Denis Diderot


Denis Diderot († July 31, 1784 in Paris) was a French abbe, writer, translator, philosopher, Enlightenment philosopher, literary and artistic theorist, art agent for the Russian Tsarina Catherine II, and one of the principal organizers and authors of the Encyclopédie.

Together with Jean-Baptiste le Rond d”Alembert, Diderot, who had an outstanding universal, according to Voltaire “pantophilic” knowledge, was the editor of the great French Encyclopédie, to which he himself contributed as an encyclopedist about 6000 of a total of 72,000 articles. As an author of stage works and theatrical aesthetic writings, he played a major role in the emergence of a bourgeois drama. His novels and stories – most of them, like La religieuse, Jacques le fataliste, or Le Neveu de Rameau, published posthumously – contributed in various ways to the major themes of the European Enlightenment period, including the issues of human self-determination, the body-soul problem, and the opposition between determinism and free will, as well as the critique of religion.

In his works, a clear development from a theistic to a deistic to an atheistic attitude is recognizable. But there are also indications that his materialistic and atheistic ideas were already present in his early works, for example in the Pensées philosophiques (1746) Diderot”s philosophical thoughts, which almost always refer to the experience of individual sensations or perceptions, can be placed in the category of sensualism.

In his later works, Diderot advocated the popularization of the Enlightenment, of atheism, and against what he saw as the still too widespread phenomena of superstition and bigotry. In their works, Diderot and his comrades-in-arms, the philosophes, no longer left religious institutions and various agencies with sole interpretive authority over the world and the sciences. Thus, there was less room for belief in supernatural and irrational forces in Europe, which was under Enlightenment influence, and in North and South America, which was influenced by it.

At the center of Diderot”s thinking was the tension between reason and sensibility (sens et sensibilité) that was typical for his time. For Diderot, reason was characterized by the search for scientifically founded knowledge and the verifiability of empirically observed and proven facts, without remaining caught up in the purely quantitative recording of reality, in mathematical statements. In the years 1754 to 1765, he also developed the doctrine of a universal sensibility (sensibilité universelle).

According to Diderot, the natural sciences were characterized by the fact that they do not ask why, but seek an answer to the question of how. He dealt with many fields of knowledge, including chemistry, physics, mathematics, but above all natural history as well as anatomy and medicine. As a philosophical position he developed – as can be seen in his later works – an (undogmatic) materialistic attitude of mind. Although Diderot was not a philosopher who dealt with “justification-theoretical” problems or systematizing, analytical reflections, he counts among the most diverse and innovative philosophical authors of the 18th century.

Diderot and his companions repeatedly found themselves confronted with the ruling ideas of the Ancien Régime through their Enlightenment reflections and publications, and were therefore subjected to numerous repressions. His imprisonment in 1749 made Diderot wary of further controls and surveillance by the various agencies, although he and the encyclopedists were secretly assisted by some people from the circle of the influential and ruling – including Mme de Pompadour, Louis XV”s mistress, and also some ministers and, above all, the chief censor Chrétien-Guillaume de Lamoignon de Malesherbes. Nevertheless, Diderot”s interested contemporaries, who knew him exclusively through his publications, had access only to a limited selection of essays, novels, dramas, but probably to all his contributions to the Encyclopédie.

Diderot”s personal intellectual and literary emancipation took place against the background of a general change in the economy and society of the Ancien Régime in the wake of the Grand Siècle: Around the year 1700, the French economic system was still almost entirely stuck in the subsistence stage. Thus, almost all production served to meet immediate subsistence needs, and only a relatively small proportion of total output was produced as a surplus for the market. The most important sector was still agriculture, which generated comparatively low yields due to traditional, low-tech farming methods on mostly smallholdings and was heavily dependent on cyclical production crises.

Crafts remained without significant quantitative or qualitative changes during the late Ancien Régime. Manufactories developed hesitantly in 18th century France. At least the guild barriers were relaxed at the beginning of 1770. However, Anne Robert Jacques Turgot, who as contrôleur général des finances between 1774 and 1776 sought to abolish the guilds (corporations) altogether in order to reform craft production in the sense of mercantilist economic promotion, was unable to push through his plan. At the same time, the French bourgeoisie, especially in the metropolises such as Paris, Bordeaux and Marseille, received strong impetus from an increase in foreign trade outside Europe. There was a shift in emphasis from Mediterranean to Atlantic trade. Colonial territories were thus integrated into the European economic system. A prerequisite for the development of these long-distance trade relations and especially maritime trade was the rapid availability of capital through uncomplicated payment procedures involving bank loans. Profiteers of this development were the merchants and trading companies (French East India Company and French West India Company, respectively) in the trading metropolises on the coasts.

The opinion-forming influence of the high aristocratic court culture and its institutions diminished to the extent that this bourgeoisie gained in contours. The multitude of publications (newspapers, intellectual journals) and the simultaneous increase in literacy, as well as the salons and cafés, increasingly determined intellectual life. In these places, the nobility and the bourgeoisie met in a discursive process. The discussions clarified their own positions, they helped to change values and motives, attitudes and views of an ideological-religious as well as scientific-technical nature and to make these changes public.

The emerging bourgeoisie and the complex changes in the economic and social situation for large sections of French society increasingly called the existing political system of the ancien régime into question. In his 1751 encyclopedia article on political authority (Autorité politique), Diderot rejected the divine right to authority as well as the natural law derivation of monarchical authority.

With regard to his political ideas, even after his return from Russia in 1774, Diderot still placed certain hopes in enlightened absolutism, that is, in the idea of a monarchy in which the intellectual elites would help to introduce ideas of the Enlightenment from the “top down,” so to speak. He essentially abandoned these hopes in the years 1770 to 1774.

Youthful years in Langres (1713 to 1729)

Diderot was the second eldest child of Didier Diderot, a wealthy Jansenist master cutler from Langres (then the capital of the bishopric of Langres, now Haute-Marne) and his wife Angélique Vigneron (October 12, 1677 – October 1, 1748), the thirteenth daughter of a tanner. His grandfather Denis Diderot (1654-1726) had married Nicole Beligné (1655-1692), the daughter of a master cutler François Beligné (1625-1697) and his wife Catherine Grassot, on June 20, 1679. The couple had a total of nine children, among them Denis Diderot”s father, the master craftsman (maître de guilde) Didier Diderot.

Denis Diderot was born on Thursday, October 5, 1713, and baptized the very next day in the Église paroissiale Saint-Pierre-Saint-Paul in Langres according to the Roman Catholic rite. Diderot had five younger siblings, two of whom died in infancy. With his sister Denise Diderot (1715-1797) he had a very good relationship throughout his life, he called her Sœurette. With his younger brother Didier-Pierre Diderot (1722-1787), a later clergyman and canon of Langres, his relationship was conflictual. Another sister, Angélique Diderot (1720-1749), joined the Ursuline Order.

Denis Diderot was born in a house in the center of Langres, n° 9 de la place dans le center ville de Langres. The square today bears his name.

From the age of twelve, his parents prepared him for the priesthood. On August 22, 1726, he received tonsure from the Bishop of Langres, Pierre de Pardaillan de Gondrin (from 1724 to 1733), and with it the lower orders. He now had the right to call himself an abbé and to wear clerical garb. In the near future he was to take over the canonical prebend of his maternal uncle, Canon Charles Vigneron at the Cathédrale Saint-Mammès de Langres. Langres, an important center of Jansenism in the 18th century, had about 8000 inhabitants at that time.

In Langres, Diderot attended a Jesuit school, collège des Jésuites.

The Parisian beginnings (1729 to 1743)

At the age of 16, Diderot planned to go to Paris on his own. His father, however, thwarted this plan and personally brought his son to Paris, where he had acquired a place for him to study. Thus, Diderot was first admitted to the Lycée Louis-le-Grand in Paris, then transferred to the Jansenist-oriented Collège d”Harcourt. He finished the propaedeutic college studies on September 2, 1732, with the degree of Magister Artium (maître-des-arts de l”Université). He omitted to follow the planned study of theology, but completed his studies at the Sorbonne on August 6, 1735, as a bachelor.

From 1736, Diderot worked as a paralegal for Louis Nicolas Clément de Ris, avocat au Parlement de Paris, who was also from Langres. When he left this position in 1737, his father ended the regular monetary allowances. Diderot now lived for four years on literary assignments, writing sermons for clergymen and working as a tutor for a wealthy financier, learning English along the way. To a certain extent, the young Diderot led the life of a bohemian. It was a time of chronic shortage of money. At times he was helped by the Carmelite Friar Angelus or his mother, who even sent her maid Hélène Brûlé on foot to Paris to support him financially. Also a Monsieur Foucou from Langres, a friend of his father, who – originally also a cutler – worked as an artist and dentist in Paris, is said to have frequently helped Diderot with money. That same Foucou later helped write the encyclopedic entry on “steel.”

