Abstract

This chapter explores the relationship between a person’s liability to defensive harm and the necessity of harming her. Internalist accounts of liability hold that one can be liable only to harms that are necessary for averting a threat. Externalist accounts of liability hold that necessity is not internal to liability. The chapter proposes and defends proportionate-means externalism. This view holds that one can be liable to more than the least harmful means of averting a threat, but it also recognizes that only instrumental harms can count as defensive. As such, only these harms should be sanctioned by an account of liability to defensive harm. In cases involving culpable attackers, seemingly ineffective harms can actually count as a means of defending the victim’s moral standing. This observation should inform our understanding of a culpable attacker’s liability and her right to counterdefense.