The Encyclopédie: Diderot's Monument to the Enlightenment

In a Paris bookshop window in June 1751, a heavy two-volume set appeared, with a long title — Encyclopédie, ou dictionnaire raisonné des sciences, des arts et des métiers — and a substantial price. The first volume was a translation, more or less, of an English work; the second was something else entirely. Within a few weeks, the first printing of the first volume had sold out, and a second was underway. Within a few years, the project had become the most ambitious collaborative intellectual undertaking in modern European history and the most thoroughly censored publication in eighteenth-century France. The Encyclopédie would, over the next twenty years, bring together more than a hundred contributors, produce seventeen volumes of text and eleven volumes of plates, change hands among several publishers, survive the suppression of its official publishing privilege, and emerge as the flagship publication of the French Enlightenment. The fact that it was completed at all is a small miracle of editorial stubbornness. The fact that it became the most influential book of the century is a larger one.

The Encyclopédie, published in France between 1751 and 1772, was edited by Denis Diderot and Jean le Rond d’Alembert. It was an attempt to summarize all human knowledge in a single, accessible reference work, and it became a manifesto of the new philosophy of reason, liberty, and progress. The work was repeatedly censored, suppressed, and threatened with destruction, but it was eventually completed, and it became one of the most influential publications of the eighteenth century.

The origins of the project

The Encyclopédie began as a translation project and ended as a comprehensive philosophical and intellectual undertaking. The transformation is one of the great stories of intellectual history, and it is, in a sense, the founding story of the modern encyclopedia.

The translation project

The original project was conceived in the 1740s as a French translation of the Cyclopaedia of the English writer Ephraim Chambers, which had been published in 1728. The French publisher André Le Breton obtained the rights to the translation and assembled a team of editors and contributors. The team included the mathematician Jean le Rond d’Alembert, the physician Louis de Jaucourt, and the philosopher Denis Diderot, who was initially brought in as a minor contributor but who soon became the principal editor of the project.

Diderot transformed the project from a translation into an entirely new work. Rather than simply rendering Chambers’s Cyclopaedia into French, the editors decided to produce a comprehensive new encyclopedia that would summarize all human knowledge and would be organized according to a new philosophical system. The result was a work that was far more ambitious in scope and far more politically engaged than the original translation project had been. The transformation was, in retrospect, the work of a single editorial will — Diderot’s — but it was also the work of the moment. The French reading public in the 1750s was hungry for a comprehensive statement of the new philosophy, and the Encyclopédie was designed, deliberately, to feed that hunger.

The editorial vision

Diderot and d’Alembert’s editorial vision was shaped by the new philosophy of the Enlightenment. The Encyclopédie was to be a comprehensive summary of the state of human knowledge, organized according to a new system that would reflect the structure of the human mind. The work was to be accessible to a wide audience, written in clear and elegant French, and illustrated with extensive plates that would convey the practical arts and the latest scientific discoveries.

The Encyclopédie was also, in effect, a manifesto of the new philosophy. The entries on politics, religion, philosophy, and science were written or commissioned to advance the cause of reason, liberty, and progress. The most radical entries, including those on “Authority,” “Political Authority,” “Ecclesiastical Power,” “Intolerance,” and many other topics, were written by Diderot himself, and they subjected the established institutions of the Old Regime to a systematic critical examination. The cross-references, which Diderot and his collaborators used to connect related topics and to suggest subversive connections, were the most famous editorial innovation. The entry on “Authority,” for example, cross-referenced “Political Authority,” “Ecclesiastical Power,” and “Tyranny”; the entry on “Tyranny” cross-referenced back to “Authority” and to “Despotism.” The reader who followed the cross-references found that the Encyclopédie was a network of subversive connections, rather than a neutral reference work.

The publication of the Encyclopédie

The publication of the Encyclopédie was a long and difficult process, marked by censorship, suppression, and the dedication of the editors and contributors.

The first volumes (1751–1757)

The first volume of the Encyclopédie appeared in 1751, and it was an immediate success. The work was welcomed by the reading public, and it was seen as a major contribution to the new philosophy. D’Alembert’s Preliminary Discourse, which introduced the first volume, provided a sophisticated philosophical analysis of the structure of knowledge, distinguishing among the sciences of nature, mathematics, and the arts. The Preliminary Discourse is, in its own right, one of the most important documents of the French Enlightenment, and it is still read by anyone seriously interested in the eighteenth-century theory of knowledge.

The publication of the second volume in 1752 was also successful, but it provoked a hostile response from the religious authorities. The Sorbonne, the faculty of theology of the University of Paris, condemned several of the articles in the first two volumes, and the government, under pressure from the church, suspended the privilège (the official license to publish) in 1752. The publication was eventually resumed, but the editors and contributors had to be careful in their handling of controversial topics.

