This is a new edition of a hugely popular textbook, which has been designed to introduced students to criminal law through a study of the principles and policies underlying it. Exploring the major spheres of criminal liability, the book raises questions about the proper limits of the criminal law, the relative seriousness of harms, the various principles grounded in fairness to individuals, policies designed to further the aims of the criminal law, and ideas of criminal culpability. The second edition has been thoroughly revised and updated to include discussion of all major developments since 1991, and has been expanded to provide more coverage of substantive law.