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National Academy of Sciences (US); Avise JC, Ayala FJ, editors. In the Light of Evolution: Volume III: Two Centuries of Darwin. Washington (DC): National Academies Press (US); 2009.

In the Light of Evolution: Volume III: Two Centuries of Darwin.

• Hardcopy Version at National Academies Press

14 The Darwinian Revolution: Rethinking Its Meaning and Significance

Department of Philosophy, Florida State University, Tallahassee, FL 32306.

MICHAEL RUSE

The Darwinian revolution is generally taken to be one of the key events in the history of Western science. In recent years, however, the very notion of a scientific revolution has come under attack, and in the specific case of Charles Darwin and his Origin of Spe cies there are serious questions about the nature of the change (if there was such) and the specifically Darwinian input. This chapter considers these issues by addressing these questions: Was there a Darwinian revolution ? That is, was there a revolution at all? Was there a Darwinian revolution? That is, what was the specific contribution of Charles Darwin? Was there a Darwin ian revolution ? That is, what was the conceptual nature of what occurred on and around the publication of the Origin ? I argue that there was a major change, both scientifically and in a broader metaphysical sense; that Charles Darwin was the major player in the change, although one must qualify the nature and the extent of the change, looking particularly at things in a broader historical context than just as an immediate event; and that the revolution was complex and we need the insights of rather different philosophies of scientific change to capture the whole phenomenon. In some respects, indeed, the process of analysis is still ongoing and unresolved.

T hirty years ago I (Ruse, 1979) published a book with the main title The Darwinian Revolution . No one questioned whether or not I had a real topic. There was a Darwinian revolution and my book was about it. Today, one could not be so sure. The idea of scientific revolutions has been questioned; Darwin’s contribution has been challenged; and even if you can come up positively on these matters, what on earth are we talking about anyway? These are the 3 questions I shall address in this article.

• WAS THERE A DARWINIAN REVOLUTION?

Historian Jonathan Hodge (2005) has been one of the strongest naysayers on this matter. He thinks that the whole talk of scientific revolutions, something of an obsession by many historians and philosophers of science in the years after Thomas Kuhn’s engaging and influential The Structure of Scientific Revolutions (1962), is deeply misleading. The term is obviously taken by analogy from politics and even there it is doubtful that there are such things (at least that there are such things with common features) and in science likewise we have no reason to think that there are such things with common features. In any case, the talk is wrong-headed because it drives you to concentrate on some people and events and downplay or ignore other people and events.

In response, let us agree at once that focusing on revolutions (in science) does rather skew things in certain ways. Dwelling at length on Darwin carries the danger of ignoring the contributions of others in the 19th century, from the Naturphilosophen (people like the German anatomist Lorenz Oken who saw homologies everywhere) at the beginning to the orthogeneticists (people like the American paleontologist Henry Fairfield Osborn who thought that evolution has a momentum that carries it beyond adaptive success) at the end. Worse, it gives the impression that unless you have something dramatic and crisis-breaking, the science is of little value. Remember, the alternative to Kuhn’s revolutionary science is normal science, and this has (a perhaps undeserved) reputation of a 3-hour sermon by a Presbyterian minister on a wet Sunday in Scotland.

Against this, however, one can point out that the history of science as a professional discipline is little more than 50 years old and that you have to start somewhere. In the case of Darwin, even 30 years ago there was no real synthesis. The tragedy would have been if historians of science had stopped there and gone no further. But this is clearly not true. In the past 30 years or more, staying just with the history of evolutionary thinking, there has been a huge amount of work on people before and after Darwin, and on his contemporaries like Thomas Henry Huxley [for instance, Desmond (1999)]. To name but 3 researchers, one can pick out Robert J. Richards (1987, 1992, 2002, 2008b) and the work he has done on German evolutionary thinking in the 19th century, before and after Darwin; Peter Bowler (1976, 1984, 1988, 1996), who started with paleontology in the 18th century and since has written extensively on the post-Darwinian figures in the 19th century, now extending his grasp into the 20th century; and William Provine (1971, 1986), who has offered detailed and brilliant analyses of the impact of genetics on the understanding of evolution. It just has not been the case that focusing first on Darwin led us to an inescapable dead end with respect to the rest of evolution’s history.

Should we nevertheless persist with the term “revolution”? Well, it surely depends on the case to be made. Obviously we can legitimately use the term revolution somewhat generically in politics. No one thinks the American Revolution and the French Revolution were the same, but they did share characteristics that, for example, the move from Ronald Reagan as president to George H. W. Bush did not. There was a break from the old government and this was done by a group seizing power, leading to dramatic changes. I see no reason we should not extend the term metaphorically. Think of the technological revolution in the past 20 years or so. Laptop computers are commonplace, electronic use of libraries is the norm, and search engines like Google and Yahoo have transformed the gathering of information. If this does not all add up to a revolution of some kind, it is hard to know what does. There is as much of a break with the past as there was for an American ruled from Washington rather than London. At an immediate level, the change is probably even greater.

So if you want to extend the term revolution to science, if it captures something of what goes on, then all power to the use. But now the question is whether the Darwinian revolution merits the use. Was there a big break with the past, sufficiently significant to speak of revolution? Did something big, really big, happen around 1859, and does it still merit a special place in the history of evolutionary thought? In respects, our appreciation of what happened is even greater than it was 30 years ago: If you like, today in 2009 the 200th anniversary of Darwin’s birth as opposed to 1982, the 100th anniversary of Darwin’s death. Daniel Dennett (1995) has referred to Darwin’s idea about natural selection as the greatest ever. One could debate this (Plato’s theory of forms gives it a good run for its money), but all will certainly agree that something really big happened around and because of the Origin in 1859 (Darwin, 1859). But here, let us take note of some of Hodge’s worries. The basic question is: What are we talking about? In the Darwinian case there are 2 levels of activity and interest. Without pretending that the divisions are completely simon-pure, there is the level of science and the level of metaphysics (recognizing that this includes things that might be considered scientific at one end and religious or otherwise ideological at the other end).

On one hand, there is the scientific theory of evolution through natural selection, the central topic of the Origin . On the other hand, there is what scholars like Robert M. Young (1985), borrowing a title from Thomas Henry Huxley (1863), used to refer to as the debate over “man’s place in nature.” While today we would never dare to use that kind of language, in essence they got it absolutely right. At some level, the Darwinian revolution destroyed forever the old picture of humans as somehow miraculously special, symbolically and literally as touched by magic. Admittedly, to this day Christian fundamentalists (and those of other religions) refuse to accept this, but it is true. Even if you think that you can still be religious, a Christian even, you have to rethink dramatically, emotionally even more than intellectually, what it means to be a human. Starting with a certain modesty about ourselves (Ruse, 2001).

It is hard to know how one would respond to someone who questioned the significance of the changes at either of these 2 levels. At the level of science, changing over to the idea of evolution in itself is a massive change to make, whether you are moving from a Greek theory of eternal life without change or a more Christianized vision of the instantaneous appearance of life. And then you add in the mechanism of natural selection, used by at least 90% of today’s evolutionists, and you have an even greater break with the pre- Origin past. At the level of metaphysics, the change is yet deeper if that is possible. The violent opposition of the American above-mentioned fundamentalists or creationists shows that if anything could. It is not just a question of who we are but also of how we should live our lives (Ruse, 2005). Although it is hardly the only factor, Darwinian thinking is at the center of the move to modernism, in some broad sense. Are we still to be subject to the old ways (women inferior, gays persecuted, abortion banned) or are we to look forward to a truly post-Enlightenment world, with reason and evidence making the running in an entirely secular fashion?

Grant then that something big did happen. But are we right in putting it all on 1859 and the publication of the Origin of Species ? This raises my second big question. Divide the answer according to the levels of inquiry.

• WAS THERE A DARWINIAN REVOLUTION? SCIENCE

Start with one indubitable fact. There always have been and there always will be people who think that not only was Alfred Russel Wallace, the codiscoverer of natural selection, unappreciated but that Charles Darwin pinched all of the good ideas from the younger evolutionist. It should be called the Wallacean revolution with Charles Darwin but a minor footnote. [Brackman (1980) is the classic exemplification.] There are other candidates for the job. Edward Blyth, an English-born Indian naturalist, has long been a popular name. [Eiseley (1958) was the source for this one.] More recently, in an award-winning book, James Secord (2000) argued that really it was Robert Chambers, the anonymous Scottish author of the Vestiges of the Natural History of Creation (Chambers, 1844), who did the heavy lifting. Darwin came along at the end to inherit all of the glory. (Try www.darwin-legend.org for a cross-sample of these sorts of charges.)

There is little need to spend much time on these claims because basically they don’t hold much water. Let it be shouted out loud. Darwin did not steal from Wallace. Darwin’s ideas—the ideas of the Origin that is—are all right there in the 35-page Sketch of his ideas that he wrote in 1842 (Darwin and Wallace, 1958). There was some tweaking about the nature of adaptation; perhaps he hit in the early 1850s on the principle of divergence—although there are certainly hints of that in the species notebooks—but the mechanisms (natural and sexual selection) are there, as is the structure of the argument of the Origin (more on this in a moment). Even some of the flowery passages, notably the final paragraph about grandeur in views of life, can be found in the early writings. Wallace certainly stimulated Darwin to get moving, but that was it. And incidentally, if you study Wallace’s essay carefully, you see differences from Darwin. Wallace, for instance, denied the pertinence of artificial selection. Wallace never had the term “natural selection.” Wallace had inclinations to group selection in a way absent from the Origin or earlier writings. This is not to belittle Wallace. Not at all! But he was not Charles Darwin.

The claims of others can be dismissed as well. Before Darwin, there were several people who had thoughts of natural selection and we know that he read some of them. For instance, in a pamphlet by the breeder John Sebright, there is an explicit reference to the force of natural selection, a reference that stimulated Darwin to underline the words and make a comment in the margin (Ruse, 1975a). But there is no real question that these people sparked full evolutionary thoughts in Darwin, and generally the last thing they wanted to do was use natural selection to promote evolution. Edward Blyth (1835), with whom Darwin was to have very cordial and helpful correspondence (he actually drew Darwin’s attention to an important earlier essay by Wallace) explicitly denied that his thinking had evolutionary implications. And as far as others were concerned, preDarwinian (that is pre- Origin ) evolutionists in particular, they certainly had effects on general opinion, but not like Darwin. Chambers’s Vestiges undoubtedly took the sting out of evolution, so by the time that Darwin published, it was to a certain extent old hat, but it did not have the effect of the Origin . The same is true of others, like Herbert Spencer. For all that Spencer (1852), too, hit on the idea of selection, he always thought that Lamarckism is the chief cause of evolutionary change, and while his thinking did influence some, including his big friend Thomas Henry Huxley, he likewise did not swing people in the way that the Origin did.

Having said all of this, however, there are some interesting questions about the extent to which the revolution was truly Darwinian. Clearly some nuanced thinking is needed, starting with the fact that there was 150 years of evolutionary thinking before Darwin, including speculations by his own grandfather Erasmus Darwin. Toward a fuller analysis, divide the history of evolutionary thinking into 3 periods (Ruse, 1996). The first period, from the early 18th century (the time of the French encyclopediast and early evolutionist Denis Diderot) to the publication of the Origin in 1859, was the time when the status of evolutionary thinking was that of a pseudo science: an emergent on the cultural value of progress. Second, from the Origin to the full incorporation of Mendelism into evolutionary thinking, say ≈1930 with the work of Ronald Fisher, J. B. S. Haldane, and Sewall Wright, evolution had the status of a popular science. There was some professional work going on, particularly in the area of phylogeny tracing, but generally evolution was a museum science, still a vehicle for thoughts of progress. Causal thinking was second-rate or (often) absent entirely. Top-quality work in biology was increasingly by young researchers who turned from phylogeny tracing to microscope-based sciences, especially cytology, and then on to genetics in the 20th century. Finally, from 1930 to the present we have a fully professional science of evolutionary biology. We entered the era of neo-Darwinism (as it was called in Britain) or the synthetic theory of evolution (as it was called in the United States).

Now, frame the discussion against the background of this 3-fold division of history. If we consider the revolution in a broad sense, from the beginning of the 18th century to the beginning of the 21st century, there are 2 major points at which we want to say that it is a Darwinian revolution. The first was in the transition from being a pseudo science to being a popular science. Before the Origin , the evidence for evolution just was not there. If you believed in evolution, you were fueled primarily by ideological reasons. It is true that people knew about homologies, the fossil record was starting to fill out, embryology was suggestive, and so forth. But the full picture was not there. After the Origin , being an evolutionist was just plain common sense. And people did become evolutionists. Even church people. With the notable exception of American evangelicals, especially in the South, evolution was accepted (Roberts, 1988). It is true that there was some backsliding, in the Catholic Church especially by century’s end, but overall people became evolutionists (Artigas et al., 2006).

This change was thanks to Darwin, especially to the structure of the argument in the Origin . The methodologists of science of the day, more particularly, the methodologists of science of the 1830s when Darwin was discovering and formulating his theory, insisted that the best science has at its heart a true cause, a vera causa . They differed over what is the mark of a vera causa . John F. W. Herschel (1830), with empiricist leanings, insisted that we have direct sensory evidence or something analogical. We know that a force pulls the moon toward the Earth because swinging a stone around on a piece of string requires you to pull the stone in toward you. William Whewell (1837, 1840), with rationalist leanings, insisted that we justify the acceptance of our hypothesis through its implying a whole range of empirical evidence, thus manifesting what Whewell called a “consilience of inductions.” As in a court of law, where the guilt is ascribed through the wide range of clues that it explains, Darwin set about satisfying both vera causa criteria (Ruse, 1975b). First, he argued analogically from artificial selection (the work and triumphs of the animal and plant breeders) to natural selection, from something known and seen to something not known and seen. Then he turned around, and showed how evolution through selection throws light on topics across biology, instinct, paleontology, biogeography, systematics, anatomy, embryology, and more. As evolution through selection explains, so conversely the explained areas justify our faith in evolution through selection.

There are questions about how effective was the appeal to artificial selection. Generally before the Origin it was taken as a reason not to believe in ongoing change (no one has turned a horse into a cow) and I have mentioned how Wallace denied explicitly that it was relevant to the evolution issue. After the Origin , people like Huxley took the failure to create new species artificially as a reason to hesitate before full acceptance of natural selection’s powers. However, undoubtedly at some level the analogy softened people up to evolution. Part of Darwin’s genius was always to put his ideas into comfortable contexts. He argued to natural selection via the struggle for existence, which was something that came out of the thinking of the Reverend Thomas Robert Malthus (1826), who pointed out that population demands will always outstrip potential gains in space and food. Everyone knew about these Malthusian calculations, and, even if they did not much like them, generally they accepted the conclusions. Likewise with the world of breeders, people at least took some comfort from the arguments provided by Darwin, even if they were not definitive.

The consilience was a different matter. Here, Darwin did persuade. At least, he persuaded to a point. As noted, evolution after the Origin was nigh a truism. The mechanism was another matter. No one denied natural selection. Very few accepted that it could be as powerful as Darwin suggested. People became evolutionists in droves. The number of pure Darwinians, as we might term selectionists, was very few, and the most prominent after Darwin himself, namely Wallace (1870), became enamored of spiritualism in the 1860s and he started to deny selection when it came to humans. The reasons for this halfway acceptance are well known. On one side, there were scientific problems with selection. It was thought that it could never be strong enough to overcome the supposed averaging nature of heredity. Even the best new variations would be swamped into nonbeing in a generation or two (Greg, 1868). Added to this the physicists (ignorant as they were of the warming effects of radioactive decay) denied that there was time enough for such a leisurely process as natural selection (Burchfield, 1975). On the other side, there was the matter of adaptation. Selection does not just bring about change. It brings about adaptive change. This ran into trouble from folk at both ends of the spectrum. German-influenced biologists like Huxley (1884) thought that adaptation is but a minor phenomenon, and hence felt no need to embrace selection on that score. Nonadaptive saltations (jumps, what we today would call “macromutations”) would do the job for evolution. Heavily Christian evolutionists like American botanist Asa Gray (1876) thought that selection could not fully explain adaptation and so they wanted (God-) directed variations. As Darwin said, this rather made natural selection redundant.

So after 1859, it was evolution yes; natural selection, much less so. This meant that the dream that Darwin had had of founding a professional science of evolutionary studies, based on natural selection, never really got off the ground. There certainly was professional evolutionism, particularly that around the German biologist Ernst Haeckel (1866). But, increasingly, a lot of what was produced lost touch with reality as fantabulous tales were spun using the unreliable biogenetic law, ontogeny recapitulates phylogeny. In Britain you had the incredible paradox that the chief post- Origin evolutionist in the second half of the 19th century, a man deeply involved in and highly influential on postsecondary education, Thomas Henry Huxley, never taught evolution to his students. He thought they should concentrate on physiology and morphology (Ruse, 1996).

So evolution became the subject of the popular lecture hall, working men’s clubs, and the public-friendly British Association for the Advancement of Science, and the leading evolutionists moved from the universities to the museums. Huxley student E. Ray Lankester ran the British Museum (Natural History) in London and Huxley student Henry Fairfield Osborn ran the American Museum of Natural History in New York. And what you want in museums are displays, with an educational and cultural message. So this is what was supplied. Terrific displays of fossils, especially of all of those dinosaurs now being discovered and brought back from the American West, and all put in a progressive fashion to demonstrate that life may have started as blobs but that it ends as humans, especially white humans.

Finally, ≈1930 came the move from popular science to professional science. First there were the mathematicians, the population geneticists mentioned above. Then came the empiricists, the experimenters, and naturalists, who put flesh on the mathematical bones: E. B. Ford and his school in Britain and Theodosius Dobzhansky and his fellow evolutionists in the United States. Now we had university posts, researchers, graduate students and grants, journals, societies, and everything else we associate with professional science, and not just at the sociological level, because the work produced was firmly based on empirical studies with mathematical models doing the explaining. The epistemic virtues of science (consistency, coherence, predictability, fertility, simplicity) were taken seriously and the worth of work was judged by its success against these virtues. And right at the heart was natural selection, which continues to this day. Here, again then Darwin has made a major contribution to evolutionary studies.

• WAS THERE A DARWINIAN REVOLUTION? METAPHYSICS

What of the Darwinian revolution in the broader sense, the side dealing with our metaphysical view of ourselves, our place in nature? Here, Darwin was crucially important if not completely successful. He himself was stone-cold certain that we humans are part of the world of nature. His experience with the native people from the bottom of South America, the Tierra del Fuegians, had convinced him of that (Darwin, 1969). And he made his case publicly, as is well known, not in the Origin (which was somewhat reticent on the human question) but in the Descent of Man , published some 12 years later (Darwin, 1871). However, now we must ask what it means to put ourselves in nature. There are 3 possible answers. First, it can simply be to make humans part of the natural order of things. We are ruled by the laws of physics and chemistry and biology and so forth just like anything else. Second, it can be showing that natural selection was the chief causal force making us what we are, and perhaps that selection is still significant. Third, it can be to claim that we are no different from anything else, at least in value or worth. An oak tree, a wart hog, a human, ontologically and axiologically they are the same.

If you are thinking of the first of these claims, if you think of the Darwinian revolution as an attempt to make humans entirely natural, in the sense of produced and working according to the same laws of nature as everyone else, one can truly say that for many people this revolution has succeeded and Darwin played a major role in its success. The Origin put us firmly in the natural picture and then following up the Descent of Man was a major analysis of humankind from a naturalistic perspective, cover ing not just our physical frames but also our moral beliefs and social and intellectual natures generally. No one would want to say that it was Darwin alone. Huxley and his Man’s Place in Nature (1863) was a key figure back then and of course there have been literally hundreds of other contributors, in and out of biology, since. But Darwin deserves his name up there. Even those who may not much care for the work actually being produced seem to agree that the naturalistic program is the right one and that it must take evolution into account. Although having said this, it must be admitted that there are many for whom this program is unacceptable, and who would deny that Darwin has succeeded or indeed could succeed. The official Catholic position, for instance, is that we have souls and these are created and inserted miraculously into human frames, actually, human zygotes (John Paul II, 1997). And this obviously is but one end of the spectrum that goes all of the way, through the kind of directed evolution allowed by some members of the intelligent design theorists (Behe, 1996), across to the hard-line young earth creationists who think that humans were created miraculously on the sixth day (Whitcomb and Morris, 1961).

Second, what about natural selection? Again, Darwin is very important, perhaps indeed more important than just the naturalism part. The Descent of Man showed in detail how natural selection (combined with sexual selection) is a crucial explanatory factor behind much that we think of as human, physical, and social. This is a path that many have followed, most notably in recent times by Harvard biologist Edward O. Wilson in his On Human Nature (1978) , a work that covers morality, religion, conflict, and much more. Wilson is not a hard-line evolutionary determinist, but he does argue that (in his language) the twig is bent. The human mind is not a tabula rasa but shaped by the forces of natural selection. And many workers in the evolutionary field today would agree, from physical anthropologists through human behavioral ecologists and on to evolutionary psychologists.

However, 2 reservations must be expressed. First, much that has been claimed in the name of Darwinian selection bears but a passing resemblance to the program of the Descent . Historically, one thinks of social Darwinism, a movement that covered many different ideologies and that generally owed more to Herbert Spencer than to Charles Darwin (Ruse, 2000). When, to take a particularly egregious example, German general Friedrich von Bernhardi (1912) claimed that Darwin showed that might is right and that the Motherland has almost an obligation to seize from its neighbors, he owed little to the old evolutionist who had worked away in his study in the English countryside. One might as much credit Plato because the doctrine more closely resembled the thinking of Thrasymachus in the Republic . Today one has similar divisions. For instance, philosopher Peter Singer (2000) has claimed the authority of Darwin for an explicitly left-wing manifesto. Philosopher Larry Arnhart (2005) has no less enthusiastically claimed Darwin’s support for a right-wing view of society.

Second, it must be appreciated that (apart from those who reject the naturalistic program in itself) there are those who argue that natural selection is not the appropriate tool to analyze human nature. Clearly a lot of social scientists think this, but so also do prominent biologists. The Harvard geneticist Richard Lewontin, a committed Marxist, is one who denies that evolutionary biology is the key to understanding Homo sapiens . He opts rather for economic and like forces (Levins and Lewontin, 1985). It may well be that the late Stephen Jay Gould shared his sentiments. With some few exceptions, notably Elliott Sober (1981) who has not only argued for the influence of selection on our modes of thinking in the realm of science but who has also coauthored a spirited defense of the selection-based nature of human morality (Sober and Wilson, 1997), the philosophical community feels negatively inclined to the selection-explains-humans program. The particulars are thought wrong; feminist philosopher Lisa Lloyd (2005) launched a heavy attack on the putative biological basis of the human female orgasm. But more importantly the overall program is declared ideological and inadequate. Even those who think there might be a possibility of a selection-based approach to human nature declare regretfully that the quality of the work produced thus far falls far short of the standards of adequate science (Buller, 2005; Richardson, 2007).

We come to the third claim, namely that we humans are not in any way special. You might think that proving this was Darwin’s intent; after all, he did caution himself never to use the terms “higher” and “lower” (writing this on the flyleaf of his copy of Vestiges ) and the mechanism of natural selection is nothing if not egalitarian. What is it better to be, the AIDS virus or a lowland gorilla? Speaking purely biologically, there are few who would speak up for the ape. However, it cannot be gainsaid that if this was indeed the intent of the Darwinian revolution it would have been news to Darwin himself. He always thought of humans as being at the top of the tree of life and European humans as being on the highest branches of all (Richards, 1992; Ruse, 1996). Indeed, in later editions of the Origin he added material suggesting that natural selection leads to progress and ultimately to intelligence. He invoked what today’s evolutionists call “arms races” where lines compete against each other, improving adaptations in the process, and argued that eventually this would lead to intelligence and progress.

If we take as the standard of high organisation, the amount of differentiation and specialization of the several organs in each being when adult (and this will include the advancement of the brain for intellectual purposes), natural selection clearly leads toward this standard: for all physiologists admit that the specialization of organs, inasmuch as in this state they perform their functions better, is an advantage to each being; and hence the accumulation of variations tending toward specialisation is within the scope of natural selection.

Peckham (1959)

Although most of Darwin’s contemporaries did not rely on selection, they, too, virtually automatically assumed that evolution was progressive, with humans at the top. One possible exception was the older Thomas Henry Huxley who in 1893, 2 years before his death, argued that evolution is not progressive and that if we are to succeed morally we must conquer the evolved beast within (Huxley, 1893). Perhaps even he thought we are special; it is just that we must use our evolved moral senses and intelligence to claim our rightful places at the top.

Where do we stand today? Few actual working scientists are going to make any such claims, especially not in their science. The exceptions, people like the Cambridge paleontologist Simon Conway Morris (2003) who argues that there are niches and that organisms seek them out and occupy them and that at the topic is the intelligence-cultural niche that we humans uniquely have found, tend to keep such speculations for books that are aimed at the general audience. Moreover, there are those, Stephen Jay Gould (1988, 1989) was a leader in this respect, who would say that there is no progress and that the Darwinian revolution shows that there cannot be. Ultimately, natural selection is not a progress-producing mechanism. So we could say that the Darwinian revolution does prove the nonspecial status of humans, and finally today people recognize the fact. However, this may not be the entire truth. A case can be made for saying that still today the popular perception is of progress leading to humans. That was Gould’s lament. Surveys suggest that this is what schoolteachers, even those favorable to evolution, tend to teach to their students (Zimmerman, 1987). And museums as often as not give the same impression. Go to the Museum d’Histoire Naturelle in Paris and find that the display starts with blobs and ends with you yourself on television. If you are in any doubt as to the message, the floor above has a display of technology from the crudest beginnings to the sophisticated forms that we have today.

Summing up: Darwin played a major role in moving us to a naturalistic view of human nature, although there are those (generally if not always working from a religious perspective) who would deny that this can ever be done completely and successfully. Darwin played no less (and perhaps more of) a role in convincing people that natural selection is the key causal factor in molding and perhaps today controlling human nature, although one should be wary of all that is claimed in his name and now there are many more critics (not necessarily religious) who are uncomfortable with this program and would reject it in part or in whole. One can make an argument that Darwin paved the way for a view of humankind that gives us no special status here on this earth, although this was certainly not Darwin’s own aim and, especially in the public domain, beliefs privileging humans persist today.

• WAS THERE A DARWINIAN REVOLUTION ?

Finally, how does one analyze conceptually what happened because of the Origin of Species ? Let us start with 2 basic theories of theory change. On one hand, we have the fairly traditional view, represented by the logical empiricists like Ernest Nagel (1961) and Carl Hempel (1966). This view tends to stress continuity, with moves made driven by the evidence and reason. To a certain extent, there will be replacement of old theories by newer, truer theories. Something like this happened when Copernicus knocked out Ptolemy. But there will probably be continuity. There was in the Copernican case. It was the same world that the two were describing: the same earth, the same sun, the same moon, the same planets, the same stars. Both sides agreed that circular motion must be preserved. Both sides used epicycles and deferents. It is true that almost all of this was changed as the years went on, but the growth of science was evolutionary not revolutionary. You can have revolutions, but they are gradual, not abrupt, and important is the notion of reduction, when one theory is absorbed in another, or more accurately when one theory can be shown the special consequence of another theory. Supposedly the macroscopic understanding of gases (Boyle’s law and so forth) could be shown a special instance of the kinetic theory of gases.

On the other hand, we have the revolutionary view of Thomas Kuhn (1962). Here, the change is abrupt. In Kuhn’s terminology we go from one paradigm to another, and there is no continuity. Hence, the change of viewpoint, from one paradigm to another, can never be fueled by reason. It always has to be more of a conversion experience. This is the reason there is often such bitter fighting between scientists. There is no common or shared set of beliefs that can be decisive. As with political disputes, everyone argues from within their own system.

Without wanting to homogenize everything into a gray blandness, it is probable that both positions have things to say that throw light on Darwin and his achievements. Clearly, as the logical empiricists would lead one to expect, in some respects Darwin was replacing old positions with new ones. If you think for instance of Darwin’s old friend and mentor, the violently antievolutionist, Cambridge paleontologist Adam Sedgwick (1850), Darwin is simply saying that Sedgwick’s reading of the fossil record is wrong. Sedgwick argues that there are and always will be gaps in the record and that these represent real breaks in the continuity. Darwin is saying that the gaps are artifacts of incomplete fossilization and that there were bridging organisms, even if we never find them, although that should never stop us in the pursuit of such links. An analogous argument holds for the problem of the pre-Cambrian period. At the time of the Origin , there were no organisms at all from this period and their absence was rightly taken as a major problem for Darwin’s theory. The earliest organisms of all, like trilobites, were highly complex and sophisticated invertebrates. How could they have just arrived on the scene? Sedgwick said simply that there were no pre-Cambrian organisms. Darwin said that they had existed. Two conflicting views and as Darwin’s overall theory was accepted, Sedgwick was pushed out. Today we have many such organisms, and we know that Darwin was right (Knoll, 2003). We had a simple case of one theory being right and the other wrong, and the right one pushing out the wrong one.

What about reduction? One does not see any cases of whole positions being taken up by Darwin’s theory, but if you look at the range of other pre- Origin positions, talk of reduction does not seem entirely inappropriate. Think of the position of someone like Richard Owen, deeply influenced by the Naturphilosophen . In a work like On the Nature of Limbs (Owen, 1849), it is hard to say if he is actually endorsing evolution; the answer is that he probably was but that he wanted to be sufficiently ambiguous to escape the critics. (Even as it was, Sedgwick was highly suspicious.) More importantly, although Owen certainly does not deny adaptation, he stresses homology in a very big way. Now when Darwin comes along with the Origin , he is certainly not going to stress homology over all other things as did Owen, but he is not going to deny it either. Most interestingly, he argues that it follows as a consequence of evolution through natural selection.