Diderot was enthusiastic about the theater, but was also strongly interested in mathematics. He met the mathematician and philosopher Pierre Le Guay de Prémontval and attended his lectures in 1738, as well as those of Louis-Jacques Goussier. Other acquaintances from this time were the literary figure Louis-Charles Fougeret de Monbron, the later Cardinal François-Joachim de Pierre de Bernis, and the later Prefect of Police of Paris Antoine de Sartine.

Beginning in 1740, Diderot wrote articles for the Mercure de France and the Observations sur les écrits modernes. During this time, he also attended anatomy and medicine lectures with César Verdier.

In 1740, Diderot first lived in a house on Rue de l”Observance (now Rue Antoine-Dubois) in what is now the 6th arrondissement, not far from the École de médecine, one floor below the German engraver Johann Georg Wille. Wille described him as a “very affable young man” who “wanted to be a good writer and, if possible, an even better philosopher.” That same year, he moved several times, to Rue du Vieux-Colombier, also in the 6th, and to Rue des Deux-Ponts in what is now the 4th arrondissement.

Later, Diderot took over translating activities from English into French. He learned English by means of a Latin-English dictionary. In 1742 he translated the Grecian History (“History of Greece”) by Temple Stanyan. Robert James had written the three-volume English dictionary A medicinal dictionary, including physics, surgery, anatomy, chemistry and botany (1743-1745) in the early 1740s. The French physician Julien Busson revised and expanded it into a six-volume work, Dictionnaire universel de médicine, which was translated into French between 1746 and 1748 by Diderot, François-Vincent Toussaint, and Marc-Antoine Eidous and proofread by Busson.

Diderot also translated Shaftesbury”s Inquiry concerning Virtue (Essai sur le mérite et la vertu) in 1745. Shaftesbury”s ideas strongly influenced the French Enlightenment. For Diderot, the aversion to dogmatic thinking, tolerance, and morality based on humanistic ideals were particularly important. With great interest Diderot also read the Essais of Michel de Montaigne.

During these years, Diderot befriended other young intellectuals, such as D”Alembert, Abbé Étienne Bonnot de Condillac, and Melchior Grimm. He frequented the Café de la Régence and the Café Maugis, which was also frequented by Jean-Jacques Rousseau; Diderot met him in July 1742. Rousseau, Condillac, and Diderot met at times once a week at a restaurant near the Palais Royal, the Hôtel du Panier Fleuri.

Marriage and family from 1743

Anne-Antoinette Champion, called Nanette, lived with her mother in 1741 in the Rue Boutebrie, where the two women lived from white sewing and lace-making. Diderot lived in a small room of the same house at this time. In 1743, when he wanted to marry the propertyless, dowry-less, professed Catholic Nanette and, as was customary, asked his father for permission, the latter, by virtue of his paternal authority, had him confined to a Carmelite convent near Troyes. Diderot”s antipathy to the church and the institution of the convent is probably rooted in this experience – an antipathy that later increased when his youngest sister voluntarily entered the convent and became mentally ill there. Diderot was able to escape after a few weeks, he returned to Paris and secretly married Anne-Antoinette Champion on November 6, 1743. Anne-Antoinette”s relationship with her father-in-law later normalized, by 1752 at the latest it was a friendly one.

The family first lived in Rue Saint-Victor in what is now the 5th arrondissement, in 1746 they moved to Rue Traversière, and in April of the same year they moved on to n° 6 Rue Mouffetard, also in the 5th arrondissement. The police officer François-Jacques Guillotte, who became a friend of Diderot, lived nearby. From 1747, the Diderot family lived at n° 3 Rue de l”Estrapade, then from 1754 to 1784 on the fourth and fifth floors of a house on Rue Taranne, now at 7th and 6th arrondissements.

In his essay Regrets sur ma vieille robe de chambre ou Avis à ceux qui ont plus de goût que de fortune (1772), Diderot described his fourth-floor study. A chair made of woven straw, a simple wooden table and book boards made of fir wood, on the walls simple Italian color wallpaper, in addition frameless copper engravings, some alabaster busts of Horace, Virgil and Homer. The table was covered with printed sheets and papers. On the fifth floor, under the attic, he had set up the editorial office of the Encyclopédie.At a friend, the jeweler Étienne-Benjamin Belle, in Sèvres, n° 26 Rue Troyon, Diderot rented an additional apartment around October or November 1767. There he regularly retired to work until shortly before his death. His last residence, where he also spent the last days of his life, was located at n° 39 Rue de Richelieu in what is now the 2nd arrondissement of Paris.

The couple had four children, three of whom died very young, Angélique (1744-1744), Jacques François Denis (1746-1750), Denis-Laurant (1750-1750), and Marie-Angélique (September 2, 1753 – December 5, 1824). Marie-Angélique married the industrialist Abel François Nicolas Caroillon de Vandeul on September 9, 1772. He was the son of Diderot”s childhood sweetheart Simone la Salette (1713-1788) and her husband Nicolas Caroillon (1708-1766).

Diderot had two grandsons, Marie Anne (1773-1784), who died at an early age, and Denis-Simon Caroillon de Vandeul (1775-1850), who became a politician. Diderot”s three great-grandchildren, Abel François Caroillon de Vandeul (1812-1870), Marie Anne Wilhelmine Caroillon de Vandeul (1813-1900) and Louis Alfred Caroillon de Vandeul (1814-1900), are descended from his marriage to Eugénie Cardon.

An interesting fact is that his brother Didier-Pierre Diderot also lived in Paris to study from 1743 to 1744. He attended a Catholic seminary (séminaire diocésain) and also studied jurisprudence. On Friday, December 9, 1746, he finished his studies and went back to Langres. Diderot”s relationship with his brother was always difficult. The invitation to the wedding of Marie-Angélique was answered rudely and he did not come. On November 14, 1772, there was the final break between the brothers.

Other private relationships

His wife, the mother of his children, was the soul of his house, and Diderot also tolerated her strict religiosity. During his marriage, he had other intimate relationships: From 1745 he was involved with Madeleine de Puisieux, an “aventurière” (“adventuress”), as emancipated and unmarried women (usually of better origin and education) were called. In 1755, Diderot met Sophie Volland, who became a lifelong companion, soul and intimate friend to him; both kept up a lively “sensitive” correspondence. It was the year of the Lisbon earthquake, which, among other things, reopened the discussion of theodicy. From spring 1769 to 1771, Diderot had another intimate relationship with Jeanne-Catherine Quinault, whom he had known since 1760. In August 1770, he met with her and her daughter in Bourbonne-les-Bains and took a cure with them at the thermal baths there. Shortly thereafter, he wrote Les Deux Amis de Bourbonne (“The Two Friends from Bourbonne”).

Paris – the time of the consolidating Enlightenment

Diderot continued to socialize with Parisian intellectuals, at the Café Procope, also at the Café Landelle. This is how he met Alexis Piron. Through this circle, he came into contact with the salonnière and writer Louise d”Épinay, as well as Paul Henri Thiry d”Holbach. He became part of the so-called coterie holbachique.

Diderot played chess regularly at the Café de la Régence on the Place du Palais-Royal. He was friends with François-André Danican Philidor, the best player of the time; both families met regularly. Philidor”s chess teacher, François Antoine de Legall, a regular visitor to the café, was later memorialized by Diderot in Le Neveu de Rameau.

Diderot”s philosophical views had meanwhile moved far away from the Christian ones of his parental home. His doubts about this, his transition to a rational theism, became public in 1746 with the essay Pensées philosophiques, probably written at Easter. Although published anonymously, it made him known to a wider readership. The work, which was critical of religion, was condemned by the Paris Parlement and publicly burned. The further development of his positions toward a more unequivocal materialism is marked by La promenade du sceptique (1747) and the Letter on the Blind for the Use of the Seeing (Lettre sur les aveugles à l”usage de ceux qui voient, 1749), and later by the Pensées sur l”interprétation de la nature (1753).

From 1747, work on the Encyclopédie took center stage. In 1749, however, it was interrupted.

Imprisonment (July 24 – November 3, 1749)

The Minister of War of France, Marc-Pierre d”Argenson, requested on July 22, 1749, the Lieutenant General of Police Nicolas René Berryer to issue a royal warrant (lettre de cachet) for Diderot. On July 24, 1749, at half past seven in the morning, Diderot was arrested by Joseph d”Hémery, commissioner and inspector of the royal censorship office. He was interrogated and taken to the Vincennes fortress, château de Vincennes.

