Andrew Curran | an excerpt adapted from Diderot: The Art of Thinking Freely | Other Press | January 2019 | 19 minutes (5,105 words)

Denis Diderot’s incarceration at Vincennes took place exactly halfway through his seventy years on earth. Prison became the dramatic pause that gave shape and meaning to both sides of his life. Before prison, Diderot had been a journeyman translator, the editor of an unpublished encyclopedia, and a relatively unknown author of clandestine works of heterodoxy; on the day that he walked out of Vincennes, he was forever branded as one of the most dangerous evangelists of freethinking and atheism in the country.

During Diderot’s three-month imprisonment, his jailer the Count d’Argenson and the count’s brother the marquis had looked on with amusement while this “insolent” philosophe had bowed and scraped before the authority of the state. In a diary entry from October 1749, the marquis related with glee how his brother the count had supposedly broken Diderot’s will. Solitary confinement and the prospect of a cold winter had succeeded where the police’s warnings had failed; in the end, the once-cheeky writer had not only begged for forgiveness, but his “weak mind,” “damaged imagination,” and “senseless brilliance” had been subdued. Diderot’s days as a writer of “entertaining but amoral books,” it seemed, were over.

The marquis was only half right. When Diderot was finally released from Vincennes in November 1749, he certainly returned to Paris with his tail between his legs. Entirely silenced, however, he was not. Two years after he left prison, the first volume of the Encyclopédie that he and Jean le Rond d’Alembert were editing together appeared in print. Its extended and self-important title, which indicated a systematic and critical treatment of the era’s knowledge and its trades, promised something far beyond a normal reference work:

Encyclopédie, ou Dictionnaire raisonné des sciences, des arts et des métiers, par une société de gens de lettres. Mis en ordre par M. Diderot, de l’Académie royale des Sciences et des Belles-Lettres de Prusse; et quant à la partie mathématique, par M. D’Alembert, de l’Académie royale de Prusse, et de la Société royale de Londres.

Encyclopédie, or a Systematic Dictionary of the Sciences, Arts, and Crafts, by a Society of Men of Letters. Edited by Mr. Diderot, of the Royal Academy of Sciences and Belles-Lettres of Prussia; and, regarding the mathematical parts, by Mr. D’Alembert, of the Royal Academy of Prussia and the Royal Society of London.

Far more influential and prominent than the short single-authored works that Diderot had produced up to this point in his life, the Encyclopédie was expressly designed to pass on the temptation and method of intellectual freedom to a huge audience in Europe and, to a lesser extent, in faraway lands like Saint Petersburg and Philadelphia. Ultimately carried to term through ruse, obfuscation, and sometimes cooperation with the authorities, the Encyclopédie (and its various translations, republications, and pirated excerpts and editions) is now considered the supreme achievement of the French Enlightenment: a triumph of secularism, freedom of thought, and eighteenth-century commerce. On a personal level, however, Diderot considered this dictionary to be the most thankless chore of his life.


That someone of André-François Le Breton’s stature entrusted the biggest investment of his career to a writer with Diderot’s doubtful reputation may now seem quite odd. Unlike some of the other more daring printers operating in the 1740s — in particular, Le Breton’s partner in the Encyclopédie enterprise, Laurent Durand — Le Breton had carefully avoided controversial publication projects. This was smart business practice. Named one of the six official printers of the king in 1740, Le Breton benefited from a number of privileges, including tax breaks and a steady stream of easy-to-print royal commissions.

