The development of an international human rights jurisprudence on criminalization is in its relative infancy. Nonetheless, systematic examination of international decisions on acts engaging the criminal law reveals an emerging human rights approach to the acceptability, or not, of criminalization. This book provides an in-depth characterization of the reasoning and principles that underpin those decisions.The work builds upon and adds value to existing literature by bringing together two fields of study - international human rights law and criminal theory - that usually receive separate treatment. It provides an in-depth analysis of human rights criminalization jurisprudence and presents a systematic identification of underlying reasoning and concepts that influence international human rights decisions on criminalization. The work thus advances both fields independently, as well as providing an example of inter-(sub)disciplinary analysis. The book will be a valuable resource for academics and students working in the areas of International Human Rights Law, Criminal Law, and Moral Philosophy.