 By the same token, Cook Wilson thought that this line of reasoning shows that Russell’s paradox of the class of all classes that do not contain themselves (Russell 1903, chap. X) is a “mere fallacy of language” (SI, cx). He thus argued at length (SI, §§ 422–32), including in his correspondence with Bosanquet (SI, §§ 477–518) that there can no more be a ‘class of classes’ than ‘universalness’ could be a ‘universal of universals’ and that a class can no more be a member of itself than ‘universalness’ could be a particular of itself: the implied ‘universal of universals’ or ‘universalness’, of which universals would be the particulars, would be a particular of itself, which is, Cook Wilson claims, “obviously absurd” (SI, 350). For bad reasons such as these, Cook Wilson was contemptuous of what he called “the puerilities of certain paradoxical authors” (SI, 348). He even wrote to Bosanquet: