Denis Diderot

From New World Encyclopedia

Cover of the Encyclopédie.

Denis Diderot (October 5, 1713 – July 31, 1784) was a French philosopher and writer, a prominent figure in what became known as the Enlightenment, and the editor-in-chief of the famous, Encyclopédie, ou dictionnaire raisonné des sciences, des arts et des métiers. During his career, Diderot moved from Roman Catholicism to deism, atheism, and finally, philosophic materialism. He did not develop a particular system of philosophy, but his original views on a wide variety of subjects influenced many modern thinkers and writers. He promoted the optimistic belief that all knowledge could be acquired through scientific experimentation and the exercise of reason, and championed the value and uniqueness of the individual. He explored the idea that different individuals should be judged by different moral standards according to their circumstances. Diderot also suggested that education should be tailored to the abilities and interests of the individual student, and that students should learn to experiment and do research rather than simply acquiring knowledge.

The Encyclopédie, conceived as a compendium of all available knowledge, challenged the authority of the Roman Catholic Church and of the aristocratic government, both of whom tried to suppress it. The seventeen volumes of print and eleven volumes of engravings were completed in 1772, and remain as a monument of the Enlightenment.

Diderot also contributed to literature by challenging conventions of structure and content with works such as Jacques le fataliste et son maître, Le Neveu de Rameau (Rameau's Nephew), and Règrets sur ma vieille robe de chamber. He announced the principles of a new drama, the serious, domestic, bourgeois drama of real life, in contrast to the stilted conventions of the classic French stage. As an art critic, he favored spontaneity and naturalism, and introduced a theory of ideas expressed by color.


Diderot was born at in Langres, Champagne, France, in 1713, the son of a well-known cutler. Originally intending to become a priest, he studied with the Jesuits at Langres and was tonsured in 1726. He studied in Paris from 1729 to 1732, and received the degree of master of arts at the University of Paris in 1732. He then became an articled clerk in the law offices of Clément de Ris, but continued to pursue the study of languages, literature, philosophy, and mathematics. He abandoned an early ambition to become an actor, and from 1734 to 1744, seems to have made his living by working for a publisher, teaching, and writing sermons for missionaries. He frequently visited the coffee houses, particularly the Procope, where he befriended Jean Jacques Rousseau in 1741. In 1743, he married Antoinette Champion, a linen draper’s daughter, in secrecy because her father did not approve. The couple’s sole surviving child, Angelique, was born in 1753. Diderot educated her carefully, and she later wrote a short biography of her father and classified his manuscripts. Diderot had an affair with the writer Madame Madeleine de Puisieux, whose best work, Les caractères (1750-51), was published during their liaison. He also had an affair with Sophie Volland, from 1755 until her death in 1784, and his letters to her provide a vivid insight into the society of intellectuals such as Louise d'Epinay, F.M. Grimm, the Baron d'Holbach, and Ferdinando Galiani. Among his friends Diderot counted Rousseau (with whom the friendship ended after a quarrel in 1757), Hume, Helvetius, Abbé Raynal, Lawrence Sterne, Marmontel, and Sedaine.

After his marriage, Diderot began to translate English works into French. In 1750, the bookseller André Le Breton approached him about producing a French translation of the Cyclopaedia, or Universal Dictionary of Arts and Sciences of Ephraim Chambers, a Scottish globe-maker. Diderot persuaded Le Breton to expand the project into a collection, written by all the active writers, of all the new ideas and all the new knowledge which was then circulating among the intellectuals of the Republic of Letters. His enthusiasm inspired the publishers, who amassed capital to fund the larger project, and applied for permission from the government. Jean le Rond d'Alembert was persuaded to become Diderot's colleague. Other participants in the enterprise were Voltaire; Chevalier de Jaucourt, a tireless researcher; and Marmontel. In 1750, an elaborate prospectus announced the project to the public, and the first volume appeared in 1751. By 1757, the number of subscribers had grown from 2,000 to 4,000. The last of the letterpress was issued in 1765, but it was 1772 before the subscribers received the final volumes of the Encyclopédie, ou dictionnaire raisonné des sciences, des arts et des métiers. The finished Encyclopédie consisted of seventeen volumes and eleven books of engravings.

