Defence Against Parfit’s Torturers

Abstract

Abstract In the literature on ‘moral mathematics’ prompted by the section with that title in Derek Parfit’s Reasons and Persons, one issue is whether, and if so to what extent, it is wrong to cause a negligible harm to each of a large number of people, and in particular whether doing so could ever be as seriously wrong as causing a substantial harm to one person. The topic in this chapter is the closely related issue of proportionality in defence against those who would inflict only such tiny harms, though on a large number of victims. For example, might a person who would otherwise inflict a tiny harm on each of a large number of people be liable to be killed in defence of those people? The chapter suggests that such a person seems liable to be killed in some cases but not in others, depending on what other people might be doing or on other facts about the context in which the harms would occur. It reviews a range of examples involving the infliction of tiny harms, including Parfit’s example of the Harmless Torturers, that reveal some surprising facts about the conditions and limits of liability to defensive harm.