When groups feature in political philosophy, it is usually in one of three contexts: the redressing of past or current injustices suffered by ethnic or cultural minorities; the nature and scope of group rights; and questions around how institutions are supposed to treat a certain specific identity/cultural/ethnic group. What is missing from these debates is a comprehensive analysis of groups as both agents and objects of social policies. While this has been subject to much scrutiny by sociologists and social psychologists, it has received less attention from a normative and philosophical point of view. This volume asks: what problems are posed to political philosophy by a collection of individuals who act or are treated in a collective way? Focusing not only on ways in which institutions should treat groups, but also on the normative implications of considering groups as possible social agents, when acting either in vertical relations with the state or in horizontal relations with other groups (or individuals), this book explores these issues from both theoretical and practical perspectives. Contributors address both the nature of political and social philosophy itself, and the ways in which specific issues - affirmative action, race, religion and places of worship, the rights of states - have become political and social priorities.