   However, Russell himself warned against interpreting his position on relations this way, writing, “the doctrine that relations are ‘external’ … is not correctly expressed by saying that two terms which have a certain relation might not have had that relation. Such a statement introduces the notion of possibility and thus raises irrelevant difficulties” (BReal,  87). Complicating matters here are Russell’s own rather idiosyncratic and skeptical views about modal notions. Russell was dissatisfied with the prevailing conceptions of necessity and possibility among philosophers of his day, and argued instead against necessity (or possibility) as a fundamental or irreducible concept (see NP passim).