Titel: Some Necessary Revisions: On Modality and Belief Revision 

Abstract: I propose an extension of Thomasson's modal normativism; the view that the function of metaphysical modal vocabulary is to enable the conveyance and negotiation of semantic norms. But, as I argue, for modal vocabulary to fulfil this function, modal claims must express descriptive information in some sense. I propose an account of the rules governing alethic modal claims in terms of hypothetical belief revision. Essentially, we ought to accept a claim that P is possible or necessary if we would accept it under some or all hypothetical changes in belief respectively. Adopting this addition has several upshots. First, it allows us to extend the normativist account to alethic modality in general and explain how such modalities can be ordered in terms of strength. Second, it provides a normativist replacement for possible worlds as a system of semantics for modal logic. Finally, I discuss how the present account makes every question about necessity or possibility either a conceptual or an empirical matter.