THE SACRED BEETLE & OTHER GREAT ESSAYS IN SCIENCE. Chosen and Introduced by Martin Gardner

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1 THE SACRED BEETLE & OTHER GREAT ESSAYS IN SCIENCE Chosen and Introduced by Martin Gardner From Darwin on evolution to Einstein on relativity covering subjects as diverse as science and literature, the sea, the laws of physics, the beautiful woman, logic, the bee, and the moon, this is a lively and lucid collection of essays by thirty-two leading interpreters of science. The essays are drawn together and provided with an entertaining and perceptive commentary by Martin Gardner, who explains that his selection was governed not by a desire to teach, or to bring us up to date on new trends and discoveries, but 'to spread before the reader, whether his interest in science be passionate or mild, a sumptuous feast of great writing--absorbing, thought-disturbing pieces that have something important to say about science and say it forcibly and well'. His explanatory and biographical sketches make this book not only a rich collection of good reading, but also an informal history of the people and ideas that have shaped our culture and moulded our everyday lives. Martin Gardner is a mathematician whose numerous books on science, mathematics, and philosophy include Science: Good, Bad and Bogus and Order and Surprise (both available in Oxford Paperbacks). In 1983 he was named Science Writer of the Year by the American Institute of Physics. Contents FRANCIS BACON The Sphinx (1609) CHARLES DARWIN Recapitulation and Conclusion (1859) JOHN DEWEY The Influence of Darwinism on Philosophy (1909) STEPHEN JAY GOULD Nonmoral Nature (1982) WILLIAM JAMES The Problem of Being (1911) HAVELOCK ELLIS What Makes a Woman Beautiful (1905) JEAN HENRI FABRE The Sacred Beetle (1918) GILBERT KEITH CHESTERTON The Logic of Elfland (1908)

2 CARL SAGAN Can We Know The Universe? Reflections on a Grain of Salt ( 1979) JOSEPH WOOD KRUTCH The Colloid and the Crystal (1950) JOSE ORTEGA Y GASSET The Barbarism of "Specialization" (1932) THOMAS HENRY HUXLEY Science and Culture (1893) JOHN BURROUGHS Science and Literature (1889) ISAAC ASIMOV Science and Beauty (1983) ERNEST NAGEL Automation (1955) JONATHAN NORTON LEONARD Other-Worldly Life (1953) J. ROBERT OPPENHEIMER Physics in the Contemporary World (1955) ALFRED NORTH WHITEHEAD Religion and Science (1925) JOHN DOS PASSOS Proteus (1930) JULIAN HUXLEY An Essay on Bird-Mind (1923) ARTHUR STANLEY EDDINGTON The Decline of Determinism ( 1934 ) ALDOUS HUXLEY Science in the Brave New World (1932) RACHEL CARSON The Sunless Sea (1951) MAURICE MAETERLINCK The Nuptial Flight (1901) H. G. WELLS The New Source of Energy (1914) Science and Ultimate Truth (1931) LAURA FERMI Success (1954) SAMUEL GOUDSMIT The Gestapo in Science (1947) ROBERT LOUIS STEVENSON

3 Pan's Pipes (1876) SIGMUND FREUD Dreams of the Death of Beloved Persons ( 1900) BERTRAND RUSSELL The Science to Save Us from Science (1950) The Greatness of Albert Einstein (1955) ALBERT EINSTEIN E = mc 2 (1946) LEWIS THOMAS Seven Wonders (1983) Preface IN 1955 Herbert Alexander, then president of Pocket Books, asked me to edit an anthology to be titled Great Essays in Science. The paperback edition (it never saw hard covers) came out in This expanded and revised edition, with its new title, brings the book back in print after a lapse of more than a decade. Most of the small changes made in the introductions have been occasioned by the deaths of contributors. The computer revolution has moved much faster than anyone anticipated when Ernest Nagel wrote about automation, but I am allowing that essay to remain, with my introduction unaltered, because the coming of the industrial robots has made Nagel's piece as timely and as accurate as it was in The only selection I removed was a long chapter on the moon that first appeared in Sir Robert Ball's classic work of 1885, The Story of the Heavens. Although this chapter was written more than seventy years before I put it in my anthology, it contained surprisingly little that was then out of date, and indeed one can still learn much from it. "Significant new knowledge." I wrote in my introduction, "will have to wait upon the first lunar explorers." I was right in predicting that "soon the artificial satellites will be whirling around the earth" and that the moon is "certain to be the first spot visited by our spacemen." Unfortunately, I added another guess that was far too cautious. "Our children." I wrote, "may well live to see a rocket ship circle or land on the moon and return." Four new essays have been added. I wish there could have been more, but the size of a book is limited and I decided with reluctance to limit my choices to essays by four Americans who began their distinguished sciencewriting careers after the date of the first edition of this collection: Isaac Asimov, Stephen Jay Could, Carl Sagan. and Lewis Thomas. By an

