Book excerpt: The naturalist and geologist Charles Darwin (1809–82) ranks as one of the most influential scientific thinkers of all time. In the nineteenth century his ideas about the history and diversity of life - including the evolutionary origin of humankind - contributed to major changes in the sciences, philosophy, social thought and religious belief. The Cambridge Companion to Darwin has established itself as an indispensable resource for anyone teaching or researching Darwin's theories and their historical and philosophical interpretations. Its distinguished team of contributors examines Darwin's main scientific ideas and their development; Darwin's science in the context of its times; the influence of Darwinian thought in recent philosophical, social and religious debate; and the importance of Darwinian thought for the future of naturalist philosophy. For this second edition, coverage has been expanded to include two new chapters: on Darwin, Hume and human nature, and on Darwin's theories in the intellectual long run, from the pre-Socratics to the present.