lll!HII!inillllll!llllllij!l!l|{llllllljlljjlllll ; lll!!l!ll!l|llllll!llillll!lll! liil Ilil III! •• • ' ': 11 Marine Biological Laboratory Library Woods Hole, Massachusetts Gift of F. R. Lillie estate - 1977 oi ii cr m a a a m a a DEVELOPMENT AND EVOLUTION DEVELOPMENT AND EVOLUTION INCLUDING PSYCHOPHYSICAL EVOLUTION, EVOLUTION BY ORTHOPLASY, AND THE THEORY OF GENETIC MODES BY JAMES MARK BALDWIN PH.D. PRINCETON, HON. D.Sc. OXON., LL.D. GLASGOW STUART PROFESSOR IN PRINCETON UNIVERSITY THE MACMILLAN COMPANY LONDON : MACMILLAN & CO., LTD. I9O2 All rights reserved COPYRIGHT, 1902, BY THE MACMILLAN COMPANY. Set up and electrotyped July, 1902. Nortoooto J. S. Cuihing It Co. — Berwick & Smith Norwood Mass. U.S.A. C. LLOYD MORGAN, H. F. OSBORN, E. B. POULTON PREFACE THE present volume fulfils in a general way the inten- tion, expressed in the preface to the first edition : of the work Social and Ethical Interpretations, of taking up some of the biological problems most closely connected with psychological ones and falling under the general scope of the genetic method. General biology is to-day mainly theory of evolution, and its handmaid is theory of indi- vidual development. The composition of the work — like that of the com- panion volumes — has been gradual, and the positions taken have been in many cases already presented in jour- nals under various dates since 1895. This is especially true of the matter contained in Part II., regarding which a word of more detailed explanation is necessary. Since the first publication of the position, called in these pages and earlier ' Organic Selection,' by three writers independently, — Professor H. F. Osborn, Principal Lloyd Morgan, and myself, — considerable discussion has arisen about the theory, its meaning and value, and the original papers announcing the point of view have been under somewhat close inspection. The demand for reprints of these papers, in my own case — to speak only of my own case — has made it seem advisable to have them put in some available form much as they originally appeared. Despite the difficulties in the way of doing this, arising 1 Reprinted in the third edition (1902). vii viii Preface mainly from the lack of continuity and the overlapping which such papers would present when printed together under one cover, I have still determined upon this course. It was my first intention to write a general introduction to evolution, - - an exposition and criticism of the great theories, — and indeed such an intention is embodied in a contract with the publishers of the ' Science Series ' ; but it now becomes necessary to make that undertaking a separate affair, since this volume makes no pretence to completeness from such a point of view. I may add that that purpose is indeed, to my mind, excellently served by Professor H. W. Conn's able and readable book, TJie Method of Evolution, along with which students may take up also with profit the work Problems of Evolution, by F. W. Headley. This change of plan once determined upon, it seemed highly desirable that the original papers of Professors Os- born and Lloyd Morgan should be liberally drawn upon, both in the interest of cooperation — from the first most cordial and friendly - - and in that of advantage to our com- mon views ; for their positions were reached from quite different lines of approach, and the theory gains very much from this diversity of presentation. I accordingly secured their consent to my making liberal quotations from their papers ; and, as I proceeded*, it occurred to me that instead of making detached citations here and there the reader would profit more by longer quotations,- -and, indeed, that the authorities quoted would thus be much more adequately presented. Hence the full citations from these authorities in Appendix A.1 This method once The fulness of my personal recognition of them, as well as of another, is expressed, though still inadequately, in the dedication of this volume. At the same time, these writers are, of course, in no way implicated in the views of the book, except as their own statements are quoted. Preface ix approved, it became consonant with it to include the addi- tional quotations from Professor Poulton (Appendix A) and Professors Conn and Headley (Appendix B), — all of which serve as substitutes for frequent separate citations in various parts of the text, but gain in force by this ' solid ' form of presentation. I am under obliga- tions to all these writers (and also to their publishers) for their generous permission to make such free use of their writings. Principal Lloyd Morgan has also favoured me with the concise ' new statement ' - as I call it for con- venience of reference — of his views, printed, with the citations mentioned, in Appendix A. The work thus becomes, so far as this portion of it is concerned, a sort of handbook of the theory of ' Ortho- plasy,' 1 — exhibiting its original forms of presentation and reflecting its progress up to date. The defects of the method, from the point of view of the ' continuous ' reader, are so evident that I hope the critic may not find it in his heart, after these explanations, to 'rub it in.' The prin- cipal and obvious disadvantage is seen in certain necessary repetitions. Yet these are always in the course of the discussions of different phases of the larger topics; and to the psychologist, at least, repetition has its pedagogical justification. All readers are not equally mature; and even to the least immature the saying 'here a little and there a little ' is still the formula of least exertion. On the other hand, the remaining portions of the book, Parts II. and III., are mostly new matter. Of this new matter the things which are submitted by the writer with solicitude — defined as ' hope with sufficient fear ' — are the exposition of ' Psychophysical Evolution ' and the out- line sketch of the 'Theory of Genetic Modes.' These are more properly within the range of a professed psycholo- 1 The theory of evolution which makes essential use of ' organic selection.' x Preface gist's interests than are points in biology, and I am accord- ingly the less disinclined to cast them upon the water expecting some return after many days. The relation of this volume to the two earlier ones is spoken of above. The close connection of the three volumes, all of which might have been made parts of a single larger work, renders necessary the repeated citation of each one of them in the others, in a way which may seem — and has seemed, to one critic — to be a case of a writer's liking ' to quote himself/ It is really, however, a matter of division of material — with separate publication of the parts — and the references are such as one usually finds from chapter to chapter in the course of one work. The interconnection of the topics it is, therefore, with the need of expounding them, for the sake of comprehensive- ness, in this interconnection, that gives a somewhat per- sonal look to these references. J. M. B. PRINCETON UNIVERSITY, May, 1902. CONTENTS PART I THE PROBLEM OF GENESIS CHAPTER I PSYCHOPHYSICAL EVOLUTION PAGE § I. Scope and Method I § 2. The Psychological and the Biological ...... 4 § 3. Psychophysical Parallelism ........ IO § 4. Psychophysical Parallelism in Evolution 13 CHAPTER II COMPARATIVE CONCEPTIONS § i. Recapitulation . ......... 20 § 2. Natural and Functional Selection; Plasticity and Intelligence . 21 § 3. Correlation of Characters ........ 24 § 4. Psychophysical Variations 26 CHAPTER III THE DIRECTION OF EVOLUTION § i. Genetic Determination : Congenital and Acquired Characters . 34 § 2. Genetic Determination : Factors ....... 37 § 3. Intergenetic Concurrence 41 § 4. Genetic Analogies . 43 § 5. Preformism and Accommodation ....... 45 xi xii Contents PART II THE ME THOD OF E VOL UTION CHAPTER IV THE PLACE OF CONSCIOUSNESS IN EVOLUTION PAGE § i. Professor Cope's Table 50 § 2. The Origin of Adaptive Movements and Mental Characters . . 54 CHAPTER V HEREDITY AND INSTINCT (I.) § i. Romanes on Instinct ......... 61 § 2. Instinct and Lamarckism : Co-adaptation ..... 62 §3. Instinct and Lamarckism; " Selective Value " .... 64 § 4. Social Transmission and Instinct ....... 65 § 5. Instinct and Intelligence 69 CHAPTER VI HEREDITY AND INSTINCT (II.) § i. Duplicated Functions . 72 § 2. Reflexes and Imitation ......... 76 CHAPTER VII PHYSICAL HEREDITY AND SOCIAL TRANSMISSION § i. The Transmission of Intelligent Acquisitions 81 § 2. Progressive Evolution ......... 84 § 3. The Selective Process in Accommodation 85 CHAPTER VIII A FACTOR IN EVOLUTION: ORGANIC SELECTION § i. Ontogenic Agencies ......... 91 § 2. Effects of Individual Accommodation on Development ... 94 § 3. Effects of Individual Accommodation on Evolution ... 96 § 4. Tradition ........... 103 Contents xni § 5. Concurrent Determination . § 6. Functional Selection . § 7. The Relation of Organic to Natural Selection § 8. Terminology ....... CHAPTER IX MIND AND BODY § I. Resume on Consciousness and Evolution § 2. Pleasure, Pain, and the Circular Reaction § 3. Psychophysical Dualism . PAGE 106 108 "5 118 121 123 129 CHAPTER X DETERMINATE EVOLUTION BY NATURAL AND ORGANIC SELECTION § i. Criticisms of Neo-Darwinism and Neo-Lamarckism . . 135 § 2. Organic Selection as a Supplementary Principle . . . -137 § 3. The Directive Factor 143 § 4. Intelligent Direction and Social Progress ..... 144 CHAPTER XI ORGANIC SELECTION : TERMINOLOGY AND CRITICISMS § I. Terminology .......... § 2. Criticisms of Organic Selection ... . . 149 152 CHAPTER XII DETERMINATE VARIATION AND SELECTION § i. Determinate Variation § 2. Selections and Selection § 3. Isolation and Selection , . 160 . 165 1 68 CHAPTER XIII ORTHOPLASY § i. The Factors in Orthoplasy § 2. Applications of Organic Selection § 3. Intra-selection and Orthoplasy § 4. Three Types of Theory . § 5. Concurrence and Recapitulation 173 '75 183 1 86 189 xiv Contents CHAPTER XIV COINCIDENT AND CORRELATED VARIATIONS PAGE § I. Correlated Variations . . . . . . , . .196 § 2. Coincident Variation Theory not Sufficient ..... 201 § 3. Illustrations of Orthoplasy with Correlated Variation . . . 202 § 4. Natural Selection still Necessary , 209 PART III CRITICISM AND INTERPRETATION CHAPTER XV STRUGGLE FOR EXISTENCE AND RIVALRY § I. Biological Struggle for Existence ....... 213 § 2. Sorts of Rivalry .......... 218 § 3. Conscious Rivalry 219 § 4. Economic Rivalry or Competition . 221 CHAPTER XVI LAMARCKIAN HEREDITY AND TELEOLOGY § i. The Evidence in Favour of Use-inheritance ..... 226 § 2. General Effects and Specific Heredity 228 § 3. The Origin of Heredity 229 § 4. Lamarckism and Teleology . . . . . . . .231 § 5. Natural Selection not Unteleological ..,,.. 232 § 6. Cosmic Purpose and Law ........ 234 § 7. The Place of Individual Purpose in Evolution .... 235 CHAPTER XVII SELECTIVE THINKING § I. The Material of Selective Thinking 239 § 2. The Origin of Thought-variations ....... 241 § 3. Systematic Determination of Thought ...... 243 § 4. The ' Platform ' of Determination 245 § 5. The Function or Process of Mental Selection; the External World 247 Contents xv PAGE § 6. Tests of Truth in the External World ...... 250 § 7. Selection of Ideas by Attention 252 § 8. Attention Variations and the Environment of Thought. . . 256 § 9. What constitutes Fitness in the External World ? , , 258 § 10. The Fitness of Ideas; the Social Environment .... 260 § ii. Summary 264 § 12. Some Fragmentary Interpretations 266 CHAPTER XVIII THE ORIGIN OF A 'THING' AND ITS NATURE § i. What is a ' Thing ' 269 § 2. A 'Thing' is Behaviour; the 'What ' and the 'How' . . .271 § 3. The ' What ' and the ' How ' of Mind 273 § 4. The ' Prospective ' and the ' Retrospective ' 275 § 5. Probability and Design 277 § 6. Design is Genetic 279 §7. The Natural History of the Categories 281 § 8. The ' Intuition ' View 285 § 9. The Meaning of the Category of Causation 288 § 10. Definition of ' Origin '......... 291 §11. What is ' Potentiality '? 293 §12, The Origin of the Universe; Further Problems .... 298 CHAPTER XIX THE THEORY OF GENETIC MODES § i. Agenetic Science 300 § 2. The First Postulate of the Theory of Genetic Modes . . . 302 § 3. Genetic Modes 305 § 4. Genetic Science 308 § 5. The Second Postulate of the Theory of Genetic Modes . . 311 § 6. History a Genetic Science . . . . . . . .313 §7. The Biological Theory of History . . . . . . 315 § 8. The Axioms of Genetic Science ....... 322 § 9. Vital Phenomena and the Theory of Genetic Modes . . . 324 § 10. Theories of Life : Mechanical and Vitalistic .... 327 § ii. Other Applications 331 xvi Contents PAGE APPENDIX A. Original Statements of Organic Selection and Ortho- plasy: by H. F. Osborn, C. Lloyd Morgan, and E. B. Poulton . 335 APPENDIX B. Other Expositions of Organic Selection and Orthoplasy : by F. W. Headley and H. \V. Conn 353 APPENDIX C. Recent Biology ........ 372 INDEX 393 DEVELOPMENT AND EVOLUTION DEVELOPMENT AND EVOLUTION s PART I THE PROBLEM OF GENESIS CHAPTER I PSYCHOPHYSICAL EVOLUTION § I. Scope and Method THE point of view from which the questions taken up in the following pages are considered is still exclusively that of the earlier volumes of this series,1 the genetic. But the broadening out of the range of discussion to in- clude biological questions as well as psychological, makes our method now Biogenetic rather than Psychogenetic- a distinction made out in the volume on Social and Etliical Interpretations. It is not now, in these discussions, a question of the application of results, drawn from the mental life exclusively, to the larger problem of racial and social evolution ; it is rather the interpretation of the whole series of facts drawn from all these spheres, exam- ined with view to a general conception of genesis (subject to the self-imposed limitations indicated in the Preface). The emphasis is, however, still on the mental, and the 1 Mental Development in the Child and the Race, 2d edition reprinted, 1897, and Social and Ethical Interpretations,^ ed. 1902. B I 2 Psychophysical Evolution special problem is to determine what sort of a theory of biological evolution is rendered the more probable, when we recognize, together with all the established biological facts and principles, also the principles and facts of the mental life which as psychologists we are bound to accept. In the earlier volumes, we have ' read up,' so to speak, from the individual to his species and to his social group, considered as being also psychological ; now we ' read down ' from the individual, considered as an organism, to the simpler forms from which he has had his origin — all taken together as constituting an organic whole having a natural history upon the earth. Looked at in this way, the papers which follow are seen to have the unity of a common purpose, despite the gaps in the presentation of the evolution problem as a whole. They may be treated as each dealing with a narrower question, yet as having reference to the larger problem which may be called psychophysical evolution — the evolution of mind and body together. As thus falling into certain groups, the discussions may be classed under the general headings given to the main divisions or Parts of the volume: I., the problem of Genesis as such — some of its main illustrations and data; II., that of the Method of Evolution - - involving the determination of the move- ment, its direction, and the results in which the genetic factors, taken together, actually issue ; and finally III., that of Criticism or Interpretation- -of finding out the limits, tendencies, termini, and in general the competence of the genetic method in the court of science and philoso- phy. Genesis, Method, and Interpretation may be taken as the catchwords of such a series of papers whose com- mon motive is covered by the words ' Development ' and Scope and Method 3 ' Evolution/ understood in the sense of the distinction made immediately below. In furtherance of this object the most important distinc- tion, at the very outset, is doubtless that upon which cer- tain great departments of biological science are separated off from one another: that between individual Develop- ment and racial Evolution. It is Huxley to whom this distinction of terms is attributed. Development is to be used for the processes of the individual's history from the beginning of its existence in the fertilized egg to its death — the province of fact also set off by biologists by the technical term ' Ontogeny.' The province of racial de- scent, the tree of connected forms springing from a common stock, together with the entire series of forms which may be represented as branches of the tree of animal life on the earth, this province is that of Evolution, as contrasted with Development — called by the biologists technically ' Phytogeny.' The sciences of Embryology, Ex- perimental Morphology, Physiology, etc., so far as they are genetic, deal with Development ; those of Paleontology, Comparative Morphology, etc., deal with Evolution. A still more comprehensive province of research to which the genetic method directly introduces us — whether we deal with the data of mind or with those of life- -is that of the interrelation or correlation of these two great spheres, Development and Evolution, with each other. As we shall see later on, certain most vital questions of gen- etic science come up in connection with such a correlation.1 1 No single term has been generally adopted to cover the field of this cor- relation between development and evolution. The term ' ontophyletic ' (de- termination, concurrence, etc.) might be employed, or the word ' intergenetic,' for cases in which both departments of genetic process are together involved. See the remarks on page II, note. 4 Psychophysical Evolution Looked at in this way, the problem as a whole — that of Psychophysical Evolution - - requires some preliminary dissection. Certain distinctions are quite essential, the more because, if they are too often neglected by biologists and psychologists alike, it is no doubt partly because they are dealing respectively with the biological or the psycho- logical, not with both. The first of these distinctions is that between the two general provinces of research, Biology and Psychology. § 2. The Psychological and the Biological By the psychological I mean the mental of any grade, viewed from the outside ; that is, viewed as a definite set or series of phenomena in a consciousness, recognized as facts and as ' worth while ' as any other facts in nature. The phrase ' natural knowledge ' includes knowledge of psychological facts in just the same sense as that of bio- logical or chemical facts. The occurrence of a psycho- logical change in an animal is a fact in the same sense that the animal's process of digestion is. And the genetic explanations which we find it possible to offer, in this case or that, may draw upon facts of psychology, no less than upon facts of biology. In the case, for example, of one animal's recognizing another and being led by this recog- nition to carry out the act of mating, we have a complex series of events involving the psychological process of recognition, joined with that of mating in the production of one of the great results of nature, and illustrating one of the principles important to the last degree for the theory of evolution — the principle of hereditary resem- blance. The hereditary traits of the offspring are in this The Psychological and the Biological 5 case what they are because the particular parents mated ; but the particular parents mated because one of them recognized the other. The psychological fact of recog- nition is as necessary to the result as is the process of reproduction. It is a rule, indeed, that for science all facts are equal. Such a rule enables us to avoid the recondite question as to which province is to take pre- cedence in this case or that, provided we are dealing explicitly with a problem to which both sorts of fact are relevant. The recognition of psychological facts becomes especially important in view of the separate way in which analogous questions are often put in the two sciences of psychology and biology respectively. The discussion of the respec- tive spheres of these two sciences turns upon a distinc- tion of points of view. On the one hand, the psychologist as such, and for his science, must aim at the recognition only of the facts which are psychic or mental ; that is, of such as are facts to the consciousness in wJiicJi tJicy occur. These alone are psychic, and these belong to in- dividual psychology. So soon as we take up, however, the standpoint of the observer, that of the scientific man who essays to investigate some one else 's consciousness, or that of an animal, the procedure is now subject to different rules and limitations of observation. To use the terms of a recent distinction of terminology,1 the facts, while psychological, are yet to the observer not psychic. The investigation which we set ourselves when we come to discuss psychophysical evolution is ' psychological ' in this sense, that is, objective. In the earlier volumes of 1 Cf. the writer's Dictionary of Philosophy and Psychology, art. ' Psychic and Psychological.' 