Gilles Deleuze was one of the most influential and prolific French philosophers of the second half of the twentieth century. Deleuze conceived of philosophy as the production of concepts, and he characterized himself as a “pure metaphysician.” In his magnum opus Difference and Repetition, he tries to develop a metaphysics adequate to contemporary mathematics and science—a metaphysics in which the concept of multiplicity replaces that of substance, event replaces essence and virtuality replaces possibility. Deleuze was also well-known for a number of important monographs he published in the history of philosophy (on Hume, Nietzsche, Kant, Bergson, Spinoza, Foucault, and Leibniz), as well as for his writings on the various arts, which include a two- volume study of the cinema, books on Proust and Sacher-Masoch, a monograph on the painter Francis Bacon, and a collection of essays on literature. Deleuze considered these latter works as pure philosophy, and not criticism, since he sought to create the concepts that correspond to the artistic practices of painters, filmmakers, and writers. In 1968, he met Félix Guattari, a political activist and radical psychoanalyst, with whom he wrote several works, among them the two-volume Capitalism and Schizophrenia, comprised of Anti-Oedipus and A Thousand Plateaus. Their final collaboration was What is Philosophy?.
Deleuze is noteworthy for his rejection of the Heideggerian notion of the “end of metaphysics,” as well as the extent of his non-philosophical references (inter alia, differential calculus, thermodynamics, geology, molecular biology, population genetics, ethology, embryology, anthropology, psychoanalysis, economics, linguistics, and even esoteric thought); his colleague Jean-François Lyotard spoke of him as a “library of Babel.” Although it remains to be seen whether the 20th century will be “Deleuzean,” as his friend Michel Foucault once quipped, Deleuze’s work has already enjoyed a considerable influence both inside and outside the contemporary academy; along with a growing influence in philosophy, Deleuze’s work is approvingly cited by, and his concepts put to use by, researchers in architecture, urban studies, geography, film studies, musicology, anthropology, gender studies, literary studies and other fields.