The Project Gutenberg EBook of The Science and Philosophy of the Organism, by Hans Driesch This eBook is for the use of anyone anywhere at no cost and with almost no restrictions whatsoever. You may copy it, give it away or re-use it under the terms of the Project Gutenberg License included with this eBook or online at www.gutenberg.org Title: The Science and Philosophy of the Organism The Gifford Lectures Delivered Before the University of Aberdeen in the Year 1907 Author: Hans Driesch Release Date: December 8, 2013 [EBook #44388] Language: English Character set encoding: UTF-8 *** START OF THIS PROJECT GUTENBERG EBOOK THE SCIENCE AND PHILOSOPHY *** Produced by Marilynda Fraser-Cunliffe, Thiers Halliwell and the Online Distributed Proofreading Team at http://www.pgdp.net Transcriber’s notes: In this transcription, page numbers are shown in the right margin, and page footnotes (renumbered in consecutive order) are grouped together at the end of the book. Hyperlinks to footnotes and page references are indicated by black dotted underlines plus aqua highlighting when the mouse pointer hovers over them. The footnotes are themselves hyperlinked back to the originating marker to facilitate easy return to the text. A red dashed underline as shown here indicates the presence of a transcriber’s comment; scrolling the mouse pointer over such text will reveal the comment. The rare spelling typos noted in the original text have been corrected silently (e.g. invividual-->individual, hyberbola-- >hyperbola) but inconsistent use of the ligature æ/ae (e.g. palæontology/palaeontology), inconsistent use of alternative spellings (e.g. learned/learnt), and occasional inconsistencies of hyphenation have been left as in the original. Minor punctuation typos have been corrected silently (e.g. index entries with missing commas). The abbreviation viz. appears in both roman and italic font. Formatting of entries in the Table of Contents does not accurately match that of the corresponding headings in the text, particularly the heading Pt.I-B-3 which contains an extraneous α. In Figure 12 caption, multiple ditto marks have been replaced by the relevant text for greater clarity. THE SCIENCE AND PHILOSOPHY OF THE ORGANISM AGENTS AMERICA THE MACMILLAN COMPANY 64 & 66 FIFTH AVENUE, NEW YORK AUSTRALASIA THE OXFORD UNIVERSITY PRESS, MELBOURNE CANADA THE MACMILLAN COMPANY OF CANADA, LTD. 27 RICHMOND STREET WEST, TORONTO INDIA MACMILLAN & COMPANY, LTD. MACMILLAN BUILDING, BOMBAY 309 BOW BAZAAR STREET, CALCUTTA THE SCIENCE AND PHILOSOPHY OF THE ORGANISM THE GIFFORD LECTURES DELIVERED BEFORE THE UNIVERSITY OF ABERDEEN IN THE YEAR 1907 BY HANS DRIESCH, Ph.D. HEIDELBERG LONDON ADAM AND CHARLES BLACK 1908 All rights reserved PREFACE This work is not a text-book of theoretical biology; it is a systematic presentment of those biological topics which bear upon the true philosophy of nature. The book is written in a decidedly subjective manner, and it seems to me that this is just what “Gifford Lectures” ought to be. They ought never to lose, or even try to lose, their decidedly personal character. My appointment as Gifford Lecturer, the news of which reached me in February 1906, came just at the right moment in the progress of my theoretical studies. I had always tried to improve my previous books by adding notes or altering the arrangement; I also had left a good deal of things unpublished, and thus I often hoped that I might have occasion to arrange for a new, improved, and enlarged edition of those books. This work then is the realisation of my hopes; it is, in its way, a definitive statement of all that I have to say about the Organic. The first volume of this work, containing the lectures for 1907—though the division into “lectures” has not been preserved—consists of Parts I. and II. of Section A, “The Chief Results of Analytical Biology.” It gives in Part I. a shortened, revised, and, as I hope, improved account of what was published in my Analytische Theorie der organischen Entwickelung (1894), Die Localisation morphogenetischer Vorgänge; ein Beweis Vitalistischen Geschehens (1899), and Die organischen Regulationen (1901), though for the professed biologist the two last- named books are by no means superseded by the new work. Part II. has never been published in any systematic form before, though there are many remarks on Systematics, Darwinism, etc., in my previous papers. The second volume—to be published in the autumn, after the delivery of the 1908 lectures—will begin with the third and concluding part of the scientific section, which is a very carefully revised and rearranged second edition of my book, Die “Seele” als elementarer Naturfactor (1903). The greater part of this volume, however, will be devoted to the “Philosophy of the Organism,” i.e. Section B, which, in my opinion, includes the most important parts of the work. Some apology is needed for my presuming to write in English. I was led to do so by the conviction, mistaken perhaps, that the process of translation would rob the lectures of that individual and personal character which, as I said before, seems to me so much to be desired. I wished nothing to come between me and my audience. I accordingly wrote my manuscript in English, and then submitted it to linguistic revision by such skilled aid as I was able to procure at Heidelberg. My reviser tells me that if the result of his labours leaves much to be desired, it is not to be wondered at, v vi vii but that, being neither a biologist nor a philosopher, he has done his best to make me presentable to the English reader. If he has failed in his troublesome task, I know that it is not for want of care and attention, and I desire here to record my sense of indebtedness to him. He wishes to remain anonymous, but I am permitted to say that, though resident in a foreign university, he is of Scottish name and English birth. My gratitude to my friends at Aberdeen, in particular to Professor and Mrs. J. A. Thomson, for their hospitality and great kindness towards me cannot be expressed here; they all know that they succeeded in making me feel quite at home with them. I am very much obliged to my publishers, Messrs. A. and C. Black, for their readiness to fulfil all my wishes with respect to publication. The lectures contained in this book were written in English by a German and delivered at a Scottish university. Almost all of the ideas discussed in it were first conceived during the author’s long residence in Southern Italy. Thus this book may be witness to the truth which, I hope, will be universally recognised in the near future—that all culture, moral and intellectual and aesthetic, is not limited by the bounds of nationality. HANS DRIESCH. Heidelberg, 2nd January 1908. CONTENTS OF THE FIRST VOLUME THE PROGRAMME PAGE On Lord Gifford’s Conception of “Science” 1 Natural Sciences and “Natural Theology” 3 Our Philosophical Basis 5 On Certain Characteristics of Biology as a Science 9 The Three Different Types of Knowledge about Nature 13 General Plan of these Lectures 15 General Character of the Organic Form 19 SECTION A.