Book excerpt: Collective Action, Philosophy and Law brings together two important strands of philosophical analysis. It combines general philosophical inquiry into collective agency with analyses of specific questions about plural entities and activities in the legal domain. These are issues of growing interest in areas of philosophy like action theory and social ontology, as well as in philosophy of law. The book contains 13 original chapters written by an international team of leading philosophers and legal theorists and is divided into 4 parts: The nature of law and of legislative intention Practical reasoning and duties Causality, blameworthiness and responsibility Citizens, states and institutions. These sections cut across, and build on, different accounts to advance the debate on classical and new issues in collective agency. Each part also features legal-philosophical analyses that draw on general accounts of collective agency to cast new light on the law, descriptive as well as normatively. Collective Action, Philosophy and Law is the first major interdisciplinary and multi-authored work bridging legal and philosophical approaches to collective agency. As such, it is essential reading for students and researchers of philosophy of law, ethics, political philosophy, jurisprudence and legal theory.