Scientific racism was at the centre of Aryanism, but it was quite possible to be a scientific racist without specific commitment to the Aryan myth – the middle-class progressive subscribing to eugenics as the race science of the future was once an entirely familiar phenomenon. As late as 1936 Julian Huxley, by no means a reactionary, was arguing that ‘once the full implications of evolutionary biology are grasped, eugenics will inevitably become part of the religion of the future, or whatever complex of sentiments may in the future take the place of organised religion’. This seeming paradox was due to an extraordinary cultural convergence at the turn of the nineteenth century. Once reliant on an increasingly discredited appropriation of linguistics and the deployment of highly romantic historiographies, by the end of the century the science of race had become hugely reinforced and greatly sophisticated. Now liberals, progressives and conservatives alike were subject to what were perceived to be the hard facts and inexorable logic of Lamarckian and Darwinian biological science.

And yet, as Peter Bowler, an eminent historian of evolution, has argued, there was no necessary connection between Darwinism and progressivism. Indeed, divergent evolution alone should have led Darwin and Darwinists to reject progressivist teleology. But Darwin wrote for a public ‘already conditioned to think of evolution as the unfolding of a purposeful trend towards a morally significant good’.