It is generally acknowledged that all organic beings have been formed on two great laws: unity of type and the conditions of existence. By unity of type is meant that fundamental agreement in structure, which we see in organic beings of the same class and which is quite independent of their habits of life. On my theory, unity of type is explained by unity of descent. The expression of conditions of existence, so often insisted on by the illustrious Cuvier, is fully embraced by the principle of natural selection. For natural selection acts by either now adapting the varying parts of each being to its organic and inorganic conditions of life; or by having adapted them during long-past periods of time: the adaptations being aided in some cases by use and disuse, being slightly affected by the direct action of the external conditions of life, and being in all cases subjected to the several laws of growth. Hence, in fact, the law of the conditions of existence is the higher law; as it includes, through the inheritance of former adaptations, that of unity of type.

Darwin (1859)

This is what theory reduction is all about. Darwin would not have accepted every aspect of Owen’s thinking. But there was continuity, with older ideas being absorbed into newer ones, and this is an important thing to note about Darwin and his work and his importance.

Now let us express some sympathy for the Kuhnian view. Take the question of homology and pick up on the point where Darwin and his supporters would break with Owen. Huxley (1857–1859) brings out this opposition in his Croonian lecture on the vertebrate skull, given at the Royal Society the year before the Origin appeared. He faulted Owen for being an idealist rather than a naturalist, claiming (correctly) that for Owen the archetype represents a divine platonic pattern rather than something produced purely by mechanical laws. As it happens, he also claimed correctly that this led Owen to see more than was justified, namely that the skull is made from transformed vertebrae, a claim that Darwin had accepted and that he dropped smartly before the Origin appeared. The point is that, evolutionist or not, Owen did have a vision of the world that was fundamentally different from that of Darwin. And it persisted after the Origin , as he tied himself in knots over the hippocampus, present or not in humans and apes (Rupke, 1994). It was not the facts as such that counted, but different visions of reality.

So in this sense, we do have something Kuhnian going on, different paradigms if you will. But note that it is not just a question of evolution or not evolution, and certainly not of selection or not selection. Nor is it simply a matter of biblical literalism. There were literalists, increasingly in the American South, but by and large this is not an issue in the debate around the Origin . Literalism had more to do with a defense of slavery than with the interpretation of fossils (Noll, 2002; Ruse, 2005). The big religious critics like Sedgwick and Bishop Wilberforce all accepted an old earth and a lot more. It is rather “man’s place in nature” that was at stake. Owen was on one side. So was Sedgwick. Darwin’s great American supporter Asa Gray was on this side, too, a point that Darwin saw, when he grumbled that Gray’s appeal to directed variations took the discussion out of the realm of science. And we could include more, especially Darwin’s old friend, the geologist Charles Lyell, who staggered across the evolutionary line but bitterly regretted having “to go the whole orang” (Wilson, 1970). On the other side, we have Darwin and Huxley (for all that the latter downplayed the significance of selection). And also there was Joseph Hooker, the botanist, and increasingly a host of younger workers who did not depend on church appointments for their incomes and who wanted to work and think in a secular fashion.

And in confirmation of Kuhn, this is where we tend to get the nastiness: Sedgwick (1860a,b) writing irate letters to the newspaper about Darwin’s methodology; Bishop Wilberforce (Huxley, 1900) sneering at Huxley’s ancestry; Owen (1860) doing everything he could to give the Darwinians a bad name; and so forth. There were certainly vigorous debates about the science, but rarely did the science itself cause unpleasantness. It was always (as in the Huxley-Owen squabble over the brain) in the cause of the bigger metaphysical picture. Very instructive is the age-of-the-earth question. Physicist William Thompson (later Lord Kelvin) did not much like Darwin’s naturalistic approach to humankind, but he objected publicly to the long time span that Darwin needed. As it happens, Thompson’s research assistant was none other than George Darwin, Charles Darwin’s mathematically gifted son. So Charles Darwin was not allowed to forget or escape the problem. However, even though in the end they simply had to disagree, neither Charles Darwin nor Kelvin thought that the disagreement was personal or ideological. It was just not that sort of difference (Burchfield, 1974). So in the sense that there were differences of that sort, differences where because of rival metaphysical views people talked past each other, one could claim that the Darwinian revolution was Kuhnian.

There is another way in which Kuhn’s thinking is insightful. A paradigm is a world picture, within which a scientist works, that gives him or her tasks for the future, and which seems obvious or certain in some sense. Obvious or certain in the sense that (as just noted) you cannot see the point of view of others not in the paradigm (Ruse, 1999). Think again of the divide in biology between formalism and functionalism and put it in a broader historical context. As Aristotle pointed out, on one hand we have the adaptive side to organisms, what he called final causes, meaning that the parts function for the benefit of the whole. On the other hand, we have homologies (isomorphisms) where the parts may well be used for different ends. Down through the ages people have continued to note these 2 sides to organisms, and interestingly people tend not to be ecumenical on the matter. Like Darwin, they are partisans for one side or the other. Either they opt for function with form secondary or form with function secondary. What is fascinating is the way that this divide goes right across the Darwinian revolution. At the beginning of the 19th century one had formalists who did not accept evolution, many of the Naturphilosophen for instance. The philosopher Hegel (1817) is a case in point. One also had functionalists who did not accept evolution. The great French comparative anatomist Georges Cuvier (1817), with his theory about the conditions of existence (that he explicitly tied to final-cause thinking), was one such person. Then at the time of the Origin we have people who crossed the evolutionary divide who were one or the other, but not both. Darwin was a hard-line functionalist. That is the whole point of natural selection. Huxley equally was a hard-line formalist (Huxley and Martin, 1875). That’s why he could not see much need of natural selection. Today, the differences persist. Take the 2 great popularizers of evolution, Englishman Richard Dawkins and American Stephen Jay Gould. Dawkins (1976, 1986) is and always has been an ardent functionalist. For him, it is adaptation all of the way and the only problem really worth solving. He thinks natural selection is a universal law of nature. Gould (1977b, 1989, 2002) was notoriously ambivalent about natural selection and function, thinking it a holdover from English natural theology, and he again and again stressed form. This was the central message of his famous paper on spandrels, cowritten with geneticist Richard Lewontin (Gould and Lewontin, 1979).

I would argue that in a real sense we have Kuhnian paradigm differences operating here. Different visions, unable to bridge the gap (Ruse, 2003). I find it interesting that metaphors are involved, things that Kuhn stresses as being important in paradigm thinking. We have the organic world as a human artifact. [See Darwin’s use of this metaphor in the little post- Origin book on orchids (Darwin, 1862).] We also have the organic world as a snowflake [Kant’s 1790 picture (Kant, 1951)] or as a crystal [used by Whewell (2001)]. Admittedly, this sense of paradigm does not fit exactly with the senses of paradigm found in the Structure of Scientific Revolutions . For a start, both sides do recognize some of the merits of the other side. It is hard to think that the ontologies are completely different. For a second, with respect to the same things 2 people could be in and out of different paradigms. With respect to homology, Owen and Huxley were divided over the idealistic/naturalistic issues, and yet with respect to thinking that homology more important than function, they were together. Third, perhaps most importantly, the 2 paradigms (without prejudice, let us call them this) persist, down through the ages. It is not a matter of one beating out the other. It is true that today functionalism has the upper hand, but things could change. In fact, in the past 20 years things have moved, with evolutionary development enthusiasts coming onside in a very strong way for formalism. The homologies they find, for instance between humans’ and fruitflies’ genetic sequences, strike them as absolutely fundamental and calling for a total revision of evolutionary thinking.

The homologies of process within morphogenetic fields provide some of the best evidence for evolution, just as skeletal and organ homologies did earlier. Thus, the evidence for evolution is better than ever. The role of natural selection in evolution, however, is seen to play less an important role. It is merely a filter for unsuccessful morphologies generated by development. Population genetics is destined to change if it is not to become as irrelevant to evolution as Newtonian mechanics is to contemporary physics.

Gilbert et al. (1996)

We shall have to see how this all pans out. An ardent Darwinian like me is less than overwhelmed (Ruse, 2006, 2008). But then I am an ardent functionalist, so I am proof of the point I am making about the divide. Obviously, the ideas do persist and not just as fossils.

If the point being made now is well taken, then perhaps Hodge was right all along. There was no Darwinian revolution. The paradigms of form and function went in before Darwin and came out after Darwin. This taken as a general conclusion is obviously false. Because of Darwin and the Origin of Species , major things did happen in biological science. Less paradoxically, let us say that a complex phenomenon like the Darwinian revolution demands many levels of understanding. Blunt instruments will fail us as we try to understand scientific change. It is necessary to tease strands apart and consider them individually as we try to understand and to assess what is going on.

There are other controversies (unmentioned thus far here) very active today. Often these involve not just the events directly around Darwin but aspects of the broader picture. Robert J. Richards (who has been noted as a major contributor to the history of evolutionary biology) argues that the post-Darwinian period, especially that influenced by the German evolutionist Ernst Haeckel, was much more pure-Darwinian than people have recognized. He thinks that Darwin was deeply Romantic in his thinking, influenced by the currents that came from Germany at the beginning of the 19th century, and that after the Origin people like Haeckel were simply responding to and building on that which was already there (Bowler, 1976; Richards, 2002). Other students of the period (including myself) disagree strongly, thinking that (as Karl Marx noted) Darwin was quintessentially English in his thinking and that it is right to see Haeckel as responding to non-Darwinian themes, an attitude that inflected evolutionary biology until the synthesis of the 1930s (Ruse, 2004). Another controversy centers on the work and interpretations of Peter J. Bowler (also noted above as a major contributor). He agrees that post-Darwinian thought was deeply non-Darwinian, but he nevertheless thinks that it was good-quality science and that it fed smoothly into the synthesis. Indeed the latter would not have occurred without the former (Bowler, 1988, 1996). Others, again including me, disagree strongly, arguing that post-Darwinian evolutionary biology was often really poor-quality science (notoriously following Haeckel in spinning unsustainable analogies between embryology, ontogeny, and paleontology, phylogeny) and that the synthesizers of the 1930s had to cleanse the Augean stables and return to the thinking of the Origin (melded admittedly with the new genetics) before further advance was possible (Ruse, 1996).

These controversies, however, must be the topic of another essay. Here, I rest confident that I have shown why, for a philosopher and historian of science, analyzing the Darwinian revolution is such a worthwhile challenge.

• Cite this Page National Academy of Sciences (US); Avise JC, Ayala FJ, editors. In the Light of Evolution: Volume III: Two Centuries of Darwin. Washington (DC): National Academies Press (US); 2009. 14, The Darwinian Revolution: Rethinking Its Meaning and Significance.
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The Evolution of Charles Darwin

A creationist when he visited the Galápagos Islands, Darwin grasped the significance of the unique wildlife he found there only after he returned to London

Frank J. Sulloway

From the nine times I have made the 5,000-mile journey to the Galápagos Islands, to follow in Charles Darwin’s footsteps, the most enduring impression I have gained is of life’s fragility. The minute a person steps off any of the tourist trails created by the Galápagos National Park Service and heads into the untamed interior of one of these islands, there is the risk of death under the intense, equatorial sun. On Santa Cruz Island, where the Charles Darwin Research Station is located, 17 people have disappeared since 1990. Most were subsequently found alive after having become hopelessly lost in dense underbrush and rugged volcanic terrain. But some perished. One was a young Israeli tourist who lost his way in Santa Cruz’s Tortoise Reserve in 1991. Amassive, two-month search failed to find him. In fact, some of the searchers themselves became lost and had to be rescued. In the end, fishermen discovered the young man’s body. A former Israeli tank commander, he had been in top physical condition, yet had managed to go only six miles before succumbing to the searing heat and lack of fresh water. A sign in the Tortoise Reserve says bluntly: “Stop. Do not go beyond this point. You could die.”

This is the deceptively treacherous world of sun-baked lava, spiny cactus and tangled brushwood into which Charles Darwin stepped in September 1835, when he reached the Galápagos Islands with fellow crew members of the HMS Beagle. The Beagle’s captain, Robert FitzRoy, described the barren volcanic landscape as “a shore fit for Pandemonium.” At 26, Darwin had come to the archipelago, which straddles the Equator some 600 miles west of Ecuador, as part of the Beagle’s five-year mission to survey the coast of South America and to conduct a series of longitudinal measurements around the globe. Darwin’s five-week visit to these remarkable islands catalyzed the scientific revolution that now bears his name.

Darwin’s revolutionary theory was that new species arise naturally, by a process of evolution, rather than having been created—forever immutable—by God. According to the well-established creationist theory of Darwin’s day, the exquisite adaptations of many species—such as the hinges of the bivalve shell and the wings and plumes on seeds dispersed by air—were compelling evidence that a “designer” had created each species for its intended place in the economy of nature. Darwin had wholeheartedly accepted this theory, which was bolstered by the biblical account in Genesis, until his experiences in the Galápagos Islands began to undermine this way of thinking about the biological world.

The Galápagos Islands were formed by volcanic eruptions in the recent geological past (the oldest of the islands emerged from the ocean just three million years ago), and Darwin realized that the remote setting must have presented life with a new beginning. “Seeing every height crowned with its crater, and the boundaries of most of the lava-streams still distinct, we are led to believe that within a period, geologically recent, the unbroken ocean was here spread out,” he wrote in his Journal of Researches. “Hence, both in space and time, we seem to be brought somewhat near to that great fact—that mystery of mysteries—the first appearance of new beings on this earth.”

How, Darwin asked himself, had life first come to these islands? “The natural history of these islands,” he later pointed out, “is eminently curious, and well deserves attention. Most of the organic productions are aboriginal creations, found nowhere else.” Yet all of the creatures showed a marked relationship with those from the American continent. The novel Galápagos species, Darwin reasoned, must have started out as accidental colonists from Central and South America and then diverged from their ancestral stocks after arriving in the Galápagos. As he traveled from island to island, Darwin also encountered tantalizing evidence suggesting that evolution was proceeding independently on each island, producing what appeared to be new species.

Other evidence, from the South American continent, showed that species did not seem to be stable across either geographic space or the deep reaches of paleontological time. But the particularly compelling evidence from the Galápagos Islands catapulted Darwin and life science into the modern age. He subsequently added to his daring endorsement of evolution the crucial insight that species evolve by means of natural selection: variants that are better adapted to their environments are more likely to survive and reproduce. When he finally published On the Origin of Species by Means of Natural Selection in 1859, Darwin’s revolutionary theories not only recast the study of life but also turned the Galápagos Islands into hallowed scientific ground.

More than three decades ago, I became fascinated by Darwin’s life, and especially by his historic voyage around the world. When evolutionary biologist Edward O. Wilson, whose undergraduate course I was taking at Harvard, learned of my interest, he suggested that I go to the Galápagos Islands, and he helped fund a documentary about Darwin’s voyage. My first trip, in 1968, was two years before the beginning of organized tourism in the Galápagos. Just getting to the islands was a challenge. Our expedition flew from Guayaquil, Ecuador, in a PBY, an amphibious, twin-engine patrol plane dating back to the World War II era. We sat in seats made of mesh nets. There were numerous holes in the plane’s undercarriage, through which I could see all the way to the ocean below. The impression these starkly beautiful islands made upon me was indelible (the volcano that forms the island of Fernandina put on a spectacular eruption during our visit).

Eight expeditions later, I continue to be drawn to these islands in an effort to document their extraordinary impact on Darwin, as well as to study ecological changes since Darwin’s day. With the advent of organized tourism, much has changed. Now, two to four passenger planes fly each day to the Galápagos, bringing a total of about 100,000 tourists a year. Puerto Ayora, home to the Charles Darwin Research Station, is a booming tourist stop with a population of about 15,000 people, almost ten times the number that resided there during my first visit. As tourists enjoy their organized cruises around the islands, they are confined to 60 localities, carefully selected by the National Park Service, and are required to stay on clearly marked paths that keep them out of harm’s way.

Two main questions confront the student of Darwin’s historic visit: Where did Darwin go, and exactly how did his visit affect his scientific thinking? Answering the first turns out to be easier than one might think, thanks to a rich repository of documentary sources. The British Navy had a penchant for keeping detailed records, and the Beagle’s voyage is described in three ship’s logs, Captain FitzRoy’s personal narrative, a series of excellent maps made by the Beagle’s officers, and various watercolors and sketches by crew members. We are also able to draw on Darwin’s own extensive record of his dozen or so field trips, which encompasses more than 100 pages of unpublished notes and more than 80 pages of published material.

For five years the Beagle’s logs recorded, often on an hourly basis, where the ship was and what it was doing. Two days after the first sighting of land in the Galápagos, on September 15, 1835, the Beagle anchored in Stephens Bay on Chatham Island, now known as San Cristóbal. (All the islands were given Spanish as well as English names by their early visitors, who included Spaniards seeking Inca gold and silver in Peru, and British buccaneers intent on stealing these riches from the Spanish.) From this anchorage, the Beagle officers recorded a bearing of N10ºE to Kicker Rock, an impressive 470-foot islet about four miles off the shore, and a bearing of N45ºE to Finger Hill, a 516-foot tuff crater. When drawn on a map, the place at which these two bearings cross indicates the Beagle’s point of anchorage. Using other bearings in the Beagle’s logs, together with Darwin’s remarks in his diary and scientific notes, it is possible to reconstruct virtually all of Darwin’s landing sites and inland treks during his five-week visit. These include many regions that are either in remote or potentially dangerous locations and hence off limits to tourists.

As the Beagle sailed from east to west through the archipelago, Darwin visited four of the larger islands, where he landed at nine different sites. On San Cristóbal, Darwin was particularly drawn to a heavily “Craterized district” on the rugged, northeastern coast. “The entire surface of this part of the island,” Darwin reported, “seems to have been permeated, like a sieve, by the subterranean vapours: here and there the lava, whilst soft, has been blown into great bubbles; and on other parts, the tops of caverns similarly formed have fallen in, leaving circular pits with steep sides. From the regular form of the many craters, they gave to the country an artificial appearance, which vividly reminded me of those parts of Staffordshire, where the great iron-foundries are most numerous.”

As Darwin explored San Cristóbal, he encountered many birds and animals new to him. He marveled at the remarkable tameness of the birds, pushing a curious hawk off a branch with the barrel of his gun, and trying to catch small birds with his hands or in his cap. He also noted the striking dominance of reptiles within these islands, which made the archipelago seem like a journey back in time. On the shoreline were swarms of “hideous-looking” marine iguanas—the world’s only oceangoing lizards. On land, the Beagle crew encountered large land iguanas, closely allied to their marine cousin; a couple of smaller lizards; a snake; and giant land tortoises, after which the islands are named. (The old Spanish word galápago means saddle, which the shape of the tortoise’s carapace resembles.)

In the midst of a partly vegetated lava field on San Cristóbal, Darwin came upon two enormous tortoises, each weighing more than 200 pounds. One, he noted, “was eating a piece of cactus, and as I approached it, it stared at me and slowly stalked away; the other gave a deep hiss, and drew in its head. These huge reptiles, surrounded by the black lava, the leafless shrubs, and large cacti, seemed to my fancy like some antediluvian animals.” Altogether these giant reptiles contributed dramatically, Darwin thought, to the “strange Cyclopean scene.”

Floreana was the next of the four islands Darwin visited. The first settlement in the Galápagos had been established there just three years before, populated by convicts from Ecuador; it collapsed a few years later, after some malcontented prisoners took up arms against the local governor. On Floreana, Darwin remarked in his private diary, “I industriously collected all the animals, plants, insects, & reptiles from this Island”—adding, “It will be very interesting to find from future comparison to what district or ‘centre of creation’ the organized beings of this archipelago must be attached.” Still thinking like a creationist, Darwin was seeking to understand the islands’ strange inhabitants within the ruling biological paradigm.

After a brief stop at Tagus Cove, on Isabela, the Beagle headed for Santiago. Darwin, three crew members and his servant, Syms Covington, were left for nine days to collect specimens while the Beagle returned to San Cristóbal to obtain fresh water. Guided by a settler from Floreana who had been sent to hunt tortoises, Darwin ascended to the highlands twice to collect specimens in the humid zone. There he was able to study, in considerable detail, the habits of the tortoise. These lumbering behemoths, he found, came from all over the island to drink water at several small springs near the summit. Hordes of the giants could be seen coming and going, with necks outstretched, burying their heads in the water, “quite regardless of any spectator,” to relieve their thirst. Darwin counted the number of times that the tortoises swallowed in a minute (about ten), determined their average speed (six yards a minute), and studied their diet and mating habits. While in the highlands Darwin and his companions dined exclusively on tortoise meat. He commented that it was very tasty when roasted in the shell or made into soup.

When he was not collecting specimens, Darwin devoted time to trying to understand the islands’ geological features, especially the prominent tuff cones near his campsite at Buccaneer Cove. He was the first geologist to appreciate that such sandstone-like structures, which rise to a height of more than 1,000 feet, owe their peculiar features to submarine eruptions of lava and mud; they mix at high temperatures with seawater, producing tiny particles that shoot into the air and rain down on the land to form huge cinder cones.

On October 17, Darwin and his four Santiago companions reboarded the Beagle with their week’s haul of specimens. The ship spent the next two days completing a survey of the two northernmost islands and then, 36 days after arriving in the archipelago (during which he spent 19 days on land), the Beagle sailed for Tahiti. Although Darwin did not yet fully appreciate it, a revolution in science had begun.

Following in Darwin’s path, one understands hardships that he overcame that are not readily apparent to readers of his publications. Trekking in the Galápagos, everything is dictated by how much water one can carry, which limits each excursion to about three days—or, for longer excursions, requires stashing food and water along a route.

To Darwin, such logistics would have been even more problematic, as he did not have the lightweight equipment, such as aluminum-frame backpacks and plastic water containers, that we have today. Assisted by his servant, Darwin would have brought his geological hammer, a clinometer for measuring inclines, a shotgun for collecting birds, a compass, plant presses, rodent traps, specimen bottles, spirits of wine for preserving invertebrates, a notebook, a sleeping bag, food and, of course, water. With a characteristic understatement (reflecting perhaps his excellent physical conditioning after extensive fieldwork in South America during the previous four years), Darwin wrote of the 3,000-foot climb to the summit of Santiago merely that the walk was “a long one.” During our own climb along this route in 2004, when we were all packing about 70 pounds, one of my expedition companions was so overcome with heat exhaustion that he had to return to our base camp in Buccaneer Cove; another sprained his ankle on the treacherous footing but managed to keep going.

During a previous expedition, I and five companions came to appreciate, much more vividly than we would have liked, Darwin’s comparison of Galápagos lava flows to an imagined scene from the “Infernal regions.” We were on Santiago, where Darwin had camped for nine days, on our way to a region where tortoises could sometimes be found. Our two guides had suggested a shortcut across a coastal lava flow. What none of us could see from the vantage point of our boat’s landing site was that our route involved more than eight miles of almost continuous lava rock—not just the mile or two that our guides had led us to expect. As we began our trek across this perilous field of jagged lava, we had no idea how close to death we would all come. What was supposed to be a 6-hour excursion became a 51-hour nightmare as we climbed over jumbled piles of blocks with razor-sharp edges, and in and out of steep ravines formed by meandering lavas and collapsed lava domes. Such flows, commented Darwin, who ventured onto several smaller ones, were like “a sea petrified in its most boisterous moments.” He added, “Nothing can be imagined more rough or horrid.”

During our second day on that Santiago lava flow, our water ran out. To make matters worse, our two guides had failed to bring any water of their own and were drinking ours. By the afternoon of the third day we were all severely dehydrated and were forced to abandon most of our equipment. In desperation, our guides hacked off a candelabra cactus branch, and we resorted to drinking the juice, which was so bitter that I retched. Before we finally made it to the coast, where a support vessel was frantically looking for us, one member of the expedition was delirious and close to death. He was subsequently hospitalized for five days, back in the United States, and it took him more than a month to recover.

On another occasion I accompanied Charles Darwin Research Station botanist Alan Tye on a search for the rare Lecocarpus shrub, which Darwin had collected in 1835. A member of the daisy family, the plant had not been seen by anyone in a century, causing some botanists to question Darwin’s reported locality. The day was unusually hot, and Tye, after a few hours of hiking, felt the onset of heat exhaustion and asked me to take over the lead. Using a machete to help clear our way through the brush, I too became heat exhausted, and began to vomit. Heat exhaustion turned out to be the least of my problems. I had inadvertently cut the branch of an overhanging manzanillo tree, whose apples are poison to humans but beloved by tortoises. Some of the tree’s sap had gotten onto a wristband I was wearing and then into both of my eyes. The sting from the sap was almost unbearable, and dousing my eyes with water did nothing to help. For the next seven hours I was nearly blinded and could open my eyes for only a few seconds at a time. As I walked back to our campsite, five hours away, I often had to balance, with my eyes shut, on huge boulders in a dry riverbed, and on the edge of lava ravines. Those were the most painful seven hours I have ever spent. Fortunately, Tye and I did find the rare plant we had been seeking, resolving a century-old mystery and establishing that San Cristóbal has two different members of the same Lecocarpus genus.

Darwin personally reported no untoward physical difficulties during his own Galápagos visit, although he and four companions on Santiago did complain about a shortage of fresh water and the oppressive heat, which reached 137 degrees Fahrenheit (the maximum on their thermometer), as measured in the sandy soil outside their tent. Darwin was twice reminded of the potentially lethal outcome of any excursion into the Galápagos wilds. The Beagle’s crew encountered one lost soul, from the American whaler Hydaspy, who had become stranded on Española, and this stroke of good fortune saved his life. Also, Captain FitzRoy recorded that another sailor from an American whaler had gone missing and that the whaler’s crew was out looking for him. One should not be surprised, then, that, while he was engaged in fieldwork, Darwin would have focused his attention substantially on surviving the many hazards of the Galápagos.

Legend has it that Darwin was converted to the theory of evolution, eureka-like, during his visit to the islands. How could he not have been? In retrospect, the evidence for evolution seems so compelling. Darwin tells us in his Journal of Researches, first published in 1839, that his fascination with the “mystery of mysteries”—the origin of new species—was first aroused by a chance discussion on Floreana with Nicholas Lawson, the vice governor of the islands. Based in part on differences in the shape of a tortoise’s shell, Lawson claimed that “he could at once tell from which island any one was brought.” Darwin also noticed that the mockingbirds seemed to be either separate varieties or species on the four islands he visited. If true, he speculated, “such facts would undermine the stability of Species”—the fundamental tenet of creationism, which held that all species had been created in their present, immutable forms.

Darwin’s first reflections about evolution were an afterthought, written during the last leg of the Beagle voyage, nine months after his Galápagos visit. (I owe this historical insight to a curious fact—Darwin was a lousy speller. In 1982 I was able to date Darwin’s earliest and previously undated writings about possible species transformations by analyzing changes in Darwin’s pattern of misspellings during the voyage.) While in the Galápagos, Darwin was far more interested in the islands’ geology than their zoology. We know, moreover, from the complete record of his unpublished scientific notes that he was personally dubious about evolution. For nearly a year and a half following his Galápagos visit, he believed that the tortoises and mockingbirds were probably “only varieties,” a conclusion that did not threaten creationism, which allowed for animals to differ slightly in response to their environments. According to creationist theory, species were a bit like elastic bands. The environment could induce variation, but the inevitable pull of the immutable “type”—which was thought to be an idea in the mind of God—caused species to revert to their original forms. For the creationist, all variation from the “type” was limited by an impassable barrier between true species.

Darwin’s initial failure to appreciate the case for evolution stems in large part from a widely mistaken assumption about the tortoises. Naturalists thought that giant tortoises had been introduced to the Galápagos by buccaneers who had transported them from the Indian Ocean, where similar tortoises are present on several islands. This confusion explains Darwin’s astonishing failure to collect even a single specimen for scientific purposes. He and his servant did take back to England, as pets, two baby tortoises. Those juvenile tortoises further misled Darwin, because differences among subspecies are evident only in adults. Not realizing the importance of tortoises for the theory he would eventually develop about the origins and diversity of living things, Darwin and his fellow shipmates ate their way through 48 adult tortoise specimens and threw their shells overboard.

Darwin’s famous finches also misled him at first. There are 14 finch species in the Galápagos that have all evolved from a single ancestor over the past few million years. They have become one of the most famous cases of species adapting to different ecological niches. From Darwin’s specimen notebooks, it is clear he was fooled into thinking that some of the unusual finch species belonged to the families they have come to mimic through a process called convergent evolution. For example, Darwin thought the cactus finch, whose long, probing beak is specialized for obtaining nectar from cactus flowers (and dodging cactus spines), might be related to birds with long, pointed bills, such as meadowlarks and orioles. He also mistook the warbler finch for a wren. Not realizing that all of the finches were closely related, Darwin had no reason to suppose that they had evolved from a common ancestor, or that they differed from one island to another.

My own discovery, more than 30 years ago, that Darwin had misidentified some of his famous Galápagos finches led me to the Darwin Archive at Cambridge University Library, in England. There I found a manuscript trail that poked further holes in the legend that these birds precipitated an immediate “aha” moment. It was only after Darwin’s return to England, when experts in herpetology and ornithology began to correct his Galápagos reports, that he realized the extent of his collecting oversights and misidentifications. In particular, Darwin had failed to label most of his Galápagos birds by island, so he lacked the crucial evidence that would allow him to argue that different finch species had evolved separately while isolated on different islands of the Galápagos group.

