Though I shall get more kicks than half-pennies, I will, life serving, attempt my work.
-- Darwin
I . "The Bridgewater Treatises"
When Darwin's uncle, Josiah Wedgwood, had sought to obtain the permission of Robert Darwin that Charles might go upon the voyage of the Beagle, he had urged that "the pursuit of Natural History, though certainly not professional is very suitable to a clergyman." [1] This remark is strongly indicative of the esteem in which natural theology was held in early nineteenth century England. Wedgwood was not a biologist. He was simply an affluent, intelligent manufacturer trying to do his nephew a favor. His recourse to this argument is evidence of its strength and wide dissemination in cultivated circles. The traditional observance of life in nature had been part of the legitimate province of the English clergyman since the days of John Ray and Gilbert White. It is significant, therefore, that the devout Fitzroy had chosen to take a "naturalist" on the Beagle rather than a geologist.
The argument for design, that is, the contention that all the multitudinous adjustments of organisms to their environment were evidence of the direct hand of God in earthly affairs, had been vigorously promoted through a long series of theological naturalists from John Ray and William Derham to William Paley. This viewpoint, while naive in its more primitive expression, nevertheless led directly to a great deal of very careful observation of both plants and animals. The microscope in particular enhanced the feeling of wonder toward the works of God and increased human faith in Divine Providence.
This popular attitude is very well expressed in the following passage from Paley's Natural Theology, a book which, though partially derivative, as many such works were after the time of Ray, was very influential in the early part of the century. Paley says: "Nor ought we to feel our situation insecure. In every nature and every portion of nature which we can descry, we find attention bestowed upon even the minutest parts. The hinges in the wings of an earwig and the joints of its antennae, are as highly wrought; as if the creator had had nothing else to finish. We see no signs of diminution of care by multiplicity of objects, or of distraction of thought by variety. We have no reason to fear, therefore, our being forgotten, or overlooked, or neglected." [2]
The italics are my own. They call attention to the way in which the study of natural history was at this time used to sustain Christian faith and comfort the bereaved. There was a general conception of God as a kind of master workman who had personally supervised the creation of even the tiniest organisms of the living world. In earlier centuries the church had largely based its system of theology upon the inspired word of the Scriptures. From about the latter half of the seventeenth century, however, the cultivation of science had led to a more intensive examination of the natural world. A feeling that religious insight could be obtained from the observation of God's works in the things about us led to a great proliferation of works upon natural theology. The telescope and the microscope widened man's comprehension and imagination. The tiniest infusoria, equally with the vast reaches of sidereal space, gave awe-inspiring glimpses of a world whose wonders were proclaimed as the most powerful evidence of God's design. The search for design in nature soon became a mania and everything was made to appear as though created specifically to serve man. There were Bronto (thunder) theologies, Insecto-theologies, Astra-theologies, Phyto-theologies, Ichthyo-theologies, Physico-theologies. Insects and stars alike were seen both figuratively and literally through human spectacles. Man stood at the center of all things and the entire universe had been created for his edification and instruction: hills had been placed for his pleasure, animals ran on four feet because it made them better beasts of burden, and flowers grew for his enjoyment.
This essentially egocentric point of view reached its final if sophisticated expression In the famous Bridgewater Treatises. Francis Henry Egerton, the eighth Earl of Bridgewater, died in 1829 leaving a bequest of eight thousand pounds for a work or works to be written "on the power, wisdom, and goodness of God as manifested in the Creation." Between 1833 and 1836 a series of eight such books were published, through the co-ordinated efforts of Chalmers, Buckland, Whewell, Kirby, and other scholars of the time. [3] They had set out to prove like others before them that the evidence of design In the world about us implies an Intelligent designer. The argument from contrivance had become a standard part of theology. The existence of God, the position of man, the truth of the Bible were all to be "proved" by an examination of the natural world about us. Since evolutionary change went unrecognized and each species of plant or animal was assumed to be a special creation, a particular conscious act on the part of God, natural theology had assumed the impossible burden of demonstrating "the final intention of the Creator in respect to each structure." [4]
The theologian was thus forced into the embarrassing position of having to explain why a benevolent Deity had devised unpleasant parasites with which to torture His subjects. In addition, the static nature of the design argument failed to explain satisfactorily the presence of rudimentary organs. The whole idea had to be propped up by a scaffolding of tendentious theory which rapidly became unwieldy. In the end Darwin was to appropriate the design hypothesis and turn it to quite another purpose. At the time of his voyage, however, it was still the reigning biological doctrine and received pious expression in church and lecture hall alike. Darwin had been a diligent student of Paley's Natural Theology, but what he did to Paley's carefully selected evidences of design will only emerge by degrees as we follow Darwin's thought in the formulation of the Origin.
