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Samuel Grove

Samuel Grove recently published Retrieving Darwin’s Revolutionary Idea: The Reluctant Radical. In commemoration of the 150th Anniversary of The Descent of Man (1871), Roberto Navarrete sat down with him to discuss the philosophical dilemmas Darwin faced in applying his theory of natural selection to human beings.

Darwin isn’t generally known as a philosopher. Didn’t he explicitly avoid grand philosophical speculation in favour of science?

Indeed. But that doesn’t mean to say he wasn’t interested in philosophical questions. He just believed that they were best approached from a scientific angle: “He who understands baboons would do more toward metaphysics than Locke” he wrote in his notebook. Elsewhere he wrote:

“To study Metaphysics, as they have always been studied appears to me to be like puzzling at astronomy without mechanics. – Experience shows the problem of the mind cannot be solved by attacking the citadel itself. – the mind is function of body. – we must bring some stable foundation to argue from.”

Darwin was fascinated by the problem of free will, for example. Like the philosophers, he was plagued by how freedom could arise in a universe that from a scientific perspective appeared to run on mechanical cause-and-effect lines, in a predetermined fashion. Darwin’s solution was primarily one of method. If your point of entry is philosophical you will quickly become entrenched in an irresolvable paradox; but if your point of entry is scientific – that is, if you cut the problem down to size and focus on more manageable problems – you might get somewhere. “Our faculties are more fitted to recognize the wonderful structure of a beetle than a Universe,” he wrote.

What does this mean in practical terms? In the case of free will, Darwin’s hunch was that it was intimately related to the variation in nature. Ascertain the origin of variation and its accompanying laws, and you will make more progress concerning free will than philosophers have made in hundreds of years. Indeed, Darwin spent much of the years between The Origin of Species and The Descent of Man studying plants and animals under domestication. His concern was clearly scientific: he wanted to secure the foundations for his theory of natural selection. But, as he revealed in the final paragraph of his laborious two volume study, The Variation of Animals and Plants Under Domestication (1868), he also hoped he’d shed light on the origin of free will.

Darwin published The Origin of Species in 1859. It took a further twelve years for him to publish the application of his theory of natural selection to human beings in The Descent of Man in 1871. What took him so long?

Well, there’s a long and a short answer to this question. The short answer is that he didn’t want to write the book. Darwin closed The Origin of Species with the famous phrase ‘light will be thrown on the origin of man and his history’, and hoped his scientific peers would draw the necessary conclusions, perhaps even take responsibility for writing the book themselves. They didn’t. Even his closest allies weren’t prepared to do so. Charles Lyell, Thomas Henry Huxley, even Alfred Russel Wallace stopped short of applying natural selection to humans. Darwin realised that he couldn’t avoid the issue. He had to make the argument.

Why didn’t he want to write it?

Sam Grove

The most common explanations for Darwin’s reluctance are political and scientific. Political because Darwin did not want to court the controversy that Robert Chambers for example had had after firing off a pro-evolutionary broadside years earlier. Recall that Darwin had already sat on his theory of natural selection for a couple of decades before Alfred Russel Wallace wrote to him with a near identical theory in the late 1850s, which forced Darwin’s hand. Darwin was undoubtedly worried about how his theory of evolution by natural selection would be received, and he was no less worried about spelling out the consequences of this theory for humans. Darwin’s political hesitancy contributed to his scientific caution. Darwin scholars point out that he did not like to present an argument, least of all a radical and unpopular one, until he had assembled all the necessary evidence and anticipated and resolved to his satisfaction all the criticisms that could be levelled against it.

Do you find these explanations for Darwin’s reluctance satisfactory?

I think they contributed to his hesitancy, and ultimately the way he formulated the argument. But I think focusing purely on the political and scientific challenges Darwin faced possibly underestimates the bind he believed he was in. After all, Darwin’s political conservatism did not stop him publishing The Origin of Species, which already laid out his radical argument for common origin of all living things. This is not the actions of someone paralysed by political timidity. Nor was Darwin put off by the magnitude of the problem of human evolution. As early as the 1830s, Darwin’s notes reveal that he was engrossed in the consequences of evolution for human history. Darwin never shirked hard scientific problems. However, Darwin also faced a couple of philosophical paradoxes in applying natural selection to man. Once we know what those philosophical paradoxes were, we get a much better sense of just how politically incendiary, and how scientifically perilous, his task was.