4 astonishing coincidence, all four of these men grew up in Brooklyn! I like to think of the Brooklyn Bridge as a giant symbol of the joining of C. P. Snow's "two cultures." It is a bridge that all four writers travel back and forth in their books as easily and often as they must have once travelled back and forth between Manhattan and Brooklyn. As I said in my original preface, I had hoped that every major branch of science might be represented in this anthology, but it was not possible. Medicine and the social sciences, for example. are not here, although many of the book's essays raise momentous political questions. A limit also had to be placed on the age of the selections. For many reasons I decided to include nothing published earlier than 1859, the pivotal year of Darwin's Origin of Species. (The prologue by Francis Bacon is the sole exception.) Only the piece by Havelock Ellis has been cut. The others are reprinted in full, with no textual alterations. As a literary form the essay has always had irresponsible boundaries, and in this collection its definition becomes no clearer. There are "essays" here that are chapters, or segments from chapters, not written to be read apart from the book in which they first appeared. Several were originally lectures. Two are from works of fiction. Some are brief enough to be called sketches, others long enough to be called treatises. Some are heavy with scientific erudition, others glance at science casually over a shoulder. Some are wandering, informal expressions of opinion; others labour a thesis with the systematic vigour of a medieval schoolman. Even the cardinal rule that a great essay must be beautifully written has been violated in one or two instances. Nothing could be further from my intent than to hand the reader a volume designed primarily to teach him science or bring him up to date on the latest trends and discoveries. There is no end to the making of such anthologies and even the best of them have a distressing way of becoming out of date before the pages are bound. Rather, the purpose of this book is to spread before the reader, whether his or her interest in science be passionate or mild, a sumptuous feast of great writing--absorbing, thought-disturbing pieces that have some- thing important to say about science and say it forcibly and well. Martin Gardner

5 Prologue FRANCIS BACON The Sphinx SPHINX, says the story, was a monster combining many shapes in one. She had the face and voice of a virgin, the wings of a bird, the claws of a griffin. She dwelt on the ridge of a mountain near Thebes and infested the roads, lying in ambush for travellers, whom she would suddenly attack and lay hold of; and when she had mattered them, she propounded to them certain dark and perplexing riddles, which she was thought to have obtained from the Muses. And if the wretched captives could not at once solve and interpret the same, as they stood hesitating and confused she cruelly torn them to pieces. Time bringing no abatement of the calamity, the Thebans offered to any man who should expound the Sphinx's riddles (for this was the only way to subdue her) the sovereignty of Thebes as his reward. The greatness of the prize induced (Edipus, a man of wisdom and penetration, but lame from wounds in his feet, to accept the condition and make the trial: who presenting himself full of confidence and alacrity before the Sphinx, and being asked what kind of animal it was which was born four-footed, afterwards became two- footed, then three-footed, and at last four-footed again, answered readily that it was man; who at his birth and during his infancy sprawls on all fours, hardly attempting to creep; in a little while walks upright on two feet; in later years leans on a walking-stick and so goes as it were on three; and at last in extreme age and decrepitude, his sinews all failing, sinks into a quadruped again, and keeps his bed. This was the right answer and gave him the victory; whereupon he slew the Sphinx; whose body was put on the back of an ass and carried about in triumph; while himself war made according to compact King of Thebes. The fable is an elegant and a wise one, invented apparently in allusion to Science; especially in its application to practical life. Science, being the wonder of the ignorant and unskilful, may be not absurdly caned a monster. In figure and aspect it is represented as many-shaped, in illusion to the immense variety of matter with which it deals. It is said to have the face and voice of a woman, in respect of its beauty and facility of utterance. Wings are added because the sciences and the discoveries of science spread and 9 abroad in on instant; the communication of knowledge being like that of one candle with another, which lights up at once, Claws, sharp and hooked, are ascribed to it with great elegance, because the axioms and arguments of science penetrate and hold fast the mind, so that it has no means of evasion

6 or escape; a point which the sacred philosopher also noted: The words of the wise are as goads, and as nails driven deep in. Again, all knowledge may be regarded as having its station on the heights of mountains; for it is deservedly esteemed a thing sublime and lofty, which looks down upon ignorance as from an eminence, and has moreover a spacious prospect on every side, such as we find on hill-tops. It is described as infesting the roads, because at every turn in the journey or pilgrimage of human life, matter and occasion for study assails and encounters us. Again Sphinx proposes to men a variety of hard questions and riddles which she received from the Muses. In these, while they remain with the Muses, there is probably no cruelty; for so long as the object of meditation and inquiry is merely to know, the understanding is not oppressed or straitened by it, but is free to wander and expatiate, and finds in the very uncertainty of conclusion and variety of choice a certain pleasure and delight; but when they pass from the Muses to Sphinx, that is from contemplation to practice, whereby there is necessity for present action, choice, and decision, then they begin to be painful and cruel; and un- less they be solved and disposed of they strangely torment and worry the mind, pulling it first this way and then that, and fairly tearing it to pieces. Moreover the riddles of the Sphinx have always a twofold condition attached to them; distraction and laceration of mind, if you fail to solve them; if you succeed, a kingdom. For he who understands his subject is master of his end; and every workman is king over his work. Now of the Sphinx's riddles there are in all two kinds; one concerning the nature of things, another concerning the nature of man; and in like manner there are two kinds of kingdom offered as the reward of solving them; one over nature, and the other over man. For the command over things natural,- over bodies, medicines, mechanical powers, and infinite other of the kind-is the one proper and ultimate end of true natural philosophy; however the philosophy of the School, content with what it finds, and swelling with talk, may neglect or spurn the search after realities and works. But the riddle proposed to Edipus, by the solution of which he became King of Thebes, related to the nature of man; for whoever has a thorough insight into the nature of man may shape his fortune almost as he will, and is horn for empire; as was well declared concerning the arts of the Romans,- Be thine the art, O Rome, with government to rule the nations, And to know whom to spare and whom to abate, And settle the condition of the world.

