The Metaphysician’s Motte-and-Bailey

Ilmari Hirvonen

Philosophers often think quite highly of what they are doing, and those engaged in metaphysics are no exception. Indeed, metaphysicians offer perhaps the clearest example of this attitude, for they frequently insist that their work is not only important but, in fact, necessary. After all, who could deny the self-evident truth that everyone has ontological commitments in the sense that everyone takes something to exist. All of us – or practically all of us – believe that there are chairs, people, money, atoms, and so on. This, it is claimed, already suffices to make metaphysics inevitable.

Now, of course it is obvious that the scientist and the layperson both make ontological commitments in this very general way. But from that alone one cannot directly infer that theories of tropes, grounding, essences, composition relations, gunk, real definitions, and the like are by the same token indispensable. Since it…