The first of these views, advocated by Spinoza and held in our own day by Bradley and many other philosophers, is called monism ; the second, advocated by Leibniz but not very common nowadays, is called monadism , because each of the isolated things is called a monad . Both these opposing philosophies, interesting as they are, result, in my opinion, from an undue attention to one sort of universals, namely the sort represented by adjectives and substantives rather than by verbs and prepositions.