Paint, Substance & Substrata

"Some philosophers, such as Armstrong, Plato, and myself believe that at least some categories are metaphysically real and are thus as realists about properties. For example, if mass is a real quality, then entities with mass are grouped into that category in virtue of possessing that metaphysical property. A realist does not need to accept that all categories have a metaphysical foundation."

"When talking about particulars being in categories, there are two general ways to view this. One is a matter of grouping: the property is what puts an entity into that category. There is also the matter of the entity being what it is in terms of the quality. These two can amount to the same thing but can be distinguished conceptually."

"For example, there is what it is for a green thing to be in the category of green things and the matter of what it to be green. Again, one might determine that these amount to the same thing. To illustrate, Plato would (probably) say that the Form of Beauty groups beautiful things into that category and makes a beautiful individual beautiful."

The classic problem of universals asks in virtue of what a particular is a member of a category. Some philosophers endorse metaphysical realism about properties, holding that certain properties (for example, mass) are real qualities that ground category membership. Not all categories require metaphysical grounding; race, gender, and the status of U.S. citizenship are treated as social constructs rather than metaphysical entities. Category membership can be viewed as grouping by a property or as the entity’s instantiation of a quality, distinctions that can coincide or be separated. Epistemic questions and alternatives to property realism are set aside while attention turns toward substances and substrata, with substance defined as existing independently of other entities.

Read at A Philosopher's Blog