Diderot's Encyclopédie Explained: Knowledge, Reason, and the Revolution of Ideas

The Encyclopédie, published in France between 1751 and 1772, was Denis Diderot’s masterwork and the flagship publication of the French Enlightenment. The work 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. This article examines the origins, the content, and the lasting influence of the Encyclopédie.

From Translation to Original Work

The Encyclopédie began as a translation project. In the 1740s, the French publisher André Le Breton obtained the rights to translate the Cyclopaedia of the English writer Ephraim Chambers into French. He assembled a team of editors, including the mathematician Jean le Rond d’Alembert and the philosopher Denis Diderot.

Diderot transformed the project. Rather than simply rendering Chambers’s Cyclopaedia into French, the editors decided to produce a comprehensive new work 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 Encyclopédie was eventually published in seventeen volumes of text and eleven volumes of plates, totaling about 75,000 pages, with about 71,000 articles contributed by about 130 authors. It was the largest publishing project of the eighteenth century, and it became one of the most influential publications of the modern age.

The Editorial Vision

Diderot’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.

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 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 Content

The Encyclopédie covered an enormous range of topics, from the most abstract philosophical questions to the most practical technical matters. The work included articles on philosophy, science, technology, art, music, religion, politics, and many other subjects.

The articles on science and technology were particularly important. The Encyclopédie provided detailed descriptions of the latest scientific discoveries and the most advanced technological processes, and the plates of the Encyclopédie were particularly important for the coverage of the practical arts. The work was an important vehicle for the dissemination of scientific and technical knowledge to a wide audience.

The articles on politics, religion, and philosophy were the most controversial. The Encyclopédie subjected the established institutions of the Old Regime to a systematic critical examination, and the various attempts by the French authorities to suppress the work only confirmed the importance of the principles it was defending.

The Major Contributors

The Encyclopédie was a collaborative project on an unprecedented scale, and its success was due in large part to the dedication of the many contributors who wrote the articles. For the general account of the project, see The Encyclopédie.

Diderot himself 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.

D’Alembert, the co-editor, wrote the Preliminary Discourse and many articles on mathematics, science, and philosophy. He withdrew from the project in 1758, partly because of the increasing political pressure.

Louis de Jaucourt, the most prolific contributor after Diderot, wrote about 18,000 articles on a wide range of topics. He was an important source of the breadth and comprehensiveness of the work.

Other contributors included Voltaire, Montesquieu, Rousseau, the Baron d’Holbach, and many of the other leading figures of the French Enlightenment.

The Suppression of the Encyclopédie

The publication of the Encyclopédie was repeatedly interrupted by the French authorities. The first seven volumes were banned in 1752, and the privilège was withdrawn in 1759. Despite these obstacles, the work was completed and achieved a circulation of about four thousand subscribers, an enormous number for the time.

The suppression of the Encyclopédie was one of the great scandals of the French Enlightenment, and it became a symbol of the struggle of the new philosophy against the established order. The various attempts by the French authorities to suppress the work only confirmed the importance of the principles it was defending, and they helped to create a new public for the ideas of the Enlightenment.

The Legacy

The Encyclopédie had a profound influence on the development of modern thought. The work was the most important vehicle for the diffusion of the new philosophy, and it was an important part of the intellectual preparation for the French Revolution. The various modern encyclopedias that have been developed since the eighteenth century — the Encyclopaedia Britannica, the Conversations-Lexikon, the Enciclopedia italiana — draw on the central arguments of the Encyclopédie.

The basic commitment of the Encyclopédie — 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 commitment of the modern intellectual tradition.