The crisis of 1759

The publication of the seventh volume in 1757 was followed by a major crisis. The articles on religion, politics, and philosophy had become increasingly critical of the established order, and the religious and political authorities were growing increasingly alarmed. In 1759, the Council of State revoked the privilège of the Encyclopédie, and the work was officially banned in France.

Diderot and his collaborators refused to give up, however. The publication was continued secretly, with the support of a network of sympathetic publishers and booksellers. The remaining volumes of text appeared between 1760 and 1765, and the eleven volumes of plates were published between 1762 and 1772. The work was never officially reauthorized, but it was widely distributed throughout France and Europe, and it became one of the most influential publications of the century. Robert Darnton’s The Business of Enlightenment (1979) is the standard account of the publishing history, and it shows the remarkable extent to which a banned book, in eighteenth-century France, could be distributed and read.

The completion of the project

The Encyclopédie was finally completed in 1772, with a total of seventeen volumes of text and eleven volumes of plates. The work was about 75,000 pages in length, with about 71,000 articles contributed by about 130 contributors, and it was an enormous intellectual achievement. The Encyclopédie was, by a substantial margin, the largest single publishing project of the eighteenth century, and it was the model for every subsequent attempt to produce a comprehensive statement of the state of human knowledge.

The completion of the Encyclopédie was a major event in the history of the Enlightenment. The work had been censored, suppressed, and threatened with destruction, but it had survived and had become a symbol of the new philosophy. The Encyclopédie was a major force in the development of French intellectual life in the second half of the eighteenth century, and it had an important influence on the development of the French Revolution.

The major contributors

The Encyclopédie was a collaborative work, and its success was due in large part to the dedication of the many contributors who wrote the articles.

Denis Diderot

Denis Diderot (1713–1784) was the principal editor of the Encyclopédie and the most prolific contributor. He wrote or supervised the writing of thousands of articles, including many of the most controversial ones. His articles on politics, religion, and philosophy were a systematic critical examination of the established institutions of the Old Regime, and they were an important part of the intellectual preparation for the French Revolution. Diderot was, in addition to being the principal editor, the philosophical center of the project. He was the one who gave the Encyclopédie its distinctive character — its combination of comprehensive coverage with critical analysis, its commitment to the practical arts alongside the theoretical sciences, and its willingness to push the discussion of controversial topics as far as the censors would allow.

Jean le Rond d’Alembert

Jean le Rond d’Alembert (1717–1783) was the co-editor of the Encyclopédie and the author of the Preliminary Discourse that introduced the first volume. He was one of the leading mathematicians of the eighteenth century, and he contributed many articles on mathematics, science, and philosophy. He withdrew from the Encyclopédie in 1758, partly because of the increasing political pressure and partly because of disagreements with Diderot over the handling of the more controversial articles. The withdrawal was, in retrospect, a serious loss. D’Alembert brought a kind of intellectual seriousness and a respectability that Diderot, with his scandalous personal life and his willingness to push the boundaries of respectable opinion, could not provide. The Encyclopédie after 1758 was a more politically vulnerable work, and the suppression in 1759 was the consequence.

Louis de Jaucourt

The Chevalier de Jaucourt (1704–1779) was the most prolific contributor to the Encyclopédie after Diderot, writing an estimated 8,000 to 17,000 articles (the precise count depends on how attributions are reconstructed). He was a man of vast learning, and he contributed articles on a wide range of topics, including science, philosophy, history, and politics. His articles were generally more moderate than Diderot’s, and he was an important source of the breadth and the comprehensiveness of the Encyclopédie. Jaucourt is, in many ways, the unsung hero of the project. He took over much of the editorial work after d’Alembert’s withdrawal, and he kept the project going through the years of official suppression. The fact that the Encyclopédie was completed was, in significant part, his doing.

Other contributors

The Encyclopédie had about 130 contributors in total, including some of the most important thinkers of the French Enlightenment. The contributors included: Voltaire, who contributed articles on literature, philosophy, and history; Montesquieu, who contributed articles on law, politics, and the history of civilization; the Baron d’Holbach, who contributed articles on chemistry, mineralogy, and philosophy; Jean-Jacques Rousseau, who contributed articles on music and political theory (the article on “Political Economy” is, in particular, a brief statement of his political philosophy); and Toussaint, Venel, and the other scientific contributors, who wrote the articles on chemistry, medicine, and the other natural sciences.

The content of the Encyclopédie

The Encyclopédie was a comprehensive summary of the state of human knowledge, and it covered an enormous range of topics.

The structure of knowledge

The Encyclopédie was organized according to a new system of knowledge that was developed by Diderot and d’Alembert. The Preliminary Discourse of d’Alembert set out the principles of the system, which distinguished among the sciences of nature, the sciences of mathematics, and the sciences of the arts. The system was designed to reflect the structure of the human mind, with the most abstract and most general sciences at the top and the most particular and most practical at the bottom. The system was a substantial contribution to the eighteenth-century theory of knowledge, and it was the model for the modern organization of the disciplines.