Diderot was accused of publishing the Pensées philosophiques and the Letter on the Blind for the Use of the Sighted, in which he had set out his materialist position, as well as of working on other writings directed against religion. Two years earlier, he had already been denounced as a “godless, very dangerous man” by the pastor of his parish, Saint-Médard, Pierre Hardy de Lévaré (1696-1778). A certain role is also said to have been played by the fact that an influential woman, Mme Dupré de Saint-Maur, wife of Nicolas-François Dupré de Saint-Maur, wanted to take revenge for a disparaging statement made by Diderot.

Rousseau visited him regularly in prison. The booksellers, interested in speedy work on the Encyclopédie, complained about the arrest. Diderot himself intervened by letter with René Louis d”Argenson and Nicolas René Berryer. On November 3, 1749, he was released. For this, he had to commit himself in writing not to publish any more blasphemous writings. In order not to jeopardize the progress of the Encyclopédie, he therefore left much unpublished in the following years.

The experience of his imprisonment made a deep impression on Diderot and made him proceed with greater caution in the future. Much later, on October 10, 1766, Diderot confessed in a letter to Voltaire, referring to his work on the Encyclopédie, that his soul was full of fear of possible persecution, but that he would not flee nevertheless, because an inner voice commanded him to continue, partly out of habit, partly out of hope that the very next day everything might look different.

Encyclopédie and major work (1747 to 1773)

The origins of the Encyclopédie lay in a translation of the two-volume Cyclopædia, or, An universal dictionary of arts and sciences, published by Ephraim Chambers in 1728, which the Englishman John Mills had been running since 1743 together with the German scholar Gottfried Sellius. To print their work, the translators turned to the publisher and royal court printer (imprimeur ordinaire du Roy) André-François Le Breton, who applied for a royal printing privilege, which was granted on February 25, 1745. In May 1745, Le Breton issued a prospectus promising the publication of a five-volume work by the end of 1748.

After Le Breton fell out with Mills – whose suitability as a translator remains doubtful – and appropriated the rights to the project, Jean-Paul de Gua de Malves was put in charge of its organization. The latter immediately suggested a fundamental revision, but soon gave up the direction of the project, fatigued by disputes. In 1747, Diderot took charge of the work on the Encyclopédie as editor, first with D”Alembert, and from 1760 with Louis de Jaucourt. Designing the overall plan, recruiting authors and organizing their cooperation, fighting for the printing privilege and against censorship, and also writing more than 3,000 articles himself was enough work for years to come. Where necessary, Diderot expanded his field of knowledge for this purpose. Thus, from 1754 to 1757, he regularly attended Guillaume-François Rouelle”s chemistry lectures. In the inevitable struggles, Diderot was also supported by the Freemasons; that he himself was a Freemason, however, is not proven.

During this time, Diderot also wrote novels and stories, plays for the theater, and worked on a theory of theater and epistemology. Much of this was not published at first, but some of it already came to the public through transcripts. Jacques-André Naigeon, who also served as d”Holbach”s secretary, became an important collaborator, editing and revising texts and also writing for the Encyclopédie. He later published a first, albeit incomplete, edition of his works in 1798.

Despite all this work, Diderot participated in the lively social life of the philosophes – the critically minded Parisian intellectuals, such as Condillac, Turgot, Helvétius, and d”Holbach – as well as attending aristocratic salons. From the winter of 175253, he also had correspondence with Madame de Pompadour, who, according to Marc-Pierre d”Argenson”s journal, had established contact with the encyclopedists in 1752. Later, she received some of them, including Diderot, for informal dinners and conversations.

However, there were tensions. In 1757, Diderot complained to Grimm about an invitation by d”Holbach to the Château du Grand Val: he doubted whether he should accept it, since the baron was a “despotic and capricious man. Later, however, he stayed there several times, as well as at the Château de la Chevrette in Deuil-la-Barre, the property of Louise d”Épinay. In letters to Sophie Volland, Diderot described his daily routine at the Grand-Val: in addition to reading, thinking, and writing, walking and talking with d”Holbach, general conversation, and meals included Tric Trac and Piquet.

In July 1765, Diderot finished work on the Encyclopédie. For almost 20 years, he and his family had lived off payments from publishers and booksellers; he had no rights to royalties. So now the only income came from his father”s inheritance from Langres. Dmitri Alexeyevich Golitsyn and Grimm saved the situation. They arranged the sale of Diderot”s library to Catherine II of Russia – it was shipped to St. Petersburg after his death (at a transportation cost of 16,000 livres). Catherine II also remunerated him throughout his life as librarian of his own library with 1000 livre per year and provided him with money for new acquisitions. In 1773, Diderot went to the court of Saint Petersburg for a few months.

The money enabled his daughter Marie-Angélique to take harpsichord lessons from 1765, first until 1769 with the pianist Marie-Emmanuelle Bayon Louis, then with the music theorist and composer Anton Bemetzrieder. In 1771, Bemetzrieder made her a main character in his musical textbook, Leçons de Clavecin, et Principes d”Harmonie.

Diderot”s library (like Voltaire”s) became part of the Russian National Library, founded in 1795. Like the rest of its holdings, however, it was later dispersed, and an accompanying inventory was lost. It could be reconstructed only incompletely through the registers of the publishers who supplied Diderot with books.

Journey to the court of Catherine II in St. Petersburg (1773 to 1774)

Tsarina Catherine II had already invited Denis Diderot to Russia in 1762, where he was to complete the Encyclopedia. Diderot declined, but remained in contact with the general and school reformer Ivan Ivanovich Bezkoi, possibly to publish a second edited edition of the Encyclopedia in Russia later. When Diderot left for Russia in 1773, the Encyclopedia was completed, his daughter was married, and he was indebted to his patron.

On June 11, 1773, Diderot left Paris for his only longer journey with the destination Saint Petersburg. The journey – with many meetings on the way – went first via The Hague to the Duchy of Cleves, where he met his later travel companion Alexei Vasilyevich Naryshkin. In The Hague, he stayed with the Russian ambassador Dmitri Alexeyevich Prince of Gallitzin (1738-1803) and his wife Amalie of Gallitzin (see also Münster Circle) until August 20, 1773. After a break due to illness, Diderot continued to the Electorate of Saxony. Via Leipzig, which he reached on September 2, 1773, to meet, among others, the theologian and hymn writer Georg Joachim Zollikofer, and Dresden, where he met the art theorist Christian Ludwig von Hagedorn, he continued – avoiding the Prussian residences of Potsdam and Berlin – to Königsberg, Memel, Mitau, Riga and Narva. On October 8, 1773, Diderot arrived at the Tsar”s residence on the Newa Bay.

In St. Petersburg, Diderot, weakened by an illness, first came to stay with Naryshkin and his older brother Semyon (1731-1807). There he still tended the bed at first. From October 15, 1773, Diderot was received by the tsarina – sometimes three times a week – for regular audiences. As a representative of enlightened absolutism, she hoped that this would provide inspiration for her reform policy. She had already corresponded with Voltaire and had shown herself inclined toward the French Enlightenment thinkers ever since she published her extensive Instruction on Legal Principles to the Russian Legislative Commission, the Nakaz (Russian Наказ, ”Instruction”), in 1767, in which she had borrowed heavily from the writings of Montesquieu in particular. The task of the newly formed commission was to create a system of uniform jurisprudence for the entire Russian Empire.

During his stay, Diderot hardly had the opportunity to get to know the conditions in the tsarist empire in detail and directly, so that his recommendations had to remain generally abstract. He recorded the content of his conversations with the tsarina in the Entretiens avec Catherine II. He supported, for example, the effort to establish a uniform administration of justice, but strongly criticized the autocratic absolute monarchy.

The conversations and experiences in St. Petersburg made Diderot later, especially in his discussion with the Tsarina”s Nakaz under the title Observations sur l”instruction de l”impératrice de Russie, clearly move away from the “monarchy pure” cast in laws, as Catherine II had in mind. He propagated happiness and freedom as the goals of all societies and as a task that rulers had to set themselves in preparation for the future. He called for the complete abolition of serfdom and an end to the influence of church political power. In the aftermath, Diderot, guided by the model of popular sovereignty, expected the empress to clearly self-restrain her absolute power.