Most importantly, however, Le Breton was the designated printer of the Almanach Royal, a calendar that Louis XIV had asked Le Breton’s grandfather, Laurent-Charles Houry, to begin printing in 1683. This extremely profitable reference work, which had swollen to six hundred pages under Le Breton’s editorship, included an impressive range of useful information: astronomical occurrences, saints’ days, religious obligations, and even coach departures (arrivals were less easy to predict). But most of the Almanach was dedicated to a roster of the monarchic, aristocratic, religious, and administrative notables who ruled over twenty-five million Frenchmen. As Louis-Sebastien Mercier put it, Le Breton’s little book anointed the “gods of the earth.” With the exception of the royal printworks located in the Louvre, one would have been hard pressed to find a bookseller or printer more thoroughly associated with the power structure of the ancien régime. Bearing this in mind, when Le Breton brought on d’Alembert and Diderot to the Encyclopédie project, he had no intention of commissioning one of the most provocative works of the century. Some of his lack of concern surely had to do with the genre of the dictionary or encyclopedia itself. While it was true that the Huguenot Pierre Bayle had printed a contentious, four-volume dictionary in 1697 that engaged very critically with Christian dogma and history, he had done so from the relative safety of Holland. The most prominent French Catholic dictionary makers (who were effectively at war with their Protestant counterparts) tended, on the contrary, to corroborate and even strengthen the era’s most traditional ideas on a given subject. If the Encyclopédie’s direct French antecedents — Furetière’s Dictionnaire universel, the Jesuits’ so-called Dictionnaire de Trévoux, and the Dictionnaire de l’Académie française— had been any predictor, Diderot’s and d’Alembert’s Encyclopédie should have been an uncontroversial, although much larger, compendium of knowledge defining the arts and sciences. This, of course, was not the editors’ intention at all; the kind of dictionary that they were envisioning meant completely rethinking the way that dictionaries functioned.

It was the most repressive elements of the ancien régime that spawned the book’s brilliant feints, satire, and irony.

Much of the planning for the third attempt at producing the Encyclopédie took place about a half mile from Le Breton’s print shop, at a Left Bank “eating house” called the Panier fleuri (Flower Basket) on the rue des Grands-Augustins. Well before Diderot began work on the Encyclopédie, he had often come to this teeming quarter near the Pont Neuf — which had several boardinghouses, taverns, and cook-caterers — to meet up with Rousseau. At the time, both men were leading modest, if not marginal, lives. Rousseau had been living in a series of small flats across the river, near the Palais Royal, earning enough money to feed himself by copying music; Diderot, who seemingly moved from apartment to apartment every six months, was also struggling to find his way in Paris. During these days of zealous companionship, the two men even made plans to create a waggish literary magazine called Le Persifleur (The Scoffer). Twenty years later, when Rousseau looked back sentimentally at this happy time in his life, he joked sarcastically that these gatherings must have been the highlight of the week for a man who “always failed to keep his appointments,” because he never “missed a date at the Panier fleuri.”

After Diderot became co-editor of the Encyclopédie in late 1747, d’Alembert too joined these regular meetings at the eatery. Rousseau, who had volunteered to write articles on music for the dictionary, also introduced a soft-chinned priest by the name of abbé Étienne Bonnot de Condillac into the group.

Unlike the three other men who congregated at the Panier fleuri, Condillac would not contribute a single article to the Encyclopédie. And yet, his philosophical orientation and interests had a decisive effect on the theoretical underpinnings of the project. This became particularly true after Condillac shared a manuscript version of his Essai sur l’origine des connaissances humaines (Essay on the Origin of Human Knowledge) with the group in 1746. Building on Locke’s rejection of innate ideas, Condillac put forward a sweeping empiricist understanding of cognition that maintained that our senses are more than the source of the “raw material” for cognition; they also inform the way that our mind works, “teaching” us how to remember, desire, think, judge, and reason. Condillac’s contribution came at a critical point in the project’s prehistory. Though the Catholic priest preferred as a matter of policy to give a wide berth to the Encyclopédie’s heterodoxy, he had nonetheless focused his friends’ gaze on the critical relationship between theories of mind and a proper scientific approach to the study of the exterior world. This would turn out to be one of the foundations of the Encyclopédie project: replacing a theologically compatible theory of cognition with one that had little room for either the soul or an innate awareness of God’s existence.


