Gilles Deleuze is the poststructuralist who is closest to what might be called the ‘traditional’ problems and approaches of philosophy. As he happily explains in a 1990 letter to Jean-Clet Martin, ‘I consider myself a classic philosopher … I believe in philosophy as system.’ This is not to say that he defends traditional conclusions. Rather, he aims to radically reorientate thought away from its historical privileging of identity and its accompanying representational model of thought – what he calls the ‘image of thought’ – to an ontology and style of thinking based on a privileging of difference. This affirmation of difference over the identity that has long dominated Western thinking is often taken to be a foundational claim of poststructuralist thought. Rather than appeal to and depend upon an ahistoric, fixed, substantial, singular essence or principle to define things, one of the recurring themes of poststructuralist thought is that it is necessary to think of them as differentiated and differentiating. Deleuze offers a particularly sophisticated engagement with and justification for such an approach that involves the development of a radically innovative methodology that aims at nothing other than a complete revolution in Western thought.

Given the foundational nature of Deleuze's critique of identity, it is not surprising to find that it has implications for the subject. Whereas the subject has historically been thought to be defined by a fixed, ahistoric essence and, since Descartes, has been assumed to be the foundation of thought, Deleuze's affirmation of difference decentres the subject and, in so doing, radically undermines the foundationalism and essentialism that have traditionally been attributed to it. Politically speaking, he advocates a movement away from ahistoric, universal goals, teleological historical processes and, generally speaking, a ‘macro’ approach to political change, to a ‘micro’ one in which the focus turns to the continuous alterations to the ontological underpinnings of political regimes, as a means of undermining any affirmation of the legitimacy of a single political regime.