I The Project Gutenberg EBook of Parallel Paths, by Thomas William Rolleston 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/license Title: Parallel Paths A Study in Biology, Ethics, and Art Author: Thomas William Rolleston Release Date: June 14, 2014 [EBook #45971] Language: English Character set encoding: UTF-8 *** START OF THIS PROJECT GUTENBERG EBOOK PARALLEL PATHS *** Produced by Turgut Dincer, Greg Bergquist and the Online Distributed Proofreading Team at http://www.pgdp.net (This file was produced from images generously made available by The Internet Archive/American Libraries.) PARALLEL PATHS All Rights Reserved PARALLEL PATHS A STUDY IN BIOLOGY, ETHICS, AND ART BY T. W. ROLLESTON “Il faudrait, en un mot, suivre la grande route si profondément creusée ... mais il serait nécessaire aussi de tracer en l’air un chemin parallele, une autre route, d’atteindre les en deça et les après, de faire, en un mot, un naturalisme spiritualiste; ce serait autrement fier, autrement complet, autrement fort.” J. K. Huysmans. LONDON DUCKWORTH & CO. 3, HENRIETTA STREET, COVENT GARDEN 1908 PREFACE N a recent work by an eminent man of science, Dr. J. Reinke, Professor of Botany at the University of Kiel, there occurs a passage which I cannot do better than place in the forefront of this book as an indication of its aim. “Physiology,” writes Professor Reinke, “has become the study of the movements which, taken together, make up life. There is no manner of doubt that nourishment, metabolism,1 reproduction, development, and sensation rest on processes of movement which depend on material systems of peculiar molecular conformation. For the bodies of plants and of animals are [Pg i] [Pg v] material systems whose conformation is of a most intricate character. “So far as physiology has at present advanced in the analysis of these phenomena of movement, their problems have fallen naturally into two groups. The first of these groups of phenomena is comparatively transparent, and stands in agreement with the general processes of the material world; it can be investigated by observation and experiment. We may, therefore, hope to decipher it completely, and to reduce it, in the end, to chemico-physical processes. Of this kind are the phenomena of nutrition, taking that word in its widest sense. But behind these processes there stand the facts of development and of reproduction, and here, in all investigations, and in spite of every attempt to demonstrate a basis of physical energy, research finds itself confronted by an X, a factor which mocks every effort to explain it by physics or chemistry. And this X which lurks in all the phenomena of development takes a part in the nutritive processes also; so essential a factor does it appear in all the processes of life that chemical and physical forces alone would not suffice to keep alive even the most rudimentary of organisms, not to mention creating such an organism out of non-living chemical constituents.”2 If this X force exists and can be established, it will give us the clue, I believe, to much more than the operations of physical nature. The following pages are an attempt to establish it, to define its character, and to indicate the lines on which this unknown factor in evolution seems to bring into a rational unity the phenomena of the physical world and the moral and æsthetic faculties of man. The time appears to have come for such an attempt. The fermentation of mind produced by Darwin’s massive and victorious promulgation of the evolution theory is beginning to subside; it is now possible in some measure to take stock of what has been destroyed, of what has been left intact, by the immense tidal wave of new thought which then swept over the world. Some conceptions which were thought to have been submerged for ever are reappearing in more or less altered shapes, and science is called on to reconstruct a universe less one- sided, less aridly simple, than that which Darwinism, as at first understood, appeared to have left us. The result, so far as it is successful, will be the establishment of a spiritual view of the universe on a natural basis. It is an attempt which is at present occupying many minds, and which will doubtless have to occupy many more before complete success is attained. I propose, in the following pages, to take the reader over the most material and significant part of the ground by which I have myself travelled towards certain conclusions. Much of this ground lies in the region of biological science. No doubt to readers acquainted with that science I shall often seem to delay too long in well-trodden and familiar paths. But I have had to consider the fact that English education is still very much specialized. It is either literary or it is scientific. In the great majority of cases it is literary. And though scientific problems and theories are understood by every educated man and woman to be of deep importance and interest, and though questions like those discussed in the present work are questions on which all such persons are well entitled, and many feel themselves bound, to have an opinion, very few, comparatively, have even the elementary knowledge of science and its terminology necessary to enable them to take up the discussion at an advanced point. When it is announced from time to time that some chemist has again succeeded in forming an organic compound out of inorganic chemical constituents in his laboratory,[3] how many readers are there out of the small circle of trained chemists who would not be far more impressed if they heard that he had made a diamond? It is for these persons—the layman and the lay-woman in point of science—that I mainly write, and my own training having been philosophical and literary rather than scientific I think I understand most of their difficulties. I have, therefore, tried to ‘begin at the beginning’; and I hope that this book, besides whatever value its conclusions may have, will prove useful to some readers by putting them in a position to appreciate the extraordinarily interesting and fruitful discoveries of biology in recent years. “The lotus of physics,” as Schopenhauer says, “is