During these anxious years before the first volume of the Encyclopédie finally appeared, Diderot and d’Alembert spent much of their time poring over the era’s dictionaries and reference works. In addition to identifying the headwords for which they would need to commission articles, the coeditors needed to sketch out what they believed to be the myriad relationships between tens of thousands of possible entries. Thinking through the entire project before delegating their first article, for fear of missing a cross-reference, may have been the most punishing aspect of the Encyclopédie in the early days.

In addition to determining the scope and content of the project, and how exactly to proceed, the coeditors participated in an equally critical venture — attracting subscribers. In the early months of 1750, shortly after his return from Vincennes, Diderot penned a nine-page “Prospectus” in which he announced triumphantly that this book would be far more than a straightforward compendium of the era’s facts and learning; in contrast to earlier dictionaries, the forthcoming Encyclopédie was described as a living, breathing text that would highlight the obvious and obscure relationships between diverse spheres of learning. This was evident in the way that Diderot defined the term “encyclopedia.” Far more than a simple circle or compass of learning — the literal meaning of the Greek enkuklios paideia — this new form of reasoned dictionary would actively examine and restructure the era’s understanding of knowledge.

In their correspondence, Diderot and d’Alembert often described the Encyclopédie project as a theater of war where Enlightenment intellectuals intent on ushering in an era of social change struggled against the constant scrutiny and interference of the French Church and state.

At the same time that Diderot emphasized the project’s innovative qualities, he also let slip several white lies. Such were the conventions of the prospectus genre. The first of these was that the book, which simply did not exist at this point, was nearly completed: “The work that we are announcing is no longer a work to be accomplished. The manuscript and the drawings are complete. We can guarantee that there will be no fewer than eight volumes and six hundred plates, and that the volumes will appear without interruption.”

This bit of creative marketing dovetailed with Diderot’s romantic account of how the Encyclopédie had come into being. In contrast to previous dictionaries or compendiums, he explained, he and d’Alembert had selected an international team of specialists who were experts in their field. The era of the dabbler and the dilettante, he implied, was over:

We realized that to bear a burden as great as the one [d’Alembert and I] had to carry, we needed to share the load; and we immediately looked to a significant number of savants . . . ; we distributed the appropriate piece to each; mathematics to the mathematician; fortifications to the engineer; chemistry to the chemist; ancient and modern history to a man well versed in both; grammar to an author known for the philosophical spirit that reigns in his works; music, maritime subjects, architecture, painting, medicine, natural history, surgery, gardening, the liberal arts, and the principles of the applied arts to men who have proved themselves in these areas; as such each person only [wrote on] what he understood.

To be fair, not all of what Diderot asserts in this 1750 “Prospectus” was untrue. As the project gained momentum, d’Alembert and Diderot convinced more than 150 so-called Encyclopédistes to provide articles. Forty came from the fields of natural history, chemistry, mathematics, and geography; another twenty-two were doctors and surgeons; and twenty-five more were poets, playwrights, philosophers, grammarians, or linguists. Diderot and d’Alembert also commissioned fourteen artists, a group which included engravers, draftsmen, architects, and painters. Some of these specialists ultimately produced large portions of the Encyclopédie. Louis-Jean-Marie Daubenton, the keeper of the king’s natural history cabinet, provided almost one thousand articles on the world’s botanical specimens, minerals, and animal life. The famous Montpellier doctor Gabriel-François Venel illuminated over seven hundred topics, ranging from constipation to the forced evacuation of the stomach. Guillaume Le Blond, a military historian and tutor to the king’s children, wrote some 750 articles, among them dissertations on battlefield strategies, military tribunals, and the various rituals associated with a victory. The renowned legal expert Antoine-Gaspard Boucher d’Argis would ultimately produce four thousand articles ranging from one documenting a plaintiff’s legal recourse after a dog bite to the definition of and punishments for committing sodomy.

