Epistemic Modality and Coordination under Uncertainty

Communication facilitates coordination, but coordination might fail if theres too much uncertainty. I discuss a scenario in which vagueness-driven uncertainty undermines the possibility of publicly sharing a belief. I then show that asserting an epistemic modal sentence, Might p, can reveal the speakers uncertainty, and that this may improve the chances of coordination despite the lack of a common epistemic ground. This provides a game-theoretic rationale for epistemic modality. The account draws on a standard relational semantics for epistemic modality, Stalnakers theory of assertion as informative update, and a Bayesian framework for reasoning under uncertainty.