the rise and fall of darwin's second theory - … and fall of...the rise and fall of darwin’s...

The Rise and Fall of Darwin’s Second Theory

GEORGE JAMES GRINNELL

History Department M&faster University Hamilton, Ontario L8S 4L9, Canada

DARWIN’S EVALUATION OF LAMARCK

Reaction in Public

In an 1844 letter to J. D. Hooker, Charles Darwin writes, “Heaven forfend me from Lamarck[s] nonsense of a ‘tendency to progression,’ ‘adaptations from the slow willing of animals,’ etc.!” Later in the same letter he continues, “With respect to books on this subject [evolution] , I do not know any systematical ones, except Lamar&s, which is veritable rubbish.” l

Writing again to Hooker in 1849, Darwin further criticizes Lamarck: “Lamarck is the only exception, that I can think of, of an accurate describer of species at least in the Invertebrate Kingdom, who has disbelieved in permanent species, but he in his absurd though clever work has done the subject harm.“’

In an 1859 letter to T. H. Huxley, Darwin insinuates that Lamarck may have taken his ideas of transformation from Erasmus Darwin without giving proper credit.3 Of all the references to Lamarck in the letters of Charles Darwin, none speaks favorably of him or of his work. Darwin was primarily concerned with disassociating himself from Lamarckianism, an endeavor in which he was never totally suc- cessful. Such words as “nonsense,” “absurd,” and “rubbish” Darwin felt to be the best descriptions of Lamar&s philosophy.

In a letter to Asa Gray in 1860, Darwin deplores the fact that a reviewer, W. Hopkins, has lumped Darwinian evolution with La- mar&an transformism. “He does not in the least appreciate the dif- ference in my views and Lamarck’s.“4

1. Francis Darwin, ed., More Letters of Charles Darwin (New York: D. Appleton, 1903), I, 41,43.

2. Francis Darwin, ed., Charles Darwin’s Autobiography with his Notes and Letters Depicting the Growth of the Origin of Species (New York: Collier Books, 1961), pp. 139,140;letter to J. D. Hooker, September 1849.

3. F. Darwin, More Letters, I, 125. 4. Ibid., I, 153.

Journal of the History ofBiology, vol. 18, no. 1 (Spring 1985), pp. 51-70. 0022-5010/85.10 0 1985 by D. Reidel Publishing Company.


Nor did Darwin’s views mellow with age. In an 1863 letter to Charles Lyell, Darwin expresses anger at Lyell’s assertion that the Origin of Species was only a modification of Lamarck’s views. Darwin recognizes that Lamarck had preceded him in the idea that species evolve, but he points out that Plato, Buffon, his grandfather Erasmus, and many others had held similar views. “I can see nothing else in common between the ‘Origin’ and Lamarck,” he avers. Later in the same letter he says that he considers Lamar&s Philosophie zoologique “a wretched book, and one from which (I well remember my surprise) I gained nothing.“5

In his more formal publications Darwin is less vehement in his condemnation of Lamarck, yet in his Journal of researches into the natural history and geology of the countries visited during the voyage of the Beagle around the world, his sole reference to Lamarck concerns the blindness of the tucutuco: “Lamarck would have been delighted with this fact had he known it, when speculating (probably with more truth than usual with him) on the gradually acquired blindness of the As~alax.“~ Apparently the informality of the Journal gave sufficient license to drop this snide comment about Lamar&s work, but in his scientific publications Darwin restrains himself. Instead of making derogatory remarks, he avoids commenting at all. In the On&in of Species, Lamarck is mentioned once, a relatively trivial point about analogical resemblance.7 In the Descent of Man too, Lamarck is mentioned only once.8 And in Variation of Animals and Plants under Domestication, Lamarck is not mentioned at all9 This is the pattern in all Darwin’s publications; Lamarck is either condemned or ignored.

Reaction in Private

In his second “Transmutation Notebook,” written for private use, Darwin repeats Lyell’s condemnation of Lamarck: “Lamarck’s

5. Francis Darwin, ed., The Life and Letters of Charles Darwin (New York: D. Appleton, 1887), II, 199.

6. Charles Darwin, Journal of Researches (London: John Murray, 1845), p. 52.

7. Charles Darwin, Origin of Species (New York: D. Appleton, 1898), p. 236. 8. Charles Darwin, Descent of Man, 2nd ed., rev. (New York: D. Appleton,

1898), p. 390. 9. Charles Darwin, Variation of Animals and Plants under Domestication

(New York: D. Appleton, 1898).

