Cruz Davis

Supersubstantivalists identify material objects with regions of spacetime. Accordingly, they take their view to be both more ideologically parsimonious than other substantivalists (dualists) because they can reduce location to identity with a region and they can explain why the mereological structure of objects mirrors the mereological structure of their locations (henceforth, “harmony”). However, I argue that these motivations for supersubstantivalism don’t hold water. Specifically, I argue that supersubstantivalists can only claim the aforementioned advantages just so long as they stand in a unique position to reduce location. But this depends on the illicit assumption that no possible spacetime structures have co-located regions – something falsified by the possibility of merely pseudo-metric spaces. Further, any alternative reduction is equally available to the dualist. Accordingly, this allows dualists to have the same explanation of harmony as the supersubstantivalist. As such, these considerations level the dialectical playing field between dualists and supersubstantivalists.

While there is considerable disagreement on the precise nature of material objecthood, it is standardly assumed that material objects must be spatial. In this paper, I provide two arguments against this assumption. The first argument is made from largely a priori considerations about modal plenitude. The possibility of non-spatial material objects follows from commitment to certain plausible principles governing material objecthood and plausible principles regarding modal plenitude. The second argument draws from current philosophical discussions regarding theories of quantum gravity and the emergence of spacetime. When it is appreciated what possible worlds these current theories commit us to, the possibility of non-spatial material objects will follow. Thus, either route will lead us to the possibility of non-spatial material objects. The significance of this result is that we need to revise our accounts of material objecthood to both accommodate these possibilities and the theories that lead to them.