And yet, during the first years of Encyclopédie production, Diderot was the motor of the project. Although the title page of the first volume of the work proudly proclaims that the book was being produced by a “Society of Men of Letters” (with eighteen named contributors), he was ultimately obliged to write two thousand articles for this first tome on subjects as varied as geography, childbirth, botany, natural history, mythology, carpentry, gardening, architecture, geography, and literature. He found himself similarly burdened for the second.


While Diderot was furiously writing articles for the first two volumes of the Encyclopédie, d’Alembert was engaged in producing one of the most celebrated texts of the French Enlightenment, the “Discours préliminaire” (“Preliminary Discourse,” 1751). Serving as the primary introduction to the Encyclopédie, this manifesto signaled a dramatic shift in Europe’s cultural and intellectual landscape.

In the first section of the “Discourse,” d’Alembert explains how he and Diderot planned to categorize the tens of thousands of articles that the dictionary would ultimately contain. Implicitly rejecting any a priori categories or authorities, d’Alembert proposes what we might now call a mind-based organization of human knowledge. Beginning with the basic Lockean notion that our ideas arise solely through sensory contact with the exterior world, the mathematician then associates three forms of human cognition with their corresponding branches of learning. Borrowing this idea directly from the English philosopher, statesman, and scientist Francis Bacon and his 1605 Advancement of Learning, d’Alembert asserts that our Memory gives rise to the discipline of History; our Imagination corresponds to the category of Poetry (or artistic creativity); and our ability to Reason relates to the discipline of Philosophy. In addition to creating the three major rubrics under which all the book’s articles would supposedly be organized, this tripartite breakdown established an entirely secular foundation for the web of knowledge presented in the dictionary.

This new interdynamic presentation of knowledge and cross-references…. intentionally and blatantly put contradictory articles into dialogue, thereby underscoring the massive incongruities and fissures that existed within the era’s knowledge.

The second part of the “Discourse” situates the Encyclopédie project within a much larger chronicle of humankind’s scientific and intellectual achievements. After lambasting the medieval era as a millennium of scholarly and scientific darkness, d’Alembert goes on to laud the intellectual heroes of the previous three hundred years, among them Bacon, Leibniz, Descartes, Locke, Newton, Buffon, Fontenelle, and Voltaire. These leading lights, according to the mathematician, had not only combated obscurantism and superstition, but they also gave rise to a new generation of scholars and savants that was now intent on ushering in a more rational and secular era. While d’Alembert’s view of history does not advocate political upheaval by any stretch of the imagination, he was promoting what one might call an Enlightenment version of manifest destiny.

Diderot republished two companion pieces alongside d’Alembert’s “Preliminary Discourse.” The first was the aforementioned “Prospectus,” which not only specifies how the various disciplines would be treated, but provides a useful history of dictionaries. (It is also here that Diderot states, somewhat pessimistically, that, in times of despair or revolution, the Encyclopédie might serve as a “sanctuary” of preserved knowledge, akin to a massive time capsule.) The second document was a large foldout road map for the project, a slightly modified version of the “Système des connaissances humaines” (System of Human Knowledge) that had appeared with the “Prospectus” a year before. Graphically rendering the same breakdown of human understanding that d’Alembert described in the “Preliminary Discourse,” Diderot’s “System” paired Memory with History, Reason with Philosophy, and Imagination with Poetry. And under these cognitively based categories, Diderot spelled out the long list of subjects to be treated.

At first glance, this large map of topics, which ranged from comets to epic poetry, seems quite inoffensive. Indeed, the Encyclopédie’s earliest critic, the Jesuit priest Guillaume-François Berthier, did not quibble with how Diderot had organized the “System”; he simply accused Diderot of stealing this aspect of Bacon’s work without proper acknowledgment. Diderot’s real transgression, however, was not following the English philosopher more closely. For, while it was true that Diderot freely borrowed the overall structure of his tree of knowledge from Bacon, he had actually made two significant changes to the Englishman’s conception of human understanding. First, he had broken down and subverted the traditional hierarchical relationship between liberal arts (painting, architecture, and sculpture) and “mechanical arts” or trades (i.e., manual labor). Second, and more subversively, he had shifted the category of religion squarely under humankind’s ability to reason. Whereas Bacon had carefully and sagely preserved a second and separate level of knowledge for theology outside the purview of the three human faculties, Diderot made religion subservient to philosophy, essentially giving his readers the authority to critique the divine.


