This book investigates the specific conception and descent of a language of ‘degeneration’ from 1848–1918, with particular reference to France, Italy and England. Daniel Pick shows how in the refraction and wake of evolution and naturalism, new images and theories of atavism, ‘degenerescence’ and socio-biological decline emerged in European culture and politics. He indicates the wide cultural and political importance of the idea of degeneration, whilst showing that the notion could mean different things at different times in different places.