Killing and rescuing: Why necessity must be rethought

This article addresses a relatively unexplored problem in the ethics of defensive killing. There is widespread agreement that defensive killing is subject to a necessity condition. One cannot justify killing if there is a better means to fulfil the goal that stands to justify killing. The problem is that, in any given case, there are often multiple ways to describe the goal and it is unclear which we should adopt. Our choice of description is critical to determining which acts count as relevant alternatives to killing. The article both presents a methodological approach for solving this problem, and, on the basis of the approach, advances a substantive position regarding which acts count as relevant alternatives. The methodological approach, which I term the “Comparative Approach”, involves comparing different descriptions to find the description that includes all and only those goals that, from the standpoint of the person using defensive force, are worth killing to achieve. The substantive position, which I term the “Revisionary View”, holds that an act of rescue can sometimes be a relevant alternative to killing even if it rescues different victims from a different threat or the same victims from a different threat. On the basis of the Revisionary View, the article holds that killing is much harder to justify than we would otherwise have thought.