Physicalism, a topic that has been central to modern philosophy of mind and metaphysics, is the philosophical view that everything in the space-time world is ultimately physical. The physicalist will claim that all facts about the mind and the mental are physical facts and deny the existence of mental events and state insofar as these are thought of as independent of physical things, events and states. This collection of essays offers a series of perspectives on this important doctrine and brings depth and breadth to the philosophical debate. A group of distinguished philosophers, comprising both physicalists and their critics, consider a wide range of issues including the historical genesis and present justification of physicalism, its metaphysical presuppositions and methodological role, its implications for mental causation, and the account it provides of consciousness.