The Making of the Forbidden Encyclopédie

• Introduction
• Chapter 1 A Translation Gone Awry: The Genesis of the Encyclopédie
• Chapter 2 Denis Diderot and Jean le Rond d'Alembert: The Mind and the Method
• Chapter 3 The Printing Privilege: Navigating Royal Approval
• Chapter 4 Volume One Arrives: Sparks of Enlightenment and Alarm
• Chapter 5 The Jesuit Opposition: The Battle for the French Mind
• Chapter 6 Arrests and Imprisonment: Diderot at Vincennes
• Chapter 7 The Royal Revocation of 1752: The First Great Ban
• Chapter 8 Madame de Pompadour and the Secret Protectors at Court
• Chapter 9 Malesherbes: The Chief Censor Who Saved the Project
• Chapter 10 The Article "Genève" and the Fracturing of the Philosophers
• Chapter 11 The Crisis of 1759: The Parliamentary Condemnation
• Chapter 12 Papal Anathema: Rome Banishes the Encyclopédie
• Chapter 13 Driven Underground: The Decision to Publish in Secret
• Chapter 14 The Ink of Smugglers: Sourcing Paper and Type Across Borders
• Chapter 15 The Secret Presses of Neuchâtel: Switzerland’s Safe Haven
• Chapter 16 Engraving the Invisible: The Massive Task of the Plate Volumes
• Chapter 17 Le Breton’s Betrayal: The Publisher’s Secret Censorship
• Chapter 18 Clandestine Routes: Smuggling Sheets Across European Borders
• Chapter 19 The Subscriptions Network: Funding a Forbidden Empire
• Chapter 20 Police Raids and False Bottoms: Outsmarting the Book Guild Inspectorate
• Chapter 21 The Counterfeiters: Pirated Editions and European Competition
• Chapter 22 Catherine the Great and the Transnational Network
• Chapter 23 The Triumph of 1765: Distributing the Final Text Volumes
• Chapter 24 The Complete Masterpiece: Calculating the Costs of Resistance
• Chapter 25 A World Rewired: How a Banned Book Shaped Modernity

In the mid-eighteenth century, Paris was the undisputed intellectual capital of the Western world, yet it was also a place where a single bound volume could land its authors in a dungeon and send its printer into bankruptcy. To question the divine right of kings, to suggest that religious dogma should submit to reason, or to explain the mechanical arts alongside theology was not merely radical—it was treason. It was into this atmosphere of surveillance and royal absolutism that Denis Diderot and a desperate consortium of Paris booksellers embarked on what was initially meant to be a simple, profitable translation of an English reference work. Instead, their enterprise metastasized into the Encyclopédie—a monumental, twenty-eight-volume masterpiece that dared to reorder all human knowledge and, in doing so, laid the intellectual dynamite that would eventually shatter the Ancien Régime.

The Encyclopédie was the Enlightenment's grandest, most dangerous publishing experiment. Its ambition was intoxicating: to gather the world’s knowledge, subject it to the cold light of reason, and make it accessible to any reader capable of thought. Yet the story of this legendary work is rarely told for what it truly was—a high-stakes, cloak-and-dagger thriller played out across the drawing rooms of Versailles, the damp cells of the Château de Vincennes, the subterranean print shops of Switzerland, and the muddy, smuggler-ridden roads of Western Europe. It was a project constantly teetering on the brink of total destruction, targeted by the Jesuit order, condemned by the Parlement of Paris, and explicitly banned by Pope Clement XIII under pain of excommunication.

The Making of the Forbidden Encyclopédie tells the epic story of how this revolutionary

In the spring of 1728, an English schoolmaster named Ephraim Chambers published a two-volume work in London titled Cyclopaedia: or, An Universal Dictionary of Arts and Sciences. It was a sensible, well-organized compilation designed to give the rising British middle class quick access to useful information on everything from metallurgy to metaphysics. Chambers did not claim to be a original genius; he was a craftsman who possessed the patience to cut up existing treatises, rearrange their contents alphabetically, and link them together with a clever system of cross-references. The book was a commercial triumph. It went through edition after edition, earned its compiler a fellowship in the Royal Society, and proved that there was a lucrative market for reference books that stripped away scholarly jargon and presented knowledge in plain language.