Five months after his return to England, in March 1837, Darwin met with ornithologist John Gould. Five years older than Darwin, Gould was just beginning to become known for his beautifully illustrated monographs on birds, which today are highly prized collectors’ items. One of my most unexpected discoveries in the Darwin archives was the piece of paper on which Darwin recorded his crucial meeting with Gould. This manuscript clearly shows how Darwin’s thinking began to change as a result of Gould’s astute insights about the Galápagos birds. Unlike Darwin, Gould had instantly recognized the related nature of the Galápagos finches, and he also persuaded Darwin, who questioned him closely on the subject, that three of his four Galápagos mockingbirds were separate species rather than “only varieties.” Gould also informed Darwin that 25 of his 26 land birds from the Galápagos were new to science, as well as unique to those islands.

Gould’s taxonomic judgments finally caused Darwin to embrace the theory of evolution. Stunned by the realization that evolving varieties could break the supposedly fixed barrier that, according to creationism, prevents new species from forming, he quickly sought to rectify his previous collecting oversights by requesting island locality information from the carefully labeled collections of three Beagle shipmates. Two of these collections, by Captain FitzRoy and FitzRoy’s steward, Harry Fuller, contained 50 Galápagos birds, including more than 20 finches. Even Darwin’s servant, Covington, had done what Darwin had not, labeling by island his own personal collection of finches, which were later acquired by a private collector in England. The birth of the Darwinian revolution was a highly collaborative enterprise.

The case for evolution presented by this shared ornithological evidence nevertheless remained debatable for nearly a decade. Darwin was not entirely convinced Gould was right that all the finches were separate species, or even that they were all finches. Darwin also knew that, without specimens in hand, island-to-island differences among the tortoises were contestable, even though a French herpetologist told a delighted Darwin in 1838 that at least two species of tortoise existed in the islands.

In 1845 Darwin’s botanist friend Joseph Hooker gave Darwin the definitive evidence he needed to support his theory. Hooker analyzed the numerous plants that Darwin had brought back from the Galápagos. Unlike the birds, the plants all had accurate localities attached to them—not because Darwin had collected the plants with evolutionary theory in mind, but because plants have to be preserved in plant presses shortly after being collected. Hence the specimens from each island had all been pressed together, rather than being intermixed. Hooker eventually identified more than 200 species, half of which were unique to the Galápagos. Of these, three-quarters were confined to single islands—yet other islands often possessed closely related forms also found nowhere else on earth. At last, Darwin had the kind of compelling evidence that he felt he could really trust. As he wrote to Hooker: “I cannot tell you how delighted & astonished I am at the results of your examination; how wonderfully they support my assertion on the differences in the animals of the different islands, about which I have always been fearful.”

It is certainly testimony to Darwin’s intellectual boldness that he had conceived of the theory of evolution some eight years earlier, when he still harbored doubts about how to classify Galápagos tortoises, mockingbirds and finches. To bolster the unorthodox theory, he engaged in an exhaustive, 20-year program of research that ultimately became so convincing that he did not need the inspirational Galápagos evidence to make his case. As a consequence, Darwin devotes only 1 percent of the Origin of Species to the Galápagos, barely more than he allotted to the Madeiras Islands or New Zealand.

I have often wondered why Darwin, prior to the publication of Origin of Species in 1859, was the only person known to have become an evolutionist based on evidence from the Galápagos —especially after Hooker’s compelling botanical study. After all, Captain FitzRoy, John Gould, Joseph Hooker and numerous scientific specialists who helped Darwin with the analysis and publication of his voyage findings were fully aware of the unusual nature of his Galápagos collections. In the end, it is perhaps a question of courageous willingness to consider new and unconventional ways of thinking. When Darwin’s uncle, Josiah Wedgwood, was trying to convince Darwin’s father that young Charles should be allowed to sail on the Beagle, Josiah noted Charles was “a man of enlarged curiosity.”

One repeatedly sees the truth of Wedgwood’s observation. Charles Darwin’s undeniable knack for asking the right questions, bolstered by his five-week visit to an extraordinary workshop of evolution brimming with unasked and unanswered questions, ultimately precipitated the Darwinian revolution. In posing novel questions, Darwin voyaged back to the Galápagos Islands again and again in his mind, reassessing his imperfect evidence in the light of his maturing theory and benefiting from new and better evidence obtained by other researchers.

Although much of what one sees in the Galápagos today appears to be virtually identical to what Darwin described in 1835, the biology and ecology of the islands have been substantially transformed by the introduction of exotic plants, insects and animals. Completely gone from Santiago, for example, are the golden-colored land iguanas, described as so numerous by Darwin in 1835 that “we could not for some time find a spot free from their burrows, on which to pitch our tent.” The principal culprits in this extinction, besides Beagle crew members and other people who found these iguanas very good eating, were the rats, dogs, cats, goats and pigs introduced by mariners and would-be settlers who left their animals to run wild. Along with visiting whalers, early settlers also hunted the giant land tortoises to extinction on some islands, and they nearly wiped them out on other islands. Recently introduced insects and plants—including fire ants, wasps, parasitic flies and quinine trees—have also become highly invasive and threaten the Galápagos ecosystem.

When I first visited the Galápagos, 37 years ago, quinine was not yet a serious problem, and feral goats, which later invaded Isabela’s Volcán Alcedo (home to about 5,000 giant land tortoises), had yet to reach epidemic numbers. But by the 1990s, more than 100,000 goats were devastating the volcano’s vegetation. Darwin himself would doubtless have applauded the indefatigable efforts of the Charles Darwin Research Station and the National Park Service to stem the tide of destruction to the fragile ecosystem, and he would also have marveled at some of the occasional success stories, such as the recent eradication of feral pigs from Santiago.

From the many times I have followed in Darwin’s footsteps to better understand his voyage of discovery, I have come to believe that the Galápagos continue to epitomize one of the key elements of Darwin’s theories. As he argued, over long periods of time natural selection is ultimately responsible for the “endless forms most beautiful and most wonderful” around us. Empowering this evolutionary process on a day-to-day basis is what Darwin termed “the struggle for existence.” This evolutionary engine works its slow but unrelenting biological effects primarily through accidents, starvation and death. Perhaps nowhere else is this harsh biological principle more evident than in the strange islands that inspired Darwin’s scientific revolution.

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Darwin: From the Origin of Species to the Descent of Man

This entry offers a broad historical review of the origin and development of Darwin’s theory of evolution by natural selection through the initial Darwinian phase of the “Darwinian Revolution” up to the publication of the Descent of Man in 1871. The development of evolutionary ideas before Darwin’s work has been treated in the separate entry evolutionary thought before Darwin . Several additional aspects of Darwin’s theory of evolution and his biographical development are dealt with in other entries in this encyclopedia (see the entries on Darwinism ; species ; natural selection ; creationism ). The remainder of this entry will focus on aspects of Darwin’s theory not developed in the other entries. It will also maintain a historical and textual approach. Other entries in this encyclopedia cited at the end of the article and the bibliography should be consulted for discussions beyond this point. The issues will be examined under the following headings:

1.1 Historiographical Issues

1.2 darwin’s early reflections, 2.1. the concept of natural selection.

• 2.2. The Argument of the Published Origin

3.1 The Popular Reception of Darwin’s Theory

3.2 the professional reception of darwin’s theory, 4.1 the genesis of darwin’s descent, 4.2 darwin on mental powers, 4.3 the ethical theory of the descent of man.

• 4.4 The Reception of the Descent

5. Summary and Conclusion

Other internet resources, related entries, acknowledgments, 1. the origins of darwin’s theory.

Charles Darwin’s version of transformism has been the subject of massive historical and philosophical scholarship almost unparalleled in any other area of the history of science. This includes the continued flow of monographic studies and collections of articles on particular aspects of Darwin’s theory (Prestes 2023; R. J. Richards and Ruse 2016; Ruse 2013a, 2009a,b,c; Ruse and Richards 2009; Hodge and Radick 2009; Hösle and Illies 2005; Gayon 1998; Bowler 1996; Depew and Weber 1995; Kohn 1985a). The continuous production of popular and professional biographical studies on Darwin provides ever new insights (Ruse et al. 2013a; Johnson 2012; Desmond and Moore 1991, 2009; Browne 1995, 2002; Bowlby 1990; Bowler 1990). In addition, major editing projects on Darwin’s manuscripts and the completion of the Correspondence , project through the entirety of Darwin’s life, continue to reveal details and new insights into the issues surrounding Darwin’s own thought (Keynes [ed.] 2000; Burkhardt et al. [eds] 1985–2023; Barrett et al. [eds.] 1987). The Cambridge Darwin Online website (see Other Internet Resources ) serves as an international clearinghouse for this worldwide Darwinian scholarship, functioning as a repository for electronic versions of all the original works of Darwin, including manuscripts and related secondary materials. It also supplies a continuously updated guide to current literature.

A long tradition of scholarship has interpreted Darwin’s theory to have originated from a framework defined by endemic British natural history, a British tradition of natural theology defined particularly by William Paley (1743–1805), the methodological precepts of John Herschel (1792–1871), developed in his A Preliminary Discourse on the Study of Natural Philosophy (1830 [1987]), and the geological theories of Charles Lyell (1797–1875). His conversion to the uniformitarian geology of Charles Lyell and to Lyell’s advocacy of “deep” geological time during the voyage of the HMS Beagle (December 1831–October 1836), has been seen as fundamental in his formation (Norman 2013; Herbert 2005; Hodge 1983). Complementing this predominantly anglophone historiography has been the social-constructivist analyses emphasizing the origins of Darwin’s theories in British Political Economy (Young 1985: chps. 2, 4, 5). It has also been argued that a primary generating source of Darwin’s inquiries was his involvement with the British anti-slavery movement, a concern reaching back to his revulsion against slavery developed during the Beagle years (Desmond and Moore 2009).

A body of recent historiography, on the other hand, drawing on the wealth of manuscripts and correspondence that have become available since the 1960s (online at Darwin online “Papers and Manuscripts” section, see Other Internet Resources ) has de-emphasized some of the novelty of Darwin’s views and questions have been raised regarding the validity of the standard biographical picture of the early Darwin. These materials have drawn attention to previously ignored aspects of Darwin’s biography. In particular, the importance of his Edinburgh period from 1825–27, largely discounted in importance by Darwin himself in his late Autobiography , has been seen as critical for his subsequent development (Desmond and Moore 1991; Hodge 1985). As a young medical student at the University of Edinburgh (1825–27), Darwin developed a close relationship with the comparative anatomist Robert Edmond Grant (1793–1874) through the student Plinian Society, and in many respects Grant served as Darwin’s first mentor in science in the pre- Beagle years (Desmond and Moore 1991, chp. 1). Through Grant he was exposed to the transformist theories of Jean Baptiste Lamarck and the Cuvier-Geoffroy debate centered on the Paris Muséum nationale d’histoire naturelle (see entry on evolutionary thought before Darwin , Section 4).

These differing interpretive frameworks make investigations into the origins of Darwin’s theory an active area of historical research. The following section will explore these origins.

In its historical origins, Darwin’s theory was different in kind from its main predecessors in important ways (Ruse 2013b; Sloan 2009a; see also the entry on evolutionary thought before Darwin ). Viewed against a longer historical scenario, Darwin’s theory does not deal with cosmology or the origins of the world and life through naturalistic means, and therefore was more restricted in its theoretical scope than its main predecessors influenced by the reflections of Georges Louis LeClerc de Buffon (1707–1788), Johann Herder (1744–1803, and German Naturphilosophen inspired by Friederich Schelling (1775–1854) . This restriction also distinguished Darwin’s work from the grand evolutionary cosmology put forth anonymously in 1844 by the Scottish publisher Robert Chambers (1802–1871) in his immensely popular Vestiges of the Natural History of Creation , a work which in many respects prepared Victorian society in England, and pre-Civil War America for the acceptance of a general evolutionary theory in some form (Secord 2000; MacPherson 2015). It also distinguishes Darwin’s formulations from the theories of his contemporary Herbert Spencer (1820–1903).

Darwin’s theory first took written form in reflections in a series of notebooks begun during the latter part of the Beagle voyage and continued after the return of the Beagle to England in October of 1836 (Barrett et al., 1987). His reflections on the possibility of species change are first entered in March of 1837 (“Red Notebook”) and are developed in the other notebooks (B–E) through July of 1839 (Barrett et al. 1987; Hodge 2013a, 2009). Beginning with the reflections of the third or “D” “transmutation” Notebook, composed between July and October of 1838, Darwin first worked out the rudiments of what was to become his theory of natural selection. In the parallel “M” and “N” Notebooks, dating between July of 1838 and July of 1839, and in a loose collection called “Old and Useless Notes”, dating from approximately 1838–40, he also developed many of his main ideas on human evolution that would only be made public in the Descent of Man of 1871 (below, Section 4).

To summarize a complex issue, these Notebook reflections show Darwin proceeding through a series of stages in which he first formulated a general theory of the transformation of species by historical descent from common ancestors. He then attempted to work out a causal theory of life that would explain the tendency of life to complexify and diversify (Hodge 2013a, 2009, 1985; Sloan 1986). This causal inquiry into the underlying nature of life, and with it the search for an explanation of life’s innate tendency to develop and complexify, was then replaced by a dramatic shift in focus away from these inquiries. This concern with a causal theory of life was then replaced by a new emphasis on external forces controlling population, a thesis developed from his reading of Thomas Malthus’s (1766–1834) Essay on the Principle of Population (6th ed. 1826). For Malthus, human populaton was assumed to expand geometrically, while food supply expanded arithmetically, leading to an inevitable struggle of humans for existence. The impact of Darwin’s reading of this edition of the Essay in August of 1838, was dramatic. It enabled him to theorize the existence of a constantly-acting dynamic force behind the transformation of species.

Darwin’s innovation was to universalize the Malthusian “principle of population” to apply to all of nature. In so doing, Darwin effectively introduced what may be termed an “inertial” principle into his theory, although such language is never used in his text. Newton’s first law of motion, set forth in his Mathematical Principles of Natural Philosophy (1st ed. 1687), established his physical system upon the tendency of all material bodies to persist eternally either at rest or in uniform motion in a straight line, requiring a causal force explanation for any deviations from this initial state. But Newton did not seek a deeper metaphysical explanation of this inertial state. Law One is simply an “axiom” in Newton’s Principia. Similarly, the principle of population supplied Darwin with the assumption of an initial dynamic state of affairs that was not itself explained within the theory—there is no attempt to account causally for this tendency of living beings universally to reproduce geometrically. Similarly for Darwin, the principle of population functions axiomatically, defining a set of initial conditions from which any deviance from this ideal state demands explanation.

This theoretical shift enabled Darwin to bracket his earlier efforts to develop a causal theory of life, and focus instead on the means by which the dynamic force of population was controlled. This allowed him to emphasize how controls on population worked in company with the phenomenon of slight individual variation between members of the same species, in company with changing conditions of life, to produce a gradual change of form and function over time, leading to new varieties and eventually to new species. This opened up the framework for Darwin’s most important innovation, the concept of “natural” selection.

2. Darwinian Evolution

The primary distinguishing feature of Darwin’s theory that separates it from previous explanations of species change centers on the causal explanation he offered for how this process occurred. Prior theories, such as the theory of Jean-Baptiste Lamarck (see entry on evolutionary thought before Darwin ), relied on the inherent dynamic properties of matter. The change of species was not, in these pre-Darwinian efforts, explained through an adaptive process. Darwin’s emphasis after the composition of Notebook D on the factors controlling population increase, rather than on a dynamic theory of life grounded in vital forces, accounts for many of the differences between Darwin’s theory and those of his predecessors and contemporaries.

These differences can be summarized in the concept of natural selection as the central theoretical component of Darwinian theory. However, the exact meaning of this concept, and the varying ways he stated the principle in the Origin over its six editions (1859–1872), has given rise to multiple interpretations of the meaning of this principle in the history of Darwinism, and the different understandings of his meaning deeply affected different national and cultural receptions of his theory (see below, Section 3 .1).

One way to see the complexity of Darwin’s own thinking on these issues is to follow the textual development of this concept from the close of the Notebook period (1839) to the publication of the Origin of Species in 1859. This period of approximately twenty years involved Darwin in a series of reflections that form successive strata in the final version of his theory of the evolution of species. Understanding the historical sequence of these developments also has significance for subsequent controversies over this concept and the different readings of the Origin as it went through its successive revisions. This historical development of the concept also has some bearing on assessing Darwin’s relevance for more general philosophical questions, such as those surrounding the relevance of his theory for such issues as the concept of a more general teleology of nature.

The earliest set of themes in the manuscript elaboration of natural selection theory can be characterized as those developed through a particular form of the argument from analogy. This took the form of a strong “proportional” form of the analogical argument that equated the relation of human selection to the development of domestic breeds as an argument of the basic form: human selection is to domestic variety formation as natural selection is to natural species formation (White, Hodge and Radick 2021, chps. 4–5). This makes a direct analogy between the actions of nature with those of humans in the process of selection. The specific expressions, and changes, in this analogy are important to follow closely. As this was expressed in the first coherent draft of the theory, a 39-page pencil manuscript written in 1842, this discussion analogized the concept of selection of forms by human agency in the creation of the varieties of domestic animals and plants, to the active selection in the natural world by an almost conscious agency, a “being infinitely more sagacious than man (not an omniscient creator)” who acts over “thousands and thousands of years” on “all the variations which tended towards certain ends” (Darwin 1842 in Glick and Kohn 1996, 91). This agency selects out those features most beneficial to organisms in relation to conditions of life, analogous in its action to the selection by man on domestic forms in the production of different breeds. Interwoven with these references to an almost Platonic demiurge are appeals to the selecting power of an active “Nature”:

Nature’s variation far less, but such selection far more rigid and scrutinizing […] Nature lets <<an>> animal live, till on actual proof it is found less able to do the required work to serve the desired end, man judges solely by his eye, and knows not whether nerves, muscles, arteries, are developed in proportion to the change of external form. (Ibid., 93)

These themes were continued in the 230 page draft of his theory of 1844. Again he referred to the selective action of a wise “Being with penetration sufficient to perceive differences in the outer and innermost organization quite imperceptible to man, and with forethought extending over future centuries to watch with unerring care and select for any object the offspring of an organism produced” (Darwin 1844 in ibid., 101). This selection was made with greater foresight and wisdom than human selection. As he envisions the working of this causal agency,

In accordance with the plan by which this universe seems governed by the Creator, let us consider whether there exist any secondary means in the economy of nature by which the process of selection could go on adapting, nicely and wonderfully, organisms, if in ever so small a degree plastic, to diverse ends. I believe such secondary means do exist. (Ibid., 103).

Darwin returned to these issues in 1856, following a twelve-year period in which he published his Geological Observations on the Volcanic Islands (1844), the second edition of his Journal of Researches (1845), Geological Observations on South America (1846), the four volumes on fossil and living barnacles ( Cirripedia ) (1851, 54, 55), and Geological Observations on Coral Reefs (1851). In addition, he published several smaller papers on invertebrate zoology and on geology, and reported on his experiments on the resistance of seeds to salt water, a topic that would be of importance in his explanation of the population of remote islands.

These intervening inquiries positioned Darwin to deal with the question of species permanence against an extensive empirical background. The initial major synthesis of these investigations takes place in his long manuscript, or “Big Species Book”, commenced in 1856, known in current scholarship as the “Natural Selection” manuscript. This formed the immediate background text behind the published Origin . Although incomplete, the “Natural Selection” manuscript provides insights into many critical issues in Darwin’s thinking. It was also prepared with an eye to the scholarly community. This distinguishes its content and presentation from that of the subsequent “abstract” which became the published Origin of Species . “Natural Selection” contained tables of data, references to scholarly literature, and other apparatus expected of a non-popular work, none of which appeared in the published Origin .

The “Natural Selection” manuscript also contained some new theoretical developments of relevance to the concept of natural selection that are not found in earlier manuscripts. Scholars have noted the introduction in this manuscript of the “principle of divergence”, the thesis that organisms under the action of natural selection will tend to radiate and diversify within their “conditions of life”—the contemporary name for the complex of environmental and species-interaction relationships (Kohn 1985b, 2009). Although the concept of group divergence under the action of natural selection might be seen as an implication of Darwin’s theory from his earliest formulations of the 1830s, nonetheless Darwin’s explicit definition of this as a “principle”, and its discussion in a long late insertion in the “Natural Selection” manuscript, suggests its importance for Darwin’s mature theory. The principle of divergence was now seen by Darwin to form an important link between natural variation and the conditions of existence under the action of the driving force of population increase.

Still evident in the “Natural Selection” manuscript is Darwin’s implicit appeal to some kind of teleological ordering of the process. The action of the masculine-gendered “wise being” of the earlier manuscripts, however, has now been given over entirely to the action of a selective “Nature”, now referred to in the traditional feminine gender. This Nature,

…cares not for mere external appearance; she may be said to scrutinise with a severe eye, every nerve, vessel & muscle; every habit, instinct, shade of constitution,—the whole machinery of the organisation. There will be here no caprice, no favouring: the good will be preserved & the bad rigidly destroyed.… Can we wonder then, that nature’s productions bear the stamp of a far higher perfection than man’s product by artificial selection. With nature the most gradual, steady, unerring, deep-sighted selection,—perfect adaption [sic] to the conditions of existence.… (Darwin 1856–58 [1974: 224–225])

The language of this passage, directly underlying statements about the action of “natural selection” in the first edition of the published Origin , indicates the complexity in the exegesis of Darwin’s meaning of “natural selection” when viewed in light of its historical genesis (Ospovat 1981). The parallels between art and nature, the intentionality implied in the term “selection”, the notion of “perfect” adaptation, and the substantive conception of “nature” as an agency working toward certain ends, all render Darwin’s views on teleological purpose more complex than they are typically interpreted from the standpoint of contemporary Neo-selectionist theory (Lennox 1993, 2013). As will be discussed below, the changes Darwin subsequently made in his formulations of this concept over the history of the Origin have led to different conceptions of what he meant by this principle.

The hurried preparation and publication of the Origin between the summer of 1858 and November of 1859 was prompted by the receipt on June 18 of 1858 of a letter and manuscript from Alfred Russel Wallace (1823–1913) that outlined his remarkably similar views on the possibility of continuous species change under the action of a selection upon natural variation (Wallace 1858 in Glick and Kohn 1996, 337–45). This event had important implications for the subsequent form of Darwin’s published argument. Rapidly condensing the detailed arguments of the unfinished “Natural Selection” manuscript into shorter chapters, Darwin also universalized several claims that he had only developed with reference to specific groups of organisms, or which he had applied only to more limited situations in the manuscript. This resulted in a presentation of his theory at the level of broad generalization. The absence of tables of data, detailed footnotes, and references to the secondary literature in the published version also resulted in predictable criticisms which will be discussed below in Section 3.2 .

2.2. The Central Argument of the Published Origin

The Origin of Species by Means of Natural Selection, or the Preservaton of Favoured Races in the Struggle for Life was issued in London by the publishing house of John Murray on November 24, 1859 (Darwin 1859 [1964]). The structure of the argument presented in the published Origin has been the topic of considerable literature and can only be summarized here. Although Darwin himself described his book as “one long argument”, the exact nature of this argument is not immediately transparent, and alternative interpretations have been made of his reasoning and rhetorical strategies in formulating his evolutionary theory. (Prestes 2023; White, Hodge and Radick 2021; Hodge 2013b, 1977; Hoquet 2013; Hull 2009; Waters 2009; Depew 2009; Ruse 2009; Lennox 2005; Hodge 1983b).

The scholarly reconstruction of Darwin’s methodology employed in the Origin has taken two primary forms. One approach has been to reconstruct it from the standpoint of currently accepted models of scientific explanation, sometimes presenting it as a formal deductive model (Sober 1984). Another, more historical, approach interprets his methodology in the context of accepted canons of scientific explanation found in Victorian discussions of the period (see the entry on Darwinism ; Prestes 2023; White, Hodge and Radick 2021; Hodge 2013b, 1983b, 1977; Hoquet 2013; Hull 2009; Waters 2009; Depew 2009; Lennox 2005). The degree to which Darwin did in fact draw from the available methodological discussions of his contemporaries—John Herschel, William Whewell, John Stuart Mill—is not fully clear from available documentary sources. The claim most readily documented, and defended particularly by White, Hodge and Radick (2021) and M. J. S. Hodge (1977, 1983a), has emphasized the importance of John Herschel’s A Preliminary Discourse on the Study of Natural Philosophy (1830 [1987]), which Darwin read as a young student at Cambridge prior to his departure on the HMS Beagle in December of 1831.

In Herschel’s text he would have encountered the claim that science seeks to determine “true causes”— vera causae— of phenomena through the satisfaction of explicit criteria of adequacy (Herschel, 1830 [1987], chp. 6). This concept Newton had specified in the Principia as the third of his “Rules of Reasoning in Philosophy” (see the entry on Newton’s philosophy , Section 4). Elucidation of such causes was to be the goal of scientific explanation. Vera causae , in Herschel’s formulation, were those necessary to produce the given effects; they were truly active in producing the effects; and they adequately explained these effects.

The other plausible methodological source for Darwin’s mature reasoning was the work of his older contemporary and former Cambridge mentor, the Rev. William Whewell (1794–1866), whose three-volume History of the Inductive Sciences (Whewell 1837) Darwin read with care after his return from his round-the-world voyage (Ruse 2013c, 1975). On this reading, a plausible argument has been made that the actual structure of Darwin’s text is more closely similar to a “Whewellian” model of argument. In Whewell’s accounts of his philosophy of scientific methodology (Whewell 1840, 1858), the emphasis of scientific inquiry is, as Herschel had also argued, to be placed on the discovery of “true causes”. But evidence for the determination of a vera causa was to be demonstrated by the ability of disparate phenomena to be drawn together under a single unifying “Conception of the Mind”, exemplified for Whewell by Newton’s universal law of gravitation. This “Consilience of Inductions”, as Whewell termed this process of theoretical unification under a few simple concepts, was achieved only by true scientific theories employing true causes (Whewell 1840: xxxix). It has therefore been argued that Darwin’s theory fundamentally produces this kind of consilience argument, and that his methodology is more properly aligned with that of Whewell.

A third account, related to the Whewellian reading, is that of David Depew. Building on Darwin’s claim that he was addressing “the general naturalist public,” Darwin is seen as developing what Depew has designated as “situated argumentation”, similar to the views developed by contemporary Oxford logician and rhetorical theorist Richard Whately (1787–1863) (Depew 2009). This rhetorical strategy proceeds by drawing the reader into Darwin’s world by personal narration as it presents a series of limited issues for acceptance in the first three chapters, none of which required of the reader a considerable leap of theoretical assent, and most of which, such as natural variation and Malthusian population increase, had already been recognized in some form in the literature of the period.

As Darwin presented his arguments to the public, he opens with a pair of chapters that draw upon the strong analogy developed in the manuscripts between the action of human art in the production of domestic forms, and the actions of selection “by nature.” The resultant forms are presumed to have arisen through the action of human selection on the slight variations existing between individuals within the same species. The interpretation of this process as implying directional, and even intentional, selection by a providential “Nature” that we have seen in the manuscripts was, however, downplayed in the published work through the importance given by Darwin to the role of “unconscious” selection, a concept not encountered in the Natural Selection manuscript. Such selection denotes the practice even carried out by aboriginal peoples who simply seek to maintain the integrity and survival of a breed or species by preserving the “best” forms.

The domestic breeding analogy is, however, more than a decorative rhetorical strategy. It repeatedly functions for Darwin as the principal empirical example to which he could appeal at several places in the text as a means of visualizing the working of natural selection in nature, and this appeal remains intact through the six editions of the Origin.

From this model of human selection working on small individual natural variations to produce the domestic forms, Darwin then developed in the second chapter the implications of “natural” variation, delaying discussion of the concept of natural selection until Chapter IV. The focus of the second chapter introduces another important issue. Here he extends the discussion of variation developed in Chapter I into a critical analysis of the common understanding of classification as grounded on the definition of species and higher groups based on the possession of essential defining properties. It is in this chapter that Darwin most explicitly develops his own position on the nature of organic species in relation to his theory of descent. It is also in this chapter that he sets forth the ingredients for his attack on one meaning of species “essentialism”.

Darwin’s analysis of the “species question” involves a complex argument that has many implications for how his work was read by his contemporaries and successors, and its interpretation has generated a considerable literature (see the entries on species and Darwinism ; Mallet 2013; R. A. Richards 2010; Wilkins 2009; Stamos 2007; Sloan 2009b, 2013; Beatty 1985).

Prior tradition had been heavily affected by eighteenth-century French naturalist Buffon’s novel conception of organic species in which he made a sharp distinction between “natural” species, defined primarily by fertile interbreeding, and “artificial” species and varieties defined by morphological traits and measurements upon these (see the entry on evolutionary thought before Darwin , Section 3.3). This distinction was utilized selectively by Darwin in an unusual blending of two traditions of discussion that are conflated in creative ways in Darwin’s analysis.

Particularly as the conception of species had been discussed by German natural historians of the early nineteenth-century affected by distinctions introduced by philosopher Immanuel Kant (1724–1804), “Buffonian” species were defined by the material unity of common descent and reproductive continuity. This distinguished them by their historical and material character from the taxonomic species of the “Linnean” tradition of natural history. This distinction between “natural” and “logical” species had maintained a distinction between problems presented in the practical classification of preserved specimens, distinguished by external characters, and those relating to the unity of natural species, which was grounded upon reproductive unity and the sterility criterion (Sloan 2009b).

