Exploring the principles and values that should guide and limit the state's use of preventive techniques that involve coercion against the individual, this volume arises from a three-year study of Preventive Justice. The contributions examine whether and when preventive measures are justified, whether within or outwith the criminal law, and whether they signal a larger change in the architecture of security. Preventive measures include controversial crime control approaches such as pre-inchoate offences, pre-trial detention, restraining orders, and prevention detention of the dangerous. There are good reasons to justify state use of coercion to protect the public from harm, but while the rationales and justifications for state punishment have been extensively explored, the scope, limits, and principles of preventive justice have not received the same attention. This volume, written by world renowned scholars from different disciplinary backgrounds and jurisdictions, redresses the balance, assessing the foundations for the range of coercive measures that states now take in the name of prevention and public protection.