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willing [doctrine] ‘absurd, not applicable to plants,” lo but in the back of this Notebook he reminds himself to read Lamar&s PhiZoso- phie zoologique in the original (May 18, 1838).l’ Shortly thereafter his private comments about Lamarck change in tone. On page 119 of his second Notebook he compares Lamarck to James Hutton, the theoretical geologist whose ideas Lyell had made acceptable to the scientific community by marshaling three volumes of supporting evidence. Darwin seems to suggest that he will do for Lamarck what Lye11 has done for Hutton; he will gather data to prove Lamarck correct: “Lamarck was the Hutton of Geology, he had few clear facts, but so bold & many such profound judgment that he foreseeing con- sequence was endowed with what may be called the prophetic spirit in science. The highest endowment of lofty genius.” l2

Nowhere else in his notebooks does Darwin express such unbridled admiration for Lamar&s genius, but nowhere else does he make further derogatory comments. Rather, he pays Lamarck the subtle compliment of referring to his works when pondering a difficult question. Hence, on page 168 of the second Notebook Darwin asks, “did Lamarck connect extermination of some forms with his views”? On page 69 of the third Notebook: “Seeing what Von Buch (Humboldt) G. St. Hilaire, & Lamarck have written I pretend to no originality of idea - (though I arrived at them quite independently & have used them since).”

In the fourth Notebook there is the same tone of respect: “Looking over Lamarck surprised to see how many Tropical genera come from New Holland,” Darwin notes on page 46; and on page 145 he reminds

himself to check with Lamarck once again, “vide Lamarck vol. II p. 115 four laws.” Three pages later we read: “The law of generation is only modification, though important one of growth. Lamarck vol. II, p. 120.” And finally, on page 1.59, Lamarck is once again the authority Darwin looks up to: “Lamarck vol. II, p. 152 Philosophie zoologie says it is not sufficiently proved that any shell fish is really hermaphrodite.”

In his early years of working on the species question, Darwin echoes Lyell’s condemnation. However, by the time he fills the second, third,

10. “Darwin’s Notebooks on Transmutation of Species,” ed. with intro. by Gavin de Beer, Bull. Brit. Mus. (Nat. Hist.), Hist. Ser., 2 (1960). Darwin’s pagination: C, 63.

11. C,269. 12. c, 119.

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and fourth Transmutation Notebook, Darwin seems to have held a rather different view - which is not surprising when we consider that he was developing at that time a theory almost identical to that of Lamarck.

The Significance of the Darwin-Lamarck Relationship

J. C. Greene, in an essay clarifying Kuhn’s paradigm theory, has recommended studying Darwin’s relation to Lamarck for what it reveals about the role of external factors in the history of evolutionary theory. “The question remains as to what role, if any, Lamar&s theory played in the eventual emergence of the Darwinian counter- paradigm. It is fashionable nowadays to deny Lamarck any status as a percursor of Darwin, but we had best postpone this question of the influence of Lamar&s revolution manque on Darwin’s reol- h&ion veritable until we deal with developments in Britain,” Greene writes. “Suffice it to say for the moment that Lamar&s ideas haunted natural history during the first half of the nineteenth century much as the spectre of communism haunted social theory in the second half.” r3

Other Darwin scholars have recognized the importance of clarifying the Lamarck-Darwin relationship, while simultaneously warning of the difficulties involved. In his article on Darwin’s early theories David Kohn remarks, “The question must arise, was Darwin influenced directly by Lamarck with respect to these two issues: the precedence of habit over structure and the doctrine of use? A definitive answer to that question turns out to be very difficult to extract from the notebooks.” i4

In 1964 I received a grant from the National Science Foundation to analyze the contents of Darwin’s four Transmutation Notebooks. The computer revealed a sudden shift in Darwin’s vocabulary toward the end of the first Notebook. The word “habit” rose in frequency from three mentions in the first Notebook to sixty-three in the second, the fastest frequency change of any word during the two years Darwin

13. J. C. Greene, Science, Ideology and World View Berkeley: University of California Press, 1981), p. 43.

14. David Kohn, “Theories to Work By: Rejected Theories, Reproduction, and Darwin’s Path to Natural Selection,” Stud. Hist. Biol., 4 (1980), 131. For a

review of the literature on the Darwin-Lamarck relationship see Maxine Sheets- Johnstone’s amusing article, “Why Lamarck Did Not Discover Natural Selection,” J. Hist. Biol., 15 (1982), 443-465.

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was working out the rudiments of his theory. Correlation analysis revealed that related words also rose in frequency, so that it became evident Darwin was beginning to replace his first “isolation” theory with a new “habit” theory. r5 Naturally, I assumed that the shift had been caused by his reading of Lamarck in the original, but closer examination of the Notebooks revealed a surprise.

DARWIN’S RELATION TO THE REVEREND WILLIAM KIRBY

The French Language Problem

“Then how should I manage all my business if I were obliged to go every day walking with my wife. - Eheu!! I never should know French _ . . ,” l6 Darwin notes on the back of an envelope after re- turning from the voyage of the Beagle. He was not just being modest about his French. On pages 113-l 14 of his first Transmutation Note- book are a number of references to Etienne Geoffroy-St. Hilaire’s Principe de philosophie zoologique, which Darwin was trying to read in French. “I cannot understand whether S. H. thinks development in quite straight line or branching. - S. H. What does the expression mean . . . ,” Darwin puzzles. “I cannot make out his ideas about pro- pagation.”

Later, of course, Darwin did learn French, and he did read Lamarck in the original; but his knowledge of Lamar&s ideas during the first year he worked on his transmutation theories was through secondary soucres, because Lamar&s Philosophie zoologique had not been translated.