—THE CHIEF RESULTS OF ANALYTICAL BIOLOGY PART I.—THE INDIVIDUAL ORGANISM WITH REGARD TO FORM AND METABOLISM A. ELEMENTARY MORPHOGENESIS— Evolutio and Epigenesis in the old Sense 25 The Cell 27 The Egg: its Maturation and Fertilisation 31 The First Developmental Processes of Echinus 33 Comparative Embryology 44 The First Steps of Analytical Morphogenesis 45 The Limits of Pure Description in Science 50 B. EXPERIMENTAL AND THEORETICAL MORPHOGENESIS— 1. The Foundations of the Physiology of Development. “Evolutio” and “Epigenesis” 52 The Theory of Weismann 52 Experimental Morphology 56 The Work of Wilhelm Roux 58 The Experiments on the Egg of the Sea-urchin 59 On the Intimate Structure of the Protoplasm of the Germ 65 On some Specificities of Organisation in Certain Germs 70 General Results of the First Period of “Entwickelungsmechanik” 71 Some New Results concerning Restitutions 74 2. Analytical Theory of Morphogenesis 76 α. the distribution of morphogenic potencies 76 Prospective Value and Prospective Potency 76 The Potencies of the Blastomeres 79 The Potencies of Elementary Organs in General 80 Explicit and Implicit Potencies: Primary and Secondary Potencies 83 ix x The Morphogenetic Function of Maturation in the Light of Recent Discoveries 85 The Intimate Structure of Protoplasm: Further Remarks 88 The Neutrality of the Concept of “Potency” 89 β. the “means” of morphogenesis 89 β′. The Internal Elementary Means of Morphogenesis 90 Some Remarks on the Importance of Surface Tension in Morphogenesis 91 On Growth 93 On Cell-division 94 β″. The External Means of Morphogenesis 95 The Discoveries of Herbst 96 γ. the formative causes or stimuli 99 The Definition of Cause 99 Some Instances of Formative and Directive Stimuli 102 δ. the morphogenetic harmonies 107 ε. on restitutions 110 A few Remarks on Secondary Potencies and on Secondary Morphogenetic Regulations in General 110 The Stimuli of Restitutions 113 3. The Problem of Morphogenetic Localisation: The Theory of the Harmonious- Equipotential system—First Proof of the Autonomy of Life 118 The General Problem 118 The Morphogenetic “System” 119 The “Harmonious-equipotential System” 122 Instances of “Harmonious-equipotential Systems” 126 The Problem of the Factor E 132 No Explanation offered by “Means” or “Formative Stimuli” 132 No Explanation offered by a Chemical Theory of Morphogenesis 134 No Machine Possible Inside the Harmonious Systems 138 The Autonomy of Morphogenesis proved 142 “Entelechy” 143 Some General Remarks on Vitalism 145 The Logic of our First Proof of Vitalism 146 4. On Certain other Features of Morphogenesis Advocating its Autonomy 150 Harmonious-equipotential Systems formed by Wandering Cells 151 On Certain Combined Types of Morphogenetic Systems 153 The “Morphaesthesia” of Noll 157 Restitutions of the Second Order 158 On the “Equifinality” of Restitutions 159 Remarks on “Retro-Differentiation” 163 C. ADAPTATION— Introductory Remarks on Regulations in General 165 1. Morphological Adaptation 168 The Limits of the Concept of Adaptation 168 Adaptations to Functional Changes from Without 172 True Functional Adaptation 176 Theoretical Conclusions 179 2. Physiological Adaptation 184 Specific Adaptedness not “Adaptation” 186 Primary and Secondary Adaptations in Physiology 188 On Certain Pre-requisites of Adaptations in General 189 On Certain Groups of Primary Physiological Adaptations 190 General Remarks on Irritability 190 The Regulation of Heat Production 193 Primary Regulations in the Transport of Materials and Certain Phenomena of Osmotic Pressure 194 Chromatic Regulations in Algae 197 Metabolic Regulations 198 Immunity the only Type of a Secondary Physiological Adaptation 204 No General Positive Result from this Chapter 209 A few Remarks on the Limits of Regulability 212 D. INHERITANCE. SECOND PROOF OF THE AUTONOMY OF LIFE— The Material Continuity in Inheritance 214 xi xii On Certain Theories which Seek to Compare Inheritance to Memory 216 The Complex-Equipotential System and its Rôle in Inheritance 219 The Second Proof of Life-Autonomy. Entelechy at the Bottom of Inheritance 224 The Significance of the Material Continuity in Inheritance 227 The Experimental Facts about Inheritance 228 The Rôle of the Nucleus in Inheritance 233 Variation and Mutation 237 Conclusions from the First Main Part of these Lectures 240 PART II.—SYSTEMATICS AND HISTORY A. THE PRINCIPLES OF SYSTEMATICS— Rational Systematics 243 Biological Systematics 246 B. THE THEORY OF DESCENT— 1. Generalities 250 The Covert Presumption of all Theories of Descent 253 The Small Value of Pure Phylogeny 255 History and Systematics 257 2. The Principles of Darwinism 260 Natural Selection 261 Fluctuating Variation the Alleged Cause of Organic Diversity 264 Darwinism Fails all along the Line 269 3. The Principles of Lamarckism 271 Adaptation as the Starting-Point 272 The Active Storing of Contingent Variations as a Hypothetic Principle 273 Criticism of the “Inheritance of Acquired Characters” assumed by Lamarckism 275 Other Principles Wanted 281 Criticism of the Hypothesis of Storing and Handing Down Contingent Variations 282 4. The Real Results and the Unsolved Problems of Transformism 290 5. The Logical Value of the Organic Form according to the different Transformistic Theories 293 The