Relative Necessity Reformulated with Jessica Leech

Abstract

This chapter discusses some serious difficulties for what it calls the standard account of various kinds of relative necessity, according to which any given kind of relative necessity may be defined by a strict conditional—necessarily, if C then p—where C is a suitable constant proposition, such as a conjunction of physical laws. It is argued, with the help of Humberstone (1981), that the standard account has several unpalatable consequences. It is argued that Humberstone’s alternative account has certain disadvantages, and another—considerably simpler—solution is offered. The proposed alternative takes seriously the idea that the standard account omits crucial information which, if suitably replaced, allows the problems to be solved.