In their correspondence, Diderot and d’Alembert often described the Encyclopédie project as a theater of war where Enlightenment intellectuals intent on ushering in an era of social change struggled against the constant scrutiny and interference of the French Church and state. The result, from d’Alembert’s point of view, was a book that suffered from a fundamental inability to say precisely what it needed to say, especially in matters having to do with religion. Diderot was even more categorical. As he finally completed work on the last volume, he blamed the radically uneven quality of the articles on the unending compromises he was obliged to make to satisfy the censors. And yet one of the many ironies associated with the Encyclopédie is that the same conservative constituencies that succeeded in censoring and shutting down the publication of the Encyclopédie on two occasions were partially responsible for the genius and texture of this huge dictionary. After all, it was the most repressive elements of the ancien régime that spawned the book’s brilliant feints, satire, and irony, not to mention its overall methodological apparatus and structure.

Diderot reminds his readers that the more extraordinary an asserted ‘fact’ may be, the more one must seek out witnesses to confirm it.

Even the most noncontroversial and seemingly benign aspect of the Encyclopédie — its alphabetical order — was chosen with this in mind. By organizing the book’s 74,000 articles alphabetically (as opposed to thematically), d’Alembert and Diderot implicitly rejected the long-standing separation of monarchic, aristocratic, and religious values from those associated with bourgeois culture and the country’s trades. In their Encyclopédie, they decided, an article on the most sacred subject of Catholicism could find itself next to an involved discussion of how brass was made. Furthermore, the arbitrary nature of alphabetical order authorized them to “orient” their reader as they saw fit, through a highly developed and subtle system of linking and cross-references.

Through the power of the digital humanities, we now know much more than Diderot himself ever did about the network of cross-references or renvois that he and d’Alembert sprinkled throughout the Encyclopédie. In all, approximately 23,000 articles, or about one-third, had at least one cross-reference. The total number of links — some articles had five or six— reached almost 62,000. Early on, Diderot and d’Alembert were quite coy about the function of their cross-references in both the “Preliminary Discourse” and the “Prospectus.” But by the time that Diderot wrote his famous self-referential article on the project — the entry for “Encyclopédie” that appeared in the fifth volume in November 1755 — he had allowed himself to be more forthright about how this system of cross-references functioned.

The Encyclopédie, Diderot explains, contains two kinds of renvois: material and verbal. The material references are akin to contemporary hyperlinks: discipline-or subject-based recommendations for further study that “indicate the subject’s closest connections to others immediately related to it, and its distant connections with others that might have seemed remote from it.” Designed to produce a dynamic relationship between and among subjects, the material renvoi echoes the vibrant and forceful way that Diderot himself tended to think. As he put it, “at any time, Grammar can refer [us] to Dialectics; Dialectics to Metaphysics; Metaphysics to Theology; Theology to Jurisprudence; Jurisprudence to History; History to Geography and Chronology; Chronology to Astronomy; Astronomy to Geometry; Geometry to Algebra, and Algebra to Arithmetic, etc.” Earlier dictionaries, with the exception, once again, of Bayle’s Dictionnaire historique et critique (Historical and Critical Dictionary), generally sought to communicate a linear and singular vision of truth. This new interdynamic presentation of knowledge and cross-references had a different function: it not only highlighted unobserved relationships among various disciplines, but intentionally and blatantly put contradictory articles into dialogue, thereby underscoring the massive incongruities and fissures that existed within the era’s knowledge. Readers who followed d’Alembert and Diderot on this intellectual journey could not help but question a number of the era’s traditional convictions related to religion, morality, and politics.