The tsarina learned this only after Diderot”s death. Before his departure, she commissioned him to develop a plan to reform the Russian educational system in order to spread the ideas of the French Enlightenment throughout the tsardom. Diderot wrote Plan d”une université pour le gouvernement de Russie ou d”une éducation publique dans toutes les sciences (“Plan of the entire school system for the Russian government or of a public education in all sciences,” 1775). In it, for example, he demanded that academic education should not be oriented solely to the immediate usability by the crown or to reasons of state. Grimm brought the treatise to Russia.

To Louis-Philippe de Ségur, the French envoy in St. Petersburg from 1783 to 1789, the tsarina said: If she had incorporated all of Diderot”s ideas and conceptions into political action, the entire tsardom would have been turned upside down. And she told Diderot at the end of his stay in Russia that she listened to his brilliant explanations with the greatest pleasure, but that unlike him, she did not work with paper, but with people.

On November 1, 1773, Diderot and Grimm were admitted to the Russian Academy of Sciences as membre étranger by order of the tsarina. The academicians present showed “a very subdued enthusiasm” about this. Diderot presented the Academy with a catalog of 24 questions on the natural history of Siberia. Erik Gustavovich Laxmann was commissioned to answer them. During his stay in Saint Petersburg, Diderot endeavored to learn the Russian language. He was frequently invited to the palaces of Russian aristocrats.

On March 5, 1774, he began his return journey by stagecoach. Via Hamburg and Osnabrück, he returned to The Hague, where he arrived on April 5 and then stayed for some time. It was not until October 21, 1774 that he was back in Paris. In his treatise Essai sur la vie de Sénèque le philosophe, sur ses écrits, et sur les règnes de Claude et de Néron 1778, Diderot defended the tsarina against the accusation that she had been a spousemurderer of Peter III of Russia, similar to Iulia Agrippina, who murdered her husband, the Roman emperor Claudius.

The period after the trip to Russia until his death

Diderot”s health deteriorated visibly after his return from Russia. Heart and circulatory problems troubled him, and he suffered from swollen legs and shortness of breath. In 1774 he wrote to Sophie Volland that he expected his end in ten years. More often than before, he moved to his alternative quarters in Sèvres or to the Château de Grand-Val estate of his friend d”Holbach.

For the last time, Diderot was to narrowly escape being imprisoned again. In 1782, in the then independent principality of Bouillon, a second edition of his attempt on Seneca and his times appeared under the simplified title Essai sur les règnes de Claude et de Néron. The Paris police lieutenant Jean-Charles-Pierre Lenoir allowed Diderot to purchase a few copies of it for his own use past the Paris booksellers” guild. Diderot now obtained six hundred copies. The Parisian booksellers saw their earnings diminished by this and denounced Diderot. The process also involved the keeper of the seals, Armand Thomas Hue de Miromesnil (1723-1796). According to Lenoir, King Louis XVI demanded Diderot”s punishment. Diderot was summoned, but was able to refute the accusations, especially since the administration had a certain sympathy for him. He performed a rhetorical genuflection and still appeased his “accusers” by a retraction. Diderot met regularly with the police lieutenant Lenoir, who was a liberal spirit and a member of the lodge.

In February 1784, in a winter marked by extreme cold, Diderot”s longtime friend Sophie Volland died at the age of 67. She was followed in April by his granddaughter Marie Anne Caroillon de Vandeul, ”Minette” (b. 1773), aged ten. On February 19, 1784, Diderot suffered a sudden collapse, possibly a heart attack, accompanied by heart failure (acute or exacerbated). He died at lunch on Saturday, July 31, 1784. An autopsy the following day found an enlarged liver, an enlarged heart, and a left pleural effusion, as well as marked edema. The autopsy was performed by surgeon François Dominique Lesné, among others, and the findings are part of the Fonds Vandeul. Anne-Antoinette Diderot, the wife, and the son-in-law Abel François Nicolas Caroillon de Vandeul (1746-1813) organized the burial in the parish church of Saint-Roch in Paris. For this purpose, a sum of 1800 livres was discreetly promised to the priest as a donation. The ceremony is said to have been attended by 50 priests. Denis Diderot was buried in the ossuary below the high altar. During the French Revolution, on February 4, 1796, the ossuary, Diderot”s tomb and his remains were demolished by soldiers stationed there.

Diderot conducted a multitude of more or less intense relationships with the most diverse personalities of his time. These relationships were characterized by a high degree of individual specificity and dynamism with his counterpart, but thus also of varying duration and conflictuality in their direct personal or postal manifestations.

Only the cooperation of many made the Encyclopédie possible, which required intensive relationships between Diderot and other thinkers. These – especially those with Rousseau and Voltaire, Grimm and d”Holbach – also fertilized the rest of his work.Diderot”s style of speech and discussion, according to the assessment of others, was characterized by frequent rapid speech, his explanations were exceptionally lively and moving with a tendency to digress. Jean-François Marmontel testified to his stirring eloquence that enlightened all minds, and another encyclopedist, André Morellet, attested to his overflowing with ideas and his gift of linguistic wit to his interlocutors.

Le Rond d”Alembert

Among the three who regularly met for dinner at the Hôtel du Panier Fleuri, not far from the Palais Royals, was Jean-Baptiste le Rond d”Alembert, in addition to Rousseau and de Condillac. As co-editor and author of many entries in the Encyclopédie, especially those on natural science and mathematics, he wrote – in November 1757 in the seventh volume of the work – a lemma on “Genève.” In May 1741, Le Rond d”Alembert had been admitted as a member of the Académie française. Le Rond d”Alembert was in constant postal contact with Voltaire, who encouraged him to write the aforementioned lemma on “Geneva. The latter may not have been entirely free of intrigue. In the process, le Rond d”Alembert was tempted to take many a side swipe at the culture of the city, which caused a small uproar and spurred Voltaire from Geneva to a dense correspondence with many participants. With the result that le Rond d”Alembert withdrew from the encyclopedic project on January 7, 1758. A distantly polite relationship existed between the two men. After Diderot wrote Le rêve de D”Alembert in 1769, the protagonist of the work was incensed and, according to Jacques-André Naigeon, demanded that the manuscript pages be burned in his personal presence. Diderot attempted a new version of the trilogy and refrained from publishing the dialogues; however, circulating copies of the original text allowed it to be published later.

And another difference was noticeable between the two philosophes. While Diderot and the Russian tsarina came into contact after her enthronement in 1762, D”Alembert established steadily more intensive contact with the Prussian king Frederick II from 1746 on. For both philosophes, these monarchs remained, though not without contradiction, “persons of reference.” Both supported the philosophes financially. Thus, D”Alembert received a pension of 1200 livres from Frederick II starting in 1751.


When Jean-Jacques Rousseau came to Paris in the summer of 1742, he met Daniël Roguin, who would later become a banker, and through him he soon met Diderot; both became close friends. Diderot, in turn, became acquainted with Étienne Bonnot de Condillac through Rousseau, who already knew him. These three now met regularly. While there, they agreed to publish a literary criticism journal, Le Persifleur. Rousseau edited the first issue; a second one never appeared.

During his imprisonment in Vincennes, Diderot was supported by Rousseau. The latter asked for Diderot”s release in a written petition to Mme de Pompadour. Around 1750, Rousseau met Melchior Grimm, who also introduced him to Diderot.

In the mid-1750s, however, Rousseau ended his close relationship with Diderot. The reasons were his difficult personality and paranoid ideas, which, however, were not entirely unfounded. Diderot, however, remained friendly to him throughout his life. Rousseau”s relationship with Grimm also broke apart between 1756 and 1757 due to entanglements and the rivalry over Mme Louise d”Épinay.


Diderot had long been an admirer of Voltaire, praising his behavior in the Jean Calas affair. The relationship later became more distant. In February 1778, Voltaire was in Paris for the premiere of his play Irène. Whether he also met Diderot on that occasion is disputed. Voltaire also chose Frederick II as his “monarch of reference”.

Melchior Grimm

The friendship with Grimm was also of changing intensity in its course. At a festivity of the secret diplomat and Oberhofmeister Baron Ulrich von Thun (1707-1788), Grimm met Jean-Jacques Rousseau in the summer, more precisely in August 1749, in a country house in Fontenay-sous-Bois, whose owner was Frederick Louis of Saxe-Gotha-Altenburg. Through the latter, he then made the acquaintance of Diderot. At the beginning of their meeting it was carried by extraordinary sympathy to each other as well as of both to Louise d”Épinay. Grimm and Diderot worked on joint projects, such as the Correspondance littéraire, philosophique et critique and the Encyclopédie. Later, Grimm arranged the sale of Diderot”s library to the Russian tsarina, thereby freeing him from a financial bottleneck. The friendship ended late, however: Grimm rejected the colonial-critical analysis History of the Two Indies by Guillaume Thomas François Raynal, written in 1772-1781 with Diderot”s collaboration. Diderot wrote him a letter about it on March 25, 1781, Lettre apologétique de l”abbé Raynal à monsieur Grimm, but it never reached Grimm. Diderot was disappointed by Grimm”s subaltern and egoistic attitude, by his increasingly monarchist, absolutist positioning.


