The Metaphysical Basis of Logic

Abstract

In this dissertation, I argue for a novel view in the metaphysics and epistemology of logic, and then answer some of the questions that the view raises. I suggest, first, that logical realism is true—that there is logical structure in the world. It is this logical structure that makes us correct in using certain logics, but not others, to theorize about the world. I then argue that this logical structure is deeply unfamiliar. It doesn't at all resemble any of our concepts, and it doesn't resemble the structure of our languages. I go on to address some of the worries and questions that this raises. First, I argue that the logical realist

should think of logics that are candidates for capturing worldly structure as triadic: as consisting in a syntax, a semantics, and a target that that syntax and semantics are jointly aiming to represent. I give an account of when we can know that syntax and semantics as successfully representing the same target, and what we can learn in such cases. Next, I turn to the question of how, if the view I argue for is correct, we can distinguish between metaphysical theories that realists typically take to be saying different things about the world. I show that there is an account of metaphysical equivalence that is

consistent with us not knowing what worldly logical structure (or fundamental reality in general) is like, but which still allows us to distinguish between such theories.