For twenty years, Diderot worked incessantly to produce the Encyclopédie, suffering harassing persecution, and the desertion of several of his good friends. The ecclesiastical party detested the Encyclopédie because it gave a voice to materialistic and atheistic philosophers. The French aristocracy felt threatened by the promotion of concepts such as religious tolerance, freedom of thought, and the value of science and industry, and the assertion that the well-being of the common people ought to be the main purpose of a government. A belief arose that the Encyclopédie was the work of an organized band of conspirators against society, whose dangerous ideas were now being openly published. In 1759, the Encyclopédie was formally suppressed by the government, and it became necessary to continue the work clandestinely. The publisher was jailed, then released, and his license was revoked. The threat of visits from the police was a constant harassment, but the censor, de Malesherbes, believed in freedom of the press and warned them of impending raids, so that the manuscripts could be hidden.

D'Alembert withdrew from the enterprise and other powerful colleagues, Anne Robert Jacques Turgot, Baron de Laune, among them, declined to contribute further to a book which had acquired such a bad reputation. Diderot continued to work alone, to complete the Encyclopédie as best he could. He wrote several hundred articles, many of which were laborious and comprehensive. He wore out his eyesight in correcting proofs, and in editing the manuscripts of less competent contributors. He spent his days in industrial workshops, mastering the processes of manufacturing, and his nights in reproducing on paper what he had learned during the day.

At the last moment, when his immense work was complete, Diderot discovered that after he had signed and submitted the final proofs, the publisher, fearing the displeasure of the government, had removed all the passages that he considered too controversial. The manuscript to which Diderot had devoted twenty years was irreparably altered. (A collection of the altered passages was found and published in Russia in 1988.)

The good of the people must be the great purpose of government. By the laws of nature and of reason, the governors are invested with power to that end. And the greatest good of the people is liberty. It is to the state what health is to the individual (from L'Encyclopédie).

While editing the Encyclopédie (1745-1772), Diderot wrote most of his own important works. He never became wealthy from his efforts. In 1765, in order to provide a dowry for his daughter, he put his library up for sale. Catherine II of Russia heard of this and purchased the library, leaving the books in his possession until they were needed and paying Diderot an annual salary to act as librarian and to add to the collection. During 1773 and 1774, Diderot made a difficult journey to Russia to visit Catherine II and help plan the establishment of a Russian university.

Diderot died of emphysema and dropsy in Paris, on July 31, 1784, and was buried in the city's Eglise Saint-Roch. Catherine II deposited his vast library at the Russian National Library.

Thought and works

Diderot was not a coherent and systematic thinker, but rather "a philosopher in whom all the contradictions of the time struggle with one another" (Johann Karl Friedrich Rosenkranz). He was a representative of the intellectual changes that were taking place during the French Enlightenment. During his writing career, Diderot moved from being a devout Roman Catholic to deism and finally to atheism and philosophical materialism. He experienced a reaction to the morality imposed by the Roman Catholic Church, believing that religious dogmas interfered with the natural, organic development of human passions, and contributed many of the most declamatory pages of the Système de la nature, an atheistic work by his friend Paul Henri Thiry, baron d'Holbach. He proclaimed that Christianity was morally harmful for those who believed in it, and a threat to societies which had not yet been introduced to it. Diderot believed that the moral improvement of humanity would directly result in the progress of civilization. He also explored the connection between biology and human culture, and between culture and morality, laying the groundwork for new developments in the social sciences.

Diderot espoused the scientific materialism of the Enlightenment. He had translated some of the writings of John Locke, and agreed with his emphasis on observation and experimentation over abstract speculation. During previous centuries, intellectuals had used empiricism and reason to seek metaphysical truth; during the Enlightenment they sought scientific knowledge of the physical universe. Diderot was confident that all things could be understood by using reason to interpret data supplied through the senses. In one of his earliest philosophical works, Lettre sur les aveugles, he offered an explanation of how phenomena could be accounted for in terms of the motion of matter, and nothing else.

The Enlightenment celebrated the value and uniqueness of the individual; Diderot wholeheartedly embraced this concept in every aspect of his work. He criticized the church for imposing its moral standards on everyone, and the secular education system for assuming that every individual was equally receptive to learning. He theorized that education should develop the curiosity and passionate interests of a student rather than simply instill knowledge. His dramatic works, in contrast to the formal, stilted plays of classic French drama, explored the characters and personalities of individuals and families in ordinary situations of domestic life. He delighted in curious puzzles of right and wrong, and in devising a conflict between the generalities of ethics and the conditions of an ingeniously contrived practical dilemma. Diderot attempted to educate his audience while showing sympathy for his protagonists. One of his best-known works, Le Neveu de Rameau, explores the conflict between a mind of genius and the restrictions of conventional morality. In his writing, Diderot promoted the idea that all human beings had equal value and the right to certain freedoms.