rooted in the soil of metaphysics,” and if these studies pretended to offer a complete explanation of the riddle of existence, the metaphysical basis for the speculations contained in them would have to be elaborated at considerable length. But, after all, the conclusions reached would only be those which most people are willing to accept as a necessary assumption, if all thought on the constitution of the universe is not to be a pure futility. Suffice it to say Man is here regarded as an organic part of Nature, and his consciousness as Nature’s way of mirroring herself to herself. Since, like other natural things, the soul is not a complete and unalterable entity, but is part of the eternal Becoming, it never can be claimed that its reflection of the world is absolutely pure and complete, yet some reality, some significance this reflection must surely have. The fact that man is not something different from the world, observing it from outside, but is vitally related to it, would alone entitle us to believe that, however much his observations may need to be purified and corrected, and however false may be the argumentative deductions sometimes drawn from them, he is still capable of a real and fruitful apprehension of the phenomena by which he is surrounded, and of their relations to each other and to himself. All sincere thought must therefore tend to brighten a little the mirror of the human soul. If this book should do so in any degree, were it merely by provoking other minds to more successful labours, the writer will thankfully say, like Apollo’s temple-sweeper in the play of Euripides, Fair is the service of Light. T. W. ROLLESTON. Glenealy, Co. Wicklow. I have to thank The Macmillan Co. for permission to reproduce two illustrations (Figs. 1 and 2) from Wilson’s The Cell in Development and Inheritance, and Mr. Edward Arnold for a similar favour in regard to Fig. 3 from Weismann’s The Evolution Theory. [Pg vi] [Pg vii] [Pg viii] [Pg ix] [Pg x] CONTENTS PART I. BIOLOGY CHAPTER I The Argument from Design PAGE Paley and the Watch 1 The Analogy Inapplicable 4 Paley’s Conception of Design 8 The Evolutionary Conception 11 Conquest of Nature by the Evolution Theory 16 The Philosophic Basis of Nature-study 17 CHAPTER II The Wheel of Life Continuity of Animal, Vegetable, and Mineral Life 21 Characters of Organic Life 23 Living Matter: Its Functions 24 Its Substance 27 Its Structure 28 CHAPTER III De Minimis Growth and Development 32 Development a Cell-problem 33 The Mechanical Conception of Life 34 The Cell and its Structure 34 Cell-division and Heredity 40 Reproductive Cells and Body-cells 45 The Origin of Conjugation 46 The Mechanism of Conjugation 51 Significance of Elementary Vital Processes 59 Adaptability, a Fundamental Character of Life 63 CHAPTER IV The Mechanical Theory of Evolution: the Darwin-Lamarck Explanation The Fixity of Species, how Maintained 66 The Mutability of Species 67 Lamarck’s Explanation of the Origin of Species 68 Natural Selection of Innate Variations 72 Difficulties of Lamarckism 77 Need of a deeper Explanation 89 CHAPTER V The Mechanical Theory of Evolution: the Darwin-Weismann Explanation Lamarck, or ‘Metaphysics’? 91 Weismann’s Escape 93 The Struggle among the Determinants 95 [Pg xi] [Pg xii] Chance-Variations and Co-adaptation 97 Other Difficulties of the Chance-Variation Theory 99 Natural Selection 103 Impossible before Competition Existed 104 Co-operation and Competition 104 Protective Mimicry, Inexplicable by Chance-Variations and Natural Selection106 Innate Capacities of Life 109 Outline of Preceding Arguments 111 CHAPTER VI The Directive Theory of Evolution Nature’s Power of Response 115 Reinke’s Theory of Dominants 120 Cases of their Action in Evolution 123 Law and Directivity 128 Intelligence and Directivity 130 The Analogy of Social Evolution 131 The Analogy of Language 133 Synthetic Movement of the Cosmic Reason 137 Objections from Imperfect Adaptations and Regressive Forms Stated 143 Mechanical and Psychic Agencies, how Distinguished 146 Science versus ‘Mysticism’ 150 Reply to Objection from Imperfect Adaptations, etc. 152 Man, the Growing-point of Earthly Life 154 Immanence or Transcendence of the Cosmic Reason? 155 Man’s Relations to the Whole 157 PART II. ETHICS CHAPTER VII Law, Free Will, Personality Free Will and Determinism 161 The Determinist Position 163 The Free Will Position 164 Conditions necessary for Free Will 168 Has the Will an Ethical Bias? 169 Limitations of Free Will 172 Evolution of the Will 174 Free Will and Monism 176 Free Will and Brain-structure 177 Relations of Mind and Matter 186 Immortality 189 CHAPTER VIII The Ethical Criterion The Visible and the Invisible Worlds 194 Dualism and Monism 195 Monism and the Moral Law 198 The Hedonistic Basis of Morals 200 The Natural Basis of Morals 203 CHAPTER IX [Pg xiii] [Pg xiv] The Ethical Sanction The Individual and the Whole 208 A Scale of Motives 210 Conscience and its Commands, how respectively Derived 211 Results of Duty and of Self-indulgence Compared 212 The False and the True Asceticism 214 Ethics for Life: Implications of this Doctrine 220 Is Life Dependent on Matter? 222 The Cosmic Life gives Immortality to the Individual 225 And Demands his Allegiance 226 Ethics Originates in the Visible Order, but does not end there 228 Hence, Ethics is for Death as well as Life 229 The Martyrdoms of Socrates and of Christ 230 Outline of the Conclusions arrived at 233 PART III. ART CHAPTER X Art and Life Tolstoy’s Account of the Nature of Art 236 Of the Standard of Art 241 Of the Purpose of Art 241 Criticism of his Conclusions 245 Art, Man’s expression of Life 246 Art and Beauty 251 Order and Change as Principles of Life and Art 253 Classification of the Arts 254 Examples of the Presentative Arts—(a) Architecture 256 (b) Ornament 259 (c) Music 261 The Representative Arts—(a The Plastic Arts 265 (b) Dancing 270 The Evocative Art: Literature 271 The Union of Music and Poetry 272 Conclusion 273 APPENDIX A Sum ergo Cogito 275 APPENDIX B Co-operation and Competition 279 APPENDIX C Is Life worth Living? 