Supererogation: Evidence for Exhaustivity in Deontic Reasoning

Abstract

This paper revisits the paradox of supererogation which remains problematic for extant theories of deontic modality. I build on Lassiter (2011, 2017) and claim that a simple exhaustification of the expected utility-based semantics resolves the problem. Independent evidence comes from Korean, where expressions conveying modal necessity morphosyntactically encode exhaustivity.