descriptions of botany, the shapes of leaf and flower are often represented by comparisons that are far from apparent to an ordinary observer, demanding the familiarized perception of the bota- nist. In anatomical descriptions, there is, not unfrequently, an analogous want of obvious resemblance. The case of mathematical forms and artificial diagrams FORMS IDENTIFIED. 511 is both peculiar and interesting ; but the important strokes of likeness in diversity that occur in science, are rather more complicated than the examples falling properly under our present head. The generalization of the forms themselves — of triangle, square, parallelogram, ellipse, etc. — through differences of subject, is all that we can quote as regards tracing similarity among our sensations of sight. And we may remark here, as on a former occasion, that a strong sensitiveness to the other properties of things, — that is, to their colours, dimensions, material, uses, influences on the feelings, etc., — is an obstruction to the process of identifying the mathematical form. A burning volcano suggests a com- parison, not with the diagrams of the cone in a book of Geometry, but with images of conflagration and explosive energy. Of forms not mathematical, we have the alphabet and the other artificial signs and symbols, used both in business operations and in science. In deciphering bad handwriting, there is scope for identifying sameness in diversity. This is like the case of obscure articulation, discussed under hearing. A strong sense of the points that make the characteristic difference of each letter, and an obtuseness to all the unmeaning flourishes, are the qualities of a good deciphering head. In proportion as a reader is carried away by ornamental shapes, his power of making out the meaning is impaired. This is the exact parallel of what was previously said respecting the effects of over-sensibility to oratorical cadence. The important case of the revival of Language, already brought up, under both articulate action and the sense of hearing, comes in here also, inasmuch as written language appeals to the eye, and is rendered mentally coherent in the shape of impressions of sight. What we have said on the resuscitation of past addresses and sayings, through listen- ing to some one speaking, applies to the reader of books. Forms of language and phrases affecting the eye, recall their similars from the past, and break through a greater or 512 AGREEMENT — LAW OF SIMILARITY. less amount of unlikeness, so as to make present at the same time matters written at different places and occasions. An eye very much arrested and impressed with language is, to that degree, prone to such revivals ; but, according as the written symbols are regarded purely as a medium for con- veying ideas or information, there is a restraint on the tendency to mere symbolical identification. We have here, as formerly, occasion to note the verbal aptitude of the mind, in contrast to the hold taken of the things that are the subject-matter of language, whatever those may happen to be, — whether science, history, poetry, business transactions, or any other. In the verbal mind, as a whole, we can remark the following peculiarities, — 1st, The physical power of articulation well developed : this is shown in the easy acquirement of all the positions of the voice and mouth requisite for speech. 2nd, A good articulate ear, as proved by the test of discrimination. 3rd, An eye for arbitrary visible forms, as in alphabetical or written composition. 4th, General Eetentiveness, or power of contiguous adhesion on the whole. An acquisition so multitudinous cannot prosper unless the general power is well developed. 5th, A certain enjoyment of the exercises of speaking, hearing, and reading, apart from the further ends served by these : this circumstance inspires and sustains the exercise of those lingual functions. To these positive peculiarities, may be added a negative aid, — namely, comparative indifference or insensibility to subject-matter. This is the only thing wanted to enable the Faculty of Language to run riot, as we occasionally find it in our experience of men and women. The artistic forms are a class distinct from both the mathematical and the symbolical. In them, the identity is partly in the literal outline, as traced upon the eye, and partly in the effect of it on the mind, as an object of beauty or grace. The last requisite, being the essential feature, must rule the mind in summoning resemblances from the past. Thus, in the drapery of a statue, we identify some effect that we have formerly been impressed with, and the SCENES OF NATURE IDENTIFIED. 513 stroke of similarity brings up the former objects to the re- collection : on which we find that there is by no means a literal coincidence of lines, and curves, and folds ; but the aesthetic similarity has broken through these and other differences, and has reproduced an instructive arra}^ of artistic parallels. A deep feeling of literal or mathematical forms would be hostile to the aims of the artist. The identification of one Scene of Nature with another may present all degrees of difficulty, according to the pre- dominance of agreements or of difference, and according to the tendency of the mind to be impressed with the one or the other. If the sameness is in form and outline — in the arrangements of mountain, valley, and river, — the reviving stroke of similarity turns on the attraction of the mind for unsjrmmetrical shapes and groupings — one of the features in the catholic susceptibility of the naturalist's mind. If the resemblance to certain other scenes lies in richness, massive- ness of colouring, and strength of contrasts, the chord to be struck is of a different kind ; and such scenes will be revived in a mind alive to these effects, notwithstanding, perhaps, very great differences in the groupings, or formal arrange- ments of the component parts. The same observations are applicable to any other mixed objects of sight or spectacle. When one dress or uniform recalls others ; when the mise en scene of a dramatic repre- sentation suggests parallels from our former experience in those things ; when one face recalls another by similarity ; or even when a picture revives the original,* — in all such cases, the interest, for our present theme, lies in remarking what are the agreeing particulars, and what are the points of dis- cord ; whence we can assign the quality of mind that will experience the recall upon any given attribute. The General power of Similarity would operate alike on * According to Sir Johu Lubbock, savages are found unable to identify a picture with the original. This inability could not hold universally, but would depend upon the circumstances. Even animals, as the dog, occasionally ex- emplify the power. 33 514 AGEEEMENT — LAW OF SIMILAEITY. all kinds of forms, and on all varieties of objects ; reviving with equal readiness, the similar in colour and in shape. But this general power is modified by the acuteness of the sense, as well as by special education, which deepens the hold that we have of some one class of impressions, and makes us all the more ready to fall into that particular set. Hence, it never happens that any individual is equally prone to restore likeness in colour, in geometrical form, in cypher and symbol, and in aesthetic effect. The last class of objects coming under sensations of Sight are visible movements. Among those agreeing in one or more points, classes are made up, and names given indicating the agreement. The flight of projectiles, with considerable disparity, has a common character. In like manner, we have circular movements, elliptic movements, rectilineal move- ments, uniform movements, accelerated movements, rotation on an axle, pendulums, waves, zig-zag movements, waterfalls, explosions, etc. Under all these, we may have great diver- sity in the range and the speed, as well as in the thing moved. The movements of animals afford many other varieties : in quadrupeds, the walk, trot, canter, gallop, shamble ; in birds, numerous characteristic modes of flight ; the darting of the bat, the frog's leap, the serpent's undulation, the crawl of the sluggish snail. By the stroke of Similarity, we bring together in classes a great many instances isolated in their occurrence, and keep hold of them by class-names. We thus generalize the grand varieties of swimming, flying, two-footed locomotion, etc. ; and, within each of these, we have a number of minor classes formed on still closer likenesses. In the flexible and various actions of a human being, we have characteristic types of movement and display. The gait in walking, the action in speaking, the mode of performing any work or operation, the movements on the stage, — are so many objects that excite our notice, and sink into our minds as permanent recollections. The collective movements of multitudes, either in orderly array and disci- plined precision, or in inorganic tumult and confusion, impress VISIBLE MOVEMENTS. 515 themselves upon the view, and spring up as memories in after times. The moving life, over the face of the globe, and in the habitations of men, is more interesting to us than the still life ; it contains more matter of emotion and excitement, and is, consequently, more dwelt upon, both in present reality and in idea. Here, therefore, the force of similarity has a wide arena to perform in. The recurrence of sameness in the midst of greater or less diversity in all these various movements, leads to identification more or less easy. We identify a style of acting on the stage, a dance, a gait, although the circumstances are very different from the examples lying in the memory. If the agreement is not literal, but in a certain general spirit and effect, a strong sense of the literal will be a bar to the recovery of the resembling cases in the past. If we are very sensitive to the stirring effects of movement in general, we are not so likely to identify the special mode. Movements may be divided in a manner parallel to the threefold division of forms ; mathematical or regular move- ments, as rectilinear, circular, elliptical, etc., comprising all the continuous movements of machinery, and all movements that can be numerically calculated or geometrically traced ; symholical movements, or those used for arbitrary signs, such as the gesticulation accompanying directions, commands, instruction, and the like, telegraphic signals, the alphabet of the deaf and dumb, the characteristic gait and movements whereby we discriminate persons and animals ; lastly, ctistlietic movements, or all those that touch the sense of beauty and the interesting emotions. Different minds are variously susceptible to these three kinds, and identify one sort by preference over the others. The aesthetic sense leads to a revival on that point of resemblance, and obstructs the dis- position to classify movements according to their mathe- matical character, or their arbitrary meaning. The most literal and disinterested susceptibility is that manifested to the symbolical and arbitrary, where neither calculable regu- larity nor artistic beauty imparts any attractions. The signals 516 AGREEMENT — LAW OF SIMILARITY. of a telegraph, the motions of a fugleman, the signs used in converse with the deaf, may be ranked with cyphers and alphabetic letters : they give scope for pure intellectual identity and discrimination ; they require to be closely observed and literally compared with those previously known ; the differences are arbitrary, and so are the agree- ments. Their easy recognition further depends on a good adhesiveness for visible forms, and on the absence of emo- tional preferences. 22. There is some interest attaching to the attributes common to Sensations of Different Senses. Impressions, reaching the mind through different avenues of sense, are yet found to have a sameness in the mental feeling or the emotion, this sameness being necessarily accompanied with the difference due to the diverse entries whereby they reach •the brain. For example, many tastes and smells have the character that we call sweet ; but there are also effects on the ear, and on the eye, with so much of the same character, that we apply to them the same epithet. So, the character of 'pungency' is common to sensations of all the senses : under taste, we have it in peppered meats ; in smell, we have sal volatile; in touch, a scalding warmth; in hearing, drum and fife music ; in sight, intense illumination. The amount of sameness in these various sensations is such that one often recalls the others. The identity has long since been struck in such instances ; and is clenched and handed down by the use of a common term, as in the above case of ' sweetness '. The opposite quality, ' bitter,' primarily applied to the sense of taste, has been extended to the emotions, — as when we speak of the bitterness of disappointment or of remorse. The qua- lity that we call ' delicate ' has original reference to Touch ; but, through similarity, it is looked upon as a mode of sen- sation in all the other senses. Comparisons are instituted between sights and sounds ; and the phraseology of the two arts — music and painting — is made interchangeable. A pic- ture is said to have a certain tone ; and a piece of music is, by a less common figure, spoken of as richly coloured. The SENSATIONS OF DIFFERENT SENSES IDENTIFIED. 517 feeling of 'warmth ' is identified as belonging to effects that have no connexion with heat : we hear of warm colom's, and warm affections. Notwithstanding the great disparity there' is between an actual sensation of heat, and a colour or a tender affection, there is a degree of sameness sufficient to break through the discordance in other respects, and to cause the stroke of identification. The designation of one class of sensations as pains, and of another as pleasures, is also the identifying of a common character in the midst of great diversity ; but these qualities are usually so well marked in the mind, being, in fact, the prime movers of our actions, that no amount of diversity can prevent us from recognizing either the one or the other — indeed, a pain not identified as such, that is, not recalling our former painful experiences, would really be no pain. These generalizations among the feelings of our different senses teach us the existence of common mental effects arising out of very different outw^ard causes, and are, in fact, so many discoveries regarding our mental nature. They also serve as illustrations, one of another, in our descriptions of feelings, whether in the common conversation of society, in the higher sphere of poetic delineation, or for the purposes of science, as in the delineations of the Senses attempted to be given in this work. If we are endeavouring to convey to others some state of feeling such as they have not expe- rienced, we bring before their view an identical or parallel state that they have experienced ; and, therefore, we require to possess, through the identifying action of similarity, a store of such hkenesses. This is a frequently occurring attempt in poetr}^ — one of whose objects it is to produce new emotions in the minds of men. The illustration of the feeling roused in the mind of the Duke, in Ticelfth Night, by music is effected by a complicated reference to the other senses : — 0, it came o'er my ear like the sweet south, That breathes upon a bank of violets, Stealing, and giving odour. 518 AGREEMENT — LAW OF SIMILARITY. CONTIGUOUS AGGREGATES.— CONJUNCTIONS. 23. Under Contiguity, we had to notice the aggregation of impressions derived from many different sources, through the circumstance of their proximity, or their striking the mind at the same time. I exempHfied the association of Feehngs of Movement and Sensations with one another, in the notions that external objects create within us, — as in the complex idea of an apple, or a ring. I remarked, further, that, in many objects, the mental impression overflows the immediate sensible impression — as in the whole class of Tools, with which are associated iises ; that is, actions and reactions upon other bodies. In the more profound know- ledge of natural things furnished by experimental science, there are similar aggregates of associated impressions ; as the chemist's idea of sulphur. Now, wherever there is much variety or complicacy in the impressions of outward things, there is room for the detection of likenesses in the midst of diversity. An object acts upon four different senses : the effect on one sense is identical with an effect formerly felt ; but the collateral effects on the three other senses are quite different. I take in my hand a ball of glass : to the touch, it is the same as a ball of polished stone, and might recall the remembrance of such a ball if I had chanced to have been previously cognizant of one ; but, when I look at it, and hear the ring that it makes on being struck, the disparity is notable in both points, and would probably prevent my getting upon the old track of the marble specimen. The most impressive feature of the object being its brilliant effect on the eye, this would have every chance to rule the identifying operation, and prevent my recalling an object entirely destitute of this peculiarity. There might, however, be circumstances to carry my attention off from this effect ; in which case the round smooth touch might start forth to the dignity of striking the recall. In the popular classifications made among familiar objects, the identifying process is seen habitually at work. Looking NATURAL HISTORY CLASSIFICATIONS. 519 out on the landscape, we observe an elevation of the ground, or an ascent from the ordinary level to a high point or peak ; we note this appearance repeated under a great variety of shapes, and in different situations ; we are not prevented by the disparity from recognizing the sameness ; and every new instance, by similarity, reinstates the old. We thus bring together in the mind an array of objects widely scat- tered in nature ; we give them a common name, mountain ; we predicate of each new example the peculiarities that we have found attaching to the previous examples ; we then know, without a trial, that if we were to ascend any one, we should experience a wide prospect, a diminishing tem- perature, and an altered vegetation. In the same way, and with similar consequences, do we classify numerous other groups of natural objects — seas, lakes, rivers, forests, cultivated fields, quadrupeds, birds, fishes, etc. Natural History improves upon the popular classifications : it both searches the globe for materials, and subjects them to careful comparison. The progress of Natural History knowledge has been partly in the number of objects discovered, but partly also in the transition from superficial to deep identities. In the time of Aristotle, animals were classified according to the element they inhabited — one class dwelling on the land, another in the sea, a third in the air ; this point of identity being so prominent and forcible that it arrested every one's attention. Each of these classes could be subdivided by forming minor groups on still closer re- semblances. Thus, we should have, on the Earth, bipeds, quadrupeds, reptiles, etc. ; each of these groups being the assemblage of a number of individuals recalled to the view by special identities. So, in the Air, the insect multitude would be readily marked off from the feathered tribes. It was not difficult to form classes such as these. But more profound inquiry has developed features of identification carry- ing with them a greater amount of agreement, and present- ing points of more value as knowledge, than in those ancient groupings. Birds are now identified, not by the circumstance 520 AGREEMENT — LAW OF SIMILARITY. of their flying in the air, but on the fact of their bringing forth their young in the egg, by their feathered structure, their warm-blooded circulation. Instead of the old group of quadrupeds, or animals walking on all fours, we have the class 7}ia7nmalia (which suckle their young), including both man and quadrupeds, and certain animals of the sea and the air. 24. The operation of Similarity in such classifyings and re-classifyings as the above, has a very high interest ; it sets forth the workings of genius, and the history of science, and of the human mind. The reader has not as yet been pre- pared for fully carrying out this explanation. It is necessary, first, to dwell upon less complicated instances. I might follow the order adopted in developing the Law of Contiguity, and specify instances of the aggregation of impressions of the various senses — the Organic sensibility with Taste, Smell, Touch, Hearing, or Sight ; and it would be easy to lay hold of many cases of identity in diversity among such aggregates. Things affecting the palate alike may yet be very different to the touch and the sight, as m the different varieties of the same alimentary substances, — bread, butter, flesh, etc. Objects that are identical to the eye may yet differ to the taste and the smell, — as water, alcohol, and white vinegar. We make a class founded on the common peculiarity, and give a designation implying that, and no more. If, however, the taste or smell is the point we are bent on studying, we do not pass from vinegar to water, but to other sour bodies, as the common acids. 25. Without pursuing farther the instances of aggregate impressions on a plurality of senses, let us, next, advert to the compounds of Sense and Association. Tools, implements, machinery, and all objects of practical utility, make a class that may stand first in exemplifying this aggregation. A knife, for example, is not simply an object of the senses ; it is this and something more. Along with the sensation that it produces on the touch and the sight, there is an associated impression of its use, or of the cutting operation : and we IDENTIFICATION OF THINGS ON COMMUNITY OF USE. 521 are almost unable to regard it apart from this other circum- stance. The appearance of a knife lying on the table is not the whole knife ; the appearance of it in the hand while we feel its form and dimensions, coupling sight and touch, is not the whole knife : they are at best but signs or suggestive particulars that revive in the mind, by association, the full notion of the object. Here, therefore, we have a complication of sense and intellect, — of impressions made bj^ an actual object, with ideal or associated impressions, arising from previous junctures when we have seen it put to its use. In this association of sensible appearance with use, — the last being only occasionally seen in the reality, and, there- fore, for the most part an idea, or a potentiality, — we have abundant room for the exercise of tracing likeness yoked with unlikeness. We may have similarity in form with diversity of use, and similarity of use with diversity of form. A rope suggests other ropes and cords, if we look to the appearance ; but, looking to the use, it may suggest an iron cable, a wooden prop, an iron girding, a leather band, or bevelled gear. In spite of diversity of appearance, the suggestion turns on what answers a common end. If we are very much attracted by sensible appearances, there will be the more dithculty in recalling things that agree only in the use ; if, on the other hand, we are profoundly sensitive to the one point of practical efficiency as a tool, the peculiarities not essential to this will be little noticed, and we shall be ever ready to revive past objects corresponding in use to some one present, although diverse in all other circumstances. We become oblivious to the difference between a horse, a steam- engine, and a waterfall, when our minds are engrossed with the one circumstance of moving power. The diversity in these had, no doubt, for a long time the effect of keeping back their first identification ; and to obtuse intellects, this identification might have been for ever impossible. A strong concentration of mind upon the single peculiarity of mechan- ical force, and a degree of indifference to the general aspect of the things themselves, must conspire with the intellectual 52'2 AGEEEMENT — LAW OF SIMILAEITY. energy of resuscitation by similars, in order to summon together in the view three structures so different. We can see, by an instance like this, how new adaptations of existing machinery might arise in the mind of a mechanical inventor. When it first occurred to a reflecting mind that moving water had a property identical with human or brute force, — namely, the property of setting other masses in motion, overcoming inertia and resistance, — when the sight of the stream sug- gested, through this point of likeness, the power of the animal, — anew addition was made to the class of prime movers, and, when circumstances permitted, this power could become a substitute for the others. It may seem to the modern under- standmg, familiar with water wheels and drifting rafts, that the similarity here was an extremely obvious one. But if we put ourselves back into an early state of mind, when running water affected the mind by its brilliancy, its roar, and irregular devastation, we may easily suppose that to identify this with animal muscular energy was by no means an obvious thing. Doubtless, when a mind arose less sensible by natural consti- tution to the superficial aspects of things, and having withal a great stretch of identifying intellect, such a comparison would then be possible. We may pursue the same example one stage farther, and come to the discovery of steam power, or the identification of expanding vapour with the previously known sources of mechanical force. To the common eye, for ages, vapour presented itself as clouds in the sky ; or as a hissing noise at the spout of a kettle, with the formation of a foggy curling cloud at a few inches' distance. The forcing up of the lid of a kettle may also have been occa- sionally observed. But how long was it ere any one was struck with the parallelism of this appearance with a blast of wind, a rush of water, or an exertion of animal muscle ? The discordance was too great to be broken through by such a faint and limited amount of likeness. In one mind, how- ever, the identification did take place, and was followed out into its consequences. The likeness had occurred to other minds previously, but not with the same results. Such DISCOVERY OF THE STEAM-ENGINE. 523 minds must have been in some way or other distinguished above the miUions of mankind ; and we are now endeavouring to give some explanation of their superiority. The intel- lectual character of AVatt contained all the elements pre- paratory to a great stroke of similarity in such a case — a high susceptibility, both by nature and by education, to the mechanical properties of bodies ; ample previous knowledge or familiarity ; and indifference to the superficial and sensa- tional effects of things. It is not only possible, however, but exceedingly probable, that many men possessed all these accomplishments : they are of a kind not transcending common abilities. They would, in some degree, attach to a mechani- cal education almost as a matter of course. That the discovery was not sooner made, supposes that something further, and not of common occurrence, was necessary ; and this additional endowment appears to be the identifying power of Similarity in general — the tendency to detect likeness in the midst of disparity and disguise. This supposition accounts for the fact ; and is consistent with the known intellectual character of the inventor of the steam-engine. 26. Let us, next, consider Natural Objects, as seen by the eye of the naturalist, with a view to catalogue and exhaust all their properties and relations. The Mineral, Vegetable, and Animal Kingdoms, as objects of intellectual curiosity and rational explanation, present, in each of their individual specimens, that mixture of the sensible present with the associated absent, already exemplified in the class of tools or machinery. Each mineral, plant, or animal, is a bundle of impressions, of which the whole cannot be made present to the sense at one time ; there being a series of actions upon other individuals to be included in the conception, and these usually held together with the assistance of language. The complication thus presented is a degree beyond the pre- ceding group. In Mineral bodies, we have the concurrence of many attributes in each individual — some sensible, others experimental ; and it is under the estranging influence of much diversity that all the classes have been formed. Thus, 524 AGREEMENT — LAW OF SIMILARITY. to take the Metals. Some of these have a very large extent of sameness— as tin, zinc, silver, and lead ; so, there is a close resemblance between gold and copper, between iron and manganese. But when we come to mercury, a striking point of diversity starts forth ; namely, the liquid form. The in- fluence of this diversity, leading the mind away to water and liquids of every kind, would prevent the suggestion of metals to the mind, but for the strong effect of the two qualities — lustre and weight or specific gravity, — which, acting by them- selves, could suggest by similarity only such substances as silver, lead, tin, etc. This concurrence of two striking points of sameness, overpowers the diverting influence of the liquid state, and brings mercury to the mind's eye, side by side with the metals. But these bodies have been identified with others in the midst of still greater discordance. When Sir Humphrey Davy suggested that metallic substances are locked up in soda, potash, and lime, the identification in his mind proceeded upon resemblances purely intellectual ; that is to say, making no appeal to the senses, but arrived at through indirect signs, and represented to the mind by tech- nical symbols. He found a class of bodies that had a close agreement with one another, and were termed salts ; he saw that some of these consisted of an acid and the oxide of a metal — as sulphate of iron, nitrate of silver ; others consisted of an acid and a substance called an alkali — as sulphate of soda, nitrate of potash. Here, there were a number of bodies brought together in the mind by general agreement ; an oxide of a metal in these bodies suggested by similarity oi function an alkaline substance, both having the property of neutral- izing an acid and forming a salt : it was impossible, there- fore, not to class together in one group all substances having this property ; which was done before the time of Davy, under the name hascs. He, then, by a bold venture, asserted that this common property of neutralizing acids, and making salts, grows out of a still closer identity of character, — namely, a common composition ; in other words, that the alkalies are oxides of inetals too, and that, therefore, all the bases contain a Davy's discovert of metals in the alkalies. 525 metal and oxygen. On the suggestion being put to the proof, it was found to hold good : lustrous metallic substances were actually separated from soda, potash, and the others ; and the identity made good to the sense as well as to the reason. But to trace identities of this nature, a highly intellectual concep- tion is required to intervene ; salts had to be considered, not as appealing to the touch, the taste, and the sight, but as compounded of ingredients represented to the mind by names, figures, and symbols. Had copperas been known only as it appears in a drysalter's store, no such identifications could have grown out of its comparison with other salts. It be- hoved to be known as sulphuric acid combined with oxide of iron, or symbolically as S 0^-|-FeO, in order that an analogy might be seen between it and Glauber's salts, similarly repre- sented as S 0^4- Soda. The scientific identities proceed on scientific conceptions, — that is to say, on artificial ways of ex- pressing, by names, numbers, and symbols, the facts that ex- periment brings to light. The same research led to a stroke of identification that would have been utterly impossible to the common eye, — namely, of hydrogen gas with the metals, — a gas with a solid, — the lightest substance in nature with the heaviest. Hydrogen occurs in connexions that suggest a metal by the force of similarity, — as by its combining with oxygen, and entering into still higher compounds exactly as the metals do. The repugnance between the physical or more sensible properties of hydrogen (gaseous form and lightness) and the properties of the metals, kept back for a time, but did not in the end prevent, au identification on the property of combining chemically in the same manner as these. And in the artificial representations of chemical formulae, the identity is such as to strike the mind very readily ; but this representation was itself consequent on the recognition of similarity of function in the two cases. An acid is now represented chemically in the same form as a salt ; hydrogen standing in the acid for the metal in the salt. Sulphuric acid is /TO, S 0^, the sulphate of iron Fe O, S03. 526 AGREEMENT — LAW OF SIMILARITY. 27. To pass from the mineral world to the Vegetable. Plants may be identified on many different points ; and the same plant falls into different groups of associates according to the feature that predominates in the mind, and determines the stroke of recall. What in the end has turned out the most valuable classification, has often repelled at the outset by obtrusive dissimilarities. In the first Classification of Plants, the Trees of the forest would be grouped together, owing to easy identification through their prominent and imposing points of likeness. The Shrubs would make another class identified by the same superficial likeness. The apparently insignificant and artificial identifications made by LinnEeus would be repellent to a common eye, and could spring only from minute dissection of the structure, bringing out features of identity hidden in the heart of the efflorescence. The Linnaean classification was properly a fetch of identity in the midst of the widest discordance ; and the mental preparation for gaining this triumph of identification, in the midst of difficulties, was a shutting of the eye to the bold features that held all other minds captive, and a devoted study of the minute and concealed structure. Also, the identifying reach of similarity in such a mind must have been of a high order, to produce so great a change in the mode of looking at the whole vegetable world, to break down all the old classi- fications, and compel the adoption of others entirely at variance with them. The vegetable world presents us with another example of pure attraction of Similarity. The analogy of the flower to the whole plant first struck the mind of the poet Goethe, and was considered by botanists a luminous suggestion. He saw, in the arrangement of the leaves round a stem, the analogue of the circular arrangement of the petals of the flower, notwithstanding very great diversity of general appearance. So, in the leaf, Oken identified the plant. The branchings of the veins of the leaf are, in fact, a minia- ture of the entire vegetable, with its parent stem, branches, and ramifications. In the first suggestion of these identities, ANALOGIES IN THE STRUCTUKE OF PLANTS. 527 we have notable cases of the stroke of similarity through a dense medium of diversity. Such identifications (when proved to be genuine and not merely apparent or fanciful), cast new lights over a subject ; simplifying what is complex, and giving a clue to what seemed a labyrinth. 28. Our next examples are from the Animal Kingdom. In the classification of animals, we find the stroke of identity falling first upon one class of attributes, as in the divisions into quadrupeds, birds, and fishes. A minuter examination paves the way for a deeper resemblance : certain animals inhabiting the sea are excluded from the class of fishes — as the whale, seal, and porpoise ; and certain others that fly in the air (the bats for example) are excluded from the class of birds. This new classification, like the reform of Linnaeus in the Vegetable world, proceeded on an investigation of structure, and a disregard of the startling differences that arrest the common eye. It was accomplished by the com- parative anatomists of the last century, and is now fixed for ever in the minds of men, by the language expressing the divisions and subdivisions of the animal kingdom. Numerous interesting comparisons have been discovered between the different parts of animals taken individually. These have been termed homologies. One of the first sugges- tions is attributed to the fertile analogical brain of Oken. Walking one day in the forest, he came upon the bleached skull of a deer. He took it up, and was examining its anatomical arrangement, when there flashed upon his mind an original identity. The skull, he said, was four vertebras ; in fact, the head was merely a continuation of the back bone, but so expanded and distorted as to throw a deep disguise over the fundamental sameness of structure. That disguise was now shot through, by a powerful fetch of similarity, in a mind prepared by previous knowledge for discovering such likenesses. Oken was evidently a man that sat loose to the existing identifications of things. He had, moreover, a large endowment of general Similarity. It appears, further, that he had a strong belief in the simplicity 528 AGREEMENT — LAW OF SIMILARITY. of nature, — that is to say, in the recurrence, or repetition, of the same structure and the same plan of working, in many- various forms and in the most widely separated regions. His convictions on this point went far beyond the reality, as we may see from his writings ; for, of the many hundreds of analogies that he sets forth in his one work, Physio- philosophy, there are probably not twenty that are sound. The intellectual force of similarity in him was under no check or control. He never took any steps to prove the reality of a supposed identification. The identifying stroke of similarity, bringing together, for the first time, things that had previously been looked at in totally diiferent connexions, is the first step in a discovery, but only the first step. It has to be followed up by the labour of comparing minutely all the different things whose resemblance is implied in the iden- tification, and, only after this examination is complete, and the result satisfactory, is the discovery realized. Hence the saying : ' He discovers that proves '. Honour belongs to the first suggestion of a discovery, if that suggestion was the means of setting some one to work to verify it ; but the world must ever look upon this last operation as the crown- ing exploit. The homologies of the skeleton imply a wide range of similarities, sought out through the thickest concealment of diversity. The identity of structure of all animals of the vertebrate class, — mammalia, birds, reptiles, and fishes; the correspondence of the upper arm of the man, the fore leg of the quadruped, the wing of the bird, and the anterior fin of the fish, — implies a very great insight into structure, and a power of setting aside first appearances. The resemblance of the segments of the same skeleton, from the crown of the head to the tip of the tail, constitutes the serial homology ; which is the working out of Oken's fetch on tfiie skull of the deer. The discovery of these homologies represents the struggles of the human intellect with the perplexity of the world. In the explanation of nature, first thoughts are seldom correct. The superficial resemblances bring together HOMOLOGIES OF THE SKELETON. 529 things that have no deep community of structure ; and, hence^ no knowledge is transferred from one to another. The com- parison of a sahnon with a seal can only mislead ; the com- parison of a seal with a whale may improve our knowledge of both. When a superficial likeness in two objects — a sameness in some one prominent feature — is the sign of a deep likeness, or a sameness in many other features, all of great importance, we can apply to the second the whole of the knowledge we have obtained of the first ; that is, by studying one we are master of the two, and thus economize our labour. If I find out that a bat is not a bird, but one of the mammalia, I instantly transfer to it all that I know of the common characters of the mammalia ; but, if I identify a bat with an owl, I gain nothing, for the likeness between the two (their nocturnal habits) is superficial or isolated : it does not imply a number of other likenesses, and the com- parison is, therefore, unprofitable. The progress of real dis- covery consists in seizing these pervading resemblances, and in passing by the others. Often where there is the greatest amount of real sameness, there is the least apparent same- ness ; which only shows that the vulgar eye is satisfied with a very superficial glance at things. PHENOMENA OF SUCCESSION. 29. Under Contiguity, we have classified and illustrated the different kinds of succession prevailing around us. Some are Cyclic or periodic, — as day and night, the seasons, the heavenly appearances generally, the tides, the winds, the revolution of machinery, the routine of life. Others are successions of Evolution, — as in the growth of living beings, and the constructions of human industry. Many are charac- terized by Effect, or the production of some telling sensation, or sudden change, — as a blow, an explosion, a burst of music, a dramatic scene. Apart from these salient manifestations, we have the more comprehensive successions in scientific cause and effect. Lastly, History at large is a grand casemhle of succession, whose aspects are innumerable. 84 530 AGREEMENT — LAW OF SIMILARITY. The identifications traced among these varieties of se- quence, and held together by the use of language, as the common property of civilized men, have vastly enlarged the sum of human knowledge and the compass of human power, besides yielding much refined gratification. They fall under two great divisions, — the Real and the Illustrative ; the one implying an identity in the actual subject or intrinsic quality of the sequence, the other implying a sameness in some mode or aspect of it. Of the first class, are the scientific and prac- tical identities ; the second are those that serve as a medium either of intellectual comprehension, or of artistic adorn- ment. When we term certain atmospheric movements aerial tides, thereby identifying them with the tides of the ocean, the comparison is strict and scientific, for both phenomena are caused by one and the same natural power, — namely, gravitation ; but, when we speak of ' a tide in the affairs of men,' the identity is not real, but merely illustrative, through a certain similarity of phase or aspect : the ebb and flow of human prosperity has no dependence upon gravitation, it grows out of quite another class of natural impulses. 30. The illustrative comparisons, however, are not con- fined to phenomena of succession ; they occur equally among the objects brought in under the previous head, — namely, aggregates, conjunctions, or appearances of still life. On this account, I prefer to treat Illustration as a separate subject ; and, under the present head, Successions, I shall merely cite a few examples of the identification of likenesses considered as real, or believed to be real. I commence with sequences that are periodic or Cyclic. The revolutions of the year are too much alike to present a case of difficult identifica- tion, on which alone any interest hinges. In the rising and setting of the stars, there is one point of similarity that might for a long time escape observation, in consequence of accom- panying dissimilarities, — namely, that, in the same place, the stars all rise constantly at the same angle, the angle being the co-latitude of the place : at latitude 60" the angle is 30°, at latitude 50° it is 40°. Now, there are two disguising SUCCESSIONS OF CYCLE IDENTIFIED. 531 differences in the rising and setting of the various stars ; one relating to the height they reach when at their highest, and the other relating to the time of rising, which last element differs for the same star throughout the year. It takes a steady glance, a ready appreciation of mathematical elements (such as this of the angle of rising), and a considerable reach of the identifying faculty, to seize a community of this kind, in the midst of a dazzling and variegated scene. An absence of poetic feeling would be a favouring condition. In the Vegetable Kingdom, as seen in temperate and cold countries, men soon attain to the generalization of alternating life and death, in the cycle of the year. Notwithstanding the boundless variety and diversity of vegetable nature, this fact, of summer growth and autumnal fading, is too prominent to be disguised by the distinctions between a garden flower and a forest oak. It would, consequently, be one of the earliest generalizations of the human race living out of the tropics. The same remark would apply to the alternation of waking and sleeping, as a fact of animal life in general. The identi- fication of the daily repose of men and animals generally with the hybernation of some species, would be less obvious, but by no means difficult to observant men ; unless, indeed, an artificial obstruction were created by the comparison with death, or with the winter of vegetation, having already got possession of men's minds. The generalization of the planets, or the tracing of a common character, in spite of accompanying dissimilarity, among these wandering bodies, would be interesting to follow, if we could now recover the history of the process. The discovery of the common fact of their circling round the entire heavens, was by no means easy in the case of the inferior planets, Mercury and Venus ; men's minds would in their case be carried away with the more limited circum- stances of their attending on the sun, and their appearing as morning and as evening stars. The successions of Evolution are exemplified chiefly in the growth of living beings. Each plant and animal, in the 532 AGEEEMENT — LAW OF SIMILARITY. course of its existence, presents to our observation a number of successive phases. The great salient facts of birth and death are an easy conquest to the identifying faculty. Special modes of growth can be traced among limited groups, which are thereupon formed into classes; as, in animals, the Ovipar- ous and the Viviparous. The successions of insect life are more complicated. Close observation of individuals is neces- sary to strike out these identities ; so is the absence of vulgar wonderment, poetical illusion, and strong prepossessions. The physiological department called Embryology, includes the knowledge of the earliest evolutions of animals, and is very much dependent upon identifying the modes of growth of creatures considerably different from one another, as the chicken and the infant. The difficulty in such a case is to prove that an apparent identity is real ; so that what is known of the one member of the comparison may, with absolute certainty, be believed of the other. Whereas, in other instances, the discovery is difficult, but the proof easy ; in this, the discovery is easy, and the proof difficult. As to the means employed in ascertaining the genuineness of an identity seen by the intellectual glance of similarity, or the logic of the case, we are not at present concerning ourselves. 31. The Successions making up Human History offer abundant instances of Similarity in Diversity. Nowhere are comparisons, good and bad, more abundantly struck. Plutarch is not the only writer that has set to work expressly to construct historical parallels.* In the situations arising in public affairs, in the problems that have to be solved, in the issues of critical periods, and in the catastrophes that have overwhelmed empires, the intellect of inquiring and ob- serving men finds numerous identities. Sometimes, we com- pare the past with the present ; sometimes, one past epoch with another. And such comparisons are seldom barren efforts of the identifying faculty ; they are usually employed * See the interesting volumes under this title, published by Charles Knight. HISTOEICAL COMPARISONS. 533 for some end of mutual illustration, or in order to infer in the one all the good or bad features belonging to the other. The rise of the British empire is compared, by one class of minds, to the history of the great empires of antiquity ; the object of the comparison being to carry out the analogy to the full length of anticipating for Britain a similar course of decay. The parallelisms that set forth popular government, as conducting to anarchy and ending in military despotism, have been repeated ad nauseam. But such are not the com- parisons that illustrate happily the operation of the principle now under discussion, or that show the results of identifica- tion in enlarging the grasp of the human intellect. For these ends, I should choose rather to point to comparisons made in more limited chains of historic succession. The narrower the field of view contemplated, the more likelihood there is of hitting upon a real and instructive comparison. Take the following, from Grote's Hidonj of Greece. In dis- cussing the changes made in Sparta by the institutions of Lycurgus, the historian calls in question the alleged re- partition of the lands of the state among the citizens. He shows that this is not stated by the earliest autho- rities, and that it appears to have gained credence only after the revolutionary proceedings of Agis and Kleo- menes in the third century, B.C. ; at which time, he thinks, the idea grew up, in consequence of its being strongly sug- gested by the then present desire for a similar re-division. ' It was under the state of public feeling which gave birth to these projects of Agis and Kleomenes at Sparta, that the historic fancy, unknown to Aristotle and his predecessors, first gained ground, of the absolute equality of property as a primitive institution of Lycurgus. How much such a belief would favour the schemes of innovation is too obvious to require notice ; and, without supposing any deliberate impos- ture, we cannot be astonished, that the predispositions of enthusiastic patriots interpreted according to their own partiahties an old unrecorded legislation, from which they were separated by more than five centuries. The Lycurgean 534 AGREEMENT — LAW OF SIMILARITY. discipline tended forcibly to suggest to men's minds the idea of equality among the citizens — that is, the negation of all inequality not founded on some personal attribute — inasmuch as it assimilated the habits, enjoyments, and capacities of the rich to those of the poor ; and the equality thus existing in idea and tendency, which seemed to proclaim the wish of the founder, was strained by the later reformers into a positive institution which he had at first realized, but from which his deo^enerate followers had receded. It was thus that the fancies, longings, and indirect suggestions of the present assumed the character of recollections out of the early, obscure, and extinct historical past. Perhaps the philosopher Sphoerus of Borysthenes (friend and companion of Kleomenes, disciple of Zeno the Stoic, and author of works now lost, both on Lycurgus and Socrates, and on the constitution of Sparta) may have been one of those who gave currency to such an hypothesis. And we shall readily believe that, if advanced, it would find easy and sincere credence, when we recollect how many similar delusions obtained vogue in modern times far more favourable to historical accuracy — how much false colouring has been attached by the political feeling of recent days to matters of ancient history, such as the Saxon Witenagemote, the Great Charter, the rise and growth of the English House of Commons, or even the Poor Law of Elizabeth.' The comparisons contained in this last sen- tence, both suggest the explanation above given of the rise of the belief in question, and impart probability to it when suggested. The same historian has effectively illustrated the general body of Grecian legends, by a comparison with the middle age legends of the Eoman Catholic Church. The range of knowledge possessed by an historical inquirer, on the one hand, and the force of his identifying intellect in that peculiar region, on the other, are the sources of his fer- tility in those comparisons that illuminate the darker specks of the ill-recorded past. Whether those comparisons are strictly applicable and good, depends on a quite different criterion, involving another mental aptitude — the accurate INSTITUTIONAL COMPAEISONS. 