“Academics’ lives are seldom interesting,” Gilles Deleuze told Magazine Littéraire in 1988. The life of the mind is not without some amusement: Professors “travel, of course,” the French philosopher continued, “but they travel by hot air, by taking part in things like conferences and discussions, by talking, endlessly talking.” Deleuze was more reclusive than many in the cohort referred to, primarily in Anglo-American circles, as “French theory,” and in spite of considerable evidence to the contrary—25 books published during his lifetime, cited to this day by diverse scholarly blocs—he declined to call himself an intellectual, sincerely or not. Intellectuals, he believed, “have views on everything,” but he had “no stock of views to draw on.” “What I know,” he added, “I know only from something I’m actually working on, and if I come back to something a few years later, I have to learn everything all over again.”

Deleuze defenestrated himself seven years later, at the age of 70, when the respiratory problems that had plagued him since his youth made this work too much to endure. What Is Philosophy?, his final collaboration with the psychiatrist Félix Guattari, was published in English in 1994, the year before he died, and posited an answer to its titular question: “Philosophy is the art of forming, inventing, and fabricating concepts.” Like painting, architecture, music, or cinema, as he wrote in his two-volume study of the last art form, philosophy lays “claim to the new materials and means that the future makes possible.” Deleuze thus summarized a career spent prognosticating the potentials immanent in the subjects he studied: the history of philosophy from Spinoza and Leibniz through Hume, Kant, Nietzsche, Bergson, and his friend Michel Foucault; what he and Guattari called the “minor” literatures of Kafka, Proust, Sacher-Masoch, Lewis Carroll, William S. Burroughs, and others; the theater of Beckett and Artaud, the paintings of Francis Bacon, the music of John Cage, Olivier Messiaen, and Pierre Boulez. He described this methodology as “buggery” or “immaculate conception”: “I saw myself as taking an author from behind and giving him a child that would be his own offspring, yet monstrous.” 

He wasn’t kidding. As the Explain Deleuze meme satirically attests, the author’s writing is known to be painfully difficult, even impenetrable; this is the foremost reason that commentaries on his work now comprise “Deleuze studies,” a distinct if interdisciplinary field. It is to this community alone, perhaps, that the publication of Letters and Other Texts is a highly anticipated release: the third and presumably final volume of outtakes edited by David Lapoujade and published by Semiotext(e), more than a decade after Desert Islands and Other Texts, 1953–1974 and Two Regimes of Madness, 1975–1995. While these earlier editions were among the first to make available English translations of shorter texts that many would consider key to understanding Deleuze’s thought—such as “Intellectuals and Power,” a 1972 interview between Deleuze and Foucault collected in Desert Islands—the pieces compiled in Letters are much less canonical; for that reason, they fascinate as much as they unnerve, leaving the door of the vault open behind them in suggestion that there isn’t much left to find. By collecting these remnants, Letters secures Deleuze’s passage into the realm of a historical figure—like his forebears, an object of study—once and for all, a quarter-century after his death. What the book lacks in the biographical intrigue readers pryingly desire, it makes up for in a scholastic gravitas befitting its subject, further clarifying the development of Deleuze’s corpus if not the intimacies of his personal life.

Deleuze was born in Paris in 1925 to conservative, middle-class parents and grew up in the shadow of his older brother, Georges, who joined the Resistance during the Nazi occupation, for which he was arrested and died en route to a concentration camp. Gilles discovered philosophy in 1943 and the following year enrolled at the Sorbonne, having already established himself in the salons of Marie-Magdeleine Davy, a left-wing Catholic medievalist, and Marcel Moré, a Jules Verne scholar. These gatherings were frequented by such luminaries as Jean-Paul Sartre, Georges Bataille, Pierre Klossowski, Alexandre Kojève, Jean Hyppolite, and Maurice de Gandillac. 

The group was responsible for Germanizing the trajectory of French philosophy, shifting the focal point toward Hegel, Marx, Nietzsche, Freud, and Heidegger, and facilitating the transition from the phenomenology of Bergson and Merleau-Ponty to the structuralism of Claude Lévi-Strauss, Jacques Lacan, Roland Barthes, and Louis Althusser, which the work of Deleuze, Foucault, and Jacques Derrida (all students of Hyppolite and Gandillac) would affirm and then succeed. 