7 And therefore it fell out happily that Augustus Caesar, whether on purpose or by chance, used a Sphinx for his seal. For he certainly excelled in the art of politics if ever man did; and succeeded in the course of his life in solving most happily a great many new riddles concerning the nature of man, which if he had not dexterously and readily answered he would many times have been in imminent danger of destruction. The fable adds very prettily that when the Sphinx was subdued, her body was laid on the back of an ass: for there is nothing so subtle and abstruse, but when it is once thoroughly understood and published to the world, even a dull wit can carry it. Nor is that other point to be passed over, that the Sphinx was subdued by a lame man with club feet; for men generally proceed too fast and in too great a hurry to the solution of the Sphinx's riddles; whence it follows that the Sphinx has the better of them, and instead of obtaining the sovereignty by works and effects, they only distract and worry their minds with disputations.

8 CHARLES DARWIN AT LAST gleams of light have come," Darwin wrote in 1844 to a friend, "and 1 am almost convinced (quite contrary to the opinion I started with) that species are not (it is like confessing a murder) immutable." Charles Darwin ( ) was a man of extraordinary patience and humility. "Almost convinced," he wrote, and this after more than ten years of painstaking labour in the gathering of relevant facts, and fourteen years before he felt compelled to publish his views! The theory of evolution had been pro- pounded before; but not until Darwin issued his Origin of Species, in 1859, had such a mountainous mass of evidence been brought together into one orderly, irrefutable argument. In truth, a murder of a sort had been committed. The book dealt a mortal blow to prevailing interpretations of the opening chapters of Genesis, and Christian orthodoxy was never the same again. Darwin himself, as a young biologist aboard H.M.S. Beagle, was so thoroughly orthodox that the ship's officers laughed at his propensity for quoting Scripture. Then "disbelief crept over me at a very slow rate," he recalled, "but was at last complete. The rate was so slow that I felt no distress." The phrase "by the creator," in the final sentence of the selection chosen here, did not appear in the first edition of Origin of Species. It was added to the second edition to conciliate angry clerics. Darwin later wrote, "I have long since regretted that I truckled to public opinion and used the Pentateuchal term of creation, by which I really meant 'appeared' by some wholly unknown process. Darwin knew nothing, of course, of modern mutation theory. He thought environment could modify an individual organism and that these modifications could be communicated through the blood stream to the germ plasm and so passed on to the next generation. This Lamarckian aspect of his views has long been discarded, but natural selection by survival of the fittest remains the indispensable cornerstone of the evolutionary process. "There is grandeur in this view of life," Darwin writes. And there is grandeur also in the unpretentious sentences of this great and unassuming man.

9 CHARLES DARWIN Recapitulation and Conclusion I HAVE now recapitulated the facts and considerations which have thoroughly convinced me that species have been modified, during a long course of descent. This has been effected chiefly through the natural selection of numerous successive, slight, favourable variations; aided in an important manner by the inherited effects of the use and disuse of parts; and in an unimportant manner, that is in relation to adaptive structures, whether past or present, by the direct action of external conditions, and by variations which seem to us in our ignorance to arise spontaneously. It appears that I formerly underrated the frequency and value of these latter forms of variation, as leading to permanent modifications of structure independently of natural selection. But as my conclusions have lately been much misrepresented, and it has been stated that I attribute the modification of species exclusively to natural selection, I may be permitted to remark that in the first edition of this work, and subsequently, I placed in a most conspicuous position--namely, at the close of the Introduction --the following words: "I am convinced that natural selection has been the main but not the exclusive means of modification." This has been of no avail. Great is the power of steady misrepresentation; but the history of science shows that fortunately this power does not long endure. It can hardly be supposed that a false theory would explain, in so satisfactory a manner as does the theory of natural selection, the several large classes of facts above specified. It has recently been objected that this is an unsafe method of arguing; but it is a method used in judging of the common events of life, and has often been used by the greatest natural philosophers. The undulatory theory of light has thus been arrived at; and the belief in the revolution of the earth on its own axis was until lately supported by hardly any direct evidence. It is no valid objection that science as yet throws no light on the far higher problem of the essence or origin of life. Who can explain what is the essence of the attraction of Gravity? No one now objects to following out the results con- sequent on this unknown element of attraction; notwithstanding that Leibnitz formerly accused Newton of introducing "occult qualities and miracles into philosophy. I see no good reason why the views given in this volume should shock the religious feelings of any one. It is satisfactory, as showing how transient

