Since its publication over a decade ago, A Companion to Metaphysics has established itself as the leading one-volume reference resource in the field. This extended and revised new edition brings the Companion up to date. A new section of longer review essays focuses on the major topics that continue to have an abiding centrality for the field and which have seen significant developments in recent years, including Fictional Entities, Individuation, Persistence, Realism & Anti-realism about Abstract Entities, as well Causation, Freedom of the Will, the Mind/Body Problem, Modality, and Space & Time. In addition the central A-Z section, consisting of nearly three hundred entries, has been extended with new entries on emerging topics and major metaphysicians and the existing entries have been brought up to date where necessary. Written by leading figures in the field and offering comprehensive coverage of both historical and contemporary metaphysics and from analytic and continental traditions, the entries in this extensively cross-referenced volume combine to form a complete and up to date reference guide for student and professional alike.