Deleuze’s first publications, included in Letters, ape the style of Sartre most proudly, at times embarrassingly so. The first, “Description of Women,” published in the journal Poésie when Deleuze was 20, presages the concept of “becoming-woman” that he would develop, with Guattari, in A Thousand Plateaus, to the bemusement of some feminists. And not without cause here, either: “The body of the woman is the overwhelming triumph of flesh,” the young Deleuze virginally argues. “The woman is a concrete universal; she is a world, not an externalized world, but under the world, the warm interiority of the world, a compressed internalized world. Whence the prodigious sexual success of women: possessing a woman is possessing the world.”

As Lapoujade notes in the foreword, Deleuze later denounced this juvenilia, “although their publication can no longer be avoided,” as the texts “were being circulated without authorization, and sometimes in a form that contained errors.” Fanny Deleuze, the philosopher’s widow, wrote to Semiotext(e) founder Sylvère Lotringer in advance of Desert Islands’ appearance that her husband left “very specific indications concerning posthumous publications,” but the family’s authorization of Letters seems resigned to the fact that Deleuzians are something like the Deadheads of the theory world: techno-savvy, organized, and obsessively invested in even the scrappiest bootlegs. This is, in part, because many of Deleuze and Guattari’s concepts—“rhizome” among them—were fundamental to early theorizations of the Internet and digital culture, not to mention the thought of former colleagues Alain Badiou and Antonio Negri (whose own co-author, Michael Hardt, was a student of Deleuze) and post-Marxist theorists of science, gender, media, and race from Slavoj Žižek and Jacques Rancière to Isabelle Stengers, Elizabeth Grosz, Fred Moten, and McKenzie Wark. But the incompleteness of the Deleuze archive (he did not keep incoming letters, not counting correspondence as part of his oeuvre) can leave the reader of Letters wanting more, especially given Lapoujade’s hands-off editorial stance, which sends those curious about context to hunt through the stacks.

Deleuze begins his own bibliography, a draft of which is reproduced in Letters, in 1953, after he passed the agrégation in philosophy and published his first monograph, Empiricism and Subjectivity, on the Scottish Enlightenment thinker David Hume. (Notes for two courses on Hume, also published here, emphasize the extent of Deleuze’s specialization and provide readers with a glimpse into his pedagogical style.) Deleuze dedicated the 1950s and ’60s to single-author studies, culminating in two dissertations defended in the wake of May 1968: one on Spinoza, supervised by Ferdinand Alquié (favorable reviews of two of Alquié’s books are included in Letters), and another that would become his most important book written without Guattari, Difference and Repetition, a “philosophy of difference” that inverts Kant’s “transcendental idealism.” This “transcendental empiricism,” Deleuze explained to a correspondent later, “maintains that there is a difference in nature between the empirical and the transcendental…, presupposes that the transcendental is itself experience, experimentation, and finally posits a complete immanence between the two.”

It is here that Deleuze’s work most resembles the deconstruction of Derrida, whose own Writing and Difference and Of Grammatology came out the year before, and the perceived failure of their students to change the world that spring usually serves as the historical signpost that imbued poststructuralism with such promise. The idea that identity is an effect of difference, rather than its cause, allowed this generation of French philosophers to move beyond Marx and Freud and consequently helped empower the evolution of identity politics in the American academy in the 1980s and ’90s, resisting codification and critique by neoliberals from Bernard-Henri Lévy to Camille Paglia simultaneous with its co-option on the right. If our experience of difference actualizes the formation of ideas, Deleuze concluded, then “the concepts of knowledge, morality, religion, etc. can only dissolve” under the scrutiny of critique. Any apparent unity is revealed, in fact, to be the sum of heterogeneous molecules; observed through Deleuze’s microscope, the one becomes many.

Intellectual historians credit Deleuze for inventing a left Nietzscheanism in his second monograph, Nietzsche and Philosophy. When the book was published in 1962, the German philosopher was widely read as a reactionary, not least because of his appropriation by the Nazis, and Deleuze played a prominent role in rehabilitating his reputation in France. (Walter Kaufmann’s Nietzsche: Philosopher, Psychologist, Antichrist and subsequent English translations in the preceding decade performed an analogous function in the United States.) Deleuze characterized Nietzsche as a philosopher of difference, filiating his work to Spinoza (who was Jewish) and interpreting On the Genealogy of Morality as an attempted revision of Kant’s Critique of Pure Reason. This strategy is representative of Deleuze’s method, as he explained in a letter to one of his commentators, Arnaud Villani, in 1986:

I believe a book, if it deserves to exist, can be presented in three quick aspects: you do not write a “worthy” book unless: 1) you think that the books on the same subject or on a neighboring subject fall into a type of overall error (polemical function of the book); 2) you think that something essential has been forgotten in relation to the subject (inventive function); 3) you believe yourself capable of creating a new concept (creative function).

