Peter Lipton was Hans Rausing Professor and Head of the Department of the History and Philosophy of Science at the University of Cambridge and a Fellow of King's College. He was also a member of the Nuffield Council on Bioethics and chaired its working party on pharmacogenetics. He was an undergraduate at Wesleyan University and a graduate student at Oxford University; before coming to Cambridge, he taught at Clark University and Williams College. His philosophical interests included the structures of explanation and inference in science, the nature of scientific progress, social epistemology, and various topics in biomedical ethics. He was the author of Inference to the Best Explanation (second edition, 2004) and was the 2004 Medawar Prize Lecturer of the Royal Society. He died unexpectedly in November 2007.