In his Autobiogrephy Darwin mentions that he was first introduced to the ideas of Lamarck by an older friend, Dr. Edmond Grant. “He one day, when we were walking together burst forth in high admiration of Lamarck and his views on evolution,” Darwin writes. “I listened in silent astonishment, and as far as I can judge, without any effect on my mind.” l7 Darwin was nineteen at the time, and we have no reason to doubt his assessment; but his next two sources of information

15. G. Grinnell, The Darwin Case: A Computer Analysis of Scientific Crea- tivity (Ann Arbor, Michigan: University Microfilms, 1969), graphs 7, 8, 9, following p. 37.

16. Nora Barlow, ed., The Autobiography of Charles Darwin (London: John

Murray, 1958), p. 234. For more on the French probelm see Silvan Schweber, “The Origin of the Origin Revisited,“J. Hist. BioZ., 10 (1977), 289n135.

17. Autobiography, p. 49.


about Lamarck’s theory are more difficult to evaluate. One is Charles Lyell’s Principles of Geology, volume 2, which Darwin received in the autumn of 1832 while aborad the Beagle at Montevideo; the other is the Reverend William Kirby’s Bridgewater Treatise, On the Power, Wisdom and Goodness of God as Manifested in the Creation of Animals and in Their History, Habits and Instincts, which he read shortly after beginning his first Transmutation Notebook in the summer of 1837.

Both Lyell and Kirby condemn Lamarck, but there is a question in the minds of most scholars about the sincerity of Lyell’s disdain. Kirby, on the other hand, was completely opposed to Lamarck, both on scientific and on theological grounds. So violent and so sweeping were Kirby’s attacks that Darwin, in order to defend his own position, began reinterpreting Kirby’s data to the point where his own theory began to resemble Lamarck’s.

Kirby’s Attack on Lamarck

As an Anglican divine, as the rector of Barham, as the recipient of a bequest of 1,000 pounds sterling to illustrate the power, wisdom, and goodness of God in his creation, and as one of England’s oldest and most notable naturalists, the Reverend William Kirby felt obliged to point out the most glaring of Lamarck’s errors: “As Lamar&s hypothesis relates particularly to the animal kingdom,” Kirby writes, “I shall make a few observations upon it, calculated to prove its utter irrationality.” r* These few observations went on for 1,053 pages in two volumes, including a 105 page theological introduction.

“Lamar&s great error, and that of many other of his compatriots, is materialism,” Kirby explains. “He seems to have no faith in anything but body, attributing everything to a physical, and scarcely anything to a metaphysical cause. Even when, in words, he admits the being of a God he employs the whole strength of his intellect to prove that he had nothing to do with the works of creation.“r9

“Instincts,” “ gravity,” even “life” itself, were for Kirby intermediate between the material world and God in that they are responsible for holding the harmonic balance between conflicting forces. If gravity

18. William Kirby, On the Power, Wisdom and Goodness of God as Mani-

fested in the Creation of Animals and in Their History Habits and Instincts (London: William Pickering, 1835), p. xxiv.

19. Ibid., p. xxvii.

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were removed from the creation, the planets would fly off into chaos; there would be no order in the heavens. By the same token, if animals lost their instincts, birds would no longer build their nests, or migrate, or learn to fly. Bears would not know when to hibernate, nor salmon when to be driven upstream to spawn; the entire animal kingdom would be thrown into disarray. Similarly, if the spirit of life were removed, all creatures would devolve into their material constituents and the planet would be dead like the moon. For Kirby, instincts, gravity, and life mediated between the material creation and God. They were, in effect, angels of the Lord, expressions of his love for his creation, or “cherubs” - being neither God himself, on the one hand, nor mere material bodies on the other. Kirby’s objection to Lamarck was that Lamarck had attempted to reduce these spiritual forces in nature to mere material causes. He writes:

One of my objects in treating so much at large upon this my- sterious subject, was to counteract that tendency, often observable in the writings of philosophers, to ascribe too much to the action of second causes, and the mechanisms of the heavenly powers; as if they were sufficient of themselves, and without the intervention of the First Cause, to do all in all, and keep the whole machine and all its parts together and at work. Instead of regarding Him as receding further and further from our observation, my desire is to bring Him nearer and nearer to us, that we may see and acknowledge Him everywhere, as the main-spring of the universe, which animates, as it were and upholds it in all its parts and motions - “Lives through all life, extends through all extent Spreads undivided, operates unspent.” Maintaining his own laws by his own universal action upon and by his cherubim of glory. WITHOUT HIM THEY CAN DO NOTHING.”