6 Psychophy steal Evolution this series we have taken mainly the ' psychic ' or sub- jective point of view, going over to the psychological, however, when we had occasion to reach interpretations of a biological or sociological sort. Now the main re- source is psychological and biological, the facts of mind and those of life standing on the same objective footing. We are now distinctly in the spectator's shoes, observing facts in the evolution or development of minds and or- ganisms together, at any grade in the series of forms from lower to higher. Such a distinction, it is evident, is not possible to the biologist as such : all of his facts are simply vital as con- trasted with the non-vital ; there is no question of a sub- jective over against an objective point of view. So as regards the relation of biology to psychology we have a two- fold distinction : that of the vital as distinguished from the psychological ; and, on the other hand, that of the vital as distinguished from the psychic. As to the first of these distinctions, there is a broad truth which may be stated at this point. In another place 1 it is pointed out that the entire hierar- chy of the sciences is run through by a form of interdepen- dence as between contiguous departments of research. The concept of force, when strictly construed, becomes the touchstone for the differentiation of the sciences. A force is whatever is present when one stage of a process suc- ceeds necessarily upon another stage. A force always shows itself in a change, one aspect of process succeed- ing another ; and the passing over of one set of phenomena 1 Psychological Review, January, 1902, pp. 57 f., and Social and Ethical Interpretations, 3d ed., 1902, Introduction, § 2; cf. also below Chap. XIX. §8. The Psychological and the Biological 7 into another is necessary to the notion. We are justified, therefore, in finding a force in a set of phenomena only when we are able to find a continuous process of change taking place in a continuous sort of material. Given the material of this science or that, — the arbitrarily selected domain of observation, - - we may then find forces of which this science may take cognizance when and only when the antecedent is followed by the same subsequent phenomenon, both in tliis sort of material. This, as is said above, holds so long as we restrict ourselves to a limited domain of facts. For example, in an earlier discussion, cited above, the ques- tion is that of the definition of the social. We find that various sorts of ' forces,' vital, physical, even chemical, and, by way of climax, changes due merely to the absence of certain usual conditioning limitations — all these have been called ' social forces.' But when we distinguish ' social forces ' as ' social producers of change in social material,' we are then able to subordinate all the other loosely recog- nized agencies, putting them under the heading of ' condi- tions ' — modifying, limiting, and directing conditions — under which the truly social forces operate. So it is in each science. I have suggested that the term ' nomic ' be applied to such conditions considered with reference, in each case, to the true set of forces whose play they condition. The * socionomic ' agencies, forces, etc., using again the same illustration, condition the opera- tion of the forces which are truly social. Carrying out the same distinction in this present connec- tion, we have analogous results. Psychology finds certain continuous processes of change, certain psychic states antecedent upon certain other subsequent psychic states. These, in accordance with the distinction suggested, we may 8 Psychophysical Evolution properly call ' psychic forces,' taken to include whatever we, as psychologists, find it necessary to believe is involved in the conception. The flow of the psychic, we find, how- ever, so soon as we go over to the objective or 'psycho- logical ' point of view, is conditioned upon physiological processes and functions — those of the brain and other organs. These latter condition — limit, further, direct, inhibit, in any way modify — the flow of the psychic changes. Such conditions are ' psycJionomic? This term may be used to denote the entire sphere of phenomena which are in connection with the psychological, but which, nevertheless, are not intrinsic to the series of psychic changes as such. Psychology, when considered as the science of mind, in its evolution as well as in its develop- ment, — of mind, that is, looked at from the objective point or view, — takes cognizance of the * psychonomic ' ; but when considered as a subjective science, as interpreting its own data, it does not ; but, on the contrary, it confines itself to the psychic. But now, and this is the essential point to remark in our present connection, so soon as we ask the psycho- physical question of genesis, — that of the development and evolution of mind and body taken together, - - pursu- ing the biogenetic method, this limitation no longer rises to trouble us. We include all psychophysical facts as such in the definition of our science. Changes in mind and body go on together, and together they constitute the phe- nomena. Both organic and mental states and functions may be appealed to in our endeavor to trace the psycho- physical series of events as such, since both are objective to the spectator, the scientific observer. The same relation between the intrinsic and the ' nomic ' The Psychological and the Biological 9 arises also to confront the biologist. The term ' bionomic ' 1 has already gained currency in biology ; it is the science of the relations of organisms to their environment, includ- ing other organisms. It was, indeed, by way of general- izing this important distinction of the biologist that the general point of view now under discussion was arrived at. If we bring out what is really the meaning of such a dis- tinction in biology, we are led to distinguish the bionomic forces and conditions, those of the environment in all its varied aspects, from the truly biological or vital. Bio- logical forces, properly speaking, are only those which reveal themselves in vital changes. The forces of the environment serve to condition, to limit, to direct, the operation of what is truly vital, but they cannot them- selves be called vital. They are 'bionomic.' This distinction on the side of biology is, in the writer's opinion, of considerable importance. Only by recognizing it can general biology develop as an independent science. Vital antecedents of vital changes, — always phenomena of vitality, — these are the matters of biology. Other phe- nomena may intrude upon the vital, and the morphological changes which become vital may be due in the first instance to such intrusion ; but it is only as thus directing vital processes, not as themselves having a claim to be called vital, that these things have significance for the science of life.2 While it is true of the enviroment, yet it is not necessary, as has been intimated, to treat the psychological as being bionomic with reference to life, although for the biologist, 1 Suggested, I believe, by Eimer. 3 Cf. the remarks on Natural Selection, Chap. VIII. § 7. And see the further discussion in the chapter already referred to (Chap. XIX.). io Psychophysical Evolution as such, this is an open question, yet it is a gain of no little importance that such a question may be set aside. The equality of facts becomes our rule so soon as we make the problem of evolution a psychophysical one. We may legitimately use such a combination of the mental and the purely vital as that cited above — the case of recognition- marks — without stopping to inquire in what sense a mental fact, such as recognition, can have causal value in the determination of purely physical characters in the next generation. That may be discussed in psychology, or in biology, and it must be discussed in genetic phi- losophy ; but in a department in which the psychophysical as such is the type of phenomenon expressly taken up for examination, the divorce of the two, and even the recogni- tion of a dualism between them, is unwarranted. § 3. Psychophysical Parallelism With the general understanding now arrived at, we may take a preliminary survey of the field in the light of certain current hypotheses. Among these is what is known as ' psychophysical parallelism.' This principle, as ordinarily stated, supposes a thorough- going concomitance between the two terms of the psycho- physical relation, mind and body. It states the general fact that certain changes in the organic, in those brain and nerve processes with which consciousness is associated, are always accompanied by changes in consciousness, and also, that this last is a statement which can be converted - so that it is also true that all changes in consciousness are accompanied by organic changes, in the brain and nerves.1 1 Much embarrassment is likely to arise from confusion of terms, as the problems of psychology and those of biology are brought into closest union. Psychophysical Parallelism 1 1 This principle, now made the assumption of experimental work in psychophysics, would seem to involve, and also to be supported by, certain other formulas which are a part of general scientific procedure. First, the principle of equal continuity, to the effect that there can be no breaks in either series of changes, the brain changes or the conscious changes, without a corre- sponding break in the other ; in other words, if one of the series be continuous, the other must be continuous also. This is referred to again below. Second, the principle of uniformity, to the effect that the sort of modifications which are associated one with another in brain and mind are always the same ; that is, if a certain brain process be correctly hit upon as essentially associated with a certain conscious state, then the concomitance of these two terms may be looked for The word ' parallelism ' has been in use for a long time in philosophy and psychology for the relation of body and mind, and it is impossible to discard it in the present connection. Yet the biologists have used it also for the rela- tion expressed much better by the term ' recapitulation' (so Cope), and also for the ' parallel ' or concurrent direction of development and evolution as determined by any given influences. In order to avoid such confusion, I shall use ' parallelism ' for the psychophysical relation as explained immediately above, ' concurrence ' for the determination of development and evolution in a common direction, and ' recapitulation ' for the relation of the two series whereby development reproduces evolution. The term ' concurrence ' in such a sense is suggested in my Dictionary of Philosophy and Psychology, art. ' Organic Selection.' For further illustration, we may say that psychophysical parallelism is both ' individual ' and ' racial,' and is found to illustrate both recapitulation (from the fact that the mental and organic series in develop- ment recapitulate respectively those of evolution that is, if either series does, the other, by the law of parallelism, must also), and also 'concurrence' (as a fact, i.e., based on researches which show that evolution follows a course first marked out by individual development). Recurring to an earlier sugges- tion (p. 3, above) we may note that all three of these conceptions are ' inter- genetic,' or ' ontophyletic ' (the former term being the one which I prefer, and shall use). 12 Psychophysical Evolution on all other occasions of the occurrence of either of them. This formulation is, it is easy to see, absolutely neces- sary to any science of psychophysics at all. The theory of the localization of functions in the brain, for example, assumes it. For if vision has its seat in the occipital region at one time, it may be assumed that at another time a lesion of that centre will interfere with vision, or that certain troubles of vision may be taken as evidence of lesion in that centre. If these expectations be not fulfilled, the only alternative left open to the investigator is to be- lieve that the first determination of the seat of vision was erroneous. This requirement alone — the demand for uniformity in the facts with which psychophysics has to deal — is itself sufficient to justify the acceptance of psychophysical parallelism as against all the theoretical objections that may be and have been urged. As a rule of scientific procedure, it is a necessary assumption. To deny it is to say antecedently to the actual examination of the facts which it claims to formulate, that a natural science of the individual as a whole is impossible ; for any formulation of the facts must proceed upon the assumption that they have sufficient regularity and uniformity to allow of formulation. Third, the principle must be a universal one, if it be valid at all; which means, that wherever we find a series of phenomena which are psychophysical, this principle of parallelism has its application. This leads to the necessity of extending the application of parallelism from the sphere of development to that of evolution, as those terms are distinguished on an earlier page. This may now Psychophysical Parallelism in Evolution 13 be explained in a little more detail, after which certain applications of the two preceding principles — continuity and uniformity — may also be indicated. § 4. Psychophysical Parallelism in Evolution I have said that the principle of parallelism is universal, that is, that it is applicable to all instances in which the facts on either side are of the order indicated by the term ' psychophysical.' The great spheres in which such a truth would have bearings are the two covered by individual life history, from life to death - - ontogeny, the sphere of development — and the race history of a species, or of all life upon the earth considered as showing a series of forms connected by links of progressive descent- -phylogeny, or evolution. These two forms of parallelism we may call respectively ' individual' and 'racial.' Earlier discussions of parallelism have had reference largely to the former sphere, and the question has come up for the most part in connection with theoretical discussions of the relation of mind and body. Furthermore, the concomitance of development of mind and body in the individual has had recognition, and its illustrative value for the topic of evolu- tion has been written about — though not at all adequately. The corresponding racial application of parallelism in the sphere of evolution has not, to the present writer's knowledge, been explicitly made ; that is, as going neces- sarily with an individual parallellism, as part of an in- tergenetic conception. And yet the two cases must necessarily go together, and no final formulation is possible of the relation of conscious changes to bodily changes which does not have direct application in both these spheres, and indeed the same application in both 14 Psychophysical Evolution of them. For in psychology, as in biology, the race series is but a continuous line of individual generations, and to ask the question of the race is but to ask whether parallelism holds for any given number of generations of individuals wherever chosen in the line of descent — this provided we admit that descent is by some form of continuous hereditary transmission. The questions which arise about heredity, however, do not trouble us, seeing that they are not within the domain of strictly psychophysical inquiry, except in so. far as our theory must explain the inheritance of both physical and mental characters to the same degree. For example, the question of the ' continuity of germ plasm ' may be de- cided one way or the other — either for or against the actual continuous transmission of an identical substance — without raising the question of a corresponding transmis- sion of anything psychological. For if there be breaks in the psychological series at those nodal points at which gener- ation succeeds generation, there are also, by the principle of equal continuity, discussed above, breaks also in the psycho- physical, and we may find the psychological series beginning again at the appropriate point in the development of the organism of the new generation — the point at which the psychophysical again begins. In other words, the advantage gained from the psychophysical point of view is that if there be apparent gaps in one of the series, we may either as- sume them filled up by theoretical parallelism with the other series at these points, at which it has no gaps, or we may -if we deny continuity to either — make gaps in the second series in correspondence with the gaps found in the first. We have in any given case, in short, either a psychophysical fact, or we have not : if we have, then Psychophysical Parallelism in Evolution 15 either series is sufficient to carry us over the critical point ; if we have not, then the break in one series is sufficient evidence of a corresponding break in the other also. The principle of parallelism assumed, we claim once for all the right to neglect the relation of the tivo terms, mental and pJiysical, in all circumstances whatsoever.1 On this way of conceiving the scientific inquiry, we may proceed unhampered by the problems which trouble the philosopher. We do not have, for example, to adopt Professor Lloyd Morgan's theory of 'metakinesis,' postu- lating something quasi-mental to fill out the breaks in the psychological series, at points at which we have no sign of the presence of consciousness. Nor do we have to embrace the idealistic theory of knowledge of his critic, Professor Karl Pearson, to do away with a troublesome brain substance, which at times becomes uncomfortably prominent. The formulations of ' shorthand,' to use Pear- son's phrase, may be made for both series together. This is required for such a problem as that of evolution. We do not have one series of genetic forms, the mental, evolving under shorthand formulas of its own ; and another series, the organic, doing the same thing under different formulas. On the contrary, the two sets of facts really go together in the one set of formulas. This is what I am arguing for. We often find it necessary to use the mental facts as antecedents of the physical facts, often the physical as antecedent of the mental, and again, often the psychophysical as antecedent of either or both. This possibility is presented with more detail on a later page (Chap. IX. § 3). The twofold application of parallelism, considered as an 1 Cf. the further remarks on the construction of heredity below, Chap. XVI. M 1 6 Psychopkysical Evolution assumption of psychophysical research, may be repre- sented by the accompanying diagram. The two vertical lines (M, B) represent the two series in the evolution of the race-forms of organisms — the dotted line (M, mind) being the mental, and the solid line (B, body) the physical. Across these at any point we may draw similar horizontal lines (m, b) representing individual development in any given genera- B tion ; these are also, of course, dotted (m) and solid (b\ The full theory ZL ^ of parallelism requires, not only that ~b~ we make the two horizontal lines parallel, — the ordinary application in ontogeny (O); but that having gone so far, we must also draw the two parallel vertical lines — the ap- plication in phylogeny (P). At whatever point in the line of descent we apply the principle to individual develop- ment, we must perforce raise the corresponding genetic questions about the evolution which has led up to the birth of such individuals at that point. And the series of ' shorthand ' formulas, laws — in the prosaic equivalent of everyday science, ' results ' — at which we arrive, must involve the three great problems represented by the four lines : parallel development (the relation of m to b), parallel evolution (the relation of M to B), and intergenetic correlation (the relation of mb to MB). Furthermore, when we recognize in places the absence of the facts we should expect, — apparent breaks in either one of the lines, — we may resort to the resource of using the correspond- ing facts from the parallel line at the same level, and even those from the analogous line of the other pair of parallels, Psychophysical Parallelism in Evolution 17 so far as there are known facts in the particular case which lend themselves to such procedure. The philosophical problem is illustrated by a similar dia- gram in the section below already referred to (Chap. IX. § 3). In that connection it is a question of reaching an inter- pretation in a statement in which the independence of the two series is in so far denied — the representation being that of a possible single line which can be substituted for the two in their development. A similar philosophical problem is open also in the matter of evolution. Such an interpreta- tion in either province, it is maintained in the later place, is not possible to the scientific inquirer as such, although it may be possible to arrive at a philosophical explanation of the dualism of mind and body. In our present connection the urgent need is in another direction — to hold a level balance and give each side its due. It is an equally embarassing thing for the scientific inquirer in one case to be a monist to such a degree as to deny one of these lines altogether — the mental in favour of the physical ' short- hand, ' or the physical in favour of the mental — and in another case to insist upon the separateness of what nature shows us always joined together, to the extent of refusing to use facts from one of the series to illumine and even to explain facts in the other. This last-mentioned attitude is especially to be con- demned in the discussion of genetic questions - -those of development and evolution. Here the question turns upon the genetic antecedents of a given fact, be it function, act of behaviour, mental state, instinct, or other, in this organism or that. No tracing of genesis is possible, of course, except by actual observation of the facts under which the phenomenon in question arises. Now to refuse c 1 8 Psychophysical Evolution to see certain of the antecedents because they are not physical, or because their physical counterpart is not known, or the reverse, that is, to observe only the mental antecedents of the fact in question, is suicidal to genetic science. It not only omits facts from its formulations, but it actually does violence to facts. For with the omission goes the commission of the positive error of arriving at an interpretation which is false.1 A remarkable instance illustrating the necessity of recognizing both orders of facts is to be found in the theory — and the history of the theory — of 'warning colours.' As preliminary to the theory there is the fact of coloration, which is distinctly physical. The question is as to its origin. The theory holds it to be due to the warning given to other individuals that a particular colouring is dis- tasteful or poisonous. Now, in order that this warning be given, the biologists tell us there is necessary a cer- tain education of the hostile individuals. The creatures have to learn the meaning of the coloration ; and this learning involves profiting by experience. If each creature made the same experiment each time instead of profiting by his own experience, or if each had to learn for himself, instead of profiting by the experience of others through imitation, etc., of course there would be no utility in the colouring as giving warning. Here is as distinctly a mental process involved as any one might cite. To refuse to recognize it would be to throw away what is generally recognized as the true theory of these cases of coloration. 