The first of two goals of this book is to provide a critical survey of the major debates about free will and determinism of the past quarter century, a period during which there have been many new developments in the study of this ancient philosophical problem. The book seeks to acquaint readers with current debates and new developments on free will, showing their relevance to broad contemporary concerns in ethics, politics, science, religion, and humanities. The second goal of the book is to defend a traditional view of free will and moral responsibility, according to which both are incompatible with determinism. In response to claims that such a traditional view of free will (often nowadays called an “incompatibilist” or “libertarian” view) has no place in the modern scientific picture of the world, the book argues that a nondeterminist conception of free will can be defended without the usual appeals to obscure or mysterious forms of agency and can be reconciled with recent developments in the sciences – physical, biological, neurological, cognitive, and behavioral. The book also discusses the relation of free will to other important topics, such as morality, dignity, rationality, creativity, autonomy, desert, causation, consciousness, alternative possibilities, explanations of action, reasons for action, practical reason, weakness of will, incommensurability of values, and others.