Thus wherever Lamarck attempts to ease God out of the creation, Kirby is at pains to bring him back in. They look at the same data, but Kirby sees “Cherubim” whereas Lamarck sees only the “habits” of animals developed in response to “circumstances.” “The great object both of LaPlace and Lamarck seems to be to ascribe all the works of creation to second causes; and to account for the production

20. Ibid., pp. cii, ciii

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of all the visible universe, and the furniture of our own globe, without the intervention of a first.“z1

Darwin 3 Response to Kirby

Darwin’s assessment of Kirby’s theology is unflattering. In the first Transmutation Notebook, Darwin notes that “Kirby all through Bridgewater errs greatly.“22 Later in the same Notebook he writes, “Has the Creator since the Cambrian formation gone on creating animals with same general structure. - Miserable limited view.“23

In the second Notebook, Darwin chides himself jokingly for being a “materialist” in defiance of Kirby’s condemnation: “- Love of the deity effect of organization, oh you materialist! . . . - Why is thought being a secretion of brain, more wonderful than gravity a property of matter?“%

In the third Notebook, Darwin again attacks Kirby’s imagination. “- How far grander than idea from cramped imagination that God created . . . a long succession of vile molluscous animals. How beneath the dignity of him, who is supposed to have said let there be light & there was light. - whom it has been declared ‘he said let there be light & there was light’ - bad taste.“25

In the fourth Notebook, discovering in the writings of Charles Babbage and Sir William Herschel a world view compatible with his own, Darwin breaks out with a cheer: “Babbage 2 nd Edit. p. 226 - Herschel calls the appearance of new species the mystery of mysteries, & has grand passage upon the problem! Hurrah - ‘intermediate causes.’ “26

Darwin’s theological position differs from that of Kirby, but is similar to that of Lamarck. Kirby writes, “Another object which Lamarck considers as constituting nature is Law. But law considered abstractly is also nothing.“27 Darwin once again finds himself tarred with the same brush. In his first Transmutation Notebook, Darwin avows his faith in “intermediate causes” or “laws.” “Astronomers might formerly have said that God ordered each planet to move in

21. Ibid., p. xxiv. 22. B,141. 23. B,216. 24. C,166. 25. D,31. 26. E,59. 27. Kirby, On the Power, p. xxxvii.

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its particular destiny. In same manner God orders each animal created with certain form in certain country, but how much more simple and sublime power let attraction act according to certain law, such are inevitable consequences - let animal be created, then by the fured laws of generation, such will be their successors.“28

He reiterates the same theme in the second Notebook: “These questions may be all disputable, but the one end of classification [is] to express relationship & by so doing discover the laws of change in organization.” 2g

Again, in the third Notebook: “Reducing facts to law only merit if merit there be in following work.“3o

And in the fourth Notebook: “the great end must be the law and causes of change .” 31

The same leit motif runs through his “Sketch,” his “Essay,” and the Origin. Quoting W. Whewell, Darwin opens the Origin of Species with: “But with regard to the material world, we can at least go so far as this - we can perceive that events are brought about not by insulated interpositions of Divine power, exerted in each particular case, but by the establishment of general laws.’ “32 However, it was one thing to declare the theology of secondary causes more “simple and sublime,” it was another thing to take Kirby’s two volumes, crammed full of illustrations of the extraordinary instincts of a myriad of animals, and to explain them in terms of material causes.

Karl Popper has stressed that great scientists are frequently stimulated by the challenge of a “culture clash,” and Kirby and Darwin seem to be no exception. Just as Kirby’s two volumes were written to refute the materialistic world view of the French revolutionaries

28. B, 101. 29. C,158. 30. D,69. 31. E,52. 32. Origin (London: John Murray, 1859), facing title page. For more on

Darwin’s relation to Anglican natural theology see Neal Gillespie, Charles Darwin and the Problem of Creation (Chicago: University of Chicago Press, 1979); Dov Ospovat, The Development of Darwin’s Theory: Natural History, Natural Theology, and Natural Selection, 1838-59 (Cambridge: Cambridge University Press, 1981); Edward Manier, The Young Darwin and His Cultural Circle (Dord- recht, Holland: D. Reidel, 1978); Peter J. Bowler, “Darwinism and the Argument from Design,” J. Hist. Biol., 10 (1977), 29-43; and esp. Robert J. Richards, “Instinct and Intelligence in British Natural Theology: Some Contributions to Darwin’s Theory of the Evolution of Behavior,*’ J. Hist. Biol., 14 (1981), 193- 230.

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(Laplace and Lamarck), Darwin’s theory was generated by his clash with Anglican theologians (Kirby and Malthus). In the end, Darwin revived Lamar&s theory - although he arrived at it, as he says, quite independently.

THE RISE OF DARWIN’S SECOND THEORY

Kirby’s Scientific Clash with Lamarck

“Perhaps the followers of Lamarck may say that, in the present instance, the animal constructs its own float itself, at the impulse of its own wants,” Kirby conjectures. “But uninstructed by its Creator, how could it learn that vesicles full of air would serve to float its little boat?“33 Kirby is referring to the practice of the violet snail, Ianthina, of secreting a membrane that it inflates to float upon the sea. His two-volume work is full of remarkable stories about the instincts of animals such as the water spider, which builds a diving bell under water and fills it with air by attracting bubbles to its belly.

