Abstract

A categorial dualist, John Heil includes substance and property in his ontology. But in his case for dualism, there are pressures to drop substance or property and endorse monism, as well as pressures to include both. Rather than defend monism or dualism, I introduce a distinction. If a category is a kind of entities, then substance is the only category. If an accounting of categories is to include property, then property must enter not as a kind of entities but a kind of aspects of reality. The distinction is worth deploying for two main reasons. First, it makes plain an important difference between substances and properties, which categorial dualism obscures. Second, the distinction reduces puzzlement about whether and how to include relation in an accounting of categories.