1 Cf. the criticism of Professor James' theory of the separateness of the psychological and physiological ' cycles ' in my Social and Ethical Interpre- tations, Sect. 42. See also the further discussion in Chap. XIX. on ' Genetic Modes,' below. Psychophysical Parallelism in Evolution 19 The action of natural selection, I may add for complete- ness, secures the survival of the insects so coloured, seeing that being warned, their enemies let them alone. The possibility of the evolution of the definite coloration turns, in fact, upon this series of psychological processes.1 1 On this particular topic see Professor Poulton's Colours of Animals. A recent concise statement of the facts by the same writer is to be found in the Diet, of Phi los. and Psyc/iol., arts. ' Warning Colours,' and ' Mimicry.' CHAPTER II COMPARATIVE CONCEPTIONS § I. Recapitulation THIS way of looking at the two spheres of development and evolution, as involving an application of the one prin- ciple of parallelism, carries with it certain consequences of considerable interest. In the first place, it requires us to carry over into the genetic treatment of psychology the same thorough-going genetic point of view which evolu- tion postulates in biology. And with this goes the question of the application to the facts of the one of the principles already established for the other. The great law of recapit- ulation at once comes to mind, the law with which we have been having considerable to do in the earlier volumes of this series. If we hold that mind and brain processes are parallel as well in the species as in the individual, and also hold that the brain series in the individual's development recapitulates in the main the series gone through by his species in race descent or evolution ; then it follows that the law of recapitulation must hold also for the mental. This has been recognized and the limitations of it have been pointed out in Chap. I. of Mental Develop- ment : * and a further general application of the idea to 1 In that place, under the topic ' Analogies of Development,' the main ' epochs ' of growth in each series, which illustrate the recapitulation of evolu- tion by development, are briefly indicated. The following quotation from that work presents a preliminary statement of the general thought which is now worked out explicitly and with greater detail in these pages : " Assuming then that there is a phylogenetic problem, — that is, assuming that mind has 20 Plasticity and Intelligence 21 the social life is worked out in the Social and EtJiical Interpretations. The further extensions which the theory of biological recapitulation has recently undergone, prom- inent among which is the theory that regression shows itself first in individuals and afterward in the same direc- tions in the species, should also find confirmation if they be true, or the reverse if they be not true, from the facts of genetic psychology.1 § 2. Natural and Functional Selection : Plasticity and Intelligence Apart from the question of recapitulation, which I have given this prominence both from its general character and also from the fact that it has survived very consider- able criticism in recent literature, we find certain points had a natural history in the animal series, — we are at liberty to use what we know of the correspondence between nervous process and conscious process, in man and the higher animals, to arrive at hypotheses for its solution; to expect general analogies to hold between nervous development and mental development, one of which is the deduction of race history epochs from individual history epochs through the repetition of phylogenesis in ontogene- sis, called in biology ' Recapitulation ' ; to view the plan of development of the two series of facts taken together as a common one in race history, as we are convinced it is in individual history by an overwhelming weight of evi- dence; to accept the criteria established by biological research, on one side of this correspondence, — the organic, — while we expect biology to accept the criteria established, on the other side, by psychology; and, finally, to admit with equal freedom the possibility of an absolute beginning of either series at points, if such be found, at which the best-conceived criteria on either side fail of application. For example, if biology has the right to make it a legitimate problem whether the organic exhibits a kind of function over and above that supplied by the chemical affinities which are the necessary presuppositions of life, then the psychologist has the equal right, after the same candid rehearsal of the facts in support of his criteria, to submit for examination the claim, let us say, that ' judgments of worth ' represent a kind of deliverance which vital functions as such do not give rise to." (First ed., pp. 14 ff.) 1 See also Chap. XIII. § 5, on ' Concurrence and Recapitulation.' 22 Comparative Conceptions at which what may be called ' comparative ' questions arise. By this I mean points at which the interpreta- tion of a series of facts has been fairly made out, or the facts at least formulated, on one side of the two parallel series, and we may properly ask how far the same or an analogous interpretation or formulation is possible on the other side. For example, the law of natural selection from spontaneous variations, which makes use of the criterion of fitness or utility only — what can we say of mental evolution from this point of view ? We have here to apply a biological conception directly to the mental. Again, in development the mind seems to pro- gress by a certain function of selection by which it brings itself into better accommodation to a complex mental and physical environment. Here is a certain formulation on the mental side, a function so well recognized that the criterion of consciousness in an organism is often said to be the exhibition of a ' selective ' reaction. What now can the biologist do with this in his theory of organic development ? Both of these instances are enlightening for the deri- vation of what I am calling * comparative conceptions.' The union of the two seems to require that the brain variations by which evolution proceeds be of such a sort that their very utility — that for which they are se- lected — is in the line which mental development by a selective function in each generation acquires. Now, in fact, we find this requirement fulfilled in the evolution, by variation and natural selection, of increasing plasticity of nervous structure. By this, not only does it appear that mental evolution progresses by variation, keeping pace with organic (a correlation in evolution), but also Plasticity and Intelligence 23 that organic variation is in a direction which furthers accommodation, or ' educability,' by mental selection in individuals (a correlation in development). In the latter respect, the utility of plasticity, as permitting mental de- velopment and selective accommodation, is so great that it outweighs in evolution all other biological characters, and as embodied in the brain, becomes the great outstand- ing fact throughout the ascending series of mammalian forms. Once given the presence of consciousness, with its methods of psychological accommodation, and it carries with it organic adjustment ; while the operation of variation with selective survival tends to perfect it. Moreover, in psychophysical accommodation we have the problem of selection set in a new form inside of the func- tions of the organism itself. Consciousness, mind in any form, is a character ; its functions are always psycho- physical in their operation. How then can consciousness select without violating parallelism ? In answer to this it may be pointed out that accommodation is another comparative conception ; for it is only by an application of the operation of natural selection in the form of survival from overproduced functions, such as move- ments, dispositions, etc., that consciousness can effect selective adjustments ; that is, there is no other way short of a miracle. This in general outline is the conception of functional selection.1 So a completed view of psycho- physical accommodation requires (first) natural selection, operating upon (second) variations in the direction of plasticity, which allows (third) selective adjustment through 1 Worked out in Mental Development on the basis of the theory of ' sur- plus discharges ' of Spencer and Bain. See also the recent work on Animal Behaviour, pp. 163 f., by Professor Lloyd Morgan. 24 Comparative Conceptions the further operation of natural selection upon the organ- ism's functions. So we have certain comparative conceptions : variation with natural selection, consciousness or intelligence with plasticity, and accommodation by functional selection. They are comparative in the sense which is now occupy- ing us, that is, psychophysically ; since the meaning of any one of them is not exhausted in its application to either mind or body, without appeal also to the other of these two psychophysical terms. For example, the meaning of the evolution of the brain cortex, with the extreme plasticity which is its main char- acter, through the entire line of mammalian descent, can be understood only when we recognize the evolution of intelligent endowment which accompanies it ; and the method of the selective function of consciousness can only be understood, in my opinion, in the light of the method of survival by selection from overproduced variations, which is the method of natural selection. § 3. Correlation of Characters Another highly interesting comparative conception is that connoted by the biological term 'correlation.'1 This idea covers the fact that certain characters of the organ- ism are correlated with, connected with, or in other regu- lar ways related to, certain other characters, in such a way that modifications or variations of the one are accom- panied by changes in the other also. This is true, not only of those characters in which it is difficult to deter- mine the precise function, and of which, therefore, the definition itself is difficult and uncertain, since it involves 1 See instances given in Chap. XIV. §§ 1-3. Correlation of Characters 25 others as well ; but also for those which are remote from one another, as, for example, the internal glands whose secretions are found to be in some obscure way correlated with general conditions of the organism. This principle, when once formulated, will undoubtedly be important ; but as yet no exact laws of correlation have been made out. Yet it is quite allowable to say, in the same general sense, that psychological and psychophysical correlations hold. The psychophysical relation is itself a correlation having many special illustrations, such as the correlation between plasticity and intelligence, that between the fixity of ner- vous processes and the corresponding impulses, instincts, etc. Indeed, the psychophysical question, when put in a particular case, is really one of determining the correlation of the characters which consciousness shows with those of the organism as such. And it follows that, wherever a mental character enters into the complete carrying out of a physical function, it must have its place assigned to it, according to what has already been said, in the complete determination of the genetic significance of that function. Furthermore, we may say that no physical character which has mental correlations is completely understood until these latter are exhaustively determined, and also that no mental character escapes physical correlation. Recent research in the psychological and physiological laboratories is establishing many such psychophysical cor- relations : that of emotion with motor processes, of atten- tion, rhythm, and the time-sense with vasomotor changes, that of mental work with nervous fatigue, and so forth through all the main problems of this department. All this affords, in so far, at once illustration and proof of the general formula of psychophysical parallelism. 26 Comparative Conceptions § 4. Psychophysical Variations Allusion has been made to the great biological topic of variation as embodying a conception common to the two series - - mind and body. It is only recently that the theory of selection from congenital variations has been brought over into psychology. Formerly the idea of hereditary transmission of the results of mental education was simply assumed. But the failure of that idea in biol- ogy has led to the revision of the facts with an equally pronounced verdict against it in psychology also. Begin- ning with certain brilliant independent examinations of the question, notably that of W. James,1 the theory of mental variations has come in to account for the evolution of mind in strict correlation with that of the organism. We find not only the correlation of intelligence with plasticity, as pointed out above, but also many other correlated details which the psychophysical processes actually exhibit. This means that natural selection has worked upon correlated psychophysical variations — not upon organic variations merely. In other words, it has been the psychophysical, not the physical alone, nor tJie mental alone, which lias been tJie unit of selection in the main trend of evolution, and Nature has done what we are now urging the science of evolution to do — she has carried forward the two series together, thus producing a single genetic movement. It would have been impossible for mind to develop by selec- tion with reference to utilities for which the necessary organic variations were not present ; and so also it would have been impossible for the organism to evolve in ways which the consciousness of the same animal forms did not 1 Principles of Psychology, II. Chap. XXVIII. Psychophysical Variations 27 support and further. There could not be independence ; there must be correlation. This is illustrated by several of the facts and principles pointed out in the following pages. It has been argued in the earlier volume on Social and Ethical Interpretations (Chap. VI.) that emotion shows a development from an ' organic ' to a ' reflective ' or intelligent type, which latter, however, utilizes in its expression the same organic pro- cesses as the former ; and it is there stated that this could have come about only by the sort of correlation now under discussion. Only those reactions of the organism, selected for their utility in offence, defence, etc., would survive, which could either be actually used for the higher purposes of mind, or which, at least, did not stand in the way of the exercise of the higher functions. Both of these possibili- ties are realized, and in some cases we find the presence of vestigial 'expressions,' now harmless although no longer useful ; while in other cases the original reaction has been modified to serve the new purpose. In certain cases, also, these vestigial reactions or dispositions are, in some degree, disturbing factors to the possessor of the new func- tions.1 It is argued below (Chap. VI. § i) that both the in- stinctive or reflex and also the intelligent performance of a given function may coexist side by side, each having utility and each preserved for its utility - - an additional resource thus being given the possessor in coping with complex circumstances. In this case, there has been a selection of variations toward the plasticity which the evolution of in- telligence demanded, together with the growth of the appa- ratus of voluntary movement, while at the same time the fixed connections requisite to the reflex or instinctive per- 1 So blushing, as is maintained in the work mentioned, Sects. 134 f. 28 Comparative Conceptions f ormance of the same functions have not been disturbed, the same apparatus being so modified, however, as to serve the two utilities in question more or less independently. Another case of interest from the psychological point of view is that of the genetic interpretation of the function of imitation, itself quasi-instinctive, or impulsive, in relation to other mental and organic functions. As I have argued in detail in Mental Development, considered genetically as a type of reaction, imitation involves reference to an end or 'copy,' which is the prime characteristic, also, of intelligent action; but it is held down to a definite psychophysical process, called the 'circular' process, whereby the copy is reinstated by the act of imitation. For example, my parrot has just learned to say ' Hulloa ' imitatively. He learns to pronounce this word just as an intelligent child would learn to do it ; but he cannot vary, modify, or inhibit it, nor exercise selection in the manner of his doing it. His act seems to lie, therefore, as type of function, midway between the congenital instinct and intel- ligent selective action. The present writer considered this function to be probably a case in which natural selection has put a premium upon the acquisition of adjustments which would keep a creature alive and give the species time to acquire the congenital mechanism for performing the same functions — illustrating what is called, below, 'organic selection.' Imitation would, thus considered, in many cases aid the development of instincts ; in all cases, that is, in which the instinctive performance would, by reason of promptness, accuracy, etc., be of greater or of additional utility. But about the same time Professor Groos published his theory of play in a work in which imitation is held to have just the opposite genetic relation PsycJiophysical Variations 29 to instinct and intelligence.1 According to Groos, the imitative performance, by reason of its character as pre- senting a certain degree of selective learning and accom- modation, tends to supplant the fixed reactions of instinct, and so to put a premium on variations toward the plasticity required by increasing intelligence. It now transpires that Professor Groos and I are able to accept each the other's position, and so reach the common view that it depends upon the exigencies of the particular adaptation required by the animal species as to what a particular imitative reaction means. If an imperfect instinct is in the way of develop- ment for a marked utility, imitation, by supplementing it, would undoubtedly aid its survival and evolution in the way indicated above. Yet, on the other hand, if an instinct is in process of decay, — or if the conditions make its decay desirable, — Professor Groos' principle would then come into operation. The imitative performance would repre- sent a form of variation which would be in the direction of the plasticity of intelligence, and creatures would be selected who performed the function imitatively, until fur- ther variations toward plasticity were forthcoming. In either case, and especially in both cases working in nature together, we have a clear illustration of the sort of psycho- physical ' togetherness,' so to speak, the indissoluble cor- relation, into which the organic and the mental are welded in the process of evolution. The fact of correlated variation, moreover, is to be car- ried over to the relation between organic and mental varia- tions in different individuals. Many instances are known which prove it ; that they are not more numerous is due, 1 The Play of Animals, Eng. trans. Cf. the notice of that work below, Appendix C. 30 Comparative Conceptions I think, to the neglect of the recognition of it in seeking genetic explanations. For example, sexual selection re- quires correlation between the organic characters of col- oration, etc., in the male, and the mental apprehension and the sexual impulse of the female. So the evolution of infancy requires correlation between the physical helpless- ness of the young, and the maternal instinct and affection of the mother. In the evolution of gregarious life we find a vast system of correlations of physical characters, — expressions, attitudes, behaviour in general — which are interpreted and responded to psychologically by other members of the group ; these physical and psychological characters together make up the psychophysical equip- ment of the individuals for their common life. In a later place (Appendix C) the possibility of correlation between mental characters and sexual variations is pointed out in connection with Pearson's theory of ' reproductive selec- tion.' It is remarked also in the same place, that one great form of isolation, that due to social barriers which create segregation and preferential mating, and so effect physical evolution, is not noticed by Romanes in his description of the different forms of isolation ; here there is involved a correlation between the mental functions embodied in per- sonal choice, social convention, law, etc., and colour of skin or other physical characters which either attract or repel. The theory of 'secondary sexual characters' in man and woman extends to mental traits, and points out correlations not only between many characters in the same individual, but also between these of individuals of the opposite sex. The theoretical importance of this sort of correlation appears more fully when we look closely at what it involves. In the first place, negatively : if it be true that the unit of Psychopkysical Variations 31 selection in evolution is often a psychophysical function or character, it may be only the failure of psychophysical observation which prevents the genetic explanation of a series of organic changes. The search for utilities should be extended to the mental sphere. The larger utility of the psychological or the psychophysical may be the key- note in a case of survival ; and the failure to discern this utility may block our scientific progress. So it is, for example, in appreciating many forms of play. If we adopt the * practice ' theory, which holds that play is a means of preparation, through preliminary practice, for the strenuous specific activities of adult life, we must recognize that it is often mental practice — in accommoda- tion, judgment, social adaptability, etc., — or the training of mental functions, which is the critical utility ; and that to understand this utility is at once to secure an applica- tion of natural selection, where otherwise, from the purely organic point of view, no adequate ground of selection would have been discoverable. While so much is true negatively, the matter has also a positive aspect. The actual construction of a view regard- ing a particular function or character can often be arrived at only by weighing the psychological facts. So in the case of the function just cited, animal play. There were earlier theories of play. The ' surplus energy ' theory of Spencer was generally held, despite the quite valid criticism that it had the negative defect pointed out immediately above : no adequate selective utility attaching to play was involved so long as it was thought to be due to discharges of surplus animal vigour only. The consequence was that play — together with the whole province of art, which is thought by many to have its roots in the play- 32 Comparative Conceptions impulse — was looked upon as a by-product, an unjustified remainder, not due to selection at all, and subserving no utility in the economy of the genetic processes of evolution. Now, thanks to the illuminating works of Groos,1 develop- ing the scattered hints of others, we discover the psycho- logical and sociological utilities of play, which supplement its biological utility in the practice theory ; and the whole is an important contribution, not only to the body of evidence for Darwinism, but also to the psychophysical interpreta- tion of evolution. Play and art are now no longer luxuries for the rich ; they are necessities as well for the poor — to speak in terms not entirely figurative. Indeed, in this conception of correlated variation many of the mysteries of evolution are pooled. The position taken above, and elaborated in the later chapter, to the effect that the conditions which are ' nomic ' to a genetic move- ment are to be carefully distinguished from the forces intrinsic to the movement, avails to indicate the capital importance of the fact of variation in mind and body together. Natural selection is in itself a negative prin- ciple, a ' nomic ' or directive condition ; heredity is a principle of conservation in so far as it is specifically and only heredity ; and the remaining foundation stone of the entire evolution structure, variation, remains the point of direct and emphatic importance. In it the intrinsic vital processes must exhibit themselves. It is by variation that the materials of selection arise, it is the character of varia- tion that must decide the question of determination — the issue between vitalism and the opposed views. Here, in the opinion of the writer, much of the great biological work of the future is to be done. Witness, indeed, the 1 The Play of Animals, and The Play of Man. Psychophysical Variations 33 researches already carried out by statistical methods, aim- ing to determine the actual facts as to whether variations have an intrinsic drift in certain directions, or whether the appearance of such a drift is entirely due to processes of selection within or without the organism. The newer view, which holds that species originate in abrupt or ' sport ' variation, called ' mutation,' strikes at the very founda- tions of the Darwinian conception — that is, if mutation be considered not merely an exceptional case but the normal mode of the origin of species.1 We may accord- ingly go a little more fully into the requirements of a theory of determination. 