In the United States today, the use or possession of many drugs is a criminal offense. Can these criminal laws be justified? What are the best reasons to punish or not to punish drug users? These are the fundamental issues debated in this book by two prominent philosophers of law. Douglas Husak argues in favor of drug decriminalization, by clarifying the meaning of crucial terms, such as legalize, decriminalize, and drugs; and by identifying the standards by which alternative drug policies should be assessed. He critically examines the reasons typically offered in favor of our current approach and explains why decriminalization is preferable. Peter de Marneffe argues against drug legalization, demonstrating why drug prohibition, especially the prohibition of heroin, is necessary to protect young people from self-destructive drug use. If the empirical assumptions of this argument are sound, he reasons, drug prohibition is perfectly compatible with our rights to liberty.