There may be circumstances in which it is morally justifiable intentionally to kill a person who is morally innocent, threatens no one, rationally wishes not to die, and does not consent to be killed. Although the killing would wrong the victim, it might be justified by the necessity of averting some disaster that would otherwise occur. In other instances of permissible killing, however, the justification appeals to more than consequences. It may appeal to the claim that the person to be (...) killed has acted in such a way that to kill him would neither wrong him nor violate his rights, even if he has not consented to be killed or to be subjected to the risk of being killed. In these cases, I will say that the person is liable to be killed. Although I borrow the notion of liability from legal theory, and although much of what I say will be informed by the literature on liability in both tort law and criminal law, my concern in this article is with moral rather than legal liability. (shrink)