Early works

Diderot's earliest works included a translation of Temple Stanyan's History of Greece (1743); with two colleagues, François-Vincent Toussaint and Marc-Antoine Eidous, he produced a translation of James's Dictionary of Medicine (1746-1748) and about the same date he published a free rendering of Shaftesbury's Inquiry Concerning Virtue and Merit (1745), with some original notes of his own. He composed a volume of erotic stories, Les bijoux indiscrets (1748), which he later regretted publishing. His Pensées philosophiques (1746), a collection of aphorisms (many inspired by Shaftesbury) with a short complementary essay on the sufficiency of natural religion, was burned by the Parliament of Paris for its anti-Christian ideas.

In 1747, he wrote the Promenade du sceptique, an allegory pointing out the extravagances of Catholicism; the vanity of the pleasures of the secular world; and the desperate and unfathomable uncertainty of the philosophy of skepticism, which disdains the values of both the church and the secular world.

Diderot's next piece, Lettre sur les aveugles (1749), introduced him to the world as an original thinker. The immediate object of this short work was to show the dependence of humanity's ideas on their five senses, by considering the case of the intellect deprived of the aid of the sense of sight. The work also suggested a theory of the progression of biological development through a series of stages, which bears some resemblance to the theory of natural selection; and the possibility of teaching the blind to read through the sense of touch. A second piece, the Lettre sur les sourds et muets, considering the case of a similar sense deprivation in the deaf and mute, examined several points of aesthetics. The Lettre sur les aveugles applied the principle of relativism to the concept of God, and was considered so radical that Diderot was seized and thrown into the prison of Vincennes for three months.


The Encyclopédie, ou dictionnaire raisonné des sciences, des arts et des métiers is considered one of the monuments of the Enlightenment. As editor-in-chief, Diderot contributed hundreds of articles, many of them on social and religious philosophy. The Encyclopédie was intended to be a compendium of all theoretical knowledge available to humankind, as well as a practical reference for workmen of all trades. Diderot visited workshops and factories, taking notes on all types of manufacturing practices and eliciting trade secrets, and collaborating with an artist to produce detailed illustrations. As a consequence, the Encyclopédie remains a valuable historical record of the economic practices of the eighteenth century.

The Encyclopédie became a mouthpiece for radical Enlightenment thinkers. It challenged the traditional authority of the Roman Catholic Church and undermined the political establishment by promoting religious tolerance, freedom of thought, and the value of science and industry. Numerous attempts were made to suppress its production, and subscribers were obliged to travel outside of Paris in order to collect the final ten volumes.

Art, drama, and literature

Although the Encyclopédie was Diderot's monumental work, he was the author of new ideas in many areas of intellectual interest. He wrote sentimental plays, Le Fils naturel (1757) and Le Père de famille (1758), accompanying them with essays on dramatic poetry, including the Paradoxe sur le comédien, in which he announced the principles of a new drama, the serious, domestic, bourgeois drama of real life, in opposition to the stilted conventions of the classic French stage.

Diderot was also an art critic. His Essai sur la peinture was described by Johann Wolfgang von Goethe, who thought it worth translating, as a magnificent work, which speaks even more helpfully to the poet than to the painter, though to the painter too it is as a blazing torch." Diderot's most intimate friend, the philologist Friedrich Melchior Grimm, wrote newsletters for aristocrats in Germany, reporting what was going on in the world of art and literature in Paris, then the intellectual capital of Europe. Between 1759 and 1779, Diderot helped Grimm by writing accounts of the annual exhibitions of paintings in the Paris Salon. According to Charles Augustin Sainte-Beuve, these pieces of art criticism initiated a new attitude towards art in France, and introduced people to the mystery and purport of color by ideas. "Before Diderot," Anne Louise Germaine de Staël wrote, "I had never seen anything in pictures except dull and lifeless colors; it was his imagination that gave them relief and life, and it is almost a new sense for which I am indebted to his genius." Diderot's favorite among contemporary artists was Jean-Baptiste Greuze, whose paintings rendered scenes of domestic virtue and the pathos of common life: "It has been said that love robs those who have it of their wit, and gives it to those who have none" (Paradoxe sur le comédien).

