 The concept of difference as a productive mechanism, rather than a negation of identity, is also a hallmark of postmodernism in philosophy.  Gilles Deleuze deploys this concept throughout his work, beginning with Nietzsche and Philosophy (1962, in English 1983), where he sets Nietzsche against the models of thinking at work in Kant and Hegel. Here, he proposes to think against reason in resistance to Kant's assertion of the self-justifying authority of reason alone (Deleuze 1983 [1962], 93). In a phrase echoed by Foucault, he states that the purpose of his critique of reason “is not justification but a different way of feeling: another sensibility” (Deleuze 1983 [1962], 94). Philosophical critique, he declares, is an encounter between thought and what forces it into action: it is a matter of sensibility rather than a tribunal where reason judges itself by its own laws (see Kant 1787, 9). Furthermore, the critique of reason is not a method, but is achieved by “culture” in the Nietzschean sense: training, discipline, inventiveness, and a certain cruelty (see Nietzsche 1887). Since thought cannot activate itself as thinking, Deleuze says it must suffer violence if it is to awaken and move. Art, science, and philosophy deploy such violence insofar as they are transformative and experimental. 