535 judgment, or the logical faculty. We find among historians, no less than among Zoological inquirers, the characteristics of the Oken mind — a fulness of analogical suggestion, with an absence of the tests of truth, 32. It is not stepping far out of the class of instances typified in the foregoing paragraph, to advert to Institutional comparisons, whether of different ages or of the same age. The social and political institutions of nations and races have often points of agreement in the midst of great diversity ; and a penetrating mind — in other words, a strong identifying faculty — can bring together the like, out of the enveloping clouds of unlikeness. It is easy, for example, to identify the fact of government as belonging to every tribe of men that act together ; so, it is not difficult for one absolutism to bring to view all the other instances of absolutism that have at different times been impressed on one's mind : and the same with free or responsible governments. By this operation, we gather up various classifications of agreeing institutions, the one throwing light upon the other, and the whole concurring to make one broad luminous effect, which we call the general notion of government ; of absolutism, of constitutionalism, etc. The vast complexity and the seemingly endless variety of human institutions are thus simplified : out of chaos, order arises, as soon as similarity begins to draw together the agreeing elements of the discordant heap. Our great writers on Society, — Aristotle, Vico, Montesquieu, Condorcet, Hume, Millar, James Mill, De Tocqueville, Buckle, Herbert Spencer, — have shown admirable tact in this kind of Comparative History, with all the effects of intellectual illumination and expansion that flow from the bringing together of remote sameness. What the historian does incidentally, the writer on Society does upon system : he searches the whole world for analogies, and finds, if possible, a class for every variety that presents itself. Forms of Government, of Legislation and Justice, Modes of Industry, Distribution of AVealth and Arrangement of Ranks, Domestic Institutions, Religion, Recreative Amusements, etc., are identified and classified so 53() AGREEMENT — LAW OF SIMILARITY. far as they agree, with notification of difference ; and, out of the particulars drawn together in a powerful identifying mind, there crystalhze, one after another, the corresponding generals, and the human reason advances in its endeavours to comprehend this wide subject.* 33. To return to Successions. There remains the com- prehensive department of scientific Cause and Effect (in which many of the foregoing instances are included), or those successions where the consequent depends on its ante- cedent, and is always produced b}- it. Here we remark, that the same link of causation is often repeated in circumstances so widely apart that the sameness is veiled from the percep- tion of the general mass of minds ; indeed, it not seldom happens that, until some preparatory operation has drawn aside the veil, the identity does not disclose itself to the most piercing intellect. Thus, to take the two phenomena — com- bustion and the rusting of iron. It was not possible for any mind to see a common feature in these two effects as they appear to the common eye : the diversity as regards the presence and the absence of heat would of itself be over- powering. It was necessary to go through a long series of investigations, to ascertain the precise import of the two actions apart. Other phenomena had to be interposed having relations to both, in order that effects so unlike should be seen as like. The experiments of Priestley upon the red oxide of mercury were the turning-point in the rapprochement . These experiments showed that, when mer- cury is burned, it becomes heavier, by taking in some sub- stance from the air ; which substance could again be driven off, and the metallic mercury reproduced. The act of com- bustion of the mercury was to all appearance identical with the burning of coal in a fire, while the resulting change on the substance — the conversion of the metal into a red powder — might suggest the process of the rusting of iron ; the chief * ^lillar On Ranks, and the examination of the Hindu Institution in Mill's History of British hulia, furnish striking examples. CAUSE AND EFFECT IDENTIFIED. 537 point of diversity being the time occupied in the two differ- ent operations. Through an intermediate phenomenon hke this, the flash of identity might pass between the two ex- tremes. It is now known that these are instances of the same natural action, — the combination of the sohd material with the gaseous oxygen of the atmosphere. In the great problem of Inductive Science, — namely, to discover the effects of all causes, and the causes of all effects, — there is a variety of intellectual operations gone through : the problem puts on many different aspects. But there is constantly manifested the importance of a powerful reach of the identifying intellect. Some discoveries turn upon this exclusively ; and no extensive series of discoveries can proceed w'ithout it. In truth, the very essence of generalization being the bringing together of remote things through the attraction of sameness, this attractive energy is the right hand of a scientific inquirer. To cite the greatest example that the history of science contains — the discovery of universal gravitation, or the identifying of the fall of heavy bodies on the earth with the attraction between the sun and the planets, — this was a pure stroke of similarity, prepared by previous contemplation of the two facts apart. Newton had for years been studying the celestial motions : by the application of the doctrines of the composition and resolu- tion of forces to the planetary movements, he had found that there were two influences at work in the case of each planet ; that one of these is in the direction of the sun, and the other in the direction of the planet's movement at each instant ; that the effect of the first, acting alone, would be to draw the body to the sun ; and the effect of the second, acting alone, would be to make it fly off at a tangent, or in a straight line through space. By this process of analysis, he had reduced the question to a much simpler state ; he had in fact prepared the phenomenon of planetary motion for comparison with other movements already understood. The analysis was itself a remarkable effort of intellect ; no other man of that time showed the capability of handling the heavenly 538 AGEEEMENT — LAW OF SIMILAEITY. motions with such daring famiharity — of intruding into their spheres the calculations of terrestrial mechanics. The perception of identity could not be long delayed, after such a clearing of the way. Newton had familiarized himself, as the result of this mechanical resolution of the forces at work, with the existence of an attractive force in the sun, which acted on all the bodies of the system ; and he had discovered, by a further effort of calculation, that this force varies inversely as the square of the distance. As yet, the phenomenon of solar attraction stood solitary in his mind ; but it stood out as a remarkably clear and de- finite conception — so definite and clear that, if ever he came to encounter any other phenomenon of the same nature, the two would in all probability flash together in his mind. Such was the preparation on the one side — the shaping of one of the two individual phenomena. Then, as to the other member. He had been acquainted with the falling of bodies from his infancy, like everybody else ; and the impression that it had made on him, for a length of time, was as superficial as it had been in the minds of his brethren of mankind. Like the others he regarded it as a phenomenon of sensible weight, hurts, breakage ; demanding machinery of support and resistance. This was the \dew naturally occurring to him, and, in this encumbered condition, an identity with the pure and grand approach of the distant planets towards the sun, while held at a vast distance from the great luminar}^ was not to be looked for, even in the brain of Newton, whose identifying reach was, undoubtedly, of the first order. He had been, for long, in possession of the prepared idea of solar force, without its ever bringing to his view, for comparison, the familiar fact of a body falling to the earth. It was, obviously, necessary that some preparatory operation should take place upon this notion likewise ; some meditative effort that would partially clear it of the accompaniments of mere smash, breakage, weight, support, etc., and hold it up in its purest form, as a general movement of all free bodies towards the earth's DISCOVERY OF GRAVITATION. 539 surface, or rather in the direction of the earth's centre. There was needed an analytic or disentanghng procedure ; an operation very distasteful and repellent to the common mind, and stamping the scientific character upon any in- tellect at home in it. At what moment Newton laid his analytic grasp upon this ancient experience of our race, we may not now be able precisely to determine : the generally recounted incident of the fall of the apple may have been the culminating point ; but the course of his studies of terrestrial mechanics was the essential element. One cannot help supposing that, when the phenomenon was once taken to task in the way he had already been accustomed to deal with such things, he would very soon eliminate the main fact from all the confusing circumstantials, and see in it an instance of the motion of one body towards another, by virtue of some inherent power in the attracting over the attracted mass. This eliminating generalization would pre- sent the case pure and prepared to his view, as the other had already been by a previous operation ; and then came the flash of identification, and, with it, the sublime discovery that brought heaven down to earth, and made a common force prevail throughout the solar system. Not less to his honour than the discovery itself, was his reserving the announcement, until such time as the proof was rendered complete, by an accurate estimate of the magnitude of the earth, which was a necessary datum in the verifying opera- tion. This great stretch of identification — perhaps the widest leap that the intellect of man has had the opportunity of achieving — not only illustrates the mental attraction of simi- larity, but also presents in relief the preparation of the mind for bringing on the flash. We see the necessity there was for a powerful mathematical faculty, to seize the laws of the composition and resolution of forces, and to apply them to the complicated case of elliptic motion : in this application, Newton already made a step beyond any mathematician of the age. We observe, in the next place, the intense hold 540 AGREEMENT — LAW OF SIMILARITY. that the mathematical aspect of the phenomena took upon him, — how he could set aside or conquer all the other aspects so much more imposing in the popular eye, and which had led to quite different hypotheses of the cause of the celestial movements. This characteristic shines remark- ably throughout the scientific writings of Newton : however fascinating a phenomenon may be, he has his mind always ready to seize it with the mathematical pincers — to regard it in that view alone. His mode of dealing with the subject •of light is an instance no less striking that the one we have been now setting forth. There was in him either an absolute indifference to the popular and poetic aspects of a pheno- menon, or a preference for the scientific aspect strong enough to set all these aside. The example, thus afforded, of un- compromising adherence to the relations of number and measured force, was probably the most influential result of his genius, at a time when physical science was as yet un-emancipated from the trammels of a half-poetic style of theorizing. The purifying or regenerating of the scientific method was far more owing to the example of Newton than to the rhetorical enforcements of Bacon. The human intellect was braced by dwelling in his atmosphere, and his avatar was the foremost circumstance in impressing a superior stamp upon the thought of the eighteenth century. Besides these two peculiarities of the Newtonian mind — mathematical power, and exclusive regard to the mathe- matical and mechanical ; in other words, the strictly scientific aspect of the phenomena to be studied, — I have indicated a third, which, although not radically distinct from these, de- serves separate notice : I mean analytic force, or the tendency to separate the effects that an object has on the senses or the intellect, and to concentrate the regard on one particular at a time. Thus, we have seen that a falling body produces a very complex impression — a gross and multifarious effect ; and this total mass of sensation and feeling is the popular notion of the phenomenon. No accurate knowledge can grow out of such aggregates ; they are the soil of poetry, not THE REASONING PROCESSES. 541 of science. I shall illustrate afterwards the nature of this force, or impulse, that resists the totalizing influence of a complex object, and isolates for study and comparison its individual effects ; I note it here as the volitional, or what may be loosely styled the moral, element of the scientific intellect : it stood forth in singular grandeur in the mind of Newton. REASONING AND SCIENCE IN GENERAL. 34. Not to mention the examples that we have just now parted from, many of the instances of Similarity already adduced in the course of our exposition are strictly of the nature of science. I think it right, notwithstanding, to devote a separate head to the operation of the law in the various scientific processes, with a view to elucidating further both it and them. I shall, therefore, make the illustration fall under the four divisions of Abstraction, Induction, Deduction, and Analogy. Abstraction, Classification, Generalization of Notions or Concepts, General Names, Defi^nitions. — These designations all point substantially to the same operation, — namely, identi- fying a number of different objects on some one common feature, and seizing and marking that feature as a distinct subject of thought ; the identification being a pure effort of Similarity. Thus, we identify the different running streams that have come under our observation, in consequence of the sameness that appears prominent in the midst of much diversity — any new one will recall the previous ones ; and they are assembled together in the mind, not as a miscel- laneous aggregate, but as a class strung on a common thread. In this connexion, they add to our information of each : some we know chiefly at the sources, others at the mouth, some in the mountains, others in the plains ; accordingly, we supply gaps in our knowledge of any one by means of the rest. We may go the length of deriving, out of the fragmentary views, an unbroken whole, an ideal river, that shall include all the features of a complete river ; or we may 5-42 AGREEMENT — LAW OF SIMILAEITY. simply choose one that we know better than the rest, as our representative instance, and, from it, supply blanks in our view of such as we have less perfectly examined. This mutual supply of defects in our knowledge of individuals, is one of the advantages of assembling objects in a class. A second advantage is the substitution of one for another, in any practical end. We know, for example, by some single experience, that a river bank is a convenient site for a town or village ; and so we can choose any one of all the rivers in our knowledge for the same object. Here, then, we have first a classification, assembled by the attraction of similarity ; secondly, a generalization, or general notion, concept, or abstract idea, being some tj'pical river that fairly represents the group, and in which we include only what they all have in common : this typical river may be one of the number, or it may be a composition out of several. Thirdly, we have the application of a general name to the class, the name 'river,' w^hich shall express both the whole, and what each has in common with every other. A fourth operation is all that is necessary to complete the work, — namely, to furnish a definition, or an expression in language, of the agreeing features or common properties* of the class. This exhausts the series of operations connected with the generalization of objects taken as a total or a unity. Of these, the first grows out of pure Similarity ; the others suppose a somewhat more complicated process, to be afterwards described. Take, next, the genus of Bound bodies. As before, these are first mustered b}' the attraction of sameness : their identification has the effects, akeady specified, of mutual en- lightenment and mutual exchangeability. Following up this operation, we seize upon some one instance as a representa- tive or tj^pical instance ; and our idea of this we call the abstract, or general idea. We can here adopt a very refined method : we draw an outline circle, omitting the solid sub- * A river may be defined as a ' natural current of water flowing in an open channel towards the sea,' or to that effect. ABSTRACTION. 543 stance, and presenting only naked form to the eye : this is an abstraction of a higher order than we could gain by choosing a specimen circular object, as a wheel, for it leaves out a greater number of the features wherein circular bodies differ. The mathematical Diagram is thus more of an actual abstrac- tion than the idea of a river or of a mountain derived from a fair average specimen, or than a composite river or mountain. We may advance, however, from the diagram to a Definition by descriptive words ; and we may adopt this as our general conception, and use it in all our operations instead of, or along with, the other. (A circle is defined to be aline every- where equi-distant from a point, which is the centre.) The definition is, in fact, the highest form of the abstract idea, — the form that we constantly fall back upon as the test or standard for trjring any new claim of admission into the class, or for revising the list begun with. I do not here enter into the great controversy of Nominal- ism and Eealism ; having done so in another place (Mental and Moral Science, Appendix A). There is considerable subtlety in stating the precise nature of that mental element called an abstract idea, notion, or concept. The view now prevailing ap- proaches more or less closely to NominaUsm ; denying alike the separate existence of abstractions (Eealism), and the power of mentally conceiving them as such (Conceptualism). An abstract idea, as stated in the text, is one of three things : — (1) The assem- bled group of concrete instances, which may be momentarily repre- sented by a single individual ; (2) a skeleton outline, or diagram, which is still a concrete instance — a circle in Euclid has a definite colour and size, and, therefore, is not any and every circle ; (3) a verbal definition. Sometimes, we may have all the three. The foundation of abstract reasoning must always be an ade- quate host of particulars. To reason about Justice, we must be able to recall a sufficient variety of just actions to bring to view all the characters connoted by justice, and to exclude those that are not connoted. So, with regard to Roundness : we must keep in view several circles differing in material, colour, and size, so as to affirm nothing but what belongs to all circles. 544 AGREEMENT — LAW OF SIMILARITY. The verbal definition provides a mode of seemingly evading this requirement of a plurality of concrete instances. It cannot dispense with the concrete altogether ; but it may make one instance suffice. To understand the definition of matter — namely, something inert, or resisting, — it would be enough to have one example before us, as a cannon ball, provided we un- derstand that all the properties of the ball are to be excluded from our consideration, except its inertness. We may, and do in some subjects, contract the habit of looking at an individual concrete in this exclusive way, — which is the greatest stretch of abstraction within the competence of the mind. But this is the act of the mature intelligence. 35. Induction, Inductive Generalization, Conjoined Pro- perties, Ajffirmations, Propositions, Judgments, Belief, Laivs of Nature. — The contrast between Abstraction and Induc- tion, as here understood, maybe expressed thus : in the one, a single isolated property, or a collection of properties treated as a unity, is identified and generalized ; in the other, a con- junction, union, or concurrence of tv:o distinct properties is identified. We exemplify the first process, when w'e bring all rivers into one class, and define the property common to all ; the second process. Induction, is exemplified when we note the fact that rivers wear away their beds, or the fact that they deposit deltas at their mouths. In the latter case two different things are conjoined : the flow of water over a country to the sea in an open channel, which makes the idea of a river, is associated with the circumstance of depositing or forming land in a particular situation. This conjunction makes an Affirmation, or a Proposition ; the idea of a river by itself, or anything expressed by a noun, is not an affirma- tion. A\Tien we affirm the uniform- co-existence of two dis- tinct facts, we have a Law of Nature, an intellectual posses- sion respecting the world, an extension of our knowledge, a shortening of labour : of the two conjoined things, the presence of one is at any time sufficient to assure us of the presence of the other, without further examination : as INDUCTION. 545 surely as we meet with a river, so surely shall we find the carrying down of mud to be deposited at the mouth, if the two facts be really connected as we suppose. An abstraction or definition gives us a general idea ; it assembles a class of things marked by the presence of this common feature — the class river, the class circle, the class red, the class planet, the class just, — but does not convey a proposition, a law of nature, a truth. In forming these inductive generalizations, w^e need the identifying impetus very much as in abstractive generaliza- tions. The case is distinguished only by being more com- plex : it is properly a stage beyond the other in the order of discovery, although the two are often accomplished by one and the same effort of the sense and the understanding. Still, in order to arrive at the knowledge that rivers form bars and deltas, we require to have observed the peculiarities of rivers, and to have been arrested by their identity on this point. Standing at the mouth of one, and observing the island which parts its stream, we are reminded, by a stroke of reinstating similarity, of the mouth of some other where a similar for- mation occurs, with perhaps many points of diversity of cir- cumstances. These two coming together will bring up others,^ until we have assembled in the mind's eye the whole array that our memory contains. Such is the first stage of an in- ductive discovery ; it is the suggestion of a law of nature, which we are next to verify. The conflux of all the separate examples in one \'iew indicates to the mind the common con- junction, and out of this we make a general affirmation, as in the other process we made a general notion or idea. Now, a general affirmation by means of language makes a, proposition , not a definition ; it needs a verb for its expression, and is a law or a truth, something to be believed and acted on. In like manner, it is by an identification of the separate instances falling under our notice, that we are struck with the conjunction, in an animal, of cloven hoofs with the act of ruminating and with herbaceous food. To take a more abstruse example. We identify the conjunction of transpa- 35 I 546 AGEEEMENT— LAW OF SIMILARITY. rency in bodies with the bending of the rays of hght. These transparent bodies are of very various nature— air, water, glass crystaUine minerals ; but, after a certain length of observation, the identity makes itself felt through them all. By an abstractive process, we gain the general idea of trans- parency ; by looking, not simply at the fact of the luminous transmission, but at the direction of the Hght, we generalize .an induction, a proposition, conjoining two properties instead of isolating one. The operation of induction is thus of the same nature, but more arduous, and implying greater labour, -than the operation of abstraction. The same cast of mmd favours both ; the same obstructions block the way. To make a scientific induction, the mind must have the power of regarding the scientific properties and disregarding the un- scientific aspects : in discovering the refraction of hght, the attention must fasten on the circumstance of mathematical direction, and must not be carried away with vulgar astonish- ment at the distorting effect of hght upon objects seen through water or glass. To take in the more abstruse and dissimilar instances, as the refractive influence of the air, there is needed a preparation similar to that already exemplified m assimilat- ing rust and combustion. Sometimes an induction from a few identified particulars can be fitted in to a previously established formula or gener- ahzation. The preceding instance of the refraction of light furnishes a case in point ; and I quote it as a further example of the identifying operation. The bending of the hght on entering or leaving a surface of glass, water, or other trans- parent material, varies with the mchnation of the ray to the surface : at a right angle, there is no bending ; at all other angles, there is bending, and it is greater as the course is farther from the right angle, being greatest of all when the ray hes over so much as almost to run along the surface. Now, an important identification was here discovered by Snell, —namely, the identity of the rate of refraction at different angles with the trigonometrical relation of the sines of the angles, expressed thus:— The sines of the angles of incidence FITTING (JF INDUCTIONS TO MATHEMATICAL RELATIONS. 547 and refraction bear a constant proportion within the same mediam, or the same kind of material. Here the observed amount of the bending at different angles was fomid to accord with a foregone relation of the mathematical lines connected with the circle. This too may be looked upon as a discovery of identification, demanding in the discoverer not only great reach of Similarity, but antecedent acquire- ments in the geometry of the circle, ready to be started by such a case of parallelism as the above. Inductions falling into numerical and geometrical relations, previously excogi- tated, occur very frequently in the progress of discovery. All Kepler's laws are identifications of this nature : his third law, which connects the distances of the planets from the sun with their periodic times, is a remarkable instance. He had before him two parallel columns of numbers, six in the column, corresponding to the six known planets ; one column contained the distances, another the times of revolution ; and he set himself to ascertain whether the relations of these numbers could come under any one rule of known propor- tiftns. They were not in a simple proportion, direct or in- verse, and they were not as the squares, nor as the cubes ; they turned out at last to be a complication of square and cube. The law of areas is, perhaps, an equally remarkable example of a series of particulars embraced in an all-compre- hending formula, from the existing stores of mathematical knowledge. In all these discoveries of Kepler, we perhaps should admire the aims, the determination and perseverance of his mind, still more than the grasp of his intellect. We have before remarked, that for a man to extricate himself from the prevailing modes of viewing natural appearances, and to become attached to a totally original aspect, is itself a proof of mental superiority, and often the principal turning-point of great discoveries. The identifying faculty in Kepler showed itself less prominently in the particular strokes, than in the mode of taking up the entire problem — the detection of a common character in the motions of the planets and the relations of the numbers and curves. To make that 548 AGEEEMENT — LAW OF SIMILARITY. a pure mathematical problem, that really is one, but has not hitherto been sufficiently regarded as such, is itself a great example of the scientific intellect : it was the glory alike of Kepler and of Newton. A previously equipped mathematical mind, a wide reach of identifying force, and an indifference or superiority to poetical and fanciful aspects, concur in all the authors of discoveries that bind the conjunc- tions of nature in mathematical laws. The great revolution in Chemistry made by the introduction of definite combining numbers, has been even more rapidly prolific of great conse- quences than the discoveries that give Mechanics, Astronomy, and Optics the character of mathematical sciences. The introduction of numerical conceptions into the subtle pheno- mena of Heat, through Black's doctrine of latent heat, ex- hibits a stroke of high intellect not inferior to any of those now adduced. The difficulty of seizing the phenomena of freezing, melting, boiling, and condensing, in a bald, numer- ical estimate, is attested by the lateness of the discovery, if not sufficiently apparent to any one that considers how very different from this is the impression that these effects have on the common mind. The efigrossing sensations of warmth and cold, the providing of fuel and clothing, the prevention of draughts, or the admission of cool air — are the trains of thought usually suggested by the various facts of congelation, liquefaction, etc. : to enter upon those other trains is a con- sequence of special training and endowment, the explanation of which, according to general laws of mind, has been one of the aims of our protracted examination of the human intellect. 36. Deduction, Inference, Ratiocination, Syllogism, Appli- cation or Extension of Inductions. — I have repeatedly urged the value of the identifying process in extending our know- ledge, by transferring all that has been ascertained in some one case to every other case of the same description. This operation is described under the above titles. It is an Inference, a Deduction, a step of Reasoning, the extension of an affirmation from the known to the unknown. The DEDUCTION. 549 discovery of a full identity between the new cases and the old, is a justification of this transference of properties. Having observed, in innumerable cases, that human beings go through a course of birth, maturity, decay, and death, we transfer their fate to those now alive, and we declare before- hand that each and all of these will go through the same course. This is to make an inference, to reason, to apply our knowledge to new cases, to know the future from the past, the absent from the present. So, when we land on the banks of a strange river, we instantly act on the assumption that this river has its origin in high lands, its destination in the sea, and, at its mouth, a deposit of mud of larger or smaller dimensions. The little that we see of the river, by walking a few miles along its bank, is enough to identify it with the rivers already known to us, or with our general notion, or abstract idea, or definition of a river ; and, on this identity, we forthwith transfer all our experience connected with rivers in general, and all then- conjoined phenomena, to the newly occurring individual case. When our knowledge comes thus to transcend our actual experience, we are properly said to draw an inference. This process of influence, or extension of properties^ therefore, evidently comes of the identifying faculty, by which the new cases and the old are brought face to face before us. If the question be, — Given a certain number of particulars, where a natural law is exemplified, to discover other particulars whereto we may extend or apply the law, and so reveal new characters in those particulars, — these new cases must be summoned to the view by a stroke of simi- larity. Thus, Newton observed, in various instances, that, when a transparent body is largely made up of combustible matter, as an oil or a resin, it bends light to an unusual degree ; in other words, he made an induction of particulars where combustibility of substance and excessive bending of light were conjoined properties. He next bethought himself of any other substances, besides those in his immediate view, that possessed one of these properties, and his recollection of 550 AGREEMENT — LAW OF SIMILARITY. the refracting power of the diamond responded to his call by a stroke of similarity : he, thereupon, extended to the diamond the other property, — namely, combustibility of material ; or inferred, what no one had ever experienced, that the diamond is a combustible substance, a singular exception to the class of precious stones. This obtrusion of observed coincidences upon all parallel cases, the active search for new particulars to have the observed properties thrust upon them, is one of the ways of extending the domain of knowledge. The inquirer has got in his hand a clue, and makes a business of following it out wherever he can find an opening ; he has made his induction, and lies in wait for opportunities of pushing it out into deductions. In this endeavour, he relies on his identifying faculty ; which, if pow^erful, makes him, as it were, keen-scented for every- thing in the memory of the past that bears a resemblance to his case : the recollections that, in an obtuse mind, would lie unawakened by the magnetism of similarity, in a mind of a different stamp, start out one by one for examination and choice ; and in this lies the harvest-home of the man of intellect. The converse may next be put. Given an obscure phe- nomenon, to illuminate it by bringing forward parallels or identities among phenomena that are clear and intelligible ; it being supposed that such have actually occurred at some time or other, although in connexions altogether remote from the present difficulty, so that only the force of Simi- larity can bring them up. The position of the inquirer is altered, but the intellectual operation is the same : to sum- mon the clear to illuminate the dark, or to summon the dark to be illuminated by the clear, must alike proceed on a felt identity; which identity is both the mental link of attraction, and the circumstance that justifies the transference of infor- mation from the one to the other. We have already had instances in point ; but, instead of recurring to these, I will cite the great identity made out by Franklin between the thunder and lightning of the sky, and electricity, as shown DEDUCTIVE EXPLANATION. 551 on the common electrical machine. Next to the discovery of gravitation, this is perhaps the most remarkable fetch of remote identification in the history of science. The pheno- menon of the thmidery discharge was an exceedingly obscure and mysterious action. The natural obscurity of the case was further increased by the emotions habitually inspired in men's minds; for nothing is more difficult, than to identify, on a mere intellectual similarity, what excites deep emotions, (especially fear), with what excites no emotion at all. Only a cool intellectual nature, like Franklin's, was a match for such a case. He could face the evolution of a thunder- storm, and watch it with all the calmness that he w^ould have shown in an ordinary philosophical experiment, de- hberately bethinking himself the while of any parallel phenomenon wherewith he could identify and illustrate it. Had he lived a hundred years earlier, his attempt would have been in vain ; for, of all the scientific facts that could have crossed his view in the middle of the seventeenth century, there was no one that bore upon the case in hand, either obvious or remote. In the eighteenth century, his- position was different : the electrical machine was a familiar instrument, and an intelligible account of its phenomena had been rendered ; and these phenomena had been expressly studied by Franklin, and were vividly impressed on his mind. To his cool eye gazing on the storm, the forked lightning identified itself (in the midst of a diversity that few minds could have broken through) with the spark of an electrical discharge. This was, indeed, the only feature of resemblance, unless a favourable accident had revealed some other coincidence, such as the existence of an electrical charge in the clouds before a storm ; and the identification must be ranked among the grandest fetches of Similarity. The identity once struck was duly verified, and proved to be a real and not a superficial or apparent sameness ; being, in fact, the same natural agent showing itself in widely different situations. Then came all the deductive applications : the circumstances known to accompany and precede the dis- 552 AGREEMENT— LAW OF SIMILARITY. charge of a Leydeii jar could be transferred to the electrical storm ; the charging of the clouds with one electricity and the earth with an opposite, the increase of electrical tension to the pitch that an intervening insulator could no longer restrain, the shock of discharge, — were seen, through the medium of the familiar parallel, to be the routine of the lightning and thunder of the sky. Every new fact, ascer- tained upon the machine, could thenceforth be extended to the electricity of the atmosphere ; what was not discover- able by examining this directly, could be known through the other, as "a deductive inference. The subject of electricity could furnish many other ex- amples of scientific identification on a great scale. 87. Reasoning by Analog)/. The three foregoing sections include three out of the four leading processes, or cardinal operations of discovery. (The process of Observation, in one sense the foundation of the whole, does not depend directly upon the faculty we are now discussing.) Every great step in science, exclusive of original observations and experiments, is either an Abstraction, an Induction, or a Deduction. But resort is occasionally had to Analogy, instead of Identity, as a basis of deduction or inference ; and, for our purpose of illustrating similarity, the striking out of analogies is in point. As an example of analogical reasoning or inference, I may take the comparison of human society to a family, with the transfer of the duties and powers of the head of the family to the Sovereign of the state. This transfer is an in- ference or deduction, and is often tendered as a reason for the tutelary and despotical character of the Sovereign. The two cases are not identical ; they possess an analogy, and a good reasoner remarks how far the analogy holds, and con- fines his inferences within those limits. In like manner, human society has suggested the analogy of herds and hives, — a comparison much insisted on by Aristotle. A mind well stored with numerous conceptions, the fruit of various studies, and having at the same time a good reach of the identifying faculty, can strike out analogies when identities fail ; and, by REASONING BY ANALOGY. 553 their means, a certain amount of insight is sometimes obtain- able. We have had occasion to advert to one remarkable scientific analogy, — namely, that between nerve-force and common electricity ; from which we have not hesitated to draw inferences, in order to support a certain view of the manner of working of the nervous system. Sometimes, a further investigation will convert an analogy into an identity, as was the case with gravitation, — if it be true that Hooke came so near as to quote terrestrial gravity as an illustration of solar attraction ; and as may be the case with electricity and nerve-force. But analogies, in another sense of the word, are similarities of relation in diversity of subject, — as in the case of society already quoted, where the analogical char- acter is the permanent fact. The circumstance of evolution, attaching to the vegetable and animal kingdoms — the suc- cessive stages of birth, growth, and decay — is but an analogy as between a plant and an animal ; to a still greater degree is this the case, when we are comparing the mental develop- ment of a human being with the growth of a tree, not to speak of the much more remote comparison between the growth of humanity, as a whole, and the progress of an in- dividual animal, or plant. This last analogy is, indeed, too faint to be of any value, and is misleading if deductions are made from it. The logical caution that must accompany discoveries of supposed identity, is still more called for in the slippery regions of analogy. 38. The exemplification now given of Similarity operating in Science, is a nearly complete account of the nature of the intellectual faculty called Eeasoning. Some philosophers, as Reid and Stewart, have separated the mental processes concerned in Science into two — Abstraction and Beason. The one is the first of the three operations described above ; the other. Reason, would be interpreted as covering Induc- tion and Deduction. Sir W. Hamilton includes the whole under one head, — variously named by him the Elaborative or Discursive Faculty, Comparison, the Faculty of Relations, and also Thought, in a certain narrow sense, as when Logic 554 AGREEMENT — LAW OF SIMILARITY. is defined 'the science of the laws of Thought'. In the detailed exposition, he divides the operations of the Faculty into two parts, corresponding to the division into Abstraction and Reason {Lectures on Metaphysics, ii. 277). This seems the best view to take of the scientific faculty. As regards the mental forces concerned — the chief of these being Similarity, — there is no essential difference between Abstraction, on the one hand, and Induction, or Deduction, on the other ; although the subjects and products are so far different, that it is convenient to illustrate them separately. In remarking above that Similarity does not explain the whole of the scientific faculty, I mean that Abstraction, Induction, and Deduction, frequently involve something besides the bringing together of resembling particulars or facts ; what that something is, will be seen in the chapter on the Constructive operations of the Intellect. BUSINESS AND PRACTICE. 39. In Business or Industry, in the power of intelligence applied to the affairs of life, in Practical Genius, we find exemplified the discovery of deep identities amid superficial differences. In the inventions of practical art, no less than in the discoveries of science, the identifying facult}^ is called into play. The labours of Watt, in the steam-engine, might with great propriety be farther cited, to correspond with the greatest strokes of scientific identification. Perhaps his ' governor balls ' is the most illustrative example for our present purpose. Here, he had to devise a method of opening and closing a valve, in connexion with the diminu- tion or increase of the speed of a very rapid wheel move- ment ; and no device in the range of existing machinery would answer this object. He had, therefore, to venture out into the region of mechanical possibility, to seek among mechanical laws in general, or among very remote natural phenomena, for a parallel situation ; and he found the only case that has yet been hit upon, — namely, the action of - EXTENSION OF MECHANICAL DEVICES. 557 a centrifugal force where two revolving bodies partvould come together, according as the rate of revolution is ace the rated or retarded. I am not aware of any stroke of remdon identification, in the history of mechanical invention, sui passing this in intellectual reach : if such a power of bringing together the like out of the unlike were of usual occurrence, the progress of discovery would be incalculably more rapid. Another instance of Watt's power of identi- fying a practical situation with some other case where the requisite construction is given, was the suggestion of a lobster-jointed pipe, for conveying water across the bottom of the river Clyde. The inventive genius is ever ready with a suggestion derived from some already existing device, disguised from the sight of other men, either in the arrange- ments of nature or in the constructions of art. Identifying power, although not expressing everything that constitutes an inventor, will be found a prominent feature in the character. As in the other departments, so here also, the identifying faculty must operate in a suitable region of previous acqui- sitions and experience. In the able administration of private business and public affairs, we shall often be able to detect the same force at work, although not always designated invention or genius. Either in meeting new cases, or in bringing superior methods to bear upon old, there is a march of mind, an advance over routine, which marks the able administrator ; and here, too, the link of power consists in a more than ordinary force of identification. AVhen a present emergency is exactly like a previous one, it recalls that one without difticulty, and is treated as that was treated; when it corresponds exactly to no one before, a subtler mind is wanted — some parallel must be sought for, away from the routine of cases. Into quite remote regions of affairs, the man of penetration is carried, and finds something in point where perhaps no parallel was ever drawn before. The application of the Syllogism to Law pleadings was a great legal improvement, which has persisted while scholastic forms have gone gener- ^"^^ AGEEEMENT — LAW OF SIMILARITY. ^^ *^?iito decay. No routine lawyer was capable of such an ovation. If, for illustration's sake, we suppose it to have ^^^^sn the work of one person, it implies a mind that came to ^Iie study of law previously prepared with the scholastic training, and detecting in the pleadings before the courts a real identity in form with the discussions of the schools, although hitherto conducted with no such method or preci- sion. The transference of the syllogism to the legal reason- ings would be the consequence of this feeling of identity ; and hence would arise that capital requirement of making parties plead separately to the law, and to the facts of the case, instead of huddling up both in one argument as is usually done in the controversies of every-day life.* It is usual for practical devices to be first employed in obvious cases, and thence transferred to other cases of a like nature, but of more complexity. Thus, in the great institu- tion of the Division of Labour, now so widely ramified over all departments of industry, there could be traced a progressive application : we should find it commencing in manual industry, and in the separation of the primitive classes of agriculturist, artizan, trader, soldier, and priest ; and thence, in later times especially, extended into the warehouse and the manufactory, into public business, and into scientific research. In every new step, there would arise, in the mind of some one person or other, a feeling of similarity between the exigencies of a work in hand and the cases where the method of divided laboar was already in operation ; and this identification would suggest the further extension of the practice. I do not at present speak of the faculty required for overcoming the difficulties of detail in all new applica- tions of old machinery (although here too it would be found, * The system of separating the law and the facts, in legal pleadings, did not arise as I suppose in the text, and as might have been the origin, from an application of the scholastic logic, but from our Saxon institution of trial by jury, where the facts were decided on by the jurors, and the law declared by the judge. Nevertheless, the illustration answers our purpose, even in its hypothetical character. EXTENSION OF ADMINISTEATIVE ARTS. 557 that a fertile power of recalling identities in diversity would be the principal instrument of success, in so far as the intellect was concerned), but confine myself to the suggestion of a device taken from some parallel case. In the progress of free governments, there has been gradually diffused, from the lower to the higher and more difticiilt posts, the principle of responsibility as a check upon the abuse of power. This practice grew up by a progress of extension, until, m the constitutional governments of Europe and America, it came to include every executive officer in all departments of State. The experience of the practice, with the more humble functionaries, suggested its application to the exactly parallel case of superior officers ; and, after much struggle, not of an intellectual kind, it got to be introduced into modern free communities, as it had been in the constitution of ancient Athens. It was discovered very early in the practice of societies, that the only method of attaining the truth in legal disputes was to hear both sides alike. This maxim, by successive assimilation, has found its way into every department where human interest and opinions come into conflict. The principle of not interfering with individual tastes and sentiments, except in so far as these affect the legitimate happiness of others, is recognized in certain cases, and has had a tendency to expand itself by assimilation into cases encumbered with obstructive circumstances. Hence, has sprung up what amount of toleration in belief and in conduct we now possess ; although the difficulty in proceeding far with this extension, shows how effectually the love of domi- nation and of uniformity may stifle the assimilating action of the intellect. In the suggestions of a practical mind, the identification should always turn upon the relevant circumstances, and overcome other attractions of sameness on irrelevant points. To attain to tiiis characteristic is the end of a practical education, which makes the person familiar with the aspects that serve the ends contemplated. Thus, a lawyer, in recover- 558 AGEEEMENT — LAW OF SIMILARITY. ing, from his past experience, the precedents and analogies suitable to a case in hand, is impelled by the force of simi- larity working in his mind ; but, of the many peculiarities of the case, he excludes the assimilating action of all except the one that would govern its decision before a judge. His education must serve him in making this discrimination ; and if (as may happen) he is by natural temperament keenly alive to this one feature constituting legal relevancy, and indifferent to all other points of interest in the case, he is a born lawyer, — ^just as Newton, with his natural avidity for mathematical relations and indifference to sensuous and poetic effects, was a born natural philosopher ; or Milton, by the opposite character, was a born poet. That nature should chance to turn out a legal mind is not singular or surprising, for it is only a variety of the scientific or logical intellect, using verbal forms as the instrument, and implying an obtuseness to all the more popular and interesting features of human life. To secure a rigorous uniformity in dealing with disputes, scientific definitions must be made, and equally applied to the most diversified cases. 40. The last form of practical ability that I shall here advert to is persuasion. This implies that some course of conduct shall be so described, or expressed, as to coincide, or be identified, with the active impulses of the individuals addressed, and thereby command their adoption of it by the force of their own natural dispositions. A leader of banditti has to deal with a class of persons whose ruling impulse is plunder ; and it becomes his business to show them that any scheme proposed by him will lead to this end. A people with an intense overpowering patriotism, as the old Eomans, can be acted on by proving that the interests of country are at stake. The fertile oratorical mind is one that can identify a case in hand with a great number of the strongest beliefs of an audience ; and, more especially, with those that seem, at first sight, to have no connexion with the point to be carried. The discovery of identity in diversity is never more called for, than in the attempts to move men to adopt some un- THE MEANS OF PERSUASION. 