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...