282 APPENDIX D St. Francis the Poet 285 APPENDIX E Isabella and Claudio 288 Index 295 PARALLEL PATHS PART I: BIOLOGY [Pg xv] [Pg xvi] [Pg 1] P CHAPTER I THE ARGUMENT FROM DESIGN “The wisdom of the divine rule is apparent not in the perfection but in the improvement of the world.”—Lord Acton. ALEY’S Natural Theology though not by any means an epoch-making may perhaps be called an epoch-marking book. It was the crown of the endeavour of eighteenth-century religious philosophy to found a theology on the evidences of external nature. According to such exact knowledge of Nature’s operations as was then generally available, Paley’s attempt might well be thought to have succeeded. He opens his argument with a striking and effective illustration. He imagines a wayfarer crossing a heath who strikes his foot against a stone, and who asks himself how it came into being. Paley thinks he might be content with vaguely supposing that it was there ‘always.’ But suppose that what he had found at his foot was not a stone but a watch and that he now saw such an instrument for the first time. He would then certainly have not been so easily contented with an answer to the riddle of its existence. He would, if he examined it minutely, have observed that it was a structure intended for a certain purpose, and having all its parts arranged for that object, and mutually interdependent The different substances of which it was composed would be discovered to have each its special appropriateness for the fulfilling of some particular function in the economy of the whole. Though unacquainted with watches he would, if he was a man of sense and cultivation, infallibly conclude that he had before him an instrument intelligently constructed with a certain object in view—the object of measuring the flight of time. He would feel assured of this, even though he should find that the object of the mechanism were not attained with absolute accuracy, and even though there were some parts of it whose functions were not clear to him. The watch would be rightly regarded as a work of design; and the observer would be justified in arguing from it to the existence of a designer, endowed with the faculties of intelligence and conscious purpose, by whom the watch must have been put together. The rest of Paley’s Natural Theology is an application of this analogy to the question of the origin of the universe. Ranging over the whole field of animate and inanimate nature he points to instance after instance of what appears to be the minute and thoughtful adaptation of means to ends, the co-ordination of part with part in the interest of the whole, and he has no difficulty, from this point of view, in showing the world of nature to be a piece of mechanism far more wonderfully and ingeniously constructed than any watch, and bearing prima facie evidence of the most convincing kind of its construction by a Being possessed of intelligence, purpose and foresight precisely resembling those attributes as displayed by man, but vastly heightened and enlarged. As the watch must have been made by man, so a manlike being, endowed with the necessary powers and faculties, must be postulated as the maker of the material universe. And thus the existence of a God made in the image of man appeared to have been demonstrated to the satisfaction of eighteenth- century theology. But minds of real philosophic depth have always shrunk from pressing home deductions of this sort. They have felt that the matter is probably not quite so simple as it might appear on the surface, and they have recognised that if one is allowed to argue from the phenomena of nature to the qualities of the author of nature one cannot draw an arbitrary line including only those facts which testify to wisdom, power and goodness, and excluding from view all those which reveal imperfection of design and execution, or which would convict a man, if he were their author, of inhumanity and injustice. If the universe is really analogous to a watch one is entitled to examine it throughout as one would examine a watch. All watches testify to intelligence and design, but besides good watches there are bad ones, there are those which are made of cheap materials, rudely put together, with showy exteriors and unreliable works. Every watch, if examined by experts in mechanism, in art, and so forth, would reveal the characteristics of its designer and maker, and these characteristics would not always be admirable. They would rarely, in fact, be altogether admirable. If we apply these methods of inquiry to a universe which contains malarial mosquitoes, slave-making ants, snakes, earthquakes, and all the pests which blight and deform life without calling forth any strong or noble qualities to carry on the contest with them, we shall go where Paley certainly never intended to lead us, but we shall go there by Paley’s road. The fact is that these methods are altogether fantastic and inapplicable. The universe is not made like a watch. When we observe a human being or one of the higher animals we say, ‘He has such and such qualities; he is faithful, false, brave, cowardly, diligent, indolent, strong, weak, beautiful or ugly,’ but we do not think of referring his qualities back to certain attributes of an unknown maker of his physical and mental organism. A philosophy worthy of the name has always tended to regard the world as in some sense a vital organism, and has asked ‘What is it?’ rather than ‘What does it prove about some other being?’ “How green must be the maker of all grass” was quite a legitimate satire on all such attempts to deduce the qualities of a hypothetical creator from the phenomena of the universe. Thus the mistake of Paley and his school was fundamental. It was the mistake of seeking God in fragmentary phenomena—the same mistake, essentially, as that rebuked by Christ, by which every calamity or material blessing is regarded as a ‘judgment’ or a reward. His method, if applied with thorough-going consistency, destroys its own basis, for the One and the Many, the Whole and the Parts, cannot be apprehended at one and the same time by one and the same faculty of any human mind. Looking at phenomena alone, and thinking in that sphere, we cannot say that God made the world but rather that the world is becoming divine. Philosophically and religiously, God is all in all—historically, He is not the beginning, He is rather the end, the end in which the whole history is resumed. Paley’s elaborate argument was felt by the orthodox of his time to be called for, even though at this period his way of thinking was popular. The conception of the world as a vital organism was as yet, indeed, very vague, and unsupported [Pg 2] [Pg 3] [Pg 4] [Pg 5] by any detailed, scientific scrutiny of the facts of nature, but it was in the air—it had always been in the air; it always held the minds of cautious students back from a complete surrender to the facile but illusory way of thinking typified by Paley’s famous analogy of the universe and the watch. Bacon knew that species could be transformed by the action of a new environment.4 Goethe had a clear conception of the evolution theory, based on a study of organic structure. Erasmus Darwin, in 1794, had uttered the great and final word: “The world has been generated rather than created.”5 Lamarck’s Philosophie Zoologique was not published till 1809, nine years after Paley’s Natural Theology, but his conception of the development of special characteristics by habitual exercise and their transmission by inheritance had been freely mooted in Paley’s day, for Paley frequently takes occasion to combat it. Even the conception of natural selection as an agency in the formation of types of being may be traced in a fantastic form as far back as to Empedocles,6 while Plato, or whoever composed a striking couplet attributed to him in the Greek Anthology, had divined the plasticity of natural forms. “Time,” he wrote, “sways the whole world; time has power in its prolonged lapse to change the names and shapes, the nature and the destiny of things.”7 Fifty years after the appearance of Paley’s work, the grandson of Erasmus Darwin wrote ‘No thoroughfare’ on the entrance to Paley’s line of speculation, and closed it to mankind for ever. He did this in two ways—first by marshalling from his studies of comparative anatomy and of embryology an extraordinary volume of convincing evidence for the fact of the mutability of natural forms, and secondly by his attempt to establish a plausible method by which the change and development of organs and types might actually have taken place. The method, summed up in the phrases ‘natural selection’ and ‘survival of the fittest,’ was what really caught the attention of the world, and gave his doctrine the wings which carried it into almost every sphere of human thought. However we take it, it was certainly an immense contribution to the organization of knowledge, but whether it is really what it first seemed to be, the basic fact at the bottom of all the phenomena of evolution, is coming to look more and more doubtful in the light of later researches.8 This question will have to be considered later on in the course of this study, and in relation to its main inquiry, which is this: What precisely was the change in philosophic and religious outlook brought about by the full and final establishment of the doctrine of evolution? Where has evolution left the argument from design? Must we study nature as a mass of unrelated phenomena, or can we discern, through these, any fundamental unity to which they stand in organic relation; and if we can, what is the nature of this unity? It will be useful in the first place to have before us a typical specimen of Paley’s method. I shall choose as an example the case which he considered so striking that he deemed it almost sufficient in itself to bear the whole weight of his argument In his ninth chapter, ‘On the Muscles,’ he writes:— “The next circumstance which I shall mention under this head of muscular arrangement is so decisive a mark of intention, that it always appeared to me to supersede, in some measure, the necessity of seeking for any other observation upon the subject; and that circumstance is, the tendons which pass from the leg to the foot being bound down by a ligament to the ankle. The foot is placed at a considerable angle with the leg. It is manifest, therefore, that flexible strings, passing along the interior of the angle, if left to themselves, would, when stretched, start from it. The obvious preventive is to tie them down. And this is done, in fact. Across the instep, or rather just above it, the anatomist finds a strong ligament, under which the tendons pass to the foot. The effect of the ligament as a bandage can be made evident to the senses; for if it be cut, the tendons start up. The simplicity, yet the clearness of this contrivance, its exact resemblance to established resources of art, place it amongst the most indubitable manifestations of design with which we are acquainted. “There is also a further use to be made of the present example, and that is, as it precisely contradicts the opinion that the parts of animals may have been formed by what is called appetency, i.e. endeavour perpetuated and imperceptibly working its effect through an incalculable series of generations. We have here no endeavour but the reverse of it—a constant renitency and reluctance. The endeavour is all the other way. The pressure of the ligament constrains the tendons; the tendons react upon the pressure of the ligament. It is impossible that the ligament should ever have been generated by the exercise of the tendon, or in the course of that exercise, forasmuch as the force of the tendon perpendicularly resists the fibre, which confines it, and is constantly endeavouring not to form, but to rupture and displace, the threads of which the ligament is composed.” Paley’s account of the function of the annular ligament at the ankle is correct, and strikingly put. A similar ligament occurs at the wrist, and navvies who have hard muscular work to do in digging and shovelling are wont to reinforce this ligament and to keep it from rupture by a leather strap round the wrist. The strap performs exactly the same function as the ligament, and from Paley’s point of view one is as artificial, as much a ‘contrivance,’ as the other. But his point of view is