Life in Groups: How We Think, Feel, and Act Together develops and applies the author's perspective on topics to do with joint commitment. This kind of commitment unifies those who participate in it, guides their actions going forward, and determines their relations to one another in important ways. In particular, it grounds in each of the parties a set of rights and obligations of a particular kind. Thirteen essays are gathered in this volume, together with a substantial introduction, which serves both to explain joint commitment for those unfamiliar with it and to advance discussion in light of some questions it has prompted, and a reflective conclusion. The essays range over collective beliefs and intentions; rational choice and preference; group lies and corporate misbehavior; remorse and other emotions; rights, obligations, and freedom.