Organic Form and Entelechy 294 C. THE LOGIC OF HISTORY 297 1. The Possible Aspects of History 299 2. Phylogenetic Possibilities 304 3. The History of Mankind 306 Cumulations in Human History 308 Human History not an “Evolution” 311 The Problem of the “Single” as such 315 Conclusions about Systematics and History in General 322 THE PROGRAMME On Lord Gifford’s Conception of “Science” This is the first time that a biologist has occupied this place; the first time that a biologist is to try to carry out the intentions of the noble and high-minded man to whom this lectureship owes its foundation. On such an occasion it seems to be not undesirable to inquire what Lord Gifford’s own opinions about natural science may have been, what place in the whole scheme of human knowledge he may have attributed to those branches of it which have become almost the centre of men’s intellectual interest. And, indeed, on studying Lord Gifford’s bequest with the object of finding in it some reference to the natural sciences, one easily notes that he has assigned to them a very high place compared with the other sciences, at least in one respect: xiii 1 with regard to their methods. There is a highly interesting passage in his will which leaves no doubt about our question. After having formally declared the foundation of this lectureship “for Promoting, Advancing, Teaching and Diffusing the study of Natural Theology in the widest sense of that term,” and after having arranged about the special features of the lectures, he continues: “I wish the lecturers to treat their subject as a strictly natural science, the greatest of all possible sciences, indeed, in one sense, the only science, that of Infinite Being. . . . I wish it considered just as astronomy or chemistry is.” Of course, it is not possible to understand these words of Lord Gifford’s will in a quite literal sense. If, provisionally, we call “natural theology” the ultimate conclusions which may be drawn from a study of nature in connection with all other results of human sciences, there cannot be any doubt that these conclusions will be of a rather different character from the results obtained in, say, the special field of scientific chemistry. But, nevertheless, there are, I think, two points of contact between the wider and the narrower field of knowledge, and both of them relate to method. Lord Gifford’s own phrase, “Infinite Being,” shows us one of these meeting-points. In opposition to history of any form, natural sciences aim at discovering such truths as are independent of special time and of special space, such truths as are “ideas” in the sense of Plato; and such eternal results, indeed, always stand in close relation to the ultimate results of human knowledge in general. But besides that there is still another feature which may be common both to “natural theology” and to the special natural sciences, and which is most fully developed in the latter: freedom from prepossessions. This, at least, is an ideal of all natural sciences; I may say it is the ideal of them. That it was this feature which Lord Gifford had in view in his comparison becomes clear when we read in his will that the lectures on natural theology are to be delivered “without reference to or reliance upon any supposed special exceptional or so-called miraculous revelation.” So we might say that both in their logical and their moral methods, natural sciences are to be the prototype of “Natural Theology” in Lord Gifford’s sense. Natural Sciences and “Natural Theology” But now let us study in a more systematic manner the possible relations of the natural sciences to natural theology as a science. How is it possible for a natural scientist to contribute to the science of the highest and ultimate subject of human knowledge? Almost all natural sciences have a sort of naïveté in their own spheres; they all stand on the ground of what has been called a naïve realism, as long as they are, so to say, at home. That in no way prejudices their own progress, but it seems to stand in the way of establishing contact with any higher form of human knowledge than themselves. One may be a first-rate organic chemist even when looking upon the atoms as small billiard balls, and one may make brilliant discoveries about the behaviour of animals even when regarding them in the most anthropomorphic manner—granted that one is a good observer; but it can hardly be admitted that our chemist would do much to advance the theory of matter, or our biologist to solve the problem of the relations between body and mind. It is only by the aid of philosophy, or I would rather say by keeping in constant touch with it, that natural sciences are able to acquire any significance for what might be called the science of nature in the most simple form. Unhappily the term “natural philosophy” is restricted in English to theoretical physics. This is not without a high degree of justification, for theoretical physics has indeed lost its naïveté and become a philosophy of nature; but it nevertheless is very unfortunate that this use of the term “natural philosophy” is established in this country, as we now have no proper general term descriptive of a natural science that is in permanent relation to philosophy, a natural science which does not use a single concept without justifying it epistemologically, i.e. what in German, for instance, would simply be called “Naturphilosophie.” Let us call it philosophy of nature; then we may say that only by becoming a true philosophy of nature are natural sciences of all sorts able to contribute to the highest questions which man’s spirit of inquiry can suggest. These highest questions themselves are the outcome of the combination of the highest results of all branches of philosophy, just as our philosophy of nature originated in the discussion of the results of all the separate natural sciences. Are those highest questions not only to be asked, are they to be also solved? To be solved in a way which does not exceed the limits of philosophy as the domain of actual understanding? The beginning of a long series of studies is not the right place to decide this important question; and so, for the present