wrong. He conceives the Creator as having at his disposal fully formed elements or materials—sinews, bones, ligaments, and the like—and assembling them into a working mechanism. In fact, however, none of these things is now what it was originally—time, as Plato says, has changed its “name and shape.” The annular ligaments are recognized by modern anatomists as having originated in special thickenings of the fascial sheaths of the adjoining muscles of the wrist and ankle. They had a function which was not originally connected with keeping down the long tendons that run along the interior angle of the leg and foot. Contractility, as biologists tell us, is a fundamental property of living protoplasm; and it is easy to imagine that, at the very beginning of the formation of muscular structure and bone articulation, two lines of contractile force might cross each other and thus permit the gradual evolution of the present arrangement, nature continually visiting with disability and extinction those individuals in whom the resisting power of the muscles which were eventually to form the annular ligament was unduly feeble, and giving a better chance of life, and of the propagation of their kind, to those in whom it was strong. The instance, in fact, is one of those in which the explanation of development by natural selection is most obvious and plausible. [Pg 6] [Pg 7] [Pg 8] [Pg 9] [Pg 10] [Pg 11] In his second paragraph Paley touches on the theory of “appetency,” the supposed tendency of natural structure to alter and adapt itself on the lines indicated by the actual exercise of function, and in consequence of that exercise. This is practically the theory since identified with the name of Lamarck. Paley scarcely does it justice, for no Lamarckian would suggest that a muscle could, in the course of its exercise, develop the ligament whose function is to restrain it. The ligament would be developed by its own exercise. But as Lamarckism will be discussed later on, the issue as between these rival theories need not be debated here. Let us set beside Paley’s argument on the annular ligament of the ankle a passage from a modern scientific work, Strasburger’s Text Book of Botany. It will introduce us, from the side of the strictest scientific observation and of the fullest acceptance of the evolution theory, to the same kind of problems as those discussed in Paley’s Natural Theology, and it will raise in a very distinct and unevadable fashion the question, what we are to think of the power manifested in the operations of Nature. In the introduction to his work, in which Dr. Strasburger had associated with him three other eminent German botanists, we find the following remarkable passage dealing with circumstances observed to exist in the ‘phylogenetic’ or tribal (as opposed to the ‘ontogenetic’ or individual) history of plant species: — “Although the great importance of natural selection in the development of the organic world has been fully recognised by most naturalists, the objection has been raised that it alone is not a sufficient explanation of all the different processes in the phylogeny of an organism. Attention has been called to such organs as would be incapable of exercising their function until in an advanced stage of development, and so could not originally have been of any advantage in a struggle for existence. How could natural selection tend to develop an organ which would be useless so long as it was still in a rudimentary condition? This objection has led to the supposition of an internal force residing in the substance of the organisms themselves and controlling their development in certain definite directions. Many naturalists indeed have gone so far as to affirm that only the less advantageous qualities have been affected by the struggle for existence, while the more advantageous have been uninfluenced by it”9 One can easily imagine what a modern Paley bent on reconciling orthodoxy and evolution would say to this. He would cry, Design, forethought, intelligence—here is the clearest evidence of it! And indeed there are many modern biologists who do not shrink from the admission that the processes of nature must ultimately be interpreted in terms of will or intention, not in terms of chance or blind mechanism. Thus, to the Darwinian argument that organs can be and are, demonstrably, formed by gradual adaptation to surrounding conditions without assuming the necessity of purposeful design, it is often replied that the very fact of adaptability is itself one of the strongest evidences if not of design at least of purpose. And J. v. Uexküll, who describes life as consisting essentially in the fact that it proceeds according to design (planmässig), has the following remarkable passage in his Experimental Biology10:— “When we look backwards, every phase in the process of development seems to us to have proceeded in a strictly causal manner from physico-chemical processes. But when we turn to look forward, it is certain that the physico-chemical processes if left to their own causality must immediately bring about the destruction of the organism. In fact, the clearest definition we can give of dying is to say of an organism that its processes now go on no longer teleologically (zweckmässig) but only causally.”11 Yet the modern Paley would be rash in arguing from facts like these (supposing them fully established) to the conscious, intelligent contrivance of a single foreseeing Mind. For very few things in this universe appear to be done as a presiding, conscious intelligence would do them. Conscious intelligence would not have evolved the giant armadillo only that the whole species might be destroyed by the sabre-toothed tiger, and would not have armed the sabre-toothed tiger for the attack on the armadillo in such a way that when he had exterminated the victim-species the formation of his teeth rendered it impossible for him to prey on any other animal.12 Conscious intelligence would not have allowed the relic of a disused organ, in the shape of the vermiform appendix, to be a constant source of danger and suffering to countless generations of men—danger against which no