Abstract
This chapter focuses on question of the relation of properties to particulars. It considers three theories of facts: as tropes, as states of affairs, and as nexuses between particulars and universals, noting that in each case, facts turn out to be particulars of a kind. The chapter investigates the question of substances, considering two accounts about the relationship between substances and properties, namely, Relational and Constituent Ontology. Substances would have a surprising degree of metaphysical complexity. According to Constituent Ontology, properties are literally parts of substances they characterize. According to Relational Ontology, in contrast, properties are separate things, extrinsically related to their instances. The chapter examines two versions of Constituent Ontology, Bundle Theory and Substrate Theory. Classical Bundle Theory purports to reduce substances to bundles of universals. The chapter also examines Nuclear Bundle Theory that faces an especially virulent form of the problem of Individuation.