certainly, “natural theology” must remain a problem. In other words: it must remain an open question at the beginning of our studies, whether after all there can be any final general answer, free from contradictions, applicable to the totality of questions asked by all the branches of philosophy. But let us not be disturbed by this problematic entrance to our studies. Let us follow biology on its own path; let us study its transition from a “naïve” science to a real branch of the philosophy of nature. In this way we perhaps shall be able to understand what its part may be in solving what can be solved. That is to be our subject. Our Philosophical Basis 2 3 4 5 We call nature what is given to us in space. Of course we are not obliged in these lectures to discuss the psychological and epistemological problems of space with its three dimensions, nor are we obliged to develop a general theory of reality and its different aspects. A few epistemological points will be considered later at proper times, and always in connection with results of theoretical biology. At present it must suffice to say that our general philosophical point of view will be idealistic, in the critical meaning of the word. The universe, and within the universe nature, in the sense just defined, is my phenomenon. That is what I know. I know nothing more, either positively or negatively; that is to say, I do not know that the world is only my phenomenon, but, on the other hand, I know nothing about its “absolute reality.” And more, I am not even able to describe in intelligible words what “absolute reality” might mean. I am fully entitled to state: the universe is as truly as I am—though in a somewhat different sense of “being”—and I am as truly as the universe is; but I am not entitled to state anything beyond these two corresponding phrases. You know that, in the history of European philosophy at least, Bishop Berkeley was the first clearly to outline the field of idealism. But my phenomenon—the world, especially nature—consists of elements of two different kinds: some of them are merely passive, some of them contain a peculiar sort of activity in themselves. The first are generally called sensations, but perhaps would be better called elements or presentations; the others are forms of construction, and, indeed, there is an active element embraced in them in this sense, that they allow, by their free combination, the discovery of principles which are not to be denied, which must be affirmed, whenever their meaning is understood. You know that I am speaking here of what are generally called categories and synthetic judgments a priori, and that it was Kant who, on the foundations laid by Locke, Hume, and Leibnitz, first gave the outlines of what may be called the real system of critical philosophy. Indeed, our method will be to a great extent Kantian, though with certain exceptions; it is to be strictly idealistic, and will not in the Kantian way operate with things in themselves; and it regards the so-called “synthetic judgment a priori” and the problem of the relation between categorical principles and experience in a somewhat different manner. We think it best to define the much disputed concept “a priori” as “independent of the amount of experience”; that is to say, all categories and categorical principles are brought to my consciousness by that fundamental event which is called experience, and therefore are not independent of it, but they are not inferences from experience, as are so-called empirical laws. We almost might say that we only have to be reminded of those principles by experience, and, indeed, we should not, I think, go very far wrong in saying that the Socratic doctrine, that all knowledge is recollection, holds good as far as categories and categorical principles are in question. But enough at present about our general philosophy. As to the philosophy of nature, there can be no doubt that, on the basis of principles like those we have shortly sketched, its ultimate aim must be to co-ordinate everything in nature with terms and principles of the categorical style. The philosophy of nature thus becomes a system; a system of which the general type is afforded by the innate constructive power of the Ego. In this sense the Kantian dictum remains true, that the Ego prescribes its own laws to nature, though, of course, “nature,” that is, what is given in space, must be such as to permit that sort of “prescription.” One often hears that all sciences, including the science of sciences, philosophy, have to find out what is true. What, then, may be called “true” by an idealistic philosopher, for whom the old realistic formula of the conformity between knowledge and the object cannot have any meaning? Besides its ordinary application to simple facts or to simple judgments, where the word truth only means absence of illusion or no false statement, truth can be claimed for a philosophical doctrine or for a system of such doctrines only in the sense that there are no contradictions amongst the parts of the doctrine or of the system themselves, and that there are no features in them which impel our categorical Ego to further analysis. Those of you who attended Professor Ward’s lectures on “Naturalism and Agnosticism,” or who have read his excellent book on that subject, will know what the aims of a theory of matter are. You will also be aware that, at present, there does not exist any theory of matter which can claim to be “true”; there are contradictions in every theory of matter, and, moreover, there are always some points where we are obliged to ask for further information and receive no answer. Experience here has not yet aroused all the categorical functions which are needed in order to form one unity out of what seem to be incompatibilities at the present day. Why is that? Maybe because experience is not yet complete in this field, but maybe also because the whole subject is so complicated that it takes much time to attach categorical functions to what is experienced. But it is not our object here to deal either with epistemology proper or with ontology: a full analysis of biological facts is our problem. Why, then, all these