Worlds, Counterparts and Modality

Abstract

This thesis is about Counterpart Theory (CT), which is a theory of translation that renders expressions of quantified modal logic (QML) into expressions of a non-modal first-order language. I defend three main claims. First, through the formulation of the translation in terms of a formal semantics for quantified modal logic, I argue that CT should be considered a formally flexible framework where one can obtain one’s desired modal logic by manipulating the counterpart relation as needed. Secondly, through the distinction between the object language and the target language of the translation, I reply to a family of objections against the theory in the recent literature, which claim that the counterpart-theoretic translation fails in light of some modal criteria. Finally, I explore some reductionist metaphysical theories that are compatible with CT and argue that the combination of CT, understood as a minimally applied theory, with axiom-based neo-conventionalism brings the best prospects for modal reductionism.

Date of Award	1 Oct 2022
Original language	English
Awarding Institution	King's College London
Supervisor	Jessica Leech (Supervisor) & Carlo Nicolai (Supervisor)