Abstract
This thesis explores methodological approaches to studying substantivalism in metaphysics and the philosophy of science. My primary aim is to show that it is only when these two disciplines come together, that we can hope to make progress with respect to discovering the true nature of the structure of space-time.
I begin by looking at Leibniz’s argument that substantivalism entails the possibility of qualitatively indiscernible worlds, which differ only with respect to how the material world is located in space-time. I explore whether there is anything more to the basis of this contention than non-naturalistic appeals to common sense and a priori metaphysical principles. I argue that there is, as a modern-day interpretation of Leibniz’s argument shows that substantivalism renders GTR indeterministic. I consider whether this problematic indeterminism arises as a result of a particular conception of substantivalism, or whether it follows from all formulations of substantivalism consistent with GTR, and to what extent it is our additional metaphysical commitments that are motivating the problem.