10 such impressions are, to remember that the greatest discovery ever made by man, namely, the law of the attraction of gravity, was also attacked by Leibnitz, "as subversive of natural, and inferentially of revealed, religion." A celebrated author and divine has writ- ten to me that "he has gradually learnt to see that it is just as noble a conception of the Deity to believe that He created a few original forms capable of self-development into other and needful forms, as to believe that He required a fresh act of creation to supply the voids caused by the action of His laws." Why, it may be asked, until recently did nearly all the most eminent living naturalists and geologists disbelieve in the mutability of species? It cannot be asserted that organic beings in a state of nature are subject to no variation; it cannot be proved that the amount of variation in the course of long ages is a limited quantity; no clear distinction has been, or can be, drawn between species and well-marked varieties. It cannot be maintained that species when intercrossed are invariably sterile, and varieties invariably fertile; or that sterility is a special endowment and sign of creation. The belief that species were immutable productions was almost unavoidable as long as the history of the world was thought to be of short duration; and now that we have acquired some idea of the lapse of time, we are too apt to assume, without proof, that the geological record is so perfect that it would have afforded us plain evidence of the mutation of species, if they had undergone mutation. But the chief cause of our natural unwillingness to admit that one species has given birth to other and distinct species, is that we are always slow in admitting great changes of which we do not see the steps. The difficulty is the same as that felt by so many geologists, when Lyell first insisted that long lines of inland cliffs had been formed, and great valleys excavated, by the agencies which we see still at work. The mind cannot possibly grasp the full meaning of the term of even a million years; it cannot add up and perceive the full effects of many slight variations, accumulated during an almost infinite number of generations. Although I am fully convinced of the truth of the views given in this volume under the form of an abstract, I by no means expect to convince experienced naturalists whose minds are stocked with a multitude of facts all viewed, during a long course of years, from a point of view directly opposite to mine. It is so easy to hide our ignorance under such expressions as the "plan of creation," "unity of design," &C., and to think that we give an explanation when we only re-state a fact. Any one whose disposition leads him to attach more weight to unexplained difficulties than to the explanation of a certain number of facts will certainly reject the theory. A few naturalists, endowed with much flexibility of mind, and who have already

11 begun to doubt the immutability of species, may be influenced by this volume; but I look with confidence to the future,-to young and rising naturalists, who will be able to view both sides of the question with impartiality. Whoever is led to believe that species are mutable will do good service by conscientiously expressing his conviction; for thus only can the load of prejudice by which this subject is overwhelmed be removed. Several eminent naturalists have of late published their belief that a multitude of reputed species in each genus are not real species; but that other species are real, that is, have been independently created. This seems to me a strange conclusion to arrive at. They admit that a multitude of forms, which till lately they themselves thought were special creations, and which are still thus looked at by the majority of naturalists, and which consequently have all the external characteristic features of true species,-they admit that these have been produced by variation, but they refuse to extend the same view to other and slightly different forms. Nevertheless they do not pretend that they can define, or even conjecture, which are the created forms of life, and which are those produced by secondary laws. They admit variation as a vera causa in one case, they arbitrarily reject it in another, without assigning any distinction in the two cases. The day will come when this will be given as a curious illustration of the blindness of preconceived opinion. These authors seem no more startled at a miraculous act of creation than at an ordinary birth. But do they really believe that at innumerable periods in the earth's history certain elemental atoms have been commanded suddenly to flash into living tissues? Do they believe that at each supposed act of creation one individual or many were produced? Were all the infinitely numerous kinds of animals and plants created as eggs or seed, or as full grown? And in the case of mammals, were they created bearing the false marks of nourishment from the mother's womb? Undoubtedly some of these same questions cannot be answered by those who believe in the appearance or creation of only a few forms of life, or of some one form alone. It has been maintained by several authors that it is as easy to believe in the creation of a million beings as of one; but Maupertuis' philosophical axiom "of least action" leads the mind more willingly to admit the smaller number; and certainly we ought not to believe that innumerable beings within each great class have been created with plain, but deceptive, marks of descent from a single parent. As a record of a former state of things, I have retained in the foregoing paragraphs, and elsewhere, several sentences which imply that naturalists believe in the separate creation of each species; and I have been much censured for having thus expressed myself. But undoubtedly this was the general belief when the first edition of the present work appeared. I formerly

