A Collapse Result in the Mereology of Properties

Abstract

I examine five principles about the metaphysics of properties, each of which has been defended in the literature: (1) the sum of properties is their corresponding conjunctive property, (2) the mereology of properties is classical, (3) properties are individuated by necessary co-instantiation, (4) sums of objects belonging to different categories do not belong to the category of any of their parts, and (5) there is at least a property necessarily instantiated by every individual. I prove that this package of views entails that there is exactly one property. Since this conclusion is highly implausible, I will discuss some ways of modifying the package in order to avoid it.