André Le Breton, a bookseller and printer, approached Diderot with a project for the publication of a translation of Ephraim Chambers' Cyclopaedia, or Universal Dictionary of Arts and Sciences into French, first undertaken by the Englishman John Mills, and followed by the German Gottfried Sellius. Diderot accepted the proposal. During this translation his creative mind and astute vision transformed the work. Instead of a mere reproduction of the Cyclopaedia, he persuaded Le Breton to enter upon a new work, which would collect all the active writers, ideas, and knowledge that were moving the cultivated class of the Republic of Letters to its depths but were comparatively ineffectual due to their dispersion. His enthusiasm for the project was transmitted to the publishers; they collected a sufficient capital for a more vast enterprise than they had first planned. Jean le Rond d'Alembert was persuaded to become Diderot's colleague; the requisite permission was procured from the government.
In 1750 an elaborate prospectus announced the project to a delighted public, and in 1751 the first volume was published. This work was very unorthodox and had many forward-thinking ideas for the time. Diderot stated within this work, "An encyclopedia ought to make good the failure to execute such a project hitherto, and should encompass not only the fields already covered by the academies, but each and every branch of human knowledge." Upon encompassing every branch of knowledge this will give, "the power to change men's common way of thinking." This idea was profound and intriguing, as it was one of the first works during the Enlightenment. Diderot wanted to give all people the ability to further their knowledge and, in a sense, allow every person to have any knowledge they sought of the world. The work, implementing not only the expertise of scholars and Academies in their respective fields but that of the common men in their proficiencies in their trades, sought to bring together all knowledge of the time and condense this information for all to use. These people would amalgamate and work under a society to perform such a project. They would work alone to shed societal conformities, and build a multitude of information on a desired subject with varying view points, methods, or philosophies. He emphasized the vast abundance of knowledge held within each subject with intricacies and details to provide the greatest amount of knowledge to be gained from the subject. All people would benefit from these insights into different subjects as a means of betterment; bettering society as a whole and individuals alike.
However, Diderot's work was plagued by controversy from the beginning; the project was suspended by the courts in 1752. Just as the second volume was completed accusations arose, regarding seditious content, concerning the editor's entries on religion and natural law. Diderot was detained and his house was searched for manuscripts for subsequent articles. But the search proved fruitless as no manuscripts could be found. They were hidden in the house of an unlikely confederate–Chretien de Lamoignon Malesherbes, the very official who ordered the search. Although Malesherbes was a staunch absolutist-loyal to the monarchy, he was sympathetic to the literary project. Along with his support, and that of other well-placed influential confederates, the project resumed. Diderot returned to his efforts only to be constantly embroiled in controversy.
These twenty years were to Diderot not merely a time of incessant drudgery, but harassing persecution and desertion of friends. The ecclesiastical party detested the Encyclopédie, in which they saw a rising stronghold for their philosophic enemies. By 1757 they could endure it no longer. The subscribers had grown from 2,000 to 4,000, a measure of the growth of the work in popular influence and power. The Encyclopédie threatened the governing social classes of France (aristocracy) because it took for granted the justice of religious tolerance, freedom of thought, and the value of science and industry. It asserted the doctrine that the main concern of the nation's government ought to be the nation's common people. It was believed that the Encyclopédie was the work of an organized band of conspirators against society, and that the dangerous ideas they held were made truly formidable by their open publication. In 1759, the Encyclopédie was formally suppressed. The decree did not stop the work, which went on, but its difficulties increased by the necessity of being clandestine. Jean le Rond d'Alembert withdrew from the enterprise and other powerful colleagues, including Anne Robert Jacques Turgot, Baron de Laune, declined to contribute further to a book which had acquired a bad reputation.
Diderot was left to finish the task as best he could. He wrote several hundred articles, some very slight, but many of them laborious, comprehensive, and long. He damaged his eyesight correcting proofs and editing the manuscripts of less competent contributors. He spent his days at workshops, mastering manufacturing processes, and his nights writing what he had learned during the day. He was incessantly harassed by threats of police raids. The last copies of the first volume were issued in 1765. At the last moment, when his immense work was drawing to an end, he encountered a crowning mortification: he discovered that the bookseller, fearing the government's displeasure, had struck out from the proof sheets, after they had left Diderot's hands, all passages that he considered too dangerous. The monument to which Diderot had given the labor of twenty long and oppressive years was irreparably mutilated and defaced. It was 12 years, in 1772, before the subscribers received the final 27 folio volumes of the Encyclopédie, ou dictionnaire raisonné des sciences, des arts et des métiers since the first volume had been published.
Read more about this topic: Denis Diderot