“How these little animals can envelope their abdomen with an air-bubble, and retain it till they enter their cells, is still one of Nature’s mysteries that have not been explained,” Kirby notes. “We cannot help, however, admiring and adoring the Wisdom, Power, and Goodness manifest in this singular provision, enabling an animal that breathes the atmospheric air, to till her house with it under the water.“34

According to Kirby, there are really three different types of instincts, although all stem from the same source - God. The first type are those designed for the self-preservation of the individual; the second type are the sexual instincts, which do the individual little benefit, but serve to propagate the species; and the third type of instinct drives species to produce a superabundance of offspring for the benefit of the food chain. The impulse to reproduce, Kirby feels, must come from outside the animal, for it does not benefit the individual as such. Indeed, many animals in the process of reproducing run great risk to themselves.

Kirby illustrates his point by describing the sexual migrations of animals - such phenomena as schools of salmon swimming upstream, or land crabs migrating down to the sea. The effectiveness of his argument is based on logic, well embroidered with rhetoric. Note how

33. Kirby, On the Power, I, 294.

34. Ibid., II, 297.

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land crabs of the West Indies, Gecurcinus curnifex, appear to be impelled by forces beyond their own control as they struggle to the sea to spawn: “In May and June, when the rainy season takes place, their instinct impels them to seek the sea, that they may fulfill the great law of the Creator, and cast their spawn,” Kirby writes. It is not so much what he says as the way he says it:

They descend the mountains, which are their usual abode, in such numbers, that the roads and woods are covered with them. They feel an impulse so to steer their course, that they may travel by the easiest descent, and arrive most readily at the sea, the great object at which they aim. They resemble a vast army marching in battle array, without breaking their ranks, following always a right line; they scale the houses, and surmount every other obstacle that lies in their way.35

Kirby gives force to his argument by the collective action of these and other creatures; but his most remarkable argument, and the one that is to have the most profound effect on Darwin, is his third cate- gory of instincts - the superabundance of offspring. According to Kirby, a single oyster will lay as many as 1.2 million eggs; a single codfish as many as 9 million; and all creatures, in both the plant and animal kingdoms, produce many more offspring than are required to continue the species. Although Darwin is to reinterpret this phe- nomenon, Kirby sees it as another incidence of providential wisdom. The abundance of offspring provide the links in the food chain. For Kirby, the “tree of life,” as described in Genesis, represents the de- pendence of all creatures on one another. The food for the tree of life originally comes from the sun, but it is transformed by the plant kingdom into food for animals, which in turn reproduce with an abundance of offspring such that all creatures have something to eat. Summing up at the end of the second volund volume, Kirby concludes:

In our ascent from the most minute and least animated parts of that Kingdom to man himself, we have seen in every department that nothing was left to chance, or the rule of circumstances, but everything was adapted by its structure and oranization for the situation in which it was to be placed, and the functions it was

35. Ibid., I, 126,127.

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to discharge; that though every being, or group of beings, had separate interests, and wants, all were made to subserve a common purpose, and to promote a common object; and that though there was a general and unceasing conflict between the members of this sphere of beings, introducing apparently death and destruction into every part of it, yet that by this great mass of seeming evil pervading the whole circuit of the animal creation, the renewed health and vigour of the entire system was maintained. A part suffers for the benefit and salvation of the whole, so that the doctrine of the sufferings of one creature, by the will of God, being necessary to promote the welfare of another, is irrefragably estab- lished by everything we see in nature; and further that there is an unseen hand directing all to accomplish this great object, and taking care that the destruction shall in no case exceed the necessity.36

Kirby closes by reciting the 104th Psalm, the favorite of all British naturalists since the time of John Ray. “Oh Lord, how manifold are thy works in Wisdom hast thou made them all; the earth is full of thy riches.” Earlier, Kirby has fallen to his knees overwhelmed by the magnificence of the creation: “But I lose myself in infinite amazement; I shrink into very nothingness, when I reflect that such a miserable worm as I am, so fallen and corrupted, should presume to lift its thought so high and lose itself in the depths of the unfathomable ocean of Deity.” 37

Compared to this feeling of awe, Kirby found Lamarck’s system unappealing, a product of human ego.

It is much to be lamented that many bright lights in science, some from leaning too much to their own understanding, and others probably from having Religion shown to them, not with her own winning features, nor in her own simple dress, but with a distorted aspect, and decked meretriciously, so that she appears what she is not, without further inquiry and without consulting her genuine records, have rejected her and fallen into grievous errors. To them might be applied our Saviour’s words, Ye do err not knowing the Scriptures. These observations apply particularly to two of the most eminent philosophers of the present age, one for the depth of his knowledge in astronomy and general physics; and the other in zoology. It will be

36. Ibid., II, 526. 37. Ibid., I, 231.

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easily seen that I allude to LaPlace and Lamarck, both of whom, from their disregard of the word of God, and from seeking too exclusively their own glory, have fallen into error of no small magnitude.38