Remarkable in Darwin’s argument is the way in which he draws selectively in his readings from these two preexistent traditions to undermine the different grounds of species “realism” assumed within both of these traditions of discourse. One framework—what can be considered in his immediate context the “Linnean” tradition—regarded species in the sense of universals of logic or class concepts, whose “reality” was often grounded on the concept of divine creation. The alternative “Buffonian” tradition viewed species more naturalistically as material lineages of descent whose continuity was determined by some kind of immanent principle, such as the possession of a conserving “internal mold” or specifying vital force (see evolutionary thought before Darwin 3.3). The result in Darwin’s hands is a complex terminological interweaving of concepts of Variety, Race, Sub-species, Tribe, and Family that can be shown to be a fusion of different traditions of discussion in the literature of the period. This creative conflation also led to many confusions among his contemporaries about how Darwin actually did conceive of species and species change in time.

Darwin addresses the species question by raising the problems caused by natural variation in the practical discrimination of taxa at the species and varietal levels, an issue with which he had become closely familiar in his taxonomic revision of the Sub-class Cirripedia (barnacles) in his eight-year study on this group. Although the difficulty of taxonomic distinctions at this level was a well-recognized problem in the literature of the time, Darwin subtly transforms this practical problem into a metaphysical ambiguity—the fuzziness of formal taxonomic distinctions created by variation in preserved specimens is seen to imply a similar ambiguity of “natural” species boundaries.

We follow this in reading how natural variation is employed by Darwin in Chapter Two of the Origin to break down the distinction between species and varieties as these concepts were commonly employed in the practical taxonomic literature. The arbitrariness apparent in making distinctions, particularly in plants and invertebrates, meant that such species were only what “naturalists having sound judgment and wide experience” defined them to be ( Origin 1859 [1964], 47). These arguments form the basis for claims by his contemporaries that Darwin was a species “nominalist”, who defined species only as conventional and convenient divisions of a continuum of individuals.

But this feature of Darwin’s discussion of species captures only in part the complexity of his argument. Drawing also on the tradition of species realism developed within the “Buffonian” tradition, Darwin also affirmed that species and varieties are defined by common descent and material relations of interbreeding. Darwin then employed the ambiguity of the distinction between species and varieties created by individual variation in practical taxonomy to undermine the ontological fixity of “natural” species. Varieties are not simply the formal taxonomic subdivisions of a natural species as conceived in the Linnaean tradition. They are, as he terms them, “incipient” species (ibid., 52). This subtly transformed the issue of local variation and adaptation to circumstances into a primary ingredient for historical evolutionary change. The full implications to be drawn from this argument were, however, only to be revealed in Chapter Four of the text.

Before assembling the ingredients of these first two chapters, Darwin then introduced in Chapter Three the concept of a “struggle for existence”. This concept is introduced in a “large and metaphorical sense” that included different levels of organic interactions, from direct struggle for food and space to the struggle for life of a plant in a desert. Although described as an application of Thomas Malthus’s parameter of geometrical increase of population in relation to the arithmetical increase of food supply, Darwin’s use of this concept in fact reinterprets Malthus’s principle, which was formulated only with reference to human population in relation to food supply. It now becomes a general principle governing all of organic life. Thus all organisms, including those comprising food for others, would be governed by the tendency to geometrical increase.

Through this universalization, the controls on population become only in the extreme case grounded directly on the traditional Malthusian limitations of food and space. Normal controls are instead exerted through a complex network of relationships of species acting one on another in predator-prey, parasite-host, and food-web relations. This profound revision of Malthus’s arguments rendered Darwin’s theory deeply “ecological” as this term would later be employed. We can cite two thought experiments employed by Darwin himself as illustrations (ibid., 72–74). The first concerns the explanation of the abundance of red clover in England. This Darwin sees as dependent on the numbers of pollinating humble bees, which are controlled in turn by the number of mice, and these are controlled by the number of cats, making cats the remote determinants of clover abundance. The second instance concerns the explanation of the abundance of Scotch Fir. In this example, the number of fir trees is limited indirectly by the number of cattle.

With the ingredients of the first three chapters in place, Darwin was positioned to assemble these together in his grand synthesis of Chapter Four on “natural” selection. In this long discussion, Darwin develops the main exposition of his central theoretical concept. For his contemporaries and for the subsequent tradition, however, the meaning of Darwin’s concept of “natural” selection was not unambiguously evident for reasons we have outlined above, and these unclarities were to be the source of several persistent lines of disagreement and controversy.

The complexities in Darwin’s presentation of his central principle over the six editions of the published Origin served historically to generate several different readings of his text. In the initial introduction of the principle of natural selection in the first edition of Darwin’s text, it is characterized as “preservation of favourable variations and the rejection of injurious variations” (ibid., 81). When Darwin elaborated on this concept in Chapter Four of the first edition, he continued to describe natural selection in language suggesting that it involved intentional selection, continuing the strong art-nature analogy found in the manuscripts. For example:

As man can produce and certainly has produced a great result by his methodical and unconscious means of selection, what may not nature effect? Man can act only on external and visible characters: nature cares nothing for appearances, except in so far as they may be useful to any being. She can act on every internal organ, on every shade of constitutional difference, on the whole machinery of life. Man selects only for his own good; Nature only for that of the being which she tends. Every selected character is fully exercised by her; and the being is placed under well-suited conditions of life. (Ibid., 83)

The manuscript history behind such passages prevents the simple discounting of these statements as mere rhetorical imagery. As we have seen, the parallel between intentional human selectivity and that of “nature” formed the proportional analogical model upon which the concept of natural selection was originally constructed.

Criticisms that quickly developed over the overt intentionality embedded in such passages, however, led Darwin to revise the argument in editions beginning with the third edition of 1861. From this point onward he explicitly downplayed the intentional and teleological language of the first two editions, denying that his appeals to the selective role of “nature” were anything more than a literary figure. Darwin then moved decisively in the direction of defining natural selection as the description of the action of natural laws working upon organisms rather than as an efficient or final cause of life. He also regrets in his Correspondence his mistake in not utilizing the designation “natural preservation” rather than “natural selection” to characterize his principle (letter to Lyell 28 September 1860, Burkhardt Correspondence 8, 397; also see Darwin Correspondence Project in Other Internet Resources ). In response to criticisms of Alfred Russel Wallace, Darwin then adopted in the fifth edition of 1869 his contemporary (1820–1903) Herbert Spencer’s designator, “survival of the fittest”, as a synonym for “natural selection” (Spencer 1864, 444–45; Darwin 1869, 72). This redefinition further shifted the meaning of natural selection away from the concept that can be extracted from the early texts and drafts. These final statements of the late 1860s and early 70s underlie the tradition of later “mechanistic” and non-teleological understandings of natural selection, a reading developed by his disciples who, in the words of David Depew, “had little use for either his natural theodicy or his image of a benignly scrutinizing selection” (Depew 2009, 253). The degree to which this change preserved the original strong analogy between art and nature can, however, be questioned. Critics of the use of this analogy had argued since the original formulations that the comparison of the two modes of selection actually worked against Darwin’s theory (Wallace 1858 in Glick and Kohn 1997, 343). This critique would also be leveled against Darwin in the critical review of 1867 by Henry Fleeming Jenkin discussed below.

The conceptual synthesis of Chapter Four also introduced discussions of such matters as the conditions under which natural selection most optimally worked, the role of isolation, the causes of the extinction of species, and the principle of divergence. Many of these points were made through the imaginative use of “thought experiments” in which Darwin constructed possible scenarios through which natural selection could bring about substantial change.

One prominent way Darwin captured for the reader the complexity of this process is reflected in the single diagram to appear in all the editions of the Origin . In this illustration, originally located as an Appendix to the first edition, but thereafter moved into Chapter Four, Darwin summarized his conception of how species were formed and diverged from common ancestral points. This image also served to depict the frequent extinction of most lineages, an issue developed in detail in Chapter Ten. It displayed pictorially the principle of divergence, illustrating the general tendency of populations to diverge and fragment under the pressure of population increase. It supplied a way of envisioning relations of taxonomic affinity to time, and illstrated the persistence of some forms unchanged over long geological periods in which stable conditions prevail.

Figure: Tree of life diagram from Origin of Species ( Origin 1859:“Appendix”.

Remarkable about Darwin’s diagram of the tree of life is the relativity of its coordinates. It is first presented as applying only to the divergences taking place in taxa at the species level, with varieties represented by the small lower-case letters within species A–L of a “wide ranging genus”, with the horizontal lines representing time segments measured in terms of a limited number of generations. However, the attentive reader could quickly see that Darwin’s destructive analysis of the distinction between “natural” and “artificial” species in Chapter Two, implied the relativity of the species-variety distinction, this diagram could represent eventually all organic relationships, from those at the non-controversial level of diverging varieties within fixed species, to those of the relations of Species within different genera. Letters A–L could also represent taxa at the level of genera, families or orders. The diagram can thus be applied to relationships between all levels of the Linnaean hierarchy with the time segments representing potentially vast expanses of time, and the horizontal spread of branches the degree of taxonomic divergence over time. In a very few pages of argument, the diagram was generalized to represent the most extensive group relations, encompassing the whole of geological time. Extension of the dotted lines at the bottom could even suggest, as Darwin argues in the last paragraph of the Origin , that all life was a result of “several powers, having been originally breathed into a few forms or into one” (Darwin 1859 [1964], 490). This could suggest a single naturalistic origin of all original forms either by material emergence, or through the action of a vitalistic power of life. Darwin’s use of Biblical language could also be read as allowing for the action of a supernatural cause.

In response to criticisms concerning this latter point, Darwin quickly added to the final paragraph in the second edition of 1860 the phrase “by the Creator” (1860: 484), which remained in all subsequent editions. as did the quotations on the frontispiece from familiar discussions in British natural theology concerning creation by secondary causation. Conceptual space was thereby created for the reading of the Origin by some contemporaries, notably by the Harvard botanist Asa Gray (1810–88), as compatible with traditional natural theology (Gray 1860).

The sweep of the theoretical generalization that closed the natural selection chapter, one restated even more generally in the final paragraph of the book, required Darwin to deal with several obvious objections to the theory that constitute the main “defensive” chapters of the Origin (Five–Nine), and occupy him through the numerous revisions of the text between 1859 and 1872. As suggested by David Depew, the rhetorical structure of the original text developed in an almost “objections and response” structure that resulted in a constant stream of revisions to various editions of the original text as Darwin engaged his opponents (Depew 2009; Peckham 2006). Anticipating at first publication several obvious lines of objection, Darwin devoted much of the text of the original Origin to offering a solution in advance to predictable difficulties. As Darwin outlined these main lines of objection, he discussed, first, the apparent absence of numerous slight gradations between species, both in the present and in the fossil record, of the kind that would seem to be predictable from the gradualist workings of the theory (Chps. Six, Nine). Second, the gradual development of organs and structures of extreme complexity, such as the vertebrate eye, an organ which had since Antiquity served as a mainstay of the argument for external teleological design (Chp. Six). Third, the evolution of the elaborate instincts of animals and the puzzling problem of the evolution of social insects that developed sterile neuter castes, proved to be a particularly difficult issue for Darwin in the manuscript phase of his work and needed some account (Chp. Seven). As a fourth major issue needing attention, the traditional distinction between natural species defined by interfertility, and artificial species defined by morphological differences, required an additional chapter of analysis in which he sought to undermine the absolute character of the interbreeding criterion as a sign of fixed natural species (Chp. Eight).

In Chapter Ten, Darwin developed his interpretation of the fossil record. At issue was the claim by Lamarckian and other transformists, as well as Cuvierian catastrophists such as William Buckland (1784–1856) (see the entry on evolutionary thought before Darwin , Section 4.1), that the fossil record displayed a historical sequence beginning with simpler plants and animals, arriving either by transformism or replacement, at the appearance of more complex forms in geological history. Opposition to this thesis of “geological progressionism” had been made by none other than Darwin’s great mentor in geology, Charles Lyell in his Principles of Geology (Lyell 1832 [1990], vol. 2, chp. xi; Desmond 1984; Bowler 1976). Darwin defended the progressionist view against Lyell’s arguments in this chapter.

To each of the lines of objection to his theory, Darwin offered his contemporaries plausible replies. Additional arguments were worked out through the insertion of numerous textual insertions over the five revisions of the Origin between 1860 and 1872, including the addition of a new chapter to the sixth edition dealing with “miscellaneous” objections, responding primarily to the criticisms of St. George Jackson Mivart (1827–1900) developed in his Genesis of Species (Mivart 1871).

For reasons related both to the condensed and summary form of public presentation, and also as a reflection of the bold conceptual sweep of the theory, the primary argument of the Origin could not gain its force from the data presented by the book itself. Instead, it presented an argument from unifying simplicity, gaining its force and achieving assent from the ability of Darwin’s theory to draw together in its final synthesizing chapters (Ten–Thirteen) a wide variety of issues in taxonomy, comparative anatomy, paleontology, biogeography, and embryology under the simple principles worked out in the first four chapters. This “consilience” argument might be seen as the best reflection of the impact of William Whewell’s methodology (see above).

As Darwin envisioned the issue, with the acceptance of his theory, “a grand untrodden field of inquiry will be opened” in natural history. The long-standing issues of species origins, if not the the explanation of the ultimate origins of life, as well as the causes of their extinction, had been brought within the domain of naturalistic explanation. It is in this context that he makes the sole reference in the text to the claim that “light will be thrown on the origin of man and his history”. And in a statement that will foreshadow the important issues of the Descent of Man of 1871, he speaks of how “Psychology will be based on a new foundation, that of the necessary acquirement of each mental power and capacity by gradation” (ibid., 488)

3. The Reception of the Origin

The broad sweep of Darwin’s claims, the brevity of the empirical evidence actually supplied in the Origin , and the implications of his theory for several more general philosophical and theological issues, opened up a controversy over Darwinian evolution that has waxed and waned over more than 160 years. The theory was inserted into a complex set of different national and cultural receptions the study of which currently forms a scholarly industry in its own right. European, Latin American and Anglophone receptions have been most deeply studied (Bowler 2013a; Gayon 2013; Largent 2013; Glick 1988, 2013; Glick and Shaffer 2014; Engels and Glick 2008; Gliboff 2008; Numbers 1998; Pancaldi, 1991; Todes 1989; Kelly 1981; Hull 1973; Mullen 1964). To these have been added analyses of non-Western recptions (Jin 2020, 2019 a,b; Yang 2013; Shen 2016; Elshakry 2013; Pusey 1983). These analyses display common patterns in both Western and non-Western readings of Darwin’s theory, in which these receptions were conditioned, if not determined, by the pre-existing intellectual, scientific, religious, social, and political contexts into which his works were inserted.

In the anglophone world, Darwin’s theory fell into a complex social environment that in the United States meant into the pre-Civil War slavery debates (Largent 2013; Numbers 1998). In the United Kingdom it was issued against the massive industrial expansion of mid-Victorian society, and the development of professionalized science. To restrict focus to aspects of the British reading public context, the pre-existing popularity of the anonymous Vestiges of the Natural History of Creation of 1844, which had reached 11 editions and sold 23,350 copies by December of 1860 (Secord “Introduction” to Chambers 1844 [1994], xxvii]), with more editions to appear by the end of the century, certainly prepared the groundwork for the general notion of the evolutionary origins of species by the working of secondary natural laws. The Vestiges ’s grand schema of a teleological development of life, from the earliest beginnings of the solar system in a gaseous nebula to the emergence of humanity under the action of a great “law of development”, had also been popularized for Victorian readers by Alfred Lord Tennyson’s epic poem In Memoriam (1850). This Vestiges backdrop provided a context in which some could read Darwin as supplying additional support for the belief in an optimistic historical development of life under teleological guidance of secondary laws with the promise of ultimate historical redemption. Such readings also rendered the Origin seemingly compatible with the progressive evolutionism of Darwin’s contemporary Herbert Spencer (see the entry on Herbert Spencer ). Because of these similarities, Spencer’s writings served as an important vehicle by which Darwin’s views, modified to fit the progressivist views expounded by Spencer, were first introduced in non-Western contexts (Jin 2020, 2019 a,b; Lightman [ed.] 2015; Pusey 1983). Such popular receptions ignored or revised Darwin’s concept of evolution by natural selection to fit these progressivist alternatives.

Outside the United Kingdom, the receptions of Darwin’s work display the importance of local context and pre-existent intellectual and social conditions. Three examples—France, Germany, and China—can be elaborated upon. In France, Darwin’s theory was received against the background of the prior debates over transformism of the 1830s that pitted the theories of Lamarck and Etienne Geoffroy St. Hilaire against Cuvier (Gayon 2013; entry on evolutionary thought before Darwin , 4.1). At least within official French Academic science, these debates had been resolved generally in favor of Cuvier’s anti-transformism. The intellectual framework provided by the “positive philosophy” of Auguste Comte (1798–1857) also worked both for and against Darwin. On one hand, Comte’s emphasis on the historical progress of science over superstition and metaphysics allowed Darwin to be summoned in support of a theory of the progress of science. The Origin was so interpreted in the preface to the first French translation of the Origin made by Clémence Royer (Harvey 2008). On the other hand, the Comtean three stages view of history, with its claim of the historical transcendence of speculative and metaphysical periods of science by a final period of experimental science governed by determinate laws, placed Darwinism in a metaphysical phase of speculative nature philosophy. This view is captured by the assessment of the leading physiologist and methodologist of French Science, Claude Bernard (1813–78). As he stated this in his 1865 treatise on scientific methodology, Darwin’s theory was to be regarded with those of “a Goethe, an Oken, a Carus, a Geoffroy Saint Hilaire”, locating it within speculative philosophy of nature rather than granting it the status of “positive” science (Bernard 1865 [1957], 91–92]).

In the Germanies, Darwin’s work entered a complex social, intellectual and political situation in the wake of the failed efforts to establish a liberal democracy in 1848. It also entered an intellectual culture strongly influenced by the pre-existent philosophical traditions of Kant, Schelling’s Naturphilosophie , German Romanticism, and the Idealism of Fichte and Hegel (R. J. Richards 2002, 2008, 2013; Gliboff 2007, 2008; Mullen 1964). These factors formed a complex political and philosophical environment into which Darwin’s developmental view of nature and theory of the transformation of species was quickly assimilated, if also altered. Many readings of Darwin consequently interpreted his arguments against the background of Schelling’s philosophy of nature. The marshalling of Darwin’s authority in debates over scientific materialism were also brought to the fore by the enthusiastic advocacy of Darwinism in Germany by University of Jena professor of zoology Ernst Heinrich Haeckel (1834–1919). More than any other individual, Haeckel made Darwinismus a major player in the polarized political and religious disputes of Bismarckian Germany (R. J. Richards 2008). Through his polemical writings, such as the Natural History of Creation (1868), Anthropogeny (1874), and Riddle of the Universe (1895–99), Haeckel advocated a materialist monism in the name of Darwin, and used this as a stick with which to beat traditional religion. Much of the historical conflict between religious communities and evolutionary biology can be traced back to Haeckel’s polemical writings, which went through numerous editions and translations, including several English and American editions that appeared into the early decades of the twentieth century.

To turn to a very different context, that of China, Darwin’s works entered Chinese discussions by a curious route. The initial discussions of Darwinian theory were generated by the translation of Thomas Henry Huxley’s 1893 Romanes Lecture “Evolution and Ethics” by the naval science scholar Yan Fu (1854–1921), who had encountered Darwinism while being educated at the Royal Naval College in Greenwich from 1877 to 1879. This translation of Huxley’s lecture, published in 1898 under the name of Tianyan Lun , was accompanied with an extensive commentary by Yan Fu that drew heavily upon the writings of Herbert Spencer which Yan Fu placed in opposition to the arguments of Huxley. This work has been shown to have been the main vehicle by which the Chinese learned indirectly of Darwin’s theory (Jin 2020, 2019 a, b; Yang 2013; Pusey 1983). In the interpretation of Yan Fu and his allies, such as Kan Yuwei (1858–1927), Darwinism was given a progressivist interpretation in line with aspects of Confucianism.

Beginning in 1902, a second phase of Darwinian reception began with a partial translation of the first five chapters of the sixth edition of the Origin by the Chinese scientist, trained in chemistry and metallurgy in Japan and Germany, Ma Junwu (1881–1940). This partial translation, published between 1902 and 1906, again modified the text itself to agree with the progressive evolutionism of Spencer and with the progressivism already encountered in Yan Fu’s popular Tianyan Lun. Only in September of 1920 did the Chinese have Ma Junwu’s full translation of Darwin’s sixth edition. This late translation presented a more faithful rendering of Darwin’s text, including an accurate translation of Darwin’s final views on natural selection (Jin 2019 a, b). As a political reformer and close associate of democratic reformer Sun Yat-Sen (1866–1925), Ma Junwu’s interest in translating Darwin was also was involved with his interest in revolutionary Chinese politics (Jin 2019a, 2022).

The reception of the Origin by those who held positions of professional research and teaching positions in universities, leadership positions in scientific societies, and employment in museums, was complex. These individuals were typically familiar with the empirical evidence and the technical scientific issues under debate in the 1860s in geology, comparative anatomy, embryology, biogeography, and classification theory. This group can usually be distinguished from lay interpreters who may not have made distinctions between the views of Lamarck, Chambers, Schelling, Spencer, and Darwin on the historical development of life.

If we concentrate attention on the reception by these professionals, Darwin’s work received varied endorsement (Hull 1973). Many prominent members of Darwin’s immediate intellectual circle—Adam Sedgwick, William Whewell, Charles Lyell, Richard Owen, and Thomas Huxley—had previously been highly critical of Chambers’s Vestiges in the 1840s for its speculative character and its scientific incompetence (Secord 2000). Darwin himself feared a similar reception, and he recognized the substantial challenge facing him in convincing this group and the larger community of scientific specialists with which he interacted and corresponded widely. With this group he was only partially successful.

Historical studies have revealed that only rarely did members of the scientific elites accept and develop Darwin’s theories exactly as they were presented in his texts. Statistical studies on the reception by the scientific community in England in the first decade after the publication of the Origin have shown a complicated picture in which there was neither wide-spread conversion of the scientific community to Darwin’s views, nor a clear generational stratification between younger converts and older resisters, counter to Darwin’s own predictions in the final chapter of the Origin (Hull et al. 1978). These studies also reveal a distinct willingness within the scientific community to separate acceptance of Darwin’s more general claim of species descent with modification from common ancestors from the endorsement of his explanation of this descent through the action of natural selection on slight morphological variations.

Of central importance in analyzing this complex professional reception was the role assigned by Darwin to the importance of normal individual variation as the source of evolutionary novelty. As we have seen, Darwin had relied on the novel claim that small individual variations—the kind of differences considered by an earlier tradition as merely “accidental”—formed the raw material upon which, by cumulative directional change under the action of natural selection, major changes could be produced sufficient to explain the origin and subsequent differences in all the various forms of life over time. Darwin, however, left the specific causes of this variation unspecified beyond some effect of the environment on the sexual organs. Variation was presented in the Origin with the statement that “the laws governing inheritance are quite unknown” (Darwin 1859 [1964], 13). In keeping with his commitment to the gradualism of Lyellian geology, Darwin also rejected the role of major “sports” or other sources of discontinuous change in this process.

As critics focused their attacks on the claim that such micro-differences between individuals could be accumulated over time without natural limits, Darwin began a series of modifications and revisions of the theory through a back and forth dialogue with his critics that can be followed in his revisions to the text of the Origin . In the fourth edition of 1866, for example, Darwin inserted the claim that the continuous gradualism depicted by his branching diagram was misleading, and that transformative change does not necessarily go on continuously. “It is far more probable that each form remains for long periods unaltered, and then again undergoes modification” (Darwin 1866, 132; Peckham 2006, 213). This change-stasis-change model allowed variation to stabilize for a period of time around a mean value from which additional change could then resume. Such a model would, however, presumably require even more time for its working than the multi-millions of years assumed in the original presentation of the theory.

The difficulties in Darwin’s arguments that had emerged by 1866 were highlighted in a lengthy and telling critique in 1867 by the Scottish engineer Henry Fleeming Jenkin (1833–1885) (typically Fleeming Jenkin). Using an argument previously raised in the 1830s by Charles Lyell against Lamarck, Fleeming Jenkin cited empirical evidence from domestic breeding that suggested a distinct limitation on the degree to which normal variation could be added upon by selection (Fleeming Jenkin 1867 in Hull 1973). Using a loosely mathematical argument, Fleeming Jenkin argued that the effects of intercrossing would continuously swamp deviations from the mean values of characters and result in a tendency of the variation in a population to return to mean values over time. It is also argued that domestic evidence does not warrant an argument for species change. For Fleeming Jenkin, Darwin’s reliance on continuous additive deviation was presumed to be undermined by these arguments, and only more dramatic and discontinuous change—something Darwin explicitly rejected—could account for the origin of new species.

Fleeming Jenkin also argued that the time needed by Darwin’s theory to account for the history of life under the gradual working of natural selection was simply unavailable from scientific evidence, supporting this claim by an appeal to the physical calculations of the probable age of the solar system presented in publications by his mentor, the Glasgow physicist William Thompson (Lord Kelvin, 1824–1907) (Burchfield 1975). On the basis of Thompson’s quantitative physical arguments concerning the age of the sun and solar system, Fleeming Jenkin judged the time since the presumed first beginnings of life to be insufficient for the Darwinian gradualist theory of species transformation to have taken place.

Jenkin’s multi-pronged argument gave Darwin considerable difficulties and set the stage for more detailed empirical inquiries into variation and its causes by Darwin’s successors. The time difficulties were only resolved in the twentieth-century with the discovery of radioactivity that could explain why the sun did not lose heat in accord with Newtonian principles.

As a solution to the variation question, Darwin developed his “provisional hypothesis” of pangenesis, which he presented the year after the appearance of the Fleeming Jenkin review in his two-volume Variation of Plants and Animals Under Domestication (Darwin 1868; Olby 2013). Although this theory had been formulated independently of the Jenkin review (Olby 1963), in effect it functioned as Darwin’s reply to Jenkin’s critique. The pangenesis theory offered a causal theory of variation and inheritance through a return to a theory resembling Buffon’s theory of the organic molecules proposed in the previous century (see entry on evolutionary thought before Darwin section 3.2). Invisible material “gemmules” were presumed to exist within the cells. According to theory, these were subject to external alteration by the environment and other external causes. The gemmules were then shed continually into the blood stream (the “transport” hypothesis) and assembled by “mutual affinity for each other, leading to their aggregation either into buds or into the sexual elements” (Darwin 1868, vol. 2, 375). In this form they were then transmitted—the details were not explained—by sexual generation to the next generation to form the new organism out of “the modified physiological units of which the organism is built” (ibid., 377). In Darwin’s view, this hypothesis united together numerous issues into a coherent and causal theory of inheritance and explained the basis of variation. It also explained how use-disuse inheritance, a theory which Darwin never abandoned, could work.

The pangenesis theory, although not specifically referred to, seems to be behind an important distinction Darwin inserted into the fifth edition of the Origin of 1869 in his direct reply to the criticisms of Jenkin. In this textual revision, Darwin distinguished “certain variations, which no one would rank as mere individual differences”, from ordinary variations (Darwin1869, 105; Peckham 2006, 178–179). This revision shifted Darwin’s emphasis away from his early reliance on normal slight individual variation, and gave new status to what he now termed “strongly marked” variations. The latter were now the forms of variation to be given primary evolutionary significance. Presumably this strong variation was more likely to be transmitted to the offspring, although details are left unclear, and in this form major variation could presumably be maintained in a population against the tendency to swamping by intercrossing as Fleeming Jenkin had argued.

Darwin’s struggles over this issue defined a set of problems that British life scientists in particular were to deal with into the 1930s. These debates over the role of somatic variation in the evolutionary process placed Darwinism in a defensive posture that forced its supporters into major revisions in the Darwinian research program (Gayon 1998; Vorzimmer 1970). The consequence was a complex period of Darwinian history in which natural selection theory was rejected by many research, or defended in modified form by others (Bowler 1983, 2013a; Largent 2009).

4. Human Evolution and the Descent of Man

Darwin had retained his own conclusions on human evolution quietly in the background through the 1860’s while the defense of his general theory was conducted by advocates as diverse as Thomas Henry Huxley (1825–95) in England, Asa Gray (1810–88) in the United States, and Ernst Haeckel (1834–1919) in the emerging new Germany. Darwin’s own position on the “human question” remained unclear to the reading public, and his rhetorical situating of the Origin within a tradition of divine creation by secondary law, captured in the frontispiece quotations from William Whewell and Francis Bacon, allowed many before 1871 to see Darwin as more open to religious interpretations of human origins than those of some of his popularizers.

Darwin’s interest in developing his insights into the origins of human beings and the explanation of human properties through descent with modification was, however, evident in his correspondence as early as January of 1860 when he began collecting evidence on the expressions of the emotions in human beings (Browne 2002, chp. 9). He then developed a questionnaire specifically intended to gain such information from contacts in Patagonia and Tierra del Fuego (Radick 2018). Further engagement with these issues was then generated by the discussions of Lyell (1863) and A. R. Wallace (1864), both of whom suggested that natural selection could not account for the development of the “higher” rational faculties, language, and ethical motivation (R. J. Richards 1987, chp. 4). It was then in February of 1867 that Darwin decided to remove material from his massive manuscript of the Variation of Plants and Animals Under Domestication to create a “very small volume, ‘an essay on the origin of mankind’” (Darwin to Hooker, 8 February 1867 and CD to Turner, 11 February 1867, Burkhardt, Correspondence 15: 74, 80). At this time he also sent to several international correspondents a more detailed questionnaire asking for information on human emotional expression. Further impetus to develop his views was created by the arguments of William R. Greg (1809–1881) in an essay in Fraser’s Magazine (1868), with further support by arguments of A. R. Wallace in 1869, both of whom drew a sharp distinction between human properties and those of animals (R. J. Richards 1987, 172–184). These arguments denied that natural selection could explain the origins of these “higher powers”.

