This magisterial work is the first comprehensive study of the ethics of killing, where the moral status of the individual killed is uncertain. Drawing on philosophical notions of personal identity and the immorality of killing, McMahan looks carefully at a host of practical issues, including abortion, infanticide, the killing of animals, assisted suicide, and euthanasia.

Killing a person is in general among the most seriously wrongful forms of action, yet most of us accept that it can be permissible to kill people on a large scale in war. Does morality become more permissive in a state of war? Jeff McMahan argues that conditions in war make no difference to what morality permits and the justifications for killing people are the same in war as they are in other contexts, such as individual self-defence. This view is radically at odds with the traditional theory of the just war and has implications that challenge common sense views. McMahan argues, for example,...