II. Darwin and Malthus
When Darwin reached home in 1836 he was anxious to dispose of his specimens and set about the reports of the voyage. "I am to have the third volume," he wrote to Fox in 1837, "in which I intend giving a kind of journal of a naturalist.... The habits of animals will occupy a large portion, sketches of the geology, the appearance of the country, and personal details will make the hodgepodge complete. Afterwards I shall write an account of the geology in detail, and draw up some zoological papers." [5] London he characterized as "a vile smoky place." [6] It is obvious that he is already at this time contemplating the' retreat to the country which he later carried out, but he records with pleasure that some papers given before the Geological Society "were favorably received by the great guns, and this gives me much confidence." [7]
His short sojourn in London preceding his marriage had advantages. It brought him a close friendship with Sir Charles Lyell and the opportunity of meeting some of the finest scientific minds of the age. He had scarcely been home eight months before he opened, as he tells us, his first notebook upon the subject of species and began his conversations with commercial breeders. [8] In a letter to Lyell dated September 13, 1838, he wrote as follows: "I have been sadly tempted to be idle -- -that is, as far as pure geology is concerned -- by the delightful number of new views which have been coming in thickly and steadily -- on the classification and affinities and instincts of animals-bearing on the question of species. Note-book after note-book has been filled with facts which begin to group themselves clearly under sub-laws." [9]
This statement is particularly intriguing for two reasons: first, it shows that the interest in animals expressed in South America to his sister Susan was continuing and second, and more important, this letter, written about a month before Darwin read Thomas Malthus in October of 1838, [10] already speaks of "facts" grouping "clearly under sub-laws." What Darwin meant by this cryptic statement it is impossible to say, though one cannot help wondering if he was already groping his way toward the principle of natural selection before he read Malthus on population. Nevertheless, Darwin informs us in his autobiography, when speaking of Malthus, that "being well prepared to appreciate the struggle for existence, which everywhere goes on, from long continued observation of the habits of animals and plants, it at once struck me that under these circumstances favorable variations would tend to be preserved, and unfavorable ones to be destroyed. The result of this would be the formation of new species." [11]
This remark is straightforward enough, but it has always seemed dubious to the present writer that Darwin received his complete inspiration on the selective aspect of the struggle for existence from Malthus, or from his South American observations. The idea is clearly expressed in Paley and even more suggestively in Lyell, both authors whom Darwin had studied with great care. Lyell, for example, notes that "Every species which has spread itself from a small point over a wide area must ... have marked its progress by the diminution or the entire extirpation of some other, and must maintain its ground by a successful struggle against the encroachments of other plants and animals." [12] Again and again Lyell reiterates the observation that "in the universal struggle for existence, the right of the strongest eventually prevails; and the strength and durability of a race depends mainly on its prolificness...." [13]
Actually, as we have already seen, it would appear that Lyell foreran Darwin in the recognition of ecological change brought about by the struggle for existence and pressure of population, but that he did not grasp its creative aspect in terms of limitless organic alteration induced by such means. Darwin's son Francis has himself expressed surprise that his father should have regarded Malthus as providing the necessary clue to natural selection for, as he points out, the Notebook of 1837 contains a discussion which, while a trifle obscure in diction, really expresses the' whole principle. "We can easily see that a variety of the ostrich may not be well adapted, and thus perish out; or on the other hand ... being favorable, many might be produced. This requires the principle that the permanent variations produced by confined breeding and changing circumstances are continued and produced according to the adaptation of such circumstances, and therefore that death of species is a consequence ... of non-adaptation of circumstances." [14]
The statement would be clearer if it read "adaptation to circumstances" instead of "adaptation of circumstances," but anyone acquainted with Darwin's sometimes awkward and hasty wording of ideas in his notebooks will not be inclined to discount this passage. There is, in addition, one other very intriguing notation in the Notebook of 1837: "View of generation being condensation, test of highest organization ..." Francis Darwin inclined to the view that this somewhat cryptic statement means that "each generation is 'condensed' to a small number of the best organized individuals." If this is the case it constitutes additional evidence that Darwin had grasped what was to become the essential principle of his theory before reading Malthus. An added indication lies in the fact that in the same paragraph he refers to adaptation, and while putting in, in parentheses, the Lamarckian explanation, "wish of parents," he places two question marks after the statement. He is apparently beginning to write it off in his mind, but it is one more proof that Lamarck did play a part in his early thinking. [15]
It may well be that Darwin really received only an increased growth of confidence in his previously perceived idea through reading the Malthusian essay. The geometric growth of life as expressed by Malthus greatly impressed him and may have turned his thoughts more intensively upon the struggle for existence. There is evidence in Darwin's essay of 1842 of his impressed reaction to the mathematical approach of Malthus. He comments almost as a memorandum to himself: "Study Malthus and calculate rates of increase [for various species]." [16]
Moreover, Malthus was very popular at this time and therefore a powerful ally. We know that Darwin spoke of him admiringly as a "great philosopher." Perhaps in the vigorous expression of his views Malthus acted as one catalyst in the final precipitation of Darwin's thought. It is at least interesting that both Darwin and Alfred Russel Wallace attribute their insight into the struggle for existence to Malthus, although we know both men had been profound students of Lyell's Principles of Geology. Perhaps it is the mathematical aspect of Malthus which partly explains this situation. It Is picturesque and brief and it captured the imagination as its later widespread use by the Darwinists reveals. [17]
III. The Law of Divergence
As Darwin pondered upon the forces at work in the natural world about him he came to see that over and beyond the pure struggle for life some factor or accessory law must have made for increasing organic diversity. Life, in other words, was a vast ramification of protoplasm into innumerable shapes and forms adapted not alone to differences in climate or medium as, say, air or water, but also it had succeeded in achieving differences of adaptation in a single location. Thus Darwin was later to remark to Asa Gray, "The same spot will support more life if occupied by very diverse forms.... And it follows ... that the varying offspring of each species will try (only a few will succeed) to seize on as many and as diverse places in the economy of nature as possible." [18] Since this Law of Divergence, as it came to be called, was regarded by Darwin as of the utmost significance in evolution, it is not without interest to observe that there are preliminary intuitions of it once more among Darwin's favorite authors.