That a writer known for his difficulty was so uncomplicated in his submissions to journals, in his lectures, and in his letters to friends confirms that comprehensibility was not what he was after in the major texts, which are “about” something else altogether.

One of the most valuable inclusions in Letters is an interview that film scholar Raymond Bellour conducted with Deleuze and Guattari in 1973 for Les Temps Modernes, the journal run by Sartre and Simone de Beauvoir, although the interview was never published, because Guattari disapproved of the magazine’s Maoist leanings. It was recorded on the occasion of the publication of Anti-Oedipus, the duo’s first collaboration, which with A Thousand Plateaus constitutes Capitalism and Schizophrenia, a voluminous demonstration of the theoretical practice they call “schizoanalysis,” drawn largely from Guattari’s experience at La Borde, an experimental clinic in the Loire Valley founded by Jean Oury, a student of Lacan, in 1953. Deleuze and Guattari began working on Anti-Oedipus almost immediately after meeting in the spring of 1969, just before Deleuze’s appointment (at Foucault’s recommendation) to the University of Paris VIII, where he would teach until his retirement in 1987. The correspondence through which their cooperation was born is the most substantial of that presented in Letters, and although it is one-sided and not without unfortunate gaps, both the letters and the interview do much to flesh out the details glossed over in the opening sentences of A Thousand Plateaus: “The two of us wrote Anti-Oedipus together. Since each of us was several, there was already quite a crowd.”

While Guattari comes off in the interview as impatient, sarcastic, and brusque, dismissing Bellour’s questions as “lousy” and “stupid,” Deleuze is genial and self-effacing, accepting blame for the “academic aspect” of Anti-Oedipus, which he acknowledges to be a “real bother”; after he returns from a phone call, Guattari says that he told Bellour “the opposite of what you said,” to which Deleuze replies, “Good. Very good.” The same is true of the correspondence, which reveals him to be humble (insisting on the magnitude of Guattari’s contributions), conscientious (attempting to dissuade Villani from writing about his work for the sake of the younger scholar’s career), effusive (in his praise of the Romanian poet Gherasim Luca), and kind (to Klossowski and Foucault, despite eventual fallings-out), even as he commits the venal sins endemic to academic life: to Jean Piel, editor of Critique, he belatedly shirks an assignment on Céline in favor of an article on masochism (reprinted in Letters); in a subsequent letter, he admits, “Instead of limiting myself to the 15 pages we agreed on, I am…sending you 26.”

Mild in disposition, Deleuze was revolutionary in thought, and in the interview with Bellour, his outlook remains forward-thinking, avant-garde, almost punk: “Félix and I, in any case, and a certain number of people, we are not alone, we don’t give a damn.” It would be shortsighted to deduce from this that his ideas bear no influence on the material world, which in its current state, collapsed beneath capitalism’s sickening bloat, could use them more than ever. But to understand concepts like “flux” or “lines of flight” or the “body without organs,” Deleuze insisted, it was not necessary to grasp what they mean; rather, one should read a work like Anti-Oedipus “spontaneously,” like poetry, and ask: Does it pass? “It’s of the same domain as the electrical outlet. A machine that doesn’t work, you need another outlet or another machine. Our book is like that.”

The sense one gets from reading these ephemera is hardly that of a giant resting on his laurels. Instead, we have a portrait of a professional communicator both frustrated and inspired by his inability to communicate. “As soon as there is interpretation, there is shit,” Deleuze told Bellour. Deleuze was no scientist, but in Letters, he cuts the figure of a lab rat, as if to adopt a mantra from Beckett for his own purposes: “Try again. Fail again. Fail better.” Cornel West quoted this bit, from the novella Worstward Ho, live on CNN in reaction to the protests over George Floyd’s murder, citing the insurrectionary power of “the blues line from our Irish brother.” All of which is to say that truth is not to be found in meaning, sense, summary, or translation. It is through creativity, invention, trial, and inevitably error that radical work is done, and Deleuze’s catalog of concepts preserves a lifetime of failures instructive to our moment—not as a bible, but merely one more author to be taken from behind.