12 spoke to very many naturalists on the subject of evolution, and never once met with any sympathetic agreement. It is probable that some did then believe in evolution, but they were either silent, or expressed themselves so ambiguously that it was not easy to understand their meaning. Now things are wholly changed, and almost every naturalist admits the great principle of evolution. There are, however, some who still think that species have suddenly given birth, through quite unexplained means, to new and totally different forms: but, as I have attempted to show, weighty evidence can be opposed to the admission of great and abrupt modifications. Under a scientific point of view, and as leading to further investigation, but little advantage is gained by believing that new forms are suddenly developed in an inexplicable manner from old and widely different forms, over the old belief in the creation of species from the dust of the earth. It may be asked how far I extend the doctrine of the modification of species. The question is difficult to answer, because the more distinct the forms are which we consider, by so much the arguments in favour of community of descent be come fewer in number and less in force. But some arguments of the greatest weight extend very far. All the members of whole classes are connected together by a chain of affinities, and all can be classed on the same principle, in groups subordinate to groups. Fossil remains sometimes tend to fill up very wide intervals between existing orders. Organs in a rudimentary condition plainly show that an early progenitor had the organ in a fully developed condition; and this in some cases implies an enormous amount of modification in the descendants. Throughout whole classes various structures are formed on the same pattern, and at a very early age the embryos closely resemble each other. Therefore I cannot doubt that the theory of descent with modification embraces all the members of the same great class or kingdom. I believe that animals are descended from at most only four or five progenitors, and plants from an equal or lesser number. Analogy would lead me one step farther, namely, to the belief that all animals and plants are descended from some one prototype. But analogy may be a deceitful guide. Nevertheless all living things have much in common, in their chemical composition, their cellular structure, their laws of growth, and their liability to injurious influences. We see this even in so trifling a fact as that the same poison often similarly affects plants and animals; or that the poison secreted by the gall-fly produces monstrous growths on the wild rose or oak- tree. With all organic beings, excepting perhaps some of the very lowest, sexual reproduction seems to be essentially- similar. With all, as far as is at present known, the germinal

13 vesicle is the same; so that all organisms start from a common origin. If we look even to the two main divisions--namely, to the animal and vegetable kingdoms--certain low forms are so far intermediate in character that naturalists have disputed to which kingdom they should be referred. As Professor Asa Gray has remarked, "the spores and other reproductive bodies of many of the lower algae may claim to have first a characteristically animal, and then an unequivocally vegetable existence." Therefore, on the principle of natural selection with divergence of character, it does not seem incredible that, from some such low and intermediate form, both animals and plants may have been developed; and, if we admit this, we must likewise admit that all the organic beings which have ever lived on this earth may be descended from some one primordial form. But this inference is chiefly grounded on analogy, and it is immaterial whether or not it be accepted. No doubt it is possible, as Mr. G. H. Lewes has urged, that at the first commencement of life many different forms were evolved; but if so, we may conclude that only a very few have left modified descendants. For, as I have recently remarked in regard to the members of each great kingdom, such as the Vertebrata, Articulata, &c., we have distinct evidence in their embryological, homologous, and rudimentary structures, that within each kingdom all the members are descended from a single progenitor. When the views advanced by me in this volume, and by Mr. Wallace, or when analogous views on the origin of species are generally admitted, we can dimly foresee that there will be a considerable revolution in natural history. Systematists will be able to pursue their labours as at present; hut they will not be incessantly haunted by the shadowy doubt whether this or that form be ii true species. This, I feel sure and I speak after experience, will be no slight relief. The endless disputes whether or not some fifty species of British brambles are good species will cease. Systematists will have only to decide (not that this will be easy) whether any form be sufficiently constant and distinct from other forms, to be capable of definition; and if definable, whether the differences be sufficiently important to deserve a specific name. This latter point will become a far more essential consideration than it is at present; for differences, however slight, between any two forms, if not blended by intermediate gradations, are looked at by most naturalists as sufficient to raise both forms to the rank of species. Hereafter we shall be compelled to acknowledge that the only distinction between species and well-marked varieties is, that the latter are known, or believed to be connected at the present day by intermediate gradations whereas species were formerly thus connected. Hence, without rejecting the consideration of the present existence of intermediate gradations between

14 any two forms, we shall be led to weigh more carefully and to value higher the actual amount of difference between them. It is quite possible that forms now generally acknowledged to be merely varieties may hereafter be thought worthy of specific names; and in this case scientific and common language will come into accordance. In short, we shall have to treat species in the same manner as those naturalists treat genera, who admit that genera are merely artificial combinations made for convenience. This may not be a cheering prospect; but we shall at least be freed from the vain search for the undiscovered and undiscoverable essence of the term species. The other and more general departments of natural history will rise greatly in interest. The terms used by naturalists, of affinity, relationship, community of type, paternity, morphology, adaptive characters, rudimentary and aborted organs, &c., will cease to be metaphorical, and will have a plain signification. When we no longer look at an organic being as a savage looks at a ship, as something wholly beyond his comprehension; when we regard every production of nature as one which has had a long history; when we contemplate every complex structure and instinct as the summing up of many contrivances, each useful to the possessor, in the same way as any great mechanical invention is the summing up of the labour, the experience, the reason, and even the blunders of numerous workmen; when we thus view each organic being, how far more interesting- I speak from experience-does the study of natural history become! A grand and almost untrodden held of inquiry will be opened, on the causes and laws of variation, on correlation, on the effects of use and disuse, on the direct action of external conditions, and so forth. The study of domestic productions will rise immensely in value. A new variety raised by man will be a more important and interesting subject for study than one more species added to the infinitude of already recorded species. Our classifications will come to be, as far as they can be so made, genealogies; and will then truly give what may be called the plan of creation. The rules for classifying will no doubt become simpler when we have a definite object in view. We possess no pedigrees or armorial bearings; and we have to discover and trace the many diverging lines of descent in our natural genealogies, by characters of any kind which have long been inherited. Rudimentary organs will speak infallibly with respect to the nature of longlost structures. Species and groups of species which are called aberrant, and which may fancifully be called living fossils, will aid us in forming a picture of the ancient forms of life. Embryology will often reveal to us the structure, in some degree obscured, of the prototypes of each great class.