Across the English Channel, Parisian publishers watched the success of the Cyclopaedia with deep envy. In the mid-eighteenth century, the French print trade was tightly controlled, highly conservative, and perpetually hungry for reliable profit. While readers in London enjoyed a relatively free print market, bookmakers in Paris operated under the watchful eye of the Crown, the Church, and the Book Guild. Producing an original work of scholarship was a financial hazard. It required paying authors, enduring months of censorship, and risking royal suppression. Translating a proven foreign bestseller, on the other hand, was standard industry logic. It offered minimum risk for maximum reward.

It was this purely commercial calculation that led André-François Le Breton to the Cyclopaedia. Le Breton was not an intellectual radical, a freethinker, or a literary patron. He was a master printer, the head of a respectable firm located at the sign of the Golden Cross on the Rue Saint-Jacques, and a future senior warden of the Paris Booksellers' Guild. Le Breton was a businessman to his fingertips, cautious, litigious, and immensely protective of his bottom line. In Chambers's two volumes, he saw an easy financial victory. If he could secure a translation of the British work, he could issue it to French readers in a neat, multi-volume set and reap a handsome profit without troubling the authorities or straining his firm's capital.

To execute this routine publishing venture, Le Breton needed a translator who possessed both fluent English and the social standing required to obtain a royal printing privilege. He found his man in John Mills, an Englishman residing in Paris who presented himself as an aristocrat, a gentleman of letters, and an expert in agrarian science. Mills was, in truth, an ambitious adventurer whose financial situation was as precarious as his social claims. To assist with the formidable task of rendering two massive folio volumes into French, Mills enlisted Gottfried Sellius, a German scholar educated at Leyden who had settled in Paris after a checkered academic career across Northern Europe. Sellius was fluent in several languages, chronically short of cash, and willing to write almost anything for a modest fee.

In January 1745, Mills and Sellius entered into a formal agreement with Le Breton. The plan was straightforward: the two scholars would translate Chambers’s text, add supplemental material from other English and continental reference works, and hand the completed manuscript over to Le Breton for printing. To finance the production, the partners decided to open a subscription campaign, inviting the public to pay for the set in advance—a common eighteenth-century technique designed to mitigate the heavy upfront costs of paper, type, and ink.

To legitimize the project, Mills applied for a royal privilege, the exclusive legal right granted by the Crown to print and sell a specific text for a set number of years. On February 26, 1745, King Louis XV granted the privilege for a four-volume translation of the Cyclopaedia. The document was registered in the name of John Mills, an unusual concession for a foreigner that reflected his persuasiveness and Le Breton's early willingness to stay in the background.

With the legal monopoly secured, the partners launched their promotional campaign. In March 1745, they issued a glossy prospectus announcing the upcoming publication of the Dictionnaire universel des arts et des sciences. The prospectus promised prospective buyers four substantial volumes of text and a fifth volume consisting entirely of copperplate engravings. It was touted as a grand improvement upon Chambers, translated by scholars of the highest repute, and offered at an attractive advance rate. Subscriptions began to trickle in, cash entered the firm’s ledger, and for a few weeks, the enterprise looked like a flawless success.

Then the partnership disintegrated into fraud, shouting matches, and street violence.

The first sign of disaster came when Le Breton began examining the actual work produced by his translators. John Mills had vastly overstated his linguistic capabilities and his capacity for hard labor. Rather than providing clear, accurate renderings of Chambers's articles, Mills delivered slow, clumsy, and often incomprehensible drafts. Worse still, Sellius and Mills had begun quarreling over their division of labor and compensation. It soon became apparent to Le Breton that Mills had no intention of keeping to the agreed production schedule, nor did he possess the technical knowledge required to translate specialized entries on mechanics, navigation, or natural philosophy.

As spring turned to summer, the relationship between printer and translator turned toxic. Le Breton discovered that Mills had lied about his financial standing and had used the royal privilege to negotiate side deals. When Le Breton demanded to see completed manuscripts before disbursing further funds, Mills responded with indignation, claiming his honor as an English gentleman had been insulted.

The boiling point was reached on August 7, 1745. Mills arrived at Le Breton’s shop on the Rue Saint-Jacques to demand money. An argument erupted on the premises, escalating quickly from professional insults to personal threats. According to contemporary police records and Le Breton’s subsequent legal depositions, Mills raised his cane and struck the printer. Le Breton, not a man to take a beating in his own establishment, grabbed a heavy walking stick and retaliated, thrashing Mills thoroughly and chasing him out into the street.

The physical brawl marked the end of the original translation scheme, but the legal war had just begun. Mills filed a formal complaint with the Paris police, claiming assault. Le Breton responded by taking immediate action to protect his investment. He petitioned the Crown to revoke the original privilege granted to Mills, arguing that the Englishman had secured it under false pretenses, had failed to perform the contracted work, and had assaulted his French partner.