introductions? why all these philosophical sketches in fields of knowledge which have quite another relation to philosophy than biology has? Biology, I hear some one say, is simply and solely an empirical science; in some sense it is nothing but applied physics and chemistry, perhaps applied mechanics. There are no fundamental principles in biology which could bring it in any close contact with philosophy. Even the one and only principle which might seem to be an innate principle of our experience about life, the principle of evolution, is only a combination of more simple factors of the physical and chemical type. It will be my essential endeavour to convince you, in the course of these lectures, that such an aspect of the science of biology is wrong; that biology is an elemental natural science in the true sense of the word. But if biology is an elemental science, then, and only then, it stands in close relations to epistemology and ontology—in the same relations to them, indeed, as every natural science does which deals with true elements of nature, and which is 6 7 8 9 willing to abandon naïve realism and contribute its share to the whole of human knowledge. And, therefore, a philosophical sketch is not out of place at the beginning of lectures on the Philosophy of the Organism. We may be forced, we, indeed, shall be forced, to remain for some time on the ground of realistic empiricism, for biology has to deal with very complicated experiences; but there will be a moment in our progress when we shall enter the realm of the elemental ontological concepts, and in that very moment our study of life will have become a part of real philosophy. It was not without good reasons, therefore, that I shortly sketched, as a sort of introduction to my lectures, the general point of view which we shall take with regard to philosophical questions, and to questions of the philosophy of nature in particular. On Certain Characteristics of Biology as a Science Biology is the science of life. Practically, all of you know what a living being is, and therefore it is not necessary to formulate a definition of life, which, at the beginning of our studies, would be either provisional and incomplete, or else dogmatic. In some respects, indeed, a definition should rather be the end of a science than its opening. We shall study the phenomena of living organisms analytically, by the aid of experiment; our principal object will be to find out laws in these phenomena; such laws will then be further analysed, and precisely at that point we shall leave the realm of natural science proper. Our science is the highest of all natural sciences, for it embraces as its final object the actions of man, at least in so far as actions also are phenomena observable on living bodies. But biology is also the most difficult of all natural sciences, not only from the complexity of the phenomena, which it studies, but in particular for another reason which is seldom properly emphasised, and therefore will well repay us for a few words devoted to it. Except so far as the “elements” of chemistry come into account, the experimenter in the inorganic fields of nature is not hampered by the specificity of composite objects: he makes all the combinations he wants. He is always able to have at his disposal red rays of a desired wave length when and where he wants, or to have, at a given time and place, the precise amount of any organic compound which he wishes to examine. And he forces electricity and electromagnetism to obey his will, at least with regard to space, time, and intensity of their appearance. The biologist is not able to “make” life, as the physicist has made red rays or electromagnetism, or as the chemist has made a certain compound of carbon. The biologist is almost always in that strange plight in which the physicist would be if he always had to go to volcanoes in order to study the conductivity of heat, or if he had to wait for thunderstorms in order to study electricity. The biologist is dependent on the specificity of living objects as they occur in nature. A few instances may show you what great inconveniences may hence arise to impede practical biological research. We later on shall have to deal with experiments on very young embryos: parts of the germ will have to be destroyed in order to study what will happen with the rest. Now almost all germs are surrounded by a membrane; this membrane has to be detached before any operation is possible. But what are we to do if it is not possible to remove the membrane without killing the embryo? Or what if, as for instance in many marine animals, the membrane may be removed but the germs are killed by contact with sea-water? In both cases no experiments at all will be possible on a sort of germ which otherwise, for some special circumstances of its organisation, might have given results of importance. These results become impossible for only a practical, for a very secondary reason; but enough: they are impossible, and they might have thrown light on problems which now must remain problems. Quite the same thing may occur in experiments on physiology proper or functional physiology: one kind of animals survives the operation, the other kind does not, and therefore, for merely extrinsic reasons, the investigations have to be restricted to the first, though the second might have given more important results. And thus the biological experimenter always finds himself in a sort of dependence on his subjects, which can hardly be called pleasant. To a great extent the comparatively slow advance of biological sciences is due to this very fact: the unalterable specific nature of biological material. But there is still another feature of biology dependent on the same fact. If a science is tied down to specific objects in every path it takes, it first, of course, has to know all about those objects, and that requires nothing else but plain description. We now understand why pure description, in the most simple sense of the word, takes up such an enormous part of every text-book of biological science. It is not only morphology, the science of form, that is most actively concerned with description; physiology