Abstract

Dual-role approaches to reasons say, roughly, that reasons can relate to actions in two fundamentally different ways: they can either require conformity, or justify an action without requiring that it be taken. This paper develops a formal dual-role approach, combining ideas from defeasible logic and practical philosophy. It then uses the approach to shed light on the phenomenon of supererogation and resolve a well-known puzzle about supererogation, namely, Horton’s All or Nothing Problem.