15 When we can feel assured that all the individuals of the same species, and all the closely allied species of most genera, have within a not very remote period descended from one parent, and have migrated from some one birthplace; and when we better know the many means of migration, then, by the light which geology now throws, and will continue to throw, on former changes of climate and of the level of the land, we shall surely be enabled to trace in an admirable manner the former migrations of the inhabitants of the whole world. Even at present, by comparing the differences between the inhabitants of the sea on the opposite sides of a continent, and the nature of the various inhabitants on that continent in relation to their apparent means of immigration, some light can be thrown on ancient geography. The noble science of Geology loses glory from the extreme imperfection of the record. The crust of the earth with its imbedded remains must not be looked at as a well-filled museum, but as a poor collection made at hazard and at rare intervals. The accumulation of each great fossiliferous formation will be recognised as having depended on an unusual concurrence of favourable circumstances, and the blank intervals between the successive stages as having been of vast duration. But we shah be able to gauge with some security the duration of these intervals by a comparison of the preceding and succeeding organic forms. We must be cautious in attempting to correlate as strictly contemporaneous two formations, which do not include many identical species, by the general succession of the forms of life. As species are produced and exterminated by slowly acting and still existing causes, and not by miraculous acts of creation; and as the most important of all causes of organic change is one which is almost independent of altered and perhaps suddenly altered physical conditions, namely, the mutual relation of organism to organism,-the improvement of one organism entailing the improvement or the extermination of others; it follows, that the amount of organic change in the fossils of consecutive formations probably serves as a fair measure of the relative, though not actual lapse of time. A number of species, however, beeping in a body might remain for a long period unchanged, whilst within the same period several of these species by migrating into new countries and coming into competition with foreign associates, might become modified; so that we must not overrate the accuracy of organic change as a measure of time. In the future I see open fields for far more important researches. Psychology will be securely based on the foundation already well laid by Mr. Herbert Spencer, that of the necessary acquirement of each mental power and capacity by gradation. Much light will be thrown on the origin of man and his history.

16 Authors of the highest eminence seem to be fully satisfied with the view that each species has been independently created. To my mind it accords better with what we know of the laws impressed on matter by the Creator, that the production and extinction of the past and present inhabitants of the world should have been due to secondary causes, like those determining the birth and death of the individual. When I view all beings not as special creations, but as the lineal descendants of some few beings which lived long before the first bed of the Cambrian system was deposited, they seem to me to become ennobled. Judging from the past, we may safely infer that not one living species will transmit its unaltered likeness to a distant futurity. And of the species now living very few will transmit progeny of any kind to a far distant futurity; for the manner in which all organic beings are grouped, shows that the greater number of species in each genus, and all the species in many genera, have left no descendants, but have become utterly extinct. We can so far take a prophetic glance into futurity as to foretell that it will be the common and widely-spread species, belonging to the larger and dominant soups within each class, which will ultimately prevail and procreate new and dominant species. As all the living forms of life are the lineal descendants of those which lived long before the Cambrian epoch, we may feel certain that the ordinary succession by generation has never once been broken, and that no cataclysm has desolated the whole world. Hence we may look with some confidence to a secure future of great length. And as natural selection works solely by and for the good of each being, all corporeal and mental endowments will tend to progress towards perfection. It is interesting to contemplate a tangled bank, clothed with many plants of many kinds, with birds singing on the bushes, with various insects hitting about, and with worms crawling through the damp earth, and to reflect that these elaborately constructed forms, so different from each other, and dependent upon each other in so complex a manner, have all been produced by laws acting around us. These laws, taken in the largest sense, being Growth with Reproduction; Inheritance which is almost implied by reproduction: Variability from the indirect and direct action of the conditions of life, and from use and disuse: a Ratio of Increase so high as to lead to a Struggle for Life, and as a consequence to Natural Selection, entailing Divergence of Character and the Extinction of less-improved forms. Thus, from the war of nature, from famine and death, the most exalted object which we are capable of conceiving, namely, the production of the higher animals, directly follows. There is grandeur in this view of life, with its several powers, having been originally breathed by the Creator into a few forms or into one; and that, whilst this planet has gone cycling on according