The sciences of nature

The Encyclopédie included extensive coverage of the natural sciences, including mathematics, physics, chemistry, biology, and natural history. The articles on the natural sciences were written by some of the leading scientists of the day, and they were an important source of the dissemination of the latest scientific discoveries to a wide audience. The article on “Attraction,” for example, was an accessible account of Newton’s gravitational theory; the article on “Chemistry” was a substantial statement of the new chemistry of Lavoisier and his predecessors.

The sciences of the arts

The Encyclopédie also included extensive coverage of the practical arts, including agriculture, manufacturing, mining, and various other forms of economic activity. The plates of the Encyclopédie were particularly important for the coverage of the practical arts, and they provided detailed illustrations of the various tools, machines, and processes used in contemporary industry. The plates were, in their own right, an important contribution to the history of technology, and they are still used by historians of the eighteenth century as a primary source for the state of the practical arts.

The sciences of the mind

The Encyclopédie included articles on the sciences of the mind, including logic, metaphysics, ethics, and political philosophy. The articles on the sciences of the mind were often the most controversial, and they were the focus of much of the criticism that the Encyclopédie received from the religious and political authorities. The article on “Soul” was a particularly egregious case: the first version was a substantial statement of the materialist position, the second was a more cautious restatement, and the final version — after the suppression of 1759 — was so cautious that it was almost meaningless. The history of the article on “Soul” is a useful index of the editorial compromises that the project required.

The influence of the Encyclopédie

The Encyclopédie had a profound and lasting influence on the development of the Enlightenment and on the subsequent history of modern thought.

The diffusion of the new philosophy

The Encyclopédie was the most important vehicle for the diffusion of the new philosophy. The work was widely read throughout France and Europe, and it was an important factor in the development of the Enlightenment in countries outside France. The translations of the Encyclopédie into other languages — including Italian, German, Russian, and English — helped to spread the new philosophy throughout Europe, and the various adaptations and pirated editions of the work had an even wider influence.

The preparation for the French Revolution

The Encyclopédie was an important part of the intellectual preparation for the French Revolution. The work subjected the established institutions of the Old Regime to a systematic critical examination, and it provided a comprehensive statement of the principles of the new philosophy. The vocabulary of the Revolution — liberty, equality, the rights of man, the sovereignty of the people — was, in important respects, the vocabulary of the Encyclopédie. The connection is most evident in the 1789 Declaration of the Rights of Man, which echoes the language and the structure of the Encyclopédie articles on natural rights and political authority.

The development of modern encyclopedism

The Encyclopédie established the modern model of the encyclopedia as a comprehensive reference work that summarized the state of human knowledge. The various encyclopedias that appeared in the late eighteenth and early nineteenth centuries — the Encyclopaedia Britannica, the Conversations-Lexikon, the Enciclopedia italiana — were all, in important respects, descendants of the Encyclopédie, and they all drew on the model established by Diderot and d’Alembert. The Britannica is the most famous of the successors, and the Conversations-Lexikon (later the Brockhaus) is the most important German-language successor.

The recognition of practical knowledge

The Encyclopédie was an important vehicle for the recognition of practical knowledge. The work treated the practical arts — agriculture, manufacturing, mining — with the same seriousness that it treated the theoretical sciences, and it helped to establish the modern recognition of the value of practical knowledge and of the dignity of those who produce it. The plates of the Encyclopédie were particularly important in this respect. They showed, in detailed illustration, the tools, machines, and processes of the practical arts, and they made the knowledge of the artisan available to the reader of the encyclopedia. The fact that the artisan’s knowledge was worth the attention of the philosopher was, in the eighteenth century, a controversial claim. The fact that it is not controversial now is, in significant part, the legacy of the Encyclopédie.

The legacy of the Encyclopédie

The Encyclopédie remains one of the great achievements of the Enlightenment and one of the great collaborative intellectual projects of modern history. The work was a major force in the development of the French Enlightenment, and it had an important influence on the development of modern thought.

The work remains a basic reference for the study of the history of ideas, and the various modern editions and studies of the Encyclopédie have made it accessible to a wide scholarly and general audience. The Encyclopédie’s commitment to the comprehensive summary of human knowledge, to the accessibility of knowledge to a wide audience, and to the application of reason to the practical problems of human life remains a basic feature of the modern intellectual tradition.

The scholars are still arguing about how to read the Encyclopédie. The traditional reading, associated with the work of Daniel Roche and Daniel Gordon, has emphasized the Encyclopédie as a manifesto of the new philosophy, with the political implications of the articles as the main point. The more recent scholarship, associated with Robert Darnton’s publishing history and with the new attention to the Encyclopédie’s plates, has emphasized the Encyclopédie as a working reference book, with the practical implications of the articles as the main point. The debate is not closed, and it is not going to be closed, because the Encyclopédie is the kind of work that genuinely supports more than one reading.