Two of Diderot’s most remarkable pieces are Jacques le fataliste (written in 1773, but not published until 1796) and the dialog Le Neveu de Rameau (Rameau's Nephew). Jacques le fataliste et son maître is a humorous, ironic story of fate and individual choice. Diderot wrote the original draft of Le Neveu de Rameau in 1761, and continued to make alterations to it until his death twenty-three years later. Goethe's German translation (1805) was the first publication of Le Neveu de Rameau in Europe; the first French publication did not appear until 1823. Other works include Règrets sur ma vieille robe de chambre (Regrets on Parting with My Old Bathrobe) and Le rêve de D'Alembert, which deals with the constitution of matter and the meaning of life.

Several of Diderot’s books were confiscated because of their radical content, and did not appear in print until after his death, during the French Revolution. La religieuse, the story of a young girl who entered a nunnery and was corrupted by her Superior, was published in 1796. It was originally written by Diderot and Grimm as an attempt to lure their acquaintance, the Marquis de Croismare, to Paris by playing on his interest in the case of a nun who had refused to give up her vows. Diderot sent letters in her name to the marquis, as if she had escaped her convent and was looking for his help, and from these letters he composed the book. Supplement au Voyage de Bougainville, which contains an indictment of slavery and colonialism, was not published until 1796.

Works by Diderot

  • Essai sur le mérite et la vertu, written by Shaftesbury French translation and annotation by Diderot (1745)
  • Pensées philosophiques, essay (1746)
  • La promenade du sceptique (1747)
  • Les bijoux indiscrets, novel (1748)
  • Lettre sur les aveugles à l'usage de ceux qui voient (1749)
  • L'Encyclopédie, (1750-1765)
  • Lettre sur les sourds et muets (1751)
  • Pensées sur l'interprétation de la nature, essay (1751)
  • Le fils naturel (1757)
  • Entretien sur le fils naturel (1757)
  • Salons, critique d'art (1759-1781)
  • La Religieuse, Roman (1760)
  • Le neveu de Rameau, dialogue (1761?)
  • Lettre sur le commerce de la librairie (1763)
  • Mystification ou l’histoire des portraits (1768)
  • Entretien entre D'Alembert et Diderot (1769)
  • Le rêve de D'Alembert, dialogue (1769)
  • Suite de l'entretien entre D'Alembert et Diderot (1769)
  • Paradoxe sur le comédien (c. 1769)
  • Apologie de l'abbé Galiani (1770)
  • Principes philosophiques sur la matière et le mouvement, essay (1770)
  • Entretien d'un père avec ses enfants (1771)
  • Jacques le fataliste et son maître, novel (1771-1778)
  • Supplément au voyage de Bougainville (1772)
  • Histoire philosophique et politique des deux Indes, in collaboration with Raynal (1772-1781)
  • Voyage en Hollande (1773)
  • Eléments de physiologie (1773-1774)
  • Réfutation d'Helvétius (1774)
  • Observations sur le Nakaz (1774)
  • Essai sur les règnes de Claude et de Néron (1778)
  • Lettre apologétique de l'abbé Raynal à Monsieur Grimm (1781)
  • Aux insurgents d'Amérique (1782)
  • Salons

ISBN links support NWE through referral fees

  • Bremner, G. Order and Change: The Pattern of Diderot’s Thought. Cambridge: Cambridge University Press, 1981.
  • Chabut, Marie-helene. Denis Diderot. Rodopi Bv Editions, 1998.
  • Diderot, Denis. Diderot Pictorial Encyclopedia of Trades and Industry, Vol. 1 Dover Publications, 1993.
  • —, David Coward, trans. Jacques the Fatalist. Oxford University Press, 1999.
  • —, John Hope Mason, Robert Wokler, Raymond Geuss, and Quentin Skinner, eds. Diderot: Political Writings. Cambridge University Press, 1992.
  • —, Lorna Sandler, trans. Thoughts on the Interpretation of Nature and Other Philosophical Works. Clinamen Press Ltd., 2000
  • —, Leonard Tancock, trans. Rameau's Nephew and D'Alembert's Dream. Penguin Classics, 1976.
  • This article incorporates text from the Encyclopædia Britannica Eleventh Edition, a publication now in the public domain.

External links

All links retrieved January 29, 2024.

General philosophy sources


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