1 The appearance of the new journal, Biometrica, is witness to the vitality of the movement to treat biological phenomena, notably variations, by exact statistical and mathematical methods. Cf. the summary articles by Davenport and Weldon on ' Variation,' and those on 'Natural Selection' and ' Muta- tion ' by Poulton, in the Diet, of Philos. and Psychol. On mutation see De Vries, Die Mutations tkeorie (1901). A summary article by De Vries is to be seen in Science, May 9, 1902. It seems to the present writer a very long step from the observation of single cases, admittedly very rare, of the persistance of abrupt variations, to the theory of the ' Origin of Species by Mutation.' For an able negative criticism of De Vries' work, written from the point of view of recent statistical ' biometric ' researches, see Weldon, in Biometrica, Vol. I. Part 3, pp. 365 ff. CHAPTER III THE DIRECTION OF EVOLUTION § I. Genetic Determination: Congenital and Acquired Characters THE problem of determination, in its varied aspects, is no more than the problem of the method of evolution; hence the attention given in the following pages to this topic in both its phases, that of evolution and also that of development.1 As an intergenetic conception it takes form as follows: first, what determines the development of the individual, both bodily and mentally, or in a word, psychophysically ? — second, what determines the evolution of the species, in both the same two phases, that is, psychophysically ? — and third, how can these two forms of determination work together so that race determination is ' concurrent ' with individual determination ? It is only when all three phases of the problem are held together that the extraordinary complexity of the data comes fairly out. The data of fact and of principle resting upon formulations of fact, as they appear in the present state of knowledge, may be pre- sented somewhat as follows, while the later chapters may be looked to for treatment of various of the subordinate topics which fall under the larger heading. First, individual development seems to take place by gradual accommodation to environment on the basis of 1 See especially Chaps. X. and XVII. below, on 'Determinate Evolu- tion ' and ' Selective Thinking.' 34 Congenital and Acquired Characters 35 the congenital hereditary impulses which characterize the species. This is true both of mind and body ; and the relation of the respective functions of mind and body varies with the place of the creature in question in the scale of life — with what we may call, technically, its 'grade.' The correlation already pointed out between increasing plasticity of the nervous system and increasing mental endowment holds as we ascend from a lower to a higher stage. We accordingly have an increasing dependence upon accommodation of the mental type as we ascend higher in the scale. The range of possible accommodation of tlic organism of a whole becomes, therefore, wider and its congenital impulses less fixed as evolution advances ; there is constantly less dependence upon definite heredity, and more upon the inheritance of a general mechanism of accommodation of a psychophysical sort, as we ascend the animal series.1 Recognizing progress in progressive accommodation, with plasticity of mind and body, as the direction in which evolution is determined, we may set that down as the first point in our argument. The method of accommodation, its progress by the selection of adaptive movements and thoughts from overproduced cases by trial and error, may be left over for the present. Second, it follows that the distinction so long dominant in biology between ' congenital ' and ' acquired ' characters, cannot be sharply drawn. All characters are partly con- genital and partly acquired. The hereditary impulse is at the start in each case a rudiment (Aulage), which is to de- velop into what the environment, within which its native tendencies must show themselves, may permit it to become. 1 Professor Ray Lankester has paralleled this with the advance in size and complexity of the mammalian fossil brain {Nat we, LXI. p. 624). 36 The Direction of Evolution This impulse is definite enough in many cases, where the conditions do not require accommodation and modification ; but where these demands are urgent upon it, it is surprising what transformations it may undergo. Recent results of embryological and morphological research have proved this so clearly that a school of biologists, called by Delage * Organicists,' 1 has arisen, who place the emphasis in all evolutionary change upon the necessity of the organism, and of its particular organs, to become what they are stimulated to become under the stress of the environment, or, failing to meet these requirements, to die in the attempt. This suggests an important modification of the strictly ' Preformist ' view, made extreme in the earlier writings of Weismann, according to which the accommodations of the individual organism are of no importance, being simply the unfolding of what is preformed in the germ. For even if we admit, as we may, the non-inheritance of acquired characters, we may still hold the general view of the organicists, and also maintain that the hereditary impulse becomes more and more unformed^ rather than preformed, as we advance in the animal scale; each succeeding genera- tion through its own development, in its own life history, making more of the essential accommodations which give it its generic and specific characters. This Weismann has lately in part recognized, in his theory of ' intra-selection ' built up upon the views of Roux. Third, if these be the safe results of research in the sphere of development, we then have certain additional 1 ' The Organicists oppose [to other theories] the combination of a mod- erate predetermination with the continually acting and necessary forces of the environment, which are not simple conditions alone, but essential elements in the final determination.' (Delage, La Structtire du Protoplasma, p. 720. Delage's personal views are cited in Chap. XIII. § 3, below.) Genetic Determination: the Factors 37 guiding indications for the problem of determination in the sphere of evolution. The evolution series becomes in its hereditary character more and more indeterminate, more and more indefinite, in respect to what will be produced by the union of the heredity impulse with the conditions of development of the successive generations of individ- uals. There is a general direction of progress, secured by the natural selection of variations in the direction of the plasticity which increasing accommodation requires ; but the utility of this shows itself in the decay of special congenital functions and the increased freedom of the organism in working out a career for itself. Thus there is secured a blanket utility, as it were, a general character, through the operation of natural selection, which pro- gressively supersedes and annuls many special utilities with their corresponding adaptations, while, at the same time, other special functions having special utilities are given time to reach maturity by variation and selection. § 2. Genetic Determination : the Factors The truth of this position regarding the direction of evolution appears from the detailed explanations by which the two leading positions of this work are supported in the following pages. Of these two positions the first is that of Organic Selection, explained and applied with considerable rep- etition below. This position is the general one that it is the individual accommodations which set the direc- tion of evolution, that is, which determine it ; for if we grant that all mature characters are the result of hereditary impulse plus accommodation, then only those 38 The Direction of Evolution forms can live in which congenital variation is in some way either ' coincident ' with, or correlated with : the indi- vidual accommodations which serve to bring the creatures to maturity. Variations which aid the creatures in their struggle for existence will, where definite congenital en- dowment is of utility, be taken up by the accommoda- tion processes, and thus accumulated to the perfection of certain characters and functions. The evolution of plasticity, on the other hand, could only itself have taken place by the cooperation of accommodation using the variations toward plasticity already present at each stage, and thus saving and developing such variations. This gave an ever higher platform of variation from which steady refinement of plasticity and its accompanying intelligence was all along possible. Organic selection becomes, accord- ingly, a universal principle, provided, and in so far as, accommodation is universal. Accommodation, therefore, when all is said, is a posi- tive thing, a vital and mental functional process supple- mentary to the hereditary impulse. It must be considered a positive factor in evolution, a real force emphasizing that which renders an organism fit ; whereas natural selec- tion, while a necessary condition, is yet a negative factor, a statement that the most fit are those which survive. If it be true that those variations which can accommodate, either very much or very little, to critical conditions of life are the ones to survive, and that such variations will be accumulated and will in turn progressively support 1 See below, Chap. XIV., for treatment of the distinction indicated by these phrases. ' Coincident variation ' was suggested by Professor Lloyd Mor- gan : cf. below, Chap. XI. § I, and Lloyd Morgan's Animal Behaviour ; P- 37- Genetic Determination : the Factors 39 better accommodations, then it is the accommodations which set the pace, lay out the direction, and prophesy the actual course of evolution. This meets the view of the Lamarckians that evolution does somehow reflect indi- vidual progress ; but it meets it without adopting the principle of Lamarckian inheritance. The second general position advocated, on the basis of facts, in the following pages is that of Social Heredity,1 or Social Transmission, with Tradition. This too falls into place in our general theory of determination. If accom- modation is a fact of real and vital importance, then some natural way of regulating, abbreviating, and facilitating it would be of the utmost utility. If animals were left to constant experimentation each for himself, they would die, as we have said above, before they made much devel- opment. We find that an important function of conscious- ness is that it enables them to profit by experience. By memory, association of ideas, pleasure and pain motiva- tion, they abbreviate, select, and handle experience to the most profit. But there also arises an additional resource — and certainly a very important one — by which they are en- abled to pi'ofit as zucll by tJie experience of others. So soon as animals can use their native impulses in an imi- tative way, they begin to learn directly, by what may be called 'cross-cuts' to a desirable goal, the traditional habits of their species. The chick which imitates the hen in drinking does not have to wait for a happy accident, 1 In the earlier volumes of this series, where the psychological process of acquisition is much in discussion, the phrase 'Social Heredity ' is largely used. In the following pages, wherever possible, the expression ' Social Transmis- sion' is employed. 4O The Direction of Evolution nor to make a series of experiments, to find out that water is to be drunk. The bird deprived of the presence of others of its kind does not learn to perfection its proper song. All the remarkable accommodations of an imitative sort, so conspicuous in the higher animals, enable them to acquire the habits and behaviour of their kind without run- ning the risks of trial and error. Calling this store of habits of whatever kind ' tradition,' and calling the individ- ual's absorption of them and his consequent education in tradition his ' social heredity,' we have a more or less independent determining factor in evolution. For these accommodations are the cream of the needs of life, they represent the essentials of education, the sine qua non in an animal's equipment ; so the accommodations which must be reproduced in race evolution, as adaptations which the species must effect, are in these lines. The influence of organic selection is, therefore, exerted to determine, by the selection and accumulation of varia- tions, the congenital equipment which most readily util- izes and supplements these traditional modes of behaviour. The two factors work together and for the same general result. There is, therefore, in tradition a further determining factor. Natural selection plays about it to fix a requisite function here, to eradicate what is unnecessary and non- useful there — in short, by its omnipresent operation on this character and on that, to perfect the individual for the most adapted life. It is here also that we touch upon the border line be- tween psychophysical evolution and social evolution, a line which we may not now cross. Suffice it to say that once the community of tradition is established and the fitness Intergcnetic Concurrence 41 of the individuals secured for a life in some degree of gre- garious habit, and we then find the great bend in the line. Progress from now on ushers in the dominance of mind in the modes of conscious social life and institutions. the modes of conscious organization which characterize § 3. Intergcnetic Concurrence The third question, mentioned above as involved in a full statement of the problem of determination, is that of the relation of the determination of development to that of evolution ; that of the ' intergenetic ' relation of the two lines of progress, growth, and descent. We now find that the principles so far explained above, will, if they be true, afford an answer to this ques- tion also. The determination of the direction of evo- lution has been found to follow that of development. There is, therefore, in its great outline the ' concurrence ' which the theory of recapitulation supposes, and which it is reasonable to expect if the correlations already1 men- tioned between the two series are actually realized. The determination of the individual's development is by a process of adjustment to a more or less stable environment. The evolution of the race is throughout, in its great features, a series of adaptations to the same bionomic conditions. Moreover, by the establishing of a tradition throughout the life history of the higher forms, there is set up a series of modes of behaviour to which, as we have seen, both development and evolution, by the operation of organic and natural selection, tend ever more approxi- mately to conform. The two movements are, therefore, ' concurrent ' in a very well-defined sense. 1 Cf. Chap. XIII. § 5, below. 42 The Direction of Evolution The recognition of the essentially psychophysical na- ture of the evolution process becomes increasingly im- perative in the light of such a setting together of the subordinate problems in a single whole. We find as we advance a gradual shifting of the emphasis from the phys- ical to the mental. This is not only true in respect to the sort of utilities which ' fit ' variations subserve, but also in the very means of transmission itself. It is pointed out in the earlier work on Social and EtJiical Interpretations that, as tradition advances, and with it a corresponding in- crease in the plasticity of the young who are educated in this tradition, social transmission comes directly to super- sede the physical transmission of particular functions. Social transmission, however, is a process quite distinct from physical heredity. It has laws of its own.1 The dif- ference is so great that I have ventured to characterize social transmission as, in a sense, the means of the eman- cipation of mind from the limitations of biological prog- ress ; for by it there is secured a means of propagation of intelligent conduct without the negativing, swamping, and regressive effects of physical reproduction. Trans- mission by handing down, with imitative learning, is so different from transmission by physical heredity, that the series of conceptions which in the lower stages of evolu- tion hold for both body and mind together — where both are subject to the single law of congenital variation with natural selection — are no longer common to them, but a series of additional conceptions emerge which are com- parative principles principally in name. There are such differences in their operation in the two spheres respectively 1 An attempt to work out certain of these laws is made in Chap. II. of the work just cited. Genetic Analogies 43 that instead of calling them comparative principles, we may better denominate them 'analogies.' § 4. Genetic Analogies Of the analogies drawn from organic evolution, which spring up to vex the soul of the investigator in genetic things in other fields, many are aspects of what is called the 'biological analogy,' until now so much exploited in the social sciences. Certain aspects of it are treated in the papers which follow, and in the second volume of this series referred to just above. For example, the 'struggle for existence' is shown below (Chap. XV.) to take on three quite different forms even in the animal world, where it is a factor of direct importance in connection with the operation of natural selection. In the same place, the facts of conscious 'competition' and 'rivalry' are compared with those of biological struggle, with the result that only under certain conditions do they even show analogy with strug- gle for existence in the sense principally employed by Darwin and Wallace - - the struggle for food. So also, when we come to subject the conception of ' selection ' to a thorough analysis, we have distinctions to make which for- bid our using the biological conception in the mental and social spheres except under the very restricted limitation, namely, that the results of the selection in question nor- mally fall under the laws of physical reproduction and heredity for their conservation. Yet again, in the matter of conservation of type, with regression, where there is the question of the application of such a principle to mental transmission, we find that the mental products do not, in respect to their effectiveness for the future movement of 44 The Direction of Evolution social evolution or development, follow such a law — that they follow, moreover, a very different and in no wise anal- ogous law. The greater the variation in tradition, — the idea of the genius, the protest of a reformer, the new formula- tion of a scientific truth, - - the greater may be its effect ; while, by the law of biological regression, the great varia- tion, the sport, tends to be swamped by interbreeding, and the wider his departure from the mean the less his chance of impressing his characters upon posterity. The whole case is summed up in the statement made above, to the effect that social progress is no longer under the limitations set by physical heredity ; it is under the laws of mental process and organization.1 Some one may say, what is indeed quite true,2 that this progress is after all due to the operation of natural selec- tion, whereby the necessary plasticity required for the mind was selected and fixed ; but such a statement alone would be quite inadequate as an explanation. For when so much is said, what is gained ? So far may we go in the interpretation from the side of the physical ; but the meaning, I submit, of evolution in this direction is not to be found on the side of plasticity but on the side of mind -the accommodations which are effected on the basis of the plasticity. We now, in short, recognize that wonder- ful endowment which is correlated with plasticity in the psychophysical whole. The emphasis in the interpreta- tion of the twofold fact is not upon the process of the physical, but upon the events which are taking place in 1 See the remarks on history, and especially the criticism of Professor Karl Pearson, in Chap. XIX. § 7. 