UC Irvine

Abstract: “Thing” in the titular question of this paper should be construed as having the utmost generality. In the relevant sense, athingjust is anentity, anexistent, abeing. The present task is to say what a thingof any categoryis. This task is the primary one of any comprehensive and systematic metaphysics. Indeed, an answer provides the means for resolving perennial disputes concerning theintegrityof the structure in reality—whether some of the relations among things arenecessarymerely given those relata themselves—and theintricacyof this structure—whether some things are more or lessfundamentalthan others. After considering some reasons for thinking the generality of the titular question makes it unanswerable, the paper propounds the methodology,original inquiry, required to answer it. The key to this methodology is adopting a singular perspective; confronting the world as merely theimpetus to inquiry, one can attain an account of what a thing must be.Radical ontologyis a systematic metaphysics—broadly Aristotelian, essentialist, and nonhierarchical—that develops the consequences of this account. With it, it is possible to move past stalemate in metaphysics by revealing the grounds of a principled choice between seemingly incommensurable worldviews.