Humboldt, in describing the tropical forest of South America, does not, of course, state an evolutionary principle, but he sketches exactly the kind of life-situation which was now preoccupying Darwin. "It might be said that the earth, overloaded with plants, does not allow them space enough to unfold themselves. The trunks of the trees are everywhere concealed under a thick carpet of verdure; and if we carefully transplanted the orchidiae, the pipers, and the pothoses ... we should cover a vast extent of ground. By this singular assemblage, the forests, as well as the flanks of the rocks and mountains, enlarge the domains of organic nature." [19]
Paley, however, whom Darwin practically knew by heart, comes very close to a full statement of the law itself except that he does not directly recognize the possibility of evolutionary change save for one cryptic phrase which implies the likelihood of secondary forces at work. This phrase I italicize in the passage that follows. "To this great variety in organized life, the Deity has given, or perhaps there arises out of it, a corresponding variety of animal appetites. For the final cause of this we have not far to seek. Did all animals covet the same element, retreat, or food, it is evident how much fewer could be supplied and accommodated, than what at present live conveniently together, and find a plentiful subsistence." [20]
There is no doubt that this statement contains the germ or the essence, which, given life and motion by Darwin, was destined to become the Law of Divergence. This, in more modern terms, we would call adaptive radiation. Even Paley remarks that "[Superfecundity] allows the proportion between the several species of animals to be differently modified, as different purposes require, or as different situations may afford for them room and food." [21] The passage quoted, equally with some of Lyell's remarks in the Principles, shows a true grasp of dynamic ecological change as the quantity of a given species alters in the struggle for existence.
What is not clearly realized by these earlier writers is the possibility of the slow alteration, not alone of the proportionate numbers of animals and plants in a given environment, but of their actual physical forms ~ well. "The thought of each age," remarked Sir William Thiselton-Dyer on the occasion of the Darwin-Wallace celebration in 1908, "is the foundation of that which follows. Darwin was an admirer of Paley, a member of his own College. He swept in the whole of Paley's teleology, simply dispensing with its supernatural explanation." [22] The manner in which this gigantic reversal of the orthodox field of thought was successfully attempted may now occupy our attention.
IV. The First Essay Attempts
Darwin tells us in his autobiography that directly after his return to England he had set about collecting ·facts which bore in any way on the variation of animals and plants under domestication and nature." [23] He had observed that selection was the key process in the creation of new domestic races of plants or animals, and by steeping himself in the lore of the practical breeder he hoped to discover the secret of change under the conditions of wild nature. He remarks that he spent hours in gin palaces talking to pigeon fanciers or combing the flies of gardeners' magazines. Even after the discovery of Malthus he was not content to relapse into an armchair consideration of the subject but persisted in breeding experiments of his own. particularly upon pigeons. "In your letter," he writes to his friend Joseph Hooker, the botanist, as late as 1849, "you wonder what 'Ornamental Poultry' has to do with Barnacles; but do not flatter yourself that I shall not yet live to finish the Barnacles, and then make a fool of myself on the subject of species, under which head Ornamental Poultry are very interesting...." [24]
Darwin nowhere states just what led him to feel that domesticated forms might have some relationship to the secret he sought, but we know that the selective breeding of cattle and sheep was widely practiced toward the end of the eighteenth century. Many of the modern breeds became established at this time. [25] Moreover, there was great interest among naturalists as to the causes of variation in living things. [26] The examination of the products of colonial America and the passion for classification which, guided and stimulated by Linnaeus, had made the latter a world figure, doubtless played a considerable role in the development of this interest on the part of the public. At any rate, it was in such an atmosphere that Darwin was immersed in his youth. We know, in addition, that he observed and speculated upon a peculiar breed of cattle he encountered on the pampas. From the self-conscious awareness of the eighteenth- and early nineteenth-century naturalists that man had successfully altered living things, Darwin, convinced already of the reality of evolution, must have passed rapidly to the suspicion that the effects of small, controlled variations might in reality be potentially endless. Finally, and perhaps most important of all for Darwin, the road had been pointed out by no less a man than Sir Charles Lyell himself, who had said in the Principles: "The best authenticated examples of the extent to which species can be made to vary may be looked for in the history of domesticated animals and cultivated plants." [27] By the time of his essay of 1844 Darwin is willing to write: "That a limit to variation does exist in nature is assumed by most authors, though I am unable to discover a single fact on which this belief is grounded." [28]
This is a bolder expression of Darwin's views than he was willing to express even two years earlier. Since we possess two compositions which may be regarded as trial runs before the Origin, and which were not published in Darwin's lifetime, their careful examination may be expected to yield us information as to the progress of his thought. We owe their preservation and publication in 1909 to Darwin's eldest son, Francis. There are two of these essays, one written in 1842, the other in 1844. The trial attempt of 1842 was not known to be in existence until it was discovered hidden in a cupboard when the old house at Down was vacated by the family in 1896. Though roughly and rapidly composed for his own purposes and not for publication, the first essay, seventeen years before the appearance of the Origin, contains the essential essence of Darwin's developed thought. As Huxley wrote long afterwards: "The facts of variability, of the struggle for existence, of adaptation to conditions were notorious enough; but none of us had suspected that the road to the heart of the species problem lay through them, until Darwin and Wallace dispelled the darkness." [29] In the first essay of 1842 all of these factors dwelt upon by Huxley are clearly assigned the roles they will later play in the Origin of Species.
The essay begins with a discussion of variation under domestication and this approach persists through the essay of 1844 and reappears as the opening chapter of the Origin itself. One might say that there is simply a steady enlargement in scope, sweep of ideas, and precision of statement from the first essay to the completion of the Origin. As one studies these early essays, however, one cannot help observing the transitional nature of much of Darwin's thought-transitional, that is, in the sense of passing from outright Lamarckian inheritance toward the as yet unformulated genetics of the future.