2 Professor Osborn, however, one of the original advocates of organic selec- tion, does not admit that plasticity has been acquired through natural selec- tion ; see the American Naturalist, Nov. 1897, cited in Appendix A. P reformism and Accommodation 45 the other aspect of the joint series. Hence we must draw directly upon the resources of that science, psychology, which makes the interpretation of the psychological move- ment its business. § 5. P reformism and Accommodation There is here what seems to me to be a fundamental error in the general theory of preformism ; and I shall state the point in a form in which it answers also a criti- cism of organic selection. It is said that the accommoda- tions and modifications which are effected by the individual organism simply show the unfolding of what the congenital endowment of the creature has made possible ; conse- quently, that these accommodations are sufficiently ac- counted for by the natural selection of the congenital variations which contribute to this endowment, so that there is nothing really additional or new in a theory which emphasizes these modifications.1 That this is a partial truth only it is easy to show. It becomes evident so soon as we come to see that the characters which the individual develops are a compound, as has been said above, of his hereditary impulses with the forces of his environment. If it were simply a matter of continued reproduction with- out determinate evolution from generation to generation, then it would make no difference what the individuals might undergo during their lives, provided the germ-plasm remained unaffected. But so soon as it becomes a question of descent with adaptations which are selected from a great many possible ones, in intergenetic correlation with the modifications of individuals, then the question as to which 1 Cf. the remarks on the relation of organic to natural selection in Chap. VIII. § 7. 46 The Direction of Evolution variations are to be perpetuated and accumulated can be answered only by undertaking an investigation of this correlation ; that is, by interpreting the actual accommoda- tions, intelligent and other, which the individuals make. The use made of the plasticity by the intelligence, there- fore, becomes the critically important thing for evolution theory, even though it assumes the presence of the plas- ticity itself. It may be said, indeed, quite truly, that this value of accommodation is implicit in the theory of natural selec- tion; for, according to that theory, there is continued selec- tion of certain fit individuals, and their fitness may consist in their being plastic or ' accommodating.' This is es- pecially true of the theory of Roux, which makes use of what he calls 'the struggle of the parts,' and of Weis- mann's ' intra-selection ' theory. Yet still the qualifica- tions of the fit individuals are not given in their plasticity, but they arise only in the course of development ; and they may take on many different forms. There may be alterna- tive ways in which the same plastic material or organism may adjust itself to the conditions of life. The same emergency may lead animals of common heredity and equal plasticity to make vital adjustments so different in kind that each may start a new line of evolutionary prog- ress. In fact, I think many cases of divergent evolution have actually begun in such a situation (cf. Chap. XIII. § 2, 3). How, then, is it possible to say that both these differing lines of descent are equally accounted for by the same degree of plasticity in the individuals who are their common progenitors ? Suppose two creatures born with the same degree of plasticity in respect to a certain function, but with differ- P reformism and Accommodation 47 ent correlations, or with differences in other characters which make their behaviour in effecting accommodations to the environment somewhat different. They adopt dif- ferent ways of using their plastic substance and both live, yet with considerable differences of habit and behaviour. These, if there be enough individuals of each sort, would carry on from generation to generation their respective habits of life ; tradition would spring up to set and confirm each group in its own way of life. And again there would be divergent or polytypic evolution as the result, although their original plasticity was the same. Here it is a ques- tion of the correlations of the plasticity, not merely the possession of it. In this case and the one just cited the actual development dominates evolution, not merely the pos- sible development.1 I am not able, therefore, to see great force in the contention of the preformists when they claim that the recognition of the variation by which a function is made possible in development supplies a sufficient theory of the course of the development, and also of its results in determining evolution. All this is notably true in the matter of mind, and in evolution into which a strain of conscious accommodation has entered. Let us say, for instance, that the female bird has a certain capacity for preferential choice among possi- ble males. This means nothing, unless she actually makes a choice. Then the physical characters of the offspring vary according as this male or that is chosen, and these go down to posterity. It is the result which is the evolu- tion, and it is conditioned upon the use made of the endow- 1 As Professor Poulton says, speaking of organic selection in general (see Appendix A), ' in this way natural selection would be compelled to act along a certain path ' — a strong and true statement. 48 The Direction of Evolution ment. We might as well say that a man is the cause of all the follies of his wayward son because he begot the son, as to say that natural selection is responsible for — or is an adequate explanation of — the results which spring from the accommodations of an organism, simply on the ground that the plasticity of the organism has survived by natural selection. Or, to take a case which more truly depicts the function of natural selection, we might as well say that the mother of Moses and the daughter of Pharaoh were the essential factors in the production of that great lawgiver's work, inasmuch as they warded off the dangers which threatened his life.1 But the endowments of Moses would have been quite ineffective, despite his sal- vation by the women, had not opportunities arisen for him to use his gifts. His actual performance is what counted in history ; and so it is with the humblest organism which accommodates itself to the environment, in so far as it makes effective contribution to the characters of the gen- erations which follow after it.2 1 Yet even this figure is allowing too much to natural selection, for the mother of Moses and the daughter of Pharaoh are, when considered as posi- tive agents, more analogous to the positive accommodations which fit the organism to survive ; it is these latter which save the creature's life. This case may suffice to show how impossible it is to put one's finger on any- thing positive to represent natural selection. Of course all will admit that the recognition of the actual facts and factors is the main thing — not the naming of them. Yet questions of the relative roles of the factors are important, both for interpretation and for the integrity of our logic. 2 Professor James Ward, art. 'Psychology,' in the Ency. Brit., Qth. ed., was one of the earlier writers who pointed out that organisms act very positively in adjusting themselves to their environment, selecting and even changing their life conditions by their own acts. He called this 'subjective selection,' and he has developed in a later publication, Naturalism and Agnosticism, the pos- sible influence this might be expected to have on the future course of evolution, uniting with it, however, the theory of the inheritance of acquired characters. Preformism and Accommodation 49 Returning to our main subject, after this digression, we may emphasize the necessity, now so often pointed out, of taking up, wherever possible, the psychophysical point of view, and of recognizing, as of equal importance with the biological, those factors and processes which, it may be, the psychologist alone is able to describe. No better instance can be cited — in illustration of many of the considerations •so far advanced — than the problem of the origin of instinct, of which certain phases are treated in the following pages. PART II THE METHOD OF EVOLUTION CHAPTER IV THE PLACE OF CONSCIOUSNESS IN EVOLUTION l § i. Professor Cope's Table IN a table in the Monist, July 26, Professor Cope gives certain positions on points of evolution, in two con- trasted columns, as he conceives them to be held by the two groups of naturalists divided in regard to hered- ity into Preformists and the advocates of Epigenesis. The peculiarity of the Epigenesis column is that it in- cludes certain positions regarding consciousness, while the Preformist2 column has nothing to say about conscious- ness. Being struck with this I wrote to Professor Cope -the more because the position ascribed to conscious- ness seemed to be the same, in the main, as that which the present writer has developed, from a psychological point of view, in the work on Mental Development. I 1 From Science, Aug. 23, 1895 (an informal communication). 2 Preformism is the view of those who hold that the individual organism is ' preformed ' in the germ and its development is in some way an unfolding of preformed parts. Epigenesis holds to a real growth or production of parts in the developing organism. Professor Cope holds with many Epigenesists that these newly acquired parts or functions are inherited (' Lamarckian ' heredity and evolution) ; and by the term ' Preformism ' he designates the opposed (Darwinian) view of heredity and evolution. The terms Lamarckism and Darwinism are used in the following pages to express this contrast. 5° Professor Copes Table learn from him that the table (given herewith) is not new ; but was published in the * annual volume of the Brooklyn Ethical Society in 1891 ': and the view which it embodies is given in the chapter on ' Consciousness in Evolution,' in his work, The Origin of tJie Fittest (1887). 1 . Variations appear in definite directions. 2. Variations are caused by the interaction of the organic being and its environment. 3. Acquired variations may be inherited. 4. Variations survive directly as they are adapted to changing environments (natural selection). 5. Movements of the organism are caused or directed by sensa- tion and other conscious states. 6. Habitual movements are de- rived from conscious experience. 7. The rational mind is de- veloped by experience through memory and classification. 1. Variations are promiscuous or multifarious. 2. Variations are ' congenital,' or are caused by mingling of male and female germ-plasms. 3. Acquired variations cannot be inherited. 4. Variations survive directly as they are adapted to changing environments (natural selection). 5. Movements of the organism are not caused by sensation or conscious states, but are a sur- vival through natural selection from multifarious movements. 6. Habitual movements are pro- duced by natural selection. 7. The rational mind is de- veloped through natural selection from multifarious mental activities. Apart from the question of novelty in Professor Cope's positions — and that one should have supposed them so can only show that one had read hastily, not having earlier become acquainted with Professor Cope's views - 1 wish to point out that the placing of consciousness, as a factor in the evolution process, exclusively in the Lamarckian column, appears quite unjustified. It is not a question of a causal interchange between body and mind. It is not likely that any naturalist would hold to an injection of energy in any form into the natural processes, 52 The Place of Consciousness in Evolution on the part of consciousness ; though, of course, Profes- sor Cope himself can say whether such a construction is true in his case.1 Many psychologists are about done with a view like that. The question at issue when we ask whether consciousness has had a part in the evolutionary process is really that as to whether we may say that the presence of consciousness — in the form say of sensations of pleasure and pain — with its correlative nervous or or- ganic processes, has been an essential factor in evolution ; and if so, further, whether its importance is because it is in alliance with the consciousness aspect that the organic aspect gets in its work. Or, to take a higher form of consciousness — does the memory of an object as having given pleasure modify the organism's reaction to that object the second time ? Such may be the case, even though it is only the physical basis of memory that has an efficient causal relation to the other organic processes of the animal. Conceiving of the function of consciousness, therefore, as in any case not that of a deus ex machina, the question at issue is whether it can have an essential place in the evolution process as the Darwinians construe that process. Professor Cope believes not.2 I believe that the place of consciousness may be the same — and may be the essential place that Cope gives it in his left-hand column and which is given to it in Mental Development — on the Darwinian view. I have argued briefly for this indifference to the particular theory one holds of heredity, in the volume referred to,3 reserving for later pages certain arguments in detail based upon the theory of the 1 In a reply made to this paper by Professor Cope he declares for such a view {American Naturalist, April, 1896, p. 342); see the next Chapter. 2 See his Primary Factors of Organic Evolution. 8 Chap. VII. Professor Copes Table 53 individual's personal relation to his social environment. The main point involved, however, may be briefly .sug- gested here, although, for the details of the influences now indicated, the other book may be again referred to (chapters on ' Suggestion ' and ' Emotion ').1 The writer there traces in some detail what other writ- ers also have lately set in evidence, i.e., that in the child's personal development, his ontogenesis, his life history, he works out a faithful reproduction of his social conditions. He is, from childhood up, excessively receptive to social suggestion ; his entire learning is a process of conforming to social patterns. The essential to this, in his heredity, is very great plasticity, cerebral balance and equilibrium, a readiness to overflow into the new channels which his social environment dictates. He has to learn everything for himself, and in order to do this he must begin in a state of great plasticity and mobility. Now, my point, put briefly, is that these social lessons which he learns for himself take the place largely of the heredity of par- ticular paternal acquisitions. The father must have been plastic to learn, and this plasticity is, so far as the evi- dence goes, the nervous condition of consciousness ; thus the father learned, through his consciousness, from his social environment. The child does the same. What he inherits is the nervous plasticity and the consciousness. He learns particular acts for himself; and what he learns is, in its main lines, what his father learned. So he is just as well off, the child of Darwinism, as if he were physical heir to the acquisitions which his father made. This process has been called ' Social Heredity,' seeing that the child really comes into possession of the details; 1 Also the later work, Social and Ethical Interpretations. 54 The Place of Consciousness in Evolution but he comes by them socially, through this process of social growth, rather than by direct physical inheritance. To show this in a sketchy way, we may take the last three points which Professor Cope places under the La- marckian column, the points which involve consciousness, and show how indeed they may still be true for the Dar- winian if he avail himself of the resource offered by ' Social Transmission.' This is done rather from interest in the subject than with any wish to controvert Professor Cope ; and it may well be that his later statements may show that he is able to accept the argument.1 § 2. The Origin of Adaptive Movements i. (5 of Cope's table.) 'Movements of the organism are caused or directed by sensation and other conscious states.' The point at issue here between the advocates of the two views of evolution would be whether it is necessary that the child should inherit any of the particular conscious states, or their special nervous dispositions, which the parent acquired in his lifetime, in order to secure through them the performance of the same actions by the child. I should say, no ; and for the reason — additional to the usual argu- ments of the Darwinians — that 'Social Transmission' is sufficient to secure the result. All we have to find in the child is the high consciousness represented by the ten- dency to imitate socially and so to absorb social copies, together with the law widely recognized by psychologists under the name of dynamogenesis — i.e., that the thought 1 In his reply, referred to above, Professor Cope fully accepts the fact called here ' Social Heredity.' The Origin of Adaptive Movements 55 of a movement tends to discharge motor energy into the channels as near as may be to those necessary for that movement.1 Given these two elements of endowment in the child, and he can learn anything that his father did, without inheriting any particular acts learned by the parent. And we must in any case give the child so much ; for the principle of dynamogenesis is a fundamental law in all organisms, and the tendency to learn by imitation, sugges- tion, etc., is present, as a matter of fact, with greater or less range, in man and in many other animals as well. The only apparent hindrance to the child's learning everything that his life in society requires would be just the thing that the advocates of Lamarckism argue for — the inheritance of acquired characters. For such inheritance would tend so to bind up the child's nervous substance in fixed forms that he would have less or possibly no plastic substance left to learn anything with. Such fixity occurs in the animals in which instinct is largely developed ; they have little power to learn anything new, just because their nervous systems are not in the mobile condition rep- resented by high consciousness. They have instinct and little else. Now, I think the Darwinian can account for instinct also, but that is beside the point ; the point to be made now is that, if Lamarckism were true, we should all be, to the extent to which both parents perform the same acts (as, for example, speech) in the condition of the crea- tures who do only certain things and do them by instinct. It may well be asked of the Lamarckian : What is it that is peculiar about the strain of heredity of certain creatures that they should be so remarkably endowed with instincts ? 1 Both of these requirements are worked out in detail in Mental Develop- ment. 56 The Place of Consciousness in Evolution Must he not say in substance that the nervous material of these creatures has been ' set ' in the creatures' ancestors ? Then why are not all constant functions thus set ? But the question of instinct is touched upon under the next point. 2. (6 of Cope's table.) ' Habitual movements are de- rived from conscious experience/ This may mean move- ments habitual to the individual or to the species in question. If it refers to the individual it may be true on either doc- trine, provided we once get the child started on the move- ment- -a point discussed in other connections.1 If, on the other hand, habitual movements mean movements charac- teristic of species, we raise the question of race habits, best typified in instinct. Agreeing that many race habits arose as conscious functions in the first place, and making that our supposition, again we ask : Can one who believes it still be a Darwinian ? It would appear that he could. The problem set to the Darwinian would not in this case differ from that which he has to solve in accounting for evolution generally ; it would not be altered by the pos- tulate that consciousness is present in the individual. He may say that consciousness is a variation, and what the individual does by it follows from this variation. And then what later generations do through their consciousness is all given with the variations which they constitute on the earlier variations.2 In other words, I do not see that the case is made any harder for the Darwinian by the pos- tulate that consciousness with its nervous correlate is a real factor. 1 Chap. VII. § 3; Chap. VIII. § 6; Chap. IX. § 2; Chap. XVII. § 5. 2 This is said by thorough-going preformists (Weismannists). But I think this case is much simplified by the hypothesis of ' organic selection ' (devel- oped in the following papers) of which the following paragraphs are a sum- mary statement (notably the lines now italicized). 77/6^ Origin of Adaptive Movements 57 Indeed, we may well go still further and say that the case is easier for him when we take into account the phenomenon of social heredity. In children, for example, there are great variations in mobility, plasticity, etc. — in short, in the ease of operation of social heredity as seen in the acquisition of particular functions. Children are noto- riously different in their aptitudes for acquiring speech, for example ; some learn faster, better, and more. Let us say that this is true in animal companies generally ; then the most plastic individuals will be preserved to do the advantageous tilings for which tJieir variations shoiv them to be the most fit. And tJie next generation will show an emphasis of just this direction in its variations. So the fact of social acquisition — the fact of acute use of conscious- ness in ontogeny — becomes an element in phylogeny, also, even on the Darwinian theory. Besides, when we remember that the permanence of a habit learned by one individual is largely conditioned by the learning of the same habits by others (notably of the opposite sex) in the same environment, we see that an enormous premium must have been put on variations of a social kind — those which brought different individuals into some kind of joint action or cooperation. Wherever this appeared, not only would habits be maintained, but new variations, having all the force of do7ible hereditary ten- dency, might also be expected. But consciousness is, of course, the prime variation through which cooperation is secured. All of which means, if it be true, that the rise of consciousness is of direct help to the Darwinian in accounting for race habits — notably those which are in some degree gregarious, cooperative, or social. 