In addition to these potentially thought-provoking cross-references, the Encyclopédie’s articles were interspersed with what Diderot called “verbal” links that guilefully satirized some of the era’s sacred cows, or “national prejudices.” He writes: “Whenever [an absurd preconception] commands respect, [the corresponding] article ought to treat it respectfully, and with a retinue of plausibility and persuasion; but at the same time, this same article should also dispel such rubbish and muck, by referring to articles in which more solid principles form a basis for contrary truths.”

Some of these satirical renvois functioned quite bluntly. The article on “Freedom of Thought,” for example, pointed to Diderot’s biting entry on ecclesiastical “Intolerance,” inviting its reader to cultivate a critical viewpoint. Other references were more playful, including the renvoi that Diderot embedded in the article “Cordeliers” or “Franciscans.” This humorless entry begins with the history of the religious order before arriving at an in-depth description of the Cordeliers’ vestments, particularly their hoods; it then concludes by praising the religious order for its sobriety, piety, morals, and the great men it has produced in the service of God. The cross-reference, however, sends the reader to the article “Hood,” a comical entry where Diderot explains that a number of religious orders, including the Cordeliers, have hotly debated the type and shape of hood that their order should wear. This “fact” is followed by a fabricated story detailing how a century-long war broke out between the two factions of the Cordelier sect: “The first [faction of Cordeliers] wanted a narrow hood, the others wanted it wider. The dispute lasted for more than a century with much intensity and animosity, and was just barely put to an end by the papal bulls of four popes.”

As satire goes, the linking of “Cordeliers” and “Hood” — which drew an implicit comparison between this ridiculous anecdote and the far more serious and insoluble debate between Jansenists and Jesuits — was comparatively mild. Less so were some of the other subject couplings that Diderot did not mention in his article “Encyclopédie.” The most famous example is the entry on “Anthropophages” or “Cannibals”: its cross-references directed readers to the entries for “Altar,” “Communion,” and “Eucharist.”

No man has received from nature the right to command other men.

The possibility of finding such scandalous satire incited the Encyclopédie’s audience to read the book more comprehensively than one did a typical dictionary. Yet Diderot and d’Alembert were very careful not to insert such patently irreligious ideas in the most obvious places. Indeed, for potentially touchy subjects such as “Adam,” “Atheist,” “Angels,” “Baptism,” “Christ,” “Deists,” and “Testament,” the editors tended to commission orthodox articles. For the most incendiary topics, including materialism, Diderot decided to forgo commissioning or writing an article altogether.

Yet Diderot and d’Alembert certainly amused themselves by sprinkling the dictionary with irreligious notions, often within the most arcane of articles. Consider, for example, Diderot’s treatment of the Central Asian “Vegetable Lamb Plant” (“Agnus scythicus”). Commenting on claims that this massive flower supposedly produces a goatlike animal with head and hooves on its tall central stem, Diderot reminds his readers that the more extraordinary an asserted “fact” may be, the more one must seek out witnesses to confirm it. Few readers would have misunderstood what Diderot was talking about when he concluded that all such miracles, which always seem to be witnessed by only a few people, “hardly deserve to be believed.”

Diderot and d’Alembert also encouraged another form of satire, commissioning articles whose stodgy and earnest conformism provided their own form of mockery. Such was the case for abbé Mallet’s plodding, five-thousand-word assessment of “Noah’s Ark,” a creationist account of the world that enters into absurdly laborious detail about the amount of wood used for the great ship, the number of animals saved (and those to be slaughtered for meat), and the system of manure disposal needed for the thousands of creatures aboard. Whether Mallet realized it or not, his explications of traditional Church doctrine not only bog down under the weight of their own improbable and contradictory assertions, but raise far more questions than they resolve.

