The Modern History of Modal Logic
Spring 2025A graduate seminar following the origins and development of intensional semantics, from the proof-theoretic systems of strict implication S1–S5 developed by C.I. Lewis and Langford, through the debates over quantified modal logic between Barcan Marcus and Quine, to the semantic theories of Carnap, Kripke, and Prior. After criticizing the two-dimensional theories of Montague and Kaplan, the course defends a novel semantics for a bimodal logic validating the perpetuity principles, then turns to the selection, similarity, and imposition theories of counterfactuals of Stalnaker, D. Lewis, and Fine to motivate a unified hyperintensional framework.