What is Immanence?

One of the terminological constants in Deleuze's philosophical work is the word ‘immanence’. That this ancient and well-travelled notion of immanence is held to have been given new life and new meaning by Gilles Deleǔe is evidenced in much recent secondary literature on continental philosophy, as well as in recent key texts on political philosophy, such as Michael Hardt and Antonio Negri's turn of the millennium tome Empire, which takes up and deploys the Deleuzian theme of ‘the plane of immanence’ as a means for thinking outside of the distorted norms of contemporary capitalist society. In the rare explicit directions Deleuze gives for reading his philosophy, he often focuses on the theme of ‘immanence’. For instance, in a 1988 interview with Raymond Bellour and François Ewald, he says that ‘setting out a plane [plan] of immanence, tracing out a field of immanence, is something all the authors I've worked on have done, even Kant – by denouncing any transcendent application of the syntheses of the imagination’ (N 144). In Spinoza and the Problem of Expression (translated as Expressionism in Philosophy: Spinoza, we read how a ‘specifically philosophical concept of immanence … insinuates itself among the transcendent concepts of emanative or creationist theology’, with its own ‘specifically philosophical “danger”: pantheism or immanence’ (EPS 322). In their final major work, What Is Philosophy?, Deleuze and Guattari proclaim enigmatically that ‘it is a plane of immanence that constitutes the absolute ground of philosophy, its earth or deterritorialization, the foundation upon which it creates its concepts’ (WP 41); moreover ‘freedom exists only within immanence’ (ibid. 48). So what is ‘immanence’?