Uwe Steinhoff

Rights forfeiture or liability are not a path to the permissibility of self-defense (not even barring extraordinary circumstances), and the necessity condition is not intrinsic to justified self-defense. Rather, necessity in the context of justification must be distinguished from necessity in the context of rights forfeiture. While innocent aggressors only forfeit their right against necessary self-defense, culpable aggressors also forfeit, on grounds of a principle of reciprocity, certain rights against unnecessary self-defense. Yet, while culpable aggressors would therefore not be wronged by certain unnecessary defensive means, the use of such means against them would still not be justified. The underlying rationale of this necessity requirement lies not in the rights of the aggressor, but in an agent-relative requirement to take fair precautions against violating the rights of the innocent. This concern is also expressed in the necessity criterion defended and formulated in this paper, which is very harsh on aggressors. To wit, the necessity condition for justified self-defense must not be interpreted as requiring the employment of literally the least harmful means or of means that the defender reasonably believes to be, literally, the least harmful ones. What he must believe about the properties and possible effects of the means he employs is something that is much less demanding. Finally, the necessity condition of justified self-defense is also harsh (on the aggressor) in not implying a “success condition” worth its name.