I’m giving a talk entitled “Existence, Definedness and the Semantics of Possibility and Necessity” at a Workshop on the Philosophy of Timothy Williamson at the Asian Workshop in Philosophical Logic and the Taiwan Philosophical Logic Colloquium at the National Taiwan University.
Abstract: In this talk, I will address just some of Professor Williamson’s treatment of necessitism in his Modal Logic as Metaphysics. I will give an account of what space might remain for a principled and logically disciplined contingentism. I agree with Williamson that those interested in the metaphysics of modality would do well to take quantified modal logic—and its semantics—seriously in order to be clear, systematic and precise concerning the commitments we undertake in adopting an account of modality and ontology. Where we differ is in how we present the semantics of that modal logic. I will illustrate how proof theory may play a distinctive role in elaborating a quantified modal logic, and in the development of theories of meaning, and in the metaphysics of modality.