It is not known how Diderot and d”Holbach met. Most of their correspondence has been lost. Presumably, they were initially united by their interest in music. Both followed natural history topics, such as chemistry, with great interest. Diderot edited d”Holbach”s most important work, the System of Nature. Their friendship lasted a lifetime. D”Holbach kept away from commitments to European monarchs.

The Encyclopédie (1747 to 1766)

In a certain way, the “Encyclopédie” pursued the goal of linguistically capturing everyday factual contexts – “that is, the ability as such, without being able to say how” – of its time and making them explainable in a “how” with detailed illustrations and additions by the text; comparable to a distinction between implicit and explicit knowledge, as an expression of a linguisticizing process of explication of the implicit.

Example: A toddler learns the grammar of the mother tongue implicitly, i.e. via pattern recognition. A child in school generally learns the grammar of a language explicitly, i.e. via rules.

In 1745, Paris publisher and court printer André Le Breton planned to publish a French edition of Ephraim Chambers” 1728 English work Cyclopaedia, or Universal Dictionary of the Arts and Sciences, originally in two volumes, which contained historical, biographical, and geographical texts.

Initially, Le Breton teamed up with John Mills, an English-born author of agricultural textbooks, and Gottfried Sellius, a lawyer and naturalist from Danzig. While he was to provide funding, the two were to translate Chambers” two-volume work into French. The contract between Le Breton, Sellius and Mills was signed on March 5, 1745 and broken in August of the same year.

Le Breton, dissatisfied with the progress of the translations, accused John Mills of not knowing French well enough and also of not keeping to the agreed deadlines. On August 7, 1745, the two had an open, physical dispute. Le Breton was sued by Mills for assault and battery, but was acquitted.

Le Breton initially entrusted the management of the encyclopedia project as editor to the clergyman and mathematician Jean Paul de Gua de Malves. The latter planned a redesign of Chambers” Cyclopaedia and wanted to adapt it to current conditions. Since Le Breton alone could not raise the necessary funds for the project, he joined forces with three other publishers: Antoine-Claude Briasson, Michel-Antoine David, Laurent Durand. In 1747, however, de Malves gave up his participation in the project.

Now Diderot became the leader of the project, having already translated from English a history of the ancient Greeks, a medical dictionary, and a philosophical treatise by Shaftesbury.

From the beginning, the Encyclopédie was conceived as an exclusively collaborative project; in this respect, it differed in part from other encyclopedias and dictionaries. Another innovation was the introduction of cross-references.

In his Dictionnaire historique et critique (1697), the early French Enlightenment philosopher Pierre Bayle used an elaborate type area in the form of single- and double-column typesetting combined with footnotes and marginalia that were reproduced on the right.This “Baylean method” found its way, albeit in a modified form, into Diderot”s Encyclopédie (see also Encyclopedia).

Some of the authors plagiarized texts or text passages from other encyclopedias; Johann Heinrich Zedler”s Grosses vollständiges Universal-Lexicon Aller Wissenschafften und Künste (1732-1754), for example, was the source for many philosophical articles by Jean Henri Samuel Formey. Zedler”s work, for its part, had taken much from Johann Georg Walch”s Philosophisches Lexicon (1726).

But nearly three more months passed before, on October 16, 1747, Diderot and Jean-Baptiste le Rond d”Alembert were named editors of the Encyclopédie. Diderot, now in charge of the project, changed the original plan of a mere translation and adaptation of the text into French and decided to considerably expand the two-volume work to make it a summa of all the knowledge of its time. To this end, he first enlisted as collaborators his friend D”Alembert, a mathematician and natural scientist, and gradually other authors, the so-called encyclopedists, some of whom were otherwise little-known specialists, while others were famous personalities, such as Montesquieu or Voltaire. On April 30, 1748, the royal printing privilege, Approbation et Privilège du Roy, was granted.

Because of his imprisonment in the fortress of Vincennes from July to November 1749, he had to suspend his work on the Encyclopédie for several months and was freed by a written undertaking not to publish any more blasphemous writings. In the future, he was therefore more cautious and, in order not to jeopardize the progress of the Encyclopédie, left many other writings unpublished.

In October 1750, Diderot announced in his prospectus that an edition of the Encyclopédie with eight volumes and six hundred plates would be published. Although Denis Diderot and D”Alembert saw human knowledge woven into a system, they chose an alphabetical order for the presentation of their nearly 61,000 articles, so in the first final version of the Encyclopédie. Initially, they also saw the Encyclopédie as an overview of the state of knowledge of their time.

Diderot himself wrote a number of articles on the history of philosophy, but he also wrote articles on aesthetics, grammar, rhetoric, and even pedagogy and politics. Especially with the latter he put himself in a dangerous situation. An important contribution with over a thousand entries was made by him on the mechanical arts (crafts). In addition, there were the supplementary articles from the most diverse areas, which became necessary for the most diverse reasons, so entries on agriculture and the lemma animal were edited by Diderot.

An important contribution to the completion of the Encyclopédie was made by Louis de Jaucourt, who joined the project around 1751 after D”Alembert”s withdrawal. Although the relationship between Diderot and de Jaucourt could rather be characterized as cool, the latter appreciated his literary work and his diligence, which also left him time for writing other works.

Three areas are significant: the sciences, followed by the liberal arts and the mechanical arts. For this purpose, it was necessary to clearly assign words and terms to a thing or a factual context. In the field of the mechanical arts, for example, i.e. the skills and techniques of craftsmen and artisans, many discussions were held with the people involved in order to bring order to the facts. Nevertheless, there were no distinguished occupations for the encyclopedists that stood in contrast to the everyday ones.

For Diderot and his collaborators, moreover, it was exceedingly important not only to capture the workings of the technologies of their time linguistically, but also to illustrate them to the reader or viewer by supplementing the text with detailed illustrations through engravings: Accordingly, in the section on agriculture, those machines and tools that were used for the work are depicted alongside a pastoral landscape scene with hills and the people working in these areas.

However, this alphabetical structure also enabled Diderot to evade the censors at times. Knowing that the representatives of the authorities were particularly focused on terms and articles with political and religious explosiveness, he often placed his Enlightenment ideas and criticisms among “trivial” topics.

The protagonists of the technical sciences in the 19th century implicitly oriented themselves on this normative program of the Encyclopédie in the sense of the abolition of the encyclopedic in the form of the system of classical technical sciences.

In 1750, he wrote a prospectus that was sent throughout Europe, inviting interested parties to subscribe to the Encyclopédie. In November 1750, the first eight thousand copies of the Prospectus, the preliminary announcement of the Encyclopédie, were published, inviting buyers to subscribe. Initially, eight volumes of text and two volumes of engravings were planned. In a later published edition from the year 1755, Diderot speaks in the article on the term encyclopedia in Volume V of a total of twelve planned volumes.

1751 erschienen die beiden ersten Bände der Encyclopédie ou Dictionnaire raisonné des sciences, des arts et des métiers.

The bookseller”s success of the work was enormous, but the Jesuits and influential representatives from the Sorbonne diagnosed an unchristian tendency and obtained a ban from the royal crown council, Conseil du roi de France. However, since Mme de Pompadour, some ministers, many influential Freemasons, and the chief censor Chrétien-Guillaume de Lamoignon de Malesherbes were on the side of the encyclopedists, four more volumes were published from 1753 to 1756 despite the ban. After all, Malesherbes, as chief censor, Censure royale, had granted the Encyclopédie the royal printing privilege in 1751. Malesherbes sympathized with the Enlightenment thinkers in a dual position. He was a servant of the French monarchy in various capacities – under Louis XV and Louis XVI. But he saved the publication of the Encyclopedia in 1752 and prevented Diderot from being arrested again. Although the first two volumes of the edition were banned, Malesherbes managed to ensure that the royal decree did not explicitly revoke the printing privilege.