What were the philosophical paradoxes?

As much as Darwin scholars wish to distance him from the continental philosophers, his concerns were very traditional. Since Immanuel Kant (1724-1804), philosophy had been concerned with how natural history – which was a history of errors, faults, failures and fallacies – could give rise to a person capable of self-knowledge and truth. Well, this was also a problem that concerned Darwin. For instance, how could evolution, which had produced an infinite variety of living organisms with no conception of their history at all, give rise to a solitary species that at a particular moment in time has a conception of its history? This wasn’t something that could simply be explained away through happenstance or contingency. And everything about the theory of natural selection seemed to militate against it being possible. Take the example of laws. Natural selection is premised on three laws: the law of inheritance, the law of variation, and the law of superfecundity (where organisms produce more offspring than can possibly survive). Together, these laws produce selection, and over the course of time, evolution. Well, Darwin’s question was, how could evolution produce a subject capable of knowing these very laws? Or, why would evolution select for fidelity to truth or laws? Selection favours survival, not truth. Surely evolution would favour those who were prepared to lie and cheat in the service of their own survival, rather than an organism dogmatically committed to laws and truth?

What was Darwin’s answer?

Darwin’s answer, I believe, reveals just how rattled he was by the problem. In The Origin, he had been adamant that selection only ever takes place at the level of the individual organism. He went to laborious lengths to prove this was the case. As his pre-Origin manuscript, the Big Species Book, revealed, Darwin was willing to stretch metaphors to breaking point on this issue. He was not prepared to give ground on individual selection. However, by the time of The Descent of Man he was suddenly prepared to make an exception: fidelity to truth couldn’t confer an advantage to individuals, but it could, theoretically, confer an advantage to groups. Thus he argued that humans evolved the capacity to think lawfully through a selection for courage that favoured some ‘tribes’ over others. This was the one and only time in his published writings that he allowed for the possibility of group selection; and he wouldn’t have resorted to a group selection argument unless he thought it absolutely necessary.

Had he dealt with the paradox satisfactorily?

No – but not because he resorted to group selection. Darwin’s commitment to individual selection was always a misjudgement in my opinion. Rather I think his argument stands out for being uncharacteristically facile and simplistic. If you read Darwin’s other writings, he is extremely cautious about committing to any selection process. Indeed, in The Origin he stops short of committing to any historical process of selection at all, sticking instead to hypothetical examples where selection could have taken place on the condition of certain premises.

So why in The Descent of Man did he include this evolutionary story about tribes?

A charitable reading would grant that Darwin isn’t trying to provide a definitive answer, but merely proposing another hypothetical scenario to show that the evolution of truth was not quite the paradox it appeared to be. A less charitable reading – and the one I probably favour – is that the example allowed him to present human evolution in a very palatable, aggrandizing way that, he hoped, would pacify probable controversy and outrage.

So he included it because it was politically expedient?

Yes. So his argument was that at the level of groups there had been a slow, steady selection for courage and for loyalty to truth, culminating in Anglo-Saxon man. Darwin was very explicit about this in The Descent of Man. Anglo-Saxon men were the most courageous and the most honest group of human beings, and it was because of their honesty and courage that they had come to dominate the world. I suspect that Darwin probably did believe this. After all, this was the common garden variety racism of the time. However, it certainly didn’t hurt that he was lavishing such praise on precisely the type of people he needed to convince.

Note also that this was pretty much the only time that Anglo-Saxon men are mentioned in The Descent of Man. For the rest of the book Darwin observes animal origins in human subjects lower down the pecking order – indigenous ‘savages’, slaves, women, the poor, the Irish, and so on. There is a very conscious attempt in The Descent to insulate people like himself – subjects who are supposed to be purveyors of truth – from the implications of evolution.

Was this flattery characteristic of his writing?