Although Darwin was in the habit of repudiating violently any intimation that he had pro.6ted from Lamarck, we have already seen that he was acquainted at an early age with English versions of the latter's work and in 1845 there is a reference in an unpublished letter to Lyell [30] regarding "my volumes of Lamarck." His rather cavalier rejection of his distinguished forerunner is tinged with an acerbity whose cause at this late date is difficult to discover, Darwin, although he added a meager and needlessly obscure historical introduction to later editions of the Origin, was essentially indifferent to his precursors, and doubtless resented Owen's sharply critical treatment of this fact in the latter's review of the first edition of the Origin. [31]
As we examine the early essays, however, it becomes apparent that Darwin's theory does not lack Lamarckian elements in spite of the removal of the idea of willed organic change. Darwin always maintained, and rightly, that he could not see how climate (Buffon) or the individual effort of the animal (Lamarck) could accomplish such peculiar organic adaptations as, for example, that of a woodpecker. Instead, Darwin introduced the principle of fortuitous variation but he retained the idea that environment, climate, domestication, or other similar exterior influences were a stimulating factor which might induce the variations which were then selected in the struggle for existence." Moreover, he held to the Lamarckian conception of the genetic transmissal of characteristics acquired by the animal during its own lifetime. This fact, though somewhat muted in the first edition of the Origin, re-emerged more powerfully in later editions as the Darwinian position became difficult to sustain under the assault of the mathematicians and the physicists, which will be discussed later on in Chapter IX. A few remarks will serve to indicate Darwin's thinking upon these topics.
As early as the Journal of Researches (1839) and drawn from material which, judging from clues in the Diary of the Voyage, dates to late in 1833, Darwin remarks that "Nature by making habit omnipotent and its effects hereditary, has fitted the Fuegian for the climate and productions of his country" (p. 237). This statement is so strongly Lamarckian that it suggests again the young Darwin's intellectual antecedents during the earlier portion of his voyage. On the very first page of the essay of 1842 he mentions that "habits of life develope certain parts.... Most of these slight variations tend to become hereditary." [33] He expresses, in addition, the view that "when the organism is bred for several generations under new or varying conditions, the variation is greater in amount and endless in kind." He is then careful to maintain that variation is not the product of direct effect from external conditions but only as these influence the reproductive powers and thus induce mutative changes.
In the essay of 1844 essentially the same views are given though in a more clearly expressed and qualified fashion. Also we observe here a theoretic trend which was to give an opening to Darwin's opposition and later to bring advice and counsel from his friendly rival Wallace. I refer to Darwin's failure, in spite of his Galapagos' experience, to estimate properly the amount of individual variation existing in wild nature. Two things were apparently responsible for his conservatism on this point: first, his own innately cautious reluctance to advocate what he could not thoroughly document or see; second, his preoccupation with domesticated plants or animals whose variation was easily observable and superficially so much more evident than that of creatures existing in a state of nature.
As a result, Darwin came to associate marked variation with the domestic state and to comment that "the amount of variation [was1exceedingly small ... in a state of nature, and probably quite wanting ... in the majority of cases...." [34] Domestication with its accompanying tendency to vary seemed, he thought, "to resolve itself into a change from the natural conditions of the species." If this, then, promoted a tendency to vary, "organisms in a state of nature must occasionally in the course of ages be ex posed to analogous influences." These "influences" he ascribed to climatic and other inexplicable causes of an external character which, along with geographical isolation, would promote evolutionary development.
It is evident from these observations that Darwin's search for the mechanism of change in wild nature had led him to seek for environmental rather than interior causes of change. His considerable belief that change in nature was to a degree the "occasional" product of accidental migration or climatic alteration led him directly to a need for enormous quantities of time for the development of the living world. In this reluctance to accept an internal mutative factor and in his preference for postulated changes occurring only in lengthy, sporadic intervals as the external world might dictate, Darwin was unconsciously placing a heavy load on the credibility of his doctrine of fortuitous improvement through natural selection. Though by the time the Origin was written Darwin placed considerable emphasis on variability in wild nature and never again was so pessimistic on this point as in the second chapter of the essay of 1844, a residue of this philosophy did not escape his critics. He still argued that under nature organisms varied in less degree and he contented himself with the rhetorical observation that since useful variations have been accumulated under domestication, others "useful in some way to each being in the ... complex battle of life should sometimes occur in the course of thousands of generations." This statement, whose pertinent portion I have italicized, reveals the timidity and caution with which Darwin approached the subject of variation under natural conditions. Obviously it opened the way for critics to point out that if advantageous variation was this rare, all of the many intricate organs, habits, and behavior manifested in the past and living worlds would have demanded fantastic lengths of time for their appearance and dissemination. Moreover, such a slow production of variations would be further retarded by the likelihood that they would not appear at a favorable moment in the life of the species.
Wallace, bolder by nature and perceiving the danger implicit in this hesitant line of reasoning, wrote to Darwin in July of 1866 urging him to abandon the sort of statements we have quoted above as tilting the scales too strongly against himself. Wallace pleads at some length: "Such expressions have given your opponents the advantage of assuming that favorable variations are rare accidents, or may even for long periods never occur at all and thus [the] argument would appear to many to have great force. I think it would be better to do away with all such qualifying expressions, and constantly maintain (what I certainly believe to be the fact) that variations of every kind are always occurring in every part of every species, and therefore that favorable variations are always ready when wanted. You have, I am sure, abundant materials to prove this, and it is, I believe, the grand fact that renders modification and adaptation to conditions almost always possible. I would put the burthen of proof on my opponents to show that anyone organ, structure or faculty, does not vary, even during one generation, among all the individuals of a species; and also to show any mode or way, in which any such organ, etc. does not vary." [35] In making this statement Wallace showed less addiction to the echoes of Lamarckian thought than his master. He was moving toward a more modem point of view. It is worth noting that Darwin took his advice. In later editions the sentence in Chapter V of the Origin which originally spoke of favorable mutations occurring "in the course of thousands of generations" has been unobtrusively altered to "successive generations."
