Personal Identity brings together the most important readings on personal identity theory in a collection ideal for students, philosophers, and all other interested readers. The volume begins with a detailed introductory historical essay by the editors, which traces the evolution of personal identity theory in the West from classical Greece to the twentieth century. It also describes how, in the early 1970s, philosophers shifted their attention from the ‘internal relations’ view of personal identity to an ‘external relations’ view that explores, among other considerations, what matters in survival.The essays that follow are delineated by this twentieth-century philosophical shift. The first section features seminal papers by such luminaries as Bernard Williams, Derek Parfit, Robert Nozick, and David Lewis. These are the very scholars that were involved in initiating the revolution in personal identity theory. The second section features papers by Christine Korsgaard, Peter Unger, Ernest Sosa, Raymond Martin, Marya Schechtman, Mark Johnston, and Derek Parfit that focus primarily on the new question of survival. Finally, a recent paper on animalism by Eric Olson and one on the self by Galen Strawson indicate new directions in which further discussion might continue.