Building on many years of scholarship, Matthew H. Kramer sets out his definitive philosophical investigation of rights and rights-holding with this monograph, as he sometimes revisits and modifies his previous positions. Beginning with the analytical schema propounded by the American legal theorist Wesley Hohfeld, the book provides a defence of the proposition that every claim-right with a certain content is correlative to at least one duty with the same content and that every duty with a certain content is correlative to at least one claim-right with the same content. The volume then addresses the longstanding debates over the nature of right-holding, with a sustained defense of the Interest Theory and with some innovative critiques of the Will Theory. Finally, it considers the ethical and analytical questions involved in determining who can hold claim-rights at all. It argues that the beings capable of holding claim-rights include not only human adults of sound mind but also all other living human beings, many dead people, and all future generations of people, along with most non-human animals. Addressing some major topics within moral, legal, and political philosophy,Rights and Right-Holding: A Philosophical Investigation will be a key work for philosophers and academic lawyers alike.