Asserting epistemic modals

Abstract The paper formalizes a change of camera angle on the classic Stalnakerian account of assertion, foregrounding that the speaker is presenting herself as though she knows the sentence she’s uttered to be true, and deriving context update from a proposal that the context set be modified so as to become a member of the same property of epistemic states as the speaker’s. The resulting formalization is one on which often, but crucially not always, an assertion serves to propose that the context set be intersected with the denotation of the sentence that has been uttered. Rather than assigning ad hoc update effects to epistemic modals, exceptional updates for epistemic modals fall out of the interaction between the speaker-oriented epistemicity of epistemic modals and the speaker-oriented epistemicity of assertion. This circumvents arguments that disagreement over epistemic modals is fatal to a solipsistic contextualist account of their semantics. The model builds a bridge from truth-conditional semantics to expressivist update effects via a uniform conception of assertive update, and shows how relativist effects can be derived using a relativist illocutionary machinery, rather than a relativist semantic machinery.