3. (7 of Cope's table.) ' The rational mind is developed 58 The Place of Consciousness in Evolution by experience, through memory and classification.' This, too, is true, provided the term ' classification ' has a mean- ing that psychologists agree to. So the question is again : Can the higher mental functions be evolved from the lower without calling in use-inheritance? So it seems. Here indeed it seems that the fact of social transmission is the main and controlling consideration. It is notorious how meagre the evidence is that a son inherits or has the pecul- iar mental traits of parents beyond those traits contained in the parents' own heredity. Galton has shown how rare a thing it is for artistic, literary, or other marked talent to maintain its strength in later generations. Instead, we find such endowments showing themselves in many individuals at about the same time, in the same communities, and under common social conditions. Groups of artists, musicians, literary men, appear together — as it were, a social out- burst. The presuppositions of genius — obscure as the sub- ject is — seem to be great power of learning or absorbing, marked gifts or proclivities of a personal kind which are not present in the parents but fall under the head of vari- ations ; and with these a social environment of high level in the direction of these variations. The details of the individual's development, inside of the general proclivity which he has, are determined by his social environment, not by his natural heredity. And no doubt the phylo- genetic origin of the higher mental functions — thought, self-consciousness, etc. — must have been similar.1 There is not any great amount of truth in the claim of Spencer that intellectual progress in the race requires the Lamarckian view. The level of culture in a community 1 Detailed account of the social factors involved in the evolution of these higher faculties is attempted in the two earlier volumes of this series. The Origin of Adaptive Movements 59 seems to be about as fixed a thing as moral qualities are capable of being, much more so than the level of individual endowment. This latter seems to be capricious or varia- ble, while the former proceeds by a regular movement and with a massive front. It would seem, therefore, that intel- lectual and moral progress is gradual improvement, through improved relationships on the part of the individuals to one another ; a matter of social accommodation, rather than of direct natural inheritance on the part of individuals. It is only a rare individual whose heredity enables him to break through the lines of social tissue and imprint his personality upon the social movement. And in that case the only explanation of him is that he is a variation, not that he inherited his intellectual or moral power. Furthermore, I think the actual growth of the individual in intellectual stature and moral attainment can be traced in the main to certain of the elements of his social milieu, allowing always a balance of variation in the direction in which he finally excels. So strong does the case seem for the social heredity view in this matter of intellectual and moral progress that I may suggest an hypothesis which may not stand in court, but which seems interesting. May not the rise of the social life be justified from the point of view of a second utility in addition to that of its utility in the struggle for existence as ordinarily understood, the second utility, i.e., of giving to each generation the attainments of the past which physical heredity is inadequate to transmit ? Whether we admit Lamarckism or confine ourselves to Darwinism, I suppose we may safely accept Galton's law of Regres- sion and Weismann's principle of Panmixia in some form. Now as social life advances we find the beginning of the 60 The Place of Consciousness in Evolution artificial selection of the unfit ; and so these negative prin- ciples begin to work directly in the teeth of progress, as many writers on social themes have recently made clear. This being the case, some other resource is necessary be- sides physical heredity. On my hypothesis it is found in the common social standards of attainment to which the individual is fitted to conform and to which he is com- pelled to submit. This secures progress in two ways : First, by making the individual learn wJiat the race has learned, thus preventing social retrogression, in any case ; and second, by putting a direct premium on variations which are socially available. Under this general conception we may bring the bio- logical phenomena of infancy, with all their evolutionary significance : the great plasticity of the mammal infant as opposed to the highly developed instinctive equipment of other young ; the maternal care, instruction, and example during the period of helplessness ; and the very gradual attainment of the activities of self-maintenance in condi- tions in which social activities are prominent or essential. All this stock of the evolution theory is available to confirm this view. And to finish where we began, all this is through that wonderful instrument of acquisition, consciousness ; for consciousness is the avenue of all social influences. CHAPTER V HEREDITY AND INSTINCT a § i. Romanes on Instinct IN his able posthumous work on Post-Darwinian Ques- tions, Heredity and Utility, the lamented G. J. Romanes sums up the evidence for the inheritance of acquired char- acters in the final statement that only two valid arguments remain on the affirmative side ; and to each of these argu- ments he has devoted considerable space. One of these arguments is from what he calls ' selective value,' and the other from the ' co-adaptations ' found in the instincts of animals. He says (p. 141): 'Hence there remain only the arguments from selective value and co-adaptation.' If we take the instincts as illustrating the application of the principle of ' selective value as well/ we may gather the evidence which Romanes was disposed to cling to, for the inheritance of acquired characters, into a single net, and inquire as to the need of resorting to the Lamarckian factor in accounting for the origin of instinct. I wish to suggest some considerations from the psychological side, which seem to me entirely competent to remove the force of these two arguments, and to show to that extent that the instincts can be accounted for without appeal to the hypoth- esis of 'lapsed intelligence,' as the use-inheritance theory, 1 Discussion (revised) following Professor C. Lloyd Morgan before the New York Academy of Sciences, Jan. 31, 1896; from Science, March 20, 1896. 61 62 Heredity and Instinct in its application to this problem of instinct, is called ; in other words, to show that Darwin, Romanes, and the Neo-Lamarckians are not right in considering instinct as ' inherited habit.' § 2. Instinct and Lamarckism: Co-adaptation The argument from co-adaptation in the case of instinct requires the presence of some sort of intelligence in an ani- mal species, the point being that since the coordination of muscular movements found in the instincts are so co- adapted they could not have arisen by gradual variation. Partial adaptations tending in the direction of an instinct would not have been useful ; and intelligence alone would suffice to bring about the coordinations which are too com- plex to be accounted for as spontaneous variations. These intelligent coordinations then become habits by repetition in the individual and show themselves in later generations as inherited habits due to 'lapsed intelligence.' Assum- ing, then, with Romanes — whom we may cite as a very recent upholder of the view — the existence of some intel- ligence in a species antecedently to the appearance of the instinct in question, we may be allowed that supposition and resource. I. But now let us ask how the intelligence brings about coordinations of muscular movement. The psychologist is obliged to reply : Only by a process of selection (through pleasure, pain, experience, association, etc.) from certain alternative complex movements which are already pos- sible to the individual animal. These possible combina- tions are already there, born with him, or resulting from his previous habits. The intelligence can never, by any possibility, create a new movement ; nor effect a new com- Instinct and Lamarck ism : Co-adaptation 63 bination of movements, if the apparatus had not been made already trained by actual use for the combination which is effected.1 So far as there are modifications in the grouping, even these are very slight functional varia- tions from the uses already made of the muscles involved. This point is no longer subject to dispute ; for pathological cases show that unless some adequate idea of a former movement made by the same muscles, or some other idea which stands for it by association, can be brought up in mind, the intelligence is helpless. Otherwise it cannot only not make new movements ; it cannot even repeat old habitual movements. So we may say that intelligent adaptation does not create coordinations ; it only makes functional use of coordinations which were alternatively present already in the creature's equipment.2 Interpreting this in terms of congenital variations, we may say that the variations which the intelligence uses are alternative possibilities of muscular movement. But these are exactly the variations which instinct uses, except that in instinct they are not alternative. That this is so, indeed, lies at the basis of the claim that instinct is inher- ited habit. The real difference in the variation involved in the two cases is in the connections in the brain whereby in 1 Professor Cope has understood this to mean that consciousness can select out or direct the combination. This is accomplished, in my opinion, by a process analogous to natural selection, i.e., the survival of useful movements from overproduced movements, a process called ' functional selection ' in Alental Development, formulated in an earlier paper, ' The Origin of Volition,' reprinted in Fragments in Philosophy and Science (1902); see also the references given, p. 56, note I, above. 2 When we strain our muscles to accomplish a new act of skill, we are aiming to use the apparatus in new ways by a selection from possible combi- nations; and even when we learn to use disused muscles, as those of the ear, we are only aiming to stir up possible connections not before actively used. 64 Heredity and Instinct instinct the muscular coordination is brought into play directly by a sense stimulation ; while in intelligence it is brought into play indirectly, i.e., through association of brain processes, with selection of fortunate combinations. Now this difference in the central brain connections is, I submit, not at all a great one, relatively speaking, and it might well be due to spontaneous variations. The point of view which holds that great co-adaptations of the muscles have to be acquired all at once by the creature is quite mistaken. § 3. Instinct and Lamarckism : 'Selective Value* The same class of considerations refutes the argument from ' selective value.' a This argument holds that the instinct could not have arisen by variations alone, with natural selection, since partial coordinations tending in the direction of the instinct would not have been useful ; so the creatures with such partial coordinations merely would have been killed off, and the instinct could never have reached maturity ; only variations which are of sufficient value or utility to be ' selective ' would be kept alive and perfected. But we see that the intelligence which is appealed to, to take the place of instinct and to give rise to it, uses just these partial variations which tend in the direction of the instinct ; so the intelligence supplements such partial coor- dinations, makes them functional, and so keeps the creature alive. This prevents the 'incidence of natural selection,' to use a phrase of Professor Lloyd Morgan's. So the sup- position that intelligence is operative turns out to be just 1 In my opinion ' selective value ' is equivalent simply to ' utility ' : any amount of utility is ' selective.' Social Transmission and Instinct 65 the supposition which makes the use-hypothesis unneces- sary. Thus kept alive, tJie species has all the time necessary to perfect tJie variations required by a complete instinct)- And when we bear in mind that the variation required is, as was shown above, not on the muscular side to any great extent, but in the central brain connections, and is a slight variation for functional purposes at the best, the hypothesis of use-inheritance becomes, to my mind, not only unneces- sary, but quite superfluous. § 4. Social Transmission and Instinct II. There is also another great resource open to the Darwinian in this matter of instinct ; also a psychological resource. Weismann and others have shown that the influence of animal intercourse, seen in maternal instruc- tion, imitation, gregarious cooperation, etc., is very impor- tant. Wallace dwells upon the actual facts which illustrate the 'imitative factor,' as we may call it, in the personal development of young animals. It is argued above that Spencer and others are in error in holding that social progress demands the use-inheritance hypothesis;2 since the socially-acquired actions of a species, notably man, are socially handed down, giving a sort of ' social transmission ' which supplements physical heredity. And when we come to inquire into the actual mechanism of imitation on the part of a young animal, we find much the same sort of function involved as in intelligent adaptation. The impulse to imitate requires the ability to act out for him- 1 Italicized in this reprinting (as is done in the preceding paper) as antici- pating the full statement of the theory of ' Organic Selection ' later on. 2Cf. Science, Aug. 23, 1895, *ne preceding paper; summarized in Nature, Vol. LIL, 1895, P- 627. F 66 Heredity and Instinct self certain of the actions which the animal sees, to make the sounds which he hears, etc. Now this involves con- nections of the centres of sight, hearing, etc., with certain muscular coordinations. If he have not the coordinations, he cannot imitate ; just as we saw above is the case with intelligence, if the creature have not the function ready, he cannot perform it intelligently. Imitation differs from intelligence in being a general form of coordinated adapta- tion, while intelligence involves a series of special forms.1 But both make use of the apparatus of coordinated move- ment. So we find, as an actual fact generally agreed upon, that by imitation the little animal picks up directly the example, instruction, mode of life, etc., of his private family circle and of his species.2 This, then, enables him to use effectively, for the purposes of his life, the coordina- tions which become instincts later on in the life of the species ; and again we have here two points which directly tend to neutralize the arguments of Romanes from ' selec- tive value' and 'co-adaptation.' The co-adaptations may be held to be gradually acquired, since the coordinations of a partial kind are utilized by the imitative functions before they become instinctive. And the law of ' selective value ' does not get application, since the imitative func- tions, by using these muscular coordinations, supplement them, secure accommodations, keep the creature alive, prevent the ' incidence of natural selection, and so give the species all the time necessary to get the variations required for the full instinctive performance of the function. 1 That they are really the same in type and origin is argued in detail in the work Mental Development. 2 Largely along the line of his native impulses, as recent researches have shown (1902). Social Transmission and Instinct 67 III. These positions are illustrated in a very fortunate way by the interesting cases reported by Professor LI. Mor- gan in his instructive discussion. He cites the beautiful observation that his young chicks had the instinct to drink by throwing their heads up in the air, etc., but that it came into action only after they had the taste : of water by accident or by imitating the old fowl. As LI. Morgan says, the * incidence of natural selection' is prevented by imitation or instruction or intelligent adaptation (in cases where experience is required). So, in this instance, the instinct of drinking, which only goes so far as a connection of certain muscular coordinations with the sense of taste (wet bill) is made effective for the life inter- ests of the chick. TJins kept alive tJie species has plenty of time — in case it should be necessary — to get a connection established also between the sight centre and the same coordination of movements ; so that future chicks may be born with a capacity for drinking when water is seen only, without waiting for instruction, a fortunate accident, or an example to imitate. So we may imagine creatures, whose hands were used for holding on with the thumb and fingers on the same side of the object held, to have first discovered, under stress of circumstances and with varia- tions which permitted the further adaptation, how to make intelligent use of the thumb for grasping opposite to the fingers, as we now do. Then, let us suppose that this proved of such utility that all the young that did not do it were killed off ; the next generation following would be intelligent or imitative enough to do it also. They would 1 Or other form of stimulation from getting the bill wet (this in view of a later discussion, as to just what the stimulation is, in Science} — reprinted by Mills in Nature and Development of Animal Intelligence, pp. 277 ff. 68 Heredity and Instinct use the same coordinations intelligently or imitatively, prevent natural selection getting into operation, and so instinctive 'thumb-grasping* might be waited for indefi- nitely by the species and tJien arise by accumulated vari- ation, altogether apart from use-inheritance. We may say, therefore, that there are two great kinds of influence, each in a sense hereditary: there is pJiysical heredity by which variations are congenitally transmitted with original endowment, and there is ' social heredity ' by which functions socially acquired (i.e., imitatively, covering all the conscious acquisitions made through intercourse with other animals) are socially transmitted. The one is phylogenetic ; the other, ontogenetic. But these two lines of transmission are not separate nor are they un- influential on each other. Congenital variations, on the one hand, are kept alive and made effective by their con- scious use for intelligent and imitative accommodations in the life of the individual ; and, on the other hand, intelligent and imitative accommodations become congenital by further progress and refinement of variation in the same lines of function as those which their acquisition by the individual called into play. But there is no need in either case to assume the Lamarckian factor. The intelligence holds a remarkable place in each of these categories. It is itself, as we have seen, a con- genital variation ; but it is also the great agent of the individual's personal accommodations both to the physical and to the social environment. The emphasis, however, of the first of these two lines of transmission gives prominence to instinct in animal species, and that of the other to the intelligent and social cooperation which goes on to be human. The former Instinct and Intelligence 69 represents a tendency to brain variation in the direction of fixed connections between certain sense-centres and certain groups of coordinated muscles. This tendency is embodied in the white matter and the lower brain centres. The other represents a tendency to variation in the direc- tion of alternative possibilities of connection of the brain centres with the same or similar coordinated muscular groups. This tendency is embodied in the cortex of the hemispheres. I have cited ' thumb-grasping ' because we may see in the child the anticipation, by intelligence and imitation, of the use of the thumb for the adaptation which the simian probably gets by instinct or accident, and which I think an isolated and weak-minded child, say, would also come to acquire by instinct or accident when his apparatus became sufficiently matured. § 5. Instinct and Intelligence IV. Finally there are two general bearings of the position taken above regarding the place and function of intelligence and imitation which may be briefly noted. i. We reach a point of view which gives to organic evolution a sort of intelligent direction after all ; for of all the variations tending in the direction of an instinct, but inadequate to its complete performance, only those will be supplemented and kept alive which the intelligence ratifies and uses for the animal's individual accommodations. The principle of selection applies strictly to the others or to some of them. So natural selection eliminates the others ; and the future development of instinct must at each stage of a species evolution be in the directions thus ratified by intel- ligence. So also with imitation. Only those imitative 70 Heredity and Instinct actions of a creature which are useful to him will survive in the species ; for in so far as he imitates actions which are injurious, he will aid natural selection in killing himself off. So intelligence, and the imitation which copies it, will set the direction of the development of the complex instincts even on the Darwinian theory ; and in this sense we may say that consciousness is a 'factor' without resort- ing to the vague postulates of 'self-adaptation,' 'growth- force,' 'will-effort,' etc., which have become so common of late among the advocates of the new vitalism. 