This week, Franz Berto is giving a talk introducing the logic of conceivability, after which we’ll decide the texts we’ll work on this semester.

Franz Berto: The Theory of Topic-Sensitive Intentional Modals

A Topic-Sensitive Intentional Modal (TSIM) is a two-place, variably strict modal with an aboutness or topicality constraint, of the form ‘X^φψ’ (read: ‘Given φ, the agent X’s that ψ’, X being some mental state or act). TSIMs do nice things for mainstream and formal epistemology, belief revision theory, and mental simulation theory. I present a basic formal semantics for TSIMs and explore three readings of ‘X^φψ’ one gets by imposing different constraints on their truth clauses: (1) as expressing knowability relative to information (‘Given total information φ, one is in the position to know that ψ’), inspired by Dretske’s insight that what one can know depends on the available (empirical) information;  (2) as a mental simulation operator (’In mental simulation starting with input φ, one imagines that ψ’) capturing features of mainstream mental simulation theories, like that of Nichols and Stich; (3) as a hyperintensional belief revision operator (‘After (statically) revising by φ, one believes that ψ’), reducing the idealization of cognitive agents one finds in doxastic logics and standard AGM. I close by mentioning developments of TSIM theory currently in progress.