Darwin’s drafting of his views on human issues, begun in early 1868, expanded into a major enterprise in which he became deeply engaged with the issue of the implications of his theory for ethics. The result of this effort devoted to anthropological topics was two separate works: the Descent of Man and Selection in Relation to Sex , delivered to the publisher in June of 1870 with publication in 1871, and its companion, Expression of the Emotions in Man and Animals , which he commenced in early 1871 with publication in early 1872.

As commentators have noted, these two works differ markedly in their arguments, and reflect different relationships to Darwin’s causal theories of natural and sexual selection, with sexual selection predominting over natural selection for the major portion of the Descent , and both of these causal theories generally missing from the descriptive approach of the Expression (Radick 2018).

Sexual selection—the choosing of females by males or vice versa for breeding purposes—had received a general statement by Darwin in Chapter IV of the Origin , but this played only a minor role in the original argument, and its importance was denied by co-evolutionist A. R. Wallace. In the Descent this was now developed in extensive detail as a major factor in evolution that could even work against ordinary natural selection. Sexual selection could be marshaled to explain sexual dimorphism, and also the presence of unusual characters and properties of organisms—elaborate feeding organs, bright colors, and other seemingly maladaptive structures such as the antlers on the Irish Elk or the great horn on the Rhinoceros beetle—that would appear anomalous outcomes of ordinary natural selection working for the optimal survival of organisms in nature. In a dramatic extension of the principle to human beings, the combination of natural and sexual selection is used to explain the origins of human beings from simian ancestors. It also accounts for the sexual dimorphism in humans, and is a major factor accounting for the origin of human races (E. Richards 2017; R. A. Richards 2013).

Although the secondary causal role of sexual selection in the development of species generally was to be the main topic of the bulk of the Descent , this plays an ambiguous role initially in the “treatise on man” that occupies the initial chapters, and functions differently in his treatment of the origins of mental powers, the moral sense, and the origin of races in this opening discussion.

In constructing this presentation, Darwin reaches back to the early Notebooks that he had separated out from the “transformist” discussions to deal with his inquiries into ethics, psychology, and emotions (see Section 1.2 above). Of particular importance for the opening discussions of the Descent was the “M” notebook, commenced in July of 1838, and “N”, begun in October of that year. On occasion he also samples the collection of entries now entitled “Old and Useless Notes”, generally written between 1838 and 1840.

The initial topic of focus in the Descent deals with the far-reaching issues concerning the status and origin of human mental properties, faculties presumed traditionally to be possessed uniquely by human beings. These properties Darwin now places on an evolutionary continuum with those features of animal behavior long regarded as instinctual. In this he placed himself in opposition to the long tradition of discourse that had distinguished humans from animals due to the possession of a “rational principle” related to their possession of a rational soul. This tradition had been given a more radical foundation in the revolutionary reflections on the relation of mind and body initiated by René Descartes (1596–1650) in the middle of the seventeenth century. Descartes deepened this distinction with the separation of the two substances—thinking substance, or res cogitans , possessed only by humans, and extended material substance, res extensa that constituted the rest of the natural world, including animals and plants, rendering animals only lifeless machines without rational faculties.

Darwin’s collapse of this Cartesian barrier with his theory of human origins outlined in the Descent continued a discussion that had been a concern of his transformist predecessors, especially Jean Baptiste Lamarck (Sloan 1999). But Darwin took this issue to a new level as he interpreted the human-animal relationship in the context of his novel theory of divergent evolution from common ancestors. Darwin also broke with the view of humans as the summit of a natural teleological process. Darwin instead denies such teleological ordering, and effectively reduces human properties to those of animals—mental as well as physical—by tracing them to their origin in properties of lower organisms.

The warrant for the identification of human and animal mental properties, however, is not supported by substantial argumentation in the Descent. The opening discussions of the treatise summarize the anatomical evidence for “homologies” —true identities—between humans and animals due to descent from common ancestors, claims already set out in Chapter Thirteen of the Origin. But the transferal of this identity of structure to inner non-anatomical “mental” properties rested on premises that are not made explicit in this text, and were not identities drawn by Huxley, Wallace and Lyell, for example, in their treatments of humans in relation to evolutionary theory, although they acknowledged the anatomical continuities.

To understand Darwin’s arguments, it is useful to return to his Notebook discussions on which he was drawing for his reasoning (see above, Section 1.2). In his “C” Notebook, opened in February of 1838, Darwin has a remarkable entry that displays very early on his commitment to a metaphysical “monism”—the thesis that there is only one substance underlying both mind and body. With this goes the thesis of a parallelism of the complexity of mental properties with those of material structure. In this entry in “C” following on Darwin’s reflections on the issue of instinct, and also recording some of his observations on animals at the Regents Park zoological gardens, Darwin comments:

There is one living spirit, prevalent over this wor[l]d, (subject to certain contingencies of organic matter & chiefly heat), which assumes a multitude of forms <<each having acting principle>> according to subordinate laws.—There is one thinking […] principle (intimately allied to one kind of organic matter—brain. & which <prin> thinking principle. seems to be given or assumed according to a more extended relations [ sic ] of the individuals, whereby choice with memory, or reason ? is necessary.—) which is modified into endless forms, bearing a close relation in degree & kind to the endless forms of the living beings.— We see thus Unity in thinking and acting principle in the various shades of <dif> separation between those individuals thus endowed, & the community of mind, even in the tendency to delicate emotions between races, & recurrent habits in animals.— (Barrett 1987, 305)

As we follow these issues into the “M” Notebook, the assumption of a single “thinking principle,” allied to one kind of organic matter, seems then to underlie Darwin’s subsequent reflections on mind and matter. The “M” Notebook cites numerous “mental”properties common to humans and animals that generally parallel levels of material organization, similar to the identities expressed in the later Descent. The range of this universal extension of mental properties is far-reaching in these early discussions: consciousness and “free will” extends to all animals, including invertebrates:

With respect to free will, seeing a puppy playing cannot doubt that they have free will, if so all animals., then an oyster has & a polype (& a plant in some senses […]; now free will of oyster, one can fancy to be direct effect of organization, by the capacities its senses give it of pain or pleasure, if so free will is to mind, what chance is to matter […] (Barrett 1987, 536).

When these themes reappear in Chapter Two of the first edition of the Descent , Darwin seems to draw implicitly upon this matter-mind identity theory as an obvious consequence of his theory of descent from common ancestry. There he enumerates a long list of traditional human mental and emotional properties to claim that each of them are identities with the properties of simpler forms of life. The list is expansive: courage, deceit, play, kindness, maternal affection, self-complacency, pride, shame, sense of honor, wonder, dread, imitation, imagination, and dreaming. All are considered to be represented in a wide range of animals, with “play”and “recognition” found even in the ants.

When he addresses the more complex mental properties that specifically had been considered by a long tradition of discussion to be the distinctive human properties—possession of language, reason, abstract conceptual thinking, self-reflection—these again are treated as having their manifestations in other forms of life, with none of them unique to human beings. Language, the property that Descartes, for example, had considered to be the primary distinguishing character denoting the human possession of mind as distinct from matter, Darwin treats a developing in a gradual process from animal sounds that parallel the differentiation of species, illustrated by the fact that languages “like organic beings, can be classed in groups under groups” (Darwin 1871 [1981], 60). He closes his discussion of mental powers with an analysis of religious belief that derives it from imagination and belief in spirits found in aboriginal peoples. It can even be homologized with the “deep love of a dog for his master, associated with complete submissions, some fear, and perhaps other feelings” (ibid., 68). Darwin’s discussions of the relation of human and animal mental and emotional properties would set the agenda for a complex discussion that would carry into contemporary debates over animal cognition and the relations of human and animal properties (see the entries on animal cognition ; methods in comparative cognition ; and animal consciousness ).

The subsequent treatment of ethical issues in the third chapter of the Descent was for Darwin a topic to be approached “exclusively from the side of natural history” (ibid., 71). This issue also presented him with some of his most difficult conceptual problems (CD to Gray, 15 March 1870, Burkhardt, Correspondence 18, 68). In this discussion he also employs natural selection theory as an explanatory cause.

Under the heading of “Moral Sense”, Darwin offered some innovations in ethics that do not easily map on to standard ethical positions classified around the familiar categories of Rule or Act Utilitarianism, Kantian Deontology, Hedonism, and Emotivism. Darwin’s closest historical affinities are with the Scottish “Moral Sense” tradition of Frances Hutcheson (1694–1746), Adam Smith (1723?–1790), and David Hume (1711–1776). More immediately Darwin drew from the expositions of the moral sense theory by his distant relative, Sir James Macintosh (1765–1832) (R. J. Richards 1987, 114–122, 206–219).

Traditional moral sense theory linked ethical behavior to an innate property that was considered to be universal in human beings, although it required education and cultivation to reach its full expression (see the entry on moral sentimentalism ). This inherent property, or “moral” sense, presumably explained such phenomena as ethical conscience, the sense of moral duty, and it accounted for altruistic actions that could not be reduced to hedonic seeking of pleasure and avoiding pain. It also did not involve the rational calculation of advantage, or the maximization of greatest happiness by an individual prior to action, as implied by Utilitarianism. For this reason Darwin criticized John Stuart Mill’s version of Utilitarian theory because it relied on acquired habits and the calculation of advantage (Darwin 1871 [1981], 71n5).

Darwin’s reinterpretation of the moral sense tradition within his evolutionary framework also implied important transfomations of this theory of ethics. The moral sense was not to be distinguished from animal instinct but was instead derived historically from the social instincts and developed by natural selection. From this perspective, Darwin could claim a genuine identity of ethical foundations holding between humans and animals, with the precursors of human ethical behavior found in the behavior of other animals, particularly those with social organization. Natural selection then shaped these ethical instincts in ways that favored group survival over immediate individual benefit (ibid., 98). Human ethical behavior is therefore grounded in a natural property developed by natural selection, with the consequence that ethical actions can occur without moral calculus or rational deliberation.

When moral conflict occurs, this is generally attributed to a conflict of instincts, with the stronger of two conflicting instincts favored by natural selection insofar as it favors group benefit (ibid. 84). In human beings the “more enduring Social Instincts” thus come to override the less persistent “individual” instincts.

The adequacy of evolutionary ethical naturalism as a foundation for ethical realism proved to be a point of contention for Darwin’s contemporaries and successors following the publication of the Descent . For some moral philosophers, Darwin had simply reduced ethics to a property subject to the relativizing tendencies of natural selection (Farber 1994: chp. 5). It was, in the view of Darwin’s philosophical critics, to reduce ethics to biology and in doing so, to offer no way to distinguish ethical goods from survival advantages. Not even for some strong supporters of Darwinism, such as Thomas Huxley and Alfred Russel Wallace, was Darwin’s account adequate (ibid., chp. 4). Much of subsequent development of moral philosophy after Darwin would be grounded upon the canonical acceptance of the “is-ought” distinction, which emerged with new force from the critique of “evolutionary” ethical theory. This critique began with Thomas Huxley’s own break with Darwinian ethical theory in his Romanes Lecture, “Evolution and Ethics”of 1893 (Huxley 1893). This lecture, reflecting Huxley’s views eleven years after Darwin’s death, would play an important role in the Chinese reception of Darwinism (Huxley 1895; see above, section 3.1). This line of critique also received an influential academic expression in G. E. Moore’s (1873–1958) Principia Ethica —itself an attack on Spencer’s version of evolutionary ethics (Moore 1903). Debates over the adequacy of evolutionary ethics continue into the present (see the entries on biological altruism and morality and evolutionary biology ; see also, R. J. Richards 2015, 2009, 1999, 1987, Appendix 2; Charmetant 2013; Boniolo and DeAnna (eds.) 2006; Hauser 2006; Katz (ed.) 2000; Maienschein and Ruse (eds.) 1999).

4.4 Reception of the Descent

The international reception of the Descent of Man and Expression of the Emotions is a topic in need of the kind of detailed studies that surround the historical impact of the Origin. These works presented the reading public after 1871 with a more radical and controversial Darwin than had been associated with the author of the popular Journal of Researches or even the Origin itself, and his anthropological works created a watershed in the public reception of Darwin’s views (Radick 2013). The Descent finally made public Darwin’s more radical conclusions about human origins, and seemed to many of his readers, even those previously sympathetic to the Origin , to throw Darwin’s authority behind materialist and anti-religious forces. Public knowledge of Darwin’s own conclusions on human evolution before 1871 had rested on the one vague sentence on the issue in the Origin itself. The Descent made public his more radical conclusions. Even though the question of human evolution had already been dealt with in part by Thomas Huxley in his Man’s Place in Nature of 1863 (Huxley 1863), and by Charles Lyell in the same year in his Geological Evidences of the Antiquity of Man (Lyell 1863), followed by Alfred Russel Wallace’s articles in 1864 and 1870 (Wallace 1864 and online), these authors had either not dealt with the full range of questions presented by the inclusion of human beings in the evolutionary process, or they had emphasized the moral and mental discontinuity between humans and animals. Only Ernst Heinrich Haeckel had drawn out a more general reductive conception of humanity from evolutionary theory and he had not ventured into the specific issues of ethics, social organization, the origins of human races, and the relation of human mental properties to those of animals, all of which are dealt with in the Descent . Darwin’s treatise presented, as one commentator has put it, “a closer resemblance to Darwin’s early naturalistic vision than anything else he ever published” (Durant 1985, 294).

Darwin’s extension of his theory to a range of questions traditionally discussed within philosophy, theology, and social and political theory, has shaped the more general history of Darwinism since the 1870s. It set the agenda for much of the development of psychology of the late nineteenth century (R. J. Richards 1987). It also hardened the opposition of many religiously-based communities against evolutionary theory, although here again, distinctions must be made between different communities (Ellegård 1990, chp. 14). Such opposition was not simply based upon the denial of the literal scriptural account of the origins of humankind, an issue that played out differently within the main religious denominations (Haught 2013; Finnegan 2013; Swetlitz 2013; Artigas, Glick, & Martinez 2006; Moore 1979). The more fundamental opposition was due to the denial of distinctions, other than those of degree, between fundamental human properties and those of animals.

Furthermore, the apparent denial of some kind of divine guidance in the processes behind human evolution and the non-teleological character of Darwin’s final formulations of the natural selection theory in the fifth and sixth editions of the Origin , hardened this opposition. His adoption from Herbert Spencer of designator “survival of the fittest” as a synonym for “natural selection” in the fifth edition of 1869 added to this growing opposition. As a consequence, the favorable readings that many influential religious thinkers—John Henry Newman (1801–1890) is a good example—had given to the original Origin , disappeared. The rhetoric of the Descent , with its conclusion that “man is descended from a hairy quadruped, furnished with a tail and pointed ears” (Darwin 1871 [1981], 389), presented to the public a different Darwin than many had associated with the popular seagoing naturalist.

The new opposition to Darwin is reflected in the many hostile reviews of the Descent to appear in the periodical press (R. J. Richards 1987, 219–230). Particularly at issue were Darwin’s accounts of the origin of ethical principles and intelletual powers, including language, self-reflection, abstract thinking and religious belief as derivations from animal properties (Anon. 1871)

The profound revolution in thought that Darwin created, however, was eventually recognized even by his one-time harsh critics. The once leading British comparative anatomist Richard Owen (1804–1892), who had long been estranged from Darwin since his harsh review of the Origin in 1860, nonetheless could comment on the occasion of Darwin’s burial in Westminster Abbey in a letter to Horace Walpole:

The great value of Darwin’s series of works, summarizing all the evidence of Embryology, Paleontology, & Physiology experimentally applied in producing Varieties of Species, is exemplified in the general acceptance by Biologists of the Secondary Law, by Evolution, of the ‘Origin of Species’ […] In this respect Charles Darwin stands to Biology in the relation which Copernicus stood to Astronomy. […] [Copernicus] knew not how the planets revolved around the sun. To know that required the successive labours of a Galileo, a Kepler and finally a Newton […] Meanwhile our British Copernicus of Biology merits the honour and the gratitude of the Empire, which is manifest by a Statue in Westminster Abbey. (Richard Owen to Horace Walpole, 5 November, 1882, Royal College of Surgeons of England Archives, MS0025/1/5/4).

The subsequent history of the debates surrounding Darwin’s achievement forms a complex story that involves much of the history of life science, as well as ethical theory, psychology, philosophy, theology and social theory since 1870. For a general summary of recent scholarship see Ruse 2013a and articles from this encyclopedia listed below.

This article has intended to give a historical overview of the specific nature of Darwinian theory, and outline the ways in which it differed from the theories of predecessors in the nineteenth century (see the entry evolution before Darwin ). The eventual general consensus achieved by the middle of the twentieth century around the so-named “Synthetic” theory of evolution that would combine population genetics with a mathematical analysis of evolutionary change, has formed a successful research program for more than half a century (Smocovitis 1996; Mayr and Provine 1980; Provine 1971). This “synthesis” has been challenged in recent decades by the current movement known as evolutionary developmental theory, or “evo-devo”. This development represents in some important respects a return to presumably discarded traditions and lines of exploration of the nineteenth and early twentieth centuries which sought to link evolution with embryological development, and to a complex understanding of genetics, with re-examination of the effects of external conditions on inheritance (Gilbert 2015; Newman 2015; Laubichler and Maienschein 2007; Gissis and Jablonka 2011; Pigliucci and Müller 2010; Amundson 2005; Gilbert, Opitz and Raff 1996). Where these debates and revisions in evolutionary theory may lead in another fifty years is a matter of speculation (Gayon 2015 in Sloan, McKenny and Eggleson 2015).

More general philosophical issues associated with evolutionary theory—those surrounding natural teleology, ethics, the relation of evolutionary naturalism to the claims of religious traditions, the implications for the relation of human beings to the rest of the organic world—continue as issues of scholarly inquiry. The status of Darwin’s accounts of human mental powers and moral properties continue to be issues of philosophical debate. The adequacy of his reliance on sexual selection to explain sex and gender roles in human society form heated topics in some feminist scholarship. Such developments suggest that there are still substantial theoretical issues at stake that may alter the future understanding of evolutionary theory in important ways (Sloan, McKenny, & Eggleson [eds] 2015).

