What should should mean

One analysis of non-deontic should treats it as having less-than-universal quantification over the epistemically accessible worlds – the worlds that, for all the speaker knows, could be the actual world. This analysis is based on the intuition that should assertions are weaker than are assertions of epistemic must sentences. Problems with the traditional analysis, however, indicate that there must be a different reason why these should sentences express weaker propositions. This paper argues that non-deontic should can involve either epistemic or metaphysical modality; both are weaker than epistemic must because should does not trigger a presupposition that things work out normally, while must does. An initially problematic attempt to extend this analysis to deontic should prompts a revision to Kratzer’s theory of modals, in which the division of labor between the modal base and the ordering source is rethought