This happened against the following background: The first volume of the Encyclopédie appeared in January 1752, the printed date of June 1751 in the title page is incorrect. The first repression of the Encyclopédie by state institutions was thus in 1752, prompted by the theological dissertation of Jean-Martin de Prades. Reviewed by the Irish professor Reverend Luke Joseph Hooke (1716-1796), who in the end lost his office and dignities. On November 18, 1751, de Prades defended his thesis at the Sorbonne. But soon after, his dissertation for the doctor theologiae was suspected of dubious fidelity to dogma – i.e., proximity to the Encyclopédie – so that the academic authorities subjected his work to close scrutiny.

On December 15, the commission of the Paris theological faculty dealing with the case determined that the theses expressed in the dissertation were to be rejected and that the writing itself fell under the censorship regulations. For the second volume of the Encyclopédie, published in January 1752, de Prades wrote an article of about fifteen pages under the term Gewissheit, Certitude. De Prades” article was framed by an introduction and a laudatory conclusion by Diderot. Against the background of the controversy over his dissertation, the theologians now expressed outrage and accused de Prades of heresy. An arrest warrant was issued against de Prades, and he fled to Holland and finally to Berlin. The first two volumes of the Encyclopédie, already published, were banned on February 7, 1752, as were the remaining volumes. Chrétien-Guillaume de Lamoignon de Malesherbes, chief censor of the Censure royale, intervened protectively.

Malesherbes diverted the crisis in such a way that on February 2, 1752, a council decree, arrêts du Conseil, identified only passages in the first two volumes that “had a destructive effect on the royal authority and strengthened the spirit of independence and revolt and promoted the foundations of error, moral corruption, irreligion and unbelief with ambiguous terms. However, this had no effect on the distribution of the Encyclopédie, as the first two volumes had already been delivered to buyers or subscribers. Above all, the printing privilege was not revoked. Malesherbes also received support in this matter from Mme de Pompadour.

After that, however, pressure from opponents grew. In 1758, the ban was renewed, and in 1759 Pope Clement XIII placed the work on the Index. In the meantime, the government had learned to appreciate the foreign exchange revenue that came in from all over Europe through the sale of the Encyclopédie, despite the Seven Years” War (1756-1763), and Diderot was encouraged to continue under the table.

The co-editor Jean-Baptiste le Rond d”Alembert withdrew from the project in 1759. He was replaced in 1760 by the very committed Louis de Jaucourt.

On November 12, 1764, Diderot discovered by chance that his publisher André Le Breton had, without consulting him, made changes in the last volumes of the text by omitting whole passages and making serious changes to the text. Although Diderot initially wanted to give up any further collaboration with him, he did not let it get that far. In a letter to André Le Breton he wrote:

In early 1766, the 17th text volume was published, and in the 1772 edition of the Encyclopédie, the project was finally completed with the eleventh volume.

Diderot devoted 20 years of his life to this project. He wrote more than 3000 articles before bitterly ending the project in July 1765 for lack of recognition. Diderot retired and left the publication of the last volumes of illustrations to his successors, who, like the first, contributed much to the fame of the enterprise. According to the contract with the publishers, he was to receive 25,000 livres for the completed encyclopedia. Voltaire complained about this small amount for a twenty-year or presumed twelve-year work in a letter of April 14, 1760, to Jean-Baptiste le Rond d”Alembert.

In the Encyclopédie méthodique – in 166 volumes, published from 1782 and 1832 by the publisher Charles-Joseph Panckoucke and Mme Thérèse-Charlotte Agasse (1775-1838) – the Encyclopédie ou Dictionnaire raisonné des sciences, des arts et des métiers finally found its reworking, expansion and redivision into various specialized encyclopedias.

André François Le Breton and his three business partners Antoine-Claude Briasson, Michel-Antoine David and Laurent Durand signed a partnership agreement traité de société on Monday, October 18, 1745, with an initial capital of 20,000 livres and a distribution of shares according to the contributions. Le Breton held a share of 50 percent, the others one sixth each.

Many of the books published in the 18th century appeared in an average edition of 500 to 1000 copies. The Prospectus of the Encyclopédie, published in November 1750, was planned with 8000 copies. Buyers were to be invited to subscribe. Eight volumes of text and 2 volumes of engravings were announced. According to the plan, they were to appear at intervals of about half a year. Thus, Volume II would have appeared in December 1775, Volume III in June 1776, and so on, until finally Volume VIII was to be made available to the public in December 1779. The subscription provided for an advance payment of 60 livre and, upon receipt of Volume I, another 36 livre, for Volumes II through VIII 24 livre, and for the last two volumes with the engravings 40 livre. The total cost was 280 livre, and if we assume an approximate exchange rate of 1 livre equals 10 to 12 euros, the total price would be 3000 to 3400 euros. In fact, Volume I was published in June 1751, Volume II in January 1752, Volume III in November 1753, Volume IV in October 1754, Volume V in November 1755, Volume VI in October 1756, Volume VII in November 1757, Volumes VIII to XVII from 1765 to January 1766, and the last volume with the plates and engravings in 1772. In this first version, the work contained 60,660 items.

When Diderot joined the original project of translating the English edition Cyclopaedia, or Universal Dictionary of the Arts and Sciences by Ephraim Chambers in 174647, under the publishing aegis of Le Breton, he received 60 livres for his work in February, 45 livres in March, 90 livres in April, and 120 livres in June. In October 1747, Diderot and d”Alembert negotiated a new contract with the publishing community around André François Le Breton, Antoine-Claude Briasson, Michel-Antoine David, and Laurent Durand. The contract stipulated that Diderot should receive 7200 livre, 1200 livre after the publication of Volume I and the further 6000 livre in a rate of 144 livre in the following months. Converted, this would be, see above, about 78,000 to 90,000 euros.

When Diderot visited his family and acquaintances in his hometown of Langres for an extended period of time in November 1754, a notary Dubois who lived there advised him to renegotiate his contract with the publishers. The new terms stipulated that Diderot would receive 2,500 livre for each volume completed and another 20,000 livre at the conclusion of the Encyclopédie project.Diderot presumably received about 80,000 livre for his 25 years of work on the Encyclopédie, the equivalent of an average of 32,000 to 38,000 euros per year. The Paris publishing community under Le Breton made a profit of 2. 5 million livre, a century of publishing. Worldwide, around 25,000 copies of the Encyclopédie were sold in various editions by 1789.

When the Encyclopédie project was at its peak, a larger number of craftsmen and other professions were directly or indirectly involved: Engravers, draftsmen, typesetters, printers, and bookbinders, to name a few. The Encyclopédie comprised 17 volumes of articles from 1751 to 1765 and eleven volumes of illustrations from 1762 to 1772, 18,000 pages of text, 75,000 entries, including 44,000 major articles and 28,000 minor articles, totaling 20 million words.

The target audience for the costly and extensive Encyclopédie was presumably wealthy and probably educated people from the bourgeoisie, nobility and clergy. Furthermore, it can be assumed that the number of readers was greater than the number of owners.

Early philosophical works

Besides the Encyclopédie, Diderot always had other works in progress. Thus, the translation of Shaftesbury”s Inquiry was more than a translation into French. Already by its expansive title Principes de la Philosophie morale ou essai de M. S***. sur le mérite et la vertu. Avec Réflexions (1745) showed the commentary character of this work, which was provided with extensive accompanying texts that made Diderot”s own position clear. Already in 1746, following the Shaftesbury translation, he had published his Pensées philosophiques (“Philosophical Reflections”), in which he developed for the first time materialistic and atheistic ideas of a radical Enlightenment philosopher. In 1748 he also published the erotic novel Les bijoux indiscrets (“The Chatty Little Things”), which became a scandalous success.

In the Pensées sur l”interprétation de la nature (“Thoughts on the Interpretation of Nature,” 1754), Diderot acted as a theoretical natural scientist. The text was a plea for the principle of experimentation and against the rational explanations of nature of the Cartésiens, the rationalist thinkers in the wake of René Descartes. Diderot sees the process of knowledge as an interaction between observation, combining reflection and experiment. The world seems fundamentally recognizable to him; he rejects agnostic positions as well as a knowledge of nature based exclusively on mathematics or its overemphasis, the latter in contradiction to D”Alembert and his Essai sur les éléments de philosophie (1759). But also the critical appreciation of the philosophical positions of a Pierre-Louis Moreau de Maupertuis, presented in his Système de la nature ou Essai sur les corps organisés – first published in 1751 in Latin as Dissertatio inauguralis metaphysica de universali naturae systemate and under the pseudonym “Dr. Baumann aus Erlangen” – in which the latter dealt with Leibniz”s theory of monads and its significance for natural philosophy, were incorporated into Diderot”s Pensées sur l”interprétation de la nature.

