The next event is on Friday, May 8th:
Joint DIP-LIRa session: Paolo Santorio
Speaker: Paolo Santorio (University of Maryland, College Park)
Date and Time: Friday, May 8th 2026, 16:00-17:30
(Note the different weekday and time!)
Venue: ILLC Seminar Room F1.15, Science Park 107 and online.
Title: Modality and the Grain of Possibility
Abstract. On standard theories, the basic units of modal discourse are possible worlds, construed as maximal consistent states of affairs. I argue that we should switch to a semantics on which the basic modal entities are possibilities, in the sense of possibility developed by Humberstone and Holliday. Possibilities are analogous to worlds, but may be incomplete: they may leave some propositions unsettled. Using possibilities allows us to model a breed of indeterminacy that affects specifically modal claims, thus solving a number of open puzzles. In particular, I show that Ninan’s past-future asymmetry, the problem of counterfactual skepticism, and puzzling phenomena related to the assertion of will-claims can all be explained in a natural way in a possibility framework. The key feature of the new system is that two sentences may be equivalent in the sense that they are true throughout the same region of logical space, but still differ semantically in that they divide up that region in different ways.
More upcoming events:
- Friday, May 22nd, 16:00 - Joint DIP-LIRa session: Adam Bjorndahl
- Thursday, May 28th, 16:30 - LIRa session: Tianyi Chu