What does it mean to be a person? The philosophical problem of personal identity has been the subject of much debate in both Western philosophy and Buddhist philosophy. This book initiates a conversation between the two traditions showing how concepts and tools drawn from one philosophical tradition can help solve problems arising in another, particularly as regards the philosophical investigation of persons. The recent controversy over personal identity has concerned reductionism, the view that persons are mere useful fictions. Mark Siderits explores the most important objections that have been raised to reductionism, and shows how some key arguments and semantic tools from early Buddhism can be used to answer those objections. Buddhist resources are used to examine the important ethical consequences of this view of persons. The second half of the book explores a new objection to reductionism about persons that originates in Mahayana Buddhist philosophy.