For nearly one-and-a-half centuries, biologists interested in evolution have been haunted by the question of whether their conceptions are or are not 'Darwinian'. While it may not be unique, this persistent positioning of new developments in relation to a single, pioneering figure is quite exceptional in the history of modern natural science. Physicists currently working in the domains of relativity or quantum theory may refer sometimes to Einstein or Bohr; but their debates are not massively structured by this reference as evolutionary theory has been and remains structured by reference to Darwin. A proximate cause of Darwin's enduring presence is that evolutionary biologists have never stopped reading him. The remarkably numerous editions and translations of Darwin's books have in themselves helped to make this possible. But the availability of key texts only takes us so far in understanding why evolutionary biologists go on reading Darwin, referring to him, feeling the necessity of labelling their theories as 'Darwinian' or 'non-Darwinian' or 'anti-Darwinian'. Indeed, on the face of it, there are compelling reasons for modern biologists to avoid affiliating their work with Darwin's. Darwinism does not belong only to the history of science; it also belongs to cultural and political history. Among other things, neo-liberal economics, social Darwinism, racial anthropology, Nazi ideology and the materialistic monism of Darwin's German supporter Ernst Haeckel had strong interactions with Darwinism in the first century of its history.