Darwin 5 Reinterpretation of Kirby’s Instinct Theory

“Reflect much over my view of particular instinct being memory transmitted without consciousness,” Darwin writes in his second Transmutation Notebook. “An action becomes habitual is probably first stage, & an habitual action . . . may be called instinctive.“39 According to Darwin, an animal would be driven to change its habits owing to circumstances. If these new habits persisted over a long time, they would appear as instincts and would eventually result in a change of anatomical structure. “We even see they must be done often to be habitual,” he writes. “Structure is only gained slowly. Therefore it can only be those actions which many successive genera- tions are impelled to do in same way.“4o Like Kirby, Darwin uses the word “impel,” but while for Kirby it is God that does the im- pelling (“but the almighty by an irresistible agency, impels them to it”), for Darwin it is circumstances, or, as Lamarck would say in French, “circonstances.“41

Darwin was well aware that some of the instincts of animals were not easily explicable in terms of a response to circumstances, but he was willing to try to develop such explanations. “Insects shamming death most difficult case to imagine how art acquired,” Darwin acknowledges on page 197 of the second Notebook, and then cautions himself not to waste time on the complex cases. “Only reason however on this to a degree,” he reminds himself, but two pages later he is faced with another problem. “Is not squirrel hoarding & killing grain acquirable through hoarding from short time,” he questions. “My theory must encounter all these difficulties, knowing that animals have some reason, & actions habitual. It surely is not worthy inter- position of deity to teach squirrel to kill ears of corn. According to my views, habits give structure, habits precede structure, habitural instincts precede structure.“42

38. Ibid., I, xix, xx. 39. c, 171. 40. Ibid. 41. Jean B. Lamarck, Philosophic zoologique (Paris: Chez Dentu, 1809), I,

218-268. 42. C, 199.

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Rather than attempt to explain all the instincts of animals that Kirby had elaborated, Darwin chose to concentrate on the simpler ones, like the instinct of salmon to jump cataracts in order to reach their spawning grounds. “Young salmon first a species which lived in estuaries. Its tastes taught it to go to salter water (& its necessities teach it taste, but that a much more general argument) & therefore down the stream follow ebb tide, therefore got into habit of going down stream which would last were the stream 1000 miles long,” Darwin suggests.43

“According to my view because actions are constant, they are instincts and not instincts constant.“44 His strategy was to explain the simpler instincts, and then to argue against the divine origin of other instincts by analogy. “Grant that one instinct can be acquired . . . & whole fabric totters & falls. - Look abroad, study gradation, study unity of type, study geographical distribution, study relation of fossil with recent. The fabric falls!“45

Darwin combed the literature for facts to support his theory: “Wilsons’ American ornithology a mine of valuable facts, regarding

habits range & all kinds of information, instinct.“46 “Dr. S. has some remarkable crochets about instincts whenever

instinct is mentioned some definition must be given.“47 “Shows instinct (Sir J. Sebright admirable essay) . . . wild ducks -

lose as well as gain instincts. Wild & tame rabbit good instance - instincts of many kinds in dogs as clearly applicable to formation of instincts in wild animals . . . external circumstances in both cases effect it. - Sir J. Sebright excellent authority.“48

“Study Bell on Expression & the Zoonomia, for if the former shows that if a man grinning is to expose his canine teeth (this may be made a capital argument if man does move muscles for uncovering canines), no doubt a habit gained by formerly being a baboon with great canine teeth. - Blend this argument with his having canine teeth at all. - This way of viewing the subject important.“49

Darwin even went so far as to perform an experiment to test his theory:

43. c, 212. 44. C,232. 45. C, 16-11. 46. C,69. 47. c, 150. 48. C, 134. 49. (2,243.

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Case of habit: I kept my tea in right hand side for some months, & then when that was finished kept it in left, but I always for a week took off cover of right side though my hand would sometimes vibrate seeing no tea brought back memory - old habit of putting tea in pot, made me go to tea chest almost unconsciously.50

But not all of Darwin’s research was supportive. At the time he was working up his habit theory of transmutation, he was in contact with John Gould, ornithologist for the Royal Zoological Society, who had been given the job of classifying the birds collected during the Beagle voyage. “Gould seems to doubt how far structure & habits go together,” Darwin acknowledges. “This must be profoundly considered. - Structure may be obliterating, whilst habits are changing, or structure may be obtaining, whilst habits slightly preceed them.“51

Although the Darwin-Lamarck habit theory is probably incorrect, Darwin exhibited considerable ingenuity in explaining away the anomalies. Atavism, he suggests, may be analagous to memory: similar circumstances triggering similar responses.

What are those marvellous cases where you feel sure you have heard conversation before, is strong association recalling up image which had been past. . . My view of instinct explains its loss? if it explains its acquirement. - Analogy a bird can swim without being web footed yet with much practice & led on by circumstance it becomes web footed. Now man by effort of memory can remember how to swim after having once learnt, & if that was a regular contingency the brain would become web-footed & there would be no act of memory.52

Mutations provided Darwin with a more difficult challenge, for mutations tend to reveal themselves as complete structures without any slow development by habits (the sixth finger on a hand, for instance) a problem that worried Darwin considerably. He got around it by suggesting that there were two mechanisms for change in species - one was habit induced, the other “fortuitous” variation. Fortuitous variation he viewed as relatively insignificant, on the ground that characteristics that appear suddenly would disappear as quickly. “One