Curiously enough, some years after Darwin's death, Hooker writing to Huxley expressed the view that "Darwin has nowhere that I can think of dealt with the causes of variation ... and I doubt his assenting to the view that they were in any scientific sense limited or directed by external conditions...." [36]
This statement has been rather widely and popularly accepted, yet Darwin himself wrote to Hooker in 1862 saying, "You speak of an inherent tendency to vary wholly independent of 'physical conditions'! This is a very simple way of putting the case ... but two great classes of facts make me think that all variability is due to change in the conditions of life: finally, that there is more variability and more monstrosities ... under unnatural domestic conditions than under nature; and, secondly, that changed conditions affect in an especial manner the reproductive organs." [37]
As the years went on Darwin wavered on certain points, altered sentences, blew hot and cold in letters to friends, including Hooker and Huxley, but there is no evidence he totally abandoned the beliefs we have outlined, He besieged Gray upon the variability manifested by newly naturalized plants and, in at least one instance, expressed surprise that such plants should not have proved variable. Nevertheless, he clung to his own point of view. As his surviving friends entered the autumn of their careers they seem to have been loath to remember before a later, critical generation this fading argument of the master. So much had been written, and the subject, even in Darwin's hands, had proved so elusive that it was left to die a natural death. But the widely held notion that Darwin totally abandoned it is false. It is true he hesitated, that much at least can be allowed. Far more than his younger colleague Wallace, however, or the brisk and aggressive Huxley, he never totally escaped the shadow of Lamarck, the man who had haunted him at Edinburgh and in Lyell's pages read on the Beagle long ago.
V. Darwin and Design
Although Lamarck had been dismissed as a "French atheist" in England and his work maligned in the conservative English reaction to the French Revolution and its Napoleonic consequences, there is no essential difference in the publicly expressed theological outlook of either Darwin or Lamarck. Both acknowledge a Creator, a Divine Author of all things, but both contend that the appearance of life on the planet, and its subsequent enormous radiation into divergent forms, is the product of secondary law as unswerving as that which the astronomer reads in the heavens. God, in other words, has not personally superintended the "emergence of every species of gnat, mole, and cricket. Instead, these have come about through the working out of the natural forces implanted in that highly complicated chemical compound known as protoplasm, and the response of this same protoplasm to the environmental world about it. "It is derogatory," says Darwin in the first essay of 1842, "that the Creator of countless systems of worlds should have created each of the myriads of creeping parasites and slimy worms which have swarmed each day of life ... on this one globe." [38] The creation and extinction of forms, he goes on to contend instead, "is the effect of secondary means." On homological resemblances alone, he argued later, "I disbelieve in ... innumerable acts of creation." [39] Species formation, he wrote to Lyell, "has hitherto been viewed as beyond law, in fact this branch of science is still with most people under its theological phase of development." [40] "For the life of me," Darwin maintained, "I cannot see any difficulty in natural selection producing the most exquisite structure, if such structure can be arrived at by gradation, and I know from experience how hard it is to name any structure towards which at least some gradations are not known." [41]
As one studies these remarks, and many like them, one can observe that the continuity in nature which had been maintained by Sir Charles Lyell against the catastrophists in geology has now been extended to the living world. The stability of natural law, first glimpsed in the heavens, had been by slow degrees extended to the work of waves and winds that shape the continents. Finally, through the long cycles of erosion and the uneasy stirring of the ocean beds, it was beginning dimly to be seen that life itself had passed like a shifting and ephemeral apparition across the face of nature. Nor could that elusive phantom be divorced from man himself, "the great subject," as even Darwin once remarked. If fin and wing and hoof led backward toward some ancient union in the vertebrate line, then the hand of man and ape could be scanned in the same light. Even had they wished, the scientists could not stop short at the human boundary. A world, a dream world which had sustained human hearts for many centuries, was about to pass away. It was the world of design.
"Now it appears," wrote one wistful philosopher, "that Darwin has at last enabled the extreme materialist to attempt and carry the design argument, the last and hitherto impregnable fortress behind which natural theology has entrenched herself." [42] President Barnard of Columbia University declared in 1873 that if organic evolution were true then the existence of God was impossible. "If," he declared bitterly, "the final outcome of all the boasted discoveries of modern science is to disclose to men that they are more evanescent than the shadow of the swallow's wing upon the lake ... give me then, I pray, no more science. I will live on in my simple ignorance, as my fathers did before me...." [43] Time and time again similar, if not more outraged, expressions echoed in intellectual quarters both in America and Europe. Man bad first gazed out upon the night skies and found himself and his planet dwarfed by the immensities of time and space; now, to his fear and chagrin, he was learning that his ancestry was that of an arboreal primate who in the long course of Tertiary time had descended to the ground and achieved some dexterity in the manipulation of stones. The wonder of the human achievement was lost for a moment in the sick revulsion of the wounded human ego. The fallen Adam had stared into the mirror of nature and perceived there only the mocking visage of an ape. Frederick Engels looking on amusedly at the disintegration of the philosophy of the Bridgewater Treatises commented: "Until Darwin, what was stressed by his present adherents was precisely the harmonious co-operative working of organic nature, how the plant kingdom supplies animals with nourishment and oxygen, and animals supply plants with manure, ammonia, and carbonic acid. Hardly was Darwin recognized before these same people saw everywhere nothing but struggle." [44] Papers poured from the press denouncing and refuting the Origin but the time for that was long past. Its mass of accumulated evidence had the weight of a boulder. Criticism flowed around and over it but the boulder in all its impenetrable strength remained.
Philosophically Darwin had achieved several things. Whether every aspect of his interpretation of the evolutionary process was to prove correct or not -- and about this he retained more fundamental doubts than his followers -- his work had destroyed the man-centered romantic evolutionism of the progressionists. It had, in fact, left man only one of innumerable creatures evolving through the play of secondary forces and it had divested him of his mythological and supernatural trappings. The whole tradition of the parson-naturalists had been overthrown. Mechanical cause had replaced Paley's watch and watchmaker. It was not possible to argue from special design to the Deity. If this were true it could also be observed that men no longer were forced to wonder privately by what road the parasitism and disease which had troubled Darwin had come to exist in the world. These, too, were part of the evolving life-web, but they did not represent preordained evil. Man could learn from the secondary laws which had brought them into being how they might be controlled.