Le Breton’s standing within the Paris printing establishment carried weight. On December 26, 1745, the Royal Council officially canceled the printing privilege issued in Mills’s name. Outmaneuvered, financially ruined, and facing potential arrest, John Mills fled Paris and returned to England, leaving behind a trail of debt and an abandoned translation. Sellius quietly slipped away to seek other piecemeal literary work, leaving Le Breton in possession of a failed project, a stack of useless translated drafts, and an mounting list of angry subscribers demanding their money back.

Le Breton was now in a difficult position. He held no valid printing privilege, his reputation was damaged, and the commercial viability of the proposed reference work was in grave doubt. Yet he remained convinced that the core idea—a comprehensive, multi-volume dictionary of arts and sciences—was a goldmine if properly executed. The problem was one of scale. The disaster with Mills had demonstrated that a project of this magnitude could not be managed by a single printer operating on limited capital, nor could it rely on a pair of unreliable hack translators.

To salvage the venture, Le Breton decided to spread both the financial risk and the operational burden. He approached three of his most prominent colleagues in the Paris book trade: Antoine-Claude Briasson, Michel-Antoine David, and Laurent Durand.

Each of these men brought distinct assets to the enterprise. Briasson was a wealthy, well-connected publisher operating out of the Rue Saint-Jacques, known for his administrative discipline and extensive distribution connections across Europe. David was an aggressive, shrewd merchant who understood the mechanics of the international trade and possessed a keen eye for marketing. Durand was younger, bolder, and politically adventurous; he had already established a reputation for publishing controversial, edgy literature that skated near the edges of legal tolerance.

On October 18, 1745, the four booksellers signed a formal contract forming a syndicate to produce the dictionary. Under the terms of the agreement, Le Breton retained a fifty percent stake in the venture, while Briasson, David, and Durand divided the remaining fifty percent equally among themselves. They agreed to pool their resources, share production expenses, and publish the work under their joint imprint.

With a powerful syndicate formed, the booksellers successfully applied for a new royal privilege. On January 21, 1746, King Louis XV granted the four publishers an exclusive fifteen-year monopoly to produce an expanded, multi-volume French dictionary of arts and sciences. The new privilege did not merely authorize a direct translation of Chambers; it explicitly permitted the publishers to augment, revise, and expand the text using material from other sources.

The syndicate now possessed legal authority and abundant capital, but they lacked an editor. None of the four booksellers had the time or intellectual capacity to oversee the actual assembly of the text. They needed a respected scholar who could command the respect of the learned world, organize a team of contributors, and bring order to a chaotic mass of material.

In early 1746, they hired Jean-Paul de Gua de Malves.

Gua de Malves was an impressive figure on paper. He was a cleric, an accomplished mathematician, and a member of the prestigious Académie Royale des Sciences. He had published respected works on geometry and was acquainted with many of the leading scientific minds of Paris. To the four publishers, he seemed the ideal editorial director—a man who possessed both academic rigor and the imprimatur of royal scientific approval.

The contract signed with Gua de Malves in June 1746 transformed the project completely. Up to this point, the booksellers had still envisioned a relatively modest adaptation of Chambers's Cyclopaedia, perhaps expanding it from two volumes to four or five. Gua de Malves, however, had far grander ideas. He argued that simply translating an English work published nearly two decades earlier was beneath the dignity of French scholarship. Science, technology, and philosophy had advanced significantly since 1728. The new dictionary, he insisted, must be a completely revised, original work that incorporated the latest discoveries in mathematics, physics, natural history, and the mechanical arts.

The publishers, caught up in Gua de Malves's enthusiasm and seduced by the prospect of a much larger, more expensive set that could be sold for a higher price, agreed to expand the project. They authorized him to recruit specialized scholars to rewrite outdated entries, translate sections from other European encyclopedias, and draft completely original essays.

Among the young, struggling intellectuals Gua de Malves recruited in the spring of 1746 were two men whose names were then virtually unknown to the public: a brilliant, socially awkward mathematician named Jean le Rond d'Alembert, and an impoverished, endlessly energetic man of letters named Denis Diderot.

At thirty-two, Diderot was the quintessential Parisian literary hack. The son of a prosperous cutlery maker from Langres, he had rejected his father’s demands that he pursue a respectable career in law or the Church. Instead, he had spent over a decade living hand-to-mouth in the Latin Quarter, giving private lessons, writing sermons for lazy clergymen, translating English texts for local booksellers, and frequenting the chess tables at the Café de la Régence. He was brilliant, wildly enthusiastic, and perpetually broke.