also, in its present state, is pure description of what the functions of the different parts of the body of animals and plants actually are, at least for about nine-tenths of its range. It seems to me important to press this point very emphatically, since we often hear that physiology is from the very beginning a much higher sort of knowledge than morphology, inasmuch as it is rational. That is not at all true of the beginning of physiology: what the functions of the liver or of the root are has simply to be described just as the organisation of the brain or of the leaf, and it makes no difference logically that one species of description has to use the experimental method, while the other has not. The experiment which only discovers what happens here or what happens there, possesses no kind of logical superiority over pure description at all. But there will be another occasion in our lectures to deal more fully with the logic of experiment and with the differences of descriptive knowledge and real rational science. The three Different Types of Knowledge about Nature 10 11 12 13 Natural sciences cannot originate before the given phenomena of nature have been investigated in at least a superficial and provisional manner, by and for the practical needs of man. But as soon as true science begins in any limited field, dealing, let us say, with animals or with minerals, or with the properties of bodies, it at once finds itself confronted by two very different kinds of problems, both of them—like all “problems”—created in the last resort by the logical organisation of the human mind, or, to speak still more correctly, of the Ego. In any branch of knowledge which practical necessities have separated from others, and which science now tries to study methodically, there occur general sequences in phenomena, general orders of events. This uniformity is revealed only gradually, but as soon as it has shown itself, even in the least degree, the investigator seizes upon it. He now devotes himself chiefly, or even exclusively, to the generalities in the sequences of all changes. He is convinced that there must be a sort of most general and at the same time of most universal connection about all occurrences. This most universal connection has to be found out; at least it will be the ideal that always will accompany the inquiring mind during its researches. The “law of nature” is the ideal I am speaking about, an ideal which is nothing less than one of the postulates of the possibility of science at all. Using for our purposes a word which has been already introduced into terminology by the philosopher Windelband, though in a somewhat different sense, we shall call that part of every branch of natural sciences which regards the establishment of a law of nature as its ideal, “nomothetic,” i.e. “law-giving.” But while every natural science has its nomothetic side, it also has another half of a very different kind. This second half of every natural science does not care for the same general, the same universal, which is shown to us in every event in a different and specified kind: it is diversity, it is specification, that constitutes the subject of its interest. Its aim is to find a sufficient reason for the types of diversities, for the types of specifications. So in chemistry there has been found a systematic order in the long series of the compounds and of the elements; crystallography also has its different systems of crystals, and so on. We have already employed the word by which we shall designate this second half of every natural science: it is the “systematic” side of science. Nomothetic work on the one side and systematics on the other do, in fact, appear in every natural science, and besides them there are no other main parts. But “science” as a whole stands apart from another aspect of reality which is called “history.” History deals with particulars, with particular events at such and such a place, whilst science always abstracts from the particular, even in its systematic half. General Plan of these Lectures Turning now to a sort of short outline of what is to be discussed in the whole of our future lectures, this summer and next, it seems clear, without further analysis, that biology as a science has its nomothetic and its systematic part also; respiration and assimilation, for instance, have proved to be types of natural laws among living phenomena, and that there is a “system” of animals and plants is too commonly known to require further explanation here. Therefore we might study first biological laws, and after that biological systematics, and in the third place perhaps biological history. But that would hardly correspond to the philosophical aims of our lectures: our chief object is not biology as a regular science, as treated in text-books and in ordinary university lectures; our chief object is the Philosophy of the Organism, as aided and supported by scientific biology. Therefore a general acquaintance with biology must be assumed in these lectures, and the biological materials must be arranged according to their bearing on further, that is on philosophical, analysis. That will be done, not, of course, to the extent of my regarding every one of my audience as a competent biologist; on the contrary, I shall explain most fully all points of biology proper, and even of the most simple and descriptive kind of biology, which serve as bases for philosophical analysis. But I shall do so only if they indeed do serve as such bases. All our biology will be not for its own sake, but for the sake of philosophy. Whilst regarding the whole of the biological material with such aims, it seems to me best to arrange the properly scientific material which is to be the basis of my discussions, not along the lines which biology as an independent science would select, but to start from the three different kinds of fundamental phenomena which living bodies offer to investigation, and to attach all systematics exclusively to one of them. For there will not be very much for philosophy to learn from biological systematics at present. Life is unknown to us except in association with bodies: we only know living