559 wonted course of proceeding. When a new reform is intro- duced in the state, it is usually thought necessary (at least in England) to reconcile and identify it in many ways with the ancient venerated constitution, or with prevailing maxims and modes of feeling, with which it might seem at variance. To be a persuasive speaker, it is necessary to have vividly present to the view all the leading impulses and convictions of the persons addressed, and to be ready to catch at every point of identity between these and the propositions or projects suggested for their adoption. The first-named quali- lication grows out of the experience and study of character ; the other is the natural force of Similarity, which has often been exemplified in its highest range in oratorical minds. In the speeches of Burke, we see it working with remarkable vigour. Perhaps the most striking instance of this fertility of identification for persuasive ends is exhibited in Milton's Defence of Unlicensed Printing. Of the class of preachers, Barrow is especially copious in his command of topics of persuasion and inducement towards the performance of re- ligious and moral duties : in him, no less than in Milton, we have everywhere the tokens of an identifying mind of the highest order. ILLUSTRATIVE COMPARISONS AND LITERARY ART. 41. When two remote phenomena are brought into com- parison by a flash of similarity, they may turn out to be repetitions of the same natural agent working in different situations, — as in the great examples of lightning and the electrical discharge, the fall of a stone and the moon's gravi- tation to the earth. The comparison in these cases is real, literal, or substantial. It is illustrative and instructive in no ordinary degree ; but it is more than an illustration, — it is a scientific discovery : the two things identified are so thoroughly of a piece, that we can go all lengths in reason- ing from the one to the other. There is, however, also an extensive and useful class of comparisons where real identity 560 AGREEMENT— LAW OF SIMILARITY. is wanting ; the likeness being yet sufficient to justify us in interpreting the more obscure and remote by the more intel- hgible and famiHar of the two ; as when, in speaking of the action of supply and demand in commerce, we say that these are constantly finding their level. Here, the subjects compared are quite different in their nature ; the one belong- ing to the province of mind, and somewhat obscure, while the other is a physical phenomenon of a very palpable and intelligible sort. Illustration after this fashion is one of our devices for representing to the mind what is either naturally obscure, or accidentally concealed from the view. If we can only see enough of the object to suggest an appropriate comparison, we make use of that to supply the rest. The force of similarity has extensive scope in this department of discovery. Illustration is particularly wanted to convey scientific notions and abstractions. These are often so artificial and abstruse, that an ordinary mind has great difficulty in seizing them. Such abstruse physical phenomena as the molecular constitution of matter, polarity, chemical affinity, the ethereal undulations supposed to constitute light and heat, the growth of cells in living bodies, — demand to be expressed by com- parisons drawn from theseen and palpable. Human actions, feelings, and thoughts, are often so concealed in their work- ings, that they cannot be represented without the assistance of material objects used as comparisons : hence, the great abundance of the resemblances struck between matter and mind. AVe speak of a clear head, a warm heart, a torrent of passion, a poet's fire. The comparisons brought to bear upon the complexities of social life are likewise very numerous ; in fact, there are many social phenomena that we never con- ceive otherwise than in some species of material analogy. If we take, for example, the different ideas connected with social order and disorder, we find the language almost wholly derived from other things ; scarcely a phrase is literal, all is metaphorical. ' The vessel of the state weathers the storm, or is in danger of wreck '; anarchy is described as ' chaos,' ' con- COMPAEISONS FOR ILLUSTRATION. 561 fusion '; the government is said to be ' shaken,' or ' stable,* or ' tottering '; law is ' erected,' ' overthrown'. We speak of the ' life' and ' growth" of society ; when we conceive of pro- gress, it is generally in a figure, — we call it ' movement,' 'development,' 'enlightenment,' and so forth. Of all existing compositions, the writings of Lord Bacon are perhaps the richest in illustrative comparisons of the kind now under discussion ; not being scientific identities, and yet serving in an eminent degree the purpose of assisting the popular intellect to embrace difficult notions. In virtue of this surprising power. Bacon's doctrines become clothed in ' winged words'. According to him, science is the ' interpre- tation' of nature — -a comparison that transfixes the mind with the idea of observing, recording, and explaining the facts of the world. Final causes, he says, are ' vestal virgins ' — they bear no fruit. But for the simile, it is doubtful if this notion would have stuck in men's minds, and been the subject of keen controversy, in the way that we have seen. His classi- fication of ' Instances,' or forms of experiment and proof, is wholl}' embedded in strong metaphors : the 'experimentum crucis,' the finger-post between two ways, has been adopted in our logical nomenclature. Fallacies, or modes of mental bias, are with him ' idols ' {eidola, false appearances) — of the ' tribe,' of the ' den,' of the ' market-place,' of the ' theatre '. A remarkably powerful identifying intellect, embrac- ing the concrete facts of nature and human life, and the history and literature of the past, is implied in this mode of genius, of which Bacon is the highest instance. The sus- ceptibility to certain classes of objects and impressions determines the particular element that the resuscitating faculty must work in ; and, in some men, this susceptibility is to the concrete in general, rather than to the select and narrow class of the artistic or poetic concrete. Thus, although Bacon's imagery sometimes rises to poetry, this is not its usual character : his was not a poetic sense of nature, but a broad general susceptibility, partaking more of the natural historian than of the poet ; by which all the objects coming 36 562 AGEEEMENT — LAW OF SIMILARITY. before his view, or presented to his imagination, took a deep hold, and, by the help of his intense attraction of Similarity, were recalled on the slightest resemblance. Many great writers in English literature have had this strong suscepti- bility to the sensible world at large, without a special poetic sense ; while some have had the poetic feeling superadded : these last are our greatest poets, Chaucer, Milton, Shake- speare. 42. This leads me to notice the second class of illustrative comparisons—those serving not for intellectual comprehension, but for ornament, effect, or emotion. I have said that Bacon's ■comparisons rarely grew out of a poetic choice, though, from their reach, their aptness, and their occasional picturesque- ness, they might sometimes be quoted as a kind of poetry. His purpose was to enlighten, not to adorn. But similarity is the instrument of adding ornament and force to compositions : when an idea or picture is intended to kindle emotion of any kind, the effect can always be heightened by adducing illustrative comparisons more impressive than the original. When Sir Philip Sidney, to describe the moving effect of the ballad of ' Chevy Chase,' says that it stirs the heart ' like the sound of a trumpet,' he enforces a weaker impression by one much stronger as well as more familiar. The following lines of Chaucer contain two exquisite comparisons for enriching the emotional effect of the subject — they are part of his ■description of the youthful Squire : — Embrowded was he, as it were a mede, Alful of fresshe flourts, white and reede. Syngynge he was, or floytynge, al the day ; He was as fressh as is the ynoneth of May. To find powerful and touching comparisons in keeping with a subject, is one of the constant endeavours of the poet, and puts his genius to the severest test. The same demand is made upon the orator, —who has besides to stir up the emotions of his audience, to kindle their likings and dislikings with the view of moving them in some one direction. Hence, in RHETORICAL FIGURES OF COMPARISON. 563 oratory of every kind, we find abundant use of the figures of speech growing out of comparison. In panegyric, elevating simihtudes are employed ; in denunciation, such as degrade. Derision and merriment grow out of low, grovelling compari- sons applied to things pretending to be dignified and vener- able. Burke's French Bevolutiou teems with all the varieties of eloquent comparison. His ' trampling law and order under the hoofs of the swinish multitude,' will be ever memorable among the figures of oratory. While Shakespeare displays Bacon's power of illumina- tive comparison, especially in moral maxims and common- places, he shines chiefly in the other class, those that heighten the emotional effect ; while the genius of both the one and the other abounds in such as have no effect what- ever but intellectual profusion. With extraordinary suscep- tibility to the sensible and concrete of the world, to the full face of nature and life, Shakespeare had, although not in the highest measure, the poetic eclecticism, and dwelt bj' prefer- ence upon the objects that inspired such emotions as an artist is wont to kindle up. He had, perhaps, the greatest intellectual reach of Similarity on the whole that the mind of man ever attained to ; and his power of adducing illus- trative similitudes, through chasms of remoteness and the thickest disguises, will be a wonder and an astonishment to the latest posterity. 43. Of the Tropes and Figures described in Rhetoric, the larger part turn upon comparison. The metaphor, the simile, the allegory — are all forms of illustration by similitude, sometimes serving for clearness, or intellectual comprehen- sion, at other times producing animation and effect. The invention of them is due to the identifying intellect — which breaks through the partition caused by difference of subject, to bring together what is similar. The literary and poetic genius of ages has accumulated a store of such comparisons ; many of them have passed into common speech to enrich the dialects of everyday life. No man has ever attained rank in literature, without possessing in some degree the power of 564 AGEEEMENT — LAW OF SIMILARITY. original illustration ; and the interval of disparity broken through is a fair measure of the intellectual force of the individual mind in one of the leading characteristics of genius. The original fetches of Homer, of ^schylus, of Dante, of Milton, and, above all, of Shakespeare (I do not pretend to exhaust the list even of the first-rate minds), are prodigious. How remote, and yet how grand, the simile describing the descent of Apollo from Olympus: he 'came like night'. The identifying faculty, be it never so strong, would hardly suftice to bring together things so widely different, but for some previous preparation, serving to approximate the nature of the two things in the first instance, as we have already had occasion to remark of some of the scientific discoveries. Night itself had to be first personified to a certain extent, thereby reducing the immense disparity between the closing day and the march of a living personage down the mountain slopes. Apollo was, besides, the god of the sun. THE FINE ARTS IN GENERAL. 44. The observations now made respecting Poetry apply with some modification to the Fine Arts generally. In the Arts, we may trace out a scale or arrangement, beginning at the most intellectual and ending with those that have this quality in the lowest degree. At one end of the scale, we find distinct examples of the purely intellectual law of simi- larity ; at the other end, scarcely a trace of this operation appears in the form that we have been accustomed to. Poetry, Painting, Sculpture, Architecture, Decoration, and Design, are all conversant with some of the higher intel- lectual elements : Poetry with speech, and the pictorial as represented by speech, the others with visual forms and appearances of various kinds. In storing up, and on fit occa- sions reproducing the materials of those arts, the associating forces of Contiguity and Similarit}^ are extensively brought into play. As to Contiguity, this is obvious enough ; as regards Similarity, it may be easily shown. A painter in composing a picture must, in the last resort, choose the THE INTELLECTUAL FINE ARTS. 565 component parts, according to their artistic keeping with one another : but, in recalHng from the past a number of objects, in order to try their effect, he will be greatly assisted by a powerful identifying faculty. We may suppose him to have in his mind some one plan of a background, — which back- ground, however, although containing the main features, does not satisfy his artistic sense. By the attraction of likeness, this part, unsuitable in itself, may recall others resembling and yet greatly differing, and, in the array brought up by a powerful intellect, working upon a large foregone experience, some one may be presented answering the re- quirements of the picture. There may be nothing artistic in the suggestion of the different views ; nevertheless, it is only an artist that can make the proper choice. As in poetry, so in painting, in sculpture, in architecture, decoration, and design, there may be a rich intellectual storage and repro- duction of the material, apart from the aesthetic feeling ; although, by this feeling, the artist must be guided in the use that he makes of the suggestions of the intellect. In all the Arts, examples may be found of rich profusion of unse- lected matter ; the artist mistaking a strong recollection and revival of natural scenery and pictorial elements in general for the artistic harmonizing of the material ; still, in the de- partments we are now discussing, no one can attain the highest greatness without some intellectual source of sugges- tions over and above his artistic faculty. The intervention of high intellect in Art seems to have reached a climax in Michael Angelo ; and the limits of human nature forbid us' to suppose, that he could at the same time exert the power of delicately adjusting the parts of his compositions, so as to yield the graces and charms that constitute the true distinc- tion, the essence, of Art. 45. When we pass to the second class of Arts, we find intellect dying away and giving place to the genuine artistic stimulus in its purity. Music is the most conspicuous mem- ber of the group, and might be taken as representing the whole : the others are, spoken music or Eloquence, Dramatic 566 AGREEMENT — LAW OF SIMILARITY. action and Pantomime, the graces of personal Demeanour and displaj', and the Dance. In these Arts, the suggestions of intellectual similarity can hardly be said to occur. Undoubt- edly, we may by similarity, as already said, identify a common character in different airs and harmonies ; and, through the presence of any one, others may be recalled to the mind of a composer, and may serve him as hints and aids in a new composition. In such circumstances, I can conceive the operation of a vigorous identifying faculty as enlarging a musician's resources, or as making more readily available to him the examples that have previously impressed themselves on his mind. But this process of imitating and compiling does not fairly exemplify the workings of artistic creativeness. The author of a truly original melody relies upon no such intellectual assistance. By the spontaneous gushings of his mind he flows out into song, and by the guidance of a delicate sense he tunes himself to melody. Other men may imitate and combine such primitive originals in a variety of compo- sitions, but the knowing ear can always detect the work of compilation. Intellect may originate Science, but not Art. There is also the case of strictly imitative music — as when Haydn, in the ' Creation,' tries to reproduce all the sounds of nature. But no good judge ever puts music of this kind high . I may here refer to what is a common subject of remark, that great musicians and actors, not to speak of opera dancers, have often a verj^ low order of intellect, as measured by the ordinary tests. So, in the charms and graces of society, which are a species of fine art, intellect may contribute nothing. On the other hand, in assisting the less gifted temperaments to take on the charm native to the others, it may operate with good effect ; for this is done by acquisition and compilation, where the intellectual forces always work to advantage. Moreover, in Art, effects can often be reduced to rule, and the comprehending and following out of rules is an affair of the intelligence. In musical compositions, there are rules as to harmony, which any one might act upon ; in elo- ACQUISITION BY PIECING PREVIOUS ATTAINMENTS. 567 cution, much can be done by merely understanding the direc- tions of an instructor ; and, to stupidity, all such directions are nugatory. Thus it is that, in the diffusion and extension of the least intellectual of the fine arts, recourse may be had to an instrumentality that would never suffice for their creation. It is a remarkable fact in history, that the most highly gifted people of antiquity, in all that regarded pure intelligence, had apparentlj' no originality in music, although they could appreciate and borrow the melodies of foreign nations, and employ these to accompany their lyric and dramatic compositions. SIMILARITY IN ACQUISITION AND MEMORY. 46. It now remains to show how the force of reinstate- ment by Similarity can operate in carrying forward the work of Acquisition. We have seen that the associating principle of Contiguity must needs be the groundwork of Acquisition in general ; but when any new train can bring up, from the past, some nearly similar train, the labour of a separate acquirement is thereby saved : the points of difference be- tween the new and the old, are all that is left for Contiguity to engraft on the mental system. When a workman is to be taught a new operation in his art, there will necessarily be, along with certain matters of novelty, a large amount of identity with his already acquired habits ; hence, in order to conquer the operation, he will require to repeat it just as often as will suffice for fixing, by the plastic operation of Conti- guity, all those original steps and combinations. A professed dancer learning a new dance, is in a very different predica- ment from a beginner in the art. A musician learning a new piece, actually finds that nineteen-twentieths of all the sequences to be acquired have been already formed through his previous education. A naturalist reads the description of a newly discovered animal : he possesses already, in his mind, the characters of the known animals most nearly approaching to it ; and, if he merely give sufficient time and attention for the coherence of the points that are absolutely 568 AGREEMENT— LAW OF SIMILARITY. • new to him, he carries away and retains the whole. The judge, in listening to a law-pleading, hears little that is absolutely new ; if he keeps that little in his memory, he stores up the whole case. When we read a book on a subject already familiar to us, we can reproduce the entire work, at the expense of labour requisite to remember the additions it makes to our previous stock of knowledge. So in Fine Art ; an architect, a painter, or a poet, can easily carry away with him, the total impression of a building, a picture, or a poem ; for, instead of being acquisitions de novo, they are merely variations of effects already engrained in the artist's re- collection. To whatever extent one thing is the repetition of another, the cost of contiguous acquisition is saved. But it is neces- sary that the repetition or identity should be perceived ; in other words, the new lesson must reinstate, by the force of Similarity, all the previous trains that in any way correspond with it. An old acquirement containing many steps in com- mon with a lesson in hand, will be of no use unless it is recalled ; should the disagreeing points be so marked, as to cloud a resemblance and stifle the identifying action, no- thing is gained by the agreement. It consequently happens, that a mind, feeble as regards the restoring force of similarity, misses the help that past acquirements could often bring to bear upon present efforts ; whereas a remarkable energy of recall will make everything available that contains the smallest trace of common matter. 47. To take a few examples from Science. The subject- matter of Geometry embodies a few fundamental notions and processes. A definition, an axiom, a postulate, a proposition, whether theorem or problem, a chain of demonstration, are to the beginner things absolutely new. They must be fixed by the plastic power of Contiguity, and time and concentration must be allowed for the purpose. But, in a good head, one or two examples of each, strongly imprinted, will make all the rest easy : the method or character of the devices will be seen through and acquired, and, in every new case, the mind will ACQUISITION IN SCIENCE SHORTENED. 569 fall back upon the old ones, for the common element, and concentrate attention on the points of difference solely. When, after going over a few definitions, the learner is im- pressed with the form and peculiarity of a definition, there is little to acquire in the rest : a slight substitution serves to make a new one out of an old ; the definition of a square is easily changed to suit a rectangle. So with an axiom : the first is the most laborious to acquire ; every subsequent one is easier than the preceding. When we come to the proposi- tions, there is a very great deal of novelty at first ; the whole scheme and management of a theorem or problem — the for- mality in the statement, and in the order of the proof — are things utterly strange to the young beginner ; to acquire a simple proposition is a heavy strain upon his adhesiveness for abstract and representative forms. When this last acqui- sition is made, it can be turned to account in every succeeding proposition, provided the operation of similarity is not ob- structed by the differences that encumber the new cases. Indeed, if each step in the machinery of Geometry were, without much waste of time, firmly learned on the first •encounter, and if the reviving power of similarity for this class of things vv^ere unfailing, one's progress through Euclid would be a race, such as is recorded of Pascal and Newton. But, to the generality of minds, identities in geometrical reasoning are hard to perceive ; a difference in collaterals utterly extinguishes the feeling of a similarity in substance, and every new proposition is a fresh labour — as if nothing like it had been gone through before. What is true of Greometry holds in all the sciences. There is, in each, a vast deal of repetition both of the facts, or subject-matter, and of the formal machinery, although 'with great differences of mode and circumstance. The law of gravitation runs through all Astronomy ; and, in the deepest calculations of the celestial movements, the same mathe- matical devices are constantly reproduced in new complica- tions. A mind that can seize a calculation once for all, and trace it out in the thickest envelope of diversity, will speedily 570 AGEEEMENT — LAW OF SIMILARITY. pass through the intricacies of this vast subject, or of any- abstract science. With such a reach of similarity as can suffice to trace out identities hitherto passed over by all former minds working in the same sphere, it is to be presumed that the more ordinary resemblances will be easy to strike ; hence an original mind in science is also distinguished for the rapidity of its course along the track of the already known. Much of the acquisitions of a strong intellect are in reality the re-discovery of what .is already known ; such an intellect perceives the identities of abstraction, classification, induction, deductive application, and demonstrative reasoning, even before they are pointed out by the master. He will make but a poor mathematician that needs to refer to his book for the demonstration of every successive theorem. To all branches of Physics, to Chemistry and Physiology, the very same remarks will apply. It is the nature of an advanced science, to contain innumerable identifications summed up in its definitions and general laws ; it was by a vigorous similarity that these were first formed ; by the same power they are rapidly acquired. So in the more concrete sciences of thie "Natural History group. In Zoology, Botany, Mineralogy, Geology, there has been accumulated a fund of identities in the classifications made of the objects of each. To acquire these classifications, the learner must himself feel the similarity among the indi- viduals ; and, if his mind is of that powerful kind that can trace many of the likenesses by its own unassisted force, he will speedily string together all the groups that have been formed by others. It is of consequence to a botanist, looking at a new plant, that he shall be able to recall at once what- ever other plants he has known that in any points resemble it : he will, in this way, both determine its true class, and stamp it with ease upon his memory. 48. In all the acquisitions of Business, Similarity will likewise bear an important part. If an apprentice at the Law has that deep and subtle identifying power that sees, in every new case, whatever similarity there is in it to some ARTISTIC ACQUISITIONS SHORTENED. 571 previous one, he saves half his labour ; his mind breaks in upon the old track, and on that builds up the new recollec- tion to the extent of the likeness. It is possible to lay under contribution in this way matters far removed from the subject in hand : one may clench the technicalities of the law, by falling back upon one's miscellaneous knowledge ; we may recur to recollections out of all sciences and arts, illustrating the subject as it were to one's self. The mind of Lord Bacon could see in anything before him multifarious analogies to things the most remote ; these analogies he could produce to his readers to facilitate their conception of his meaning, and, by the same power, he could shorten his own labour and study. When a clever person surprises us, by instantaneously comprehending and firmly retaining some new method of procedure, we may be quite sure that it has taken hold of him, by resuscitating something analogous out of the store- houses of bis past experience : whenever this easy compre- hension, and this permanent retention, form part of the mental character, and show themselves in a wide range of subjects, there is sure to be at bottom a vigorous identifying faculty. 49. The case of the Artistic mind presents no essential difference. The storing up of impressions of objects of art is easiest when the identifying power is so strong as to bring up, on every occasion, whatever resembles the object before the view. That a likeness should exist between something we are at present looking at, or listening to, and some past impressions on the eye or the ear, and that that likeness should not be felt, is a misfortune, a loss in every way ; and, for this reason, among others, that, to impress the new object on the memory, we need as much repetition and pains, as if nothing of the kind had ever been experienced before. In reading a poem, the memory is assisted to remember it by all the similarities of thought, of imagery, of language, of metre and rhythm, that one is able to evoke from the traces of former readings and recollections. In a mind keenly sus- ceptible to all these poetic elements, and having the power 572 AGEEEMENT — LAW OF SIMILAEITY. of similarity highly manifested, almost every touch will rouse up something from the past that has a certain degree of resemblance ; and that something will be an already formed recollection, to eke out the retentiveness of the new strain. The more one's acquisitions advance, the greater the scope for this work of fitting old cloth into new garments; but previous acquisition is of avail, only according as the stroke of resusci- tation is good, and is able to pierce the disguises of diversity and altered form attaching to past examples. 50. The retentive power of the mind is not thoroughly tested, except by entire and absolute novelty — a thing that is more and more rare as one grows older. In learning languages, for example, we have less to acquire with every new individual language. Latin prepares for French, Italian, Spanish, etc. ; German for Dutch ; Sanscrit for Hindostanee. The generalizations of philologists in tracing common roots through all the Indo-European tongues, greatly diminish the number of original ties that contiguity has to fix. All dis- coveries of generalization have this effect ; and if an individual learner can see likenesses, m addition to what have been already promulgated, his labour is shortened by strokes of power peculiar to himself. The learner of the Latin rudiments on entering the four conjugations of the verb soon discovers, in passing from one conjugation to another, that there is far more similarity than difference. Making use of this observation as a means of shortening his labour, he has merely to take note of the specialities of each separate conjugation, and, when he has mastered these, his task is completed. 51. The Historical Memory might furnish good examples of the intervention of Similarity, in making up the coherent tissue of recollected events. In the transactions of the world, great and small, there is so much of repetition, that a new history is in reality a various reading of some old one ; not to mention how much each nation repeats itself through its successive epochs. To a dull mind, a large amount of this repetition is lost for all purposes, the aid to memory among THE HISTORICAL MEMORY AIDED. 573 the rest ; but a keen-sighted attraction for every vestige of recurring hkeness enables one to retain large masses of narrative, at a small expense of adhesive acquisition. Cam- paign suggests campaign, and one battle another ; an intrigue, a negotiation, a career of ambition, a conquest, a revolution, are things familiar to the student gone some way in history ; only certain minor features, some of the proportions and cir- cumstantials, are special to the case in hand, and require to be fixed in the memory by pure contiguity. No man could recite a narrative of any sort from a single reading or hearing, if it were all new to him : to tell a story, an hour after hearing it, would be impossible, but for our already possessing, among our stored recollections, more than nine-tenths of all the adhesions that enter into it. In addition to the historical memory, we might quote the recollection of our Past Life, which depends partly upon contiguous bonds of succession in time, but which is largely and frequently dependent upon strokes of Similarity. Some present incident will revive former incidents of a like charac- ter, at whatever times they may have occurred. In this way, we supply the numerous hiatuses that would be left if we were dependent entirely upon the chronology of dates as held together by mere contiguity. A startling example under this head may be quoted from the play of ' Hamlet,' at the point where Hamlet arranges a theatrical scene to bring home to his guilty uncle's mind with terrific force the circumstances of his father's murder. CONCLUDING OBSERVATIONS. 52. The following general observations will complete the copiously detailed survey that has been given of this very large portion of our intellectual workings. The faculties implicated in the operation of similarity have been brought out in the course of the exposition. Everything pertaining to tne Eeasoning power essentially demands the identification of like in the midst of unlike. This 574 AGEEEMEXT — LAW OF SIMILARITY. ouo;ht now to be distinctly apparent. Of course contiguous growths are very largely required in building up our reason- ing powers ; but, with these alone, the sweep of generalization that reproduces the vastness of nature, under a comparatively limited range of notions and propositions, would have been impracticable. It must be equally obvious, that the so-called power of Imagination, which, in its peculiar sphere, rivals in amplitude the domain of reason, would be bereft of all its force and character, but for the workings of similarity as developed in the rarest examples of its endowment. 53. The question has been incidentally started — whether there be a power of General Similarity, apart from and above those local endowments that have been assumed to aid its workings, and to constitute individual differences in the reach that it attains. It was a much easier inquiry to ascertain the existence of a general power of Contiguity, favoured as it also is by delicately constituted sense endow- ments. The difficulty in the present case is, that in a stroke of similarity under diversit}', there is a conflict or fight of opposing attractions. Now, a supposed augmentation of the power in general would tell upon all the items of the present complex, in the act of evoking some one of its re- sembling aspects. Thus, if it were a question of revi\ang a coincidence in verbal form under diversity of meaning and other circmnstances, the increase of general power would operate, not upon the language alone, but upon the meanings as well, so as to strengthen the force of resistance to the verbal recall. Doubtless, something of this kind would be inevitable, as a part of the operation, yet without bringing about that exactly equal contribution to all the elements of the complex that would neutralize the benefit of a supposed general superiority in the attraction of Simi- lars. 54. Considering all that has been advanced as to the bearing and importance of this great power, we are in- terested in knowing how far, and by what methods, it may POWER OF SIMILARITY SCARCELY IMPROVABLE. 575 be cultivated or improved. Of course, looking at the three local conditions that have been kept constantly in view, viz. — delicacy of sense, previous acquirement, and habit of attention, we must admit the possibility of improvement, inasmuch as all these peculiarities are within the sweep of the plastic force of Contiguity. As regards the general power just adverted to as outside of these, if its existence be problematical, still more so is its artificial cultivation or improvement. Indeed, there is something of a paradox in extending the process of strengthening or improving any power that is not included in the sweep of Eetentiveness or Contiguit}' as already defined. It is safer to regard the attractive force of Similarity in diversity as a natural en- dowment per se, whose variations of degree in the same individual, at different times of life and under different circumstances, are probably referable to some one or more of the conditions proper to the plastic or contiguous bond. There is a common saying of advanced age that, though memory begins to fade, judgment remains good and even goes on improving. This vaguely expresses a fact that is probably true — namely, that while plasticity is shown to be weaker by the slowness of new acquisitions, the flash of similarity between the new and the old is as ready in later years as in early, until such time as the brain itself becomes abnormally weak, in a way that years alone would not suffice to account for. It has been noted, in some remarkable cases, that the freshness, force, and opulence of imaginative crea- tiveness grows, instead of diminishing, with the advance of years. Bacon, Milton, and Burke are conspicuous instances in point. The art of Education, in its full compass, comprises the means of improving powers and processes implying Simi- larity, no less than Contiguity. The considerations, how- ever, that are brought to bear in this instance have reference mainly to the modes of giving fair play to the powers generally, by physical aids, and the removal of distraction, obstruction. 576 AGREEMENT — LAW OF SIMILARITY. and the various causes of relaxed attention. The teaching of a proposition of Euchd would exemplify and embrace the artificial assistance to the reasoning faculty of the learner, just as instruction in language would give scope for the devices that aid the memory. CHAPTEE III. COMPOUND ASSOCIATION. 1. TTITHERTO we have restricted our attention to single i-L threads or indivisible links of association, whether of Contiguity or of Similarity. It remains for us to consider the case where several threads, or a plurality of links or bonds of connexion, unite in reviving some previous thought or mental state. No new principle is introduced here: we have merely to note, what seems an almost unavoidable effect of the combined action, that the reinstatement is thereby made more easy and certain. Associations that are individually too- weak to operate the revival of a past idea, may succeed by acting together ; and there is thus opened up to our view a- means of aiding our recollection, or invention, when the one thread in hand is too feeble to effect a desired recall. The combinations may be made up of contiguities alone^ of similarities alone, or of contiguity and similarity mixed. Moreover, we shall find that, in Emotion and in Volition, there are influences either assisting or obstructing the proper intellectual forces. In the reviving of a past image or idea, it is never unimportant, that the revival gratifies a favourite emotion, or is strongly willed in the pursuit of an end. We must endeavour to appreciate, as far as we are able, the influence of these extra-intellectual energies within the sphere of intellect ; but, as they would rarely suffice for the repro- duction of thought, if acting apart and alone, we are led to look at them chiefly as modifying the effects of the strictly intellectual forces, or as combining elements in the composi- tion of associations. 37 v578 COMPOUND ASSOCIATION. The general law may be stated as follows : — Past actions, sensations, thoughts, or emotions, are re- called more easily, when associated, either through contiguity or through similarity, with more than one present object or impression. COMPOSITION OF CONTIGUITIES. 2. We begin with the composition of contiguities. In- stances might be cited under all the heads of the first chapter ; but a less profuse selection will suffice. There will, however, be a gain in clearness by taking Conjunctions and Successions separately. Conjunctions. — For a simple example of a compound con- junction, we may suppose a person smelling a liquid, and identifying the smell as something perceived before, but unable to recall to mind the material causing it. Here, the bond between an odour and the odorous substance is too feeble for reproducing the idea or the name of the substance. Suppose, further, that the person could taste the liquid without smelling the odour, and that, in the taste, he could recognize a former taste, but could not remember the thing. If, in these circum- stances, the concurrence of the two present sensations of taste and smell brought the substance to the recollection, we should have a true instance of composite association. If, however, one of the two links is fully equal to the restoring effect, there is no case under the present law : in order to constitute a proper example, each should be insufficient when acting singly. Although there can be no doubt as to the fact of such revivals, we might easily suppose it otherwise. Combination is not strength under all circumstances. A gallon of water at 40^ cannot yield a spoonful at 41°. Ten thousand common- place intellects would not make one genius, under any system of co-operation. The multiplication of unaided eyes could never equal the vision of one person with a telescope, or a microscope. The case of obtaining a new or additional link, in itself suf- CONJUNCTIONS COMBINED. 579 ficiently powerful to effect the recall, is frequent enough. Indeed, it occurs so often as to render the essential position of composite contiguities somewhat difficult to establish. Failing to recover a name, for example, in connexion with an object or a person, we may direct the thoughts into some other train where it is placed and can occur with ease. The active search for an alternative linking when we happen to be nonplussed, may land us sometimes in an independently sufficing bond, and sometimes in a mere co- operating one. The general fact that two different links, each in- sufficient of itself, may succeed by concurrence may be held as established by a wide induction, notwithstanding the frequency of the case now supposed. We have seen that the complex loholes around us in the world, are held together in the recollection by the adhesive force of Contiguity : such objects as a tree, a human figure, a scene in nature, cannot continue in the mind, or be revived as ideas, until frequent repetition has made all the parts coherent. After the requisite iteration, a complex object, such as a rural village, may be revived by the presence of a single portion of it, as some street, or building, or marked locality. But, if the village is one not very well known, — that is, if the notion of it is not very firmly aggregated in the mind, — the traveller just entering may not be ready to identify it by the first thing that strikes him ; he may require to go on till several other objects come in view, when probably their joint impression will be able to bring up the whole — in other words, will remind him what village he is now entering. So, in regarding objects as concretes, or combinations of many distinct qualities — an orange, for example, which affects all the senses, — a fixing process makes the different sensations hold together in one complex idea. Here, too, there is room for the joint action of associating links in re- calling an image to the mind. I have already imagined a case of this description, where the united action of smell and of taste was supposed to revive the idea of the concrete 580 COMPOUND ASSOCIATION. object causing them, either being of itself insufficient for the purpose. 3. It is, however, when we go beyond the case of isolated objects, to the still greater aggregates made up by the rela- tions of things to one another, that we can reap examples of multiple association in the greatest abundance. In the con- nexions of objects with places, with persons, with uses, and with properties, we see numberless occasions for the working of the composite link. When things have a fixed locality, they become associated in the mind with that locality, or with a number of com- panion objects or appearances. This is one of the means of their restoration to the mind in idea. The sight or remem- brance of a harbour recalls the shipping ; the recollection of a building brings up its known contents. Conversely, an object that has a fixed place recalls the place, — as when St. Paul's reminds us of the neighbourhood where it stands. Now, it not seldom happens, that we desire to recall a place or an object by this single link of connexion, but are unable to do so ; a concurring bond may then be brought to our aid. Thus, to take the case of searching for things lost. When we do not know where to find a thing that we ourselves have put in its place or seen there, the adhesion of place is by that circumstance shown to be feeble. We then run over other links of association — the time when we last saw it ; the work we were engaged in ; or any fact that would have an association with the forgotten place : we may thus, through a multiplicity of feeble connexions, attain a force of recall equal to one sufficiently strong adhesion. The connexions with persons frequently prove an assisting link in difficult recollection. Objects become associated with their owners, their makers, their inventors, all persons con- cerned in their use, or frequenting their locality. When we are unable to recover a thing, by the adhesion between it and other inanimate accompaniments, a personal connexion will often make up what is wanting. Thus, in my endeavour to COMPOSITE ASSOCIATIONS WITH PERSONS. 581 recollect an array of objects in some museum, there are some that have completely escaped me : the association of these with their place in the building, and with the adjoining objects, is not enough ; but, when I chance to recall the donor, the collector, or maker, along with these other ad- juncts, the vanished individuals may be made to re-appear. It happens, likewise, that things are recalled by plurality of association wath persons ; each link being too weak alone, but made powerful by union. I meet some one in the street, and make an ineffectual attempt to remember where I last saw the saine person : by and by, some one else occurs to me, who was present on the occasion. Perhaps, if I had merely this last person in my view, I should have been as little able to revive the meeting as with the first alone; whereas, with the two, I have no longer any difficulty. The converse operation of remembering a person by two or more different connexions is still more frequently exein- plified. A human being is a sufficiently manj^-sided object to be open to revival through a multiplex bond. Whether regarded as an aggregate of many parts, or as a concrete of many qualities, the remark Jiolds to a great degree. The particulars of a personal description are very numerous, and it often requires many of them to be cited, in order to bring to mind an individual very well known to us. Moreover, the ei'ternal relations of human beings surpass in variety those of other objects. Persons are associated with their name ; with locality, habitation, and places of resort ; with blood and lineage — a very powerful mental tie, m consequence of the strength of the family feelings ; with associates and friends; with occupation, pursuits, amusements ; with pro- perty and possessions ; with rank and position ; with the many attributes that make up character and reputation ; with a particular age ; with the time they have lived in ; with the vicissitudes and incidents that mark the course of their life. Now, in recalling some individual to mind, some one or more of these connexions will serve ; and, when a present link is insufticient, others may be added. If we 582 COMPOUND ASSOCIATION. were endeavouring to recover the historical personages of a given time — the age of Pericles, for example, — there would he a certain strength of bond between each of them and the idea of the time, — namely, the fifth century before Christ. In the case of some, this link might be strong enough of itself; with others, a second link might be requisite, — as, for instance, their profession. With the idea of a sculptor entering into the combination, we should recall Phidias ; with a painter, Zeuxis ; with a philosopher, Anaxagoras. Our historical memory is frequently helped after this fashion. 4. The connexion of things with uses is a source of mul- tiple bonds. A machine, a building, the materials of food, clothing, etc., whatever comes into the market as a useful commodity, an army, or a fleet, — all such things have, besides their appearance, locality, ownership, etc., a distinct end to serve ; whence arises a powerful bond of association. If I am unable to remember the objects that I have seen in a certain shop, by virtue solely of their association with the shop, and with contiguous things that I do remember, one course open to me would be to run over in my mind a list of utilities to be answered ; in which list I should bring up one or more uses of the forgotten things, and the new bond co-operating would be sure to recover some of those from their oblivious condi- tion. To carry awa}' a full recollection of the contents of a workshop that I have visited, I should find it necessary to aid the associations of contiguity of place and succession with the various ends or utilities that were to be suited. In the natural sciences, the material objects of the world are looked upon as having many properties, useful or not : these are ascertained by observation and experiment, and are recorded as part of the description of the several substances. In this way, everything suffers an ideal expansion or aggran- dizement in the mind ; the connexions of things, or the threads that give us our hold of them, are multiplied. The substance, silica, in the mind of a naturalist, has a vast range of associations in consequence of the many properties entering into his notion of it. These various links tend to OBJECTS WITH THEIR PROPERTIES. 58'S- bring the substance repeatedly before the mind : sometimes, one link is sufficiently powerful — as, for example, the recol- lection of a given degree of hardness ; at other times, the material is recoverable by double or triple connexions — as the ideas of an oxide, of insolubility, and of a six-sided crystallization. The scientific man's memory is constanth'- aided by the multiplication of bonds indi^ddually too feeble to bring about the recollection of something absent. In invention, or in the search for a new device to answer some end, the mind must go over catalogues of objects according to many kinds of contiguity, including the most casual connexions. 5. Successions. — I have dwelt at length, in a previous chapter, on the contiguous association of successions of various kinds. Here, too, in the circumstance of imperfect adhesion, the recovery may be due to a composite action. A series of events actually witnessed would, in consequence, possess a certain amount of adhesion. In the endeavour to recall the series from the commencement, a link may fail, while some second association, such as place or person, con- tributes a strengthening bond. There is one succession that contains the whole of our experience, — that is, the Order of Time, or the sequence of events in each one's own history. If all the minutias of this succession were to cohere perfectly in the mind, everythmg that we have ever done, seen, or been cognizant of, could be recovered by means of it. But, although all the larger trans- actions and the more impressive scenes of our personal history are linked in this order with a sufficient firmness, yet, for smaller incidents, the bond is too weak. I cannot remember fully my yesterday's doings ; nor repeat verbatim an address of five minutes' length, whether spoken or heard. Things related in the order of time are, strictly speaking, experienced only once ; and we usually require repetition to fix any mental train. It constantly happens, therefore, that we are in search of some reinforcing connexion to help us ni recovering the stream of events, as they occurred in the 584 COMPOUND ASSOCIATION. order of time. We seek for other conjunctions and succes- sions to enable us to recommence after every break. Experience teaches us, that the only way of making up a defective adhesion is to compass in ouv minds some other connexion, or to get at the missing object through a new door. The inability to recollect the next occurring particular of a train that we are in want of, stimulates a great effort of volition, and the true course for the mind to take is to get upon some chain or current that is likely to cross the line of the first near the break. At every moment of life, each person stands immersed in a complicated scene, and each object of this scene may become a starting-point for a train of recollections. All the internal feelings of the body ; everything that surrounds us and strikes the eye, ear, touch, taste, or smell ; all the ideas, emotions, and purposes occupying the mind, — these form so many beginnings of trains of association passing far away into the remotest regions of recollection and thought ; and we have it in our power to stop and change the direction as often as we please. From some one of these present things, we must commence our outgoings towards the absent and the distant, whether treading in single routes, or introducing composite action. 6. Language. — The recall of names by things, and of things by names, gives special occasion for bringing in addi- tional links to aid a feeble tie. When we have forgotten the name of a person, or of an object, we are under the necessity of referring back to the situation and circumstances where we have heard the name, to see if any other bond of connexion will spring up. Often we are unable, at the moment, to recover the lost sound by any means ; but, afterwards, an auxiliary circumstance crosses the view, and the revival is effected. Many of our recollections, thoughts, conceptions, and imaginings, are, an inextricable mixture of language and ideas of things. ,' The notions that we acquire through oral instruction, or from books, are made up in part by the LANGUAGE RECALLED BY COMPOSITE BONDS. 