Antony Duff, Marc de Wilde, Louis Sicking, and Sofia Stok offer several criticisms of my “The Enemy of All Humanity,” but central to all of them is concern that labeling people hostis generis humani dehumanizes them, and invites murder or extrajudicial execution. In response I distinguish political, legal, and theoretical uses of the ancient label. I agree with the critics that the political use is toxic and the legal use is dispensable. However, the theoretical concept is crucial in international criminal law, which rests on the assumptions that the moral heinousness of core crimes makes them the business of all humanity. Furthermore, far from dehumanizing their perpetrators, calling them to account before the law recognizes that they are no different from the rest of humanity. This response also offers rejoinders to more specific objections raised by the critics.

Trationally, the term “enemy of all humanity” (hostis generis humani) referred to pirates. In contemporary international criminal law, it refers to perpetrators of crimes against humanity and other core. This essay traces the evolution of the concept, and then offers an analysis that ties it more closely to ancient tyrants than to pirates. Some object that the label is dehumanizing, and justifies arbitrary killing of the “enemy of humanity.” The essay admits the danger, but defends the concept if it is restricted to fair trials. Rather than dehumanizing its target, calling the hostis generis humani to account in a court of law is a way of recognizing that radical evil can be committed by humans no different from any of us.