Diderot had already worked for two members of the publishing syndicate. He had translated Shaftesbury's Inquiry Concerning Virtue and Merit for Durand, and he was currently engaged alongside two other writers in translating Robert James's massive three-volume A Medicinal Dictionary for Briasson. He was known among the publishers as a fast, versatile worker who could master complex subject matter quickly and write with speed and flair.

d'Alembert, by contrast, was a rising star in the formal academic establishment. An abandoned illegitimate child who had been raised by a glazier’s wife in the Rue Michel-le-Comte, his mathematical precocity had propelled him into the Académie des Sciences at the exceptionally young age of twenty-four. Quiet, precise, and intensely devoted to abstract science, d'Alembert brought institutional prestige and intellectual credibility to the enterprise.

Gua de Malves assigned d'Alembert the task of revising and expanding the mathematical and physical articles. Diderot was hired as a translator and general editorial assistant, tasked with handling topics in history, philosophy, and the practical arts.

Yet, despite his grand plans and impressive credentials, Gua de Malves quickly proved to be an administrative disaster. He lacked the basic organizational skills required to manage a large-scale literary enterprise. He was argumentative, arrogant, and chronically incapable of meeting deadlines. Rather than setting up a systematic workflow, he spent months quarreling with the booksellers over his salary, demanding constant financial advances, and alienating the scholars he had hired to assist him.

Gua de Malves’s editorial method was completely chaotic. He lost manuscripts, made conflicting promises to contributors, and proved utterly incapable of managing a budget. By the summer of 1747, over a year after his appointment, virtually no progress had been made toward assembling the first volume. The four booksellers had spent thousands of livres on advances to the editor, fees to contributors, and preliminary advertising, yet they had nothing to show for it except an pile of disorganized notes and a growing mountain of unpaid bills.

The booksellers realized they had traded one incompetent editor for another. John Mills had been an unprincipled scoundrel; Gua de Malves was an impractical academic whose grandiosity threatened to bankrupt the syndicate.

In August 1747, the publishers decided to cut their losses. After a series of heated meetings, Gua de Malves was formally dismissed—or resigned under extreme pressure, depending on whose account one reads. Once again, the project was stalled, its capital drained, its reputation tarnished, and its investors facing financial ruin.

The syndicate stood at a critical crossroads. They had invested two years, obtained a royal privilege, formed a powerful corporate structure, and collected money from subscribers. Abandoning the project meant accepting a catastrophic loss. Yet finding another prominent academician from the Royal Academy of Sciences risked repeating the disaster with Gua de Malves. They did not need another aristocratic scholar with grand pretensions; they needed a working editor who possessed energy, organizational talent, and the desperate hunger of a man who needed to earn his living by his pen.

On October 16, 1747, the four booksellers signed a new agreement that would alter the history of European thought. They abandoned their search for a prestigious figurehead and officially appointed Denis Diderot and Jean le Rond d'Alembert as co-editors of the project.

The contract was signed in Briasson's shop. Diderot was granted a monthly salary of 120 livres, along with a bonus upon completion of the work—a modest sum for a project that would require years of backbreaking labor, but a life-changing income for an impoverished writer who had spent fifteen years in financial uncertainty. d'Alembert was engaged to supervise the mathematical, physical, and scientific entries, while Diderot assumed overall editorial responsibility for the humanities, the history of ideas, and the technical arts.

When Diderot took charge of the project in the autumn of 1747, he inherited a ghost of a book. What had started as a simple, two-volume translation of Ephraim Chambers’s Cyclopaedia was now an administrative wreckage. The translation drafts left behind by Mills and Sellius were largely useless; the notes accumulated by Gua de Malves were fragmentated and incomplete.

Yet Diderot saw in this mess an opportunity that neither Le Breton, nor Mills, nor Gua de Malves had ever imagined. Where others saw a commercial translation or an academic reference book, Diderot envisioned something entirely new. He realized that an alphabetical dictionary possessed a unique, stealthy power. Under the cover of neutral, reference-style entries, one could re-examine every aspect of human knowledge, challenge ancient prejudices, critique established orthodoxies, and systematically promote the methods of empirical science and human reason.

The simple translation had failed. In its place, quietly and without the knowledge of the royal censors who would eventually approve its printing, the real Encyclopédie was about to begin.