Not at all. In The Origin Darwin had gone to great lengths to humble man’s sense of exception. Recall that Darwin began The Origin with an analogy for artificial selection, that is, the human selective breeding of animals. He then makes a great deal of the fact that man’s powers of selection in breeding are infinitesimal in comparison to nature’s power of selection. Darwin’s deprecation of ‘feeble man’ is a recurring theme throughout the book. It also, in my opinion, inspires Darwin’s most imaginative prose, when he channels Hamlet’s speech ‘What a piece of work is man’ to say:

“how fleeting are his wishes and efforts! how short his time! and consequently how poor will his products be, compared with those accumulated by nature during whole geological periods. Can we wonder, then, that nature’s productions should be far ‘truer’ in character than man’s productions; that they should be infinitely better adapted to the most complex conditions of life, and should plainly bear the stamp of far higher workmanship?” (Origin, p.84)

Why does he say this when artificial selection is dealt with only in the first chapter? Well, of course, Darwin isn’t just talking here about artificial breeding. He is making the much more general point that the scale of natural selection is incomprehensible to us. It happens with a degree of complexity and over a length of time that is ‘inconceivable’ to us (p.282). Darwin really couldn’t have been any more emphatic on this point. He makes reference to man’s profound ignorance of evolutionary history dozens of times in The Origin.

Charles Darwin
Charles Darwin by Woodrow Cowher

Why was he so insistent on that point?

For very good reason. Despite his reluctance to address human evolution directly in The Origin, he was otherwise very serious about applying evolution’s consequences. One of the principles of the theory was that organisms are entirely unconscious of the selective processes going on around them. This is obviously the case with something as primitive as bacteria, but for Darwin it also had to be true of more complex animals as well. And if you think about it, he’s right. If we grant that all the characteristics of an organism, including their behaviour, is either the result of genetic inheritance or genetic variation, what room is there for conscious consideration? Whatever appears to be conscious decision-making in the organism’s natural struggle for survival is an illusion. Rather, natural selection is simply a combination of instinct (through the law of inheritance) and blind chance (law of variation). In his theory at least, there’s no scope for an organism to become consciously aware of the selective forces surrounding them. This is why Darwin is so adamant in The Origin, and indeed all through his writings, that selection is unconscious.

But humans do have the power to reason.

Exactly. This is the paradox. Darwin’s solution, as with the problem of free will, was to cut the problem down to size. Instead of focusing on reason in its highest form – that of humans – Darwin conjectured that vestiges of it must be found in animals much lower down the scale of nature. His final work, on worms, addresses this question. From analysing worms in their burrows, Darwin surmised that their behaviour could not be reduced simply to instinct and blind chance – that, in fact, worms had evolved the capacity to make primitive judgements. This perspective was also a feature of his early works. In The Origin he wrote “A little dose of judgment or reason often comes into play, even in animals very low in the scale of nature” (p.208). Of course, just because worms are able to use judgement in constructing and furnishing their burrows does not mean they have the capacity to reason on anything as complex as their own evolution! Well in fact Darwin saw humans the same way. He was willing to grant that human beings had evolved the capacity to reason on historical causes and effects, and in isolated cases make reasonable speculations on how this or that organism evolved, but we are never in a position to definitively say how something evolved. And, in the case of our own evolution, we are no closer to understanding that than any other organism understands theirs. As he wrote in a letter, “A dog may as well speculate on the mind of Newton.”

Fine. But this does seem like Darwin is surrendering to the problem on empirical grounds: on the grounds that the problem is empirically too difficult.

No doubt Darwin did consider the problem of the origin of reason too difficult. But it is clear that Darwin considered it axiomatic that humans could never become fully conscious of the selective forces surrounding them. If we did, it would no longer be an unconscious process of selection, and so ‘natural’ selection would no longer apply to us. It might even give rise to a different evolutionary process – one of consciously directed evolution. This would, in effect, endow humans with the power of a deity – the power to be a cause of itself. Yet if there was one principle Darwin was never prepared to concede, it was that man is granted a special exemption from natural selection. As he put it in his notebooks, “Man is not deity, his end under present form will come.” So ironically, the very fact that natural selection does apply to us means we can’t apply it to us, or it would cease to be natural. This is the paradox. This was the essence of Darwin’s dilemma. So Darwin’s reluctance to write The Descent of Man was, in fact, quite justified.

Roberto Navarrete obtained his PhD in neuroscience at University College London, and then was a senior lecturer at Imperial College London.

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