2. The same consideration may give the reason in part that instincts are so often coterminous with the limits of species. Similar creatures find similar uses for their intelligence, and they also find the same imitative actions to be to their advantage. So the interaction of these conscious factors with natural selection brings it about that the structural definition which characterizes species, and the functional definition which characterizes instinct, largely keep to the same lines. CHAPTER VI HEREDITY AND INSTINCT (II.)1 IN the preceding chapter I argued from certain psycho- logical truths for the position that two general principles recently urged by Romanes for the Lamarckian, or ' inher- ited habit/ view of the origin of instincts do not really sup- port that doctrine. These two principles are those cited by Romanes under the phrases respectively 'co-adaptation' and 'selective value.' In the case of complex instincts these two arguments really amount to but one, so long as we are talking about the origin of instinct. And the one argument is this : that partial co-adaptations in the direc- tion of an instinct are not of selective value ; hence instinct could not have arisen by gradual partial co-adaptive varia- tions, but must have been acquired by intelligence and then inherited. This general position is dealt with in the earlier chapter. It will be remembered, however, that the force of the refu- tation of the Lamarckian's argument on this point depends on the assumption, made in common with him, that some degree of intelligence or imitative faculty is present before the completion of the instinct in question. To deny this is, of course, to deny the contention that instinct is 'lapsed intelligence,' or ' inherited habit.' To assume it, however, opens the way for certain further questions, which I may now take up briefly, citing Romanes by preference as before. 1 Conclusion of the preceding paper, printed separately in Science, April 10, 1896. 71 72 Heredity and Instinct § i. Duplicated Functions I. The argument from 'selective value' has a further and very interesting application by Romanes. He uses the very fact upon which the argument in the earlier pages is based to get further support for the inheritance of habits. The fact is this, that intelligence may perform the same acts that instinct does. So granting, he argues, that the intelligent performance of these acts comes first in the species' history, this intelligent performance of the actions serves all the purposes of utility which are claimed for the instinctive doing of the same actions. If this be true, then variations which would secure the instinctive performance of these actions do not have selective value, and so the species would not acquire them by the opera- tion of natural selection. By the Lamarckian theory, how- ever, he concludes, the habits of intelligent action give rise to instincts for the performance of the same actions which are already intelligently performed, the duplicate functions often existing side by side in the same creature.1 This is an ingenious turn, and raises new questions of fact. Several things come to mind in the way of comment. First. It rests evidently on the state of things required by my earlier argument against the Lamarckian claim that co-adaptation could not have been gradually acquired by variation ; the state of things which shows the intelli- gence preventing the ' incidence of natural selection ' by supplementing partial co-adaptation. Romanes now as- sumes that intelligence prevents the operation of natural selection on further variations, and so rules out the origin 1 op. cit., pp. 74-81. Duplicated Functions I v) of instinct through that agency ; or, put differently, that actions which are of selective value when performed intelli- gently are not afterwards of selective value when performed instinctively. But this seems in a measure to contradict the argument which is based on co-adaptations (examined in the earlier pages), i.e., that instincts could not have arisen by way of partial co-adaptations at all. In other words, the argument from ' co-adaptations ' asserts that the partial co-adaptations are not preserved, being useless ; that from selective value asserts that they are preserved and, with the intelligence thrown in, are so useful as to be of selective value. We have seen that the latter position is probably the true one ; but that the inheritance of acquired characters is then, through this union of variation with intelligence, made unnecessary. Second. Assuming the existence side by side in the same creature of the ability to do intelligently certain things that he also does instinctively, it is extraordinary that Romanes should then say that the instinctive reflexes have no utility additional to that of the intelligent per- formance. On the contrary, the two sorts of performance of the same action are of very different and each of extreme utility. Reflex actions are quicker, more direct, less variable, less subject to inhibition, more deep-seated or- ganically, and thus less liable to derangement. Intelligent actions — the same actions in kind — are, besides the points of opposition indicated, and by reason of them, more adaptable. Then there is the remarkable difference that intelligent actions are centrally stimulated, while reflex actions are peripherally stimulated. We cannot go into all these differences here ; but the case may be made strong enough by citing certain divergencies between the two 74 Heredity and Instinct sorts of performance, with illustrations which show their separate utilities. 1. Reflex and instinctive actions are less subject to derangement. Emotion, shock, temporary ailment, hesita- tion, aboulia, lack of information, etc., may paralyze the intelligence ; and instinct and reflex action may keep the creature alive in the meantime. What keeps dogs alive, and able to meet the demands made upon them, after extended ablation of the brain cortex ? 2. Reflexes are quicker. Suppose instead of winking reflexly when a foreign body approaches the eye, I waited to see whether it was near enough to be dangerous, or even shut my eye as quickly as I could ; I should join the ranks of the blind in short order. 3. Reflex actions are more deep-seated, and arose ge- netically first. What keeps the infant alive and in touch with his environment before the voluntary fibres are de- veloped ? This genetic utility alone would seem critical enough to justify most of the genuine reflexes of the organism, — supplemented, of course, in the human case, by the mother ! 4. Intelligent actions are centrally stimulated. This means that brain processes release the energy which goes out in movement, and that something earlier must stimu- late the brain processes. This something is association in some shape between present stimulating agencies in the en- vironment and memories with pleasures or pains. In other words, certain central processes intervene between the outside stimulus and the release of the energies of move- ment. In reflexes, however, no such central influence intervenes. The stimulus in the environment passes directly — is reflected — into the motor apparatus. Hence Duplicated Functions 75 the reflex is more direct, undeviating, invariable, sure. For example, research has recently proved that involun- tary movements may be produced in a variety of normal circumstances, and in hysterical subjects, when the stimu- lation is too weak, or intermittent, or unimportant, to be perceived at all. 5. Experiments show that the energies of the two are not quantitatively the same. Mosso and Waller have shown that the muscles do work under electric stimulation after being quite exhausted for voluntary action, and vice versa. There may be exchanges of energy between the two circuits involved, and this may give the animal in- creased force in this reaction or that. 6. The intelligence could not attend to the necessary functions of life without the aid of reflexes — to say nothing of the luxuries of acquisition. So not to have the reflexes would prevent the growth of the intelligence. For exam- ple, suppose we had to walk, wink, breathe, swallow, brush away flies and mosquitoes, etc., all by voluntary attention to the details and all at the same time. While chasing flies we should forget to breathe ! And when should we have a moment's time to think ? In this line it is in order to cite the experiments made on 'distraction,' which show that most of the common adaptations of life can go on by reflex and subconscious processes while the intelligence is otherwise occupied.1 7. Attention and voluntary intermeddling with reflex and instinctive functions tend to destroy their efficiency, bringing confusion and all kinds of disturbance. The foregoing are all psychological facts, and more might be added showing that instinct has its own great 1 See Binet, Alterations of Personality, Part II., Chap. V. (Eng. trans.). 76 Heredity and Instinct utility even when the intelligence may perform the same actions in its own fashion. So it remains in each case to find out this utility and appraise it, before we say that it is not a reason for survival. It would seem that reflexes are of supreme importance and value ; and if so, then natural selection may be appealed to, to account for them. So about all that remains of this argument of Romanes is the contribution which it makes to the refuta- tion of his other one — from co-adaptations. The assump- tion of intelligence disposes of both the arguments, for the intelligence supplements slight co-adaptations and so makes them effective and useful ; but it does not keep them from serving other utilities, as instincts, reflexes, etc., by further variation. § 2. Reflexes and Imitation II. There is still another very interesting question also to be settled by fact. Romanes and others cite simple reflexes as well as complex instincts as giving illustrations of the application of the principle of ( inherited habit ' or * lapsed intelligence'; and the cases which Romanes lays great stress on are the reflex actions of man's withdrawal of the leg from irritation to the soles, and the brainless frog's balancing himself.1 The Neo-Lamarckian theory requires the assumption of intelligence for all of these. I have shown that granting the intelligence, that is just the assumption which in many cases enables us to discard the Lamarckian factor. But we may ask : Is the intelli- gence necessary for all reflexes ? The question is too involved for treatment here ; but 1 Passage cited above from Romanes. Reflexes and Imitation 77 the assumption that intelligence is necessary in any sense which makes the conscious voluntary performance of the action always precede the reflex performance in evolution is difficult to defend. For all that we know of the brain seat of voluntary intelligence, of the use of means to ends, etc., indicates that such action is dependent upon the pres- ence of the great mass of organic reflex processes which go on below the cortex. Complex associative processes must be genetically (and phylogenetically) later than the simple reflex processes, which, as has been intimated above, they presuppose. But the more liberal definition of intelligence, which makes it include all kinds of conscious processes — the assumption of intelligence being that simply of con- scious process of some kind — that is a different matter. This supposition seems to be necessary on either theory of instinct, as is argued above ; for if we do not assume it, then natural selection is inadequate, as say Romanes and Cope ; but if we do assume it, then the inheritance of acquired characters is unnecessary. On this simpler defi- nition of intelligence, however, we find certain states of consciousness, of which imitation is the most promi- nent example, serving nature a turn in the matter of evolution. On this wider definition of intelligence the difference between intelligent (e.g., imitative) action and instinctive reflex action is much greater than that pointed out in detail above between voluntary and reflex action. A word to show this may be allowed here, since it makes yet stronger the case against the special argument from selec- tive fitness, which this paper set out to examine. The differences between imitative action and reflex or 78 Heredity and Instinct instinctive action are not just those which we have found between voluntary and reflex actions. Imitation seems to be a native impulse ; and in so far it seems to be, like the instincts, stimulated from the periphery. But it has a further point of differentiation from the special instincts and reflexes in that it is what has been called a ' circular ' reaction, i.e., it tends to reproduce its stimulus again, — the movement seen, the sound heard, etc. There is always a certain comparability or similarity, in a case of conscious imitation, between the thing imitated and the imitator's result ; and the imitation is unmistakably real in propor- tion as this similarity is real. We may say, therefore, that consciously imitative actions are confined to those certain channels of discharge with produce results comparable with the 'copy' which is imitated. But the special instincts and reflexes are not so. They show the greatest variety of arrangement between the stimulus and the movement which results from it — arrange- ments which have grown up under the law of survival. They represent, therefore, special utilities which direct conscious imitation in each case, by the individual creature, does not secure ; while conscious imitation represents a general utility more akin to that which we have found in volun- tary intelligence. If this be so, then we have to say that conscious imita- tion, while it prevents the incidence of natural selection, as has been seen, and so keeps alive the creatures which have no instincts for the performance of the actions required, nevertheless does not subserve the utilities which the special instincts do, nor prevent them from having the survival value of which Romanes speaks. Accordingly, on the more general definition of intelligence, which Reflexes and Imitation 79 includes in it all conscious imitation, use of maternal instruction, and that sort of thing (the vehicle of ' social transmission') — no less than on the more special defini- tion spoken of above — we still find the principle of natural selection operative in the production of instincts and reflexes.1 1 This and the two preceding papers in Science (and in this work) are not intended as more than preliminary statements of results thrown into the form of criticisms of particular views (i.e.) Romanes' and Cope's). It is for this reason that further reference is not made to the literature of the subject. CHAPTER VII PHYSICAL HEREDITY AND SOCIAL TRANSMISSION1 THE main question at issue is the relation of conscious- ness or intelligence to heredity, another matter, that of the relation of consciousness to the brain, being so purely speculative that it is merely touched upon at the end of this discussion. Professor Cope 2 says : ' There is no way short of super- natural revelation by which mental education can be accom- plished other than by contact with the environment through sense-impressions, and by transmission of the results to sub- sequent generations. The injection of consciousness into the process does not alter the case, but adds a factor which necessitates the progressive character of evolution.' Both of these sentences may be accepted, except the assertion of transmission by means of Lamarckian inheritance, which the presence of consciousness seems to render unnecessary. Using the more neutral word ' conservation ' instead of 'transmission,' I may refer to three points on which Pro- fessor Cope criticises my views : first, the conservation of intelligent acquisitions from generation to generation ; second, ' the progressive character of evolution ' ; and third, ' mental education ' or acquisition. 1 From the American Naturalist, May, 1896, p. 422 ; in formal reply to Professor Cope. 2 American Naturalist, April, 1896, p. 343. 80 The Transmission of Intelligent Acquisitions 81 § I. The Transmission of Intelligent Acquisitions First, accepting the statement of the fact of mental acqui- sition or ' selection through pleasure, pain, experience, asso- ciation, etc.' (on which, see third below), Professor Cope cites the second paper (Science, March 20), in which I hold that consciousness makes acquisitions of new move- ments by such selections. He then says --if so, then I admit the Lamarckian factor. But not at all; it is just the point of the article to refute Romanes by showing that adaptation by intelligent selection makes the Lamarckian factor unnecessary. And in this way, i.e., this sort of adapta- tion on the part of a creature keeps tJiat creature alive by supplementing his reflex and instinctive actions, so prevents tJie operation of natural selection in his case, and gives the species time to get congenital variations in the lines that have thus proved to be useful (see cases cited).1 Further- more, all the resources of ' social transmission ' — the hand- ing down of intelligent acquisitions by parental instruction, imitation, gregarious life, etc. — come in directly to take the place of the physical inheritance of such adaptations. This influence Professor Cope, it is good to see, admits ; although in admitting it, he does not seem to see that he is practically throwing away the Lamarckian factor. For instead of limiting this influence to human progress, we have to extend it to all animals with gregarious and family life, to all creatures that have any ability to imitate, and finally to all animals which have consciousness sufficient to enable them to make conscious adaptations themselves ; for such creatures will have children able to do the same, and it is unnecessary to say that the children must inherit 1 Italics in the original paper. G 82 Physical Heredity and Social Transmission what their fathers did by intelligence, when they can do the same things by their own intelligence. As a matter of fact, Professor Cope is exactly the biologist to whose Lamarck- ism this admission is, so far as I can see, absolutely fatal ; for he more than many others holds that accommodations all through the biological scale are secured by consciousness.1 If so, then he is just the man who is obliged to extend to the utmost the possibility of the transmission also of these accommodations by means of intelligence, which, it appears, rules out the need of their transmission by physical heredity. At any rate, he is quite incorrect in saying that 'he [I] both admits and denies Lamarckism.' To this form of argument Professor Cope appears to pre- sent no objection except one drawn from analogy. He says : ' I do not see how promiscuous variation and natural selec- tion alone can result in progressive psychic evolution more than in structural evolution, since the former is conditioned by the latter/ As to the word ' progressive,' that question is taken up below ; but as to the analogy with structural evolution, two answers come to mind. In the first place, Professor Cope is one of the biologists who hold that all structural evolution is secured by direct conscious accom- modations. He says : ' Mind determines movements, and movements have determined structure or form.' If this be true, how can psychic be conditioned by structural evolu- tion ? Would not rather the structural changes depend upon the psychic ability of the creature to effect accommo- dations ? And then, second, at this point Professor Cope assumes the Lamarckian factor in structural evolution. Later on he makes the same assumption when he says : 1 And in this he is no doubt right ; see Chapters VII. and IX. of Mental Development. The Transmission of Intelligent Acquisitions 83 ' But since the biologists have generally repudiated Weis- mannism,' etc. If this means Darwinism, my impression is that even on the purely biological side, the tendency is the other way. Lloyd Morgan has pretty well come over ; Romanes took back before he died many of his arguments in favour of the Lamarckian factor ; and quite recently a paleontologist, Professor Osborn, — if he is correctly re- ported in Science, April 3, 1896, p. 530, — argues against Professor Cope on this very point with very much the same sort of argument as this which is made here.1 Yet Professor Cope will agree with me that this sort of argu- mentum ex autoritate is not very convincing. But Professor Cope goes on to say that I ' both admit and deny Weismannism ' ; on the ground that ' his [my] denial of inheritance only covers the case of psychological sports.' But the connection is not evident. If Professor Cope means denial of the inheritance of acquired charac- ters, then it is denied equally of sports and of other crea- tures; but it is not denied that the native 'sportness' (!) of sports tends to be transmitted. In my view the ' mas- siveness of front ' which social progress shows (and which Professor Cope accepts), shows that in social transmission the individual is usually swamped in the general movement, 1 Since this was written Professor Osborn has read a paper which confirms the statement of the text. Professor Osborn's expression ' ontogenic vari- ations ' i.e., those brought out by ' environment (which includes all the atmospheric, chemical, nutritive, motor, and psychical circumstances under which the animal is reared) ' seems to make these adaptations after all constitutional. As Professor Osborn says, this will not do for all cases ; and I think it will not do for instinct, where constitutional variations without the aid of consciousness would not suffice (as Romanes says) to keep the animal alive while correlated variations were being perfected. But it seems to answer perfectly where intelligent or other accommodations supplement the constitutional variations in the species. See Appendix A, I. 84 Physical Heredity and Social Transmission as the individual sport is in biological progress. As a matter of fact, however, the analogy from ' sports ' which Professor Cope makes does not strictly hold. For the social sport, the genius, is sometimes just the controlling factor in social evolution. And this is another proof that the means of transmission of intelligent adaptations is not physical heredity alone, but that they are socially handed down. It is difficult to see what Professor Cope means by saying that I * admit and deny Weismannism,' for I have never discussed Weismannism at all. I believe in the Neo-Darwinian position plus some way of finding why variations count in what seem to be determinate directions ; and for this latter the way now suggested appears better than the Lamarckian way. With many of the biologists (e.g., Professor Minot) I see no proof of Weismannism (and protest mildly against being sorted with Mr. Benjamin Kidd!); yet I have no competence for such purely bio- logical speculations as those which deal in plasms ! § 2. Progressive Evolution Second, the question as to how evolution can be made 'progressive.' Professor Cope thinks only by the theory of ' lapsed intelligence ' or ' inherited habit ' ; for admitting that the intelligence makes selections, then they must be inherited, in order that the progress of evolution may set the way the intelligence selects. But suppose we admit intelli- gent selection (even in the way Professor Cope believes), still there are two influences at work to keep the direction which the intelligence selects apart from the supposed direct inheritance. There is that of social handing down by tradition, etc., the social transmission which has been above spoken of ; and besides there is the survival by natural The Selective Process in Accommodation 85 selection of those creatures having variations which intelligence can use. This puts a premium on these varia- tions and their intelligent use in following generations. Suppose, for instance, a set of young animals some of which have variations which intelligence can use for a particular adaptation, thus keeping these individuals alive, while the others which have not these variations die off ; then the next generation will not only have the same vari- ations which intelligence can use in the same way, but will also have the intelligence to use the variations in the same way, and the result will be about the same as if the second generation Jiad inherited the adaptations directly. The direction of the intelligent selection will be preserved in future generations. I think it is a good feature of Pro- fessor Cope's theory that he emphasizes the intelligent direction of evolution, and especially that he does it by appealing to the conscious accommodations of the creatures themselves ; but just by so doing he destroys the need of the Lamarckian factor. Natural selection eliminates all the creatures which have not the intelligence and the vari- ations which the intelligence can use ; those are kept alive which have both the intelligence and the variations. They use their intelligence just as their fathers did, and besides get new intelligent accommodations, thus aiding progress again by further intelligent selection. What more is needed for progressive evolution ? ] § 3. The Selective Process in Accommodation Third. We come now to the third point, — the method of intelligent selection, — and on this point Professor Cope !I keep to 'intelligent' accommodations here; but the same principle applies to all adjustments made in individual development. 