Evidence Sensitivity in Weak Necessity Deontic Modals

Kolodny and MacFarlane () have made a pioneering contribution to our understanding of how the interpretation of deontic modals can be sensitive to evidence and information. But integrating the discussion of informationsensitivity into the standard Kratzerian framework for modals suggests ways of capturing the relevant data without treating deontic modals as “informational modals” in their sense. I show that though one such way of capturing the data within the standard semantics fails, an alternative does not. Nevertheless I argue that we have good reasons to adopt an information-sensitive semantics of the general type Kolodny and MacFarlane describe. Contrary to the standard semantics, relative deontic value between possibilities sometimes depends on which possibilities are live. I develop an ordering semantics for deontic modals that captures this point and addresses various complications introduced by integrating the discussion of information-sensitivity into the standard semantic framework. By attending to these complexities, we can also illuminate various roles that information and evidence play in logical arguments, discourse, and deliberation. *anks to Fabrizio Cariani, Nate Charlow, Jan Dowell, Kai von Fintel, Allan Gibbard, Irene Heim, Angelika Kratzer, Rich omason, and audiences at MIT, the  ESSLLI Student Session, and the  Central APA deontic modals session for helpful discussion, and to anonymous reviewers fromESSLLI and the Journal of Philosophical Logic for their valuable comments. anks especially to Eric Swanson for extensive discussion and detailed comments on previous dras.