This text, aphoristically divided into short articles, so to speak, bases knowledge on three tools: observation of nature, reflection, and scientific experiment. In this approach he was connected to the philosophy of John Locke and Isaac Newton (cf. article XV).

In article XXIV Grundriß der experimentellen Physik Diderot described its scope and its tasks (“(…) experimental physics is generally concerned with existence, properties and use”) and subsequently defines these and other terms derived from them. In Article XXIII he differentiates the types of philosophy: “We have distinguished two types of philosophy: experimental and rational philosophy.” In the following articles, a synthetic conclusion was sought from both aphorisms. From article XXXI on, examples and conjectures derived from them are formulated.

In general, the influence of John Locke”s thought on Denis Diderot was not insignificant; his most important work for epistemological sensualism, An Essay Concerning Humane Understanding (1690), had already been translated into French by Pierre Coste in 1690 under the title Essai sur l”entendement humain. Like the English sensualists, Diderot also assumed the sensual foundation of cognition, and thus also the primacy of expérience over raison in the cognitive process.

In 1749, the already mentioned philosophical work Lettre sur les aveugles à l”usage de ceux qui voient (“Letter on the Blind for the Use of the Sighted”) was published, in which Diderot, based on the thesis that a person born blind (see also Visual Perception) has no possibility to conceive the existence of God, doubts his existence at all. In this monograph, Diderot deals with the philosophical considerations of the blind Cambridge mathematician Nicholas Saunderson, whose thoughts were strongly influenced by atheistic considerations. But it was William Molyneux who first addressed this so-called Molyneux problem in 1688. Diderot adopts the “perspective” of the blind man and demands from the sighted to think themselves into his imagination. The Lettre sur les aveugles thus also revealed a change in Diderot”s conception. The deistic-pantheistic views represented in the Pensées philosophiques were replaced by more materialistic-atheistic ideas.

In 1751 he contributed to a foundation of philosophical aesthetics with the Lettre sur les sourds et muets, à l”usage de ceux qui entendent et qui parlent (“Letter on the Deaf and Dumb for the Use of the Hearing and Speaking”). In addition, Diderot here addresses the phenomenon of language and its connection with the sensory environment. In a kind of metaphysical anatomy (espèce d”anatomie métaphysique), he poses the sensualist consideration of how a human being would perceive his environment if individual sense organs were switched off, and asks how he could perceive the environment through only one sense organ, how the world would therefore present itself in each of the senses. In the Lettre sur les sourds et muets, Diderot sketches a scenario consisting of a group of five persons, each of whom would have only one sense and each of whom believed to perceive the world in its entirety. He concludes that these persons, thanks to their consciousness, memory, and capacity for abstraction, would be perfectly capable of generating, for example, a concept of number from their different perceptions and also of communicating about it. Analogous experiences of the different senses could lead to an abstract number concept and thus to a meaningful dialogue. On the other hand, the communicating persons would have to consider themselves mutually crazy; because each one judges everything with its individual sense performance.

In the same year, Diderot was admitted to Frederick II”s Royal Academy of Sciences alongside D”Alembert.

Diderot, especially in his philosophical writings, was almost enthusiastic about the idea of development, an idea that involved the entire universe. From the material substrate all life originates. Matter could thus also be living matter, which was thus capable of developing livingness and sensibility (sensibilité), without one having to assume a final causality in this development or bringing forth. In the final inaccessibility of this finality then also the human inability to understand nature according to its own measure is shown, in the assumption that in this inaccessibility lies the prohibition to subsume nature under the reason and the will of a God. God was thought with it as a human being increased into the infinite. Nature was the whole, the circle, in which all life emerged from each other. This whole had a temporal sequence, a development, so that the being got into a time flow. He saw in the matter the substance of becoming, which he imagined however less concretely than for instance his friend Paul Henri Thiry d”Holbach. If his interpretation of nature was to be scientifically founded on the one hand, it was at the same time a draft occupied with feeling and fantasy, which was later to be claimed in a similar way by Goethe.

Author of novels and dialogues

The novel is a fictional literary genre that only in the 18th century began to free itself from the prejudice that it was, according to some contemporary observers, frivolous, superficial, and immoral.

Diderot worked on novels and stories that, in retrospect, seem astonishingly modern, most of which appeared only posthumously. In 1760 and 1761, for example, he wrote La religieuse (“The Nun”), a sensitive novel critical of the Church, which describes the ordeal of an involuntary nun and is today his most widely read work (including one that has been made into a film) (it was not printed until 1796). Diderot was an admirer of the works of Samuel Richardson, and much of his novels Pamela, or Virtue Rewarded (1740) and Clarissa or, The History of a Young Lady (1748) found their way into La religieuse. While working on his novel Le Neveu de Rameau, Richardson died on July 4, 1761, and in his Éloge de Richardson (1760) praised him for raising the genre of the novel to a serious level. In this way he differed from Voltaire, but also from Rousseau, who were hostile to the innovator of the English novel. They were therefore counted among the anciens and not, like Diderot, among the modernes. In his passion for Richardson, Diderot even reproached his confidante, Sophie Volland, for her negative attitude towards the novel Pamela.

In general, the influence of English literature on Diderot was considerable. While his first publications were translations of English texts into French, followed by La religieuse, influenced by Richardson, Jacques le fataliste et son maître (1776) parallels Laurence Sterne”s The Life and Opinions of Tristram Shandy, Gentleman (1759-1767). Sterne, who stayed in Paris several times between 1762 and 1765 during his travels through France and Italy, where he also made the acquaintance of Baron d”Holbach, Diderot, and others, is considered an important inspiration for Jacques le fataliste. It is known that Sterne instructed his publisher in London to send him some of the already completed volumes of his edition of Tristram Shandy to give to Diderot. Later, Diderot wrote to Sophie Volland that with Tristram Shandy he was reading the “most foolish, wisest, merriest of all books.”

From 1760 to about 1774, Diderot wrote the experimental novel Le Neveu de Rameau (“Rameau”s Nephew,” first printed in Goethe”s German translation in 1805, in a French retranslation in 1821, in the finally rediscovered original text only in 1891).

The novel Jacques le fataliste et son maître, begun in 1773 and finished in 1775, was published in the manuscript journal Correspondance littéraire from 1778 to 1780 (it did not appear in print until 1796). As a frame story, Diderot chose the nine-day journey of the servant Jacques with his master to a wet nurse”s house to pay off the debt for caring for a child who had been underwritten to him. The journey provides the occasion to weave in other stories. The relationship between Jacques, the servant, convinced of the determinacy of all events but full of life and active, and his master, who believes in free will but is lethargic and passive, inspired Hegel to develop his dialectic of domination and servitude in the Phenomenology of Spirit, just as the ambivalent protagonist of the Neveu de Rameau inspired him to distinguish between “Ansichsein” and “Fürsichsein”.

Diderot”s unpublished writings with satirical tendencies reveal clear doubts about the optimistic, Enlightenment worldview he publicly espoused with the Encyclopédie. His one-time friend and later adversary Rousseau accused Diderot of having turned him away from optimism.

For Diderot, writing in dialogue form was very important in both plays and essays. He developed his thoughts in exchange with a virtual counterpart. These imaginary interlocutors were soon called listeners (auditeur), soon readers (lecteur) or interlocutors. Over time, a change also became apparent here: While the dialogue partners in the Entretien entre D”Alembert et Diderot (1769) as part of the trilogy of Le Rêve de D”Alembert and in Le Neveu de Rameau (1769) were still concrete persons, they became abstract interlocutors (interlocuteur) in the story Ceci n”est pas un conte (1773), The partner thus exhibited only a few personal traits, and the concrete personhood was finally further dissolved in Supplément au voyage de Bougainville (1772) as a conversation between A and B.

Language considerations

Diderot defined the term “language” very broadly – gestures and facial expressions belonged to it, non-verbal communication in general, especially melodic-rhythmic voice leading, more generally prosody. Articulate language, whether spoken or written, was for Diderot only one of the forms of human expression. He is in agreement here with Étienne Bonnot de Condillac. Diderot can be described as a sensualist who was also under the influence of the encyclopedist Charles de Brosses.

He set out his thoughts on the development of language in Lettre sur les sourds et muets à l”usage de ceux qui entendent et qui parlent (1751). He also responds here to Charles Batteux”s writings Les beaux-arts réduits à un même principe (1747) and Lettres sur la phrase française comparée avec la latine (1748). Another important discussant was the contributor to the Encyclopédie and founder of the linguistic typological approach Nicolas Beauzée.