86 Physical Heredity and Social Transmission does not understand my position, I think. I differ from him both in the psychology of voluntary accommodations of movement and in the view that consciousness is a sort of force directing brain currents in one way or another (for nothing short of a force could release or direct brain cur- rents). The principle of dynamogenesis was cited in this form, i.e.) 'the thought of a movement tends to discharge motor energy into the channels as near as may be to those necessary for that movement' (above p. 55-56). This prin- ciple covers two facts. First, that no movement can be voluntarily carried out which has not itself been performed before and left traces of some sort in memory. These traces must come up in mind when its performance is again in- tended.1 And second (and in consequence of this), that no act, whatever, can be performed by consciousness by will- ing movements which have never been performed before. It follows that we cannot say that consciousness, by select- ing new adjustments beforehand, can make the muscles perform them. The most that many recent psychologists are inclined to claim is that by the attention one or other of alternative movements which have been performed before (or combinations of them) may be performed again ; in other words, selection is among old alternative move- ments. But this is not what Professor Cope seems to mean, nor what his theory requires. His theory requires the acquisition of new movements, new accommodations to 1 This is formulated in the principle of ' Kinoesthetic Equivalents,' defined in the writer's Diet, of Philos. and Psycho! . as follows : ' any mental content of the kinsesthetic order [i.e., representing earlier experiences of movement] which is adequate to secure the voluntary performance of a movement. . . . The term equivalent is recommended to sum up the formulation that unless a kinaesthetic content "equivalent" to a movement be reinstated in conscious- ness the voluntary performance of that movement is impossible.' The Selective Process in Accommodation 87 environment, by a conscious selection beforehand of certain movements which are then and for tJie first time carried out by tJie muscles)- It may very justly be asked : If his view be not true, how then can new movements which are adaptive, ever be learned at all ? This is one of the most important ques- tions, in my view, both for biologists and for psycholo- gists; and the recent work on Mental Development is, in its theoretical portion (Chap. VII. ff.), devoted mainly to it, i.e., the problem of ontogenic accommodation. We cannot go into details here, but it may suffice to say that Spencer (and Bain after him) laid out what seems to be, with cer- tain modifications urged in that work, the only theory which can stand in court. Its main thought is this, that all new movements which are adaptive or ' fit ' are selected from overproduced movements, or movement variations, just as organisms are selected from overproduced variations by the natural selection of those which are fit. This process, thus conceived, is there called ' functional selection,' a phrase which emphasizes the fact that it is the organism which secures from all its overproduced movements those which are adaptive and beneficial. The part which the intelli- gence plays 'through pleasure, pain,2 experience, associ- ation,' etc., is to concentrate the energies of movement upon the limb or system of muscles to be used and to hold the adaptive movement, ' select ' it, when it has once been struck. In the higher forms of mind both the concentra- tion and the selection are felt as acts of attention. 1 ' Conscious states do have a causal relation to the other organic pro- cesses.' I do not find, however, that Professor Cope has made clear just how in his opinion the 'selection' by consciousness works. 2 The role of pleasure and pain, in regulating the discharges by a 'circular reaction,' is spoken of below, Chap. VIII. § 6. 88 Physical Heredity and Social Transmission Such a view extends the application of the general principle of selection through fitness to the activities of the organism. After years of study and experiment with children, etc., devoted to this problem, the writer is con- vinced that this 'functional selection ' bears much the same relation to the doctrine of the special creation of ontogenic accommodations by consciousness which Professor Cope is reviving, that the Darwinian theory of natural selection bears to the special creation theory of the phylogenetic adaptations of species. The facts which Spencer called ' heightened discharge ' are capable of formulation of the principle of ' motor excess ' : ' the accommodation of an organism to a new stimulation is secured — not by the selection of this stimulation beforehand (nor of the neces- sary movements) — but by the reinstatement of it by a discharge of the energies of the organism, concentrated, as far as may be, for the excessive stimulation of the organs (muscles, etc.), most nearly fitted by former habit to get this stimulation again,' 1 in which the word ' stimulation ' stands for the condition favourable to adjustment. After several trials, with grotesquely excessive movements, the child, for example, gets the accommodation aimed at, more and more perfectly, and the accompanying excessive and useless movements fall away. This is the kind of ( selec- ting ' that consciousness does in its acquisition of new movements. And how the results of it are conserved from generation to generation, without the Lamarckian factor, has been spoken of above. Finally, a word merely of the relation of consciousness to the energies of the brain. It is clear that this doctrine 1 Mental Development,^. 179. Spencer and Bain hold that the selection is of purely chance adjustments among spontaneous movements. Tke Selective Process in Accommodation 89 of selection as applied to muscular movement does away with all necessity for holding that consciousness even directs brain energy. The need of such direction seems to me to be as artificial as Darwin's principle showed the need of special creation to be for the teleological adapta- tions of the different species. This necessity of supposed directive agency done away in this case as in that, the question of the relation of consciousness to the brain becomes a metaphysical one — just as that of teleology in nature became a metaphysical one- — and science can get along without asking it.1 And biological as well as psy- chological science should be glad that it is so. We may add in closing that of the three headings of this note only the last (third) is based on matters of per- sonal opinion ; the other two rest on Professor Cope's own presuppositions — that of intelligent selection in his sense of the term, and that of the bearing of social hered- ity (which he admits) upon Lamarckism. 1 See the remarks on this question, below, Chap. IX. § 3. CHAPTER VIII A FACTOR IN EVOLUTION: ORGANIC SELECTION1 IN several recent publications2 some considerations are developed, from different points of view, which tend to bring out a certain influence at work in organic evolution which we may venture to call a 'factor.' The object of the present paper is to gather into one sketch an outline of the view of the process of evolution which these different publications have hinged upon. The problems involved in a theory of organic evolution may be gathered up under three great heads : Ontogeny or the individual's development, Phylogeny or the evolu- tion of species, and Heredity. The general consideration, the ' factor ' which it is proposed to bring out, is operative in the first instance, in the field of Ontogeny ; I shall con- sequently speak first of the problem of Ontogeny ; then of that of Phylogeny, in so far as the topic dealt with makes it necessary ; then of that of Heredity, under the same limitation ; and finally, give some definitions and con- clusions. 1 From the American Naturalist^ June and July, 1896, article entitled 'A New Factor in Evolution.' Slightly revised as to terminology mainly, in accordance with the recommendations of the biological authorities of the writer's Dictionary of Philosophy (sub verbis}. 2 Preceding papers in this work. This essay was written to gather together the various points of view of the earlier papers, hence the frequent quotations from them. 90 Ontogenie Agencies 91 § i. Ontogenie Agencies Ontogeny. - - The series of facts which investigation in this field has to deal with are those of the individual creature's development, and two sorts of facts may be distinguished from the point of view of ths functions which an organism performs in the course of its life history. There is, in the first place, the development of his hereditary impulse, the unfolding of its heredity in the forms and functions which characterize its kind, together with the congenital variations which characterize the par- ticular individual — the variations peculiar and constitu- tional to him — and there is, in the second place, the series of functions, acts, etc., ivJiicli he learns for Jiimself in the course of his life. All of these latter, the special modifica- tions which an organism undergoes during its ontogeny, thrown together, have been called 'acquired characters,' and we may use that expression or adopt one recently suggested by Osborn,1 ' ontogenic variations ' (except that I should prefer the form 'ontogenetic variations') if the word 'variations' seems appropriate at all.2 Assuming that there are such new or modified functions, in the first instance, and such ' acquired characters ' aris- 1 Reported in Science, April 3 ; also used by him before the New York Academy of Science, April 13. There is some confusion between the two terminations, 'genie' and 'genetic.' I think the proper distinction is that which reserves the former, ' genie,' for application in cases in which the word to which it is affixed qualifies a term used actively, while the other, ' genetic,' conveys similarly a passive signification; thus agencies, causes, influences, etc., are 'ontogenic, phylogenic, etc.,' while effects, consequences, etc., are ' ontogenetic, phylogenetic, etc.' On terminology, see, however, the short paper reprinted below as Chap. XI. § i. 2 As it does not. The term modification, used above, is also given this mean- ing by Lloyd Morgan {Habit and Instinct, 1897) an<^ *s now widely adopted. 92 A Factor in Evolution ing by 'use and disuse' from these new functions, our further question is about them. And the question is this : How does an organism come to be modified during its life history ? In answer to this question we find that there are three different sorts of ontogenic agencies which should be dis- tinguished— each of which works to produce ontogenetic modifications or accommodations. These are : first, the physical agencies and influences in the environment which work upon the organism to produce modifications of its form and functions. They include all chemical agents, strains, contacts, hinderances to growth, temperature changes, etc. So far as these forces work changes in the organism, the changes may be considered largely 'fortuitous ' or accidental.1 Considering the nature of the forces which produce them, I propose to call these modifi- cations 'physico-genetic.' Spencer's theory of ontogenetic development rests largely upon the occurrence of lucky movements brought out by such accidental influences. Second, there is a class of modifications, in addition to those mentioned, which arise from the spontaneous activities of the organism itself in the carrying out of its normal life-functions. These modifications and adjust- ments are seen to a remarkable extent in plants, in uni- cellular creatures, in very young children. There seem to be a readiness and a capacity on the part of the organ- ism to 'rise to the occasion,' as it were, and make gain out of the circumstances of its life. The facts have been put in evidence (for plants) by Henslow, Pfeffer, Sachs ; (for micro-organisms) by Binet, Bunge ; (in human pathol- 1 That is, so far as any direct provision for them is found in the economy of the organism's growth. Ontogenic Agencies 93 ogy) by Bernheim, Janet ; (in children) among others by the present writer (in Mental Development, Chap. IX., with citations ; see also Orr, TJieory of Development, Chap. IV.). These changes I propose to call ' neuro- genetic,' laying emphasis on what is called by Romanes, LI. Morgan, and others the ' selective property ' of the nervous system, and of life generally. Third, there is the great and remarkable series of ac- commodations secured by conscious agency, which we may throw together as ' psycho-genetic.' The processes involved here are all classed broadly under the term 'intelligent,' e.g., imitation, gregarious habits, parental instruction, the lessons of pleasure and pain and of experience generally, reasoning from means to ends, etc. We reach, therefore, the following scheme : — Ontogenetic Modifications Ontogenic Agencies 1. Physico-genetic i. Mechanical. 2. Neuro-genetic 2. Nervous. 3. Psycho-genetic 3. Intelligent. Pleasure and pain. Imitation. Higher mental processes. (Association of Ideas, etc.) Now it is evident that there are two very distinct ques- tions which come up as soon as we admit modifications of function and of structure in ontogenetic development ; especially if these are considered with reference to the larger problem of evolution. First, there is the question as to how these modifications can become adaptive in the life of the individual creature ; 94 -A Factor in Evolution or, in other words : What is the method of the individual's growth and accommodation as shown in the well-known effects of ' use and disuse ' ? Looked at functionally, we see that the organism manages somehow to accommodate itself to conditions which are favourable, to repeat move- ments which are fortunate, and so to grow by the principle of use. This involves some sort of selection, from the actual modes of behaviour of certain modes — certain func- tions, etc. Certain other possible and actual functions and structures decay from disuse. Whatever the method of doing this may be, we may simply, at this point, claim the law of use and disuse, as applicable in ontogenetic development, and apply the phrase, ' Functional Selec- tion,'1 to the organism's behaviour in acquiring new modes or modifications of adaptive function with its influence on structure. The question of the method of functional selection is taken up below (§6, this chapter); here we simply assume what every one admits in some form, that such adjustments of function — 'accommodations' we shall henceforth call them, the processes of learning new move- ments, etc. — do occur. We then reach another question, second : What place have these accommodations in the general theory of evolution ? § 2. Effects of Individual Accommodation on Development In the first instance, we may note the results in the creature's own private life and development. 1 Now understood from the earlier pages. In the original paper, the term ' Organic Selection ' was used (see note at foot of page 96) to include the individual's functional accommodations, but later on the term was restricted as in what follows. Individual Accommodation on Development 95 i. By securing adjustments, accommodations, in special circumstances, the creature is kept alive. This is true in all the spheres of modification distinguished in the table above. The creatures which can stand the ' storm and stress ' of the physical influences of the environment, and of the changes which occur in these influences by undergoing modifications of their congenital functions or of the structures which are constitutional to them — these creatures will live ; while those which cannot will not live. In the sphere of neuro-genetic modification we find a superb series of adjustments made by lower as well as higher organisms during the course of their development (see citations in Mental Development, Chap. IX. ; the work of Davenport, Experimental Morphology, is devoted largely to this subject). And in the highest sphere, that of in- telligence (including the phenomena of consciousness of all kinds, experience of pleasure and pain, imitation, etc.), we find individual accommodations on the extended scale which culminates in the skilful performances of human volition, invention, etc. The progress of the child in all the learning processes which lead him on to be a man illustrates this higher form of personal accommodation. All these instances are associated in the higher organ- isms, and all of them unite to keep the creature alive. Passing on to consider an indirect effect of this, we find a very striking consequence. 2. By this means those congenital or phylogenetic varia- tions are kept in existence ^LvhicJi lend themselves to intelli- gent, imitative, adaptive, or mechanical modification during the lifetime of the creatures wJiicJi have them. Other con- genital variations are not thus kept in existence. So there arises a more or less widespread series of modifica- 96 A Factor in Evolution tions in each generation's development^ in which the con- genital and the acquired unite to produce a definite or determinate direction of change. Those individuals in which this union of the two factors does not occur are — apart from other possible reasons for survival - incapable of maintaining the struggle for existence, and are eliminated. The further applications of the principle lead us over into the field of our second question, that of phylogeny or evolution. § 3. Effects of Individual Accommodation on Evolution Phylogeny: A. Physical Heredity. — The question of phylogenetic descent considered apart, in so far as may be, from that of heredity, is the question as to what the factors really are which show themselves in evolutionary progress from generation to generation. The most impor- 1^ If .^\ c 71 ^ cln c, n' 3 Theory of Neo-Darwinism or Weismannism. LL', line of evolution ; i, 2, etc., successive generations by physical heredity; cm, cm', etc., congenital mean; v, v' , variations (congenital). Evolution is by natural selection of variations added to the congenital mean from generation to generation. English vf QT& plastic) appropriately designates a view which mainly concerns itself with the factors at work in the determination or direction of the movement of evolution. The relation of this theory to other current general views is indicated here and there in the preceding pages. Many of the papers here reprinted were written in the first instance to show that this theory is free from objec- tions urged to Neo-Lamarckism and Neo-Darwinism ; and it has been pointed out in what way orthoplasy finds itself ' orientated ' with respect to the less general truths on i88 Orthoplasy which all the theories must ultimately repose. We may accordingly display, by the three cuts given herewith, the Theory of Lamarckism or Neo-Lamarckism. LL', line of evolution; i, 2, etc., successive generations by physical heredity; c, c' , etc., congenital endowment; a, a', etc., modifications (acquired). The modification of one generation is added to the endowment of the next by the principle of use-inheritance. T 1 >' 3" 4" I ~-~~i i i