Boundaries: a study in the metaphysics of space

The dissertation is devoted to a study of the nature of spatial boundaries. Boundaries are what divide things from their surrounding, e.g. the surface of a table from the rest of the room.Part one of my dissertation is about the nature of boundaries. In chapter 1 I present some formal theories I assume: mereology, mereotopology, and theories of location. In chapter 2 I set forth the main features of boundaries and I argue that things depend upon their boundaries, contrary to the mainstream view. In chapter 3 I face the problem of contact, i.e. the problem of how two discrete things can touch each other. I argue that things can never keep in touch, whatever the structure of space is.In part two I defend the thesis according to which every boundary is of the fiat sort, i.e. it is mind independent. In chapter 4 I argue against bona fide boundaries, i.e. boundaries mind dependent. In chapter 5 I set forth a taxonomy of the various kinds of fiat boundaries in order to developing in details a general model of explanation of the fictional nature of boundaries and therefore of things. In part three I show how fiat boundaries can be adopted by urban planners for their different purposes.