 Trope theories usually explain the fact that two things ‘share’, say, a particular shade of yellow with help of a resemblance class. Here, Cook Wilson parts company, claiming that the universal is “something identical in the particulars, which identity cannot be done away by substituting the term similar for same” (SI, 344 &amp; 347). Although the universal is, according to Cook Wilson, nothing outside its particularizations, it is claimed to be a “unity and identity in particulars” or a “real unity in objects” (SI, 344). It is meant to possess an ‘intrinsic character’ (SI, 342n. &amp; 351), for which Cook Wilson reluctantly introduced a technical term: “the characteristic being of the universal” (SI, 342). But he introduced no equivalent to Stout’s fundamentum relationis or ‘distributive unity of a class’ (Stout 1930, 388), because he did not define the universal in terms of membership of a class. Although he recognized that universals have an extension, i.e., the “total being of the universal” composed of the “whole of the particulars as the particularization of this unity”, he did not identify the universal with it (SI, 338).