Abstract

There are a number of different versions of Reductive Nominalism, versions distinguished by the way in which each accounts for facts about having and sharing properties. This chapter discusses three broad varieties of Reductive Nominalism: Predicate Nominalism, Class Nominalism, and Resemblance Nominalism. Class Nominalism identifies properties with classes or sets. Resemblance Nominalists come in two sub‐varieties, depending on whether they take the resemblance relation to hold between particular properties (called 'tropes') or particular things that have properties (ordinary particulars). Trope Theory comes in two varieties depending on whether one plumps for universals. It should not be difficult to see that Extreme Resemblance Nominalism is faced with Class Nominalism's extensionality problems, both the problem of contingent predication and the co‐extensive property problem. Resemblance Nominalists can reply by insisting on a distinction between a priori or conceptual equivalence and metaphysical equivalence. The chapter focuses on the extensionality problems for Class Nominalism.