LanCog seminar: Sena Bozdag on common knowledge and publicity
Ricardo Santos
SEMINAR SERIES IN ANALYTIC PHILOSOPHY
2025-26: Session 27
Common Knowledge and Publicity
Sena Bozdag (University of Bayreuth)
5 June 2026, 16:00 (Lisbon Time – WET)
Faculdade de Letras de Lisboa
Sala Mattos Romão [C201.J] (Departamento de Filosofia)
Abstract: We study the relation between common knowledge and publicity, i.e. that certain events or facts are ”out in the open”, or ”public” in a group. Our contribution is conceptual and clarificatory. We point out, first, that while the iterative definition of common knowledge is central to the epistemic foundations of game theory, it is less so for theories of collective agency, that rather use “common knowledge” in the sense of publicity. Building on this observation, we propose to distinguish between internalist and externalist understandings of common knowledge and to associate the notion of publicity with the latter. This allows us to classify the different accounts of common knowledge that have by now been studied by logicians, game theorists, and philosophers, to defuse a recent debate in philosophy around the relation between common knowledge and publicity, and to put the emphasis on the conditions by which common knowledge and publicity emerge. (This is joint work with Olivier Roy.)
All are welcome, in-person!