exercise of prudence or energy can secure them. Let us examine a couple of other crucial cases. The embryo of every mammalian animal is prepared in the womb for the life it is to live under wholly different conditions. Lungs are formed when there is no air for them to breathe, eyes when there is no light, a digestive system when nourishment is derived as yet direct from the mother’s blood. This capacity for anticipatory development during a period of gestation or incubation becomes absolutely necessary for the maintenance of life as soon as animals, ceasing to multiply by merely dividing in two, become more highly organized and have to devote special germ-cells to reproductive purposes. Here is certainly purpose, or, as I should prefer to call it, directivity—here we recognize what Reinke calls the X-factor in nature. But conscious, intelligent contrivance? We must recollect how many of these embryos are destined to perish at birth or before attaining any appreciable degree of independent life. Would not intelligence foresee that, and bring to birth only what was destined to endure? Again, there are certain species of butterflies which have put on a coloration and a form the effect of which is to aid them in evading the attacks of birds. They were not created so; they have become so; and the precise manner of the becoming will be fully discussed in a later chapter. Let us assume for the moment that this adaptation did not occur by a series of lucky accidents or by any merely mechanical process. Are we, then, bound to attribute it to intelligent contrivance? The question will be best answered by simply putting a case which admits of no doubt. Suppose there were an island in which there were no birds, except such as prey on fishes or on each other, but never on insects. The butterflies on this island, if there were any, would certainly show no trace of protective form or coloration. But at some time or other insect-eating birds might be introduced to the island, as the English sparrow has been introduced in [Pg 12] [Pg 13] [Pg 14] [Pg 15] [Pg 16] Australia. Then, if the extermination of the butterflies did not proceed too rapidly, we might expect, in the course of generations, to see protective adaptations assumed. But could we expect to see them assumed in anticipation of the advent of the destroyers? We could not. Naturalists, however much they may differ, as they do differ, upon the question as to how protective adaptations actually take place, would all agree that they could not possibly take place in anticipation of needs not yet present. If they did, we should have a miracle, and where miracle comes in knowledge goes out. The cases where conscious, intelligent contrivance would be unmistakably recognizable are just the cases which never occur. The signal service rendered by the champions of the evolution theory, Quos nec fama Deûm, nec fulmina, nec minitanti Murmure compressit Cœlum, is that they conquered the realm of organic nature for true knowledge, and gave the drama of its development a new and profound interest, by showing with an uncompromising courage only equalled by the extraordinarily minute and patient research which justified it, that the apparent instances of divine contrivance with which nature teems must be explained by the responsiveness, the adaptability, of living protoplasm. Needless to say, this demonstration does not in the least disprove the existence of God as a supreme, conscious, personal Intelligence.13 But it does forbid us to deduce the existence of such a Being from the observation of natural phenomena. A living, developing universe has been set in the place of a Divine Mechanician operating on dead matter. The question, what conception we are to form of the forces of evolution, will be more fully discussed in the succeeding chapters on Biology, as a foundation for views which will afterwards be put forward in relation to Ethics and to Art. But first we must clear the ground a little by considering what it really is that we are to study, and if it be possible to study it at all. Nature-study if it is to be possible must begin, and if it is to be fruitful must end, in something which is not strictly the study of nature, but which we call Philosophy. One of the most brilliant examples of that union of philosophic speculation with nature-study which is so marked a feature of the German thought of our day is H. von Keyserling’s work, The Structure of the World.14 Keyserling begins by laying it down as a postulate of thinking that “The Universe is a rounded, inwardly coherent Whole.” A postulate of thinking this is indeed, and more than that—it is a postulate of living. If under all the variety and apparent discontinuity of the universe there does not lie One all-pervading and unifying Power, then meditation and action are alike vain, for none can tell the hour when some incursion of the unknown may not shatter our cosmos into chaos, or leave us in a new universe with the edifice of our past experience, the familiar home of the spirit, lying in ruins around us. Every one assumes, consciously or unconsciously, that there is such a Power, that the universe is One, that however mysterious, however little known or understood it may be, it is not essentially deceptive or incalculable. The savage and the philosopher alike assume this, and act upon the assumption. It is perhaps possible not merely to assume but to prove it. For let us try to imagine what would be the case if it were not true. If the Principle, the ultimate Reality of the universe, be not one it must be at least dual. There must be not less than two principles. Now there are only three ways in which these two principles—and what we say will hold good for any greater number—can be related to each other. They must either (1) be identical, or (2) they must be complementary, each possessing something which the other is lacking in, or (3) they must negate each other and be mutually contradictory and exclusive. But two absolutely identical principles, if we can conceive such a thing, are indistinguishable from one. Two or more complementary principles, again, make up, when taken together, but a