• Amundson, Ron, 2005, The Changing Role of the Embryo in Evolutionary Thought: Roots of Evo-Devo , Cambridge: Cambridge University Press. doi:10.1017/CBO9781139164856
• Anon., “Review of the Descent of Man and Selection in Relation to Sex” , Edinburgh Review 134 (July 1871), 195–235.
• Artigas, Mariano, Thomas F. Glick, and Rafael A. Martínez, 2006, Negotiating Darwin: The Vatican Confronts Evolution, 1877–1902 , Baltimore, MD: Johns Hopkins University Press.
• Barrett, Paul H., Peter J. Gautrey, Sandra Herbert, David Kohn, and Sydney Smith (eds.), 1987, Charles Darwin’s Notebooks: 1836–1844 , Cambridge: Cambridge University Press. [online manuscripts at Darwin’s notebooks and reading lists.]
• Beatty, John 1985, “Speaking of Species: Darwin’s Strategy”, in Kohn 1985a: 265–281. doi:10.1515/9781400854714.265
• Bernard, Claude, 1865 [1957], Introduction to the Study of Experimental Medicine , translated Henry Copley Greene, New York: Dover. Originally published in 1927, New York:Macmillan. [ Bernard 1865 available online ]
• Boniolo, Giovanni and Gabriele De Anna (eds.) 2006, Evolutionary Ethics an Contemporary Biology, Cambridge: Cambridge University Press.
• Bowlby, John, 1990, Charles Darwin: A New Life , New York: Norton.
• Bowler, Peter J., 1976, Fossils and Progress: Paleontology and the Idea of Progressive Evolution in the Nineteenth Century , New York: Science History.
• –––, 1983, The Eclipse of Darwinism: Anti-Darwinian Evolution Theories in the Decades Around 1900 , Baltimore, MD: Johns Hopkins University Press.
• –––, 1990, Charles Darwin: The Man and His Influence , Oxford: Blackwell.
• –––, 1996, Life’s Splendid Drama: Evolutionary Biology and the Reconstruction of Life’s Ancestry, 1860–1940 , Chicago: University of Chicago Press.
• –––, 2013a, “Darwinism in Britain”, in Ruse 2013a: 218–225. doi:10.1017/CBO9781139026895.028
• Browne, Janet, 1995, Charles Darwin: Voyaging , New York: Knopf.
• –––, 2002, Charles Darwin: The Power of Place , Princeton: Princeton University Press.
• Burchfield, Joe D., 1975, Lord Kelvin and the Age of the Earth , Chicago: University of Chicago Press.
• Burkhardt, Frederick et al., (eds.), 1985–2023, The Correspondence of Charles Darwin , 30 volumes. Cambridge: Cambridge University Press.
• Chambers, Robert, 1844 [1994], Vestiges of the Natural History of Creation , facsimile reprint of first edition, J. Secord (ed.), Chicago: University of Chicago Press. [ Chambers 1844 available online ]
• Charmetant, Erin. 2013,“Darwin and Ethics”, in Ruse 2013a, 188–194.
• Darwin, Charles Robert, 1836–1844 [1987], Charles Darwin’s Notebooks: 1836–1844 , Paul H. Barrett, Peter J. Gautrey, Sandra Herbert, David Kohn, and Sydney Smith (eds.), Cambridge: Cambridge University Press. See also the Darwin Online section on Darwin’s notebooks and reading lists .
• –––, 1856–1858 [1974], Charles Darwin’s “Natural Selection”, Being the Second Part of his Big Species Book Written from 1856 to 1858 , R.C. Stauffer (ed.), 1974, Cambridge: Cambridge University Press. [ Natural Selection 1974 available online ]
• –––, 1842 [1996], “1842 Sketch On Selection Under Domestication, Natural Selection, and Organic Beings in the Wild State”, selection in Glick and Kohn 1996, 89–99.
• –––, 1844a [1996], “1844 Essay: Variation of Organic Beings in the Wild State”, in Glick and Kohn 1996, 99–115.
• –––, 1859 [1964], On the Origin of Species By Means of Natural Selection , London: Murray. Facsimile reprint, ed. E. Mayr Cambridge, MA: Harvard University Press [ Origin first edition available online ]
• –––, 1860, second edition [ Origin second edition available online ]
• –––, 1861, third edition, [ Origin third edition available online ]
• –––, 1862, first French edition, De l’origine des espèces , Clémence Royer (trans.), Paris: Guillaumin. [ Origin French first edition available online ]
• –––, 1866, fourth edition, [ Origin fourth edition available online ]
• –––, 1869, fifth edition, [ Origin fifth edition available online ]
• –––, 1872, sixth edition, [ Origin sixth edition available online
• –––, 1868, The Variation of Animals and Plants Under Domestication , two volumes, London: John Murray. First edition available online
• –––, 1871 [1981], The Descent of Man, and Selection in Relation to Sex , two volumes, London: John Murray. Reprinted, ed John T. Bonner and Robert May, Princeton: Princeton University Press [ Descent 1871 available online ]
• –––, 1872, Expression of the Emotions in Man and the Animals , London: John Murray. [ Expression available online ]
• Depew, David J., 2009, “The Rhetoric of the Origin of Species”, in Ruse and Richards 2009: 237–255. doi:10.1017/CCOL9780521870795.015
• Depew, David J. and Bruce H. Weber, 1995, Darwinism Evolving: Systems Dynamics and the Genealogy of Natural Selection , Cambridge, MA: MIT Press.
• Desmond, Adrian J., 1984, Archetypes and Ancestors: Palaeontology in Victorian London, 1850–1875 , Chicago: University of Chicago Press.
• –––, and James R. Moore, 1991, Darwin , London: Michael Joseph.
• –––, and James R. Moore, 2009, Darwin’s Sacred Cause: How a Hatred of Slavery Shaped Darwin’s Views on Human Evolution , Boston: Houghton, Mifflin, Harcourt.
• Durant, John R., 1985, “The Ascent of Nature in Darwin’s Descent of Man ”, in Kohn 1985a: 283–306. doi:10.1515/9781400854714.283
• Ellegård, Alvar, 1990, Darwin and the General Reader; the Reception of Darwin’s Theory of Evolution in the British Periodical Press, 1859–1872 , reprint of 1958 edition, Chicago: University of Chicago Press.
• Elshakry, Marwa, 2013, Reading Darwin in Arabic, 1860–1950. Chicago: University of Chicago Press.
• Engels, Eve-Marie and Thomas F. Glick (eds.), 2008, The Reception of Charles Darwin in Europe , London/New York: Continuum.
• Farber, Paul Lawrence, 1994, The Temptations of Evolutionary Ethics , Berkeley: University of California Press.
• Finnegan, Diarmid A., 2013, “Darwin and Protestantism”, in Ruse 2013a: 468–475. doi:10.1017/CBO9781139026895.060
• Gayon, Jean, 1998, Darwinism’s Struggle for Survival: Heredity and the Hypothesis of Natural Selection , Cambridge: Cambridge University Press.
• –––, 2013, “Darwin and Darwinism in France before 1900”, in Ruse 2013a: 243–249. doi:10.1017/CBO9781139026895.031
• –––, 2015, “What Future for Darwinism?”, in Sloan, McKenny and Eggleson 2015: 404–423.
• Gilbert, Scott F., 2015, “Evolution Through Developmental Change”, in Sloan, McKenny, & Eggleson 2015: 35–60.
• –––, John M. Opitz, and Rudolf A. Raff, 1996, “Resynthesizing Evolutionary and Developmental Biology”, Developmental Biology , 173 (2): 357–372. doi:10.1006/dbio.1996.0032
• Gissis, Snait B. and Eva Jablonka (eds.), 2011, Transformations of Lamarckism: From Subtle Fluids to Molecular Biology , (Vienna Series in Theoretical Biology), Cambridge, MA: MIT Press.
• Gliboff, Sander, 2007, “H. G. Bronn and the History of Nature”, Journal of the History of Biology , 40 (2): 259–294. doi:10.1007/s10739-006-9114-4
• –––, 2008, H. G. Bronn, Ernst Haeckel, and the Origins of German Darwinism: A Study in Translation and Transformation , Cambridge, MA: MIT Press.
• Glick, Thomas F. (ed.), 1988, The Comparative Reception of Darwinism , New edition with new preface, Chicago: University of Chicago Press.
• –––, 2013, “Darwinism in Latin America”, in Ruse 2013a: 258–263. doi:10.1017/CBO9781139026895.033
• –––, and Elinor S. Shaffer (eds.), 2014, The Literary and Cultural Reception of Charles Darwin in Europe , London: Bloomsbury.
• –––, and David Kohn (eds.), 1996, On Evolution: The Development of the Theory of Natural Selection , Indianapolis, IN: Hackett.
• Gray, Asa, 1860, “Review: The Origin of Species by Means of Natural Selection”, American Journal of Science and Arts , series 2, 29: 153–184, written anonymously. doi:10.2475/ajs.s2-29.86.153 [ Gray 1860 available online ]
• Haeckel, Ernst, 1868 [1876], Natürliche Schöpfungsgeschichte , Berlin: G. Reimer. Translated as The History of Creation , two volumes, London: Henry S. King.
• –––, 1874 [1879], Anthropogenie oder Entwickelungsgeschichte des Menschen , translated as The Evolution of Man: A Popular Exposition of the Principal Points of Human Ontogeny and Phylogeny. New York: Appleton.
• –––, 1895–99 [1901], Die Welträthsel ( Riddle of the Universe ). Translated by Joseph McCabe, New York/London: Harper and Brothers.
• Harvey, Joy, 2008, “Darwin in French Dress: Translating, Publishing and Supporting Darwin in Nineteenth-Century France”, in Engels and Glick 2008: 354–374.
• Hauser, Marc D., 2006, Moral Minds: How Nature Designed Our Universal Sense of Right and Wrong , New York: Ecco.
• Haught, John F., 2013, “Darwin and Catholicism”, in Ruse 2013a: 485–492. doi:10.1017/CBO9781139026895.062
• Herbert, Sandra, 2005, Charles Darwin, Geologist , Ithaca, NY: Cornell University Press.
• Herschel, John F. W., 1830 [1987], A Preliminary Discourse on the Study of Natural Philosophy , reprint, Chicago: University of Chicago Press. [ Herschel 1830 available online ]
• Hodge, Jonathan [M.J.S.}, 1977, “The Structure and Strategy of Darwin’s ‘Long Argument’”, British Journal for the History of Science , 10(3): 237. doi:10.1017/S0007087400015685
• –––,1983a, “Darwin and the Laws of the Animate Part of the Terrestrial System (1835–1837): On the Lyellian Origins of His Zoonomical Explanatory Program”, Studies in the History of Biology , 6: 1–106.
• –––, 1983b, “The Development of Darwin’s General Biological Theorizing”, in D. S. Bendall, Evolution From Molecules to Men , Cambridge: Cambridge University Press, 43–62.
• –––, 1985, “Darwin as a Lifelong Generation Theorist”, in Kohn 1985a: 207–243. doi:10.1515/9781400854714.207
• –––, 2009, “The Notebook Programmes and Projects of Darwin’s London Years”, in Hodge and Radick 2009: 44–72, doi:10.1017/CCOL9780521884754.003
• –––, 2013a, “The Origins of the Origin ”, in Ruse 2013a: 64–71. doi:10.1017/CBO9781139026895.007
• –––, 2013b, “Darwin’s Book: On the Origin of Species ”, Science and Education , 22(9): 2267–2294. doi:10.1007/s11191-012-9544-7
• –––, and Gregory Radick (eds.), 2009, The Cambridge Companion to Darwin , Second edition, 2009, doi:10.1017/CCOL9780521884754.
• Hoquet, Thierry, 2013, “The Evolution of the Origin (1859–1872)”, in Ruse 2013a: 158–164. doi:10.1017/CBO9781139026895.020
• Hösle, Vittorio and Christian Illies (eds.), 2005, Darwinism and Philosophy , Notre Dame, IN: University of Notre Dame Press.
• Hull, David L. (ed.), 1973, Darwin and His Critics: The Reception of Darwin’s Theory of Evolution by the Scientific Community , Cambridge, MA: Harvard University Press.
• –––, 2009, “Darwin’s Science and Victorian Philosophy of Science”, in Hodge and Gregory Radick 2009: 173–196, doi:10.1017/CCOL9780521884754.008
• –––, Peter D. Tessner, and Arthur M. Diamond, 1978, “Planck’s Principle”, Science , 202(4369): 717–723. doi:10.1126/science.202.4369.717
• Huxley, Thomas Henry, 1863, Evidence as to Man’s Place in Nature , London: Williams and Norgate. [ Huxley 1863 available online ]
• –––, 1893, “Evolution and Ethics”, London: Macmillan. Romanes lecture.
• –––, 1895, Evolution and Ethics and Other Essays , London: Macmillan. Includes a “Prolegomena”. Parts translated into Chinese by Yan Fu as 天演論 ( Tianyan lun ), 1898. [ Huxley 1895 available online ] [ Yan Fu translation of Huxley 1895 available online ]
• Jenkin, H. Fleeming, 1867 [1973], “[Review] The Origin of Species”, The North British Review , 46 (June): 277–318. Reprinted in Hull 1973: 303–350. [ Jenkin 1867 available online ]
• Jin, Xiaoxing, 2019a, “Darwin in China, 1870–1935”, Unpublished Ph.D. Thesis, University of Notre Dame.
• –––, 2019b, “Translation and Transmutation: The Origin of Species in China”, The British Journal for the History of Science , 52(1): 117–141. doi:10.1017/S0007087418000808.
• –––, 2020, “The Evolution of Evolutionism in China, 1870–1930”, Isis 111(1): 46–66. doi: https://doi.org/10.1086/708367.
• –––, 2022, “The Evolution of Social Darwinism in China, 1895–1930”, Comparative Studies in Society and History 64(3): 690–721. doi: https://doi.org/10.1017/S0010417522000214.
• Johnson, Paul, 2012, Darwin: Portrait of a Genius , New York: Viking.
• Katz, Leonard D. (ed.), 2000, Evolutionary Origins of Morality: Cross-Disciplinary Perspectives , Exeter, UK: Imprint Academic.
• Kelly, Alfred, 1981, The Descent of Darwin: The Popularization of Darwinism in Germany, 1860–1914 , Chapel Hill, NC: University of North Carolina Press.
• Keynes, Richard (ed.), 2000, Charles Darwin’s Zoology Notes & Specimen Lists from H.M.S. Beagle , Cambridge: Cambridge University Press. [ Keynes 2000 available online ]
• Kohn, David (ed.), 1985a, The Darwinian Heritage , Princeton: Princeton University Press. doi:10.1515/9781400854714
• –––, 1985b, “Darwin’s Principle of Divergence as Internal Dialogue”, in Kohn 1985a: 245–257. doi:10.1515/9781400854714.245
• –––, 2009, “Darwin’s Keystone: The Principle of Divergence”, in Ruse and Richards 2009: 87–108, doi:10.1017/CCOL9780521870795.008.
• Laubichler, Manfred Dietrich and Jane Maienschein (eds.), 2007, From Embryology to Evo-Devo: A History of Developmental Evolution , (Dibner Institute Studies in the History of Science and Technology), Cambridge, MA: MIT Press.
• –––, 2013, “Developmental Evolution”, in Ruse 2013a: 375–382. doi:10.1017/CBO9781139026895.048
• Largent, Mark, 2013, “Darwinism in the United States, 1859–1930”, in Ruse 2013a: 226–234.
• –––, 2009. “The So-Called Eclipse of Darwinism”, Transactions of the American Philosophical Society , 99(4): 3–21.
• Lennox, James G., 1993, “Darwin Was a Teleologist”, Biology & Philosophy , 8(4): 409–421. doi:10.1007/BF00857687
• –––, 2005, “Darwin’s Methodological Evolution”, Journal of the History of Biology , 38(1): 85–99. doi:10.1007/s10739-004-6511-4
• –––, 2013, “Darwin and Teleology”, in Ruse 2013a: 152–157. doi:10.1017/CBO9781139026895.019
• Lightman, Bernard (ed.), 2015, Global Spencerism: The Communication and Appropriation of a British Evolutionist , Leiden: Brill. doi:10.1163/9789004264007
• Lyell, Charles, 1830–33 [1990], Principles of Geology , 3 vols. London: Murray, facsimile reprint, ed. Martin J. Rudwick, Chicago: University of Chicago Press.
• –––, 1863, The Geological Evidences of the Antiquity of Man , London: John Murray. [ Lyell 1863 available online ]
• MacPherson, Ryan, 2015, Debating Evolution Before Darwinism: An Exploration of Science and Religion in America, 1844–1859 , Mantako, MN: Into Your Hands Press.
• Maienschein, Jane and Michael Ruse (eds.), 1999, Biology and the Foundation of Ethics , Cambridge: Cambridge University Press. doi:10.1017/CBO9780511609077
• Mallet, James, 2013, “Darwin and Species”, in Ruse 2013a: 109–115. doi:10.1017/CBO9781139026895.013
• Malthus, Thomas, 1826, An Essay on the Principle of Population , 6th edition. London.[available online]
• Mayr, Ernst and William B. Provine (eds.), 1980, The Evolutionary Synthesis: Perspectives on the Unification of Biology , Cambridge, MA: Harvard University Press.
• Mivart, St. George Jackson, 1871, On the Genesis of Species , London: MacMillan [available online]
• Moore, George Edward, 1903, Principia Ethica , Cambridge: Cambridge University Press. [ G.E. Moore 1903 available online ]
• Moore, James R., 1979, The Post-Darwinian Controversies: A Study of the Protestant Struggle to Come to Terms with Darwin in Great Britain and America 1870–1900 , Cambridge: Cambridge University Press. doi:10.1017/CBO9780511622830
• Mullen, Pierce C., 1964, “The Preconditions and Reception of Darwinian Biology in Germany, 1800–1870”, Unpublished Ph.D Dissertation, University of California, Berkeley.
• Newman, Stuart A., 2015, “The Evolution of Evolutionary Mechanisms”, in Sloan, McKenny, and Eggleson 2015: 61–89.
• Norman, David, 2013, “Charles Darwin’s Geology”, in Ruse 2013a: 46–55. doi:10.1017/CBO9781139026895.005
• Numbers, Ronald L., 1998, Darwinism Comes to America , Cambridge, MA: Harvard University Press.
• Olby, Robert C., 1963, “Charles Darwin’s Manuscript of Pangenesis”, The British Journal for the History of Science , 1(3): 251–263. doi:10.1017/S0007087400001497
• –––, 2013, “Darwin and Heredity”, in Ruse 2013a: 116–123. doi:10.1017/CBO9781139026895.014
• Ospovat, Dov, 1981, The Development of Darwin’s Theory: Natural History, Natural Theology, and Natural Selection , Cambridge: Cambridge University Press.
• Pancaldi, Giuliano, 1983 [1991], Darwin in Italia: Impresa scientifica e frontiere culturali , (Saggi 248), Bologna: il Mulino. Translated as Darwin in Italy: Science across Cultural Frontiers , Ruey Brodine Morelli (trans.), Bloomington: Indiana University Press, 1991.
• Peckham, Morse (ed.), 2006, The Origin of Species: a Variorum Text , Philadelphia: University of Pennsylvania Press, reprint of 1959 edition.
• Pigliucci, Massimo and Gerd Müller (eds.), 2010, Evolution, the Extended Synthesis , Cambridge, MA: MIT Press.
• Prestes, Maria Elice Brzezinski (ed.), 2023, Understanding Evolution in Darwin ’s ‘Origin’: The Emerging Context of Evolutionary Thinking , Cham: Springer.
• Provine, William B., 1971, The Origins of Theoretical Population Genetics , Chicago: University of Chicago Press.
• Pusey, James Reeve, 1983, China and Charles Darwin , (Harvard East Asian Monographs 100), Cambridge, MA: Harvard University Press.
• Radick, Gregory, 2013, “Darwin and Humans”, in Ruse 2013a: 173–181. doi:10.1017/CBO9781139026895.022
• Richards, Evelleen, 2017, Darwin and the Making of Sexual Selection , Chicago: University of Chicago Press. doi:10.7208/chicago/9780226437064.001.0001
• Richards, Richard A., 2010, The Species Problem: A Philosophical Analysis , Cambridge: Cambridge University Press. doi:10.1017/CBO9780511762222
• –––, 2013, “Sexual Selection”, in Ruse 2013a: 103–108. doi:10.1017/CBO9781139026895.012
• Richards, Robert J., 1987, Darwin and the Emergence of Evolutionary Theories of Mind and Behavior , Chicago: University of Chicago Press.
• –––, 1999, “Darwin’s Romantic Biology: The Foundation of His Evolutionary Ethics”, in J. Maienschein and M. Ruse 1999 (eds.) 1999: 113–153. doi:10.1017/CBO9780511609077.007
• –––, 2002, The Romantic Conception of Life: Science and Philosophy in the Age of Goethe , Chicago: University of Chicago Press.
• –––, 2005, “Darwin’s Metaphysics of Mind”, in Hösle and Illies 2005, 166–180.
• –––, 2008, The Tragic Sense of Life: Ernst Haeckel and the Struggle Over Evolutionary Thought , Chicago: University of Chicago Press.
• –––, 2009, “Darwin on Mind, Morals and Emotions”, in Hodge and Radick 2009: 96–119, doi:10.1017/CCOL9780521884754.005
• –––, 2013, “The German Reception of Darwin’s Theory, 1860–1945”, in Ruse 2013a: 235–242. doi:10.1017/CBO9781139026895.030
• –––, 2015, “Darwin’s Evolutionary Ethics: the Empirical and Normative Justifications”, in Sloan, McKenny and Eggleson, 2015, 182–200.
• –––, and Michael Ruse, 2016, Debating Darwin , Chicago: University of Chicago Press.
• Ruse, Michael, 1975, “Darwin’s Debt to Philosophy: An Examination of the Influence of the Philosophical Ideas of John F. W. Herschel and William Whewell on the Development of Charles Darwin’s Theory of Evolution”, Studies in the History and Philosophy of Science , 6: 159–181.
• –––, 2009a, “The Origin of the Origin ”, in Ruse and R. J. Richards 2009: 14–14. doi:10.1017/CCOL9780521870795.003
• –––, 2009b, Defining Darwin: Essays on the History and Philosophy of Evolutionary Biology , Amherst, MA: Prometheus Books.
• –––, 2009c, Philosophy After Darwin: Classic and Contemporary Readings , Princeton: Princeton University Press.
• ––– (ed.), 2013a, The Cambridge Encyclopedia of Darwin and Evolutionary Thought , Cambridge: Cambridge University Press. doi:10.1017/CBO9781139026895
• –––, 2013b, “Evolution before Darwin”, in Ruse 2013a: 39–45. doi:10.1017/CBO9781139026895.004
• –––, 2013c, “The Origin of Species ”, in Ruse 2013a: 95–102. doi:10.1017/CBO9781139026895.011
• –––, and Robert J. Richards (eds.), 2009, The Cambridge Companion to the “Origin of Species” , Cambridge: Cambridge University Press. doi:10.1017/CCOL9780521870795
• Secord, James A., 2000, Victorian Sensation: The Extraordinary Publication, Reception, and Secret Authorship of Vestiges of the Natural History of Creation , Chicago: University of Chicago Press.
• Shen, Vincent, 2016, “Translation and Interpretation: the Case of Introducing Darwinian Evolutionism into China”, Universitas: Monthly Review of Philosophy and Culture , 43: 3–25.
• Sloan, Phillip R. 1986, “Darwin, Vital Matter, and the Transformism of Species”, Journal of the History of Biology , 19 (3): 369–445. doi:10.1007/BF00138286
• –––, 1999, “From Natural Law to Evolutionary Ethics in Enlightenment French Natural History”, in Maienschein and Ruse 1999: 52–83. doi:10.1017/CBO9780511609077.004
• –––, 2009a, “The Making of a Philosophical Naturalist”, in Hodge and Radick 2009: 21–43, doi:10.1017/CCOL9780521884754.002
• –––, 2009b, “Originating Species: Darwin on the Species Problem”, in Ruse and R. J. Richards 2009: 67–86. doi:10.1017/CCOL9780521870795.007
• –––, Gerald P McKenny, and Kathleen Eggleson (eds.), 2015, Darwin in the Twenty-First Century: Nature, Humanity, and God , Notre Dame, IN: University of Notre Dame Press.
• Smocovitis, Vassiliki Betty, 1996, Unifying Biology: The Evolutionary Synthesis and Evolutionary Biology , Princeton, NJ: Princeton University Press.
• Sober, Elliott, 1984, The Nature of Selection: Evolutionary Theory in Philosophical Focus , Cambridge, MA: MIT Press.
• Spencer, Herbert, 1864, Principles of Biology , London: Williams and Noegate. [ Spencer 1864 available online ]
• Stamos, David N., 2003, The Species Problem: Biological Species, Ontology, and the Metaphysics of Biology , Lanham, MA: Lexington Books.
• –––, 2007, Darwin and the Nature of Species , Albany, NY: State University of New York Press.
• Swetlitz, Marc, 2013, “Judaism, Jews, and Evolution”, in Ruse 2013a: 493–498. doi:10.1017/CBO9781139026895.063
• Theunissen, Bert, 2013, “The Analogy between Artificial and Natural Selection”, in Ruse 2013a: 88–94. doi:10.1017/CBO9781139026895.010
• Todes, Daniel Philip, 1989, Darwin Without Malthus: the Struggle for Existence in Russian Evolutionary Thought , New York and Oxford: Oxford University Press.
• Vorzimmer, Peter J., 1970, Charles Darwin, The Years of Controversy: The Origin of Species and Its Critics, 1859–1882 , Philadelphia: Temple University Press.
• Wallace, Alfred R., 1858, “On the Tendency of Varieties to Depart Indefinitely from the Original Type”, in Glick and Kohn 1996, 335–345.
• –––,“The Origin of Human Races and the Antiquity of Man Deduced from the Theory of ‘Natural Selection’”, Journal of the Anthropological Society of London , 2: clviii–clxxxvii. doi:10.2307/3025211
• Waters, C. Kenneth, 2009, “The Arguments in the Origin of Species ”, in Hodge and Radick 2009: 120–144, doi:10.1017/CCOL9780521884754.006
• Whewell, William, 1837, History of the Inductive Sciences, from the Earliest to the Present Times , three volumes, London: Parker.
• –––, 1840, The Philosophy of the Inductive Sciences , London: Parker. [ Whewell 1840 available online ]
• –––, 1858, Novum Organon Renovatum, Being the Second Part of the Philosophy of the Inductive Sciences , thirrd edition, London: Parker. [ Whewell 1858 available online ]
• White, Roger M., M. J. S. Hodge, and Gregory Radick, 2021, Darwin’s Argument by Analogy: From Artificial to Natural Selection , Cambridge: Cambridge University Press.
• Wilkins, John S., 2009, Species: a History of the Idea , Berkeley and Los Angeles: University of California Press.
• Yang Haiyan, 2013, “Encountering Darwin and Creating Darwinism in China”, in Ruse 2013a: 250–257. doi:10.1017/CBO9781139026895.032
• Yan Fu, 1898, Tianyan lun , translation of Huxley 1895, [available online ]
• Young, Robert M., 1985, Darwin’s Metaphor: Nature’s Place in Victorian Culture , Cambridge: Cambridge University Press.

How to cite this entry . Preview the PDF version of this entry at the Friends of the SEP Society . Look up topics and thinkers related to this entry at the Internet Philosophy Ontology Project (InPhO). Enhanced bibliography for this entry at PhilPapers , with links to its database.

• The Complete Works of Charles Darwin Online , maintained by John van Wyhe, Cambridge University Library. In particular note the Darwin Papers & Manuscripts section
• Darwin Manuscripts Project , maintained by David Kohn in cooperation with the American Museum of Natural History Research Library.
• Letter to Charles Lyell, 28 September 1860, DCP-LETT-2931
• Letter from J.D. Hooker, 8 February 1867, DCP-LETT-5395
• Letter to William Turner, 11 February 1867, DCP-LETT-5398
• Letter to Asa Gray, 15 March 1870, DCP-LETT-7132
• Ghiselin, Michael T., 2009, Darwin: A Reader’s Guide [PDF], Occasional Papers of the California Academy of Sciences 155.
• The Huxley File , maintained by Charles Blinderman and David Joyce (Clark University).
• Works by Ernst Heinrich Haeckel , Project Gutenberg.
• Wallace Online , maintained by John van Wyhe, Cambridge University Library.

adaptationism | altruism | altruism: biological | animal: cognition | animal: consciousness | biology: philosophy of | comparative cognition, methods in | creationism | Darwinism | evolution: concept before Darwin | evolution: cultural | fitness | genetics: ecological | life | morality: and evolutionary biology | moral sentimentalism | natural selection | natural selection: units and levels of | Newton, Isaac: philosophy | species | Spencer, Herbert | teleology: teleological notions in biology | Whewell, William

The author wishes to acknowledge the valuable comments on this version of the article by David Depew, Gregory Radick, M. J. S. Hodge, Alan Love, and Xiaoxing Jin. Additional comments were made on an earlier version by Michael Ruse, Robert J. Richards, Edward Zalta, M. Katherine Tillman, and the anonymous reviewers for the Stanford Encyclopedia of Philosophy. I am particularly indebted to Dr. Xiaoxing Jin for information contained in his substantial doctoral work and subsequent research on the reception of Darwinism into China. Responsibility for all interpretations is my own.

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Darwinism as Religion: What Literature Tells Us About Evolution

Michael Ruse, Darwinism as Religion: What Literature Tells Us About Evolution , Oxford University Press, 2017, 310pp., $34.95 (pbk), ISBN 9780190241025.

Reviewed by Ian Hesketh, The University of Queensland

Michael Ruse is a well-known authority in the history and philosophy of evolution, particularly that of Darwinism. While he is by training and self-identification a philosopher, his particular mode of philosophy is decidedly historical in the sense that his arguments are typically developed out of an engagement with historical evidence and narrative. His first book, The Darwinian Revolution (1979), is a wonderful example of his historical-philosophical method at work as he situated the sudden rise of Darwinian evolution within the particular social, cultural, and philosophical contexts of Victorian Britain. In Monad to Man (1996), Ruse extended his history of evolution into the twentieth century while exploring the centrality of progressivism in evolutionary thought, thereby highlighting some of the metaphysical issues that were essential to the popularization of evolution, and which were eventually suppressed by a professionalizing biology in the second half of the twentieth century. Darwin, of course, is the dominant figure in this book as well, with Ruse arguing that, in contrast to many modern assumptions about Darwinian evolution, progress was an important aspect of Darwin's whole scheme of evolution by natural selection. While several other of Ruse's books could be mentioned in this context, I think it is fruitful to think of his new book as continuing, deepening, and extending an argument about the central Darwinian nature of evolution that runs throughout these two earlier works. And, in its own way, it is equally important as these two now classic studies.

Before getting into the details, it is worth mentioning that Ruse's general thesis about the "Darwinian" revolution tends to run afoul of recent historiographical approaches to the subject. Part of the issue is that in recent years historians of science have sought to downplay the role of scientific heroes like Darwin in favor of lesser-known figures whose work was apparently more influential than previously thought. Bernard Lightman, for instance, has shown that many of the most popular writers of evolution in the Victorian period were motivated by and engaged with evolutionary theories produced not by Darwin but rather by Lamarck, by the anonymous author of the Vestiges of the Natural History of Creation (1844), or by Herbert Spencer. [1] And Lightman's work is complementary to the very anti-Rusean thesis put forward by Peter Bowler, who argues that Darwin's particular theory of evolution by natural selection was never really embraced by the vast majority of evolutionists, who preferred the more teleological and progressive theories produced by one or more of Darwin's competitors. It is better to think of the nineteenth and early twentieth centuries, Bowler argues, as defined by a "non-Darwinian Revolution," referring to the wide-acceptance of what he designates "developmental" theories of evolution at the expense of the specifically Darwinian. [2] In his more recent, counterfactual study, Bowler makes the bold claim that had Darwin died on his famous Beagle voyage, the science of evolution would have developed more or less as it did, if not quicker and much less contentiously. [3]

Understandably the author of the Darwinian Revolution is not a fan of the "non-Darwinian Revolution" (56, 67-68). [4] And Ruse's Darwinism as Religion can therefore be read as a challenge to this recent turn in the historiography of evolution as well as a defense of his own earlier studies. This is apparent from the book's opening pages, where Ruse states: "I shall argue that Darwin is a key figure in my story and thus, in this respect, there was absolutely, totally, and completely a 'Darwinian Revolution'" (x). But what sets this book apart from Ruse's previous studies of Darwinian evolution is that the evidence mobilized in defense of his thesis comes not from the writings, theories, and views of scientists, but from literature. As is announced in the subtitle, this is a book about what literature tells us about evolution. And by literature Ruse primarily means Anglophone novels and poetry, ranging from eighteenth-century figures such as Alexander Pope, Erasmus Darwin, and William Godwin, through to nineteenth-century writers such as George Eliot, Elizabeth Gaskell, Alfred Tennyson, and Emily Dickinson, and on to more recent authors such as William Golding, Ian McEwan, and Marilynne Robinson. These are just a few of the writers discussed in what is an incredibly wide-ranging analysis that foregrounds Ruse's uncanny ability to find relevant evolutionary meanings in seemingly innocuous passages of literature.

The conceptual apparatus is largely borrowed from Monad to Man , in which Ruse tracked the development of Darwinian evolution from a pseudoscience to a popular science to a professional science. The vast majority of the book, however, focuses on Darwinism as popular science, that is to say from the publishing of Darwin's Origin of Species in 1859 to the early twentieth century. What Ruse shows is that during this period many, many authors from a variety of religious and political perspectives, "wrestled" (a favorite metaphor of his) with the implications of Darwinian evolution because it necessarily undermined the stable world that had been made coherent and unambiguous by Christianity. It is in the realm of such literature, argues Ruse, that one gets at the extent to which evolution had permeated the popular imagination while gaining insight into the transformative impact Darwin had on human self-understanding.

So after establishing the singular contribution Darwin made to the development of evolution, Ruse explores the influence of that contribution on literature in chapters devoted to the respective themes of God, origins, humans, race and class, morality, sex, sin and redemption, and the future. By thoroughly naturalizing human origins, Darwin undermined the stability of meaning that had been provided by Christianity in all of these realms of thought. For the writer Thomas Hardy, for instance, an evolutionary perspective meant that humans were not God's favored creation, and therefore under His care and protection, but the mere products of nature, and therefore entirely under the subjection of its whims. This issue is explored in Tess of the D'Ubervilles (1892), which is about a woman, the title character, who is fundamentally a good person, although this does not save her from being imprisoned and then executed. Tess's moral intentions, therefore, are entirely divorced from her ultimate fate. For Ruse, this is one prominent interpretation of Darwinism, namely that "We are in a world of chance, of fate, where humans -- no matter their stunning beauty, their moral purity -- count for naught" (127). There is indeed a bleakness in Hardy's Darwinian universe. But, as Ruse argues, this was not necessarily the only way to live in Darwin's world.

The novelist Charles Kingsley, for one, found Darwinian evolution complementary to his Christian socialism. His popular Water Babies (1863) was a children's story about Tom, a chimney sweep who drowns and turns into a "water baby." Despite this degeneration, Tom again becomes human as he "slowly matures morally, learning to do things he does not like because they are the right thing to do" (90). Under Ruse's reading, therefore, The Water Babies is an evolutionary tale that is embedded in a larger narrative of Christian redemption. For Kingsley, Darwinian evolution could accommodate a moral scheme derived from Christianity, which helps explain why he was such an enthusiastic proponent of evolution.

Hardy and Kingsley represent opposite ends of a wide spectrum that includes a whole host of diverse responses to Darwinian evolution, from those advocating some sort of transcendental evolutionism such as Emily Dickinson to the deeply ambivalent "despair in the face of Godless nothingness" that was typical of Joseph Conrad (136). Darwin, Ruse argues, quite simply "changed our world," and this was the case "for those who agreed with him fully, for those who agreed with him but partially, and for those who rejected his thinking in various ways" (x). In other words, there was no escaping the Darwinian revolution for anyone, for proponents or critics alike who had to wrestle with the world that Darwin created.

If the vast literary responses to Darwinism convince Ruse of his original thesis about the pervasive nature of the Darwinian revolution, and therefore undermine any notion of a non-Darwinian revolution, he also wants to go beyond his original thesis, and this gets at the main title of the book. His foray into literature makes him realize that the Darwinian was not just a scientific revolution but also a revolution in how people understood themselves in relation to the world and the larger universe. It was therefore also a "religious revolution" as evolution, rather than Christianity, was now looked to in order to answer fundamental metaphysical questions, such as the meaning of life or the nature of God (281; see also 82). That Darwinism became a secular religion by ultimately replacing Christianity is a compelling and provocative claim. Moreover, Ruse uses the comparison of Darwinism to Christianity to great effect, particularly when he explains that the diversity of Darwinism was not unlike the variations that one finds within the realm of Christianity itself (see 87, 219 n. 7).

This book, then, effectively seeks to establish "Darwinism" as representative of a paradigm shift in worldview that occurs during the second half of the nineteenth century and the beginning of the twentieth century. Critics of this claim will no doubt argue that the evidence Ruse has mobilized in favor of this shift -- in the novels and poetry of the time -- leaves more room for interpretation than Ruse seems willing to acknowledge. Moreover, the quick pacing does not always lend itself to a careful analysis of the material, as Ruse clearly does not want to get bogged down by laboring a particular point or theme. An example of this occurs early on in a discussion of William Godwin's novel Things as They Are; or, The Adventures of Caleb Williams (1794), an analysis that is rather suddenly halted by the sentence "Enough!" (7). I read this as a humorous warning to readers that they should not expect extended summaries of plots or intricate deep readings of excerpted prose. But, as an authority no less than Dame Gillian Beer, author of Darwin's Plots , [5] points out on the back cover, this is not an academic book of literary criticism. What it is, rather, is "an intensely personal reading of deep questions that have preoccupied writers, and people at large, over the last hundred and fifty years." Indeed, Ruse's book  is an absolute joy to read and to ponder. It is a witty and, at times, polemical work that pursues a provocative and thought-provoking thesis that is by definition almost impossible to prove. To put it another way, it is a book that could have been written only by Michael Ruse. And that is indeed a good thing.

[1] Bernard Lightman, Victorian Popularizers of Science : Designing Nature for New Audiences (University of Chicago Press, 2007); Lightman, "Darwin and the Popularization of Evolution," Notes and Records of the Royal Society of London 64:1 (2010): 5-24; and Lightman (ed.), Global Spencerism: The Communication and Appropriation of a British Evolutionist (Brill, 2015).

[2] Peter Bowler, The Non-Darwinian Revolution: Reinterpreting a Historical Myth (Johns Hopkins University, 1988).

[3] Peter Bowler, Darwin Deleted: Imagining a World without Darwin (University of Chicago Press, 2013).

[4] See also Piers Hale, "Rejecting the Myth of the Non-Darwinian Revolution," Victorian Review 41:1 (Fall 2015), for a critique of the "non-Darwinian" concept.

[5] Gillian Beer, Darwin's Plots: Evolutionary Narrative in Darwin, George Eliot, and Nineteenth-Century Fiction (Cambridge University Press, 1983).

The Darwinian Revolution Revisited

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• Volume 38 , pages 51–66, ( 2005 )

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The “Darwinian revolution” remains an acceptable phrase to describe the change in thought brought about by the theory of evolution, provided that the revolution is seen as occurring over an extended period of time. The decades from the 1790s through the 1850s are at the focus of this article. Emphasis is placed on the issue of species extinction and on generational shifts in opinion.

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Louis Aggasiz (1842) ArticleTitle “On the Succession and Development of Organized Beings at the Surface of the Terrestrial Globe.” Edinburgh New Philosophical Journal 33 388–399

Google Scholar  

Toby A. Appel (1987) The Cuvier–Geoffroy Debate: French Biology in the Decades before Darwin Princeton University Press Princeton

Peter Bowler (1988) The Non-Darwinian Revolution: Reinterpreting a Historical Myth Johns Hopkins University Baltimore

Janet Browne (1983) The Secular Art: Studies in the History of Biogeography Yale University Press New Haven

Janet Browne (1995) Charles Darwin: Voyaging Alfred A. Knopf New York

Janet Browne (2002) Charles Darwin: The Power of Place Alfred A. Knopf New York

Burkhardt, Frederick et al. (ed.). 1985-. The Correspondence of Charles Darwin. 13+ vols . Cambridge: Cambridge University Press. Abbreviation: Correspondence

Richard W. Burkhardt Suffix Jr. (1972) ArticleTitle “The Inspiration of Lamarck’s Belief in Evolution.” Journal of the History of Biology 5 413–438 Occurrence Handle 10.1007/BF00346666

Article   Google Scholar  

Burkhardt, Richard W., Jr. 1995. The Spirit of System: Lamarck and Evolutionary Biology , 2nd ed. Cambridge: Harvard University Press

I. Bernard Cohen (1985) Revolution in Science Harvard University Press Cambridge

William Coleman (1964) George Cuvier, Zoologist: A Study in the History of Evolution-Theory Harvard University Press Cambridge Occurrence Handle 10.4159/harvard.9780674283701

Book   Google Scholar  

Yvette. Conry (1974) L’Introduction du Darwinisme en France au XIX e siècle Vrin Paris

Pietro Corsi (1988a) Science and Religion: Baden Powell and the Anglican Debate, – 1800–1860 Cambridge University Press Cambridge Occurrence Handle 10.1017/CBO9780511598494

Pietro Corsi (1988b) The Age of Lamarck: Evolutionary Theories in France, 1790–1830 University of California Press Berkeley

Charles Darwin (1859) On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life John Murray London

De Beer, Gavin. 1960. “Darwin’s Notebooks on Transmutation of Species.” Bulletin of the British Museum (Natural History) Historical Series 2 (2–5).