585 subject-matter purely, and in part by the phraseology that conveyed it. Thus, my recollection of a portion of history is made up of the train of words, with the train of historical facts and scenes, as I might have witnessed them with my own eyes. So, in many sciences, there is a combination of visual or tactual notions with language. Geometry is a compound of visible diagrams with the language of definitions, axioms, and demonstrations. Now, in all these cases, recollection may depend, either on the associations of words, or on the associations of visual and other conceptions, or on a com- pound of both. If I listen to a geographical description, there is, in the first place, a train of words dropping on my ear ; and, by virtue of a perfect verbal cohesion, I might recall the whole description and recite it to another person. In the second place, there is a series of views of objects — of mountain, river, plain, and forest — which I picture in my mind and retain independently of the language used to sug- gest them. Were my pictorial adhesion strong enough, I could recall the whole of the features in the order that I was made to conceive them, and dispense with the language. The common case, however, is that the recollection is effected by a union of both the threads of cohesion : the pictorial train is assisted by the verbal, and the verbal by the pictorial, as may happen. COMPOSITION OF SIMILARITIES. 7. The influence of the multiplication of points of likeness, in securing the revival of a past object, is liable to no uncertainty. It is only an extension of the principle main- tained all through the discussion of the law of similarity, that the greater the similitude, and the more numerous the points of resemblance, the surer is the stroke of recall. If I meet a person very like some one else I have formerly known, the probability of my recalling this last person to view is increased, if the likeness in face and feature is com- bined with similarity of dress, of speech, of gait, or of any still more extraneous points, such as occupation, or history. 586 COMPOUND ASSOCIATION. Increase of resemblance extensively — that is, by outward con- nexions — has the same power as increase of resemblance intensively, in rendering the restoration of the past more certain. It might admit of a doubt whether four faint links of contiguous adhesion would be equal to one strong, but it would be against our whole experience of the workings of similarity, to doubt the utility of multiplying faint resem- blances, when there was no one sufficiently powerful to effect the revival. At the same time, we must allow that much more is contributed to the chances of reinstatement by intensifying one point of likeness, than by adding new ones of a faint character. By raising some single feature almost up to the point of identity, we should do more good than could be done by scattering faint and detached likenesses over the picture. This, however, is not always in our power ; and we are glad to find that, when the similarity, in any one particular, is too feeble to suggest the resembling past, the existence of a plurality of weak resemblances will be the equivalent of a single stronger one. On this view, I might set forth the workings of compo- site similarities, from the various classes of examples gone over in the preceding chapter. In all very complicated con- junctions — as, for example, a landscape, — there may be a mul- tiplication of likenesses, unable to strike singly, but, by their concurrence, suggesting a parallel scene. Hence, in en- deavouring to recall resembling things, we may proceed, as in Contiguity, by hunting out new collaterals, on the chance of increasing the amount of similitude, and, with that, the attractive power of the present for the absent. If I am endeavouring to recall to mind some historic parallel to a present political situation, supposing one to exist and to have been at some former time impressed on my mind, there may be a want of any single salient likeness, such as we admit to be the most effective medium of reinstatement ; and I must, therefore, go over in my mind all the minute features of the present, to enhance, in this way, the force of the attraction of similitude for tlie forgotten parallel. INCREASED AMOUNT OF SIMILARITY. 587 8. The case noticed at the conclusion of the preceding head — namely, the combination of language with subject- matter in a mixed recollection — is favourable to the occurrence of compound similarity. If an orator has to deal with a special point — the conduct of an individual, for example, which he wishes to denounce by a cutting simile — his inven- tion may be aided by some similarity in the phrases descrip- tive of the case, as well as in the features of the case itself. If one who has at a former time read the play of (Edipus, now commences to read Lear, the similarity is not at first apparent ; but, long before the conclusion, there will be a sufficient accumulation of features of similitude, in dramatic situation and in language, to bring CEdipus to mind without any very powerful stretch of intellectual force. So, in scien- tific invention : a fact described in language has a double power of suggestion ; and if, by good luck, the fact has a likeness to some other fact, and the description resembles the language that accompanied that other when formerly present to the ndnd, there is so mucli the more chance of the revival taking place. MIXED CONTIGUITY AND SIMILARITY. 9. Under this head, there are several interesting examples. If any one, in describing a storm, employ the phrase ' a war of elements,' the metaphor has been brought to mind partly by similitude, but partly also by contiguity, seeing that the comparison has already been made. The person that first used the phrase came upon it by similarity; he that used it next had contiguity to assist him; and, after frequent repetition, the bond of contiguity may be so well confirmed, that the force of similarity is entirely superseded. In this way, many things that were originally strokes of genius, end in being efforts of mere adhesive recollection ; while, for a time previous to this final consummation, there is a mixed effort of the two suggesting forces. Hence Johnson's remark 588 ■ COMPOUND ASSOCIATION. on the poet Ogilvie,— that his poem contained what was once imagination, but in him had come to be memory.* In all regions of intellectual exertion — industry, science, art, literature, — there is a kind of ability displayed in taking up great and original ideas and combinations, before they have been made easy by iteration. Minds unable for the highest efforts of origination may yet be equal to this second degree of genius, wherein a considerable force of similarity is assisted by a small thread of contiguity. To master a large multitude of the discoveries of identification, a power of similarity short of the original force that gave birth to them, is aided by the contiguous bond that has grown up, during a certain number of repetitions of each. 10. A second case is, when a similarity is struck out in circumstances such as to bring the absent object into near proximity in some contiguous train. Thus, a poet falls upon a beautiful metaphor, while dwelling in the region where the material of the simile occurs. In the country, rural com- parisons are most easily made ; on board ship, nautical metaphors are naturally abundant. If we chance to be studying by turns two different sciences that throw much light on each other, we are in the best position for deriving the benefit of the comparison. When we know the most likely source of fertile similitudes for some difficult problem, we naturally keep near that source, in order that we may be struck with the faintest gleam of likeness, through the help of proximity. A historian of the ancient republics cultivates a familiarity with all the living instances of the republican system. Now that physical * ' On Tuesday, the 5th July (1763), I again visited Johnson. He told me he had now looked into the poems of a pretty voluminous writer, Mr. (now Dr.) John Ogilvie, one of the Presbyterian rainisters of Scotland, which had lately come out, but could find nothing in them. ' BoswELL. Is there not imagination in them, sir ? 'Johnson. Why, sir, there is in them, what xras imagination, but it is no more imagination in him,, than sound is sound in the echo. And his diction, too, is not his own. We have long ago seen ivJiite-robed innocence, Sundi fiower-besjjimgled meads' PEOXIMITY AS AN AID TO RECALL. 589 science is largely indebted to mathematical handling, the physicist has to maintain his freshness in mathematics. It is not altogether safe to trust to an acquisition of old date, however pertinacious the mind be in retaining the subject in question. The great discoveries of identification that astonish the world and open up new vistas of knowledge, have doubtless often been helped by the accidental proximity of the things made to flash together. For illustration's sake, we might suppose Newton in the act of meditating upon the planetary attraction, at the time that the celebrated apple fell to the ground before his eyes : a proximity so very close would powerfully aid in bringing on the stroke of identification.* Eeceucy of occurrence in the first instance has been already noted, as making revival easy, if not also spontaneous. It is a primary law of all impressions whatsoever, that, for some time after they are first made, they come back readily to the conscious- ness, even without an express associating link. More often still, they arise on a very slight touch of independent suggestion, such as might not have sufiiced if they had faded away into the dis- tance through lapse of time. All this is perpetually exemplified in the recollections involved in our everyday transactions (see Contiguity, p. 182). THE ELEMENT OF FEELING. 11. We have already seen, under Contiguity, that associa- tions grow up between objects and emotional states, whereby * Dr. Pick, a public lecturer ou Mnemonics, has suggested an aid to verbal memory, founded on mixed contiguity and similarity. If we are leai'ning a string of unconnected names, we must trust to contiguous growth solely ; but, if it be allowable to arrange them at pleasure. Dr. Pick suggests that we should find out an order, such that each word shall have in it something in common with the following, or some pre-established connexion of meaning. Thus, he takes the French irregular verbs, and arranges them in the following series (I give the English) : — sew, sit down, move, go, go away, send, follow, run, shun, etc. The previous connexion between the actions expressed by ' sew ' and ' sit down ' is obviously a powerful addition to the link of mere contiguity in utterance. Alphabetical arrangement (or Alliteration) gives a similar aid, although not so efficacious as the close alliance of meaning that occurs in the above series. 590 COMPOUND ASSOCIATION. the one can recall the other — the object reviving the emotion, and the emotion the object. Anything, for example, that has been strongly associated with a disgust, is apt to recall the feeling at a future time. This bond may be found entering into composite associa- tions. In remembering some past object that has been linked in the mind with a certain emotion, the presence of the emotion will contribute to the recall. Although not always sufficient of itself, this vinculum will often be found co- operating with others to effect the revival of an old recollec- tion. AYhile luxuriating in a state of agreeable warmth, we are easily reminded of former situations and circumstances when we were under the same feeling. ^Mlen we experience any of the special emotions — as Terror, Anger, Tenderness, Beauty, — objects connected with the emotion are attracted, while all others are repelled. In moods of tenderness, objects of affection rise by prefer- ence. If the mind is disposed to indulge in an irascible outburst, objects of anger and hatred find an easy opening, while others are shut out, although strongly suggested by separate links of association. Something occurs to bring to view a good deed performed by the obnoxious party ; but the suggestion is not entertained. "WTien an emotion possesses the mind in anything like fury, nothing that is discordant with it can find a place, while the feeblest link of connexion is sufficient to recall circumstances in harmony wdth the dominant state. 12. Hence, in minds very susceptible to eraotion, the more purely intellectual bonds of association are perpetually combined and modified by connexions with feeling. The entire current of thought and recollection is thus impressed with a character derived from emotion. AYhen tender affection is indulged as a dominant feeling, the objects that rise from the past, no less than those engaging the at- tention in the present, are for the most part tinged with this feeling. A joyous temperament has its genial recollec- tions ; melancholy opens the door to a totally different EMOTIONAL ASSOCIATIONS AID REPEODUCTION. 591 class. The egotist is eager for any suggestions that connect themselves with self, and a sHght contiguity or similarity will suffice to make these present. A strong natural feel- incf of reverence accumulates a store of ideas of things venerable, and gives them precedence in the resurrection of thought. This peculiarity has often arrested attention, and has been adopted as a theme both by poets and by philosophers. An intellectual and cultivated nature strives to maintain the ascendency of the intellectual associations over the suggestions of emotions. The dominion of reason is another expression for the same fact. When a particular emotion is excessive in the character, not only can we readily predict the actions, we can almost read the thoughts of the individual. The anecdote of Burke's divination of the thoughts of Goldsmith, when passing a crowd collected by the feats of a mountebank, can scarcely be called extravagant as an illustration in point. INFLUENCE OF VOLITION. 13. In many cases, our recollection of the past is pro- moted by Volition ; that is, we have some purpose or end in view which stimulates the activity of the system to bring about the recovery. I wish to recall the name of an object before me, to remember where I last saw a given person, to find a principle applicable to a case in hand. For a time, I fail in my endeavour; but, by prolonged effort, I effect the desired recovery. It is interesting to ascertain in what way the power of the will fuses with the intellectual forces of reproduction. At what point does this influence operate ? Can it augment a contiguous adhesiveness too feeble, or the attraction of a similarit}^ too little marked ? We must pronounce the influence indirect. There is, apparently, no power of adding to the energy of the associat- ing bond either of contiguity or of similarity, by a voluntary effort. The reproductions of the intellect are withdrawn 592 COMPOUND ASSOCIATION. from the control of volition. One thought cannot be made to succeed another, by mere will, as one movement of a limb may be made to succeed another. The modes of interference of a volition are as follows : — (1) In exciting the nervous system, so as to exalt the intensity of the mental processes generally. It is the nature of an end strongly felt, to stimulate and excite the whole frame of body and mind. Difficulty adds fuel to the flame. Under excitement, within bounds, everything we do is done with more vigour. The bodily efforts are stronger, the senses are more alive, the volitions are more intense, and the intellect shares in the stinmlation. (2) Volition may govern intellectual attention, in the same manner as observation in the actual. AVhen many things are before the eye, some are observed, and the rest passed by. A strong liking for one object of the scene stimulates the movements tl^at turn the gaze in that direction — as when an infant bends its eyes to the flame of a candle or to a familiar face. Now, I have already main- tained a lengthened argument to show that, in the recovery of objects as ideas, when they are no longer present as realities, the same nervous circles and the same organs of sense and movement are actuated, that were actuated in the original perception during the sensible presence. The ideal picture of a building is a series of impressions, sustained in the optic and the moving apparatus of the eye, and in the circles of the brain in operation at the time vhen we were gazing on the actual building. Wherefore, as we have the power to prolong our gaze at pleasure upon the real object, to turn from one part to another, to examine some points minutely and pass the rest over, — so, when this building becomes a recollection, the same power of varying the inward gaze remains to us. AVe can dwell upon the outline, to the exclusion of the details, we can concentrate the attention upon a column or a cornice, we can indulge our recollection of the appearance of the material; in a word, we can deal with the idea, notion, or OPERATION OF THE WILL IN MEMORY. 593 revived image, as we could with the reahty. Vohtion is not crippled by the transition from the actual to the ideal ; for the reason, as I conceive, that the same organs are concerned in both. If the things of observation, when exist- ing as ideas, were made to pass into a separate chamber of the mind, we should have a difficulty in comprehending how they could be reached by this voluntary control ; because I look upon volition as existing only in connexion with the active organs — that is, with the muscular system. Even in the sphere of thought, the limitation holds. The same voli- tion that rules the bodily eye, can rule the mental, because that mental eye is still not other than the bodily one. (For apparent anomalies and exceptions to this law, see The Emotions and the Will, p, 372.) Thus, then, volition operates in aiding the recovery of the past, through the power of directing and fixing the attention on any of the objects present to the mind at the time, to the exclusion of others. I remember one link of an otherwise forgotten chain : I dwell upon this link till it becomes more vivid itself, and thus acquires the power of calling up the rest. The object so selected is the one made intensely present, and thereby becomes the starting- point of the association. The idea that next comes up in the movement of reproduction, will be some associate, or similar, of this ; just as the thing that we select for special observation out of a various array seen by the eye, will be the thing that will suggest the next idea that rises before the mind. AVe can, therefore, always give a preference of attention to one of the many objects that come up to our recollection, whichever is thus preferred being rendered the suggestive object ; and, consequently, the resuscitated trains will be those in accordance with the purposes or ends of the moment. In difficult or laboured recollection, we have already seen that the chief hope lies in obtaining additional bonds of association. An effort of volition is the means employed. The effort consists in fastening the attention on various 38 594 COMPOUND ASSOCIATION. things within the view till these, one after another, are rendered suggestive of trains of ideas, some one of which perchance may have a connexion with the thing sought, and may supplement the deficient bond up to the full power of recall. In searching out a historic parallel, for example, we may suppose the power of similarity unequal to the task of evoking a proper instance. The mind then starts off in a train of contiguity over the field of history ; which proceeds, not by any voluntary power of commanding one fact to succeed another, but by directing the view on a starting- point — the age of Alexander the Great, for instance : with the attention fixed on him, the associated particulars of his time, so far as they have been made coherent, flow in of their own accord. This power of concentrating the attention on any part of a circle of notions present to the mind, like the power of directing the observation on some one aspect of a real scene, appears to be the main function of volition in the resuscitation of the past. A COMPLEX START NEEDED FOR A SINGLE TRAIN. Attention has already been called (page 481) to the frequent necessity of providing a complex situation as the associative antecedent in a given case of recovery of the past. This is readily confounded with plural associations in the sense of the present chapter, but is really a plurality of a distinct species : it is, indeed, of far more frequent occurrence in our intellectual resuscitations in the case now in hand. Its full elucidation is exceedingly various, as the following instances will show. 14. If I look at a mountain, there are many trains that I may be led into, by taking this as a point to start from. By simple contiguity, I may pass to the other mountains of the chain, to the plains and the villages beyond, to the mineral composition of the mass, to the botany, to the geological structure, to the historical events happening there. By similarity, I may be led away to mountains that I have seen in other lands, or in the representations of the painter and SPECIALIZING BONDS IN EQUALITY OF ATTRACTIONS. 595 the poet, to the analogous geometrical forms, to equivalent artistic effects. All these vents may be open to me ; but it will happen that I go on some one track by preference, and there will be a motive for the preference. Perhaps, one of the associations may have come by repetition to have greater force than any other : I may have been so accustomed to associate together the mountain and the neighbouring village, that I am led at once upon this one special transition. Another cause may be the presence of a second associating bond. If I see the adjoining mountain, I am then liable to be led along the chain : if I catch the glancings of the cascades, there is a double link of contiguity, tending to carry my mind to the river flowing from the sides of the mountain. If historical events have been recently in my mind, the events referable to this locality are suggested. If botany or geology is my study, a bent corresponding to these is impressed on the current of thought ; if geometry, the forms suggested by preference are the figures of geometry ; if I am an artist, the forms of art spring up instead. The position supposed almost demands an additional and a specializing bond to set the mind in motion at all. We could imagine an intellectual situation so equally balanced, that no revival took place in any direction, — just as in a conflict of equal volitions. Some inequality of restorative power in the various trains, or some second association coming in aid of one to give that one a preponderance, is the condition of our reviving anything. The case of an intellectual stand- still between opposing suggestions is neither chimerical nor unexampled. I will suppose another instance. A violent storm has flooded the rivers, blown down trees and buildings, and inspired general terror. The trains of thought suggested by such an incident are extremely various, and will depend on the mental condition of the observer in other respects, or on the special ideas that concur with the aspect common to all. The sailor's wife thinks of her husband at sea. The merchant and underwriter have their thoughts on the same element. 596 COMPOUND ASSOCIATION. The farmer calculates the loss to his fields. The millowner sees a prospect of abundant water power. The meteor- ologist studies the direction, duration, and force of the hurri- cane, and compares it with previous cases. The poet sees grand and imposing effects. The religious man has his mind carried upwards to the Deity. These instances imply some habitual attitude of the mind, or an emotion, occupation, or pursuit, ever ready as a starting- point to the intellectual movement, and combining itself with every casual impetus given to the mental trains, so as to constitute an element of the composite effect. The principle is exactly the same in cases where the second association is present merely by accident. 15. We have more than once adverted to the mental aggre- gates, formed by the cluster of properties attaching to natural objects, especially as viewed by the scientific mind. Thus, the idea of the mineral quartz is a vast assemblage of facts, properties, and influences, all which are liable to come before the view, when the mineral is seen or named. So, even a naked circle is rich in associations to the geometrical mind. It does not, therefore, follow that, every time a mineralogist looks upon a piece of quartz, all its many qualities shall rise and pass before his view ; or that every circle shall hurry the mind of a geometer all through the Third Book of Euclid. The associating links, in both cases, are good and sound ; but some motive additional to the force of the acquired adhesions is needed actually to recover any one train. Not only must the mind be disengaged from other trains, there must also be a positive stimulus, a second starting-point, to indivi- dualize and determine the bent of the suggesting power to one or other of the many associated ideas. If I am handling a piece of quartz and trying a knife edge upon it, the degree of hardness of the mineral is the quality suggested ; if an acid is at hand, the chemical action of quartz is brought up to the view ; and so on. When one of the many properties of the circle strung together in the mind of a mathematician is resuscitated by preference, it is by the agency of some FEWNESS OF IDEAS MAKES A MORE RAPID FLOW. 597 specializing notion pointing to that individual. The most opulent mind must have moments of quiescence ; and yet how numerous the possible outlets of thought at every moment ! OBSTRUCTIVE ASSOCIATIONS. 16. It will now be apparent that thoughts may fail to be suggested, notwithstanding an adequate force of association. We have had two remarkable cases in point : — the influence of an emotion in keeping back what is not in harmony with it ; and the necessity for an additional determining link where many lines of suggestion are equally open. These are not all. A recollection is sometimes made impossible, through the mind's being inextricably seized with something near what is sought, but yet different. We are often in this state of embarrassment in remembering names. Falling accidentally into a wrong articulation, we are unable to get out of the coil ; and it is not till sometime afterwards, that we are even in a position to give a fair trial to the recollective adhesion actually possessed. So, as we have seen, a stroke of similarity may be effectually resisted, by the presence of something repugnant. The principle of compound association necessarily involves this efficacy to obstruct. If two ideas, by both pointing to a third, con- stitute a prevailing bond of restoration, it must happen that, if these two present ideas point in opposite directions, they will be liable to neutralize one another's efficacy. The power of assisting implies the power of resisting. Both in the present chapter, and in speaking of con- structive associations in the following chapter, it is open to us to remark the distracting influence of too many ideas. Promptitude of action is greatly favoured by the fewness of the considerations that enter into a question. Marvels of ingenuity are often accomplished through the absence of superfluous suggestions. In the operations of animals, happy efforts occur to surprise us, as being apparently out of keeping with the range of their faculties ; in some in- 598 COMPOUND ASSOCIATION. stances, the explanation is found in the Hmitation of the views. The animal does not suffer from a crowd of incom- patible associations. The same circumstance often explains the extraordinarj' facility of speech, or the readiness in action, of men very deficient in mental force generally. It is ob- served by philologists that our cultivated languages have ceased to form new roots. The reason is, that the existing roots stand in the way. Originality is everywhere arrested by the presence of a large stock of already-formed concep- tions. Children, before learning the common-places, often give birth to original remarks. When there are many distracting portraits of the same individual, if we have been rendered most familiar with the inaccurate ones, it is very difficult if not impossible to abide by the most authentic when it comes within our reach. This is notably exemplified in the portraits of Queen Mary, and also in those of Shakespeare, after we have examined the bust at Stratford Church. As a contrasting illustration, we may refer to the remarkably consistent lineaments of the various portraits of Oliver Cromwell. 17. Obstructive association may be traced, on a grand scale, in the conflict of different modes of viewing the objects and occurrences of the world. There is a standing hostility between the Artistic and the Scientific modes of looking at things; and an opposition less marked between the Scientific, or the Theoretical, and the Practical points of view. The artistic mind is obstructed by the presence of considerations of scientific truth ; and the scientific mind, bent on being artistic, walks encumbered, and with diminished energy. Poetic fiction is never so brilliant as when the trammels of truth are set aside. A good instance of the obstructiveness of incompatible ideas is found in the effort of guessing riddles and conun- drums. These always turn upon the equivocal meanings of words. Now, a mind accustomed to dwell upon the real meanings of language is disqualified from following out the play of equivocation, not because the requisite associations CONTRAST A PHASE OF RELATIVITY. 599 do not exist, but because these are overborne by others inimical to the whole proceeding. The power of conjuring deals largely with the means of setting the spectators on some wrong tack. ASSOCIATION OF CONTRAST. 18. Aristotle's enumeration of the associating principles of the mind included Contrariety, along with Similarity and Coadjacency. Various subsequent writers have likewise viewed Contrast as a primitive suggesting force of our intel- lectual constitution. It is a well-known fact that objects do, on many occa- sions, bring before the mind their contraries. An intense light will suggest darkness or shade ; present sorrows will bring up past joys ; and a moment of brilliant prosperity may not be unfavourable to the recollection of times of adversity. Contrast is the reproductive phase of the first law of mind — relativifi/, or Discrimination. Everything known to us is known in connexion with something else, the opposite or negation of itself : light implies darkness ; heat supposes cold. Knowledge, like consciousness, in the last resort, is a transition from one state to another ; and both states are included in the act of knowing either. Nothing, then, can be more natural, when we are considering any one property, than the disposition to revert to the other property which makes its contrast or opposite — the thing denied when it is affirmed. ' Great ' would have no meaning to us, would never have been named or marked as a quality, if we had not had before us things of unequal magnitude, whose diifer- ence or contrast affected our minds with a lively impression. The ' great ' is great only because there is a something else ' not great,' or ' small ' : even when we imagine we are looking at the single property greatness, we have in our minds by implication the alternative, smallness ; and it is only like reversing the magnet, to pass to the explicit con- sideration of the alternative — in which case, the other, 'great- 600 COMPOUND ASSOCIATION. ness,' would be the implied property. This is what we do, when we pass from one member of a contrast to the other : both members must be in consciousness or within easyreach of consciousness, although we make only one the explicit object of consideration for the time. That the other member is still before us in a manner, is shown by the fact that, if we have been long absent from the express consideration of the alternative, we become oblivious to the force of the principal. The elfect of summer warmth continued for a length of time, is to diminish the sense of warmth ; a few wintry days interpolated would revive the poignancy of the sensation. When a meaning is but dimly perceived by any one, the fault most frequently lies in the non-recognition of the op- posite — that is, the thing to be excluded or denied, — the sup- pljdng of which renders the notion luminous at once. Show a child a rod, and tell him that it is straight ; you will pro- bably convey no notion whatever to his mind. But present, at the same time, a bent rod, and say that it is not straight, but bent, and j^ou impart a genuine cognition. Thus, then, whenever we have an object in our view, we have by impli- cation the opposite ; we can, on the smallest motive, reverse the couple, which is to pass to the contrast. Thinking of 'just,' with some definite meaning, we must have in the mind, only in a less prominent shape, the notion of some things that would be the reverse of just ; and, if we want to make the idea of the just more lively and definite still, we pass for a time to the explicit consideration of those ' not just ' things, and then return to the other. In Art, contrast is a standing ingredient, and hence is readily suggested. A scientific expounder is aware that, to add the ' antithesis ' or * counter-proposition ' is only completing the statement ac- cording to the fundamental law of cognition : hence, in him the ' association of contrast,' in the form of passing from the thing affirmed to the thing denied, is a settled habit. 19. But, further, it is to be observed that the other powers of the intellect — Betentiveness or Contiguity, and Similarity — concur in some degree with the primordial prin- CONTRAST SUPPOSES SIMILARITY. 601 ciple of Relation, in enabling us to pass from one thing to its contrast. Thus, as regards Contiguity, it happens that the greater number of contrasts are, in consequence of their necessary proximity from the nature of knowledge, habitually coupled in common speech ; whence, we acquire a tendency to pass from the one to the other "by mere rote, like completing a hackneyed form of words. Such associated couples as white and black, high and low, up and down, large and small, thick and thin, weak and strong, good and bad, 3'oung and old, rich and poor, life and death, pain and pleasure, true and false, — are in everybody's memory ; if one member is presented, the other is instantly ready to come up. Carlyle, concluding his life of Friedrich, uses the expression ' good reader, adieu ' : the habitual coupling of good and bad operating in his mind leads to the suggestion, which he adopts from its comic effect, ' bad also, adieu '. Among our acquisitions of Contiguity, these contrasting pairs are very numerous. This fact alone would suffice to render contrasting qualities frequently suggestive of each other. Xext, as to Similarity. It is an old maxim, that contraries imply community of kind. AVhere there is nothing common, there can be no opposition. "\Ve oppose a long road to a short road : we do not oppose a long road to a loud sound. We can contrast black with white, because they agree in kind— they are both colours and modes of light. Thus it is, that, when any quality is present to the mind, the opposite quality never can be far off, seeing that this is only another species of the same kind of object. When we see any one gaily attired, the subject of personal decoration is brought before the view, and one variety of it suggests, by virtue of the generic agreement, other varieties, among which there may occur cases of squalor or meanness. So, when we encounter a person suddenly deprived of means, the subject of human conditions is present to the mind, and, by Similarity, other instances may be brought up ; the mental condition of the moment operating as an adjunct to determine whether the 602 COMPOUND ASSOCIATION. same species or the opposite extreme will be suggested. Thus, a giant may suggest other giants by similarity, or a dwarf by contrast, according to the mood or the intellectual attitude of the moment. 20. We have, further, to note the emotions frequently aroused by contrasts. To take one class of examples. When any quality is present in a painful excess, the opposite quality is unavoid- ably suggested as a remedy to the evil. Darkness in this way causes a craving for light, and too much light impels us to seek the shade. So, cold and heat, hunger and repletion, exercise and rest, and many other things, operate in the same way. Again, there is a strong emotion of the poetic or artistic kind, generated by many contrasts. We are moved by seeing infancy and age placed together ; the still greater contrast of life and death has a solemnizing influence. In the fortunes of men and nations, we are struck with the conjunction of the high and the low, with the greatness that has emerged from obscurity, and the pride that goeth before destruction. This effect has been worked up in the poetic literature of nations. Among the Greeks, the idea of nemesis was an intense, ever- present conception ; even the accurate mind of Herodotus was superstitiously sensitive on this point. In no age has either the poet or the moralist allowed the reverses of human conditions to drop out of the view of the multitude. All the contrasts of this class are, therefore, disposed to be mutually suggestive to a very high degree. Another striking example of the influence of emotion in determining the rise of thoughts, is furnished by the well- known feeling called the love of contradiction. The clear expositor of truth knows that contrast is a means of illus- tration, and is moved, on that ground, to pass from any given idea or proposition to the opposite ; while the contentious disposition produces the same tendency to search out the contradictory of every aflirmation that happens to be brought forward. CONTRAST CLEARS THE MIND OF CONTRADICTIONS. 60.H 21. A better use of the reproductive power of contrast, is to impel us to unity and consistency in our opinions or beliefs. If we hear anything stated at variance with some- thing formerly known or believed, we are likely to be reminded of the previous statement. If I have ever affirmed, or heard any one aftirm, that the Homeric poems were the work of one man, and if now I am asked to believe that these poems were composed by several authors, I cannot help being reminded of the opposite view. In this way, the past and the present are confronted as effectually as if the opposites had been affirmed at the same moment, and we are thereupon urged, by the whole force of revulsion against inconsistency, inherent in our nature, to dismiss one or other of the conflicting opinions. The power of Similarity, under the guise of Contrast, is thus able to rid the mind of contradictions, in so far as this can be done by bringing the conflicting opinions face to face. A present assertion revives any past assertion that may have been made on the same subject ; and, if the predicates con- tradict each other, an opportunity is given for choosing be- tween the two. It happens, however, in fact, that the same mind will at different times maintain irreconcilable proposi- tions unawares. Either the power of reinstatement by similarity is too feeble, or there is some strong feeling operat- ing that repels the approach of any fact not in accordance with the view held for the time being. Both causes are found at work. In an average intellect, the power of simi- larity is not energetic enough to search the past for all the statements that may have been made upon any subject now in hand ; and many inconsistencies are too subtle for the detec- tion of an ordinary mind. When we add to this intellectual feebleness the power of emotion — the influence of the likings and dislikings, — we have a sufficient explanation of the pres- ence of contradiction in the same mind. It has been already observed, that a strong feeling will rebut all ideas incompatible with itself, however strongly they may be suggested by the forces of association. I can suppose the Apostle Peter to have 604 COMPOUND ASSOCIATION. been unconscious of contradicting himself within a few hours, when under excitement for his personal safety. The strong affirmations he had so lately made on the very same subject might not even have come into his mind. A current of violent emotion, besides overbearing hostile considerations that may be actually before the mind, can so obstruct, I might almost say paralyze, the workings of association, that such considerations, however near, shall not be allowed to come on the stage. This is one of the characteristic influ- ences of emotions. Intellect cannot perform its ordinary functions in the presence of strong feeling. The accordance or discordance of objects and recollected ideas with the present emotion, is so powerful that the purely intellectual links may have but a small share in the resuscitation. The tendency of intellect proper is to banish all contradictions from the mind — in other words, to arrive at consistency, the test of truth : the tendency of men's emotions of all kinds runs counter to this, and renders the spectacle of a thoroughly consistent human being no less rare than admirable. CHAPTEE IV. CONSTRUCTIVE ASSOCIATION. By means of Association, the mind has the power to form new combinations, or aggregates, different from any that have been presented to it in the course of experience. 1. rriHROUGHOUT the whole of the preceding exposition, J- we have had in view the hteral resuscitation, revival, or reinstatement of former actions, images, emotions, and trains of thought. No special reference has been made to the operations known by such names as Imagination, Crea- tion, Constructiveness, Origination, Inventiveness ; through whichi we are supposed to put together new forms, or to give birth to images, conceptions, pictures, and modes of working, such as we have never before had any experience of. Yet, the genius of the Painter, the Poet, the Musician, and the Inventor in the arts and sciences, evidently implies a process, of this nature. Under the head of Similarity, we have had to trace the workings of a power tending to originality and invention, as when — in virtue of the identifying of two things lying far apart in nature — whatever is known of the one is instantly transferred to the other, thereby constituting a new and instructive combination of ideas. Such was the case when Franklin's identification of electricity and thunder led to the application of the Leyden jar to explain a thunder- storm. The power of recalling like by like, in spite of remoteness, disguise, and false lures, enters, as we have seen, into a very large number of inventive efforts, both in the 606 CONSTRUCTIVE ASSOCIATION. sciences and in the arts. But we have now to deal with constructions of a higher order of complexity. There are discoveries that seem nothing short of absolute creations — as, for example, the whole science of Mathematics ; while, in the Fine Arts, a frieze of the Parthenon, a Gothic cathedral, a Paradise Lost, are very far beyond the highest stretches of the identifying faculty taken by itself. Nevertheless, the intellectual forces operating in those creations are no other than the associating forces already discussed. The new combinations grow out of elements already possessed by the mind, and brought to view according to the laws already laid down. MECHANICAL CONSTRUCTIVENESS. 2. In our mechanical education, complex and difficult actions are acquired by taking the simple acts separately. We learn part No. 1 by itself; then part No. 2, No. 3, and the rest : when each of these parts is attained, an effort of volition joins them together. Mechanical combinations are usually formed by succes- sive additions. A certain movement is mastered ; another is entered on by itself, and when mastered is added to the first. In military drill, in learning to manipulate, or to dance, each step is practised alone ; when two have been attained in separation, they can be performed together, merely by wilhng it. A third and fourth are added, in the same way. There is no new difficulty in grouping or combining the distinct operations. Any awkwardness in the united effort is mainly owing to the separate parts not being fully con- firmed. Our mechanical acquirements often demand the sup2ires- sion of one member of a complex action — a decomposition, as it were, of some of the primitive associated movements. In this case, a voluntary effort is directed upon the member whose movement is to be suppressed. In walking, there is .a natural tendency to swing the arms and the body along PERVADING CONDITIONS OF CONSTRUCTIYENESS. 607 with the lower limbs. By a volition, these extra movements may be arrested, and the primitive aggregate reduced to a more select aggregate. Learning to swim is a good example to show what re- mains to be done in mechanical combination, after the sepa- rate acts are fullv mastered. The beginner includes among previous acquisitions the vokintary control of the arms, and of the lower limbs. Perhaps, indeed, this control needs to be improved as respects the swimming movements : accord- ingly, the first thing is to practise the separate acts of throwing out the arms and the legs. The next thing is to bring them together, in the proper rhythm or combination. There being, however, a certain delicacy of adjustment, the learner does not succeed at the first attempt. A'arious tenta- tives are made; and at last, by chance, the rhythm is hit upon, and, being hit upon, is persisted in. The moment of a successful achievement, after struggles, is singularly favourable to the cohesive process, according to the law of awakened and concentrated attention ; and the happy com- bination is already cemented to such a degree that fewer tentatives are required on the second occasion. By two or three more repetitions, the fusion is complete. The use of the razor in shaving may be quoted as another example in point. In the full detail of Constructiveuess, we shall have to exemplify these three main conditions : — namely, (1) a pre- vious command of the elements entering into the combma- tion ; (2) a sense of the effect to be produced ; and (3) a voluntary process of trial and error continued until the desired effect is actually produced. \T:RBAL CONSTRUCTm:NESS. 3. The facility in passing from mere iteration into new combinations is, perhaps, most obvious in the use of lan- guage. Few successions of words of any length, uttered in everyday intercourse, are precisely identical with any succes- 608 CONSTRUCTIVE ASSOCIATION. sion formerly said or heard by the speaker. Yet, we find it easy to adapt the old to new purposes. In the early efforts of imitation, whereby words are first mastered, there is a constructive process. Tha child has learned to say ha and na, and when these separate sounds become very easy to the organs, a chance impulse makes them run together into ban. Here, as before, the ripeness of the preliminary acquirements separately is the first condi- tion of a successful union. After acquiring a certain number of words, and a few simple forms of sentences, new forms are produced. The child has learned to say ' give me,' and also the names of a number of persons and things, ' mamma,' ' pussy,' ' dolly ' ; and, having the wish to give something to one of these, finds no difficulty in displacing ' me ' from the formula, and admitting ' mamma,' 'pussy,' as the case may be. An effort of volition is implied. Two utterances are present to the mind : the articulate activity is awakened, and repeats these utterances perhaps in two or three ways ; one is hit upon, such as to satisfy the purpose of the moment, and, being hit upon, is retained and repeated. The effort of substitution, once or twice put in practice, becomes easy ; the mind knows, as it were, to carry on the current of words so far, then to stop, and to fall into a different current, so as thereby to produce a third different from either. It is a part of the voluntary command of our movements, to stop a sequence at any stage, and to com- mence another train from that point ; which is all that is necessary in the case supposed. Out of the two sentences, ' I am going out for the day,' 'I am coming home for the night,' a third sentence is constructed, ' I am going out for the night,' by no further effort of volition than this — namely, to arrest the current of articulation at a certain point in the first, to pass into the second, suspending vocal articulation till the word ' the ' is reached, then to tack on the remainder, ' night,' to the words already enounced from the other. The constructiveness, therefore, lies, not in any purely intellectual CONSTRUCTING NEW SENTENCES. 609 operation, but in the command that the volition has ob- tained over the movements, by virtue of which command these are suspended and commenced at pleasure, in the service of a particular end. The intellectual forces bring to mind the former acquisitions bearing on the situation ; and, if no one previous form is strictly applicable, the volition singles out part of one and part of another, and makes successive trials, if need be, until tlie want is satisfied. Throughout the whole wide-ranging operation of adapting old forms of words to new meanings, this is essentially the process pursued. When all the elements requisite for a new combination are at hand, a volition alone is needed to make the selection and adaptation suited to the end in view. When there is not a sufficiency of forms within reach of the present recollection, the processes of intellectual recovery must be plied to bring up others, until the desired combination is attained. A voluntary effort is quite equal to the task of cutting down and making up, choosing and rejecting, sorting and re-sorting : the feeling of the end to he served is the criterion to judge by, and when this is satisfied, the volition ceases, the stimulus being no longer present. In all difficult opera- tions for purposes or ends, the rule of ' trial and error ' is the grand and final resort. It would thus appear that the first condition of verbal combinations for the expression of meaning, is a sufficient abundance of already formed combinations to choose from ; in other words, the effect depends on the previous acquisitions, and on the associating forces whereby old forms are revived for the new occasion. If a complex meaning has to be ex- pressed, every part of this meaning will revive, by contiguity and similarity, some former idea of an identical or like nature, and the language therewith associated ; and, out of the mixed assemblage of foregone phrases, the volition must combine a whole into the requisite unity, by trial and error. The more abundant and choice the material supplied from the past by the forces of intellectual recovery, the better will be the 39 610 CONSTRUCTIVE ASSOCIATION. combination that it is possible for the mind to form by the selecting effort. 4. Let us next advert to some of the higher conditions that have to be attended to, in making verbal combinations. Be- sides conveying a meaning, certain grammatical forms have to be observed; likewise, there are rhetorical properties or rules of good taste ; a certain melody or cadence is sought to be imparted; and, in poetic composition, the other qualities have to be attained under the restrictions of metre and rhyme. As a matter of course, the more numerous the requirements, the more diiiicult it is to satisfy them all ; but the mode of pro- ceeding is not altered in any essential point. When there are four or five different conditions to satisfy, the range of choice must be so much the wider. It is not enough that I can com- bine one form of words sufficient to express a certain mean- ing ; I must be able from my verbal resources, recovered from the past, to construct several forms all equally good as regards meaning, so that I may be able to choose the one that satisfies the other conditions as well. In fact, the mind must possess, not one way of bringing out a certain effect, but a plurality of ways ; and, out of this plurality, we fix upon the form that yields some second effect also desired. If a third effect is wanted, there must be a power of altering the combination already made, without losing the previous effects ; and for this end, we must be able to command a choice of equivalent phrases, in the room of those that are discordant as regards the new end.