A One Category Ontology

An ontology is defined by its fundamental categories. Following Peter van Inwagen (2011), take divisions between fundamental categories to mark “real divisions between things” that determine the basic categorical structure of the world. Speaking metaphorically, the fundamental categorical structure of the world carves the world at its fundamental joints. The project of determining the fundamental categorical structure of the world descends (arguably) from Aristotle, who started by dividing the realm of being into at least two fundamental categories: the fundamental category of particulars, or the present-in, and the fundamental category of universals, or the said-of. This gives the world a certain sort of structure, built from things with two different natures, things with the nature of being a bearer of properties or being a particular, and things with the nature of being borne by particulars. This supports a two category ontology. The idea is that the world exhibits this fundamental distinction between natures, a distinction between individuals or bearers and the properties and relations these things bear. The notion of understanding the ontological structure of the world in terms of divisions between natures is also deeply embedded in the Lewisean notion of naturalness, and is extended in Theodore Sider’s (2012) view that the world has fundamental quantificational structure. I defend a one category ontology: an ontology that denies that we need more than one fundamental category to support the ontological structure of the world. Categorical fundamentality is understood in terms of the metaphysically prior, as that in which everything else in the world consists. One category ontologies are deeply appealing, because their ontological simplicity gives them an unmatched elegance and spareness. I’m a fan of a one category ontology that collapses the distinction between particular and property, replacing it with a single fundamental category of intrinsic characters or qualities. We may describe the qualities as qualitative characters