A Semantic Constraint on the Logic of Modal Conditionals
Zsófia Zvolenszky · PhilPapers (PhilPapers Foundation) · 2006
Capturing the semantics of modal discourse (talk of what’s necessary/possible or required/ allowed) hardly seems possible without possible worlds.∗ And yet one of their most basic applications turns out to be irreparably flawed when it comes to certain modal conditionals. If we want to make amends, we have to fundamentally revise the semantics of modal conditionals. My focus is on deontic logic, a special kind of modal logic about what laws/norms allow and require, be they traffic laws, moral laws, or health considerations. But the arguments carry over to bouletic modality, about what someone’s desires allow and require, as well as circumstantial (or dynamic) modality, about what a given set of circumstances require. Conversational context decides various details about interpreting modal expressions (Kratzer 1977, 1981, 1991): whether the modal expression at hand is deontic, epistemic, bouletic, or some other; and if it is, say, an epistemic modal, whether the relevant epistemic background concerns my knowledge, or someone else’s. Three lead characters are featured: Symptom, Culprit, and Link. In their order of appearance: