Daniel J. Nicholson is a research fellow currently based at Egenis, The Centre for the Study of Life Sciences, at the University of Exeter. Previously, he held appointments at the Cohn Institute for the History and Philosophy of Science and Ideas in Tel Aviv, as well as at the Konrard Lorenz Institute for Evolution and Cognition Research near Vienna. His work is characterized by an integrated and strongly interdisciplinary approach to the history and philosophy of biology, with a specific interest in the ontology of living systems and the adequacy of mechanistic explanations to make sense of them. He is also interested in general topics in the philosophy of science and in theoretical biology, broadly construed. John Dupre is Professor of Philosophy and Director of Egenis, The Centre for the Study of Life Sciences, at the University of Exeter. He has formerly held posts at Oxford, Birkbeck College, London, and Stanford, and visiting chairs at the University of Amsterdam and Cambridge. He has wide-ranging interests in the philosophy of biology, the philosophy of science generally, and naturalistic, empirically grounded metaphysics. He is a former president of the British Society for Philosophy of Science, and a Fellow of the American Association for the Advancement of Science.