 There is no limit to the number of languages we could conjure up in the abstract using the first mode of individuation. But only a small number of these abstract objects will be realized in the sense of being describable in the second mode—as possessed, known, spoken, understood, or in some other respect used by some individual or population. If we pick out a language as the language of some individual, and believe we can specify its properties by reference to the intrinsic properties of that individual, then we are picking out an idiolect. If on the contrary we either specify it by reference to a community, or specify it by reference to an individual but can only determine its properties by looking to their wider social environment (identifying salient linguistic authorities, for example), then we are picking out a social language.