The key change in the intellectual climate of the nineteenth century came with the recognition of adaptation, of the fact that creatures fit themselves to their environment. Lamarck and a few others had glimpsed this fact but most naturalists had gone on examining their universe blinded by a tradition of natural theology based on special creation. With Darwin we come to observe a very different world -- a world with which he is already toying in the first essay of 1842; he is concerned with abortive organs as Lamarck was before him -- rudiments, echoes from the past, traces of vanished limbs, soldered wing cases, buried teeth -- all that conglomeration of useless organs that lie hidden in living bodies like the refuse in a hundred-year-old attic. "No one can reflect on this without astonishment," muses Darwin; "can anything be clearer than that wings are to fly and teeth to bite and yet we find these organs ... in situations where they cannot possibly be of their normal use." [45]
The only reasonable explanation of this fact, which even Cuvier could not satisfactorily explain, lies in the evolutionary past of every species of organism-the ghostly world of time in which animals are forever slipping from one environment to another and changing their forms and features as they go. But the marks of the passage linger, and so we come down to the present bearing the traces of all the curious tables at which our forerunners have sat and played the game of life. Our world, in short, is a marred world, an imperfect world, a never totally adjusted world, for the simple reason that it is not static. The games are still in progress and all of us, in the words of Sir Arthur Keith, bear the wounds of evolution. Our backs hurt, we have muscles which no longer move, we have hair that is not functional. All of this bespeaks another world, another game played far behind us in the past. We are indeed the products of "descent with modification."
Yet as we dip more deeply into the pages of the Origin and as we browse in that great body of commentary which grew up around it one thing becomes apparent: Darwin did not destroy the argument from design. He destroyed only the watchmaker and the watch. "Under my hearty congratulations of Darwin for his striking contributions to teleology," wrote Asa Gray to de Candolle in 1863, "there is a vein of petite malice, from my knowing well that he rejects the idea of design, while all the while he is bringing out the neatest illustrations of it." [46] Alone among Darwin's immediate associates Gray inclined toward a more theistic position. We need not pursue his line of thinking here except to note that he sensed very early the fact that only a certain type of design argument had been eliminated by Darwin, namely, the finalistic one. Design by special creation implies the creation of an animal or plant for a special purpose and for all time; it is, in other words, final design. That was the design of the early naturalists whose last echoes resound in Paley and the Bridgewater Treatises. The word "final," however, throws a tremendous burden upon the theologian. "It places him," to reiterate the remarks of Lewis Hicks, "in the attitude of attempting to demonstrate, not merely a purpose but the purpose, the only, the ultimate, the exclusive, the final intention of the Creator in respect to each structure." [47] Obviously, in the light of the discovery that organisms change their bodies and the functions of their organs, Hicks's stricture becomes most pertinent. The design enthusiasts had assumed to define the intentions of the watchmaker only to discover that he had no final purpose which they could anticipate and that the watch, furthermore, was showing signs of turning into a compass through some self-directed reorganization of its inner structure.
The analogy is plain. The evolutionists discovered that nature "makes things make themselves" and thus succeeded in apparently removing the need of a Master Craftsman. The resulting excitement was so great that it was only later that the question began to be asked: Why does nature let things make themselves? Obviously this is a question science can only philosophize about but cannot answer. It can trace the organism down to the final cell; it may even be able someday, In its knowledge of biophysics and chemistry, to create simple life, but it will still not be able to answer the final why. For at that point science will have left the field of secondary causes in which it operates so successfully and, Instead, will be asking the primary and unanswerable questions.
Darwin had delivered a death blow to a simple, a naively simple, form of the design argument but, as Huxley himself came to realize, it is still possible to argue for directivity In the process of life even though that directivity may be without finality in a human sense. The rise of a broad and more sophisticated teleology may well have played a part in the development of the organismic philosophies of later years. Cuvier's grasp of the body as a functioning whole was far greater than Darwin's. Cuvier was struck with the wonderful stability of the functioning organism; Darwin with a theory of change. In pursuit of the mechanism of that change he tended to forget or ignore the interior organizing ability of the body, the curious adjustments of which it is capable and which he passed over lightly with the word "correlations" and references to "complex laws." Not even today is it possible to describe satisfactorily what power controls the innumerable activities, not alone of a living body, but of just one functioning cell which has to assemble and activate within itself all the chemical components necessary for its existence.
The concern with exterior struggle which followed the publication of the Origin of Species diverted biologists for decades from the most mysterious aspect of the living organism -- how its elaborate interior system is so subtly controlled and regulated. Cuvier differed from Darwin in his concern with the great organ systems underlying classes and phyla. As a comparative morphologist he was occupied with divergent, stable systems; Darwin, as we have seen, with adaptability and change. Both were men of great insight and if they could have been combined into one person, much later confusion might have been avoided. Human lives are limited in time, however, and a powerful mind, by its own interests, draws its particular followers down a diverging path for years. It was true of Cuvier who ignored Lamarck and it was true in a more subtle way of Darwin who ignored the organismic aspect of the thought of Cuvier.
VI. Darwin and Lamarck
To conclude our philosophic discussion of the making of the Origin a short comparison of the major tenets of the Darwinian as opposed to the Lamarckian view of nature will prove useful. It should be emphasized that we are here examining the writings of Darwin and Lamarck, not the embellishments or alterations made upon their systems by later writers. It must also be remembered In fairness to Lamarck that he was writing a half century earlier than Darwin, and with far less accumulated knowledge at his command.