De Beer, Gavin, Rowlands M.J. and Skramovsky, B.M. 1967. “Darwin’s Notebooks on Transmutation of Species: Pages Excised by Darwin.” Bulletin of the British Museum (Natural History) Historical Series 3 (5).

Frank N. Egerton (2003) Hewett Cottrell Watson: Victorian Plant Ecologist and Evolutionist Ashgate England, Aldershot

Loren Eiseley (1958) Evolution and the Men Who Discovered It Doubleday & Co Garden City, NY

Paul Lawrence Farber (2000) Finding Order in Nature: The Naturalist Tradition from Linnaeus to E. O. Wilson Johns Hopkins University Press Baltimore, MD

Frängsmyr, Tore (ed.). 1994. Linneaus: The Man and His Work , 2nd ed. Canton, MA: Science History Publications

Michael T. Ghiselin (1969) The Triumph of the Darwinian Method University of California Press Berkeley

Charles Coulston Gillispie (1989) ArticleTitle “Scientific Aspects of the French Egyptian Expedition, 1798–1801.” Proceedings of the American Philosophical Society 133 447–474

Glick, Thomas F. (ed.). 1974. The Comparative Reception of Darwinism , 2nd ed. 1988. Chicago: University of Chicago Press

Stephen J. Gould (1979) ArticleTitle “Agassiz’s Marginalia in Lyell’s Principles, or the Perils of Uniformity and the Ambiguity of Heroes.” Studies in History of Biology 3 119–138

Judith V. Grabiner D. Miller Peter (1974) ArticleTitle “Effects of the Scopes Trial.” Science 187 IssueID 6 September 832–837 Occurrence Handle 10.1126/science.185.4154.832

Greene, John C. 1959. The Death of Adam: Evolution and Its Impact on Western Thought , 2nd ed. 1996. Ames: Iowa State University Press

John C. Greene (1971) “The Kuhnian Paradigm and the Darwinian Revolution in Natural History.” H.D. Roller Duane (Eds) Perspectives in the History of Science and Technology University of Oklahoma Press Norman

Howard E. Gruber H. Barrett Paul (1974) Darwin on Man: A Psychological Study of Scientific Creativity together with Darwin’s Early and Unpublished Notebooks E. P. Dutton New York

Joy Harvey (1997) “Almost a Man of Genius”: Clémence Royer: Feminism, and Nineteenth-Century Science Rutgers University Press New Brunswick

Herbert, Sandra. 1968. “The Logic of Darwin’s Discovery.” Brandeis University, Ph.D. Dissertation.

Herbert, Sandra. 1974, 1977. “The Place of Man in the Development of Darwin’s Theory of Transmutation, Parts I and II.” Journal of the History of Biology 7: 217–258, 10: 155–227

Sandra Herbert (1980) The Red Notebook of Charles Darwin. Bulletin of the British Museum (Natural History) Historical Series. 7 Cornell University Press Ithaca

Sandra Herbert (2005) Charles Darwin, Geologist Cornell University Press Ithaca

Jonathan Hodge (1983) ArticleTitle “Darwin and the Laws of the Animate Part of the Terrestrial System (1835–1837): On the Lyellian Origins of His Zoonomical Explanatory Program.” Studies in History of Biology 6 1–106

Hofstadter, Richard. 1955. Social Darwinism in American Thought , Rev. ed. Boston: Beacon Press

David L. Hull (1973) Darwin and His Critics: The Reception of Darwin’s Theory of Evolution by the Scientific Community Harvard University Press Cambridge

Richard Darwin Keynes (2000) Darwin’s Zoology Notes and Specimen Lists from H.M.S. Beagle Cambridge University Press Cambridge

Desmond King-Hele (1999) Erasmus Darwin: A Life of Unequalled Achievement Giles de la Mare Publishers London

David Kohn (1980) ArticleTitle “Theories to Work By: Rejected Theories, Reproduction, and Darwin’s Path to Natural Selection.” Studies in History of Biology 4 67–170

David Kohn (Eds) (1985) The Darwinian Heritage. With Bibliographic Assistance from Malcolm J Kottler Princeton University Press Princeton

Hervé. Le Guyader (2004) Geoffroy Saint-Hilaire: A Visionary Naturalist. Trans. Marjorie Grene University of Chicago Press Chicago

Camille Limoges (1970) La sélection naturelle Presses universitaires de France Paris

José M. LópezPiñero (1988) ArticleTitle “Juan Bautista Bru (1740–1799) and the Description of the Genus Megatherium.” Journal of the History of Biology 21 147–163 Occurrence Handle 10.1007/BF00125797

Charles Lyell (1832) Principles of Geology, Being An Attempt to Explain the Former Changes of the Earth’s Surface, by Reference to Causes Now in Operation. Volume 2 John Murray London

Thomas Robert Malthus (1959) Population: The First Essay [1798] University of Michigan Press Ann Arbor

Edward Manier (1978) The Young Darwin and His Cultural Circle Reidel Dordrecht Occurrence Handle 10.1007/978-94-009-9797-4

Frank E. Manuel (Eds) (1965) The Enlightenment Prentice-Hall Englewood Cliffs

Ernst Mayr (1982) The Growth of Biological Thought: Diversity, Evolution, and Inheritance Harvard University Press Cambridge

Ospovat, Dov. 1981. The Development of Darwin’s Theory: Natural History, Natural Theology and Natural Selection, 1838–1859 . Cambridge: Cambridge University Press. (reissue 1995).

Dorinda Outram (1984) Georges Cuvier: Vocation, Science, and Authority in Post-Revolutionary France Manchester University Press Manchester

Philip H. Rehbock (1983) The Philosophical Anatomists University of Wisconsin Press Madison

Robert J. Richards (1987) Darwin and the Emergence of Evolutionary Theories of Mind and Behavior University of Chicago Press Chicago

Robert J. Richards (2002) The Romantic Conception of Life: Science and Philosophy in the Age of Goethe University of Chicago Press Chicago Occurrence Handle 10.7208/chicago/9780226712185.001.0001

Marsha L. Richmond (2001) ArticleTitle “Women in the Early History of Genetics: William Bateson and the Newnham College Mendelians, 1900–1910.” Isis 91 55–90 Occurrence Handle 10.1086/385040

Martin J.S. Rudwick (1972) The Meaning of Fossils: Episodes in the History of Palaeontology Macdonald London

Martin J.S. Rudwick (1997) Georges Cuvier, Fossil Bones, and Geological Catastrophes: New Translations and Interpretations of the Primary Texts University of 1997 Chicago Occurrence Handle 10.7208/chicago/9780226731087.001.0001

Ruse, Michael. 1979. The Darwinian Revolution: Science Red in Tooth and Claw . 2nd ed. 1999. Chicago: University of Chicago Press

Michael Ruse (1996) Monad to Man: The Concept of Progress in Evolutionary Biology Harvard University Press Cambridge

Phillip R. Sloan (Eds) (1992) The Hunterian Lectures in Comparative Anatomy by Richard Owen University of Chicago Press Chicago

E.C. Spary (2000) Utopia’s Garden: French Natural History from the Old Regime to Revolution University of Chicago Press Chicago Occurrence Handle 10.7208/chicago/9780226768700.001.0001

Robert C. Stauffer (1975) Charles Darwin’s Natural Selection: Being the Second Part of His Big Species Book Written from 1856 to 1858 Cambridge University Press Cambridge

Frank Sulloway (1982) ArticleTitle “Darwin’s Conversion: The Beagle Voyage and Its Aftermath.” Journal of the History of Biology 15 327–398

Stephen Toulmin Goodfield June (1965) The Discovery of Time Harper & Row New York

Jenny Uglow (2002) The Lunar Men: Five Friends Whose Curiosity Changed the World Farrar, Straus and Giroux New York

Alfred Russel Wallace (1889) Darwinism: An Exposition of the Theory of Natural Selection with Some of Its Applications Macmillan London

Samuel Wilberforce (1860) ArticleTitle “On the Origin of Species . . . by Charles Darwin.” Quarterly Review 108 225–264

Virginia Woolf (1967) Collected Essays, 4 vols Harcourt, Brace, and World New York

Robert M. Young (1969) ArticleTitle “Malthus and the Evolutionists: The Common Context of Biological and Social Theory.” Past and Present 43 109–145 Occurrence Handle 10.1093/past/43.1.109

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Herbert, S. The Darwinian Revolution Revisited. J Hist Biol 38 , 51–66 (2005). https://doi.org/10.1007/s10739-004-6509-y

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AP®︎/College Biology

Course: ap®︎/college biology   >   unit 7.

• Introduction to evolution and natural selection
• Natural selection and the owl butterfly
• Biodiversity and natural selection
• Variation in a species

Darwin, evolution, & natural selection

Natural selection, key points:.

• Charles Darwin was a British naturalist who proposed the theory of biological evolution by natural selection.
• Darwin defined evolution as "descent with modification," the idea that species change over time, give rise to new species, and share a common ancestor.
• The mechanism that Darwin proposed for evolution is natural selection . Because resources are limited in nature, organisms with heritable traits that favor survival and reproduction will tend to leave more offspring than their peers, causing the traits to increase in frequency over generations.
• Natural selection causes populations to become adapted , or increasingly well-suited, to their environments over time. Natural selection depends on the environment and requires existing heritable variation in a group.

What is evolution?

Early ideas about evolution, influences on darwin, darwin and the voyage of the beagle.

• Traits are often heritable. In living organisms, many characteristics are inherited, or passed from parent to offspring. (Darwin knew this was the case, even though he did not know that traits were inherited via genes.) A diagram with text reading parents pass on heritable traits to their offspring. On the left a dark blue and a light blue butterfly are crossed to produce offspring with wings of varying shades of blue. On the right a dark red and a light red butterfly are crossed to produce offspring with wings of varying shades of red.
• More offspring are produced than can survive. Organisms are capable of producing more offspring than their environments can support. Thus, there is competition for limited resources in each generation. A diagram with a box reading limited resources. Arrows point away from the box to bubbles reading lack of food, lack of habitat, and lack of mates. Text below reads …not all individuals will survive and reproduce. A group of 16 butterflies with wings of varying shades of blue and red is shown. A text bubble reading gleep! comes from 4 of the butterflies.
• Offspring vary in their heritable traits. The offspring in any generation will be slightly different from one another in their traits (color, size, shape, etc.), and many of these features will be heritable. A group of 16 butterflies with wings of varying shades of blue and red is shown. A text bubble reading Hey, are you red? That's pretty sweet! comes from one of the blue butterflies. A text bubble reading Whoa! Love that blue wing color comes from one of the red butterflies. Text at the bottom reads Butterflies do not actually talk! Cartoon for cute illustration purposes only. A smiley face is shown next to the text.
• In a population, some individuals will have inherited traits that help them survive and reproduce (given the conditions of the environment, such as the predators and food sources present). The individuals with the helpful traits will leave more offspring in the next generation than their peers, since the traits make them more effective at surviving and reproducing.
• Because the helpful traits are heritable, and because organisms with these traits leave more offspring, the traits will tend to become more common (present in a larger fraction of the population) in the next generation.
• Over generations, the population will become adapted to its environment (as individuals with traits helpful in that environment have consistently greater reproductive success than their peers).

Example: How natural selection can work

Key points about natural selection, natural selection depends on the environment, natural selection acts on existing heritable variation, heritable variation comes from random mutations, natural selection and the evolution of species, attribution:, works cited:.

• Wilkin, D. and Akre, B. (2016, March 23). Influences on Darwin - Advanced. In CK-12 biology advanced concepts . Retrieved from http://www.ck12.org/book/CK-12-Biology-Advanced-Concepts/section/10.18/ .
• Reece, J. B., Urry, L. A., Cain, M. L., Wasserman, S. A., Minorsky, P. V., and Jackson, R. B. (2011). The voyage of the Beagle . In Campbell Biology (10th ed., p. 466). San Francisco, CA: Pearson.
• Darwin's finches. (2016, April 25). Retrieved March 16, 2016 from Wikipedia: https://en.wikipedia.org/wiki/Darwin%27s_finches .
• Reece, J. B., Urry, L. A., Cain, M. L., Wasserman, S. A., Minorsky, P. V., and Jackson, R. B. (2011). Figure 1.18. Natural selection. In Campbell biology (10th ed., p. 14). San Francisco, CA: Pearson.

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September 1, 2015

Copernicus, Darwin and Freud: A Tale of Science and Narcissism

Freud did not originate his famous description of Copernicus and Darwin as deflators of humanity's anthropomorphic world-view.

By John Horgan

This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American

In a recent column I wrote : “In spite of all the blows dealt to our egos by science—beginning with the demonstration that the Sun and not the Earth is the center of the Solar System—many of us remain convinced that this universe was created for us, and that our destiny is unfolding according to a pre-ordained divine plan.”

The notion that heliocentrism was a blow to humanity’s narcissism is commonly attributed to Freud. But after reading my column, my buddy Gabriel Finkelstein, a historian of science at the University of Colorado, Denver, informed me that Freud got the idea from the 19th-century German physiologist-polymath Emil du Bois-Reymond, about whom Gabriel wrote a terrific biography. ( See this 2013 interview with Gabriel about his book .) As Gabriel details below, Freud was well aware of du Bois-Reymond’s work, as were other pioneers of mind-science. But first, consider this quote from Freud’s A General Introduction to Psychoanalysis (delivered as lectures 1915-1917 and first translated into English in 1920):

“Humanity has in the course of time had to endure from the hands of science two great outrages upon its naive self-love. The first was when it realized that our earth was not the center of the universe, but only a tiny speck in a world-system of a magnitude hardly conceivable; this is associated in our minds with the name of Copernicus, although Alexandrian doctrines taught something very similar. The second was when biological research robbed man of his peculiar privilege of having been specially created, and relegated him to a descent from the animal world, implying an ineradicable animal nature in him: this transvaluation has been accomplished in our own time upon the instigation of Charles Darwin, Wallace, and their predecessors, and not without the most violent opposition from their contemporaries. But man's craving for grandiosity is now suffering the third and most bitter blow from present-day psychological research which is endeavoring to prove to the ‘ego’ of each one of us that he is not even master in his own house, but that he must remain content with the veriest scraps of information about what is going on unconsciously in his own mind. We psychoanalysts were neither the first nor the only ones to propose to mankind that they should look inward; but it appears to be our lot to advocate it most insistently and to support it by empirical evidence which touches every man closely.”

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I love how Freud narcissistically suggests that his blow to our narcissism is mightier than those delivered by Copernicus and Darwin. Now compare Freud’s comments to the eulogy, “Darwin and Copernicus,” that du Bois-Reymond gave in Berlin after Darwin’s death of Darwin in 1882 (reprinted in Nature in 1883):

“Darwin seems to me to be the Copernicus of the organic world. In the sixteenth century Copernicus put an end to the anthropocentric theory by doing away with the Ptolemaic spheres and bringing our earth down to the rank of an insignificant planet. At the same time he proved the non-existence of the so-called empyrean, the supposed abode of the heavenly hosts, beyond the seventh sphere, although Giordano Bruno was the first who actually drew the inference. Man, however, still stood apart from the rest of animated beings— not at the top of the scale, his proper place, but quite away, as a being absolutely incommensurable with them. One hundred years later Descartes still held that man alone had a soul, and that beasts were mere automata… [After On the Origin of Species ] all things were seen to be due to the quiet development of a few simple germs; graduated days of creation gave place to one day on which matter in motion was created; and organic suitability was replaced by a mechanical process, for as such we may look on natural selection, and now for the first time man took his proper place at the head of his brethren… Though many links are still missing, we may fairly consider the knowledge of the existence of primeval man as the beginning of the long-looked-for connection between him and the anthropoids on the one hand, and between them both and their common progenitors on the other.”

Finkelstein adds the following comments on du Bois-Reymond’s influence on Freud and others:

“Freud planned to study with du Bois-Reymond but never made it to Berlin. Instead, he studied in Vienna with the professor of physiology at that university, Ernst von Brücke, who was du Bois-Reymond's best friend. Brücke was another mechanist physiologist (like du Bois-Reymond) from Berlin who had trained with Johannes Mülller; as students in 1842 he and du Bois-Reymond swore their famous pact to reject vitalist explanations in biology. Freud read du Bois-Reymond's popular essays on science and culture, including ‘Darwin and Copernicus,’ du Bois-Reymond's short obituary address, which was the source of Freud's trope.

“William James actually did make it to Berlin in 1867 to study neurophysiology with du Bois-Reymond, but he couldn't hack it and quit his studies. He also chafed under du Bois-Reymond's mechanism, and most of his early essays refer to du Bois-Reymond in some way. Wundt didn't study with du Bois-Reymond, but he did with his other close Berlin friend, Hermann von Helmholtz, who started his career in Berlin as another mechanist physiologist. Finally, Pavlov didn't study with du Bois-Reymond, but was inspired by du Bois-Reymond's student, Ivan Sechenov, sometimes called the father of Russian physiology. Sechenov discovered neural inhibition in 1863 in du Bois-Reymond's lab. So du Bois-Reymond had a direct or indirect influence on the four founders of the discipline of psychology. All from a guy who said that we would never understand the mind" (see Addendum ).

Finkelstein says that—to be fair to Freud--du Bois-Reymond “got most of his good ideas from people before him. I guess the moral is a) good ideas are timeless b) it's very hard to come up with anything new.”

Addendum : I didn’t get my idea for my book The End of Science from du Bois-Reymond, but I should have, because he wrote extensively—and presciently—about the limits of science. For more on his career, see Emil du Bois-Reymond: Neuroscience, Self, and Society in Nineteenth-Century Germany , by Gabriel Finkelstein. MIT Press. Also check out his 1874 essay “ Limits of Our Knowledge of Nature ,” The Popular Science Monthly . It spells out what philosopher Owen Flanagan has dubbed the mysterian perspective, which holds that consciousness is not solvable. 141 years later, mysterianism is as viable as ever.

In the Light of Evolution: Volume III: Two Centuries of Darwin (2009)

Chapter: 14 the darwinian revolution: rethinking its meaningand significance--michael ruse, 14 the darwinian revolution: rethinking its meaning and significance.

MICHAEL RUSE

The Darwinian revolution is generally taken to be one of the key events in the history of Western science. In recent years, however, the very notion of a scientific revolution has come under attack, and in the specific case of Charles Darwin and his Origin of Species there are serious questions about the nature of the change (if there was such) and the specifically Darwinian input. This chapter considers these issues by addressing these questions: Was there a Darwinian revolution ? That is, was there a revolution at all? Was there a Darwinian revolution? That is, what was the specific contribution of Charles Darwin? Was there a Darwinian revolution ? That is, what was the conceptual nature of what occurred on and around the publication of the Origin ? I argue that there was a major change, both scientifically and in a broader metaphysical sense; that Charles Darwin was the major player in the change, although one must qualify the nature and the extent of the change, looking particularly at things in a broader historical context than just as an immediate event; and that the revolution was complex and we need the insights of rather different philosophies of scientific change to capture the whole phenomenon. In some respects, indeed, the process of analysis is still ongoing and unresolved.

Department of Philosophy, Florida State University, Tallahassee, FL 32306.

T hirty years ago I (Ruse, 1979) published a book with the main title The Darwinian Revolution . No one questioned whether or not I had a real topic. There was a Darwinian revolution and my book was about it. Today, one could not be so sure. The idea of scientific revolutions has been questioned; Darwin’s contribution has been challenged; and even if you can come up positively on these matters, what on earth are we talking about anyway? These are the 3 questions I shall address in this article.

WAS THERE A DARWINIAN REVOLUTION?

Historian Jonathan Hodge (2005) has been one of the strongest naysayers on this matter. He thinks that the whole talk of scientific revolutions, something of an obsession by many historians and philosophers of science in the years after Thomas Kuhn’s engaging and influential The Structure of Scientific Revolutions (1962), is deeply misleading. The term is obviously taken by analogy from politics and even there it is doubtful that there are such things (at least that there are such things with common features) and in science likewise we have no reason to think that there are such things with common features. In any case, the talk is wrong-headed because it drives you to concentrate on some people and events and downplay or ignore other people and events.

In response, let us agree at once that focusing on revolutions (in science) does rather skew things in certain ways. Dwelling at length on Darwin carries the danger of ignoring the contributions of others in the 19th century, from the Naturphilosophen (people like the German anatomist Lorenz Oken who saw homologies everywhere) at the beginning to the orthogeneticists (people like the American paleontologist Henry Fairfield Osborn who thought that evolution has a momentum that carries it beyond adaptive success) at the end. Worse, it gives the impression that unless you have something dramatic and crisis-breaking, the science is of little value. Remember, the alternative to Kuhn’s revolutionary science is normal science, and this has (a perhaps undeserved) reputation of a 3-hour sermon by a Presbyterian minister on a wet Sunday in Scotland.

Against this, however, one can point out that the history of science as a professional discipline is little more than 50 years old and that you have to start somewhere. In the case of Darwin, even 30 years ago there was no real synthesis. The tragedy would have been if historians of science had stopped there and gone no further. But this is clearly not true. In the past 30 years or more, staying just with the history of evolutionary thinking, there has been a huge amount of work on people before and after Darwin, and on his contemporaries like Thomas Henry Huxley [for instance, Desmond (1999)]. To name but 3 researchers, one can pick out Robert J. Richards

(1987, 1992, 2002, 2008b) and the work he has done on German evolutionary thinking in the 19th century, before and after Darwin; Peter Bowler (1976, 1984, 1988, 1996), who started with paleontology in the 18th century and since has written extensively on the post-Darwinian figures in the 19th century, now extending his grasp into the 20th century; and William Provine (1971, 1986), who has offered detailed and brilliant analyses of the impact of genetics on the understanding of evolution. It just has not been the case that focusing first on Darwin led us to an inescapable dead end with respect to the rest of evolution’s history.

Should we nevertheless persist with the term “revolution”? Well, it surely depends on the case to be made. Obviously we can legitimately use the term revolution somewhat generically in politics. No one thinks the American Revolution and the French Revolution were the same, but they did share characteristics that, for example, the move from Ronald Reagan as president to George H. W. Bush did not. There was a break from the old government and this was done by a group seizing power, leading to dramatic changes. I see no reason we should not extend the term metaphorically. Think of the technological revolution in the past 20 years or so. Laptop computers are commonplace, electronic use of libraries is the norm, and search engines like Google and Yahoo have transformed the gathering of information. If this does not all add up to a revolution of some kind, it is hard to know what does. There is as much of a break with the past as there was for an American ruled from Washington rather than London. At an immediate level, the change is probably even greater.

So if you want to extend the term revolution to science, if it captures something of what goes on, then all power to the use. But now the question is whether the Darwinian revolution merits the use. Was there a big break with the past, sufficiently significant to speak of revolution? Did something big, really big, happen around 1859, and does it still merit a special place in the history of evolutionary thought? In respects, our appreciation of what happened is even greater than it was 30 years ago: If you like, today in 2009 the 200th anniversary of Darwin’s birth as opposed to 1982, the 100th anniversary of Darwin’s death. Daniel Dennett (1995) has referred to Darwin’s idea about natural selection as the greatest ever. One could debate this (Plato’s theory of forms gives it a good run for its money), but all will certainly agree that something really big happened around and because of the Origin in 1859 (Darwin, 1859). But here, let us take note of some of Hodge’s worries. The basic question is: What are we talking about? In the Darwinian case there are 2 levels of activity and interest. Without pretending that the divisions are completely simon-pure, there is the level of science and the level of metaphysics (recognizing that this includes things that might be considered scientific at one end and religious or otherwise ideological at the other end).

On one hand, there is the scientific theory of evolution through natural selection, the central topic of the Origin . On the other hand, there is what scholars like Robert M. Young (1985), borrowing a title from Thomas Henry Huxley (1863), used to refer to as the debate over “man’s place in nature.” While today we would never dare to use that kind of language, in essence they got it absolutely right. At some level, the Darwinian revolution destroyed forever the old picture of humans as somehow miraculously special, symbolically and literally as touched by magic. Admittedly, to this day Christian fundamentalists (and those of other religions) refuse to accept this, but it is true. Even if you think that you can still be religious, a Christian even, you have to rethink dramatically, emotionally even more than intellectually, what it means to be a human. Starting with a certain modesty about ourselves (Ruse, 2001).

It is hard to know how one would respond to someone who questioned the significance of the changes at either of these 2 levels. At the level of science, changing over to the idea of evolution in itself is a massive change to make, whether you are moving from a Greek theory of eternal life without change or a more Christianized vision of the instantaneous appearance of life. And then you add in the mechanism of natural selection, used by at least 90% of today’s evolutionists, and you have an even greater break with the pre- Origin past. At the level of metaphysics, the change is yet deeper if that is possible. The violent opposition of the American above-mentioned fundamentalists or creationists shows that if anything could. It is not just a question of who we are but also of how we should live our lives (Ruse, 2005). Although it is hardly the only factor, Darwinian thinking is at the center of the move to modernism, in some broad sense. Are we still to be subject to the old ways (women inferior, gays persecuted, abortion banned) or are we to look forward to a truly post-Enlightenment world, with reason and evidence making the running in an entirely secular fashion?

Grant then that something big did happen. But are we right in putting it all on 1859 and the publication of the Origin of Species ? This raises my second big question. Divide the answer according to the levels of inquiry.

WAS THERE A DARWINIAN REVOLUTION? SCIENCE

Start with one indubitable fact. There always have been and there always will be people who think that not only was Alfred Russel Wallace, the codiscoverer of natural selection, unappreciated but that Charles Darwin pinched all of the good ideas from the younger evolutionist. It should be called the Wallacean revolution with Charles Darwin but a minor footnote. [Brackman (1980) is the classic exemplification.] There

are other candidates for the job. Edward Blyth, an English-born Indian naturalist, has long been a popular name. [Eiseley (1958) was the source for this one.] More recently, in an award-winning book, James Secord (2000) argued that really it was Robert Chambers, the anonymous Scottish author of the Vestiges of the Natural History of Creation (Chambers, 1844), who did the heavy lifting. Darwin came along at the end to inherit all of the glory. (Try www.darwin-legend.org for a cross-sample of these sorts of charges.)

There is little need to spend much time on these claims because basically they don’t hold much water. Let it be shouted out loud. Darwin did not steal from Wallace. Darwin’s ideas—the ideas of the Origin that is—are all right there in the 35-page Sketch of his ideas that he wrote in 1842 (Darwin and Wallace, 1958). There was some tweaking about the nature of adaptation; perhaps he hit in the early 1850s on the principle of divergence—although there are certainly hints of that in the species notebooks—but the mechanisms (natural and sexual selection) are there, as is the structure of the argument of the Origin (more on this in a moment). Even some of the flowery passages, notably the final paragraph about grandeur in views of life, can be found in the early writings. Wallace certainly stimulated Darwin to get moving, but that was it. And incidentally, if you study Wallace’s essay carefully, you see differences from Darwin. Wallace, for instance, denied the pertinence of artificial selection. Wallace never had the term “natural selection.” Wallace had inclinations to group selection in a way absent from the Origin or earlier writings. This is not to belittle Wallace. Not at all! But he was not Charles Darwin.

The claims of others can be dismissed as well. Before Darwin, there were several people who had thoughts of natural selection and we know that he read some of them. For instance, in a pamphlet by the breeder John Sebright, there is an explicit reference to the force of natural selection, a reference that stimulated Darwin to underline the words and make a comment in the margin (Ruse, 1975a). But there is no real question that these people sparked full evolutionary thoughts in Darwin, and generally the last thing they wanted to do was use natural selection to promote evolution. Edward Blyth (1835), with whom Darwin was to have very cordial and helpful correspondence (he actually drew Darwin’s attention to an important earlier essay by Wallace) explicitly denied that his thinking had evolutionary implications. And as far as others were concerned, preDarwinian (that is pre- Origin ) evolutionists in particular, they certainly had effects on general opinion, but not like Darwin. Chambers’s Vestiges undoubtedly took the sting out of evolution, so by the time that Darwin published, it was to a certain extent old hat, but it did not have the effect of the Origin . The same is true of others, like Herbert Spencer. For all that Spencer (1852), too, hit on the idea of selection, he always thought that

Lamarckism is the chief cause of evolutionary change, and while his thinking did influence some, including his big friend Thomas Henry Huxley, he likewise did not swing people in the way that the Origin did.

Having said all of this, however, there are some interesting questions about the extent to which the revolution was truly Darwinian. Clearly some nuanced thinking is needed, starting with the fact that there was 150 years of evolutionary thinking before Darwin, including speculations by his own grandfather Erasmus Darwin. Toward a fuller analysis, divide the history of evolutionary thinking into 3 periods (Ruse, 1996). The first period, from the early 18th century (the time of the French encyclopediast and early evolutionist Denis Diderot) to the publication of the Origin in 1859, was the time when the status of evolutionary thinking was that of a pseudo science: an emergent on the cultural value of progress. Second, from the Origin to the full incorporation of Mendelism into evolutionary thinking, say ≈1930 with the work of Ronald Fisher, J. B. S. Haldane, and Sewall Wright, evolution had the status of a popular science. There was some professional work going on, particularly in the area of phylogeny tracing, but generally evolution was a museum science, still a vehicle for thoughts of progress. Causal thinking was second-rate or (often) absent entirely. Top-quality work in biology was increasingly by young researchers who turned from phylogeny tracing to microscope-based sciences, especially cytology, and then on to genetics in the 20th century. Finally, from 1930 to the present we have a fully professional science of evolutionary biology. We entered the era of neo-Darwinism (as it was called in Britain) or the synthetic theory of evolution (as it was called in the United States).

