Deleuze, Gilles’s term, derived from language philosophy, for the specific criteria that determine that something is one kind of thing and not another. Because Deleuze uses it to theorize the ontology of literally everything, including affect, it is often mistakenly thought that intensity refers to a species of experience that is particularly intense. But this is false. The true origin of the term is the logical relation between intension and extension. If we take the colour blue as our example, the extension of blue is all the objects in the world that are blue, while intension is the specific set of characteristics that make a thing recognizable as blue. In this sense, intensity may also be understood, paradoxically enough, as the extension of difference. See also singularity.