Gilles Deleuze is one of the most infl uential post-war French philosophers. While his infl uence in the Anglo-American world began with the translation of his collaborations with Félix Guattari, Difference and Repetition has a good claim to be his philosophical masterpiece. It's diffi cult to situate Difference and Repetition within the philosophical tradition. Deleuze characterises his project as a ‘transcendental empiricism’, which suggests affi nities with eighteenth and nineteenth-century German idealist thought. Nonetheless, Deleuze presents an account critical of both the transcendental idealist characterisation of experience and its account of knowledge. Similarly, we fi nd strands of the early twentiethcentury phenomenological project both affi rmed and critiqued throughout Difference and Repetition. We can also see an ambivalent relationship to the structuralist tradition charted throughout the text, and a substantial engagement with the philosophies of science and mathematics. In this book, I have tried to present as many of these engagements as possible, but the emphasis is on Deleuze's own characterisation of himself as a ‘pure metaphysician’. That is, I take Deleuze to be giving us an account of the nature of the world, broadly construed. What makes his project appear almost unrecognisable when compared with traditional metaphysical approaches is that he is attempting to provide a metaphysics of difference. As we shall see, his claim is that when we take identity as prior to difference, exemplifi ed in the belief in judgement as the basis for philosophical enquiry, we are constrained to make a number of claims about the nature of the world and the nature of knowledge. These claims together form the traditional image of metaphysics. In Difference and Repetition, Deleuze renounces the priority of identity, which leads to a very different kind of metaphysical inquiry.