50. C,217. 51. C,81. 52. C, 172-173

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can perceive that natural varieties or species, all the structure of which is adaptation to habits (& habit second nature) may be more in con- stitutional, - more conformable to the structure which has been adapted to former changes than a mere monstrosity propagated by art .” 53

By the time Darwin had reached his third Notebook on the transmutation of species, he had gained considerable confidence in his theory. “Mine is a bold theory, which attemp [t] s to explain, or asserts to be explicable every instinct in animal~.“~~ Still, there were a number of difficulties. Atavism was one, so were mutations such as the appearance of feathery tufts, on the legs of pouter pigeons, also the flamboyant tail feathers of the birds of paradise, Even more difficult was the evolution of sexual organs and the formation of vertebrae. “It is a difficulty how a different number of vertebrae are produced when (& in all such structures) there cannot be gradation. See what Eytons young pigs - if vertebra much lengthened.“55

Although Darwin could explain away all anomalies, or at least accommodate himself to the anomalies one way or another, he was aware that his argument was not completely convincing. “Mention persecution of early Astronomers,” Darwin suggests to himself after seeing himself crucified by the facts of natural history, “then add chief good of individual scientific men is to push their science a few years in advance only of their age, (differently from literary men,) must remember that if they believe & do not openly avow their belief they do as much to retard as those whose opinion they believe have endeavoured to advance cause of truth. It is of the utmost importance to show that habits sometimes go before structure.“56

THE FALL OF DARWIN’S HABIT THEORY

The Malthusian Challenge

Although the human female is not so fecund as an oyster, she nonetheless is capable of producing fifteen or twenty offspring in the course of her productive career, and many have done so. The Methodist reformer John Wesley was one of nineteen children; so was

53. D, 107. 54. D, 26. 55. C, 124. 56. C, 123-124.

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the eighteenth-century architect van Brugh. Saint Catherine of Siena was one of twenty-two, and the Duke of Milan in the fifteenth century had as many aunts and uncles. Today the population of Kuwait is growing at 4 percent annually, which means that in 156 years its population will exceed the current population of the world.

Like other animals, man is impelled to breed; but unlike other animals, man is able to kill and to eat without being killed and eaten in turn. The checks on man’s fecundity therefore must come from within. Morality is to man what instincts are to animals; it preserves his balance with nature. Just as the Reverend William Kirby claims that instincts are a spiritual force intermediate between God and the creation, so also does the Reverend Thomas Robert Malthus argue that morality is its human analogue. Remove the instincts of animals, and remove morality from man; the result is the same.

Darwin’s reaction to Mahhus was similar to his reaction to Kirby, and for the same reason. The Tory-Anglican theology of the two men offended what he called his “Whig principles.“s7 “ ‘It accords with the most liberal! spirit of philosophy to believe that no stone can fall, or plant rise without the immediate agency of the deity’,” Malthus writes on page 529 of his Essay. Darwin, however, in copying the passage into his notebooks, is indignant with Malthus for misusing the word “liberal.” “ ‘ But we know from experience! that these opera- tions of what we call nature, have been conducted almost! invariably according to fured laws’.” Darwin furiously underlines and indignantly superimposes exclamatory editorial comments onto the text.s8 ‘And since the world began, the causes of population & depopulation have been probably as constant as any of the laws of nature with which we are acquainted.’

Earlier, immediately after reading Kirby, Darwin had worked out a theory of natural selection by means of population pressure, which the Malthusian challenge once again brought to the surface. “This applies to one species - I would apply it not only to population & depopulation, but extermination & production of new forms.“s9

51. Nora Barlow, ed., Darwin and Henslow: The Growth of an Idea (London: John Murray, 1967). “The Captain does everything in his power to assist me, & we get on very well. - but I thank my better fortune he has not made me a renegade to Whig principles” (Charles Darwin to the Reverend Professor Henslow from Rio de Janeiro, May 18, 1832). For more on Darwin’s Whig principles see Schweber, “Origin Revisited.”

58. E,3. 59. Ibid. Compare Darwin’s reaction to Malthus with his reaction to Kirby

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Several pages later he reiterates the same theme: “When two races of men meet, they act precisely like two species of animals. - They fight, eat each other, bring diseases to each other &c., but then comes the most deadly struggle, namely which have the best fitted organization, or instincts (i.e., intellect in man) to gain the day.“(jO And again, several pages later, “There ought to be no weeding or encouragement, but a vigorous battle between strong & weak.“61 A few pages further: “Seeing the beautiful seed of a Bull Rush I thought, surely no ‘fortuitous’ growth could have produced these innumerable seeds, yet if a seed were produced with infinitesimal advantage it would have better chance of being propagated & so etc.“62

For some time Darwin maintained his habit theory, along with his third theory, that of natural selection of fortuitous variations: “Varieties are made in two ways,” he writes, “- local varieties when whole mass of species are subjected to same influence . . .; but grey- hound, race-horse & poulter Pidgeon have not been thus produced.“63 In the fourth Notebook, we hear less and less about the habit theory and more and more about poulter pigeons and birds of paradise whose plumage is not easily explicable in terms of a change in habits. “All that we can say in such cases is that the plumage has not been so injurious to bird as to allow any other kind of animal to usurp its place - & therefore the degree of injuriousness must have been ex- ceedingly small. - This is far more probable way of explaining, much structure, than attempting anything about habits.“@

Although Darwin appears to abandon his habit theory in the middle

(B, 147-148): “If population was increasing. . . At present day in looking at two fine families one will [have] successors for centuries, the other will become extinct. - Who can analyse cause. . . May this not be extended to all animals.”