single whole, as in the Christian Trinity. Therefore if the universe be really dual, its two principles must negate and contradict each other. Now these two hostile principles must either be equal in force or one must be more powerful than the other. In the latter event, seeing that they divide between them the sum total of existence and thus stand in naked and essential antagonism, with no place for evasion, and no auxiliary or modifying forces to call in, it follows of necessity that if one surpassed the other by even the smallest conceivable excess, it must, in eternity, master it and reduce it to impotence. So by this road we come back to unity again. If, however, we suppose our two forces to be co-equal and co-eternal, we have to ask ourselves what we mean by supposing them to be antagonistic. Antagonism can only arise when there is action. But two equal forces acting in direct contradiction to each other must mutually cancel each other, and the result is zero. On such an hypothesis the universe could never have come into being. It may also be pointed out that the hypothesis itself seems to be irrational. For action means the production of a change of some kind, change in the nature or situation of objects. But if one of our forces is producing changes of a certain kind and the other producing changes of another kind, then they are not contradictory but complementary. The only real antagonism between two ultimate principles must consist in one of them being identified with action, change, life, the other with immobility and death. But a principle of immobility and death, if there could be such a thing, could not also be a principle of action, not even of destructive action, for to act at all would be a contradiction of its own nature. It would begin and end in total inaction, and the field would be clear for the other Power, just as if nothing else existed. It follows that, in the living and moving universe around us, there cannot be any such thing as an active principle of destruction and death. We are obliged to perceive Being under the guise of Becoming and Becoming under the guise of Change and Progression. This is a process taking place in the visible and temporal order of things and capable, under certain conditions, of partial arrest or retrogression. But the Whole, regarded as a whole, can be and can contain nothing but life, and must under all its diversity (which is an aspect of life) be One. It is this unity which alone can make intelligible and rational the diversity of which every study of life must treat. It is my endeavour in the present work to bring into clear light some important aspects of this unity, as revealed in the inter-relations of the parts of which, to our eyes, it seems to be composed.15 [Pg 17] [Pg 18] [Pg 19] [Pg 20] [Pg 21] I CHAPTER II THE WHEEL OF LIFE I heard them in their sadness say The earth rebukes the thought of God; We are but embers wrapped in clay, A little nobler than the sod. But I have touched the lips of clay; Mother, thy rudest sod to me Is thrilled with fire of hidden day, And haunted by all mystery.—A.E. T has long been known that no definite line of demarcation can be drawn between the animal and the vegetable worlds. There are lowly organisms which cannot be decisively referred either to the one or to the other. It has been more recently shown that the apparently more strongly marked line between the living and the non-living also grows wavering and indistinct in places. Metals are known to respond to stimuli and to show ‘fatigue’ in a manner commonly attributed only to the nervous system of animals,16 while some of the phenomena of crystallization strongly resemble those of vitality.17 Le Dantec has uttered the latest word of physics on this subject, where he insists on the “absence of all essential difference and all absolute discontinuity between living and non-living matter.”18 Indeed, one may say of nature-study in general, that if, as Plato said, the beginning of knowledge is in definitions and classification, the end of it lies in getting rid of them. There is probably no such thing as a universally applicable definition of any group of natural phenomena. There is certainly no condition of matter of which we are entitled to say that Life is impossible without it. Still, natural groups have well-marked central features, even if at their margins they melt into something else. Now the things which in the ordinary sense of the word we call Living are marked by these characters: Their chemical constituents are always compounds of carbon. These compounds are what is called ‘unstable’—they ‘consume’ or disintegrate by combining with oxygen in air or water. In this process organisms obtain the energy necessary for assimilation and growth. The above characters (carbon-compounds, chemical instability, and faculty of assimilation) apply to plants and animals alike. But we find, in general, that plants are able, from inorganic mineral constituents such as carbonic acid, water, nitrates, sulphates, etc.,19 to build up the organic compounds like proteid, albumin, the carbohydrates, alcohol, fat; while animals use for their nourishment not the inorganic substances but only organic compounds already formed by plants or by other animals. A well-developed vegetable world must therefore, it would seem, have preceded the appearance of animal life on the globe.20 It was long believed that these organic compounds of carbon could only be formed by the vital action of living vegetation. One of the epochs in the history of modern chemistry has been the demonstration (first by Wöhler, in 1828,) that many of them can be produced in the laboratory from inorganic chemical constituents. But this is only effected by circuitous and difficult ways, and—a circumstance often overlooked—it only resembles what is accomplished in nature if we include under nature the directive agency represented by the chemist himself, as well as the materials with which he deals. The characteristic colour of living vegetation is green. This is also the rarest of colours among the higher animals.21 It is due in vegetables to the presence in their cells of grains of