* Thus it is that we must have a plurality of ways of expressing any given meaning, a plurality of forms of the same grammatical construction, a plurality of forms of the same rhetorical propriety, and a great variety of sequences observing the same cadence. Through such opulence of syno- * Southey's lines on the Fall of Lodorc are au instance to show that a word-artist is a person that can bring up for any occasion a large variety of names for the same thing. It is by means of this abundance of past and recoverable phraseology, that the elaborate constructions of high composition are at all possible. The number of words that pass across the mind in form- ing a single couplet may be a hundred times those actually made use of. COMPOSITION IN LANGUAGE. 611 iiyms, we, at last, light upon a combination that satisfies all the requirements of the case. The refusal to combine in any instance can be met only by bringing forward new varieties of phrase, — sometiines by the bond of meaning, at other times by the bond of grammar, of taste, or of cadence. The more richly stored the mind is on any one of those particulars — that is, the greater the number of words associated with meanings, with melodious cadences, and so forth — the more surely will that one condition be observed, whatever may become of the rest. If the tendency has been to lay up stores of ex- pressions adapted to the conveyance of meaning, there will be no difficulty in matching a new meaning, although there may be a difficulty in getting the language to comply with the other requisites. If, on the other hand, through a great susceptibility to cadence, and by the mind being very much versed in melodious forms of speech, these forms be ready to occur in great abundance on all occasions, the flow of speech will be sure to be musical, but there will be no security for the fulfilment of the remaining conditions ; and it may happen that both sense and grammar are neglected. In poetry, metre has to be satisfied after all other conditions have been provided for, leading often to the necessity of dropping or changing some words or phrases that the other requirements might desiderate. Still, out of the abundance of choice presented, a patient mind may seize upon forms that shall not be devoid of any of the other important at- tributes. Or, if the first suggestion of the wording of a sentence is governed by associations with meaning, it will be easy for such a mind to make substitutions and altera- tions to meet the rhetorical condition. One of our familiar examples of contiguous association is the utterance of a name on the presentation of the thing named. There are, besides, innumerable instances of a more complex effect : as when some object occurring to the view is not pro- vided with a simple recognized designation, but needs to be accom- modated with something not already in use, and requiring to be constructed for the occasion — for example, when we encounter a 612 CONSTRUCTIVE ASSOCIATION. shade of colour not provided with a term in the current voca- bulary of colours. This is merely a first step leading on to the higher combinations of language, by which a speaker pro- vides expression for more and more complicated objects and situations rising successively into his view. The transition from pure Similarity to Constructiveness is often seen in the similes of poetry. Examples are abundant in Paradise Lost, — as in the well-known passage on Sin and Death and the Vulture in the third book. FEELINGS OF MOVEMENT. 5. We next proceed to exemplify constructiveness among our feelings and ideas. Movement gives rise, as has been seen, to a variety of conscious states ; some emotional, as the states of exercise and repose, and others v^ith an almost exclusively intellectual character, as the feeling of pressure, space, and form. I shall here take a few examples of the second kind. Having acquired a discriminative sensibility correspond- ing to some one resistance or pressure, we are enabled to construct the feeling of another differing in degree. I pos- sess in my hand, after much practice, the engrained impres- sion, say, of a pound weight ; and I am commanded to con- struct, conceive, or imagine, the impression corresponding to three pounds. For this end, I must endeavour to fuse the two notions of one pound and of a triple, being formerly very familiar with both in their separation ; the notion of tripleness being derived from the experience of the fact in quantities of various kinds. By keeping the attention very much bent upon the two elements in question, I may succeed in conjuring up an impression compounded of both, and corresponding more or less to the actual feeling of a three-pound weight in my hand. We are not unfrequently called upon to make efforts im- plying this sort of adaptation. If I have been accustomed to jump a ditch three feet wide, I can easily increase the notion for an effort of five feet. So, in throwing objects to CONSTRUCTIVENESS IN THE FEELING OF ARCHITECTUEE. 613 hit a mark ; in which case, the constructiveness is first operated upon the pre-conceived idea of the action, before passing to the action itself. The same power of changing degree may be put forth in reference to size and form. Having acquired the arm-sensi- bihty to a sweep of one foot, we can construct a feehng corresponding to the sweep of two feet, or half a foot. We can also change a given area from one form to another. By fixing the mind upon the form of a circle, and the area of a square pane of glass, we can construct the conception of a round piece whose diameter is the side of the square. The demand for certain Architectural proportions in buildings supposes an effort of the constructive faculty, applied to the muscular feelings of weight and resistance. By moving and lifting pieces of stone of small size, we acquire a certain estimate of the inertia and gravity of the material ; an estimate that we extend constructively to large blocks, w^hich we cannot directly manipulate. By multiplying known feelings of muscular expenditure, we conceive, perhaps inadequately, the weight of a solid stone lintel ; and by similarly multiplying our experiences, on the small scale, of the tenacity of stone, wood, or iron, to resist pressure, we pronounce upon the sufficiency of two props of stone, of wood, or of iron to sustain that lintel. Such is our feeling of Architectural fitness, or of the sufficient in support. The emotional feelings of movement present a some- what different case. Under the two next heads, I shall adduce examples of emotional constructiveness in general. CONSTRUCTIVENESS IN THE SENSATIONS. 6. Beginning with Organic sensibility, we might cite instances of constructiveness, in the endeavour to conceive pains or hurts of a different kind from any we have experi- enced. We can, as usual, make the change of degree ; and, if the new state is either a combination, or a disjunction, of 614 CONSTRUCTIVE ASSOCIATION. two already familiar to us, we may hope to succeed in evoking it. The agreeable and joyous states of organic sensibility are very various. Each one of us has experience of some of them ; and, starting from these, we may be made to conceive others, if the description — that is, the method of compound- ing the known into the known — be clearly given. I may never have experienced the ecstasy of intoxication by opium ; but, if I have felt a number of states whose combination would amount to this effect, and if these are pointed out to me, I may, by an effort, recall and fuse them into one whole, so as to construct the feeling in question. This is by no means an easy undertaking to the generality of people ; and the reason is, that the strong organic feelings are not readily recoverable at all times in their entire fulness. Some one leading element of the combination sought would require to be present in the reality ; and then it might be possible to bring up others, and to form a new conception, by introduc- ing the requisite modifications. But, on the other hand, this method has disadvantages : it is not easy to modify a strong and present reality by mere ideas ; it would be more practic- able to modify a mere recollection, which is itself ideal. The non-intellectual nature of the organic feelings, rendering them stubborn to recall, however powerful they be in the actual, is the great obstacle to our easily conceiving non-experienced varieties of them. A person may have enjoyed the pleasures of eating, in a sufficient number of forms to possess all the elements necessary for conceiving the most luxurious feast that ever man sat down to ; yet, it might not be possible to attain to the conception. The difficulty of forming new com- binations, in some one region of sensations, is only another form of the difficulty of retaining and recovering our own experiences in that region. If I cannot easily conceive a degree, or kind of hunger, beyond anything I have ever known, it is because the states of hunger that I have actu- ally experienced cannot be well restored after they have completely passed away. CONCEIVING OF INEXPERIENCED TASTES. 615 Inasmuch as Tastes, properly so called, are somewhat more intellectual than organic states, we can do more in the way of forming new combinations of them. Given a bitter, such as bitter aloes, and a saline taste, as of common salts, we might construct a taste combined of the two. So, a sweet and an astringent might be fused. We might thus attain to the conception of tastes not actually experienced. The effort would doubtless be laborious in most instances, chiefly owing to the imperfect recollection that we have of tastes, even after much repetition. A person specially educated in tasting would have so much the less difficulty. And, if we wished to retain and revive the new conception, and to make it a possession of the mind, as much so as the taste of sugar, we should need an amount of repetition sufficient for the ideal coherence of the elements brought together. 7. Without dwelling upon the almost parallel case of smells, I shall pass to the first of the intellectual senses. Touch, including the muscular feelings associated with the proper tactile sensibilities, furnishes a more abiding species of recollections than the sensations just noticed, and we may, therefore, look for a higher degree of combining power among the feelings characteristic of this sense. I can acquire the touch of an orange, — that is, the bulk, the weight, and the softness of the surface. I have acquired also the touch of a marble table, and the weight of marble as compared with other substances. By a voluntary exertion of the mind, directing the view on the round figure of the orange, and on the touch and specific gravity of the marble, I might make to emerge a new perception — the collective impression of a marble ball equal in size to the orange. Part of the diffi- culty, in this trial, consists in the disassociatijiy or separating of elements that have grown together in the mind — an exercise commonly spoken of as an effort of abstraction, or analysis, and arduous, on the one hand, according to the strong hold that the property to be disassociated has taken of the mind, and, on the other hand, according to the weak hold that we have of the property to be substituted. If I 616 CONSTEUCTIVE ASSOCIATION. were very strongly affected by the peculiar soft touch of the orange, and had very little interest in the cold hard contact of the marble, there would be a repugnance in my mind to the proposed transmutation ; and the effort of abstractive or analytic volition, preparatory to the new combination, would be severe. A mind sensitive to the warm and sensuous elements of touch and colour, revolts from the operation, so familiar to the mathematician, of stripping these off, leaving only naked forms and arbitrary symbols to engage the intellect. The double decompositions, illus- trated by the above example, are made laborious by every circumstance that favours in the mind a preference for the combinations already existing, and correspondingly easy, when there is a partiality for the new combination that is to be the result. Thus, even when we operate upon subjects very conceivable and retainable, unlike the organic sensa- tions lately noticed, new difficulties may arise to clog the constructive operation. The mere effort of analysis is itself something considerable : it is not a favourite avocation of the untutored mind, with which associative growth is more congenial than disassociating surgery ; and, when the analysis has to be applied to break up favourite combina- tions, and constitute others of an unattractive kind, we become aware of the tyrannical influence that the likings and dislikings, the sympathies and antipathies, exert over the intellectual processes. The very great difference between the constructions of Imagination and the combinations for Practice or for Science is herein faintly shadowed forth. In the definition, or description, of the tactile quality of surfaces — woods, cloths, minerals, metals, — reference must be made to touches familiar to us, by whose combination we are supposed to attain the feeling of a surface not experi- enced. Touch is one of the defining properties of minerals. 8. In the very various states of mind excited through the sense of Hearing, there is wide scope for new combinations and constructions ; the mode of operating being much the HEARING. — SIGHT. 617 same as in the preceding instances. We may hear a note, or an air, sounded by an instrmnent or voice, and may wish to imagine it as a different instrument or voice. According as we have a good mental grasp of the air, and of the tones of the second instrument, the less effort would be needed for this transference. We have heard a piece performed on a fine band ; and we desire to conceive the effect of some other piece performed on the same band. Some faint approach to such a combination might be attained, but the exercise is not one that is much attempted. Few people engage in an occupation of this nature, or endeavour to create to them- selves non-experienced impressions with an approach to the vividness of reality. ' Imagine Macready, or Kachel, delivering that passage. We have heard the passage, and we have heard Macready. A constructive effort, taking place upon firm recollections of the two things to be combined, might be successful in such an instance. A good imitator, or mimic, actually succeeds in modifying his recollections of his original to suit an entirely new discourse. The ability to make the combina- tion, as in all other cases, rests in the first instance on the full possession of the separate elements. 9. Under Sight, the sense of easy conception by pre- eminence, the examples of cunstructiveness are necessarily copious. Light and shade, colour, lustre, visible size or dimensions, shape, distance, position, — are the constituents that unite in the complex perceptions of sight ; and it is possible to vary any given combination, by putting out and taking in elements at pleasure. I see or remember a line of houses ; I can imagine it prolonged to double or triple the length ; or I can transform the whole line by the addition of a story to the height. In the landscape, I see a mountain and a wood standing apart ; I place the wood upon the mountain. Or to take Hobbes's example of constructiveness :* I have * ' As when the water, or any liquid thing moved at once by divers move- ments, receiveth one motion compounded of them all ; so also the brain, or spirit therein, having been stirred by divers objects, composeth an imagination 618 CONSTRUCTIVE ASSOCIATION. the idea of a mountain and the idea of gold, and by super- imposing the one upon the other, I can evoke the image of a mountain of gold. Another example given by him is the joining of a man and a horse to make the Centaur. The facility in all such cases depends, as usual, on the perfect and easy command the mind has of the separate ideas, owing to their good ideal persistence. The combination takes place of its own accord, if the elements are once properly brought together and kept, as it were, in close contact for a sufficient time. A continuance of the effort will enable us to retain the new image, until the parts of it acquire a certain contiguous adhesiveness ; after which we shall possess it as a mental re- collection not differing essentially from the recollections of things actually seen. As in former examples, the decom- position and recomposition, implied m the constructive effort, may be aided or thwarted by emotions. Hobbes's mountain of gold would emerge the more readily that the image is one to excite men's feelings ; being an example of imagination in the more limited sense of the word, or in that sense wherein lies the contrast between it and the creations of the intellect for scientific or practical ends. If I see a dress, and want to conceive it of some other colour, I can most easily substitute either the colour that I am most familiar with, or the one that I have a special affection for. The re-disposing of the parts of an interior, or a scene, severely tests the constructive faculty. Wishing to re- arrange the furniture of a room, I endeavour to conceive beforehand the effect of a proposed arrangement. So, with a garden : a person must have a good retentiveness of the ideas of the parts, in order to put together, and hold firmly, of divers conceptions that appeareth single to the sense. As for example, the sense showeth at one time the figure of a moimtain, and at another time the colour of gold ; but the imagination afterwards hath them both at once in a golden mountain. From the same cause it is, there appear unto us castles in the air, chimeras, and other monsters which are not in rcrum natura, but have been conceived by the sense in pieces at several times. And this composition is that which we commonly call fiction of the mind ' {Human Nature, chap, iii., § 4). FORECASTING A NEW ARRANGEMENT OF THINGS. 61^ the new plan, so as to judge of the effect of it before taking any measures to realize it. An intellect naturally pictorial — that is, disposed to retain visual images in general, — and an education in the particular subject operated upon, are the requisites for success in such an operation. The suscepti- bility to beauty, or to the emotional effects of the several combinations, operates in favour of every construction that yields the emotion. CONSTRUCTION OF NEW EMOTIONS. 10. We may revive emotional states by contiguity or by similarity, or by a composition of associating bonds ; and, from two or more states thus revived, new emotions may be generated by constructiveness. I have already touched upon this, in speaking of the organic sensations ; these being almost purely emotional in their character. But, if we pass to the feelings that are more recoverable and more retain- able in the ideal form, we shall obtain examples of greater frequency in actual occurrence. The problem is to realize emotions such as we have never experienced in ourselves, or have experienced too rarely to recall them by any effort of mere recollection. The feelings belonging to men whose character, position, occupation, etc., are totally different from our own, can in general be conceived only through a constructive process, operating upon feelings that we do possess. There are certain elementary emotions that belong to human nature in general, although manifested very unequally, partly in consequence of primitive differences of character, and partly of variety in the outward circumstances of individuals. Every one has experience of wonder, of fear, of love, of power, of anger, of self-conceit, of remorse. Should any one of the elementary feelings be absent from a character, no constructive process is sufficient to create it : what constructiveness can produce is, by that very fact, not elementary. If, for example, a person were naturally devoid 620 CONSTEUCTIVE ASSOCIATION. of the emotion of fear, this emotion could not be generated by any known effort of construction. In like manner, the irascible feeling seems so distinct and peculiar that we could not be made to conceive it without direct experience. Even when an emotion not entirely wanting is yet allowed to sleep, the difficulty of rousing it may prove insuperable. Thus it is that some men are unable to enter into the senti- ment of reUgious veneration, and others are disqualified from comprehending the pleasures of the fine arts ; one class are utterly incapable of sympathizing with the pursuit of scientific truth, and another can never be made to under- stand the feeling of disinterested usefulness. The emotions that can be acquired by constructiveness are, therefore, the compound emotions, or some conceivable varieties of the elementary. We must be able in each case to specify certain primary feelings possessed by the person appealed to, the combination of which, in a particular way, shall yield the emotion that we desire to communicate or evoke. If the constituent elements are actually made pre- sent to the mind in their proper degree, the fusion will take place as a matter of course. Perhaps, the best commencing exercise in this art of conceiving other men's feelings would be to change the degree of one of our own emotions. I have a certain disposition to take on fear. It being, however, apparent that another person, whose character I am desirous of realizing, is susceptible to a much greater extent, I must endeavour to assume, for a time, a pitch of terror much beyond my own. This can be done in various ways. I may go back upon times of my life when the emotion took a greater hold of me ; I may conceive occasions and circum- stances of a kind to produce a more than ordinary degree of the state ; or I may revert to the particular subject that most easily depresses my courage. Or, again, instead of working upon the emotion itself, I may exert my imagination to construct objects of intense and overpowering terror, from the contemplation of which a high pitch of the feeling would arise. By these means I can be made to assume an combixinct two emotions into a third. 621 unwonted amount of the feeling, and can approach to the state of mind of the person supposed, so as to foreshadow^ the actions flowing from that particular state. By such endeavours, one might acquire an exalted cast of any familiar emotion. The exercise would cost both effort and time ; but, if we are able to revive with ease the past states of our own experience that bear on the case, we shall not be long in accomplishing the end in view. To acquire a new degree of intensity of any emotion so thoroughly as to be able to follow out all the influences and consequences of the feeling, is a very high effort, and demands iteration and time ; inasmuch as there is implied in it the process of fixing, into a permanent possession, a state of mind that has been worked up with labour. Thus, for the man that is only alive in a moderate degree to the pleasure of music, to be able, at any time, to rise to the state of an enthusiast, so as to depict that character in all its phases, there would be required a somewhat laborious practice. AVriters whose province it is to trace out and depict all the windings of characters dift'erent from their own, must work themselves into a number of unexperienced degrees and modes of feel- ing as a preparation for their task. 11. The exercise of combining two emotions, so as to bring out a third different from either, is not intrinsically arduous. Everything depends upon the facility of assuming the elementary feelings. If a person has ever known an affection of the nature of a passion for any one object, such a one is capable of conceiving, by an effort of transference, a passion for an object very different. Thus it is that Michelet, in endeavouring to pourtray the attachment of the French peasant proprietor for his land, brings into the picture the feelings of strong personal attachment. The difference of subject is great ; but the attempt is not, there- fore, hopeless. It would doubtless be much easier to transfer the feelings of love, in one personal relation, to some other relation, by making allowance for the difference, as in pass- ing from friendship to marriage, or to the parental relation. 622 CONSTRUCTIVE ASSOCIATION. The historian, who has to deal with extinct modes of feehng, and who has to study truth in his dehneations, is necessarily much versed in the exercise now under discussion. Grote forewarns his reader ' that there will occur nume- rous circumstances in the after political life of the Greeks which he will not comprehend unless he be initiated into the course of their legendary associations. He will not under- stand the frantic terror of the Athenian public during the Peloponnesian war, on the occasion of the mutilation of the statues called Hermse, unless he enters into the way in which they connected their stability and security with the domici- liation of the gods in the soil ' {Hist, of Greece, Preface). CONCRETING THE ABSTRACT. 12. Under a former head, I have supposed the case of fusing the properties of two different objects so as to make a third different from either. Given a brick building and a marble surface, to conceive a marble building. This is, to form a new concrete out of two pre-existing concretes. But we may go a step farther. Given the abstract properties, to construct the concrete whole. Take, for example, the geometrical form of a pyramid and the colour of granite, a,nd conceive the actual object as existing in nature. This is, in most cases, a somewhat more difficult operation than the foregoing, but can hardly be said to involve any new or distinct effort. If we realize the constituent elements with sufficient vigour, and keep the two together in the mind, the construction is sure to follow. If we have but a feeble hold of one or other of the parts, some exertion will be requisite to make them fall into their places in the new compound. When the plan and sections of a building are given, we have the means of realizing the form of the solid building ; when we add the colour of the surface, or the appearance of the material to the eye, the concrete emerges in all its fulness. In this case, the plan and sections would not be enough to give the full solidity, unless we had previously seen sohd CONCEIVING A BUILDING. 623 shapes. We require to fasten upon some remembered build- ing or form of building, and to alter this in the mind, till we bring out a correspondence between it and the plan supposed. Thus, in order to realize a Gothic church from a builder's designs, the easiest way would be to direct the view upon some church already familiar to us, and, on that, to make the alteration prescribed by those designs. This is a general maxim in concrete realization ; and by it we can easily under- stand the conditions that render the operation easy. It is evident that a previous store of well fixed objects of the par- ticular kind in question, is the great requisite. If the past experience of the indi\adual has given great opportunities for laying in such a store, and if the mind is naturally of a pic- torial and concrete order, the process of new construction has every advantage in its favour. Not to speak of the chance of possessing firm and recoverable ideas of objects approaching very near the new construction, there is a great facility in making the required alterations, if the thing operated on is vividly and easily held in the view ; provided always, that there is no serious obstruction from the feelings. To imagine a country from a map, is a case of the same nature. The effort consists in holding before the mind's eye a series of scenic views, in all the richness of the colouring, and all the fulness of the details, while performing the opera- tion of cutting out and taking in, so as to suit the prescribed outlines. An intellect rich in concrete or living conceptions of actual nature possesses the prime requisite for such a task. The mode of describing the objects of natural history is to enumerate the abstract properties. Thus, a mineral is described by such abstractions as crystalline form, hardness, nature of surface, colour, lustre, etc. Now, by a vigorous effort of constructive conception, one might realize an actual specimen from the assemblage of abstract qualities. So, with a plant or animal. The first condition of success is still the same. The mind must be well versed in actual specimens, so as to be able to lay hold of some concrete recollection, by operating upon which, a new specimen will emerge possessing 624 CONSTRUCTIVE ASSOCIATION. all the properties of the description. A botanist can readily form to himself the picture of a new plant from the botanical description ; a person less familiar with plants would find the construction laborious, perhaps impossible. 13. The more we analyze or decompose concrete objects into the abstract qualities that make them up, the more difficult is it to remount to the concrete. Hence, the most arduous attempt of all is to make actual nature rise up out of scientific and technical language, — to conceive minerals from a book of mineralogy, and the parts of the human body from anatomical description. This is the repulsive or un- favourable side of science and of abstract reasoning. On the other hand, it is by the process of resolving natural aggregates into their ultimate abstractions, that we obtain the means of making new constructions widely differing from, and superior to anything that exists in our experience, by which many important ends in human life are furthered. New creations of science, and new devices of industry, result from this power of re-constituting the ultimate abstract elements of existing things. Even the artist will find his account in it, although it is not usual with him to carry abstraction so far as either the man of science, or the man of practice. Many great poetic conceptions are the embodiment of an abstract idea. Milton's personification of the spirit of evil may be quoted as an example. REALIZING REPRESENTATION OR DESCRIPTION. 14. What is to be said on this head is little else than an application of the remarks already made. When we are desired to conceive an object differing from any that we have ever known, we can do so only by constructing it out of qualities and particulars indicated in a representation or description. The machinery of representation for such an end is known to be very various ; including pictures, sculp- tures, models, diagrams, and, greatest of all, language. If we wish to conceive a living human face by means of a coloured THE ART OF DESCRIPTION. 625 portrait, we require an act of constructiveness to make up the difference between the painting and the reahty ; we must fuse or combine a hving face with the features of the portrait, till the one is completely adapted to the other. The dithculty lies in separating the suggestive part of the picture from the gross total of canvas and colour ; and the labour is greater according as the painter has .attempted to produce a work of art — that is, a pleasing combination of colour and forms. There is here that effort of analysis, which I have already alluded to, as the preliminary of many constructions, render- ing them often very hard to accomplish. The same remarks apply to sculpture. An unartistic model (or wax image) is the best medium for enabling the mind to rise to the living and actual reality. 15. Verbal description is the most universal mode of imparting to the mind new ideas and combinations ; and the hearer or reader must exercise constructiveness to realize the intended image. The one method of procedure open to the author of the description is to compose the unknown out of the known ; the hearer must then implement the process by the force of his own mind, bringing together the suggested particulars into a combined total, with the requisite inclusions and exclusions. Language is made the medium for indicat- ing the things that are to be brought together, in the forma- tion of the new compound. 16. With regard to the describing art in general, as applicable to all cases where a complex object or scene has to be represented to the view, the leading maxim is to combine a concrete or a type of the whole, with an enumera- tion of the parts. This is in accordance with what has just been laid down, respecting the best method of rising from abstract elements to a concrete embodiment. Some compre- hensive designation that may spread out the main features of the object is indispensable to the description ; and, within this, the details may be arranged in proper form and order. The following is a very simple instance from Milton, which seems as if it could not have been stated otherwise than he 40 626 CONSTRUCTIVE ASSOCIATION. has done ; but art shows itself in carrying into compHcated cases the method that appears self-evident in easy cases. The words in italics mark the comprehensive designation or type ; the rest of the description giving the details : — They plucked the seated hills, with all their load — Rocks, waters, woods — and by the shaggy tops Up-lifting, bore them in their hands.* The power of bodying forth or realizing what is described in language is one of the meanings of Conception, which is given by some writers in the list of intellectual faculties. The same power is also expressed by Imagination, although not amounting to what is implied under this faculty. * Carlyle's description of the town and neighbourhood of Dunbar, the scene of Cromwell's decisive victory over the Scotch, is rendered vivid and conceivable, in consequence of his always prefacing particulars and details by terms and epithets that are at once comprehensive and picturesque : — ' The small town of Dunbar stands high and windy, looking down over its herring boats, over its grim old castle, now much honeycombed, on one of those projecting rock-protnontorics with which that shore of the Firth of Forth is niched and Vandyked as far as the eye can reach. A beautiful sea ; good land too, now that the plougher understands his trade ; a grim niched harrier of v)hinstonc sheltering it from thechafings and tumblings of the big blue German Ocean. Seawards, St. Abb's Head, of whinstone, bounds your horizon to the east, not very far off ; west, close by, is the deep bay, and fishy little village of Belhaven ; the gloomy Bass and other rock-islets, and farther, the hills of Fife, and forcshadoivs of the Highlands, are visible as you look seaward. From the bottom of Belhaven Bay to that of the next sea- bight St. Abb's-ward, the town and its environs form a peninsula. Along the base of which x^eninsula, " not much above a mile and a half from sea to sea," Oliver Cromwell's army, on Monday, 2nd of September, 1650, stands ranked, with its tents and town behind it, in very forlorn circumstances. ' Landward, as you look from the town of Dunbar, there rises, some short mile off, a dusky continent of barren heath hills; the Lammermoor, where only mountain sheep can be at home. The crossing of which by any of its boggy passes and brawling stream-courses, no army, hardly a solitary Scotch packman, could attempt in such weather. To the edge of these Lammermoor heights David Leslie has betaken himself ; lies now along the utmost spur of them, a long hill of considerable height. There lies he since Sunday night, on the top and slope of this Doon Hill, with the impassable heath continents behind him ; embraces, as with outspread tiger-claws, the base line of Oliver's Dunbar.' INTELLECTUAL FACULTIES OF THE CONCRETE. 627 There are three different intellectual operations, all based upon our sense-perceptions — Memory, or the literal repro- duction of something experienced ; Conception, or the pic- turing of what is described, by means of a constructive operation ; and Imagination proper, which implies the con- struction of something neither experienced nor presented to us in description by others. Although these operations progressively increase in difficulty, yet there is a common aptitude at the bottom. He that has the most vivid pictorial Memory, will have a corresponding facility in Conception, and in the still higher power of Imagination. CONSTRUCTIVENESS IN SCIENCE. 17. The Abstractions, Inductions, Deductions, and Expe- rimental processes of science, which we have already seen to be mainly dependent upon the workings of the law of Similarity, afford likewise examples of Construction. The first in order of the Scientific processes is Abstrac- tion, or the generalizing of a single attribute, so as to present it to the mind, apart from the other properties that usually go along with it in Nature. Thus, a square in Euclid is an abstraction : in nature, squareness is always accompanied with other properties, making the concrete, or actual, square, — a square pane of glass, a square of houses, etc. We have already seen that the forming of these abstract ideas is a result of the identifying action expressed by the law of Similarity (see Similarity, § 34). We have now to point out the cases where a considerable constructive effort is required, in addition to the force of identification. There are abstractions of a peculiar order of subtlety, which cannot be arrived at, or embraced by the mind, except through a constructive operation, adapted to the case by much study of the particular instances. Take, for example, the abstract idea of a gas. Here, the material eludes the senses, and cannot be represented by either an example or an outline, — like a mountain, or a circle, or a genus of plants. 628 CONSTRUCTIVE ASSOCIATION. And, if the iiidividLial gases are so difficult to represent, there must be a similar difficulty in attaining an idea of the property common to them all as a class. A case of this nature must be circumvented. AYhen we have ascertained by experiment the properties of one gas, such as the air, we record them in the best language we can obtain, by com- parison with the more palpable phenomena of solids and fluids. AVe find that the air is inert, and has weight ; that it is elastic, like a spring ; but that it is extremely light. Trying other gases, we find similar properties to hold good. AAHien, however, we experiment on the visible vapour of water, we find an absence of the elastic property belonging to air and invisible steam : in fact, this substance has nothing in common with aeriform bodies, but lightness or tenuity ; and, in the exercise of our discretion, we think it right to exclude it from the group, and embrace together only those that have the property of elasticity, or spon- taneous expansion, constituting this the defining mark, or the abstract idea of the class. By a similar process of groping, experiment, and the exercise of judgment, the scientific world has attained to abstract conceptions of the subtle properties expressed by Heat, Electricity, Chemical affinity. Cell-reproduction, etc. The definitions of these attributes are constructions labori- ously worked out. Nevertheless, the means of effecting them, so far as intellect is concerned, is still by the ordinary forces of association, which bring up to the view various facts, ex- pressions, and comparisons, in order to make tentative com- binations ; and these are gradually improved upon, as their unsuitability to the particular phenomena is discovered on examination. An intellect well versed in the kind of con- ceptions necessary, and acting vigorously in the reviving of these by association, is naturally qualified for the work. Next to this, is the second leading condition of constructiveness in general — a clear perception of the subject to be seized, or of the particulars to be suited. Possessing thus the material of the construction and a ABSTRACTION. — INDUCTION. 629 clear sense of the fitness or unfitness of each new tentative, the operator proceeds to ply the third requisite of construc- tiveness — trial and error — or, as Newton termed it, ' patient thought,' to attain the desired result. This power of patient thought may repose upon a strong bent of mind towards the subject in hand, a passion or fascination for the peculiar class of ideas concerned, such that these ideas can be detained and dwelt upon without costing effort. The mathematical mind, in addition to its intellectual aptitude for retaining and recovering mathematical forms, should have this con- genial liking for these forms, in order to prepare it for original discovery. The number of trials necessary to arrive at a new construction is usually so great that, without something of an affection, or fascination, for the subject, one grows weary of the task. The patient thought of the naturalist, desirous of making new classifications, grows out of his liking for the subject, which makes it to him a sweet morsel rolled under the tongue, and gives an enjoyment even to fruitless endeavours. This is the emotional condition of originality of mind in any department. When Napoleon described himself as ' nn homme j^olitique,' we are to interpret the expression as implying a man of the political fibre or grain, a character whose charm of existence was the handling of political com- binations, so that his mind could dwell with ease in this region of ideas. 18. What has been said above, with reference to the Abstractive process of science, applies also to Induction — the generalizing of pro2Jositio7is, or truths. This may be a simple effort of the reproductive force of similarity ; or there may be wanted a constructive process in addition. In gene- ralizing the law of the bending of light in passing from one medium to another, Snell constructed a proposition by bring- ing in a foreign element — namely, the geometrical sines of the angles : he found that the degree of bending was as the sine of the inclination of the ray. This is a good example of the devices required to attain to a general law. A mind well versed in such foreign elements, apt to revive them, and 630 CONSTRUCTIVE ASSOCIATION. disposed to dwell upon them, will be the most likely to suc- ceed in the happy fetches and combinations that clench great principles of science. 19. In the processes of Deduction, by which general laws and principles are applied to the clearing up of particular cases, and to the solving of problems, the same constructive process has often to be introduced. The mind being prepared beforehand with the principles most likely for the purpose, and having a vigorous power of similarity in that region, incubates in patient thought over the problem, trying and rejecting, until at last the proper elements come together in the view, and fall into their places in a fitting combination. The vast structure of the mathematical sciences is a striking example of constructiveness, as distinguished from the discoveries of mere identification through the law of similarity. In Geometry, in Algebra, in the higher Calculus, and in the endless devices of refined analysis, we see an apparatus perfectly unprecedented, the result of a long series of artificial constructions for the working out of particular ends. It would not be difficult to trace out the course of this creative energy ; the mental forces involved in it being no other than those that we have dwelt upon. 20. In the devices of Experimental science, there comes into play a constructiveness akin to invention in the arts and manufactures. The air-pump, for example, is an illustrious piece of constructive ingenuity. The machine already in use for pumping water had to be changed and adapted to suit the case of air ; and it was necessary that some one well versed in mechanical expedients, and able to recall them on slight hints of contiguity, or similarity, should go through the tedious course of trials that such a case required. Putting together the applications of the Retentive power of the mind in Science (Contiguity, § 70), the explanation of the operations of Abstraction, Induction, and Deduction (Similarity, § 34), and what has now been said as to the nature of the Constructive operation, we have an account, as complete as I am able to give, of the composition of the THE ACTIVE TURN IN PRACTICAL INVENTION. 631 Reasoning faculty, viewed in its most comprehensive appli- cation. PRACTICAL CONSTRUCTIONS. 21. The region of inventions for the practical ends of life might be searched for illustrations of constructive genius. So, the department of administrative capacity in every class of affairs, and every kind of business, might be explored with the same view. Not one of the leading mental peculiarities already laid down as applicable to scientific constructiveness, can be dis- pensed with in the constructions of practice : — the intellectual store of ideas applicable to the special department ; the powerful action of the associating forces ; a very clear per- ception of the end, in other words, sound judgment ; and, lastly, that patient thought, which is properly an entranced devotion of the energies to the subject in hand, rendering application to it spontaneous, if not easy. With reference to originality in all departments, whether science, practice, or fine art, there is a point of character that deserves notice, as being more obviously of value in practical inventions and in the conduct of business and affairs, — I mean an Active turn, or a profuseness of energy, put forth in trials of all kinds on the chance of making lucky hits. In science, meditation and speculation can do much, but, in practice, a disposition to try experiments is of the greatest service. Nothing less than a fanaticism of experimentation could have given birth to some of our grandest practical combinations. The great discovery of Daguerre, for example, could not have been regularly worked out by any systematic and orderly research ; there was no way but to stumble on it, so unlikely and remote were the actions brought together in one consecu- tive process. The discovery is unaccountable, until we learn that the author had been devoting himself to experiments for improving the diorama, and thereby got deeply involved in trials and operations far removed from the beaten paths of inquiry. The energy that prompts to endless attempts was found in a surprising degree in Kepler. A similar untiring 632 CONSTEUCTIVE ASSOCIATION. energy — the union of an active temperament with intense fascination for his subject — appears in the character of Sir Wilham Herschel. When these two attributes are conjoined — when profuse active vigour operates on a field that has an unceasing charm for the mind, — we then see human nature surpassing itself. The invention of Daguerre* illustrates, by a modern instance, the probable method whereby some of the most ancient inventions were arrived at. The inventions of the scarlet dye, of glass, of soap, of gunpowder, could have come only by accident ; but the accident, in most of them, would probably fall into the hands of men engaged in numerous trials upon the materials involved. Intense application, — ' days of watching, nights of waking,' — went with ancient discoveries as well as with modern. In the historical in- stances, we know as much. The mental absorption of Archimedes is a proverb. \ A remark may be made here, applicable alike to Science and to Practice. Originality in either takes two forms, —Ob- servation or Experiment, on the one hand, and the identifying processes of Abstraction, Induction, and Deduction, on the other. In the first, the bodily activities and the senses are requisite ; the last are the purely intellectual forces. It is not by high intellectual force that a man discovers new countries, new" plants, new properties of objects ; it is by putting forth an unusual force of activity, adventure, inquisitorial and per- severing search. All this is necessary in order to obtain the observations and facts in the first instance ; when these are collected in sufficient number, a different aptitude is brought to bear. By identifying and assimilating the scattered * The wonderful part of this discovery consists in the succession of pro- cesses that had to concur in one operation, before any effect could arise. Having taken a silver plate, iodine is first used to coat the surface ; the surface is then exposed to the light, but the effect produced is not apparent till the plate has been immersed in the vapour of mercury. To fall upon such a combination, without any clue derived from previous knowledge, an innumerable series of fruitless trials must have been gone through. MEANING OF THE FACULTY OF JUDGMENT. 633 materials, general properties and general truths are obtained, and these may be pushed deductively into new applica- tions — in all which, a powerful reach of Similarity is a main requisite ; and this may be possessed by men totally destitute of the active qualities necessary for observation and experi- ment. The Romans were seemingly the first inventors of man}'- political institutions, which were adopted and extended in all civilized countries. The Source of their originality was simply trial and error in the situations that occurred in the course of their political experience. Dictator, Censor, Inter- regnum, Imperator, Consul, Pro-consul, and many other designations in law and in politics originated with them, as so many devices adopted at first hand. The power of Similarity in Diversity, operating upon these primary sug- gestions, made them available in new^ circumstances, unfore- seen by the men that had the credit of first devising them. 22. The present topic furnishes a good opportunity for singling out, for more special notice, the quality of mind known by the name of Judgment. I have already included a clear perception of the end to be served as essential to a high order of constructive ingenuity, simply because, without this, though there may be a great profusion of devices and suggestions bearing upon the required combination, the fitting result is really not arrived at. Some combination short of the exigencies of the case is acquiesced in. The various regions of practice differ much in respect of the explicitness of the signs of success. In some things, there is no doubt at all : we all know wiien we have made a good dinner, when our clothing is warm, or when a wound has healed. The miller knows when there is water enough for his mill, and the trader knows when he has found out a good market. The end in those cases is so clear and manifest, that no one is deluded into the notion of having compassed it, if such be not the fact. But, in more complex affairs, where perfect success is unattainable, there is room for doubts as to the degree actually arrived at. Thus, in public 634 CONSTEUCTIVE ASSOCIATION. administration, we look only for doing good in a considerable majority of instances; and it is often easy to take a minority for a majority. So, in acting upon human beings, — as in the arts of teaching, advising, directing, persuading, — we may suffer ourselves to fall into a very lax judgment of what we have actually achieved, and may thus rest satisfied with easy exertions and fiimsily-put-together advices. A sound judg- ment, meaning a clear and precise perception of what is really effected by the contrivances employed, is to be looked upon as the first requisite of the practical man. He may be meagre in intellectual resources, he may be slow in getting forward and putting together the appropriate devices, but, if his perception of the end is unfaltering and strong, he will do no mischief and practise no quackery. He may have to wait long in order to bring together the apposite machinery, but, when he has done so to the satisfaction of his own thorough judgment, the success w^ill be above dispute. Judgment is in general more important than fertility ; because a man, by consulting others and studying what has been already done, may usually obtain suggestions enough, but, if his judgment of the end is loose, the highest exuberance of intellect is only a snare. The adapting of one's views and plans to the opinions of others is an interesting case of constructiveness, and would illustrate all the difficulties that ever belong to the operation. A more abundant intellectual suggestiveness is requisite, according as the conditions of the combination are multiplied ; we must transform our plan into a new one containing the essentials of success, with the addition that it must conform to the plan of some other person. There is, in that case, a considerable amount of moral effort, as well as of intellectual adaptation ; the giving way to other men's views being by no means indifferent to our own feelings. The subject of Speech in general would present some aspects of the constructive mechanism not hitherto dwelt upon in our exposition. A fluent speaker constructing verbal combinations adapted to all the exigencies of meaning, IMAGINATION ESSENTIALLY INVOLVES EMOTION. 