Both (and in this respect Lamarck was far ahead of most of his generation) recognized that vast intervals of time were involved in the process of organic change. Each visualized the process as continuous, not saltatory. Each saw clearly that it was the exceedingly slow tempo of evolution as contrasted with the development of the individual which gave the illusion of total organic stability. Both saw life as branching and ramifying into a diversity of habitats and becoming by degrees ecologically adapted.
Here, however, a difference can be observed which reflects Lamarck's closer association with the thought of the eighteenth century. It is, he maintains, the necessity of ecological adjustment, of adaptation, which interferes with the perfectly graduated scale of nature which would otherwise come about naturally by means of an inner perfecting principle within the organism. It is the environment, in other words, which, in concert with the modifying power within the living creature, induces modifications of animal structure. There is thus an ideal structure toward which the organism would evolve, but which is constantly reworked by the creature's efforts to maintain and adjust itself to the world around it. This adjustment achieved by need, by the effort of the individual, will remain static and unchanging so long as the environment remains unchanged. In spite of Darwin's rejection of Lamarck's inner perfecting principle and modification by need to the demands of the habitat, one can observe that his break with Lamarck is not complete. The struggle for existence, the willingness of the organism to struggle, a fact which Darwin does not attempt to explain, equates at least partially, though perhaps not quite so teleologically, with Lamarck's life-power, or perfecting principle.
Furthermore, as we have previously had occasion to note, the Darwin of the essay of 1844, and similarly in a somewhat modulated tone thereafter, underestimates variation in wild nature. He comes close to assuming Lamarck's view of the perpetual stability of a once adapted form. Something in the external environment, they both believe, must impinge upon the organism to cause further change. Where Lamarck would have demanded renewed interior need for adjustment as a modifying force, Darwin institutes an environmental change which produces germ cell modifications by influence from without. These new characters are then selected as the creature struggles for life in its new or altered environment. It is a reworked Lamarckism but the similarities are intriguing. Of course, the belief in the reality of acquired characteristics was shared by both men. In Darwin's case, for reasons to be explored in a later chapter, this type of inheritance was to be carried to great lengths in his later work.
We have previously noted that the concept of the struggle for existence has sometimes been described erroneously as one of Darwin's contributions to general biological theory. By his own words be drew upon Malthus's treatment of human population problems and applied this concept throughout the organic world. Here again it should be remembered that knowledge of the struggle for existence in nature is to be found in Lamarck, Paley, and Lyell. By the early nineteenth century it was a commonplace.
But to Lamarck the "war of nature" was a pruning device, holding life in order and restraining the limitless fecundity of nature. It was not needed in order to achieve the transformation of species, since for him another mechanism was available. As a consequence, Lamarck ignored its possible winnowing effect in the preservation of variation. Darwin, by contrast, recognized its possible role in the accumulation of favorable mutations -- even if the latter emerged in a purely fortuitous fashion. We come here to an exceedingly interesting and neglected point: What led Darwin to believe in the chance emergence of new characters? This constitutes his major break with Lamarck and it is far more important than his recognition of the struggle for existence. The latter takes on renewed importance only after one believes that chance variations emerge and are inherited. After this is recognized, and only then, does the commonplace and widely recognized "struggle" become a genuine creative device.
Darwin at no point dates for us the time when this distinction emerged clearly In his mind, but one may suspect that the analysis of the Galapagos fauna with its variable products in isles not widely separated and climatically similar played its part. Here, "need," in the Lamarckian sense, should have produced similar results, but if one retained the idea that a new environment merely stimulated fortuitous variation which was than selected by struggle -- one would be moving toward a new interpretation of evolution by way of Lamarck. This apparently is what Darwin did. Similarly the domestic breeding in which Darwin also took such deep Interest offers examples of the development of odd, exotic, and quite useless or even detrimental characters preserved by artificial selection. These could hardly be regarded as teleologically implanted in the organism and Darwin uses this fact as an argument against the predetermination of animal form. Yet to promote the variation he has recourse again to the argument that domestication in some manner stimulates variability.
It is impossible, as one considers this subject in the context of Lamarck's thought, not to wonder why Darwin had to seek his inspiration in Malthus, or why in writing to Lyell long afterward he found it necessary to characterize Lamarck's as a "wretched book ... from which (I well remember my surprise) I gained nothing." The surprise, one comes to feel, should not be Darwin's. Rather it should be the surprise of the historian who finds that the two men shared similar views on the significance of domestic breeding, even to the extent of similar observations upon pigeons, greyhounds, and bulldogs, upon the interpretation of rudimentary parts, even upon use and disuse and their effects upon individual organs. They shared also like views upon man's relationship to the primates, except that Darwin was in a position to see more clearly man's paleontological relationship to extinct anthropoids. They felt varieties and species to be shifting, nebulous, and ill-defined. Though Lamarck hesitated over the question of total extinctions, he shared with Darwin a belief that morphological similarities indicated continuity of descent. It may be said justly that they differed in their opinions upon spontaneous generation, which Lamarck favored, and that Darwin eschewed necessary progression. Yet Darwin on the final page of the Origin so far forgot his antipathy to the idea as to write: "All corporeal and mental endowments will tend to progress toward perfection." In this he could no more quite escape his antecedents than Lamarck could escape the Scale of Nature.
Lamarck, however, in his final pages offers a sage observation. He says: "It is not enough to discover and prove a useful truth ... but that it is necessary also to be able to propagate it and get it recognized." For this effort Lamarck, as we have seen, was too old, too inept, too poor; too ahead of his time. Darwin is often pictured as similarly launching his frail bark upon the restless intellectual currents of his day. There is one difference. He had acquired Lamarck's bitterly learned wisdom by way of the worldly-wise geologist Lyell. His book was not launched alone.