17 to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being evolved. JOHN DEWEY MOST PEOPLE, when they look at a spectrum, see a series of distinct colours side by side. When John Dewey looked at a spectrum he saw a continuum-a shading of one colour into another, with no boundaries to indicate precisely where one colour ends and another begins. Mind fades into matter, subject into object, means into ends. The individual merges with the social, liberal education mixes with vocational; science itself is part of a spectrum of things people do, like plowing the earth and sailing ships. There are no eternal essences with fixed outlines. The species move. "Truth" is simply that plastic, growing body of knowledge which serves as a tool in man's struggle to perpetuate his species. No philosopher wasted less time brooding in metaphysical towers than this absent-minded, carelessly dressed pedagogue with the rimless glasses and Vermont drawl. He was active in hundreds of liberal organizations: and causes. His influence on political thought, spelling out the meaning of such terms as "freedom" and "democracy," has been immense. He was never afraid to take partisan positions even when they were unfashionable; for instance, his vigorous condemnation of Stalin's purge trials at a time when most liberals tried to look the other way. Perhaps his greatest influence was in the field of elementary education. The old-fashioned bolted-down desk symbolized for him the old restraints. He wanted to unbolt them. He wanted to unbolt the mind. It could be done, he believed, only by extending the scientific attitude into every phase of human activity. By a pleasant coincidence, John Dewey ( ) was born the same year that The Origin of Species appeared. For Dewey, evolution was the great dissolver of fusty absolutisms, and in the selection chosen here he gives his reasons for thinking so. Originally a lecture delivered in 1909, it has become one of his best known, most influential essays, going to the very heart of his pragmatic philosophy. In later and more technical writings his style was often involved and dull, a fact which led Max Eastman to observe that if Dewey ever wrote a quotable sentence it had become permanently lost in the pile of his 36 books and 815 magazine articles. Perhaps we can recover such a sentence in this essay. "We do not solve them," Dewey concludes, concerning those great, burning questions of history that seem to demand exclusive either or alternatives, "we get over them."

18 JOHN DEWEY The Influence of Darwinism on Philosophy THAT THE publication of the "Origin of Species" marked an epoch in the development of the natural sciences is well known to the layman. That the combination of the very words origin and species embodied an intellectual revolt and introduced a new intellectual temper is easily overlooked by the expert. The conceptions that had reigned in the philosophy of nature and knowledge for two thousand years, the conceptions that had become the familiar furniture of the mind, rested on the assumption of the superiority of the fixed and final; they rested upon treating change and origin as signs of defect and unreality. In laying hands upon the sacred ark of absolute permanency, in treating the forms that had been regarded as types of fixity and perfection as originating and passing away, the "Origin of Species" introduced a mode of thinking that in the end was bound to transform the logic of knowledge, and hence the treatment of morals, politics, and religion. No wonder, then, that the publication of Darwin's book, a half century ago, precipitated a crisis. The true nature of the controversy is easily concealed from us, however, by the theological clamour that attended it. The vivid and popular features of the anti-darwinian row tended to leave the impression that the issue was between science on one side and theology on the other. Such was not the case-the issue lay primarily within science itself, as Darwin himself early recognized. The theological outcry he discounted from the start, hardly noticing it save as it bore upon the "feelings of his female relatives." But for two decades before final publication he contemplated the possibility of being put down by his scientific peers as a fool or as crazy; and he set, as the measure of his success, the degree in which he should affect three men of science: Lyell in geology, Hooker in botany, and Huxley in zoology. Religious considerations lent fervour to the controversy, but they did not provoke it. Intellectually, religious emotions are not creative but conservative. They attach themselves readily to the current view of the world and consecl8te it. They steep and dye intellectual fabrics in the seething vat of emotions; they do not form their warp and woof. There is not, I think, an instance of any large idea about the world being independently generated by religion. Although the ideas that rose up like armed men against Darwinism owed their intensity to religious associations,

19 their origin and meaning are to be sought in science and philosophy, not in religion. Few words in our language foreshorten intellectual history as much as does the word species. The Greeks, in initiating the intellectual life of Europe, were impressed by characteristic traits of the life of plants and animals; so impressed indeed that they made these traits the key to defining nature and to explaining mind and society. And truly, life is so wonderful that a seemingly successful reading of its mystery might well lead men to believe that the key to the secrets of heaven and earth was in their hands. The Greek rendering of this mystery, the Greek formulation of the aim and standard of knowledge, was in the course of time embodied in the word species, and it controlled philosophy for two thousand years. To understand the intellectual face-about expressed in the phrase "Origin of Species" we must, then, understand the long dominant idea against which it is a protest. Consider how men were impressed by the facts of life. Their eyes fed upon certain things slight in bulk, and frail in structure. To every appearance, these perceived things were inert and passive. Suddenly, under certain circumstances, these things-henceforth known as seeds or eggs or germs-- begin to change, to change tepidly in size, form, and qualities. Rapid and extensive changes occur, however, in many things as when wood is touched by fire. But the changes in the living thing are orderly; they are cumulative; they tend constantly in one direction; they do not, like other changes, destroy or consume, or pass fruitless into wandering flux; they realize and fulfil each successive stage, no matter how unlike its predecessor preserves its net effect and also prepares the way for a fuller activity on the part of its successor. In living beings, changes do not happen as they seem to happen elsewhere, any which way; the earlier changes are regulated in view of later results. This progressive organization does not cease till there is achieved a true final term, a, a completed, perfected end. This final form exercises in turn a plenitude of functions, not the least noteworthy of which is production of germs like those from which it took its own origin, germs capable of the same cycle of self-fulfilling activity. But the whole miraculous tale is not yet told. The same drama is enacted to the same destiny in countless myriads of individuals so sundered in time, so severed in space, that they have no opportunity for mutual consultation and no means of interaction. As an old writer quaintly said, "things of the same kind go through the same formalities"-celebrate, as it were, the same ceremonial rites. This formal activity which operates throughout a series of changes and holds them to a single course; which subordinates their aimless flux to its

