Gilles Deleuze (1925–1995) was a Sorbonne-trained professor of philosophy who had written rigorous monographs on Hume, Spinoza, Nietzsche, and Bergson, firmly inside the classical French university tradition. Félix Guattari (1930–1992) was a Lacanian-trained psychiatrist working at the La Borde clinic on radical experiments in institutional psychotherapy and moving between the Communist Party and militant intellectual circles. They met in 1969; their 1972 Anti-Oedipus offered a productive, positive theory of desire against psychoanalysis's model of 'lack', and became the most sensational philosophy book of the post-May 1968 moment. Eight years of joint work later, in 1980, A Thousand Plateaus appeared as its far more sprawling, far stranger sequel.

The book deliberately makes itself hard to read. It consists of fifteen 'plateaus', each with a date in its title — '1227: Nomadology', '1837: Of the Refrain', '7000 B.C.: Apparatus of Capture'. These dates are not a hierarchical chronology but historical knots where the concepts thicken. The reader can begin from any plateau; there is no thesis assembled at the centre, only lateral connections. This form is the book's central concept made flesh — the rhizome: a horizontal, multiply entered, cuttable and reattachable network, against the vertical hierarchy of root, trunk, and branch.

A cluster of further concepts is woven around the rhizome. Deterritorialization and reterritorialization name the continuous making and unmaking of ties to a ground — capitalism, language, desire all unbind and rebind at once. Assemblage (agencement) names the temporary working arrangements of heterogeneous parts — bodies, words, institutions. The war machine is a force exterior to the state, coming from the nomad, transformed when the state internalises it. Abstract machines are the productive matrices beneath forms. None of these is a structure; all are processes, flows, becomings. Against Lacan's lacking subject, desire is not filling an absence but producing the world.

The book's reach went well beyond philosophy. Foucault said of Anti-Oedipus that 'perhaps this century will be known as Deleuzian'; A Thousand Plateaus seemed to confirm it, circulating through architecture (Eisenman, Lynn), digital theory (Hardt and Negri's Empire uses their vocabulary directly), design, performance, and the new materialism of Manuel DeLanda, Rosi Braidotti, and Jane Bennett. The critiques are not absent: that the proliferation of concepts replaces rigorous argument, that metaphor stands in for analysis. Even so, A Thousand Plateaus remains one of the three or four books that drew the map of late-twentieth-century continental philosophy — and, in just the way its authors hoped, it is used more than it is read, cut up and re-spliced, a rhizome in practice.