60. E, 63-64. For more on the Darwin-Malthus relationship see Gertrude Hiimelfarb, Darwin and the Darwinian Revolution (Garden City, N.Y.: Double-

day, 1962): “As surely as Marx stood Hegel on his head, so Darwin did to Malthus” (p. 163). Also Frank N. Egerton, “Studies of Animal Populations from Lamarck to Darwin,” J. Hist. Biol., I (1968), 225-259; idem, “Humboldt, Darwin, and Population,” J. Hist. BioI., 3 (1970), 325-360; Peter J. Vorzimmer, “Darwin, Malthus, and the Theory of Natural Selection,” J. Hist. Ideas, 30 (1969), 527-542; Robert M. Young, “Malthus and the Evolutionists: The Com- mon Context of Biological and Social Theory,” Past and Present, 43 (1969) 109-145; Schweber, “Origin Revisited.”

61. E, 112.

62. E, 137. 63. E,llS. 64. E, 147.

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of his fourth Transmutation Notebook (the word “habit” appears only 4 times in it, compared with 63 mentions in the second Note- book), the abandonment is not categorical. The theory surfaces again in the Origin of Species, although somewhat modified and reconciled with natural selection, as can be seen in the following passage about the bear turning itself into a whale by swimming around in a river chasing insects: “In North America the black bear was seen by Hearne swimming for hours with widely open mouth, thus catching, like a whale, insects in the water. Even in so extreme a case as this, if the supply of insects were constant, and if better adapted competitors did not already exist in the country, I can see no difficulty in a race of bears being rendered by natural selection more and more aquatic in their structure and habits, with larger and larger mouths, till a creature was produced as monstrous as a whale.“65

In tha above passage Lamar&s theory of habits is not so much replaced by the theory of natural selection as it is supplemented. Compare the above passage with one found in Darwin’s second Trans- mutation Notebook. The similarity is striking, although in this case Darwin is talking about a jaguar’s turning itself into an otter: “Fish being excessively abundant & tempting the Jaguar to use its feet much in swimming, & every development giving greater vigour to the parent tending to produce effect on offspring -but whole race of that species must take to that particular habitat. - All structures either direct effect of habit, or hereditary & combined effect of habit.“&

Although he removed the story about the bear from later editions of the Or&in, he continued to develop and articulate the habit theory.67 In the last chapter of Variations of Animals and Plants under Domesti- cation Darwin outlines his provisional hypothesis of “pangenesis,” which he hopes will provide the mechanism by which acquired char- acters may be inherited. “The units of the body are generally admitted by physiologists to be autonomous. I go one step further and assume they throw off reproductive gemmules. Thus an organism does not generate its kind as a whole, but each separate unit generates its kind.“68

The pangenesis hypothesis was severely criticized, and experiments

65. Origin of Species, 1st ed., p. 184. 66. C,63. 67. Charles Darwin, The Variation of Animals and Plants under Domestica-

tion, 2nd ed. rev. (London: John Murray, 1885), II, chaps. 22,24. 68. Ibid., II, 398.

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with blood transfusions between different varieties of rabbits proved negative; but Darwin stuck with the theory to the end. “I certainly should have expected that gemmules would have been present in the blood,” ‘Darwin acknowledges, “but this is no necessary part of the hypothesis, which manifestly applies to plants and the lowest animals.” 69

Later, Morgan’s work with Drosophila and mathematical models in population genetics led to the abandonment of the Darwin-Lamarck habit theory of evolution.”

CONCLUSION

“The difficulty of discussion between people brought up in different frameworks is to be admitted,” Karl Popper writes. “But nothing is more fruitful than such a discussion; than the culture clash which has stimulated some of the greatest intellectual revolutions.“71 Certainly Kirby and Darwin were brought up in different cultures - Kirby with his Anglican-Tory orientation, Darwin with his Whig-liberal background - and certainly the clash generated some interesting theories; but it also resulted in the revival of Lamarck’s discredited habit theory, which took another century of careful experimentation to weed out.

69. Ibid., II, 350. 70. Garland E. Allen, “Thomas Hunt Morgan and the Problem of Natural

Selection,” J. Hist. Biol., I (1968), 113-140; William B. Provine, “The Role of

Mathematical Population Geneticists in the Evolutionary Synthesis of the 1930’s and 1940’s,“Stud. Hist. Biol., 2 (1978), 167-192.

71. Karl Popper, “Normal Science, and Its Dangers,” in Criticism and the Growth of Knowledge, ed. Imre Lakatos and Alan Musgrave (New York: Cam- bridge University Press, 1976), p. 57.

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