This article considers the moral and practical considerations concerning whether recreational drug use should be prohibited by the criminal law in a liberal state. The meaning of drugs and decriminalization and the appropriate limits on the scope of the criminal law are discussed. The article addresses whether people should have a moral and political right to use drugs recreationally, and if so, under what conditions the state should have the power to deny or to curtail that right. Finally, the article explores the costs and benefits of criminalization and decriminalization to public safety, public health, and public welfare generally, and to the effective, honest, and orderly administration of law enforcement and criminal justice.