20 own perfect manifestation; which, leaping the boundaries of space and time, keeps individuals distant in space and remote in time to a uniform type of structure and function: this principle seemed to give insight into the very nature of reality itself. To it Aristotle gave the name,..s. This term the scholastics translated as species. The force of this term was deepened by its application to everything in the universe that observes order in flux and manifests constancy through change. From the casual drift of daily weather, through the uneven recurrence of seasons and unequal return of seed time and harvest, up to the majestic sweep of the heavens-the image of eternity in time --and from this to the unchanging pure and contemplative intelligence beyond nature lies one unbroken fulfilment of ends. Nature as a whole is a progressive realization of purpose strictly comparable to the realization of purpose in any single plant or animal. The conception of species, a fixed from and final cause, was the central principle of knowledge as well as of nature. Upon it rested the logic of science. Change as change is mere dm and lapse; it insults intelligence. Genuinely to know is to grasp a permanent end that realizes itself through changes, holding them thereby within the metes and bounds of fixed truth. Completely to know is to relate all special forms to their one single end and good: pure contemplative intelligence. Since, however, the scene of nature which directly confronts us is in change, nature as directly and practically experienced does not satisfy the conditions of knowledge. Human experience is in flux, and hence the instrumentalities of sense-perception and of inference based upon observation are condemned in advance. Science is compelled to aim at realities lying behind and beyond the processes of nature, and to carry on its search for these realities by means of rational forms transcending ordinary modes of perception and inference. There are, indeed, but two alternative courses. We must either find the appropriate objects and organs of knowledge in the mutual interactions of changing things; or else, to escape the infection of change, we must seek them in some transcendent and supernal region. The human mind, deliberately as it were, exhausted the logic of the changeless, the final, and the transcendent, before it essayed adventure on the pathless wastes of generation and transformation. We dispose all too easily of the efforts of the schoolmen to interpret nature and mind in terms of real essences, hidden forms, and occult faculties, forgetful of the seriousness and dignity of the ideas that lay behind. We dispose of them by laughing at the famous gentleman who accounted for the fact that opium put people to sleep on the ground it had a dormitive faculty. But the doctrine, held in our own day, that

21 knowledge of the plant that yields the poppy consists in referring the peculiarities of an individual to a type, to a universal form, a doctrine so firmly established that any other method of knowing was conceived to be unphilosophical and unscientific, is a survival of precisely the same logic. This identity of conception in the scholastic and anti-darwinian theory may well suggest greater sympathy for what has become unfamiliar as well as greater humility regarding the further unfamiliarity s that history has in store. Darwin was not, of course, the first to question the classic philosophy of nature and of knowledge. The beginnings of the revolution are in the physical science of the sixteenth and seventeenth centuries. When Galileo said: "It is my opinion that the earth is very noble and admirable by reason of so many and so different alterations and generations which are incessantly made therein," he expressed the changed temper that was coming over the world; the transfer of interest from the permanent to the changing. When Descartes said: "The nature of physical things is much more easily conceived when they are beheld coming gradually into existence, than when they are only considered as produced at once in a finished and perfect state," the modern world became self-conscious of the logic that was henceforth to control it, the logic of which Darwin$ "Origin of Species" is the latest scientific achievement. Without the methods of Copernicus, Kepler, Galileo, and their successors in astronomy, physics, and chemistry, Darwin would have been helpless in the organic sciences. But prior to Darwin the impact of the new scientific method upon life, mind, and politics, had been arrested, because between these ideal or moral interests and the inorganic world intervened the kingdom of plants and animals. The gates of the garden of life were barred to the new ideas; and only through this garden was there access to mind and politics. The influence of Darwin upon philosophy resides in his having conquered the phenomena of life for the principle of transition, and thereby freed the new logic for application to mind and morals and life. When he said of species what Galileo had said of the earth, e pur se muove, he emancipated, once for all, genetic and experimental ideas as an organon of asking questions and looking for explanations. The exact bearings upon philosophy of the new logical outlook are, of course, as yet, uncertain and inchoate. We live in the twilight of intellectual transition. One must add the rashness of the prophet to the stubbornness of the partisan to venture a systematic exposition of the influence upon philosophy of the Darwinian method. At best, we can but inquire as to its general bearing-the effect upon mental temper and complexion, upon that body of half-conscious, half- instinctive intellectual aversions and