Necessity

Chapter 5 develops and defends an original account of the necessity constraint on the use of defensive force. The chapter argues that the necessity condition is grounded in the right to be rescued from harm when this rescue can be provided at reasonable cost. The chapter argues that even wrongful attackers have the right to be rescued from serious harm when others can do so at reasonable cost, and this right explains why there is a necessity condition on the permissible use of defensive force. The chapter also offers criticisms of competing conceptions of the necessity condition, as well as offering a particular view regarding the relationship between necessity and liability.