Abstract

The term “crimes against humanity” is indissolubly linked to the Nazis’ genocidal slaughter of six million European Jews and to other mass atrocities perpetrated by the Third Reich. It was only after the defeat of the Nazi regime that international law took the step of authoritatively declaring such atrocities to be prohibited, and the prohibition marked an important development in the moral and legal consciousness of humankind. But what are crimes against humanity? In what sense are they “against humanity?” And how are they distinct from ordinary criminal offenses like homicide and assault?These questions are, in part, questions of law, to be answered by examining authoritative legal materials, including international agreements and the opinions of international courts. But the questions are not only legal questions, because the ideas of crimes against humanity and genocide have overflowed the narrow channels of law and entered into the discourse and thinking of political philosophers and the public at large. The law should be the starting point of systematic reflection on the nature of crimes against humanity and genocide. But it should not be the end.This article examines the origins of the categories of crimes against humanity and genocide and the differing legal, philosophical, and public understandings of those categories that have developed since the end of World War II. It argues that those crimes are not distinguishable from ordinary offenses like homicide and assault by being “against humanity” in any literal sense. However, the acts that fall under the categories of crimes against humanity and genocide are distinguishable in other ways, and entrenched facts of human history and psychology justify the criminal prohibition of those acts.