Abstract

Boundaries are the outermost parts of objects, with a twofold function: dividing objects from their environment and allowing objects to touch each other. The task of this paper is to classify and describe the human dependent boundaries, i.e., the so-called fiat boundaries, on the basis of the seminal work by Smith and Varzi. Roughly, a fiat boundary is a marker of discontinuity between two or more objects which relies on a human function assignment, usually called ‘fiat act’. In what follow I outline the different ways in which human beings make fiat boundaries out of nature. Along the way I shall give evidence that a theory of fiat boundaries can be useful to take up as a starting point for doing metaphysics and for giving an account of the ontology of both the material and the social world. The chief goal is to shed light on how some objects depend upon human beings: either in a deliberative or non-deliberative way; either a priori or a posteriori; by means of individual or collective act; by modal strength, namely possible and necessary boundaries.