Edmund Gosse in his autobiographical study, Father and Son, throws an unconscious light upon the way in which that great book, the Origin, entered the world. "It was the notion of Lyell, himself a great mover of men, that before the doctrine of natural selection was given to a world which would be sure to lift up at it a howl of execration, a certain bodyguard of sound and experienced naturalists, expert in the description of species, should be privately made aware of its tenor. Among those who were thus initiated or approached with a view toward possible illumination, was my Father. He was spoken to by Hooker, and later on by Darwin ... in the summer of 1857." [48] The great idea was being launched again, as Lamarck had foreseen. One wishes that Darwin and Huxley, both of whom had decried the shouldering and pushing for eminence among the scientists of their day, might have been just a little kinder to that old man whose bones are lost among the forgotten millions of the Paris poor. In the end perhaps it does not matter, but it is ironic that he who glimpsed so much truth should largely be remembered as the perpetrator of an error which was also shared by his intellectual descendant, Charles Darwin -- the belief in the inheritance of acquired characteristics.
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Notes:
1. LLD, Vol. 1, p. 198.
2. William Paley, Natural Theology, London edition of 1836, Vol. 2, p. 201.
3. E. C. Massner, Bishop Butler and the Age of Reason, Macmillan, New York, 1936, p. 203. See also D. W. Gundry, "The Bridgewater Treatises and Their Authors," History, 1946, Vol. 31, pp. 140-52, and George Ensor, Natural Theology: the Arguments Of Paley, Brougham, and the Bridgewater Treatises on this Examined, London, 1836.
4. L. E. Hicks, A Critique of Design Arguments, New York, 1883, p. 42.
5. LLD, Vol. 1, pp. 279-80.
6. Ibid., p. 282.
7. Ibid., p. 280.
8. A few excerpts were given by Francis Darwin in Vol. 2 of the LLD.
9. LLD, Vol. 1, p. 298.
10. Ibid., p. 83.
11. LLD, Vol. I, p. 83.
12. PG, Vol. 3, p. 67.
13. Ibid., Vol. 2, p. 391. For a more extended treatment of my views on Sir Charles Lyell see "Charles Lyell" Scientific American, 1959, Vol. 201, pp. 98-101.
14. FO, p. xvi. An entry in the Beagle diary (p. 212) speaks of the cause of Fuegian warfare as involving the means of subsistence. This statement (1834) shows very early Darwinian concentration upon the struggle for existence.
15. LLD, Vol. 2, p. 8. The recent publication in full of Darwin's Notebook by Sir Gavin de Beer makes Darwin's interest in Lamarck even more apparent.
16. FO, p. 8.
17. In addition it should perhaps not pass unnoted, as a speculative point, that to have referred to Lyell as a direct source of inspiration would have been, for both Darwin and Wallace, to quote a man publicly opposed to transmutation in support of that doctrine. Malthus, by contrast, was active In a totally different field, and had a popular following. Since he was the source of most of nineteenth-century England's thinking on the struggle for existence, nothing was more natural than to have recourse to him as the "authority," even if one had largely digested his ideas by way of Intermediate sources.
18. LLD, Vol. 2, pp. 124-25.
19. A. von Humboldt, Personal Narrative of Travels, 3 vols., Bohn, ed., London, 1852, Vol. 1, p. 216. (Italics mine. L.E.)
20. W. Paley, Natural Theology, London ed. of 1822, p. 229. Huxley, in fact, speaks of Paley in his recognition of secondary causes as "proleptically" accepting the hypothesis of evolution. LLD, Vol. 2, p. 202.
21. Ibid., p. 317.
22. The Darwin-Wallace Celebration Held on Thursday, July 1, 1908, by the Linnean Society of London, London, 1908, p. 37.
23. LLD, Vol. 1, pp. 82-83.
24. Ibid., p. 376.
25. C. F. A. Pantin, "Darwin's Theory and the Causes of its Acceptance," The School Science Review, June, 1951.
26. J. C. Ewart, "The Experimental Study of Variation," Report of the British Association for the Advancement of Science, Glasgow, 1901, p. 666.
27. PG, Vol. 2, p. 354.
28. FO, p. 109. (Italics mine. L.E.)
29. LLD, Vol. 2, p. 197.
30. In the possession of the American Philosophical Society, Philadelphia, Pennsylvania.
31. Richard Owen, "Darwin on the Origin of Species," Edinburgh Review, 1860, Vol. 3, pp. 487-532.
32. In 1856 he stated explicitly to Hooker: "My conclusion is that external conditions do extremely little, except in causing mere variability." LLD, Vol. 2, p. 87. In this remark he parallels the belief of Maupertuis.
33. FO, p. 1.
34. Ibid., p. 83.
35. James Marchant, Alfred Russel Wallace: Letters and Reminiscences, New York, 1916, pp. 142-43.
36. Life and Letters of Sir Joseph Hooker, Vol. 2, p. 304.
37. MLD, Vol. 1, p. 198.
38. FO. p. 51.
39. MLD, Vol. 1, p. 173.
40. Ibid., p. 194.
41. LLD, Vol. 2, pp. 303-4.
42. William Graham, The Creed of Science, London, 1881, p. 319.
43. Sidney Ratner, "Evolution and the Rise of the Scientific Spirit In America," Philosophy of Science, 1936, Vol. 3. p. 115.
44. R. L. Meek, Marx and Engels on Malthus, Lawrence and Wishart, London, 1953. p. 186.
45. FO, p. 45.
46. Jane Gray, Letters of Asa Gray, Boston, 1894, Vol. 2, p. 498.
47. L. E. Hicks. A Critique of Design Arguments, New York, 1883. p. 42.
48. Wm. Heinemann, Windmill Library ed., London, 1928, p. 106. Gosse's memory seems slightly at fault here. The date was most probably the summer of 1858.