In this important new collection, six internationally famous contributors--Bernard Williams, Derek Parfit, Henry Harris, Michael Ruse, Terence Cave, and Anthony D. Smith--discuss identity from the viewpoints of their various disciplines. Identity is a matter of personal and practical as well as intellectual interest, and perhaps for this reason academic debate on this subject attracts attention and stimulates controversy outside the ranks of the specialists. This volume offers a comparison and cross-fertilization of insights and theories from outside and within philosophy, shedding light on this concept crucial to the humanities and the social and physical sciences.