Annals of the History and Philosophy of Biology

182
Annals of the History and Philosophy of Biology, Vol. 10 (2005)
Michael Ruse
observer. But however you read Kuhn, he does argue that people see the facts differently
– it is not just a question of interpretation, but of the facts themselves. This is simply not
true of the Darwinian Revolution. Everything I have said above about Darwin himself
denies this claim.
Darwin was not the Christian God, making things from nothing. He was much more
like Plato’s Demiurge, shaping what he already had. This applied to ideas as well as facts.
Everyone knew about Malthus, for instance, but it was Darwin’s genius to put the ideas
into a theory of change rather than a theory that argued that change is impossible. Likewise,
the facts of the successes of animal and plant breeders were well known. It was
again Darwin’s genius to make something of these facts. The same is true of so much
else – the vaguely progressive fossil record, for instance, and the peculiarities of biogeography.
Particularly important for Darwin were Ernst von Baer’s discoveries in embryology.
Darwin seized on the similarities of embryos and made this a key support for the
arguments of the Origin.
Let me underline this point by drawing attention to the time after Darwin and returning
briefly to the students of Agassiz. It was notorious then – and it is a burden of historians
of science now – that it is often absolutely impossible from reading their papers to
tell if they have crossed the evolutionary divide or not. Alpheus Hyatt (1889) was a firstclass
invertebrate paleontologist, yet a foggy writer by anyone’s standards – his papers
drove Darwin to despair – and part of that fogginess is that one simply does not know
where he stands on the issue of evolution. I do not know how else you can describe this
phenomenon except by saying that the facts remained the same and the interpretation
mattered.
Although having said this, I think in respects we should switch back to something a
bit Kuhnian. If you take natural selection out of the picture – and most people at that
time did – then it seems to me that the switch to evolution was in a way more of a metaphysical
switch, a switch to a natural world, than simply one of science. Imagine if you
read a molecular biology paper of the late 1950s, and you could not tell if the author
accepted the double helix! It would be impossible.
So I do not want to say that the facts in the Darwinian Revolution were unimportant.
People were very impressed by the information in the Origin. But I do want to say that
there was more than just a rational-choice-powered switch. I would also be inclined to
say something similar in the case of natural selection. There is no doubt that Ronald
Fisher was a fanatically committed Englishman, and the heritage and glory of Charles
Darwin was part and parcel of this. (Fisher was a friend of and fellow eugenicist with
Darwin’s youngest surviving son, Major Leonard Darwin. Indeed, the rich, childless
Darwin helped out the always-underfunded, large Fisher family.) I would entertain sympathetically
an argument that said that, for Fisher, natural selection was more than just
something justified by the facts and also something with deep cultural significance and
hence to be cherished.
But let us not get too carried away by this line of argument. Take Theodosius Dobzhansky.
Although initially, in the first edition of his Genetics and the Origin of Species (1937),
he does not give an overwhelming role to natural selection, by 1941 when he published
the second edition he was moving to selection. This was certainly not fueled by a love of