Not all articles employed such oblique irony. Sometime in 1750, Diderot wrote a provocative entry on the subject of the human âme (soul) that he appended to a much longer article on the same subject, written by the Christian philosopher abbé Claude Yvon. Yvon’s article, which Diderot himself had commissioned, gives a massive, 17,000-word history of the concept of the soul that includes frequent attacks against Spinoza, Hobbes, and the threat of materialism. From Yvon’s Cartesian point of view, the soul is linked to God and, like the deity, is immaterial and immortal; and only humans, as opposed to animals, are blessed with this incorporeal essence. One suspects that, against his better judgment, Diderot simply could not let this lengthy dissertation stand without some sort of rebuttal.

In his supplementary article, which the Jesuits attacked immediately upon its publication, Diderot did not get bogged down in abstruse theological questions. Instead, he asked a far simpler question: if the immaterial soul is supposedly the seat of consciousness and emotion, where does it connect to the body? In the pineal gland, as Descartes had asserted? In the brain? In the nerves? The heart? The blood? Drawing attention to theology’s inability to answer this question, he then went on to demonstrate that the supposed immateriality of consciousness — and the soul — was more tied to the physical world than many people believed. If someone is delivered poorly at birth by a midwife, has a stroke, or is hit violently on the head, says Diderot, “bid adieu to one’s judgment and reason” and “say goodbye” to the supposed transcendence of the soul. Diderot’s critics understood perfectly well what the philosophe was saying in this article: the true location of the soul is in the imagination.

The only other subject more problematic than religion was politics. In a country without political parties, where sedition was punished by sentencing to a galley ship or death, d’Alembert and Diderot never overtly questioned the spiritual and political authority of the monarchy. Yet the Encyclopédie nonetheless succeeded in advancing liberal principles, including freedom of thought and a more rational exercise of political power. As tepid as some of these writings may seem when compared with the political discourse of the Revolutionary era, the Encyclopédie played a significant role in destabilizing the key assumptions of Absolutism.

Diderot’s most direct and dangerous entry in this vein was his unsigned article on “Political Authority” (“Autorité politique”), which also appeared in the first volume of the Encyclopédie. Readers who chanced upon this article immediately noticed that it does not begin with a definition of political authority itself; instead, it opens powerfully with an unblemished assertion that neither God nor nature has given any one person the indisputable authority to reign.

political authority: No man has received from nature the right to command other men. Freedom is a gift from the heavens, and each individual of the same species has the right to enjoy it as soon as he is able to reason.

Autorité politique” did more than simply challenge the idea that a monarch derives his political legitimacy from the will of God. Anticipating what Rousseau would write several years later in the much more famous Discourse on Inequality (1755), Diderot goes on to recount the origins of political power and social inequality as arising from one of two possible sources, either “the force or violence” of the person who absconded with people’s freedom, which was Hobbes’s view, or the consent of the subjugated group through established contract, which came from Locke. While Diderot does not contradict the right of the French kings to rule directly — he later goes on to praise Louis XV — he also puts forward the perilous idea that the real origin of political authority stems from the people, and that this political body not only has the inalienable right to delegate this power, but to take it back as well. Forty years later, during the Revolution, the most incendiary elements of “Autorité politique” would provide the skeleton for the thirty-fifth and last article of the 1793 Declaration of the Rights of Man and of the Citizen, which asserted not only the sovereignty of the people, but the right to resist oppression and the duty to revolt.

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Andrew S. Curran is the William Armstrong Professor of the Humanities at Wesleyan University. The author of two previous books, Sublime Disorder: Physical Monstrosity in Diderot’s Universe and The Anatomy of Blackness: Science and Slavery in an Age of Enlightenment, Curran is a Fellow in the history of medicine at the New York Academy of Medicine and a Chevalier dans l’Ordre des Palmes Académiques.

Excerpted from Diderot and the Art of Thinking Freely, by Andrew S. Curran, published by Other Press on January 15, 2019. Copyright © Andrew S. Curran. Reprinted by permission of Other Press.

Longreads Editor: Dana Snitzky