 After the first four postulates, we find the theory of the faculties, which will be Deleuze’s account of what it means to be “forced” to think in differential rather than identitarian terms. To free a notion of “difference in itself” such that difference need not be thought on the basis of a prior horizon of identity, Deleuze looks for an “encounter,” a sensation that cannot be thought, that cannot find the empirical category under which an object can be recognized, and thus forces the “transcendent exercise” of the faculty of sensibility, when something can only be sensed.