Contrary to the views of Alasdair MacIntyre and others who assert that modern Western morality is in disarray, torn by incommensurable moral views, John Reeder believes that there is much agreement about taking and saving lives. Many people might, in fact, agree on the various circumstances in which the death of a person constitutes a violation of the right to life, or that people have a right to our help, especially a right to life-saving aid.

In Killing and Saving, Reeder analyzes five sorts of situations in which we are morally permitted or even obligated to take human life: e.g., when we repel an attacker who voluntarily "forfeits" the right to life; when we are confronted with "involuntary pursuit" or "material aggression"; when someone "yields" the right to life; when all will die if nothing is done, but some can be saved if others are killed; and when there is a "double effect" in which we take life as a foreseen but unintended consequence of attempt to achieve a greater good. Reeder argues that these (and closely related) categories account for many of our convictions ranging from abortion to infanticide, to starvation, to war. He also examines the concept of absolute or exceptionless right to life.

Reeder draws on a number of moral views, from theological ethics to Enlightenment notions of natural rights or respect for rational creatures. He does not attempt to argue for a foundation for the right not to be killed and the right to be saved. Rather, he focuses on the content of the convictions themselves and argues that where disagreements remain, such as the case of abortion, they can be accounted for by the way the rights in question are explained and justified.