635 grammar, taste, and cadence, as fast as the voice can utter them, is an object interesting to study in the present con- nexion. The Itahan Improvisatori furnish a still higher example. The sufficiently rapid action of the associating forces is here of prime importance. Eeal power is not usually identified with a specific pace of mental movement — a slow action may be as effective as a quick ; but, in this particular instance, the ready revival of all the associations that concur in the common stream is the main element of success. FINE ART CONSTRUCTIONS— IMAGINATION.* 23. The grand peculiarity of the case now to be con- sidered is the presence of an emotional element in the combinations. In the constructions of science and of practice, a certain end is to be served — the attainment of truth, or the working out of a practical result ; and the mind has to choose means suitable to those ends, according to the rigorous laws of nature's working. A builder has to erect a structure that will defy the weather, and accommodate a certain number of human beings. Nothing must enter into his plan that is not calculated to effect these purposes. The construction is considered a pure effort of intellect, because it is by intellect that we comprehend the laws and properties of stone, wood, and iron, and choose out and combine such materials as will serve for warmth and shelter. AVe should not properly call this operation ' im- aginative,' although there is a constructive process gone through ; simply because no feeling or emotion enters in as an element, excepting the one feeling of answering a * The word ' Image ' has come to be used in a much wider signification than the term 'Imagination'. This may be one cause of the undue exten- sion given to the latter term, by making it co-extensive with all the forms of original constructiveness, such as Invention in Science and the Useful Arts. Other causes may concur to what must be pronounced an abuse of the term in question. As regards the word ' Image,' the necessities of subjective nomenclature may have to do with its frequent employment as a synonym for the all-important term ' Idea,' by which we designate the mental trace or intellectual survival of our various sense im^jressions. 636 CONSTRUCTIVE ASSOCIATION. practical end. Volition there is in abundance, but not emotion as understood in the constructive processes of the imagination. AVhen, however, any practical construction, such as a building, in addition to the uses of shelter and accommoda- tion, is intended to strike the refined sensibilities that we term the feeling of the beautiful, the grand, the picturesque, a turn must be given to the plan so as to involve this other end. Here, we have emotion viewed in a certain narrow sense, as exclusive of the feeling of direct utility for the wants and necessities of life. Securing such pleasures as these, and warding off the opposite pains, and all pains connected with our physical organs, are among the ends of 'practical art. When such practical ends are secured, there are other feelings and sentiments belonging to human nature that can be touched in a way to increase the sum of human happiness. These are variously called the pleasures of Taste, the aesthetic sensibilities, the emotions of Fine Art ; and com- binations shaped with the view of gratifying them are called artistic, sesthetic, or imaginative compositions. In all such compositions, an element of refined emotion is the regulat- ing power, the all in all of the creative effort.* * The following passage will aid us iu working out the distinction between the constructions of imagination and the constructions of science and practice : — ' The trains of one class differ from those of another, the trains of the merchant, for example, from those of the lawyer, not in this, that the ideas follow one another by any other law, in the mind of the one, and the mind of the other ; they follow by the same laws exactly ; and are equally com- posed of ideas, mixed indeed with sensations, in the minds of both. The difference consists in this, that the ideas which flow in their minds, and compose their trains, are ideas of different things. The ideas of the lawyer are ideas of the legal provisions, forms, and distinctions, and of the actions, bodily and mental, about which he is conversant. The ideas of the merchant are equally ideas of the objects and operations, about which he is concerned) and the ends towards which his actions are directed ; but the objects and operations themselves are remarkably different. The trains of poets, also, do not differ from the trains of other men, but perfectly agree with them in this, that they are composed of ideas, and that those ideas succeed one another, according to the same laws, in their, and in other minds. They CONTRASTS WITH IMAGINATION. 637 24. In adducing examples of combinations controlled by an emotional element, I shall not confine myself to the narrowest class of artistic feelings, the feelings of Taste properly so called ; the fact being that, even in the creations of the artist, all the strong emotions may come in to swell the cm-rent of interest, excepting only a few of the more are ideas, however, of very different things. The ideas of the poet are ideas of all that is most lovely and striking in the visible appearance of nature, and of all that is most interesting in the actions and affections of human beings. It thus, however, appears most manifestly, that the trains of poets differ from those of other men in no other way, than those of other men differ from one another ; that they differ from them by this only, that the ideas of which they are composed, are ideas of different things. There is also nothing surprising in this, that, being trains of pleasurable ideas, they should have attracted a peculiar degree of attention ; and in an early age, when poetry was the only literature, should have been thought worthy of a more particular naming than the trains of any other class. These reasons seem to account for a sort of appropriation of the name Imagination to the trains of the poet. An additional reason may be seen in another circum- stance, which also affords an interesting illustration of a law of association already propounded; namely, the obscuration of the antecedent part of a train, which leads to a subsequent, more interesting than itself. In the case- of the lawyer, the train leads to a decision favourable to the side which he advocates. The train has nothing pleasurable in itself. The pleasure is all derived from the end. The same is the case with the merchant. His trains are directed to a particular end. And it is the end alone which gives a value to the train. The end of the metaphysical, and the end of the mathe- matical inquirer is the discovery of truth ; their trains are directed to that object ; and are, or are not, a source of pleasure, as that end is, or is not, attained. But the case is perfectly different with the poet. His train is its. own end. It is all delightful, or the purpose is frustrate. From the established laws of association, this consequence unavoidably followed ; that, in the case of the trains of those other classes, the interest of which was concentrated in the end, attention was withdrawn from the train by being fixed on the end, that, in the case of the poet, on the other hand, the train itself being the only object, and that pleasurable, the attention was wholly fixed upon the train ; that hence the train of the poet was provided with a name ; that, in the cases of the trains of other men, when the end only was interesting, it was thought enough that the end itself should be named, the train was neglected. ' In conformity with this observation, we find that wherever there is a train which leads to nothing beyond itself, and has any pretension to th& character of pleasurable (the various kinds of reverie, for example), it is allowed the name of Imagination. Thus we say that Rousseau indulged his. 638 CONSTRUCTIVE ASSOCIATION. exclusively animal feelings. Terror, rage, egotism, are not primarily aesthetic emotions ; still the artist uses them in his compositions. I should also remark that the influence of the emotion, while just and legitimate in the artistic sphere, is usually a source of corruption and bias in the combinations that have truth or practice for their end. This is what is meant by saying that imagination is not to occupy the place of judgment and reason. The emotion of Terror gives a character to all the ideas or notions formed under the influence of the feeling. A man once thoroughly terrified sees only objects of dread. It is •difficult to form any combinations free of this element. ■Ghosts and hobgoblins fill the imagination of the super- stitious, while more substantial forms of evil haunt a mind unaffected by the dread of the supernatural. The terrified imagination is powerful to form creations of terror, such as may prove an interesting excitement to the cool spectator, but which are also likely to vitiate the truth of any narra- tive of matter of fact given out under the influence of the moment. Hence, the accounts that a terror-stricken and imagination, when, as he himself describes it, lying on his back, in his boat, •on the little lake of Vienne, he delivered himself up for hours to trains, of which, he says, the pleasure surpassed every other enjoyment. ' Professor Dugald Stewart has given to the word Imagination a tech- nical meaning, without, as it appears to me, any corresponding advantage. He confines it to the cases in which the mind forms new combinations ; or, as he calls them, creations ; that is, to cases in which the ideas which compose the train do not come together in the same combinations in which sensations had ever been received. But this is no specific difference. This happens in every train of any considerable length, whether directed to any end, or not so directed. It is implied in every wish of tlie child to fly, or to jump over the house ; in a large proportion of all his playful expressions, as puss in hoots, a hog in armour, a monkey preaching, and so on. It is manifested in perfection in every dream. It is well known that, for the discovery of truths in philosophy, there is a demand for new trains of thought, multitudes of which pass in review before the mind, are contemplated, and rejected, before the happy combination is attained, in which the discovery is involved. If imagination consists in bringing trains before the mind involving a number of new combinations, imagination is probably more the occupation of the philosopher tlian of the poet ' (Mill's Analysis, vol. i. p. 181). EXAMPLES OF IMAGINATIVE CONSTRUCTIVENESS. 639 routed army relate as to the numbers and power of the enemy on its heels ; hence, the exaggerations that prevail in the public mind on occasions of popular panic. We see the power of an emotion, not merely to give its own character to the conceptions formed on all subjects, but to induce behef in the full and exact reality of such conceptions. With reference to examples of constructiveness of the class now cited, I may repeat the remark already made, to the effect that no new principle of association is at work in making an original combination ; the only thing requisite being the presence or concurrence of the proper ingredients, as furnished by the working of Contiguity and Similarity. When these ingredients appear in the mind together, they fall into their places as a matter of course. In the present instance, and in all imaginative or emotion-ruled combina- fiions, the laws of association can be show^n to be sufficient to furnish the constituents of the combination; for, we know that each strong feeling or passion has, associated with it in the mind, a large number of kindred objects, in consequence of the previous frequent companionship of such objects with the feeling. The passion of terror is connected with the things that have roused the feeling in the course of each one's experience : one man has associations between it and a cruel parent or master, another with money losses, a third with attacks of illness, a fourth w^ith defamation, a fifth with religious workings ; and most men are familiar with a plurahty of causes of dread. When, therefore, the feehng is once excited, no matter how, these often-experienced adjuncts start up and possess the mind, and mix themselves with the other ideas of the situation, so as to constitute a medley or compound of images, with terror as the predominating tone. Seeing the approach of a hurried messenger with distracted countenance, the trader's mind is already full of disasters at sea or depressions of the market, the parent of a soldier is made to think of the calamities of warfare, the usurper is ready with the anticipation of a popular rising. An exactly parallel illustration might be given from the 640 CONSTRUCTIVE ASSOCIATION. passion of Anger. Once roused, this passion resuscitates the objects in harmony with it, and puts together combina- tions wherein these enter as elements. The fanaticism of rage and hatred ascribes every diabohcal impulse to the un- fortunate object of the feeling ; all the things that have cus- tomarily inspired anger are brought forward by contiguous association, and the instigator of the present outburst is looked on as guilty of innumerable crimes, in addition to the offence of the moment. This is an extreme case, but not unexampled in the history of the world. Party-rage brands opponents with the most unheard-of crimes ; the term, ' calumny,' expresses this surplus of accusation against those that have excited the passion of hate. 25. The purely Egotistic feelings are remarkable for the superstructure of imaginative creations that they can rear. Self-complacency suggests merits and virtues, and constructs an estimate of self most flattering. Vanity sets up pictures of admiring assemblies and devoted worshippers. But most curious of all, are the day-dreams of ambition in a sanguine temperament : these will embrace a whole history of the future, the baseless fabric of a vision of wonders and triumphs, which is not only constructed without labour, but whose construction no labour can arrest. In former sections, we have adverted to the difficult efforts of constructiveness : we have seen how hard it often is to comply with the numerous conditions that a construction must fulfil, or to give a place to all the ingredients that should be represented in it — so much so, that the attempt may have to be repeated time after time, before everything falls into the proper places. A scientific man framing a definition for a very com- prehensive class of objects, a mechanician constructing a new machine, a politician devising a state expedient, a general circumventing a hostile army, — will be each engaged in deliberations, for days or months, ere the proper combinations occur to the mind. One suggestion includes something to be avoided, another omits something that ought to be present, and long delays and repeated substitutions and trials precede EMOTIONAL CONSTRUCTIVENESS. 641 the successful termination of the struggle. But, in the case now supposed, all is different : stupendous constructiveness, unbounded originality, flow out at once as fast as thought can evolve itself. Wherein lies the remarkable difference in these two forms of constructiveness ? The immortal crockery merchant constructed, in a few minutes, a lengthened fiction, totally distinct from anything he had ever seen realized in actual life. Why has emotion such power ? The answer is simple. A predominating emotion, such as Ambition, is every day at work associating itself with objects and incidents suited to gratify it. The feeling is called into play by every spectacle of power and grandeur that meets the eye, or is presented in story. The associating link is soon forged in t)ie hot fire of passion ; and, after months and years of indulgence of a favourite emotion, a rich growth of the corresponding objects and ideas is formed and ready to flow out, at any moment when the feeling is roused. Imagination in those circumstances becomes a power needing restraint, rather than an effort of laboured constructiveness. The foregone associa- tions with the feeling are so copious, that they present them- selves freely for any purpose. JI!onstruction is easy, where materials are abundant and the conditions few: the owner of the crockery-basket had amassed pictures of happiness and grandeur, which required only to be cast into a consecutive order to make his epic, and an extempore effort was enough for this. The onlv condition was to satisfy one feeling ; all restrictions were thrown aside, and he had plenty of images to suit the single emotion that lorded it over his dream. Very different would have been the pace of his execution, if he had insisted that this foreshadowing of his career should be in accordance with the stern experience of human life ; if his picture should have been regulated by natural calculation, founded on known realities. This would have dried up his facility in a moment ; he would then have been in the con- trasted position, above described, of the man of science, or the man of business : a feeling might have still been the end, but purely intellectual estimates of the facts and laws of the 41 642 CONSTRUCTIVE ASSOCIATION. world would have entered into his construction of the means. The reconciliation of his desires with the resources of his position would have been as arduous as a string of airy successes was easy. The process might have had ever so much of the constructive intellect, and the combination might have been ever so original ; but the term 'imagination' would no longer be used to describe it. 26. The Fine Art emotions, properly so called, — the emotions of harmony, beauty, sublimity, picturesqueness, pathos, humour, — become associated, in the artistic mind, with the objects that radiate the influence on the beholder. From the materials thus stored up and reproduced by association, the artist makes his constructions, I have, in a former chapter (Contiguity, p. 471), adverted to the mental equip- ment suitable to the artist in any department ; and it is scarcely necessary to repeat, what I have endeavoured to illustrate, throughout the present chapter, that, when all the elements are present that fit into a particular construction, they will take their places as a matter of course. The labour consists in getting up the constituent parts from the repositories of the mind, and in choosing and rejecting until the end in view is completely answered. Because the imaginations of a dreamer are easy and fluent, it does not follow that the imaginations of a musician, an architect, or a poet, shall be equally easy, — although in principle the same, being governed by an emotion powerfully developed and richly associated with material. The artist has more strin- gent conditions to fulfil than the dreamer. He has to satisfy the reigning feeling of his piece, — the melody, harmony, pathos, humour, of the composition ; he has, also, to make this effect apparent to the minds of others; he has, moreover, to exclude many effects discordant to the taste of his audi- ence ; and, if his work be the decoration of some object of common usefulness, he has to save the utilities while in search of the amenities. Every new restriction adds to the difficulty of a combining effort ; and an artist may be so trammelled with conditions, that the exercise of imagination THE CONSTRUCTIONS OF WIT. 643 shall be rendered as laborious as any construction of the reason. To call up combinations that produce powerful and rich effects upon the minds of men is not easy in any art ; but the gathered abundance of the artistic intellect is the secret of the power. The more rich the granary of material, the more is the artist prepared to submit to the numerous conditions involved in a really great performance. The rapid constructions of the genius of wit are a pecuHar case under the general principle, embracing all the recognized conditions, with certain psychological peculiarities illustrative of the more abstruse workings of consciousness. We have seen already that the stream of thought is a combination of suggestions entering the field of conscious- ness, with others lying outside but ready, not merely to come into the held, but to make combinations with what is already there. When Jerrold was accosted by some one in his company who stood in dread of his wit, with the remark, ' Mr. Jerrold, you'll not make a butt of me,' Jerrold replied, ' Then don't bring your hogshead here '. The transition, m Jerrold's m.ind, from 'butt' to ' hogshead,' as a synonj-m, must have happened out of consciousness, together with the concmTing sense of an effective retort ; only the conclusion coming into the conscious area. This is the case sometimes alluded to in connexion with profound reasoners like Newton, who arrived at mathematical inferences without being conscious of the steps that led to them. The situation is not limited to flights of the highest genius, but enters into the workings of thought in minds generally. It has come before us on several occasions, in connexion with the associative power of Recency. 27. I do not purpose at present to enter upon a minute illustration of the mental processes of Art-construction. Not only would a large space be requisite for spreading out the ex- amples in detail, but there would soon come to be involved a strenuous polemical discussion, in consequence of the prevalence of theories of art that seem to me erroneous. Conceiving, as I do, that the first object of an artist is to gratify the feelings of taste, or the proper aesthetic emotions, I cannot assent to the current maxim that nature is his standard, or truth his chief end. On the contrary, I believe that these are precisely the conditions of the scientific man ; he it is that should never deviate from nature, and that should care for truth before all other things. The artist's standard is feeling, his end is refined pleasure ; he goes to nature, and selects what chimes in with his feelings of ai'tistic 644 CONSTRUCTIVE ASSOCIATION. effect, and passes by the rest. He is not even bound to adhere to nature in her very choicest displays ; his own taste being the touchstone, he alters the originals at his will. The scientific man, on the other hand, must embrace every fact with open arms ; the most nauseous fungus, the most loathsome reptile, the most pestilential vapour, must be scanned and set forth in all its details. The amount of regard that the artist shows to truth, so far as I am able to judge, is nearly as follows. In the purely effusive arts, such as music or the dance, truth and nature are totally irrelevant : the artist's feeling, and the gratification of the senses of mankind generally, are the sole criterion of the effect. So, in the fancies of decorative art, nature has very little place : sugges- tions are occasionally derived from natural objects; but no one is bound to adopt more of these than good taste may allow. No- body talks of the design of a calico as being true to nature ; it is enough if it please the eye. ' Art is art, because it is not nature.' The artist provides dainties not to be found in nature. There are, however, certain departments of art that differ considerably from music and fanciful decoration, in this respect, namely, that the basis of the composition is generally something actual, or something derived from the existing realities of nature or life. Such are painting, poetry, and romance. In these, nature gives the subject, and the artistic genius the adornment. Now, although, in their case also, the gratification of the senses and the aesthetic sensibilities is still the aim of the artist, he has to show a certain decent respect to our experience of reality in the management of his subject ; this not being purely imaginary, like the figures of a calico, but chosen from the world of reality. Hence, when a painter makes choice of the human figure, in order to display his harmonies of colour, and beauties of form, and picturesqueness of grouping, — he ought not to shock our feeling of truth and consistency, by a wide departure from the usual proportions of humanity. We do not look for anatomical exactness — we know that the studies of an artist do not imply the knowledge of a professor of anatomy ; but we expect that the main features of reality shall be adhered to. In like manner, a poet is not great because he exhibits human nature with literal fidelity ; to do that would make the reputation of a historian, THE artist's regard TO TRUTH. 64;j or a mental philosopher. The poet is great by his metres, his cadences, his images, his picturesque groupings, his graceful nar- rative, his exaltations of reality into the region of ideality ; and if, in doing all this, he avoid serious blunders or gross exaggerations, he passes without rebuke, and earns the unqualified honours of his genius. 28. The attempt to reconcile the artistic with the true, — art with nature, — has given birth to a middle school, in whose productions a restraint is put upon the flights of pure imagi- nation, and which claims the merit of informing the mind as to the realities of the world, while gratifying the various aesthetic emotions. Instead of the tales of Fairy-Land, the Arabian Nights, the Eomances of Chivalry, we have the modern novelist, with his pictures of living men and m.anners. In painting, we have natural scenery, buildings, men, and animals, represented with scrupulous exactness. The sculptor and the painter exercise the vocation of producing portraits that shall hand down to future ages the precise lineaments of the men and women of their generation. Hence, the study of nature has become a main element in artistic education ; and the artist often speaks as if the exhibition of truth were his prime endeavour, and his highest honour. It is probably this attempt, to subject imagination to the conditions of truth and reality, that has caused the singular transference already mentioned, whereby the definition of science has been made the definition of art. Now, I have every desire to do justice to the merits of the truth-seeking artist. Indeed, the importance of the recon- ciliation that he aims at is undeniable. It is no slight matter to take out the sting from pleasure, and to avoid corrupting our nations of reality, while gratifying our artistic sensibilities. A sober modern romancist does not outrage the probabilities of human life, nor excite delusive and extravagant hopes, in the manner of the middle-age romances. The change is in a good direction. Nevertheless, there is, and always will be, a distinction between the degree of truth attainable by an artist, and the degree of truth attained by a man of science or a man of business. The poet, let him desire it never so much, cannot 646 CONSTEUCTIVE ASSOCIATION. Study realities with an undivided attention. His readers do not desire truth simply for its own sake ; neither will they accept it in the severe forms of an accurate terminology. The scien- tific man has not wantonly created the diagi'ams of Euclid, the symbols of Algebra, or the uneouthness of technical Anatomy; he was forced into these repulsive elements, because, in no other way, could he seize the realities of nature with precision. It cannot be supposed that the utmost plenitude of poetic genius shall ever be able to represent the world faithfully, by discarding all these devices in favour of flowery ornament and melodious inetre. We ought not to look to an artist to guide us to truth ; it is enough for him that he do not mis- guide us. APPENDIX. A. — DeHnitiun and Divisions of Mind. — p. 7. I. Matiud Solidarity of the Three Power.^. — It is made a question whether the three fundamental properties of mind can operate in separation, or whether they are always and necessarily co-present though in different degrees of comparative intensity. The most rigid view of their essential solidarity compares them to the inseparable qualities of solid matter, — as, for example, size, shape, and colour. Every known solid possesses these three attributes, as its very essence ; we could not withdraw one of them, or form a conceivable compound of two. We may have all varieties of proportion in the composition of a solid mass, but no absolute separation. So it is contended that, in every act of mind, although one of the three constituents may preponderate, yet the two others must also be operative, however feeble may be the degree of their activity. The analogy thus employed is by no means a close one. The composition of a piece of matter, and the concurrence of the great fundamental facts of mind in a conscious exercise, are so widely disparate in character that we cannot reason from one to the other with any assurance. Indeed, the points of difference are of a very serious character. If we take the colour, size, and shape of a mineral mass, we can suppose any one of the three qualities changed to any amount, without change in the two remaining. In tlie case of the mental aggregate, a change cannot be made in any one constituent without affecting the degree and direction of the others ; sometimes in the way of increase, at other times, in the way of diminution. Among the fundamental laws of mind, we include statements of the mutual action of the three great powers — as in the well- known principle of the inverse relationship of Feeling and Thought. Without finally deciding the main question, this circumstance is sufficient to destroy the value of the analogy drawn from a portion of solid matter. A closer comparison might be found with the organs of the 648 APPENDIX. animal body, which are severally and collectively indispensable to the life of the organism, while they are not all equally in opera- tion at every moment. Some, as the heart and the lungs, can never be remitted, nor lowered in energy beyoiad a certain point ; others, as the stomach and the brain, can be inactive for hours together. This, too, fails to represent the mode of concui-rence of the three powers of the mind. Abandonmg the search for analogies, our course is to look at the facts themselves as they come out in the exposition of the mind. Several important doctrines are connected with the rela- tive preponderance of the different fundamental powers, and with the all but total abeyance of one or other on certain occasions. II. Order of Depnidence or Causatiun of the Three Poirers. — The threefold division of mind seems to have been first explicitly made in Germany, in the last century, by certain almost forgotten psychologists who flourished in the interval between Wolf and Kant. In so far as Kant troubled himself at all about psy- chology, or required psychological data, in executing his task of criticizing the foundations of human knowledge, it was to the works of these, his immediate forerunners, that he had recourse. Thus, he follow^ed their principle of the threefold division in lay- ing out the parts of his whole critical undertaking ; the Critique of Pure Rfoaon corresponding to Intellect or the power of Cogni- tion, the Critiijue (f Practical Reason to Will or Action, and the Critique of the Facidty of Judgment to Feeling of pain and pleasure. But it was no part of his plan to work out the principle in a psychological exposition of mind. That the three great leading functions of mind — Feeling, Will, Cognition — act and re-act on each other in a variety of forms, has been made abundantly manifest in the course of the exposition. Feeling contains the motives to the Will; Intellect or Cognition influences the feelings and is influenced by them. The precise circumstances and conditions of these re-actions are treated in the places most suited to their exemplification. A much closer and more vital dependence of the three powers upon one another has been contended for. Hamilton holds that Cognition is the foundation of everything. He says, ' every mental phenomenon is either an act of knowledge, or only possible through an act of knowledge ; for consciousness is a knowledge — a phenomenon of cognition '. Eeferring to a number DEPENDENCE OF THE THREE PRIMARY POWERS. 64'.> of German philosophers, who hold the faculty of cognition to he the source or origin of all the others, he says, this is going too far. For, ' although pleasure and pain, desire and volition, are only as they are known to be ; yet, in these modifications, a quality, a i>heni>mi:nou of mind, ahmlutelij iieir, Jtax been saperarhhd, which was never involved in, and could, therefore, n^ver have been evolved out of, the mere faculty of knowledge '. This consideration, however, so apparently decisive, has had no weight with German psychologists : Herbart and his followers deduce from purely cognitive processes all the varieties of Feeling, while these in their turn (as admitted universally) are the movers of the Will. According to Herbart, the foundation circumstance in the play of the intellect is the combination and interaction of certain ultimate mental states, initiated from without ; which states are nau:ed pre.^<_'ntaii()n.^. They include both the sensations of the senses and the ideas that these give rise to. The manner of coming and going of these presentations, of their appearing and disappearing, their conflict and concurrence, is the basis of all the explanations of the Intellectual powers. Presentations of contrary quality exclude each other from consciousness : the weaker is said to suiYer amd. The full bearing of this mode of viewing the intellectual powers will be considered again (see note G). The reference here is solely concerned with the genesis of Feeling, or Pleasure and Pain. When diiTerent presentations, — sensations or ideas — occui'- ring together, are so far of congenial nature as to support each other in consciousness, there is, as it were, a surplus of conscious energy, and that surplus is pleasure. The obverse situation is pain. In all the explanations offered in regard to pleasure and pain, the harmony or conflict of concurring states is always put forth as an important circumstance, and as regulating one class of cases. It has miich to do with the pleasures of Fine Art, in which harmony plays a leading part. Now, in order to explain our purely sensuous pleasures, Herbart has to make an altogether gratuitous assumption, — namely, that these are made up of con- curring presentations, no longer separately discernible. It is impossible to adduce evidence either for or against this view, and, as a hypothesis, it gives no help to the understanding of sensation. The doctrine is repeated by Volkmann, and illustrated in great detail, but without any attempt to relieve its difficulties. 650 APPENDIX. ' Feeling (pleasure and pain),' he says, ' isthe becoming conscious of the degree of tension of the representative activity. But the tension is the state of the representative activity, either pressed down by its arrest, or freeing itself from it.' The one case is Pain, the other Pleasure. Yolkmann uses ' representation ' to cover both sensations and ideas ; each representation has its content, or meaning, and its energy, intensity, or activity, according to which it asserts itself in the conflict with other representations. The sum of all w^hich is, as in Herbart, that a single presentation or representation has an intellectual value, but does not give birth to feeling proper. When pleasure or pain is the result of a solitary stimulus, — as a sweet sound, a brilliant flame, or a bitter taste, there is a hidden and inscrutable concurrence or conflict of simpler states. I need only repeat that the entire doctrine is a pure fiction beyond the reach of evidence. For, while many forms of pleasure and pain are due to the concurrence or collision of distinct sensations and ideas, many other forms result in the plainest manner from single or individual stimuli, and are to be recognized as such. I turn next to the mode of stating the fundamentals of mind adopted by Dr. Ward, who, while freely embodying the German psychology, casts aside the doctrine of plui'al presentations as essential to Feeling. He, nevertheless, maintains that the pre- sentation, viewed as a strictly cognitive element, is the origin or cause of our pleasurable and painful states. The problem of Psychology, according to Dr. Ward, ' is, in general, first, to ascertain the constituent elements of mind, and secondly, to ascertain and explain the laws of their com- bination ' . Now, it seems to me that an Introduction may properly in- clude a statement of the constituent elements of the mind, as highly generalized, and as clearly defined as possible, provided their meaning can be imparted at that stage. And further, if the laws of their combination can also be stated, in a sufficientlv intelligible form, these laws may be enunciated in anticipation — like the Laws of Motion in Mechanics, and the Atomic Theory in Chemistry. While Dr. Ward's statement of Elements is in the usual form, — Feeling, Cognition and Will,- — his formula for their relation- ship and mutual action, is peculiar and not over-intelligible to the beginner. FUNDAMENTALS ACCORDING TO DR. WARD. 651 He opens by remarking that when we say I feel, I will, I think, the three properties are stated as the predicates of three propositions with a common subject — '/'. Who or what is 7 .? Is it merely a convenient form, of the natm^e of a fiction, or is it an essential factor in the enmiieration of the powers or attributes of mind? If the latter, we must assign four, instead of tliree, essentials, and must give some adequate definition of I to start with. The author does furnish some reasons for laying out the mind under the plan of Objects, presented to a Subject. These objects are first, Cognitions, second, Feelings, third. Movements. The efficiency of the whole operation depends vitally upon a grand store of energy located in the subject, and coming into play under the stimulus of the Senses, or whatever else ' Presentation ' covers. The awakened energy of the subject is designated by an old familiar word — Attention. The quality so expressed is all-impor- tant : it is the means of converting a Cognitive fact (as a sensa- tion of one of the senses) into Feeling ; and of further converting a Feeling into a Movement, — which is Will. Considering this enormous ascendency of the Subject, through its power of Attention, we may fairly ask a more special account of its history and constitution. How come we to have such an agency? Is it intuitive, as many would be willing to think, or is it one of our acquisitions or growths ? Has it anything in com- mon with what is called, in other connexions, our Self, Person- ality, or Ego, which is regarded as a work of years to mature? Once more, how is it disentangled from the elements that make its vis-a-i-is in the psychological mechanism ? Did these contri- bute to its first formation, and afterwards take up tlieir position in the way supposed? I understand Dr. Ward to maintain that, without this di^dsion of the mind, we should have propositions all predicate and no subject — a logical absurdity. It is an old remark, that knowledge supposes a mind knowing, as well as a thing known. There must be some way of reconciling this demand ; only, we must beware of plunging into still greater difficulties. The most staggering circumstance in the whole scheme is the power given to x\ttention to evolve Feeling out of w'hat is properly Cognition, or Intellect. No doubt, Herbart and his followers took the lead here, and Hamilton gave a qualified concurrence. As a theory of Pleasure and Pain, the speculation, in all its forms, seems to me at variance with fact. 652 APPENDIX. The final analysis of Mind, according to Dr. Ward, consists in recognizing three distinct and irreducible facts: attention, feeling, and objects — or presentations. Now, according to him, there are two ways of determining attention : (1) the sensory or receptive state, when attention is non-volimtarily determined — i.e., where feelin'j follows the act of attention ; and (2) the motor or active state, where feeling precedes the act of attention, which is then determined voluntarily. If the first of these two positions were as obvious as the second, it might be admitted as a generality to be unfolded and established in the course of the exposition. That Feeling, once aroused, brings forth Movement or Action, is the statement of the Will ; pleasurable feeling operating in one direction, painful feeling in the other. The nature of the link betvi^een the two things gives rise to much subtle discussion ; but the main circum- stance is received as indisputable. It is very different with the first position, which deals with the production of Feeling, from presentations, under the strain of Attention on the part of the Subject. Let us take the wording of it in the tabular scheme. The stages are these : — (1) sensory objects presented to the Subject ; (2) these objects make changes in the sensory-continuum ; (3) we attend (non-voluntarily) to these changes ; (4) we are, in consequence, either pleased or pained ; to which follows the second stage of operations for bringing the Will into exercise. To complete the theory, the author adds, in a note, that trains of ideas have the same efficacy as changes in the seusory-continuum. While the theory of the Will is, so far, a manageable problem, the theory of Pleasure and Pain is the abstrusest question of Psychology. In vain have we endeavoured to generalize the production of feeling into one comprehensive source. Dr. Ward's formula, given above, must be regarded in the light of his sub- sequent explanations, which in great part agree with the views more or less prevalent. By leaving the Subject so completely undefined, he does not show the way out of the following difficulties : — (1) If change of sensory experience, in the shape of new pre- sentations, with the aid of attention, be the source of our feelings, there should be some attempt to deal with the numerous excep- tions — namely, the cases where such change does not produce feeling, and the cases where, apparently at least, we have strong INTELLECTUAL FOUNDATION OF FEELINGS INADEQUATE. 653 feelings without conscious sensory change, and, therefore, also without attention. That a very large number of our sensations, although fully attended to, yield neither pleasure nor pain, but only intellectual imagery, is too evident to be disputed. Dr. Ward, at a later stage, makes allowance for this, and affords various hypothetical explanations. But a position so very open to exceptions ought to be more guarded, even on its first announcement, as a com- manding generality of all mind. (2) More serious, because more palpable, is the other objection, namely, that many of our pleasures and pains arise without any antecedent presentation to the Subject. Change, no doubt, there must be somewhere, but while the effect is conscious, the pro- ductive cause escapes our consciousness, and never reaches the subject. The strong cases here are to be found among our Organic Sensations. While many of the pleasures and pains arising in this region have their conscious sensory precursors, many have not. Wakening in a dark room, and in perfect stillness, we fall into a condition of organic pleasure or pain, without knowing w'hy. There are changes taking place in the system that would fully account for this, but not in the form of sensory change acting on attention. Should there be a certain amount of ambiguity in the situation, owing to our consciousness of passing out of sleep into the waking condition, this is removed in the alternations of feeling throughout the day, apart from the known occasions of taking food, exercise, or rest. Our state of feeling passes through many gradations, to which no conscious antecedent can be assigned. Physiological science aids us in conjecturing what the changes are, and the theory of pleasure and pain embraces this situation ; but, without great forcing, it could not come under Dr. W^ard's formula. The same observation applies to our sudden attacks of internal pain, such as cramp, or neuralgia, which come without any assignable antecedent. No doubt, they bring a sensoi'y or cogni- tive experience with them — we not only feel them as suffering, but we cognize them as a characteristic I'evelation to our intelli- gence ; but this does not prove that the cognitive property is the cause, and the suffering the effect. (3) There are innumerable cases of the production of feeling, where the safest view to take is, 'that the cognitive and the hedonic 654 APPENDIX. elements are simply concurring or coincident, without assignable causation on either side. After being fully manifested in con- sciousness, the two act and re-act in understood ways, but neither owes its first origin to the other. In the pleasures and pains of the five senses, there is always an intellectual presentation ; and, in some cases, a plurality, — as where an object affects several senses, for example, a piece of sugar. The tasting property of sugar is a mixture of two effects ; it is a pure assumption to say that either causes the other, seeing that in so many of our organic states there is feeling with no assignable antecedent of the nature of a sense presentation. The more usual explanation of the higher instiiictive emotions, as Love and Anger, is that they are accumulated and hereditary associations of sociable feelings with certain sensory objects. The occurrence of the object is the occurrence of the feeling, not as cause and effect, but as blended or united qualities. Before the association was formed, the image of another personality would have no power to induce the emotion of love or hate. This is the assumption that best fits the ordinary senses, as well as the imagery that grows out of their exercise. A cognitive presentation in abstract purity, giving birth to a pleasurable or painful feeling, is a possible supposition in certain circumstances ; while the concurrence of several presentations, individually barren and feelingless, may, through the fact of coalition, be a cause of pleasure or of pain ; but this case is still less fitted to represent the whole compass of our feelings. Everything is more or less vague, until we settle precisely what is included in the Subject. If it is the permanent aggregate of mental growths, in all the three spheres, its capacities of respond- ing to presentation and stimulation are, without doubt, very numer- ous. Nevertheless, the production of feeling by awakening echoes of the past may be expressed better, without the assumption we are now discussing. B. — Pleasure and Pain. — p. 317. The principle mentioned in the text as modifying the law that connects pleasure with increase and pain with diminution of vital force — the principle of Stimulation — covers and includes various laws more or less recognized in our common experience. The connexion of Pleasure with Eemission or Change, in other words, LAWS OF PLEASURE AND PAIN. 655 the law of cessation and change of stimulus, as culminating in the well-known pleasures of Novelty, does not exactly coincide with the law of vitality. Interval of time, according to this further principle, has an absolute vcdue, and is not simply relative to nourishment of tissue. A week's confiaement, with privation of all muscular exercise, would impart a peculiar zest or relish to the I'esumption of the usual activities; while, in point of fact, the muscular organs would be in a far worse condition than if they had been put through their accustomed daily exercise. When General Wolseley disembarked in Egypt, with an expeditionary force, he found his operations retarded by the inability of the horses to gallop ; yet, we may be quite sure that their enjoyment of the free use of their limbs was much greater than their ordinary delight in the daily exercise of them. There is no necessary contradiction or contrariety between the law of change for the sake of change and the law of expenditure of renewed vigour. Nevertheless, the statement of the one needs to be supplemented, or somehow modified, to include the other. Only by an independent induction could we ascertain that the pleasm-e of a stimulus follows, in the first place, the nourishment of the organ, and, in the second place, the interval of remission. The two facts are distinct in their nature, and each needs to be studied on its own ground, and not to be inferred from the known workings of the other. An organ is at its very best, in point of preparation for activity, by being exercised, up to the proper limits, without the loss of a single day — as in the training of pedestrians, mountain-climbers, boxers, or athletes. The high physical condition thus gradually established yields its due amount of the pleasure of exercise ; but, to obtain the other pleasure, there must be longer periods of remission, even at the cost of inferior vigour in resuming the exertion. The same line of observations may be taken in regard to the more purely nervous and mental acti\aties. To keep up the intellectual energies to their highest efficiency, they need to be maintained in steady exercise, with due observance of the limits of over- fatigue. To gain the pleasures of freshness in any one mode of effort, there needs to be a much greater remission than is implied in their daily repose ; and, when that larger remission is allowed, as in school vacations, it is found that the renewed zest is accompanied with temporary falling off in efficiency. 656 APPENDIX. Thus, The law of vitahty or conservation, besides being directly contradicted by notorious cases of sense pleasures and pains, fails still more remarkably when we put it through the ordeal of measured concomitance. Acute pains are, no doubt, often connected with injury of some of the organs or tissues ; but there is no proportion between the acuteness of the pain and the injury to the parts aiifected : while, on the other hand, a very large number of deteriorating influences are either devoid of painful accompaniments altogether, or are so slightly productive of pain as to give no indication of the actual deterioration of the organs concerned. There is another notable aspect of this failure of concomitance. It is best brought out in the attempts to explain the pleasures of Fine Art, of which the most characteristic and essential are the effects due to complication and harmonious adjustment. The remarkable circumstance in connexion with harmony is the astonishingly intense pleasure attainable from its higher modes — that is to say, as the harmony increases, the pleasure also increases out of all proportion. What is there in a fine voice to make such an extraordinary impression on the senses and the mind, as compared with a more ordinary one ? The physical difference of the two is supposed to be resolvable into a readjust- ment of the over-tones that make up the special timbre of each ; and how such minute adjustments can suffice to make the difference between an average singer and Mario, or Jenny Lind, is utterly baffling in our present knowledge. There is a parallel difficulty in the delicacy of stimulants and articles of food, for which no explanation can as yet be offered. The same anomaly appears in aesthetic combinations of a still higher kind — as in a musical air or a poetical cadence. That a certain succession of notes, the so-called musical sentence or theme, should have a perennial charm to the human ear, is a fact that has been partly, but not fully, accounted for. The three circumstances that have been adduced by Sully and others, viz., musical concord of successive notes, intellectual unity, and expression of emotion — completely fail when applied to the extreme cases. For, as shown by Gurney, there is some residual element of fascination, at present beyond the reach of analysis. Possibly, the elements that have been assigned, and more especially the delicate expression of emotion, might suffice for the explanation, if our means of analysis and verbal definition STIMULATION AND THE LAW OF CEEDIT. 