bodies and call them organisms. It is the final object of all biology to tell us what it ultimately means to say that a body is “living,” and in what sorts of relation body and life stand one to the other. But at present it is enough to understand the terms “body” and “living” in the ordinary and popular sense. Regarding living bodies in this unpretentious manner, and recollecting what the principal characters are of all bodies we know as living ones, we easily find that there are three features which are never wanting wherever life in bodies occurs. All living bodies are specific as to form—they “have” a specific form, as we are accustomed to say. All living bodies also exhibit metabolism; that is to say, they stand in a relation of interchange of materials with the surrounding medium, they take in and give out materials, but their form can remain unchanged during these processes. And, in the last place, we can say that all living bodies move; though this faculty is more commonly known among animals only, even elementary science teaches the student that it also belongs to plants. 14 1 15 16 2 Therefore we may ask for “laws of nature” in biology about form, about metabolism, and about movements. In fact, it is according to this scheme that we shall arrange the materials of the biological part of our lectures, though, as we cannot regard the three divisions as equally important in their bearing on our ultimate purposes, we shall not treat them quite on equal terms. It will appear that, at least in the present state of science, the problems of organic form and of organic movement have come into much closer relation to philosophical analysis than have most of the empirical data on metabolism. It is form particularly which can be said to occupy the very centre of biological interest; at least it furnishes the foundation of all biology. Therefore we shall begin our scientific studies with a full and thorough analysis of form. The science of living forms, later on, will afford us a key to study metabolism proper with the greatest advantage for our philosophical aims, and therefore the physiology of what is usually called the vegetative functions will be to us a sort of appendix to our chapters on form; only the theory of a problematic “living substance” and of assimilation in the most general meaning of the word will be reserved for the philosophical part; for very good reasons, as I hope to show. But our chapters on the living forms will have yet another appendix besides the survey of the physiology of metabolism. Biological systematics almost wholly rests on form, on “morphology”; and what hitherto has been done on the metabolical side of their problems, consists of a few fragments, which are far from being an equivalent to the morphological system; though, of course it must be granted that, logically, systematics, in our general meaning of the word, as the sum of problems about the typically different and the specific, may be studied on the basis of each one of the principal characteristics of living bodies, not only on that of their forms. Therefore, systematics is to be the second appendix to the chief part of our studies in morphology, and systematics, in its turn, will later on lead us to a short sketch of the historical side of biology, to the theory of evolution in its different forms, and to the logic of history in general. So far will our programme be carried out during this summer. Next year the theory of movements will conclude our merely scientific analysis, and the remaining part of the course next summer will be devoted to the philosophy of living nature. I hope that nobody will be able to accuse our philosophy of resting on unsound foundations. But those of you, on the other hand, who would be apt to regard our scientific chapters as a little too long compared with their philosophical results, may be asked to consider that a small clock-tower of a village church is generally less pretentious but more durable than the campanile of San Marco has been. Indeed, these lectures will afford more “facts” to my hearers, than Gifford Lectures probably have done, as a rule. But how could that be otherwise on the part of a naturalist? Scientific facts are the material that the philosophy of nature has to work with, but these facts, unfortunately, are not as commonly known as historical facts, for instance, generally are; and they must be known, in order that a philosophy of the organism may be of any value at all, that it may be more than a mere entertainment. Goethe once said, that even in so-called facts there is more “theory” than is usually granted; he apparently was thinking of what might be called the ultimate or the typical facts in science. It is with such typical or ultimate facts, of course, that we must become acquainted if our future philosophy is to be of profit to us. Certainly, there would be nothing to prevent us from arranging our materials in a manner exactly the reverse of that which we shall adopt; we could begin with a general principle about the organic, and could try to deduce all its special features from that principle, and such a way perhaps would seem to be the more fascinating method of argument. But though logical it would not be psychological, and therefore would be rather unnatural. And thus our most general principle about the organic will not come on the scene before the eighteenth of these twenty lectures, although it is not a mere inference or deduction from the former lectures: it will be a culmination of the whole, and we shall appreciate its value the better the more we know what that whole really is. General Character of the Organic Form Our programme of this year, it was said, is to be devoted wholly to organic forms, though one of its appendixes, dealing with some characteristics of the physiology of metabolism, will lead us on to a few other phenomena. What then are the essentials of a living form, as commonly understood even without a special study of biology? Living bodies are not simple geometrical forms, not, like crystals, merely a typical arrangement of surfaces in space, to be reduced theoretically, perhaps, to an arrangement of molecules. Living bodies