the substance known as chlorophyll, which very few animals possess or have need of. It is developed normally under the action of sunlight, and plays a most important part in the economy of the plant. The usual method by which any organism obtains the energy necessary for its vital functions is through the oxidization, i.e. the slow burning, of its substance, by combination with the oxygen of the air. The process is to all intents the same as the more rapid oxidization, under great heat, of coal in a steam-engine. If a plant can obtain sugar, which oxidizes easily in contact with atmospheric oxygen, it has thus a fund of energy to draw on for all the processes of its life. Now sugar is composed of carbon and water. Carbon exists in the air, in combination with oxygen, in the form known as carbonic acid. Chlorophyll, in some way as yet unexplained, enables plants, when acted upon by light, to take in carbonic acid from the air and to disintegrate it into its constituents, carbon and oxygen. The oxygen disappears again in the air, and the released carbon combines with water in the plant to form sugar,22 thus giving the plant its needed store of potential energy. All it does with this energy is to live, grow, and reproduce its kind; till at length a time comes when the assimilative energy weakens relatively to the forces of decay, and the plant dies; it is again resolved into the chemical constituents from which it was built up; but not without having passed on the flame of life to burn afresh in its descendants. Plants which have no chlorophyll, like certain bacteria and moulds, and which, therefore, cannot decompose the carbonic acid in the air for their nourishment, offer an interesting example of the manner in which Nature contrives to get her way, if not by the normal instruments, then by the utilization of others. They acquire their first store of energy sometimes like animals, from other organic compounds, or they take carbon from acetates and tartrates. The nitro- bacteria appear to depend on ammonia derived from decaying animal matter, and the moulds draw their energy from sugar, which (as in our jams, etc.) they find already formed. There are other plants, such as the fly-eating Drosera, which feed upon organic substances with the aid of digestive juices, exactly as animals do; and there are animals, such as Hydra and others, of very primitive form,23 which produce chlorophyll and are thereby enabled, like plants, to feed upon carbonic acid. The distinction therefore which has been drawn between the two kingdoms as regards their modes of nourishment must, like other definitions of natural groups, [Pg 22] [Pg 23] [Pg 24] [Pg 25] [Pg 26] be taken to apply to central and typical forms and not to constitute a distinct boundary line. Allowing for these exceptional cases, we may say broadly that the wheel of life makes its full circle in passing from inorganic matter through plants to animals and thence back to gases and minerals again. The process of taking in fresh matter, transforming it chemically into living tissue, and thus repairing the waste occasioned by the decomposition of the carbon-compounds of that tissue, is technically known as Metabolism. This is the typical and characteristic function of organic life. Now this function of living matter, or Protoplasm, depends upon two elements: first, its Substance; secondly, its Structure. As regards the former, we are in this serious difficulty, that living matter can never be chemically investigated by any means at present known, for it dies immediately in presence of any of the reagents which are used to ascertain its chemical composition. It is known that there are no elementary substances in living matter which are not also found in the world of inorganic matter, but it is also known that their synthetic combination in living is different from that which obtains in dead tissue,24 and it is precisely through this factor—that of the grouping or synthesis of elements—that the most remarkable forms of energy are developed. The secret of life, therefore, cannot be stated in terms of chemistry, because we cannot surprise the secret of its chemical synthesis. Even if we could do this we should still be unable to say why certain syntheses should appear in living matter and resolve themselves into others at death. We find, however, in the investigation of organic tissue (plant or animal) by such means as are available, that one substance is common to all the organic and is never found (as such) in the inorganic world. This is called Proteid. It is composed of five elements—Carbon, Hydrogen, Sulphur, Nitrogen, and Oxygen, which are combined in proportions not at present ascertained. Subject to the limitations just set forth we may say that proteid is the essential stuff of organic tissue. The two other usual (though not, like proteid, universal) constituents of this tissue—the Carbohydrates (sugar, starch, etc.) and the Fats—are, it is believed, formed partly from the products of the metabolism of proteid. When we come to deal with the essential Structure of life we are in much the same difficulty as that in which we found ourselves in investigating its chemical Substance. We can observe living cells under the microscope, but the most powerful microscope has never reached the limits beyond which we can say that there is no structure. There is another limitation too. The microscope has revealed the fact that all living tissue is made up of cells, but the internal structure of the cell, beyond the fact that it is composed of a fluid substance within which a darker coloured nucleus is usually embedded, could not be ascertained until the recent device of staining the object with aniline dyes had been thought of. Different substances in the cell are found to take these dyes differently, and thus a world of structure of the most singular kind has been revealed in what formerly seemed a simple, semi-transparent fluid. Some parts of this structure hover, as it were, upon the very edge of perceptibility, the most suitable dyes for bringing them under observation not having been as yet discovered. There may be others which no dye ca...