657 were equal to the subtlety of the case. As it is, we find ourselves face to face with an insoluble puzzle. The felicities of our poets have been subjected to a critical scrutiny by Gurney ; and, although the constituents are more tangible in poetry than in music by itself, he maintains, with apparent success, the inscruta- bility of the resulting emotion. To cite another example. The charm arising from the human form is partly explicable by circumstances that have been assigned, but with the same residual difficulty in accounting for the extraordinary rate of increase according as the points of excellence are refined upon. It is further worthy of remark, that stimulation is the ground- work of the law or principle of Credit, whereby we can attain present pleasure at the cost of the future. Like running into debt in the affairs of life, this is at once an essential of human efficiency and progress, and a region of our greatest tendencies to abuse. If the system never gave forth more response to pleasure than the strength of the moment could fully defray, we should no doubt be saved from ruinous temptations, but we should also be checked in our noblest and most legitimate efforts to improve the human condition. Yet, where such a licence exists, the principle that would connect pleasure and pain with increase and diminution of vitality, is conspicuously falsified or suspended. It is not merely the readiness to forestall the future for the sake of the present ; it is the absence of anj- adequate security for repayment when our means will allow it. The downgrade tendency of human life, the shortening of the natural period allotted to man on the earth, may be principally resolved into this particular outcome of the law of Stimulation. Review of Darivin cm ' Expression '. Charles Darwin, in his work, entitled The Expression of the Emotions in Man and Animals, has made very considerable additions both to the facts and to the theories of Emotional Expression — a subject handled at some length in the present volume. I propose to compare his conclusions with the views given in my chapter on the Instincts. Three principles are put forward as suinming up the facts. The first is entitled ' The Principle of Serviceable Associated Habits '. As an example, a frown accompanies and expresses states of pain, of anxiety, of deliberation, because it was originally useful in screening the eyes from the sun in circumstances of anxiety. 42 •658 APPENDIX. This principle implies three assumptions :— (1) Voluntary movement, or movement for ends, is an earlier fact than Emotional or purposeless movement. (2) Voluntary movements become associated with the feelings that occasioned them, so as to be manifested, although there is no proper act of the will. (3) These associated movements are transmitted by Inheritance. This last is the carrying out of Darwin's own doctrine of Evolution. The second principle is called ' Antithesis,* and is intended to account for certain cases where an expression is stimulated, not by a positive association with the feeling, but by a motive of antagonism or contra- diction to some established expression of the opposite feeling. Thus, a dog, in a savage mood, has certain movements and gesticulations posi- tively associated with his angry and aggressive passion, being the mcipient movements of a destructive onslaught ; a dog, in an affectionate mood, not having a positive endo^vment corresponding to affection, chooses the most exact contrast or opposition to his angry demeanoiu-. The third principle is 'The principle of actions due to the consti- tution of the Nervous Sj^stem, independently of the will fi'om the first, and independently to a certain extent of Habit' ; more briefly, it is stated as the principle of ' the direct action of the nervous system '. The reader of the present work will recognize in this what I have termed the Law of Diffiision. Darwin quotes the statement I have given of the law, and remarks that it ' seems too general to throw much light upon special expression ' — which is quite true i nevertheless, he himself em- ploys, for that Aery pmpose, a mode of stating it that I believe to be still more vague. The order of these principles is the inverse, or analytic order, which is, on some occasions, more convenient than the direct or synthetic. If we were to start from what is primitive or primordial, we should begin with the last-named principle, 'the dnect action of the nervous system ". The two others are subsequent and superinduced upon this ; more especially is that named first, which is the author's own law of Evolution or Inheritance, a later effect— or a growth or addition to the simpler process of nervous diffusion. Tlie characteristic feature of the book is the applying of Evolution to account for the phenomena of expression. The two other laws are less often appealed to. Wielding an instrument of such flexibility and range as the inheritance of acquned powers, a theorist can afford to dispense with the exhaustive consideration of what may be due to the primitive mechanism of the system ; he is even tempted to slight the primitive capabilities, just as the disbeliever in Evolution is apt to stretch a point in favom- of these origmal capa- bilities. ]\Iy readers are awai-e that I put great stress upon two primitive tendencies of the system, besides Diffusion — namely, the Spontaneity of Movements, and the Law connecting Pleasure and Pain with augmented and lowered vitality. Now, both of these powers, physically viewed, DARWIX ON EXPRESSION. 659 entei", with marked prominence, into the expression of the Feehngs. Darwin never mentions the doctrine of Spontaneity : he alhides to my statement of the Law of Pleasure and Pain, withoiit saying whether he agrees or disagrees with it in the general formtda ; but, in his detail of facts, he adduces many examples of it so striking that he cannot help expressing them in the phraseology of the principle. His second law, the law of Antithesis, to a small extent coincides with the law of Pleasure and Pain ; biit it is ill-fitted to supersede that law, as I will endeavovu' to show. Conceiving as I do, that the Spontaneity of Movements is a gi'eat fact of the constitution, with important consequences both emotional and vohtional, I will here pomt out its bearings on Expression. In so doing, I must define precisely what it consists in, and how far it reaches. By Spontaneity, I understand the readiness to pass into movement, in the absence of all stimulation whatever ; the essential requisite being that the nerve centres and the muscles are fresh and vigorous. We may never in our waking hoiu's be wholly free from the stimulation of the senses ; but, in the exuberance of nervous power, om* activity is out of all propoi'tion to the actual solicitation of the feelings. The gesticulations and the carols of young and active animals are, I conceive, mere overflow of nervous energy ; and although they are very apt to concur with pleasing emotion, they have an independent source : then- origm is more phj'sical than mental ; they are not properly movements of expression— they express nothing at all, except an abimdant stock of physical power. To obtain a correct estimate of the expression of joy, for example, the spontaneity must be allowed for and subtracted. This may not be very easy ; yet the separation of the two facts is quite supposable, and is occasionally realized. The spontaneity conciu-s with mornuig freshness, or with the oiitburst after confinement, and will show itself in the absence of pleasurable stimulants ; although these would operate in the same direction, and the two effects would be indistinguishable. The expression of pleasure is shown in isolation when the flush of spontaneity has passed by, and when a certain amoimt of exercise has drawn off the exuberant and surplus energy of the system ; it is also sho'uii in constitutions so languid or inactive as never to have any surplus. In a passage already quoted (p. 311), Darwm ob^^ouslJ' combines spontaneity with joyful expression. The first case cited by him — the demeanour of childi'en — is usually a mixtiu'e of exuberance and sportive pleasure ; the second — the dog walking out — contains a known element of pleasure ; the last — the frisking of the horse — is almost pure spon- taneity — it does not necessarily express Joy or Pleasme at all. The com'se taken in the spontaneous outbvu'st of movements is the most usual or habitual channels of activity. The locomotive nmscles are the first to be affected : actions that may have become habitual in tlie pur- suit of ends are excited piu'poselessly when the system is fresh. Kunning, jumping, shouting, talking, may be induced in this way. Any special 660 APPENDIX. trick or practice may be incited ; as when the dog, after reHeving him- self, vehemently scratches the ground. Survivals may be maintained by no otlier mode of exercise than wliat is stiunalated under the spontaneous discharge of activity. Assuming the scrapmg of the dog to be an action once useful, but no longer so, it would fall into disuse but for its bemg repeated in the moments of abounding energy. The most frequent mode of displaying exuberant force is in following . some pleasure that chances to be at hand, in itself perhaps trifling, and at other times utterly neglected. Finding ourselves in possession of productive energy, we seek occasions for turning it to account ; if great opportunities do not present themselves, we are content with small. This is one aspect of play, in children and in playful animals. The kitten is not seriously in love with a worsted ball, nor a dog with a stone ; but, under superabundance of nerve force, these trifling objects are so magnified as to become an inspiring pursuit. There is an exact par- allel in the desultory activity of men by nature incontinently energetic. The spontaneity due, not to natural exuberance, but to excitement, is equall}" devoid of meaning as regards feeling or emotion. The nervoiis centres are profusely active, and that is the whole fact ; the concurrence of some degree of pleasure or of pain does not alter the situation, although helping to complicate it. The causes of excitement are niimerous : there may be a mental state accompanying it, but the physical outburst does not represent a mental mood, it only gives evidence of the molecular energy of the nervous centres. A man under excitement paces his room, to and fro, sits down and starts up ; never rests in one posture. The excitement may be attended witli pleasure or with pain, with love or with hatred ; but these are not what the demeanour expresses. If the precise mood is expressed at all, it is bj' some display superadded to, and distingi;ished from, the general excitement. The extreme case is delirium — in which the violence of the movements has nothing answering to it in the mental condition : the delirious patient being often unconscious. As with natural exuberance, so with excitement, the movements are chosen and determined by the habitual channels of the nerve force, due to the circumstances regulating the life and activity of the individual. Inasmuch as locomotion is the prevailing mode of action, with all animals, excitement tends b}^ preference to rapid locomotive efforts. With excited human beings, the upper extremities gesticulate in some of the usual and characteristic actions — as in going through the formality of striking a blow. I will now advert to Darwin's handling of what I have been accus- tomed to style the Law of Diffusion. It is explained at length in the introductory chapter of The Emotions and the Will. By Darwin, the general principle is expx-essed thus : ' When the sensorium is strongly excited, nerve force is generated in excess, and is transmitted in certain definite directions, depending on the connexion of the nerve cells, and DARWIN ON EXPRESSION. 661 partly on habit ; or the supply of nerve force may, as it appears, be interrupted '. This statement does not sufiiciently distinguish the excited spontaneity of the centres from the effects due to a feeling. The proper law of Diffusion supposes a sensory stimulus — as light, sound, and odour — affecting the nervous centres, and, while accompanied by a state of pleasiu-e or pain, inducing a wave of movements and other effects by the outgoing nervous current. The start from a sudden shot exemplifies the diffusive nervous action ; and the general law of that action, as more explicitly promulgated by Spencer, is that the diffusive display, the energy of the gestici;lation and movements, is directly as the intensity of the stimulus or shock — a feeble sound, miexpected, gives a sUght dis- turbance ; a loud sharp soimd causes a violent start {The Principles of Psychology, i. 92). Darwin, in his concluding expression, ' the nerve force may be inter- napted,' allows for the cases where the severity of a blow paralyzes the nervous system. It is true of the diffusive display, caused by stimulating one of the senses, or by some emotion anyhow arising, as of the spontaneous dis- charge, that the channels selected by it will depend upon the structural connexions of the nerve centres, whatever may have brought about those connexions. Nevertheless, diffusion in response to a sensory or emotional stimulus, is more specially limited than spontaneity ; and, hence, the expressiveness and character of the movements under feeling. We shall see what are these various guiding and limiting circumstances. The follo^\-ing are a few of the instances where Darwin adverts to diffusion, or direct nervous actions :— He adduces, first, the sudden change of the colour of the hair, under terror or grief, as a case in pohit. He next brings forward a number of instances connected with the extreme forms of pam and terror, and dwells particularly on the muscular tremb- lings in fear. In contortions of pain, he remarks, that nearly every muscle of the body is brought into violent action ; admitting, however, that much of this excessive action is due to the promptings of the %vill to mollify the pain. Again, many of the signs of rage (not all) he attributes to the direct action of the excited sensorium ; not only the gestures and movements, but also the influence on the heart's action, and the circulation of the blood. Further, joy quickens the circvilation, and this stimulates the brain, which again reacts on the whole body. Also, terror, in all animals, causes tremblings of the body, relaxes the sphincter muscles, disturbs the heart and the breathing, and leads in the end to utter prostration, and even fainting. Pain and fear, if great, are depressing ; if not so great, they are stinnUating. These are the leading instances in the chapter expressly devoted to the principle of direct nervous action. A few scattered references occur in other chapters : the lashing and curling of the tail in animals under excitement (126) ; the sympathetic action of unnecessary nmscles, along with those that are at the time necessary (166), as in closing the eyes, and the mouth. 662 APPENDIX. These examples are, obviously, complicated with the effects special to pleasure and pain ; they are the very cases that I have always adduced in support of my view of the primary law connecting increased vitality with pleasurable, and diminished with pamful, emotion. The best example for diffusion by itself is Surprise or astonishment ; there being numerous instances, as I believe, of sm'prise without any marked degree of either pleasure or pam. It would appear, therefore, that the principle of ' direct action ' cannot be carried to any length, without raising the question as to the distinctive modes of expression under pleasure and under pain. Either the diffusion is the same, in degi'ee and in character, whether the primary shock be pleasmg or painful ; or there is a difference. If there is a difference, what is it ? Until this question is probed to the bottom, everjiihmg is vague. Darwin, in describing particular instances, occasionally notices the invigoration attending pleasure, and the depression and exhaustion often attending pain, notwithstanding its being a stimulus to activity. He remarks the contrast in natiu-e between the so-called exciting and the depressing states of the mind (78). ' Under the expectation of any great pleasiu'e, dogs boimd and jump about in an extravagant manner, and bai'k for joy ' (122). Monkeys tremble for fear, void their evacuations, and almost faint (146). The screams, groans, and writhings of extreme pain, are followed by profuse sweating, pallor, trembling, utter prostra- tion, or faintness (147). After excessive gi'ief," ' the ciix-ulation becomes languid ; the face pale ; the muscles flaccid ; the eyelids droop ; the head hangs on the contracted chest ; the lips, cheeks, and lower jaw sink ; the features are lengthened, the face is said to falU (178). In high spu'its, a man holds liis body erect, his head upright, and his eyes open (212). ' With all the races of men, the expression of good spirits appears to be the same ' (213). A similar strain of observations occurs in Sir Charles Bell's work on Expression. It is only under his prmciple of Antithesis that Darwin makes any attempt to generalize the contrastmg expression of pleasure and pain. Indeed, the chief examples that lend an unequivocal support to that prmciple are examples coming under the present head. I will, therefore, now review his mode of expounding that principle. ' Certain states of mmd lead to habitual movements which were primarily, or may still be, of service ; when a directly opposite state of mind is induced, there is a strong and involuntary tendency to the performance of movements of an opposite nature, though these have never been of any service.' Such is the principle of Antithesis. It is illustrated, in the first instance, by a reference to the lower animals : and the leading example is the dog, who has attained, by hereditary transmission, the attitude and actions belonging to the aggressive mood, but has no such hereditary endowment for affection and fondness ; what he does, therefore, when his affection is roused, is to reverse aU the DARWIX ON EXPRESSION. 663' aggressive movements. The movements of the cat, under the two opposing states — hostiUty and affection — are represented to have the same exact antithesis. The great example in man is the ' shrugging the shoulders ' — which is stated as the reverse, in all particulars, of the indignant and defiant attitude. The other scattered allusions to the principle of opposites are almost pure examples of the opposition of pleasure and pain. On the leading case — the opposition of rage and affection in the dog and the cat — -I offer the following remarks : — First, the contrast here is not a simple contrast of opposing states ; it represents two separate developments, each springing from its own independent circumstances, notwithstanding that, when developed, there is an antagonism betw'een the two. The simple contrast, the obverse implication, of a state of aggressive rage, is the state of collapse and dread under a still more powerful aggressor. Between the beater and the beaten there is an immediate and direct opposition : the mental condition of the one is the natural obverse of the mental condition of the other ; and the physical attitudes should show a corresponding opposi- tion. The mind of every fi<.'hting animal has passed through both phases ; as with heat and cold, the experience of both is necessary to the expe- rience of each. If we could suppose an animal that had never known fear, doubt, inferiority, the fact or the notion of being beaten, — such an animal would not have the fiilly developed consciousness of the condition of rage, indignant defiance, bellicose passion ; its encounters with resisting prey would be purely mechanical, like tearing up a root or climbing a tree. So, then, the antithesis to be examined is between angi-y superiority, and tamed or fi-ightened inferiority ; and this is sufliciently mai-ked in all the manifestations. It is, however, a pure example of the antithesis of pleasure and pain, of elation and depression, qualified by the situation of contest. In the next place, I must remark that Darwin's supposition of a state of affection arising without its physical concomitants and bor- rowing or evoking these by a conscious or unconscious reversal of the attitudes of anger, is at variance with the very first principle of the relationship of mind and body ; a principle, acknowledged by himself, although with hesitation and timidity. The development of angry passion involves with it a concomitant physical state ; the two must come together — the mental cannot subsist without the bodilv. This is true of Rage ; and it is equally true of Affection. The affectionate mood cannot exist without an express physical support ; and, as the capacity and the intensity of affection advances, so do the physical embodiments characteristic of the state. "We are not first made affectionate m our purely spiritual half, and then left to find out a suitable expression, in the best way we can ; we cannot be affectionate in any degree, without having at the same time the movement, the yearnings, the glandular effusions, for manifesting the affection. The power of expressing oiw feelings, is merely an incident of their indispensable physical support. 664 APPENDIX. Because animals from their fighting hfe contracted angry passion, with its accompanying attitudes, it does not follow that they should contract the affectionate moods ; indeed, the one must necessarily pre- clude the other. If they ever become affectionate, it is because, in certain situations, they derive gratification from acts that require them to court, cherish, and uphold others of their own kind. The necessities of subsistence make them aggressive ; love makes them fond and affec- tionate. The two interests are not a mutually-implicated couple, they are as distinct as Taste is distinct from Hearing ; their contrast or oppo- sition is shown only in their outgoings or consequences. To advert now to shrugging the shoulders, as an example of Antithesis. I cannot help remarking how in Darwin's own description there creeps out the opposition between aggressive energy and helpless- ness, — which is merely an offshoot of the great antithesis of elating and depressing passions— of pleasure and pain. The indignant energetic man holds his head erect, frowns, closes his mouth, squares his shoulders, expands his chest, clenches his fists, stiffens the muscles of his limbs : the helpless apologetic man releases all these attitudes ; his only positive exertion is the lifting of the shoulders (chiefiy one shoulder) and the turning outwards of the open hands. So far as I can venture an opinion upon the lifting of the shoulder to meet the inclining head, I would connect it with the general crouching attitude in the helpless and defence- less ; the meaning of which may be to make one part of the body cover the other parts, so as to diminish the exposed surface. Pure antithesis, in my view of it, simply releases movements, it does not originate counter movements ; these are due to some action of the will, direct or indirect, to suit a purpose. From this review of Darwin's two principles— namely. Direct action of the Nervous System, and Antithesis — it appears that he has. without explicit avowal, assumed the operation of the law that connects Pleasure with physical elation, Pain with physical depression. I hold that this law, if true, should appear at the very front of every theory of emotional expression ; and that it is true (with suitable qualifications) I believe there is abundant evidence. Indeed, if this principle is not true, there is no consistent relationship between mind and body. Pleasure and Pam are opposite states, as much as plus and minus, hot and cold, wet and dry ; the one negatives the otlier. Any person reflecting on these two facts — namely, that pleasxire and pain neutralize each other, and that they move the will in opposite ways — must admit their total contrariety. Now, if there be any harmonious principle in the union of the mental and the physical, con- trary mental states should correspond to contrary physical states. For contraries, we need only one explanation. Whatever be the physical condition corresponding to a state of pleasure, an opposite condition should correspond to pain. If pleasure is concomitant with the elation or invigoration of some vital process, pain should concur with depression DARWIN ON EXPRESSION. '665 or enfeeblement. Or, further, according to the supplementary law of Stinmlation, pleasure is the expending of nervous power from a full stock, pain is either no expenditure at all when there is abundance (ennui) or expenditure beyond the proper limits. It may be that pleasure consists in a certain manner of expenditure (not too sudden or violent) ; pain v/ill then consist in the opposite manner: we do not at present know what is the precise ditierence between a sweet and bitter taste, whereby under the same ner\ous condition, the shock of one is pleasant in all degrees, the shock of the other painful in all degrees. If we were dealing with neutral stimulants, those that merely rouse up consciousness, without either pleasure or pain, the law of Direct action (Diffusion) would be enough. But neutral stimulants of any considerable degree of intensity are not frequent ; with the neutral excitement there is usually either pleasure or pain. Hence, we can never lose sight of the need of qualifying direct nervous action by that law ; pleasure as such elevating the physical tone, pain as such depressing it. To show the various cautions that are needed in following out the Law of Direct Action, which Darwin (as well as Herbert Spencer), in my opinion, regards too exclusively, I will select a few typical cases, of pleasure and pain, such as we are all familiar with. 1. A slight shock of acute pleasure— a pleasant relish or taste, a sweet perfume, a melodiovis note, or the opening vip of the clouds to a sunny ray. The physical outburst corresponding to one of these mental stimulants is cheerful, animated, enlivening, in but a slight degree. To a young, vigorous, or demonstrative person, even a small pleasure will lead to a certain impetuosity of display ; which will be the more apparent that there is no pre-engagement of body or mind. To a quiet or feeble subject, the exhilaration will be more inward, or in the How and direction of the thoughts ; which is still an evidence of power evoked. Perhaps, the pleasure may fall on a mind already' depressed ; in which case, the effect will be lost in slightly abating the dejection. 2. A pleasure of greater magnitude and persistency — a decided accession of some acute pleasurable stimulation : such as a stirring piece of music, a noble prospect, an agreeable companion. All the language used for the first case can be applied here heightened for degree. The demonstrations will be metre powerful and persistent. In case of previous gloom, there nia^^ be power enough to restore the mean state, with or without surplus. The vigorous and robust will piit forth outward manifestations ; the less demonstrative will take on a cheerful cast of thought. 3. An occasion of multiplied and concurring pleasurable impressions — a great feast, with dainties, music, and company ; a joyful celebration. Under this, every one is roused into active displays of elated emotion ; the quietest temperaments have that inward thrill that bespeaks force profusely, and yet not exhaustingly, awakened. 4. Elation of tone gradually acquired and unaccompanied witli acute 666 APPENDIX. shocks or sensations — mere health, replenishment with food, stimulants, successes, bright hopes. Here, there may be no violent demonstrations ; only a gentle activity, an erect attitude, a disposition to converse, to love and to be loved, a readiness for exertion, as if under a refreshing stimulus. This last case opens up one aspect of voluminous or massive pleasm-e — namely, its being serene, soothing, quieting— as opposed to the rousing or stimulating pleasures, which are mostly acute. The physical side of such states may seem to be an exception to the law ; as there is a lower- ing instead of a quickening energy. Thus muscular repose and sleepi- ness, if yielded to, are massive pleasures ; yet they are accompanied with decline of energy. There is, however, no real contradiction. It is the very nature of the state to grow out of a muscular lull ; this is its basis. So far as compatible with that essential condition, the pleasure is accom- panied with its quota of enlivening accompaniments ; the reposing labom'er has a remnant of force enoiigh for a cheerful demeanour. Now for Pains : — 1. A slight smart, an acute shock — the stroke of a whip, a bitter taste, a sudden mal-odour, a screeching noise, a glare, a small disappoint- ment or failure. The shock being sudden, and the system vigorous, this is the occasion for the lively demonstration that ssems most at vari- ance with the law of Pleasure and Pain. The individual is wakened up to a very active display ; he starts from head to foot, falls into a brisk walk, gesticulates, and seems prepared for great deeds. 2. Let the shock be much greater — a more serious blow, but still acute ; and let the subject possess great physical vigour at the moment. There will still be a lively and energetic outburst, and the appearance as if the greater intensity of the shock made a proportional intensity of the diffused manifestations. This is only, however, on the supposition of a fund of vigour in the individual. Let the case be a weak or exhausted subject, and this second degree of stinmlation is the reverse of invigorat- ing, even in appearance ; it induces prostration, loss of strength, quies- cence under a pain still rankling. 3. Suppose, next, an accumulation of painful shocks at many points — a shower of missiles, a stroke with the cat-o'-nine-tails. It is only for a moment, and in a robust subject, that this more terrific infliction can be followed by active manifestations. According to the uncorrected law of Direct Action, it ought to inspire a giant's fui^y ; in point of fact, it is simply overwhelming, crushing, utterly prostrating. The delusive ap- pearance of strength, under a moderate smart, is no longer seen, even to a trifling degree. Very strong men, at the halberds, keep up energetic gesticulations for a short time ; but, although these are supposed to mitigate the agony by diverting the nervous force, they soon die away. 4. Keeping still the obverse parallel of the instances of Pleasiire, I take now the case of general mental depression, withoiit acute inflictions : as cold, hunger, fatigue, danger, defeat, mortification, remorse, despair. The physical side here is weakness, depressing enervation, without any DARWIN ON EXPRESSION. 667 redeeming circumstance, or the pretence of activity. Some special in- spiration is requisite to waken up the powers under massive depression and gloom. Our general law is seen without any distorting or misleading appearances. 5. A very special and highly ilhistrative case is the irritation of a sore, or a ' raw ' ; than which nothing is more destructive of vital energy. The tearing open of a womid, or a protracted sm'gical operation, induces fainting and sickness — the culminating term of the debilitated nervous centres. Something of the same prostration follows a blow on the more sensitive organs — the eye, the nose, the ear, the stomach, the testicle in men, the breasts in women. The properly Emotional expression, or manifestation of the Feelings, is constantly mingled with pure and proper volition ; and especially is this the case with Pain. The action of the Will is loudly demanded in acute agony, first to procure relief, and, failing that, to deaden the feeling by a diversion of nerve force to the muscles. Hence, there is probability in Darwm's view, that the expression of acute pain is, in its origin, voli- tional, or stimulated with a view to rehef. The energetic gesticulation that follows immediately on pain, not too severe, or in strong subjects, may be an inherited tendency, beginning in the ordinary coiu-se of the Will,— namely, to seek relief from pain by efforts proportional to its violence. It is in Will, or volition, that the proportionality of action to stimulus may (with certain allowances) be fairly attested. Before proceeding to Darwin's first and greatest law, the princiiale that is his crown of glory as a theorizer, I will make a passing allusion to two minor circumstances, partially adverted to by him, which enter into the explanation of our movements of expression. Tlie first is the sinaultaneous or consentaneous action of the muscles, described in the present volume (p. 288) as the law of Harmony of State of the muscular system. Yawiiing is quoted by Darwin as a good example. Again, in scratching a part that itches intolerably, there is a forcible closure of the eyelids ; which may come under that general action by which almost all the muscles of the body are made rigid at the same time. The second circumstance, which a gi'eat deal might be made of, is the Limitation and Diversion of energy. The dropping of the jaw, in astonishment, is attributed to the great draft of nervous energy in supporting the active strain peculiar to the state ; there is a relaxation of many of the muscles, the mouth opens, and the jaw drops of its weight (p. 284). The vacant expression of the eyes, in a mood of intense abstraction or meditation, is caused by the relaxation of the muscles that converge the eyes (p. 229). A very large number of situations might be pointed out, wherein the characteristic display is due to the loss of energy at one point through its absorption at another ; as stopping suddenly in 668 APPENDIX. a walk, when a thought strikes us, or when about to say something emphatic to a companion. It is under the ' Principle of Serviceable Associated Habits ' that Darwin brings to bear upon the problem of the origin of Expression, his doctrine of the Inheritance of acquired powers. He supposes tlie will to be a more primitive fact than Emotional Expression, 'at least in the various specific modes and peculiarities ; for expression, according to the law of Direct Action, would be coeval with the sentient organization. The first examples of the principle are taken from the lower animals. Dogs, before going to sleep on a hard floor, turn round and round and scratcli the floor with their fore-paws, as if to trample grass and scoop out a hollow. Many carnivorous animals, as they approach their prey, lower their heads and crouch : the meaning is partly to hide themselves, partly to prepare for a rush ; they do this when there is no real occasion. Dogs are well known to go through the form of covering their excrement, in circumstances wholly irrelevant ; a purposeless remnant of some ancient utility. Kittens, puppies, and other yoimg animals have been accustomed to push, with their fore feet, then- mothers' breasts, to make the milk flow ; they do the same against a warm soft obstacle. A horse, eager to start on a journey, paces the ground ; he adopts the same move- ment when about to be fed, and impatient for his corn. It is, perhaps, in discussing the special Emotions, that Darwin obtains the most illustrative cases of inherited expression : the best are Anger and Fear. The gestures of Anger are the inherited attitudes of a combatant or aggressor ; the sneer or snarl, which sometimes uncovers the canine teeth, reveals our animal descent. The expression of Fear is connected with the violent movements for escaping danger. I shall, however, proceed at once to his mode of accounting for the anomaly of the pained expression in the human face -the energy ]:)ut forth in frowning, and in curving the mouth by the depressor of the angle. This was the difficulty that neither Sir Charles Bell nor Miiller could explain ; and it is in plain contradiction to the law of pleasure and pain. The only suggestion that I have been able to otier is that a certain amount of contraction of the smaller muscles would more effectually relax the greater, as in crouching when the body is already disposed to collapse. If we are in a depressed condition, the renunciation of muscu- lar expenditure leaves a larger share of blood to the viscera and the veins, and contributes to ameliorate the tone of mind, which is more dependent on these organs, than on muscular exertion. Now if the relaxed muscles were large, and the relaxing muscles small and lightly moved, I think there would be some gain by the positive expenditure ; and this would be one way out of the contradiction of supposing that to Pleasure and to Pain there is equally attached the manifestation of physical energy. I have been disposed to think that this explanation would suflice as regards the forced collapse of the whole body ; I have DARWIN ON EXPRESSION. 669 never been quite satisfied of its sufficiency for tlie face. In the face, the relaxed muscles are apparently too small, and the counteracting efforts too great to yield the required release of power on the whole. I will now, therefore, review Darwin's explanation. And first as to the act of Frowning ; performed by the contraction of the small muscle between the eyebrows, opposing the large muscle of the scalp (occipito- . frontalis). The frown is primarily, and generically, an expression of pain ; all its derivative applications — in anger, displeasure, eager pursuit and determination, perplexity, deliberation and meditation —are easily traceable to this origin. Darwin has two modes of accounting for the frown. One, given also by Spencer, is the habit of shading the eyes from the sun, during very intent and anxious vision, as in scanning the horizon for an approaching enemy. Spencer puts stress specially upon the situa- tion of a combat : we know that boxers toss for the sun ; and the com- batant that has the sun in his eyes is at a great disadvantage — his only resource being to draw down the eyebrows and eyelids as a shade. We may, however, give ourselves the benefit of the wider range of situations quoted by Darwin ; extending our reference to all critical occasions what- soever, where an animal might be incommoded by too much glare. The other explanation given by Darwin is to assign a train or series of connected steps in the expression of the face, accounting for the entire circle of characteristics under pain, namely, shedding tears, frowning and curving the mouth downwards. He starts with the act of screaming, as arising under pain. The exertion of the voice in pain is, he saj'S, origin- ally voluntary, ■with a view to obtaining assistance ; and is energetic, according to the necessities of the case. By inheritance, this grows to be an expression of pain under all circumstances ; it ceases to be consciously voluntary, and becomes a properly emotional expression. The exertion of screaming being thus assumed, a number of con- sequences arise, Darwin thinks, by physiological cause and effect. Violent screaming leads to the gorging of the eyes with blood : this is a painful effort, and the will is roused to various protective or ameliorating actions. Thus, the eyeballs are compressed, and the con- gestion stemmed, by the united tension of the orbicular, corrugator, and pyramidal muscles ; all whicli we know, in point of fact, to be exerted during a fit of crying ; while, at the same time, the lachrymal glands, under the like compression, give forth a stream of tears. In this group of effects, Darwin traces out (1) frowning, (2) the expression of grief in the obliquity of the eyebrows, (3) the lifting of the upper lip, and (4) the depression of the angle of the uiouth. ' When infants scream they firmly contract the muscles round their eyes, and this draws up the upper lip ; and as they have to keep their mouths widely open, the depressor muscles running to the corners are likewise brought into strong action. This generally, but not invariably, causes a slight angular bend in the lower lip, on both sides, near the corners of the mouth. The mouth thus assumes a squarish outline. The contraction of the depressor nmscle is 670 . APPENDIX. best seen in infants when not screaming violently, aiid especially just before they begin, or when they cease to scream ' (194). Such is the explanation, iterated in various forms by Darwin, of the greatest difficulty attending emotional expression. It hinges on two assumptions. Tlie one is that screaming in pain has arisen from a vohmtary beginning, namely, tlie calling for assistance. The primitive outburst of the voice woiild be either from spontaneity or in the effusion of delight, or both together ; to ' shout for joy ' is the natural result of the primary tendencies of our being. To shout under pam is exceptional and secondaiy, and supposes a sense of some end to be gained ; the habitual employment of the scream for this end transfers it from a voluntary to a purposeless act, or an emotional expression, purely and properly so called. The other assumption is that with the violent exertion of the muscles of the lar3-nx and chest, there is a congestion of blood in the adjoining parts, namely, the features and the eyes. In the eyes the gorging is especially distressing, and would, by the law of the will, induce movements of counteraction ; these being such as compress the eyeball. The actions suited to tlie etlect comprise the whole circle of moveiuents of the features under a fit of crying ; and in the milder states of pain there would be a smaller exertion of the same parts. For example, the brow is corrugated and the angle of the mouth depressed, without either screaming or tears. The hypothesis is bold and origmal, and has the appearance of being adequate to the facts (the most doubtful point, perhaps, is the extension of the supposed influence to the depression of tlie angle of the mouth). The author, in addition to his own observations, adduces the authority of oculists and others, to confirm his view of the supposed sequence of cause and effect. There underlies, of course, the wider hypothesis of Inheritance of acquired modifications, granting which we may readily allow that the explanation is feasible and probable. A more critical and advanced physiology may find flaws, and perhaps also make good defec- tive links ; while, at the present moment, any one rejecting the hypothesis will have some difiiculty in supplying its place with one stiU more adapted to the problem to be solved. Darwin's theory of Blushing is one of the happiest suggestions in the book. He carefully surveys the facts ; ascertains when children begin to blush, what are the exact limits of blushing in the bod3', and how far the different races of mankind are liable to blush. He describes the movements and gestures of the body that accompany blushing ; and remarks that the state is usually attended with some degree of mental confusion. He inquh-es into the antecedent mental states and emotions, and enumerates as the chief, shyness, shame, and modesty ; the essential element in all being self-attention, more especially as directed to ■personal appearance, and above all to the face. To explain the origin of the effect, DARWIN ON EXPRESSION. 671 he refers to a physiological principle which has of late years been bronizht into view by various observers,— that attention closely directed to any part of the body tends to interfere with the ordinary and tonic contraction of the small arteries of that part ; so that the capillaries, in consequence, become enlarged and congested with blood. In order to establish his theory, he recites a number of the facts illustrating the debilitating effects of intense self-consciousness of the bodily processes ; but I am disposed to think that the examples adduced do not all belong to one law. I have discussed at length (p. 355) the process of acting out an idea, or the tendency of ideas, in so far as allowed, to become full realities ; as when the idea of some crime that has been perpetrated operates upon weak minds to make them repeat it. This principle embraces the influence of ideas on mesmerized patients ; it also embraces the pro- duction of the phj'sical accompaniment of a sensation, by means of the ideas strongly suggested to the mind ; as salivation at the sight of food. The consequences of the principle are sometimes beneficial or agree- able, sometimes disagreeable, according to the circumstances. The idea of something pleasmg, as a feast, is itself pleasing or exhilarating ; the actualizing of agreeable ideas is agreeable, and obversely. The problem of blushing, however, requires a painful agency ; and, if it comes imder the foregoing law, it comes imder its painful aspect. But a prior question occurs, Is the tendency to raise an idea into actuality, the same as the tendency of self-attention to debilitate the parts attended to ■? Let us examine this case by itself. I have adverted, in an Appendix Note (E), to the contrast between Objective and Subjective regards ; the one being invigorating and stimulating, the other relaxing or de- pressing. Of this, as a general fact, there can be no doubt ; although no explanation has as yet been given of it, the fact itself has been accredited bv general observation. Sir Henry Holland and other physicians have remarked that attending to the sensations of digestion impairs its power for the time ; that the process goes on better if the attention is whoUy withdrawn from it. Darwin quotes a patient of his father's who, when he felt his own pulse, found it nregular : when felt by the physician, it was perfectly regular. In these cases, however, we can hardly say that there is the carrying out of an idea uito actuality'. There maj^ be instances, where a patient has a preconceived idea about himself — that his heart is diseased, or that his digestion is bad — and by dwelling on the idea, may induce somethmg of the reality. Still that is not the same as salivating at the sight of food. It would be paralleled by salivating from thmking of the glands or the sahva. The essential point is not the having an idea, and working it out in its proper character, but the con- centrating of attention on some part of our own body or of the mind. To be thmking of self is the main fact ; and the general consequence is some debility or derangement in the functions of the part ; there is relaxation of the vaso-motor stimulus of the vessels, with local conges- 672 APPENDIX. tion, which amounts to functional weakness, if not disease. Among the records of Medicine and Pathology, more special consequences' are assigned ; but this is the general result. Sometimes, although not often, a healthy action has been attributed to the self -reflecting opera- tion ; as when the catamenial flow has been stimulated by thinking intently on the operation ; and in the influence of imaginary physic. From such instances medical men have supposed that a curative power may be found to be wrapped up in tlie influence of the imagination ; but the cases that favour this supposition turn chiefly upon a principle dift'erent from either of the two now in discussion, namely, the power of hope, belief, or sanguine anticipation — a state favourable to healthy action, on the law of Pleasure and Pain. I apprehend, therefore, that Darwin's explanation of blushing rests upon the debilitating effect of self-consciousnens. This effect can be to some extent localized ; attending strongly to the stomach, al!'ects digestion ; attending to the heart's action, disturbs the pulse. The localizing opera- tion has something to do with our ideas, but not with the a^ctualizing of an idea. As pain and derangement are the occasions of our most earnest attention to our bodily organs, the act of attending to them may possibly induce an unhealthy state of the circulation. So it is, however, that when we are in our best condition of bodily and mental vigour, our regards are objective or outward. Granting then the principle of self-consciousness as affecting the vaso- motor system, how does it apply to blushing ? Thus : When we are ^ ery much stared at by others, we are led by imitation and by solicitude to think of our face : the moment we think of it, we feel it growing warmer ; this is the weak form of blushing— the lower degree of conges- tion, blushing being the higher. In some individuals, the congestion readilj" issumes the higher degree seen in reddening, or of the blush proper. The area of the blush corresponds to the parts of the body usually exposed to the public gaze. C. — Seat of revived impressio?i>i. — p. 364. The following additional illustration, regarding the physical seat of revived impressions, is given by Wundt. ' If we look long at green light, a white surface, when we turn to it, appears red ; if we look long at red light, the white surface appears green. Thus, every picture of an external object leaves behind it an after-picture, which has the same outline as the original picture, but is seen of the complementary colour of the original. Now, a picture of the fancy leaves, though generally much less intensely, an after-picture too. If, with the eye closed, a picture of very lively colour is for a long time steadily held fixed before the fancy. SEAT OF EEVIVED IMPRESSIONS. 673 and the eye be then suddenly opened and turned upon a white surface, the picture of tlie fancy is seen upon the white ground for a short time of a colour the complement of the original. This can take place, only because the eye has been wearied by the sameness of the colour of the picture of the fancy, and needs to seek relief in its complement, just as it would do with a real coloured object before it. The experiment proves that the nervous process in both cases is identical.' Kant, also, in one of his minor works, wishing to oppose the opinion that the soul or thinking principle resides only in the brain, and in one part of it, meets the argument adduced from the feeling we have in the head in hard thinking, as follows : — ' What causes the thinking soul to be felt chiefly in the brain, is perhaps this. All thought requires the mediation of si(/ns, which may support the ideas to be aroused and give the necessary degree of clearness. Such companion signs for ou.r ideas are for the most part obtained through hearing and sight, both which senses are set in action by the impressions in the brain, since their organs lie nearest to it. If, now, the rousing of these signs, called by Descartes idere inafpridles, be properly a stimulation of the nerves to an activity resembling that which formerly brought about the sensation, the tissue of the brain in the act of thinking will fall to be affected in harmony with former impressions, and thereby become exhausted.' Here, we have a partial recognition of the theory contended for in the text. Sir W. Hamilton maintains substantially the same view in the following passages :— ' I shall terminate the consideration of Imagination proper by a speculation concerning the organ which it employs in the representation of sensible objects '. ' But ex- perience equally proves that the intercranial portion of any external organ of sense cannot be destroyed, without a certain partial abolition of the Imagination proper. For example, there are many cases recorded by medical observers of persons losing their sight, who have also lost the faculty of representing the images of visible objects. They no longer call up such objects by reminiscence, they no longer dream of them. Now, in these cases it is found that not merely the external instrument of sight — the eye — has been disorganized, but that the disorganization has extended to those parts of the brain which constitute the internal instrument of this sense, that is, the optic nerves and thalami. If the latter, the real origin of vision, remain sound, 43 674 APPENDIX. the eye alone being destroyed, the imagination of colours and forms remains as vigorous as when vision was entire.' 