Now, frame the discussion against the background of this 3-fold division of history. If we consider the revolution in a broad sense, from the beginning of the 18th century to the beginning of the 21st century, there are 2 major points at which we want to say that it is a Darwinian revolution. The first was in the transition from being a pseudo science to being a popular science. Before the Origin , the evidence for evolution just was not there. If you believed in evolution, you were fueled primarily by ideological reasons. It is true that people knew about homologies, the fossil record was starting to fill out, embryology was suggestive, and so forth. But the full picture was not there. After the Origin , being an evolutionist was just plain common sense. And people did become evolutionists. Even church people. With the notable exception of American evangelicals, especially in the South, evolution was accepted (Roberts, 1988). It is true that there was some backsliding, in the Catholic Church especially by century’s end, but overall people became evolutionists (Artigas et al., 2006).

This change was thanks to Darwin, especially to the structure of the argument in the Origin . The methodologists of science of the day, more

particularly, the methodologists of science of the 1830s when Darwin was discovering and formulating his theory, insisted that the best science has at its heart a true cause, a vera causa . They differed over what is the mark of a vera causa . John F. W. Herschel (1830), with empiricist leanings, insisted that we have direct sensory evidence or something analogical. We know that a force pulls the moon toward the Earth because swinging a stone around on a piece of string requires you to pull the stone in toward you. William Whewell (1837, 1840), with rationalist leanings, insisted that we justify the acceptance of our hypothesis through its implying a whole range of empirical evidence, thus manifesting what Whewell called a “consilience of inductions.” As in a court of law, where the guilt is ascribed through the wide range of clues that it explains, Darwin set about satisfying both vera causa criteria (Ruse, 1975b). First, he argued analogically from artificial selection (the work and triumphs of the animal and plant breeders) to natural selection, from something known and seen to something not known and seen. Then he turned around, and showed how evolution through selection throws light on topics across biology, instinct, paleontology, biogeography, systematics, anatomy, embryology, and more. As evolution through selection explains, so conversely the explained areas justify our faith in evolution through selection.

There are questions about how effective was the appeal to artificial selection. Generally before the Origin it was taken as a reason not to believe in ongoing change (no one has turned a horse into a cow) and I have mentioned how Wallace denied explicitly that it was relevant to the evolution issue. After the Origin , people like Huxley took the failure to create new species artificially as a reason to hesitate before full acceptance of natural selection’s powers. However, undoubtedly at some level the analogy softened people up to evolution. Part of Darwin’s genius was always to put his ideas into comfortable contexts. He argued to natural selection via the struggle for existence, which was something that came out of the thinking of the Reverend Thomas Robert Malthus (1826), who pointed out that population demands will always outstrip potential gains in space and food. Everyone knew about these Malthusian calculations, and, even if they did not much like them, generally they accepted the conclusions. Likewise with the world of breeders, people at least took some comfort from the arguments provided by Darwin, even if they were not definitive.

The consilience was a different matter. Here, Darwin did persuade. At least, he persuaded to a point. As noted, evolution after the Origin was nigh a truism. The mechanism was another matter. No one denied natural selection. Very few accepted that it could be as powerful as Darwin suggested. People became evolutionists in droves. The number of pure Darwinians, as we might term selectionists, was very few, and the most

prominent after Darwin himself, namely Wallace (1870), became enamored of spiritualism in the 1860s and he started to deny selection when it came to humans. The reasons for this halfway acceptance are well known. On one side, there were scientific problems with selection. It was thought that it could never be strong enough to overcome the supposed averaging nature of heredity. Even the best new variations would be swamped into nonbeing in a generation or two (Greg, 1868). Added to this the physicists (ignorant as they were of the warming effects of radioactive decay) denied that there was time enough for such a leisurely process as natural selection (Burchfield, 1975). On the other side, there was the matter of adaptation. Selection does not just bring about change. It brings about adaptive change. This ran into trouble from folk at both ends of the spectrum. German-influenced biologists like Huxley (1884) thought that adaptation is but a minor phenomenon, and hence felt no need to embrace selection on that score. Nonadaptive saltations (jumps, what we today would call “macromutations”) would do the job for evolution. Heavily Christian evolutionists like American botanist Asa Gray (1876) thought that selection could not fully explain adaptation and so they wanted (God-) directed variations. As Darwin said, this rather made natural selection redundant.

So after 1859, it was evolution yes; natural selection, much less so. This meant that the dream that Darwin had had of founding a professional science of evolutionary studies, based on natural selection, never really got off the ground. There certainly was professional evolutionism, particularly that around the German biologist Ernst Haeckel (1866). But, increasingly, a lot of what was produced lost touch with reality as fantabulous tales were spun using the unreliable biogenetic law, ontogeny recapitulates phylogeny. In Britain you had the incredible paradox that the chief post- Origin evolutionist in the second half of the 19th century, a man deeply involved in and highly influential on postsecondary education, Thomas Henry Huxley, never taught evolution to his students. He thought they should concentrate on physiology and morphology (Ruse, 1996).

So evolution became the subject of the popular lecture hall, working men’s clubs, and the public-friendly British Association for the Advancement of Science, and the leading evolutionists moved from the universities to the museums. Huxley student E. Ray Lankester ran the British Museum (Natural History) in London and Huxley student Henry Fairfield Osborn ran the American Museum of Natural History in New York. And what you want in museums are displays, with an educational and cultural message. So this is what was supplied. Terrific displays of fossils, especially of all of those dinosaurs now being discovered and brought back from the American West, and all put in a progressive fashion to demonstrate

that life may have started as blobs but that it ends as humans, especially white humans.

Finally, ≈1930 came the move from popular science to professional science. First there were the mathematicians, the population geneticists mentioned above. Then came the empiricists, the experimenters, and naturalists, who put flesh on the mathematical bones: E. B. Ford and his school in Britain and Theodosius Dobzhansky and his fellow evolutionists in the United States. Now we had university posts, researchers, graduate students and grants, journals, societies, and everything else we associate with professional science, and not just at the sociological level, because the work produced was firmly based on empirical studies with mathematical models doing the explaining. The epistemic virtues of science (consistency, coherence, predictability, fertility, simplicity) were taken seriously and the worth of work was judged by its success against these virtues. And right at the heart was natural selection, which continues to this day. Here, again then Darwin has made a major contribution to evolutionary studies.

WAS THERE A DARWINIAN REVOLUTION? METAPHYSICS

What of the Darwinian revolution in the broader sense, the side dealing with our metaphysical view of ourselves, our place in nature? Here, Darwin was crucially important if not completely successful. He himself was stone-cold certain that we humans are part of the world of nature. His experience with the native people from the bottom of South America, the Tierra del Fuegians, had convinced him of that (Darwin, 1969). And he made his case publicly, as is well known, not in the Origin (which was somewhat reticent on the human question) but in the Descent of Man , published some 12 years later (Darwin, 1871). However, now we must ask what it means to put ourselves in nature. There are 3 possible answers. First, it can simply be to make humans part of the natural order of things. We are ruled by the laws of physics and chemistry and biology and so forth just like anything else. Second, it can be showing that natural selection was the chief causal force making us what we are, and perhaps that selection is still significant. Third, it can be to claim that we are no different from anything else, at least in value or worth. An oak tree, a wart hog, a human, ontologically and axiologically they are the same.

If you are thinking of the first of these claims, if you think of the Darwinian revolution as an attempt to make humans entirely natural, in the sense of produced and working according to the same laws of nature as everyone else, one can truly say that for many people this revolution has succeeded and Darwin played a major role in its success. The Origin put us firmly in the natural picture and then following up the Descent of Man was a major analysis of humankind from a naturalistic perspective, cover-

ing not just our physical frames but also our moral beliefs and social and intellectual natures generally. No one would want to say that it was Darwin alone. Huxley and his Man’s Place in Nature (1863) was a key figure back then and of course there have been literally hundreds of other contributors, in and out of biology, since. But Darwin deserves his name up there. Even those who may not much care for the work actually being produced seem to agree that the naturalistic program is the right one and that it must take evolution into account. Although having said this, it must be admitted that there are many for whom this program is unacceptable, and who would deny that Darwin has succeeded or indeed could succeed. The official Catholic position, for instance, is that we have souls and these are created and inserted miraculously into human frames, actually, human zygotes (John Paul II, 1997). And this obviously is but one end of the spectrum that goes all of the way, through the kind of directed evolution allowed by some members of the intelligent design theorists (Behe, 1996), across to the hard-line young earth creationists who think that humans were created miraculously on the sixth day (Whitcomb and Morris, 1961).

Second, what about natural selection? Again, Darwin is very important, perhaps indeed more important than just the naturalism part. The Descent of Man showed in detail how natural selection (combined with sexual selection) is a crucial explanatory factor behind much that we think of as human, physical, and social. This is a path that many have followed, most notably in recent times by Harvard biologist Edward O. Wilson in his On Human Nature (1978) , a work that covers morality, religion, conflict, and much more. Wilson is not a hard-line evolutionary determinist, but he does argue that (in his language) the twig is bent. The human mind is not a tabula rasa but shaped by the forces of natural selection. And many workers in the evolutionary field today would agree, from physical anthropologists through human behavioral ecologists and on to evolutionary psychologists.

However, 2 reservations must be expressed. First, much that has been claimed in the name of Darwinian selection bears but a passing resemblance to the program of the Descent . Historically, one thinks of social Darwinism, a movement that covered many different ideologies and that generally owed more to Herbert Spencer than to Charles Darwin (Ruse, 2000). When, to take a particularly egregious example, German general Friedrich von Bernhardi (1912) claimed that Darwin showed that might is right and that the Motherland has almost an obligation to seize from its neighbors, he owed little to the old evolutionist who had worked away in his study in the English countryside. One might as much credit Plato because the doctrine more closely resembled the thinking of Thrasymachus in the Republic . Today one has similar divisions. For instance, philosopher Peter Singer (2000) has claimed the authority of Darwin for an explicitly

left-wing manifesto. Philosopher Larry Arnhart (2005) has no less enthusiastically claimed Darwin’s support for a right-wing view of society.

Second, it must be appreciated that (apart from those who reject the naturalistic program in itself) there are those who argue that natural selection is not the appropriate tool to analyze human nature. Clearly a lot of social scientists think this, but so also do prominent biologists. The Harvard geneticist Richard Lewontin, a committed Marxist, is one who denies that evolutionary biology is the key to understanding Homo sapiens . He opts rather for economic and like forces (Levins and Lewontin, 1985). It may well be that the late Stephen Jay Gould shared his sentiments. With some few exceptions, notably Elliott Sober (1981) who has not only argued for the influence of selection on our modes of thinking in the realm of science but who has also coauthored a spirited defense of the selection-based nature of human morality (Sober and Wilson, 1997), the philosophical community feels negatively inclined to the selection-explains-humans program. The particulars are thought wrong; feminist philosopher Lisa Lloyd (2005) launched a heavy attack on the putative biological basis of the human female orgasm. But more importantly the overall program is declared ideological and inadequate. Even those who think there might be a possibility of a selection-based approach to human nature declare regretfully that the quality of the work produced thus far falls far short of the standards of adequate science (Buller, 2005; Richardson, 2007).

We come to the third claim, namely that we humans are not in any way special. You might think that proving this was Darwin’s intent; after all, he did caution himself never to use the terms “higher” and “lower” (writing this on the flyleaf of his copy of Vestiges ) and the mechanism of natural selection is nothing if not egalitarian. What is it better to be, the AIDS virus or a lowland gorilla? Speaking purely biologically, there are few who would speak up for the ape. However, it cannot be gainsaid that if this was indeed the intent of the Darwinian revolution it would have been news to Darwin himself. He always thought of humans as being at the top of the tree of life and European humans as being on the highest branches of all (Richards, 1992; Ruse, 1996). Indeed, in later editions of the Origin he added material suggesting that natural selection leads to progress and ultimately to intelligence. He invoked what today’s evolutionists call “arms races” where lines compete against each other, improving adaptations in the process, and argued that eventually this would lead to intelligence and progress.

If we take as the standard of high organisation, the amount of differentiation and specialization of the several organs in each being when adult (and this will include the advancement of the brain for intellectual purposes), natural selection clearly leads toward this standard: for all

physiologists admit that the specialization of organs, inasmuch as in this state they perform their functions better, is an advantage to each being; and hence the accumulation of variations tending toward specialisation is within the scope of natural selection.

Peckham (1959)

Although most of Darwin’s contemporaries did not rely on selection, they, too, virtually automatically assumed that evolution was progressive, with humans at the top. One possible exception was the older Thomas Henry Huxley who in 1893, 2 years before his death, argued that evolution is not progressive and that if we are to succeed morally we must conquer the evolved beast within (Huxley, 1893). Perhaps even he thought we are special; it is just that we must use our evolved moral senses and intelligence to claim our rightful places at the top.

Where do we stand today? Few actual working scientists are going to make any such claims, especially not in their science. The exceptions, people like the Cambridge paleontologist Simon Conway Morris (2003) who argues that there are niches and that organisms seek them out and occupy them and that at the topic is the intelligence-cultural niche that we humans uniquely have found, tend to keep such speculations for books that are aimed at the general audience. Moreover, there are those, Stephen Jay Gould (1988, 1989) was a leader in this respect, who would say that there is no progress and that the Darwinian revolution shows that there cannot be. Ultimately, natural selection is not a progress-producing mechanism. So we could say that the Darwinian revolution does prove the nonspecial status of humans, and finally today people recognize the fact. However, this may not be the entire truth. A case can be made for saying that still today the popular perception is of progress leading to humans. That was Gould’s lament. Surveys suggest that this is what schoolteachers, even those favorable to evolution, tend to teach to their students (Zimmerman, 1987). And museums as often as not give the same impression. Go to the Museum d’Histoire Naturelle in Paris and find that the display starts with blobs and ends with you yourself on television. If you are in any doubt as to the message, the floor above has a display of technology from the crudest beginnings to the sophisticated forms that we have today.

Summing up: Darwin played a major role in moving us to a naturalistic view of human nature, although there are those (generally if not always working from a religious perspective) who would deny that this can ever be done completely and successfully. Darwin played no less (and perhaps more of) a role in convincing people that natural selection is the key causal factor in molding and perhaps today controlling human nature, although one should be wary of all that is claimed in his name and now there are

many more critics (not necessarily religious) who are uncomfortable with this program and would reject it in part or in whole. One can make an argument that Darwin paved the way for a view of humankind that gives us no special status here on this earth, although this was certainly not Darwin’s own aim and, especially in the public domain, beliefs privileging humans persist today.

WAS THERE A DARWINIAN REVOLUTION ?

Finally, how does one analyze conceptually what happened because of the Origin of Species ? Let us start with 2 basic theories of theory change. On one hand, we have the fairly traditional view, represented by the logical empiricists like Ernest Nagel (1961) and Carl Hempel (1966). This view tends to stress continuity, with moves made driven by the evidence and reason. To a certain extent, there will be replacement of old theories by newer, truer theories. Something like this happened when Copernicus knocked out Ptolemy. But there will probably be continuity. There was in the Copernican case. It was the same world that the two were describing: the same earth, the same sun, the same moon, the same planets, the same stars. Both sides agreed that circular motion must be preserved. Both sides used epicycles and deferents. It is true that almost all of this was changed as the years went on, but the growth of science was evolutionary not revolutionary. You can have revolutions, but they are gradual, not abrupt, and important is the notion of reduction, when one theory is absorbed in another, or more accurately when one theory can be shown the special consequence of another theory. Supposedly the macroscopic understanding of gases (Boyle’s law and so forth) could be shown a special instance of the kinetic theory of gases.

On the other hand, we have the revolutionary view of Thomas Kuhn (1962). Here, the change is abrupt. In Kuhn’s terminology we go from one paradigm to another, and there is no continuity. Hence, the change of viewpoint, from one paradigm to another, can never be fueled by reason. It always has to be more of a conversion experience. This is the reason there is often such bitter fighting between scientists. There is no common or shared set of beliefs that can be decisive. As with political disputes, everyone argues from within their own system.

Without wanting to homogenize everything into a gray blandness, it is probable that both positions have things to say that throw light on Darwin and his achievements. Clearly, as the logical empiricists would lead one to expect, in some respects Darwin was replacing old positions with new ones. If you think for instance of Darwin’s old friend and mentor, the violently antievolutionist, Cambridge paleontologist Adam Sedgwick (1850), Darwin is simply saying that Sedgwick’s reading of the

fossil record is wrong. Sedgwick argues that there are and always will be gaps in the record and that these represent real breaks in the continuity. Darwin is saying that the gaps are artifacts of incomplete fossilization and that there were bridging organisms, even if we never find them, although that should never stop us in the pursuit of such links. An analogous argument holds for the problem of the pre-Cambrian period. At the time of the Origin , there were no organisms at all from this period and their absence was rightly taken as a major problem for Darwin’s theory. The earliest organisms of all, like trilobites, were highly complex and sophisticated invertebrates. How could they have just arrived on the scene? Sedgwick said simply that there were no pre-Cambrian organisms. Darwin said that they had existed. Two conflicting views and as Darwin’s overall theory was accepted, Sedgwick was pushed out. Today we have many such organisms, and we know that Darwin was right (Knoll, 2003). We had a simple case of one theory being right and the other wrong, and the right one pushing out the wrong one.

What about reduction? One does not see any cases of whole positions being taken up by Darwin’s theory, but if you look at the range of other pre- Origin positions, talk of reduction does not seem entirely inappropriate. Think of the position of someone like Richard Owen, deeply influenced by the Naturphilosophen . In a work like On the Nature of Limbs (Owen, 1849), it is hard to say if he is actually endorsing evolution; the answer is that he probably was but that he wanted to be sufficiently ambiguous to escape the critics. (Even as it was, Sedgwick was highly suspicious.) More importantly, although Owen certainly does not deny adaptation, he stresses homology in a very big way. Now when Darwin comes along with the Origin , he is certainly not going to stress homology over all other things as did Owen, but he is not going to deny it either. Most interestingly, he argues that it follows as a consequence of evolution through natural selection.

It is generally acknowledged that all organic beings have been formed on two great laws: unity of type and the conditions of existence. By unity of type is meant that fundamental agreement in structure, which we see in organic beings of the same class and which is quite independent of their habits of life. On my theory, unity of type is explained by unity of descent. The expression of conditions of existence, so often insisted on by the illustrious Cuvier, is fully embraced by the principle of natural selection. For natural selection acts by either now adapting the varying parts of each being to its organic and inorganic conditions of life; or by having adapted them during long-past periods of time: the adaptations being aided in some cases by use and disuse, being slightly affected by the direct action of the external conditions of life, and being in all cases subjected to the several laws of growth. Hence, in fact, the law of

the conditions of existence is the higher law; as it includes, through the inheritance of former adaptations, that of unity of type.

Darwin (1859)

This is what theory reduction is all about. Darwin would not have accepted every aspect of Owen’s thinking. But there was continuity, with older ideas being absorbed into newer ones, and this is an important thing to note about Darwin and his work and his importance.

Now let us express some sympathy for the Kuhnian view. Take the question of homology and pick up on the point where Darwin and his supporters would break with Owen. Huxley (1857–1859) brings out this opposition in his Croonian lecture on the vertebrate skull, given at the Royal Society the year before the Origin appeared. He faulted Owen for being an idealist rather than a naturalist, claiming (correctly) that for Owen the archetype represents a divine platonic pattern rather than something produced purely by mechanical laws. As it happens, he also claimed correctly that this led Owen to see more than was justified, namely that the skull is made from transformed vertebrae, a claim that Darwin had accepted and that he dropped smartly before the Origin appeared. The point is that, evolutionist or not, Owen did have a vision of the world that was fundamentally different from that of Darwin. And it persisted after the Origin , as he tied himself in knots over the hippocampus, present or not in humans and apes (Rupke, 1994). It was not the facts as such that counted, but different visions of reality.

So in this sense, we do have something Kuhnian going on, different paradigms if you will. But note that it is not just a question of evolution or not evolution, and certainly not of selection or not selection. Nor is it simply a matter of biblical literalism. There were literalists, increasingly in the American South, but by and large this is not an issue in the debate around the Origin . Literalism had more to do with a defense of slavery than with the interpretation of fossils (Noll, 2002; Ruse, 2005). The big religious critics like Sedgwick and Bishop Wilberforce all accepted an old earth and a lot more. It is rather “man’s place in nature” that was at stake. Owen was on one side. So was Sedgwick. Darwin’s great American supporter Asa Gray was on this side, too, a point that Darwin saw, when he grumbled that Gray’s appeal to directed variations took the discussion out of the realm of science. And we could include more, especially Darwin’s old friend, the geologist Charles Lyell, who staggered across the evolutionary line but bitterly regretted having “to go the whole orang” (Wilson, 1970). On the other side, we have Darwin and Huxley (for all that the latter downplayed the significance of selection). And also there was Joseph Hooker, the botanist, and increasingly a host of younger workers

who did not depend on church appointments for their incomes and who wanted to work and think in a secular fashion.

And in confirmation of Kuhn, this is where we tend to get the nastiness: Sedgwick (1860a,b) writing irate letters to the newspaper about Darwin’s methodology; Bishop Wilberforce (Huxley, 1900) sneering at Huxley’s ancestry; Owen (1860) doing everything he could to give the Darwinians a bad name; and so forth. There were certainly vigorous debates about the science, but rarely did the science itself cause unpleasantness. It was always (as in the Huxley-Owen squabble over the brain) in the cause of the bigger metaphysical picture. Very instructive is the age-of-the-earth question. Physicist William Thompson (later Lord Kelvin) did not much like Darwin’s naturalistic approach to humankind, but he objected publicly to the long time span that Darwin needed. As it happens, Thompson’s research assistant was none other than George Darwin, Charles Darwin’s mathematically gifted son. So Charles Darwin was not allowed to forget or escape the problem. However, even though in the end they simply had to disagree, neither Charles Darwin nor Kelvin thought that the disagreement was personal or ideological. It was just not that sort of difference (Burchfield, 1974). So in the sense that there were differences of that sort, differences where because of rival metaphysical views people talked past each other, one could claim that the Darwinian revolution was Kuhnian.

There is another way in which Kuhn’s thinking is insightful. A paradigm is a world picture, within which a scientist works, that gives him or her tasks for the future, and which seems obvious or certain in some sense. Obvious or certain in the sense that (as just noted) you cannot see the point of view of others not in the paradigm (Ruse, 1999). Think again of the divide in biology between formalism and functionalism and put it in a broader historical context. As Aristotle pointed out, on one hand we have the adaptive side to organisms, what he called final causes, meaning that the parts function for the benefit of the whole. On the other hand, we have homologies (isomorphisms) where the parts may well be used for different ends. Down through the ages people have continued to note these 2 sides to organisms, and interestingly people tend not to be ecumenical on the matter. Like Darwin, they are partisans for one side or the other. Either they opt for function with form secondary or form with function secondary. What is fascinating is the way that this divide goes right across the Darwinian revolution. At the beginning of the 19th century one had formalists who did not accept evolution, many of the Naturphilosophen for instance. The philosopher Hegel (1817) is a case in point. One also had functionalists who did not accept evolution. The great French comparative anatomist Georges Cuvier (1817), with his theory about the conditions of

existence (that he explicitly tied to final-cause thinking), was one such person. Then at the time of the Origin we have people who crossed the evolutionary divide who were one or the other, but not both. Darwin was a hard-line functionalist. That is the whole point of natural selection. Huxley equally was a hard-line formalist (Huxley and Martin, 1875). That’s why he could not see much need of natural selection. Today, the differences persist. Take the 2 great popularizers of evolution, Englishman Richard Dawkins and American Stephen Jay Gould. Dawkins (1976, 1986) is and always has been an ardent functionalist. For him, it is adaptation all of the way and the only problem really worth solving. He thinks natural selection is a universal law of nature. Gould (1977b, 1989, 2002) was notoriously ambivalent about natural selection and function, thinking it a holdover from English natural theology, and he again and again stressed form. This was the central message of his famous paper on spandrels, cowritten with geneticist Richard Lewontin (Gould and Lewontin, 1979).

I would argue that in a real sense we have Kuhnian paradigm differences operating here. Different visions, unable to bridge the gap (Ruse, 2003). I find it interesting that metaphors are involved, things that Kuhn stresses as being important in paradigm thinking. We have the organic world as a human artifact. [See Darwin’s use of this metaphor in the little post- Origin book on orchids (Darwin, 1862).] We also have the organic world as a snowflake [Kant’s 1790 picture (Kant, 1951)] or as a crystal [used by Whewell (2001)]. Admittedly, this sense of paradigm does not fit exactly with the senses of paradigm found in the Structure of Scientific Revolutions . For a start, both sides do recognize some of the merits of the other side. It is hard to think that the ontologies are completely different. For a second, with respect to the same things 2 people could be in and out of different paradigms. With respect to homology, Owen and Huxley were divided over the idealistic/naturalistic issues, and yet with respect to thinking that homology more important than function, they were together. Third, perhaps most importantly, the 2 paradigms (without prejudice, let us call them this) persist, down through the ages. It is not a matter of one beating out the other. It is true that today functionalism has the upper hand, but things could change. In fact, in the past 20 years things have moved, with evolutionary development enthusiasts coming onside in a very strong way for formalism. The homologies they find, for instance between humans’ and fruitflies’ genetic sequences, strike them as absolutely fundamental and calling for a total revision of evolutionary thinking.

The homologies of process within morphogenetic fields provide some of the best evidence for evolution, just as skeletal and organ homologies did earlier. Thus, the evidence for evolution is better than ever. The

role of natural selection in evolution, however, is seen to play less an important role. It is merely a filter for unsuccessful morphologies generated by development. Population genetics is destined to change if it is not to become as irrelevant to evolution as Newtonian mechanics is to contemporary physics.

Gilbert et al. (1996)

We shall have to see how this all pans out. An ardent Darwinian like me is less than overwhelmed (Ruse, 2006, 2008). But then I am an ardent functionalist, so I am proof of the point I am making about the divide. Obviously, the ideas do persist and not just as fossils.

If the point being made now is well taken, then perhaps Hodge was right all along. There was no Darwinian revolution. The paradigms of form and function went in before Darwin and came out after Darwin. This taken as a general conclusion is obviously false. Because of Darwin and the Origin of Species , major things did happen in biological science. Less paradoxically, let us say that a complex phenomenon like the Darwinian revolution demands many levels of understanding. Blunt instruments will fail us as we try to understand scientific change. It is necessary to tease strands apart and consider them individually as we try to understand and to assess what is going on.

There are other controversies (unmentioned thus far here) very active today. Often these involve not just the events directly around Darwin but aspects of the broader picture. Robert J. Richards (who has been noted as a major contributor to the history of evolutionary biology) argues that the post-Darwinian period, especially that influenced by the German evolutionist Ernst Haeckel, was much more pure-Darwinian than people have recognized. He thinks that Darwin was deeply Romantic in his thinking, influenced by the currents that came from Germany at the beginning of the 19th century, and that after the Origin people like Haeckel were simply responding to and building on that which was already there (Bowler, 1976; Richards, 2002). Other students of the period (including myself) disagree strongly, thinking that (as Karl Marx noted) Darwin was quintessentially English in his thinking and that it is right to see Haeckel as responding to non-Darwinian themes, an attitude that inflected evolutionary biology until the synthesis of the 1930s (Ruse, 2004). Another controversy centers on the work and interpretations of Peter J. Bowler (also noted above as a major contributor). He agrees that post-Darwinian thought was deeply non-Darwinian, but he nevertheless thinks that it was good-quality science and that it fed smoothly into the synthesis. Indeed the latter would not have occurred without the former (Bowler, 1988, 1996). Others, again

including me, disagree strongly, arguing that post-Darwinian evolutionary biology was often really poor-quality science (notoriously following Haeckel in spinning unsustainable analogies between embryology, ontogeny, and paleontology, phylogeny) and that the synthesizers of the 1930s had to cleanse the Augean stables and return to the thinking of the Origin (melded admittedly with the new genetics) before further advance was possible (Ruse, 1996).

These controversies, however, must be the topic of another essay. Here, I rest confident that I have shown why, for a philosopher and historian of science, analyzing the Darwinian revolution is such a worthwhile challenge.

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Two Centuries of Darwin is the outgrowth of an Arthur M. Sackler Colloquium, sponsored by the National Academy of Sciences on January 16-17, 2009. In the chapters of this book, leading evolutionary biologists and science historians reflect on and commemorate the Darwinian Revolution. They canvass modern research approaches and current scientific thought on each of the three main categories of selection (natural, artificial, and sexual) that Darwin addressed during his career. Although Darwin's legacy is associated primarily with the illumination of natural selection in The Origin, he also contemplated and wrote extensively about what we now term artificial selection and sexual selection. In a concluding section of this book, several science historians comment on Darwin's seminal contributions.

Two Centuries of Darwin is the third book of the In the Light of Evolution series. Each installment in the series explores evolutionary perspectives on a particular biological topic that is scientifically intriguing but also has special relevance to contemporary societal issues or challenges. The ILE series aims to interpret phenomena in various areas of biology through the lens of evolution and address some of the most intellectually engaging, as well as pragmatically important societal issues of our times.

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