Face-to-face only:
Register by 11 Jan 2026: https://cloud.itsc.cuhk.edu.hk/webform/view.php?id=13724494

Enquiries:
Tel: 3943 7135
Email: philosophy@cuhk.edu.hk

Abstract:

Modalities are sometimes more than they appear to be, as they can have hidden semantic logical structures. In this talk, we propose a semantic framework for deontic logic based on the concept of “bundles” of quantifiers and normal modalities. The starting point is to treat strong permission as a bundle ∀◊ such that an action type alpha is permitted if and only if every token of alpha can be executed in some deontically ideal world. The resulting logic of permission not only satisfies desirable requirements found in the literature (such as free choice) but also predicts interesting new phenomena that align with our linguistic intuition. We then extend this framework with various kinds of deontic modalities such as obligation and prohibition, using negated action types. We give several sound and complete proof systems of the resulting deontic logics. If time permits, we will draw some connections with Fine’s truthmaker-based deontic logic.
(Based on joint work with Zilu Wang)

Delivered in English.
All are welcome.

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[Related Event] World Logic Day Workshop: Logic and AI (14 Jan 2026)

To celebrate World Logic Day, we are pleased to host a workshop featuring Prof. Wang Yanjing (Peking University) and Prof. Sinno Pan (Department of Computer Science and Engineering, CUHK), who will share their experiences in teaching and researching logic in the age of AI, followed by a panel discussion.

Date: 14 Jan 2026 (Wed)
Time: 2:00pm-5:45pm HK Time
Venue: Room 101, Fung King Hey Building (Limited seats. Registrations will be handled on a first come, first served basis.)

Register Link: https://cloud.itsc.cuhk.edu.hk/webform/view.php?id=13724719