'But not only sensible perceptions, voluntary motions likewise are imitated in and by the imagination. I can, in imagination, represent the action of speech, the play of the muscles of the countenance, the movement of the limbs ; and, when I do this, I feel clearly that I awaken a kind of tension m the same nerves through which^ by an act of will, I can determine an overt and voluntary motion of the muscles ; nay, when the play of imagination is very lively, this external movement is actually determined ' [Metaphysics, h. 169, 274). I quote further a few sentences from Mr. Spencer's theory of Memory. ' To remember the colour red, is to have, in a weak degree, that psychical state which the presentation of the colour red produces ; to remember a motion just made by the arm, is to feel a repetition, in a faint form, of those internal states which accompanied the motion — is an incipient excitement of all those nerves whose stronger excitement was experienced during the motion ' [Psychology , p. 359). Deeper physical accomj)animents of thowjht. — It is obviously incompetent to follow further into the recesses of the brain the physical accompaniments of our ideas or thinking. A certain number of plausible conjectures may be made respecting the cerebral conditions of our mental workings — conditions not with- out important practical applications. We can compare the sensation and the idea as regards physical cost, or the nerve exhaustion attending them. First. Inferiority of the Idea to the Sensation, mentally and physically. As a general fact, this inferiority is patent and un- mistakable. It is first seen on the mental side : there being a presumption from general laws of a corresponding inferiority in the physical adjuncts. Thus it happens, that the conditions and limitations of the deterioration in the idea, as compared with the actual, can be occasionally stated in physical terms as well as in mental, and often not without advantage. It is a familiar consequence of repetition, aided by favouring circumstances, to make the Idea more and more on a par with the Sensation. It can hardly ever be entirely so, under normal or average conditions ; the nearest approach being familiarity under special susceptibility of sense, backed by extraordinary cerebral endowment. The cases of equality of the two stages are DEEPEE PHYSICAL ACCOMPANIMENTS OF THOUGHT. 075 usually abnormal, and have to be accounted for by pronounced physical manifestations, namely, excessive nervous excitement, amounting almost to disease. In short, while the nervous cost of a sensation is, so to speak, trifling, the nervous cost of an idea having all the vivacity of sensation is very high ; it may be either unusual frequency of repetition in the past or momentary excite- ment in the present. The ordinary situation, as regards the Idea compared with the Sensation, being inferiority, both the subjective diiference, and the objective or physical, admit of being tested and measured. Many illustrative instances can be referred to as showing that the idea has physical consequences and supports, of the same nature as the sensation in the actual. Several of these have been quoted in the text, and the line of observation for the purpose of the inquiry sufficiently indicated. The superior associability of impressions occurring in the actual over thoughts or ideas is very manifest, and admits of being put to experimental test. Indeed, there is no great difhculty in attaining numerical comparisons throughout this region of facts. When we are considering the Emotion in idea, we have to add new conditions, without invalidating those already assigned for intellect proper. These conditions are more properly given in treating emotion as such. Second. The Idea as favoured by Eecency. It is the very nature and necessity of our transient impressions to pass out of the conscious area of the moment, and to give place to others in succession. The conscious grasp at any one instant is a limited, measurable and statable quantity. Yet, what has passed out of consciousness for the moment has a hold and a status little inferior to the actual occupants, — equally needed for the purposes of thought, and capable of playing a part while still outside the field of view. A vast range of consequences is traceable from the connexion of the present with the series of the recent and the past. A law of relative fading has to be formulated, while conditions growing out of our retentive power have to be assigned. The play of physical conditions is notably apparent in the recovery of recent impressions under the form of ideas. It is not simply the permanent forces of retentiveness and recupei'a- tion, taken on an average in the same individual ; it is also the fluctuation in our patent physical workings — nervous and mus- cular energy, repose and exhaustion, involving of course the 676 APPENDIX. different stages of nourishment of the several organs — that we have to reckon upon, in enunciating the times and circumstances of either spontaneous or prompted recovery of what has been recently in the view. One occurrence perpetually exemplified in our experience is the recovery of a discourse or series of ideas some hours after the first reception. The interval is supposed to be occupied in the cessation of rest and other causes incidental to mere time. Probably, the brain has become refreshed in the form that favours recuperation of impressions of any sort. At all events, there comes a moment, either on the same day or on awakening the day following, when the flow of ideas comes with a spon- taneous rush, increased of course by positive encouragement or absence of rival trains. The whole causation in the case would seem to be purely physical, and, as such, statable in terms of the physical. A first recovery of any consecutive whole of a train of ideas may be followed by another and another at varying intervals. All this is preparatory to the stage of subsidence and permanent memory, in accordance with the depth of the impressions of the actual in the first instance, and the ideal repetitions that circum- stances have permitted or induced. The practical fact as regards education is, that time and space should be allowed for these spontaneous ideal recoveries. When an impression in actuality, as in reading, listening, or thinking, has possessed a certain amount of intensity, there is a natural persistence or repetition, without any break ; even the indulgence of this, if without voluntary forcing, paves the way to the nervous rest that brings the subsidence. Then, after a longer or shorter time, the recollection will assert itself, as in the manner above described. D. — The Prese^itation-Continnum. The doctrine that regards our mental growths as made up of ultimate sensations united by Association, is opposed by another view, which lays the chief stress on the differentiation of a primi- tive homogeneous continuity. It is admitted that, in the end, we become possessed of a stock of associable elements, and, out of these, go on building up all our higher attainments. Yet, before we can ask — How do isolated sensation-atoms combine to form a mind ? we have to ask — How does demarcation and partition grow up within a distinctionless unity ? This, in fact, is the problem THE DOCTRINE OF THE CONTINUUM. 677 of evolution on the great scale throughout the animal series. The question for Psychology, however, is narrowed to the start of the human individual. How far has demarcation already gone with the infant at birth, and what remains to be effected by the same method — that is to say, by differentiating the homogeneous so as to convert it into the heterogeneous ; or, in other words, by making what was uniform, various, or what was simple, complex ? Evolution is most fully brought home to our minds by the supposition that, at the first start of animal life, there were no distinctive organs, but a homogeneous tissue which, by successive stages, became differentiated and developed into the higher com- plications of organized life. Out of the one uniform sensitive tissue — the single organ of touch, came all our five senses, by a long succession of stages. To this process, there are various designations. One is — the resolving of a continuum into a series of discrete and distinguish- able parts. Others are — the conversion of the uniform into the various, the differentiating of the homogeneous, and so on. We must not lose sight of the enormous physical transforma- tions in the course of evolution, whereby one of the higher animals comes into the W'Orld, with an apparatus of the utmost complicacy at all points, including a plurality of Senses, several hundred separate Muscles, and a highly- endowed Brain. As these are, by pre-eminence, the organs of mind, the mental endowments at birth are correspondingly rich and abundant. The doctrine of the Continuum, as a psychological doctrine, supposes that the infant must begin life with a nearly homo- geneous consciousness, and, by degrees, attain to the varieties that are familiar to our experience. But now, inasmuch as all the sense-organs are matured at birth, and the brain almost equally so, it is hard to believe that these do not operate to give distinct sensations from the very beginning. Allowing a few hours, or perhaps days, for the system to get into working order, w^e can give no reason why a sound and a sight should not be as distinct in the consciousness as ever they become ; while, with the sense of sight nearly mature, the spectrum may be distinguishable through all but its nicer gradations. The infant consciousness would seem to be anything but a continuum as supposed. There is no analogy between evolution in its whole extent, from a jelly- fish to a man, and evolution as merely filling out the capability 678 APPENDIX. of the human subject, all whose organs are, to a large extent, completed at the moment of birth. The only matter of fact at the basis of the continuum that I can see is, that a considerable progress is made in the delicacy of sense discrimination, from birth to maturity. How much this amounts to has never been precisely stated. Very little study has hitherto been bestowed on this part of our education ; nor has any special mode of quickening it been devised. The prominent instances are seen in the training of artisans and artists in special arts. The eye is cultivated in the form of increasing the dis- crimination of shades of colour ; the ear for sound. We have no reason to suppose that this operation can be carried very far ; and the only known method of procedure is to strain the power of attention. Great original defects are known to be incuraiDle : colour-blindness is a ' continuum ' that cannot be differentiated ; a bad or indifferent ear for pitch is insusceptible of being forced. Still less felicitous is the employment of the term to the arti- ficial products of association, or the union of discrete' elements into new trains : as in speaking of an ideational continuum. For this verbal combination, there is absolutely no necessity, and, what is worse, no propriety. When a flow of ideas is connected, by association, the result can be expressed as a succession, a series, a train, a chain, a concatenation : all which preserve the double circumstance — discreteness in the members and adhesiveness in the compound. A ' continuum ' overstates the flow^ and sinks the discreteness. Continuity is at its best when there is little or no conscious transition from one part to another, no sense of joinings of distinct members. Within each separate sense, there is a continuity in the accep- tation of a homogeneous basis — a generic quality, with specific variations of mode. The spectrum has optical homogeneity ; the musical scale is homogeneous in regard to sound. This circum- stance, however, does not even favour acquisition within the same sense ; any advantage that might arise from a common ground of sensation, is counterbalanced by another circumstance, namely, that the transition from one sense to another is accompanied with a greater mental shock, the effect of which is to add to the impressiveness of the coupling. My conclusion is that the term ' continuum ' serves no good purpose, but rather the contrary. ASSOCIATION AND DISSOCIATION. 679 Contii/uous Assoa'atioyi in the ideas of JVafural Objects. — A some- what similar vein of criticism to the foregoing was adopted by a critic in the National Review (Dr. James Martineauj, who repre- sented ' this order of derivation, making our objective knowledge begin with pUirality and arrive at unity,' as ' a complete inversion of our Psychological history '. He contends, in opposition to the explanations in the text, ' that each state of consciousness, whether awakened through more or fewer channels, is, during its continu- ance, originally simple, and resolves itself only by change of equilibrium '. ' Experience proceeds, and intellect is trained, not by Association, but by Dissociation, not by reduction of pluralities of impression into one, but by the opening out of one into many.' The supposed influence of dissociation is an unquestionable fact, but represents a different phase in our intellectual opera- tions, and is no ways incompatible with the view given in the text of the workings of association. Indeed, to deny association, as I have represented it, is to cripple and maim the habitual operations of our intelligence. It must be admitted, as the reviewer remarks, that the first presentation to consciousness of an object, afterwards accounted complex, may not necessarily give a feeling of complexity. It may be that the effect of any new presentation begins with an indefinable shock — a rousing of consciousness, through mere change of impression. Such consciousness need not be styled either single or complex ; it may be better considered as purely vague. If we could treat any impression as an absolute novelty, that is, if we were placing ourselves at the positive commencement of our mental history — a purely speculative supposition, seeing that that history does not properly commence with our birth — we should have to regard that presentation as indefinable and incom- plete, until it had disappeared and reappeared with sense of agreement with itself and difference from intervening impressions ; out of all which would be evolved the definite characteristics that we finally place on our mental record. The ordinary process of Dissociation in our familiar experi- ence, by which we resolve a complex into its elements, may be taken as one application of the law of Similarity. Our habitual position, as regards the objects falHng under our cognition, is that every one of these complexes has, in the past, any number of resemblances. Setting aside cases of absolute identity, the kind of resemblance that we have to take into account is partial. The 680 APPENDIX. round figure of a pebble revives the accumulated impressiou made by all experiences of roundness : the colour is fused with all the previous impressions of that colour ; the hardness brings back the sum total of traces of the same hardness, and so on. Hence, Spencer justly describes perception as a process of da'idfiejdwn. As a compositor distributing types effectually disintegrates his compound impression of a word, by tossing an (i with the n%, and an n with the 7^'s, so we require a foregone reference for each item of a compound sensation ; but, when this has been obtained by means of our growing stock of agreeing impressions, we are prepared for the work of combining and associating in the manner explained in the text. E. — S'uhjedive studies kikI feiiardt. — p. 467. The Objective direction of the mind implies the exercise of the seyines upon the various properties of the Object world, with the least degree of attention even to the pleasures and pains growing out of this exercise. Extension, Form, Colour, Sound, and the chief Tactile properties, belong to our objective attitude. They cannot be taken cognizance of in an absolute void of sub- jective regards, since the motives to attention are, in the last resort, feelings, — that is, elements of the Subject. In the inferior, and more exclusively emotional, senses, — Smell, Taste, Organic Life, — subjectivity is more developed, and attains its maximum in the Organic sensations. The Object attitude further includes reflexion on object pro- perties, — as when the geometer studies a problem mentally, or an engineer meditates his plans before putting them on paper. In these situations, the mind is conversant with subject elements, in the form of ideas ; but it thinks of these ideas as representing object realities — it does not make a study (as a psychologist would do) of the successions of ideas as exemplifying mental laws. The study of the sciences of the so-called External, or the Object, world, is purely an object attitude. In none of them is it absolutely necessary to be subjectively engaged. In the practical science named Logic, maxims may indeed be derived from the study of mind; in Ethics, this is so to a still greater degree : but, to that extent. Logic and Ethics are conversant with the subject mind. OBJECTIVE AND SUBJECTIVE CONTRASTED. 681 The various practical arts and operations conversant with object properties (Agriculture, Manufactures, Navigation, etc.) evoke the object regards by almost exclusive preference. Except in the motive (the p.nd of Ainstotle), which must be in the last resort some feeling — pleasure or pain, — such arts do not strictly involve in their machinery anything introspective. The exception to the rule will be noticed presently. Even as regards the mind itself, our knowledge is not neces- sarily, or wholly, subjective. It nuist be so in part ; but, as every mental fact has a physical counterpart, and every mental sequence runs side by side with a physical sequence, we may, and often do, remain content with the physical aspect, and may image the phenomena to ourselves under that aspect exclusively. Such is the form wherein we embody our knowledge of the in- ferior animals : we make little or no attempt to penetrate into their consciousness ; perhaps, when they give evidence of acute pain, or acute pleasure, we have a certain subjective sympathy with those states ; but we think of their characteristics mainly under the objective manifestations — their likings and dislikings are imaged under a variety of movements and bodily configura- tions, like a spinning jenny or the working of a ship. The same may be said of children. In nearly the same exclusively objective forms, we can study, and think of, our grown-up fellow-men. We may refrain from conceiving their pleasures, pains, emotions, ideas, in the subjec- tive character ; we may think of them all, through the allied object appearances — such objective circumstances as material abundance or material privation, and the objective displays in action, gesture, and language, in symptoms of health or disease, life or death. We may even maintain a certain propriety of conduct towards our fellows, while considering their interests solely on the objective side. There is comparatively greater pre- cision and certainty in dealing with this outward side : our senses can teU us whether any one has had an average meal, or the usual amount of clothing ; and whether the person has a satisfied cheer- ful look, or very much the reverse. The practical management of. human beings may be conducted (not badly) on the same objective method. A military connnander may image or conceive his army purely as a fighting engine, re- quiring material supports, and displaying itself to the eye of sense by marching and fighting, and by outward expressions of con- 682 APPENDIX. tentment or displeasure. He may never conceive their proper feelings at all ; perhaps, he is too exclusively bent upon object regards, to be often aware of his own. Nevertheless, the knowledge of beings endowed with mind is not complete, not thorough, without, to some extent, coupling the subject study with the object study : as will be seen when we consider the precise nature and results of a subjective reference. (1) We are in a subject state, if we are under Feeling, as when alive to pleasure and pain. It is finally on account of these that we exist ; for these we are prompted to objective exercises and regards. Yet in the moments when the object attitude is trium- phant, the feelings that induced it are under an eclipse ; we have to remit the object strain, at intervals, to allow either pleasure or pain to be felt or to come into consciousness. Now, as human beings rarely exist in the exact mean in anything, there may be an excessive tendency to the object attitude, brought about chiefly by great spontaneous activity, and by the predominance of the object senses — sight, touch, and hearing ; whence, too little space IS given to the subjective expansion even of moods of pleasure. The tracts of objective indifferentism may encroach upon our positive enjoyments, since these demand a certain frequency of relapses into the subject attitude. Subjectivity enlarges the area of feeling, both pleasurable and painful : to our gain, if pleasure is the ascendant fact ; to our loss, if pain predominates. (2) The Subjective attention is necessary to the recollection of our pleasures and pains, as such, or on their purely mental side, the side wherein lies their power as motives. The object side of pleasure and pain^the outward means of procuring the one or avoiding the other — has a motive force, but only by association wdth the subject fact ; and it needs to be re-invigorated and cor- rected by consulting the subject experience. The subjective study is the only way of estimating things at their real worth ; it teaches exactly what every agency does for us in the final appeal. Not to bestow this amount of study is to leave ourselves at the mercy of irrational fixed ideas, — as wealth or the contempt of wealth, honour, power, affection, length of life, and other things. Sub- jectivity contains the part of the philosophic habit that has regard to the intrinsic value of each worldly good, which is the measured subjective value, ascertained by self-consciousness, and by an accurate memory and comparison of experienced pleasures and pains. CASES FOR SUBJECTIVE ATTENTION. 683 Thus, although without Subjectivity man may be tolerably careful of the usual outward aids and adjuncts to happiness, it is yet indispensable to the higliest development of Prudence. It is also, to the same extent, favourable to the fullest and truest forms of Sympathy, or to the appreciation of the exact conscious experi- ence of others, as distinguished from their outward circumstances and manifestations. (3) The subjective tendency is also necessary to the delicate sense of right and wrong. Ethical self-examination, to be thorough, must be conscious, having regard to the feelings, motives, or intentions of the actor. It may not, however, be essential to rectitude in all degrees, but only to the highest degrees. The Stoical morality, as seen in Marcus Aurelius, was intensely subjective ; so also is the highest morality of the modern world. The best practical mode of seizing the ideal balance of the objective and subjective regards, is, in the manner of Aristotle, to study the extremes. The Objective regards have these signal advantages. They are favourable to activity ; they promote health ; they subdue both a considerable amount of pain, and also morbid broodings and discontents. They alternate the outbursts of pleasure with large periods of satisfied indifference ; thereby enhancing enjoy- ments when they come. The delineation of Plot-Interest is the illustration of these advantages. The disadvantages of too great Objectivity are expressed by the negation of what has been said in favour of the subjective regards. The disadvantages of excessive Subjectivity are also implicated in the above remarks. Explicitly, they may be described as an inactive, unhealthy, morbid preying upon self ; an aggravation of painful states generally ; an extreme occupation of mind with organic feelings, called hypochondria ; a tendency to push ethical self-examination to the point where it brings misery rather than a stimulus to duty ; a my sticizing disposition to convert subjective abstractions — as soul, will, conscience — into independent exist- ences; an extreme idealism, with a distaste for the practical world as it is ; a susceptibility to opposition and to reproach ; a revulsion against the coarse, indiscriminate energy of the objec- tive man. Self-consciovisness varies with the condition of the individual 684 APPENDIX. as regards health and vigour and also age. The robust frame is naturally objective ; states of exhaustion, bodily depression, feeble health, pain or discomfort — favour the self-conscious attitude. Youth is objective ; the tendency of advancing age is to promote subjectivity. The ancient world, compared w^ith the modern, was objective. Homer, as a poet, was in the objective extreme ; Wordsworth is near the other extreme. Shakespeare has strong subjective leanings ; but, in him, there is a good mixture of both. The excess of subjectivity^ is seen in the religious mystics. An admirable example is introduced by Goethe, into Wilhelm Meisfer, under the title ' Confessions of a Fair Saint '. Adam Smith's Theonj of Moral Se.ntiments is a continuous subjective exposition ; his language and illustration preponderate towards subjectivity. (4) The study of the mind, as a science, must contain an element of introspection. Tbere is difference of opinion as to what ratio this should bear to the objective study of the physical concomitants of the mind. Some psychologists define the science of mind, as the science of the facts of Consciousness, meaning Self-consciousness or subjectivity ; as, for example, Hamilton and Cousin. Auguste Comte, in his Coiirs de Pliilosophie Positice, rejected self-consciousness as a source of mental knowledge, and proposed an exclusive reference to the material adjuncts, as exhibited in the Physiology of the brain. The only tenable position is the combination of both. F. — The Abstractions — Number, Space, Time, Self. In the great controversy as to whether our entire knowledge is derived from experience, or whether part of it is derived from an ivtaitive source, the supporters of the last-named view have given various enumerations of the elements declared to be intui- tive or innate. Those elements are stated either in the shape of Notions — as Time, Space, Cause, or in the shape of Frinciples — as the axioms of Mathematics, and the law of Causation In point of fact, however, the same intuition is -given sometimes as a notion, and sometimes as a principle. Thus, the intuition of space is considered identical with the intuition of the geometrical axioms. The notion ' cause,' and the law of cause and effect, must be treated as the same thing in a different form of speech. ATTRIBUTE OF QUANTITY AND NUMBER. 685 For example, Mansel's enumeration of innate elements (exclu- sive of the moral sentiment) would probably be exhausted by the notions — Time, Space, Cause, Substance, together with the principle'^ of Identity, Contradiction, and Excluded Middle (called the Laws of Thought). Each of the notions could at will be ex- pressed in the form of principles. It is sometimes said, that the axioms of Geometry flow out of, or are derived from, the notion of Space ; but, more correctly, the notion and the axioms are to be held as the same intuition in an altered dress. Number. Of all the attributes of things knowable to us, the most comprehensive and widely spread is Quantity. We cannot be conscious at all without the consciousness of more or less— of degree, or quantity. Our very first acts of discrimination and of identification have a certain reference to the degree of our feelings : of two differing sensations of light, one is felt as more intense than the other ; of two muscular energies, we recognize the difference of amount. It is the same with pleasures and pains, and with less intellectual feelings generally. The property called ' degree ' is inseparable alike from object states and from subject states. We even discriminate different modes of degree : we distinguish the fact of continuance from the fact of intencitij, and estimate the degree of each by comparison with its own kind ; one day is longer than another ; one flame is brighter than another. Our estimate of degree is more or less delicate according to the quality of the sense concerned. In the higher senses — sight and hearing, — our discrimination is at the maximum — as in the interesting case of visible, or retinal, magnitude. Quantity, or degree, is familiarly divided into two kinds — rontinuoux and discrete. Continuous, or unbroken quantity, is the more typical form. Its best example is the Duration of a continuous impression — the continuance of a muscular exertion, a sound, a pleasure. It further applies to Extension, whose primary measure is the con- tinuance or duration of movement. It does not apply to intensive quantity, or the comparison between a stronger and a weaker impression, — as the loudness of a sound, or the brilliancy of a light. Discrete quantity is the same as number. It supposes our im- pressions to be interrupted, or changed ; and takes advantage of 686 APPENDIX. the effect of sudden change in making us acutely conscious, or mentally wakeful. In the case of breaks, or interruptions, we note the frequencij of the transitions ; we mark the difference be- tween a transition made once, and a series of those transitions — two, three, four, and so on. This is Number. It is in various ways a remarkable experience. In the first place, it is given by every sensibility that we possess. By Aristotle, it was accounted one of the common perceivables, or the notions attained through all our senses alike, — w^hich is true, but not the whole truth. We have it by every one of our emotions ; we distinguish a day when we had one surprise, one fright, one fit of anger, or one burst of tender feeling, from a day when we had two or three such experiences. We have it from the fiow of our ideas, which are interrupted or discrete effects. In the second place, Number is our best and most accurate means of expressing quaiitity. The most delicate of our sensi- bilities — visible magnitude — may be to some degree inaccurate : two persons may differ as to whether two rods exactly coincide in length ; but nobod}^ was ever mistaken in the difference be- tween one and two. Hence, the highest art of measuring both continuous quantity and intensive quantity, consists in resolving each into discrete quantity ; the beats of a clock are a surer measure of time than the place of the hands between the dial figures. Probably no one now contends that Number as such is an intuition, or a ' form of thought,' provided by nature beforehand. It is a fact inseparable from the nature of our feelings : if these are intermitted and resumed, they are, by that very circumstance, numbered ; and if our consciousness is interrupted by beats, or transitions, it is a consciousness of number. Space. The origin of our notion of the Extended, — the charac- teristic property of the object world, has been already traced in its successive stages, under the heads of Muscular Feeling (p. 96), Touch (p. 198), Sight (p. 254), External Perception (p. 387). If we accept the inference formerly drawn (see p. 330) from the precocious reading of Emotional Expression in infancy, and from the instinctive aptitudes of the lower animals — that inference being that space relations, in all the three dimensions, are embodied in us at birth, to be unfolded and perfected, but not created, by •experience and education, — the problem of the origin of space ORIGIN OF THE NOTION OF SPACE. 687 must take an entirely new departure. The controversy between the Kantian and the Lockian, or experience, school, as to the priority of forms of thought to any concrete experience, is trans- ferred to a higher plane. When we accept the rendering of Instinct by Hereditary Experience, we must pursue backwards, in tlie animal succession, every aptitude that is not obviously gene- rated by our life experience. The derivation of our notions of Space, or of whatever may be our mental position at birth as con- tributing to such notions, must be carried backwards in the animal development to a point where we can gratify our curiosity only by plausible hypotheses, grounded on knowledge of actual intellectual workings. What then have we to proceed upon in such a speculative re- trospect ? The answer is, that the notion of Space in the concrete is a composite notion ; its analysis is rendered possible by our consciousness, by which we can trace, in the compound, a number of elements that we regard as simple. These elements are of course the sensations of our senses, more especially Sight and Touch, coupled with our Muscular Sensibility. A certain amount of controveisy still adheres to this analysis. For one thing, it is questioned, whether the muscular feelings are an essential in- gredient in the idea. For another thing, it is alleged that the notion is partly or wholly made up of those sensible feelings, that have the character of massiveness, through extent of superficial contact. The tendency with recent authorities, seems to be to combine a certain amount of nmscular feeling with the sensations possessing mass or extensity. There is no other w^ay of settling this than by an appeal to our present consciousness. If it is admitted, as already contended (see p. 389), that the very meaning, import, or essence of extension, is scope for movement, then our muscular sensibility, by which movement is cognized, is the veritable groundwork of the notion, aided, it is true, by a number of sensible experiences which bring out into relief the muscular fact. It can only be a matter of individual opinion, that extensity in sensation is a co- operating factor. We know that such extensity or mass of sensation is now to us a sign, measure, or criterion of extension — an effect that would necessarily be produced by long association ; but we do not know, and never shall know, whether in the first commencement of that notion in the animal series, extensive or massive sensation was the groundwork, in whole or in part, of what we are now con- scious of as tri-dimensional space. 688 APPENDIX. The whole speculation as to the origin and upbuilding of our conception of Space would have to follow the manifested powers .at birth of the animal series through all its successive gradations. Supposing it first started in some remote ancestry of sentient beings, it would seem to have been variously modified in the dif- ferent tribes, according to their peculiar circumstances. It most manifestly attained a perfect working pitch in all such creatures as, at the instant of birth, can make their own way and provide for themselves in their special environment ; that environment being of course the three dimensions of space, occupied with material suited to their wants. No doubt a considerable amount of our own early education consists in advancing to perfection our familiarity with the outer world in its space relations. Moreover, our knowledge of space, in its highest consummation, contains a number of artificial notions belonging to a late civilization, — by which we deal with it in all its aspects, measure its amount, multiply, divide, and sub- divide its contents for our various purposes. Careful researches into infant development may do something to assign the comparative shares of Instinct and Experience, in this vast endowment. Our inquiries have gone far enough to make certain, that life experience cannot account for it. We may further dismiss as a pure irrelevance and waste of words the much-debated issue connected with the familiar designation ' Forms of Thought '. "O" Thne. This is one of the intuitive ' forms ' of the a priori school. The Experience Psychology treats it as an abstraction from 'particulars. In our feeling of the continuous, whether in movement, in sensation, in emotion, or in intellectual strain, we have a consciousness of degree, and that consciousness is the fact called Time or Duration. Time, in the abstract, is the generali- zation of all these modes of the continuous, and apart from these, or prior to these, it does not exist. We cannot be conscious of two movements being differently prolonged, — as, for example, lifting (at the same pace) a weight one foot and lifting it two feet — without having a particular experience of duration ; we could not be deprived of that cognition, without being deprived of one phase of our discriminative muscular sensibility. Should this be so, a form of thought pre-existing in the mind, corre- sponding to Time, is a superfluity : it could add nothing to our OEIGIN OF THE NOTION OF TIME. 689' particular experiences of duration ; and our generalizing faculty can obtain, out of these, whatever is nieant by Time in general, or in the abstract. While we have thus a sufficient basis for estimating degree, in the endurance of our conscious states, a certain clearance is supposed to be requisite in order to evolve all that is meant by Time. Just as Space, when fully developed, comprises the world of objective existence, viewed as a contemporaneous whole, so Time is the great complementary abstraction necessary to assign the phases of succession that make up the great stream of causation or production, identified with the interests of living humanity. There might l^e consciousness of duration of Subject states out of relation to the rigid, predictable, and causal suc- cession of outward events. Our flights of imagination have their continuity and conscious measurement, without being represen- tative of Time, as an Object fact. The Succession that we are in quest of, and have to account for, is the transition of a past that has been present into a now present, to be continued into a yet future. It will thus be obvious that the Time notion carries with it certain elements beyond the sphere of pure Intellect. In particular, it has reference to the state called Belief, as applied both to the Past and to the Future. As regards the Past, it contains the reliance upon the former reality of something persisting as an idea. It discriminates among our present ideas the representa- tives of former reality from those that have no such representation. As regards the Future, we need to distinguish between present ideas that are to become realities and those that are not. In this enlarged conception of Time, we are supposed to be able to extricate a real past, a real present, and a real future from the promiscuous flow of our ideas as determined by the intellectual forces and chance presentations of our ditferent senses. The elementary situation is assumed to be a sensation that has just occurred in the actual, and has given place to another now in the actual. Both the idea of the past, and the sensation of the present, are coupled in the consciousness of the moment. With the ideal element, we have inseparably combined the consciousness that it was an instant ago an actual, like the present actual. Its faintness, its unsteadiness of hold, are its marks as an idea ; and its distinction from what is now the actual, namely, the present sensation. We may suppose the moon before us in full vision ; 44 '690 APPENDIX. this is a sensation, in other words, an actuahty. In an instant, a cloud passes and obscures it. The actuahty now is the visible cloud and the diminished luminosity accompanying the obscura- tion. The previous actuality — that is, the unclouded moon in its full presence — has become an idea ; it co-exists with the new reality, the visible image of the cloud. This is the conscious situation, when we combine in our view a present and a past. The persisting representation of the moon in such a conjunction is what we rely upon for treating it as a veritable past. The legends of former ages have been described as a past that never was present. They are separated from reality or actuality by a chasm that cannot be bridged. The past that was once present has an ideal continuity with the actual present, every step of which must have brought an ideal and an actual into the same moment of consciousness. Our varied experience of successions — object and subject — has been seen to leave in the memory an enormous deposit of intellectual products available for the purposes of life. We have further acquired an immense representative machinery for express- ing succession as a measurable fact. Both of these acquisitions apparently may be accounted for by our conscious life experience. Now, as we have seen that space, in any view of it, needs a very large contribution from our supposed hereditary experience, it falls to us to ask whether the notions of time and succession that we trace in ourselves, as far back as memory can carry us, are more matured than the intellectual growth of previous years can account for. At first blush, it would seem that time and succession are much less complicated in their nature than Space in its three dimensions. Supposing we come into the world with a prepara- tion for conceiving Space, — is there any assignable preparation necessary for beginning our education in Time in order to the maturity that it possesses in oin: fourth year ? The answer to this question is by no means easy. It needs a precise determi- nation of what the time notion amounts to, in our earliest con- scious years. Possibly, if we could analyze it fully, it might depend upon our space notion, as a part, and upon elements of succession that we could not arrive at without some instinctive commence- ment. Nevertheless, to state what that instinctive commence- ment might be, is probably a task too subtle for our present resources. We should not only have to strip off all the artificial machinery of time measurement — years, months, days, hours, SELF OR THE EGO. 691 minutes, etc. — but some perceptions in advance of all these, viz. — the sequence of visible events around us, having their embodi- ment in modes of Extension, coupled with belief in the past and reliance in the future. How to arrive at the reality of past, pre- sent, and future, for our most familiar and pressing needs, and what groundwork of an instinctive kind would be involved therein, it would w^ith our present knowledge be too venturesome to pro- nounce. All that we could say with safety is, that the gift of heredity or hereditary transmission may apply to one notion as well as to the other ; and that something may be gained, from the experience of former generations, in aid of the jsrimordial ingredients of our sense of real succession. We have found the observation of the inferior animals to be of use in confirming the intuitive character of Space. We have had to regard the aptitudes of a quadruped or a bird w^ithin a few hours or days of birth, to be entirely beyond the scope of ex- perience or education. This is as regards Space. We may now put the question — ^Is there anything in those aptitudes that implies a cognition of the essentials of Time ? The sheep soon attains a notion of its surroundings in space — of the near and the far, the right and the left. Is there any further implication in its doings of the nature of Time-succession ? Apparently there nuist be. There is at least some experience of causation, and a dis- position at the first glance to proceed upon it in the operations of self -maintenance . Anyhow, the hypothesis of a pre-existing form of thought for Time would seem as little adapted to the problem viewed in the light of heredity, as it is to the still vaster accomplishment of entering upon tri-dimensional space. Another discussion, attached to the problem of Time, relates to our feeling of a series of events as rapid or as slow, the actual duration being the same. An hour's duration, according to the events that it contains, and the state of our feelings, may seem much longer or much shorter than the actual hour. The causes of this variation of estimate of the same period of time are an interesting study in themselves, but have only an incidental bearing upon the main problem of the origin and growth of our notion of time-succession (see Hoffding, Psijchology, English translation, p. 188). Self — The Ego — PersonaUtij. As a problem of geiipsis, the topic 69'i APPENDIX. indicated by these names has to be cleared of a number of ques- tions given under the same titles when fully expressed by help of their completing contrasts, namely, self, not-self ; subject, object ; ego, non-ego ; personal, impersonal. Here, as with the other great fundamental notions or abstrac- tions, we need to modify our rendering of growth or development by the fact of inheritance from the past. The stages whereby the child is supposed to reach the mature notion of Self, the Ego, may be correctly set forth in the order of sequence or develop- ment, and may yet require a retrospective reference, instead of being limited to the individual lifetime. If Space, as conceived at the earliest moment that we are able to read mental history, be an acquirement much beyond the education resources of the individual, so may be the distinction of Self and Not-self, however correctly we may assign the steps in the building up of the distinction. This observation does not interfere with our attempts to render an account of the process ; it only shows that there is, in all probability, something entirely inscrutable in the absolutely primitive start. The assumption that space or extension is a mental possession, whether as fully realized or as largely prepared for, would, as a matter of necessity, be a step towards the distinction of Self and Not-self. Indeed, we may say that the clear consciousness of Extension would carry us as far back in mental history as any acquirement that can be named. We are utterly at sea in any attempt to describe the earliest dawn of the notion, and, perhaps, equally so in endeavouring to imagine its necessary implications or accompaniments. Eeverting to the various allied issues that have come before us, in our review of the mental forces concerned in our psychical development, we find the following : — (1) The Definition of Mind proper. In conducting this inquiry, we were content to take Mind in its commonly recognized workings, and to say nothing as to the steps whereby we have arrived at our mature conception of its nature. This carries us back to our introductory start in the present work. (2) The analysis of Subject and Object', with a view to show which of the constituents of our mental experience or conscious- ness are aggregated round each. For thig problem also, we are satisfied to deal with mature states or conditions of mind, and think it unnecessary to go back to the genesis or history of these. GENESIS OF THE NOTION OF SELF. 693 In short, we do not make it a research into origins or educational development. (3) The distinction of Subject and Object regards, — the alter- nate engrossment of the present consciousness with one or other respectively, the circumstances that make either predominate for the time, — make up a theme both interesting in a speculative point of view, and important in its practical bearings. This has been sufficiently handled both in the text, and in the supple- mentary note (E) immediately preceding. This topic also is devoid of reference to the origin of our cognition of the Ego or Self, as an organic growth. (4) Mind and Body, in their ordinary contrast, do not precisely coincide with any one of these three coupled designations. ^ Mind no doubt still means the subject, as in the first and second issues ; but the name Body is limited to our corporeal framework, and lays stress upon that as an organic unity, special to the individual. The contrast of Self and Not-self, where the Not-self means other living and conscious beings, may also be introduced as an alternative issue ; but is more intimately involved than perhaps any of the others with the question that we have to'handle. On setting aside these various leading issues, with a view to isolate the problem immediately in hand, which, however, may incidentally require their aid, and further on refusing to limit the search for an origin to the individual life, we may state the question to be : — What are the ultimate elements of mental experi- ence that lend themselves to the growth of the great aggregate termed the consciousness of Self, and what is the order of time in their respective contributions ? Among those psychologists that have directed their attention to this special department of inquiry, there is a certain concurrence, both as regards the constituents of the notion, and as to the succession of the strata deposited during its growth. It is by f>n attentive study of infant development that we bring the topic before us within the reach of definite cognizance. Althovigh this development may involve inscrutable preparatory antecedents, yet we must be content with stating the order of dependence and sequence in terms of the infant manifestations. In Professor Sully's exhaustive assignment of early impressions contributing to the final aggregation of self as a product, promi- nence is given to the following circumstances : — For one thing, the child may be supposed to take cognizance of its own body, partly 694 - APPENDIX. as a visible object distinct from other visible objects, partly as giving birth to a variety of sensations in conjunction w^ith its visible aspects, and more especially its movements. This is a portion of the process needed for the subject and object distinction in tbe foregoing meanings (1) and (2). Again, stress is laid more particularly upon the Organic Sen- sations as being an almost initial element in our cognition of self. The organic pleasures and pains force themselves into conscious- ness, and are in obvious contrast to other forms of sense con- sciousness, as sights, sounds, and touches ; they are truly and unmistakably states of the Ego from first to last. They may well be supposed to have priority, when we compare their standing with the other contributory mental experiences next to be men- tioned. The power of putting forth action to a wish or an end, thereby getting rid of some pain or attaining some gfatification, is an additional phase of the child's being, which when taken notice of, would be distinguished as object sensation and readily unite with organic feelings. The consciousness of Self as an active being would start from such elementary efforts. We may very readily mistake the date of maturity of this addition to the earlier con- sciousness of pure organic sensation, but, sooner or later, it will fall into the growing aggregate. That Ideation as opposed to Sensation is a constituent in our cognition of the totality of mind is admitted at all points. The exact moment and circumstances of its appearing in the child consciousness may not be assigned with any precision ; but, from the nature of the case, it may be surmised to be of later maturity than the previously named constituents. To contrast Imagining with Perceiving is merely a variety or consequence. The relations of the child to those about it, of which one of the many incidents is the use of language, as in distinguishing the personal pronouns, makes the child aware of itself — bodily and mental — as a separate entity or personality, resembling other per- sonalities, but yet separated from them. When the child begins to use language on its own account, its progress is no longer sub- ject to ambiguity : the stages are all manifest to observation. We can then confirm the hypothetical surmises as to the first stages, and trace out those that remain to be accomplished. What view the child takes of the inner self, as distinct from the bodily self, and how this view becomes gradually modified, may PERSONALITY. 695 be discovered by attentive observation in each individual case. There must be great personal differences in these respects, and the influence of others, in suggesting and shaping the result, will be the tinal determining element, and will be easily known. We must go far beyond infancy in order to see the matured and com- pleted aggregation, such as it happens to be. Illusions have to be dispelled, and distinctions drawn that require both maturity of years and special education, or natural power of intelligence. Eetrospective memory, with its power of ordering ideas in chronological sequence, makes up what is known as Personal Identity. This covers both the mental and the bodily history, including at the same time such outward surroundings as give aid to the coherence and fulness to the contents. The combined bodily and mental self is what we most easily conceive and retain. It is on rare occasions, and for special purposes, that we regard the mind as distinguished from the body. The notion of Personality comprehends a grand total of in- terests, of which the analysis is given under the different con- stituents of our mental being — Sensations, Emotions, Volitions, and Ideas. The outgoings of this vast compound embrace the anthropomorphic views of inanimate things, and control our theories of the inanimate world. Such theories are distinct from pure Psychology, and enter into the domains of Theology and Ontology. So, also, with the part played by.Self.consciousness in Ethical speculation. Psychological criticism has a bearing in such matters, but stops short of their exhaustive discussion. G. — Clnssijicafions of the Intellectual Po/cers. — p. 343. The Intellectual powers were classified by Eeid as follows : — External Seih