are typically combined forms; that is to say, they consist of simpler parts of different characters, which have a special arrangement with regard to one another; these parts have a typical form of their own and may again be combinations of more simple different parts. But besides that, living bodies have not always the same typically combined form during the whole of their life: they become more complicated as they grow older; they all begin from one starting point, which has little form at all, viz., the egg. So the living form may be called a “genetic form,” or a form considered as a process, and therefore morphogenesis is the proper and adequate term for the science which deals with the laws of organic forms in general; or, if you prefer not to use the same word both for a science and for the subjects of that science, the physiology of morphogenesis. Now there are different branches of the physiology of morphogenesis or physiology of form. We may study, and indeed we at first shall study, what are the laws of the morphogenetic processes leading from the egg to the adult: that may be properly called physiology of development. But living forms are not only able to originate in one unchangeable way: they may restore themselves, if disturbed, and thus we get the physiology of restoration or restitution as a second branch of the science of morphogenesis. We shall draw very important data, some of the foundations indeed of our philosophical 17 18 19 20 discussions, from the study of such restitutions. Besides that, it is to them that our survey of the problems of the physiology of metabolism is to be appended. Living forms not only originate from the egg and are able to restore themselves, they also may give origin to other forms, guaranteeing in this way the continuity of life. The physiology of heredity therefore appears as the counterpart to those branches of the physiology of form which deal with individual form and its restitutions. And our discussion on heredity may be followed by our second appendix to this chief section on form, an appendix regarding the outlines of systematics, evolution and history. Theoretical considerations on biology generally start, or at least, used to start, from the evolution theory, discussing all other problems of the physiology of form by the way only, as things of secondary importance. You see from our programme, that we shall go just the opposite way: evolution will come last of all, and will be treated shortly; but the morphogenesis of the individual will be treated very fully, and very carefully indeed. Why then this deviation from what is the common practice? Because we do not know very much about evolution at all, because in this field we are just at the very beginning of what deserves the name of exact knowledge. But concerning individual morphogenesis we really know, even at present, if not very much, at least something, and that we know in a fairly exact form, aided by the results of experiments. And it will not be without its reward, if we restrict our aims in such a manner, if we prefer to deal more fully with a series of problems, which may seem at the first glance to be of less interest than others. After a few lectures we shall find already that we may decide one very important question about life merely by an analysis of individual form production, and without any regard to problematic and doubtful parts of biology: that we may decide the question, whether “life” is only a combination of chemical and physical events, or whether it has its elemental laws, laws of its own. But to prepare the road that is to lead to such results we first have to restrict our aims once more, and therefore the next lecture of this course, which eventually is to touch almost every concept of philosophy proper, will begin with the pure description of the individual development of the common sea-urchin. SECTION A THE CHIEF RESULTS OF ANALYTICAL BIOLOGY PART I THE INDIVIDUAL ORGANISM WITH REGARD TO FORM AND METABOLISM A. ELEMENTARY MORPHOGENESIS Evolutio and Epigenesis in the old Sense The organism is a specific body, built up by a typical combination of specific and different parts. It is implied in the words of this definition, that the organism is different, not only from crystals, as was mentioned in the last lecture, but also from all combinations of crystals, such as those called dendrites and others, which consist of a typical arrangement of identical units, the nature of their combination depending on the forces of every single one of their parts. For this reason dendrites, in spite of the typical features in their combination, must be called aggregates; but the organism is not an aggregate even from the most superficial point of view. We have said before, what must have been familiar to you already, that the organism is not always the same in its individual life, that it has its development, leading from simpler to more complicated forms of combination of parts; there is a “production of visible manifoldness” carried out during development, to describe the chief character of that process in the words of Wilhelm Roux. We leave it an open question in our present merely descriptive analysis, whether there was already a “manifoldness,” in an invisible state, before development, or whether the phrase “production of manifoldness” is to be understood in an absolute sense. It has not always been granted in the history of biology, and of embryology especially, that production of visible manifoldness is the chief feature of what is called an organism’s embryology or ontogeny: the eighteenth century is full of determined scientific battles over the question. One school, with Albert von Haller and Bonnet as its leading men, maintained the view that there was no production of different parts at all in development, this process being a mere 21 22 25 26 “evolutio,” that is, a growth of parts already existing from the beginning, yes, from the very beginning of life; whilst the other school, with C. F. Wolff and Blumenbach at its head, supported the opposite doctrine of so-called “epigenesis,” which has been proved to be the right one. To some extent these differences of opinion...