Social action is central to social thought. This centrality reflects the overwhelming causal significance of action for social life, the centrality of action to any account of social phenomena, and the fact that conventions and normativity are features of human activity. This book provides philosophical analyses of fundamental categories of human social action, including cooperative action, conventional action, social norm governed action, and the actions of the occupants of organizational roles. A distinctive feature of the book is that it applies these theories of social action categories to some important moral issues that arise in social contexts such as the collective responsibility for environmental pollution, humanitarian intervention, and dealing with the rights of minority groups. Avoiding both the excessively atomistic individualism of rational choice theorists and implausible collectivist assumptions, this important book will be widely read by philosophers of the social sciences, political scientists and sociologists.