Diderot saw language development as a process in which signs are increasingly replaced by words. However, when it came to the communication of emotions, extraordinary sensations or extreme mental states, he gave priority to gestures, gestural language, over spoken, word language. For him, language is more related to emotionality, affects, and thus to poetry and music, than to rational thought and logic.

In his Lettre sur les sourds et muets, Diderot attempts to trace the distinction between a natural order of language to an artificial language. Starting from the distinction of the natural objects of perception, he assigns a special role to adjectives. In natural languages they lead to the nouns, as it were from the properties to the objects. The language of gestures also follows this principle. In his reflections that a natural language presupposes an artificial language, Diderot clarifies the basic problem of the theories of language formation. For how does one arrive at the distinction of the objects of perception without having signs at one”s disposal? And, from what does one develop the criteria that, starting from adjectives (or properties), lead to the formation of nouns from the expression of ideas?

He also dealt with the considerations of a general syntax of the organ of thought. Until the time of the Enlightenment, it was thought that language also contained the basic categories of logic. In other words, one was convinced that the word also reflected the thing, that it was directly connected with it, or translated into modern terminology, that there was a unity of essence between signifier, the linguistic form, and signified, the linguistic content.

Diderot dealt with the concept of inversion, which was a central aspect of Port-Royal”s grammar in the 18th century. He also dealt with the considerations of César Chesneau Du Marsais and de Condillac on this.

For Diderot there was an original-natural, a property-centered and a later thing-centered word order. He also saw in the inversion, which should be inherent in all high-level languages, a recourse to the original-natural word order. Diderot takes the position of a nominalist in his theory: he negates any original connection between the word and the object.

Batteux, Du Marsais and de Condillac assumed that the first designations were formed by imitation of sounds, onomatopoeia. Diderot, on the other hand, thinks that the relation of a sound utterance to a thing, which is to be designated by it, was first established by gestures – there is no relation between sound utterance and thing that is directly comprehensible to the other person. In addition, he assumes a development of the stock of malleable sounds: starting with easily speakable sounds, the organs of articulation have successively become capable of forming more difficult ones through practice. He calls this original stage of language use langage animal. It is the state of a coexistence of sounds and gestures.

This stage was gradually replaced by that of the langue naissante. The vocabulary required for mutual understanding had essentially developed in the process. At first, only one sense was used to designate perceptible objects, i.e. object properties, and the first words were therefore predominantly adjectives. Then, beginning with the objects perceptible by several senses, nouns were formed. By abstraction from the sensually graspable qualities finally further, more general terms developed. Thus articles, nouns, adjectives and verbs were present, declension and conjugation were still missing. At this stage, gestures and facial expressions were still indispensable for understanding the linguistic statements.

Finally, the langue formée is formed. All parts of the linguistic statement are now syntactically linked, gestures are no longer necessary for understanding.

For Diderot, the temporal structures in the different languages were ultimately of decisive importance. He described the transition from the langue naissante to the langue formée with the concept of “harmonies,” by which he meant the qualities of sound, the rhythm in the combination of vowels and consonants as well as in the syntax, i.e., the arrangement of words. The simultaneity of both harmonies creates poetry.

For Diderot, language and words are always tied to experience, connotation, or association, and thus shape human thought.

His assumptions on the theory of perception and the beautiful

In a letter to John Locke dated July 7, 1688, William Molyneux posed the following problem, the Molyneux problem:

Assuming, according to Diderot, that after a successful eye operation the blind man could see clearly enough to distinguish individual things from one another, would he then immediately be able to give the same name to the things he sensed as to those he now saw? What could someone say who was not used to “thinking and reflecting on himself”?

The formerly blind person is very well able, for example, to distinguish a geometric body, such as a sphere, from a cube. In Diderot”s opinion, a formerly blind person would by no means need his sense of touch, but would need more time for his sense of sight to adapt to his task. So Diderot did not assume at all that for the solution of the Molyneux problem an aid of the sense of touch was indispensable.

He assumed that it was easier for educated persons who had been trained in philosophy, physics, or, in the case of geometric solids, in mathematics, to bring things perceived by feeling into agreement “with the ideas he had gained through the sense of feeling” and to convince himself of the “truth of their judgment”. He assumed that this process was much faster in persons trained in abstract thought than in persons who were little educated and had no practice in reflection.

Diderot, in his Letter on the Blind for the Use of the Sighted, Lettre sur les aveugles à l”usage de ceux qui voient, of 1749, comes to the assumption that the quality of perception is independent of the number of sense organs. Behind this is an empiricist position, for it is through the senses that perceptions enter the sensorium commune, the common sensorium. He draws for this sensorium commune in the Rêve de D”Alembert (the “spider” conceived as brain, in which all impressions and perceptual contents converge and the “spider”s web”, because all fibers of the senses end at the spider, and the touches of the web cause corresponding reactions in the latter. But if the perception is independent of the number of senses, the question arises about the security and reliability of the process of perception. Because in the result the content of the perception – independently of the kind of the sense organ – would be abstract, the contents would not deliver us a true image of the reality, but only realities in abstract signs which we could interpret thanks to the experience (expérience).

The (total) reality from reality, which is mediated by the sense perception, is not an absolute one for Diderot, but has only the character of a relative meaning. For each sense constitutes its own (sub-)reality, which only in their combination together enables a conception of man to reality. Missing sense facilities therefore necessarily lead to a modification of the (total) reality, which in its consequence would have a change of the mental and ethical sensitivities of man, a point of view, which he developed in particular in his letter about the blind ….

In this he contradicts Charles Batteux, who wrote in his Les beaux arts réduits à un même principe (1773) that the arts are imitations mediated by the human senses. Such an imitated nature does not present itself according to its essence, but in its appearance. Batteux sees this theory of imitation as the basis for all the arts; in other words, the same aesthetic laws apply to poetry as to painting and music. Diderot opposes such a unifying theory of the arts in his Lettre sur les sourds et muets (1751).

In the article on the beautiful (Beau), Diderot presents his views on the beautiful in a detailed discussion; it appeared in the second volume of the Encyclopédie in 1751. This essay was published separately as a preprint as early as 1750, indicating that it seemed significant enough to him to make it independently available to the public. It contains all the important considerations on Diderot”s aesthetics.

The beautiful appears in the perception of the person looking at it, but Diderot was convinced that the beautiful object itself could produce this effect. Diderot rejected the idea of an objective beauty, through his methodical approach to explaining his thoughts, he made it clear that the accent was on the perception of relationships (rapports). For Diderot, beauty was directly related to an abstracting concept of art.

If the goal of the visual and performing arts in the 18th century was to imitate nature – the sujets were sought in reality and the creative implementation was subject to normative rules – then the standard of evaluation was nature itself, and here the most perfect possible representation, i.e. the creation of an artistic reality, which thus contained the greatest amount of beauty and thus truth.

Diderot distinguished between the forms in the things and the forms of our imagination. Not our mind puts the form relation in the things, but it notices only the relations between both kinds of forms. Everything is beautiful that is able to awaken in the mind the idea of relations (rapports éloignés) within a multiplicity conceived as a unity, precisely as an expression of an abstracting concept of art. A multiplicity hidden in the reality organized by a network of connections. Beauty is not an absolute value; depending on whether the object to be considered is to be judged by itself or with other objects of its kind, different qualities of beauty result.

Diderot differentiated between a real beauty (beau réel), also “beauty apart from me” (beau hors de moi) and a perceived beauty (beau relatif), also “beauty in relation to me” (beau par rapport à moi). A beauty as beau réel consists in the harmonious relations of all its parts to the whole, the beau relatif of an object, on the other hand, is based on a higher number of rapports and thus represents a higher degree of beauty. Diderot points out that beauty is not an absolute value; a value judgment of beauty can only be attributed to the objects under the condition that human observers exist who can make such a value judgment based on the similarity of their physical and mental constitution.

For him, the act of artistic appropriation was related to scientific knowledge. Thus, for both sensual processes or relations to the object, truth was the goal. This is achieved by a correspondence of the judgment or in the beauty, for example, of the picture with the object. The degree of beauty of an object increases, if more than one relation (rapport) can be recognized. But this increase is limited by the fact that the number of relations is arbitrary or also unclear.

For Diderot, the perception of relationships is the basis of beauty, and everyday nature is, in a sense, the first model of art. Diderot understood nature as the whole of reality, which also included everyday human existence, and he drew attention to all facets of human relationships.

The art critic

In 1665, the Académie royale de peinture et de sculpture initiated an art exhibition, which was then made accessible to a larger public from 1667 and took place at more or less regular intervals. These exhibitions were held from 1699 in the Grande Galérie du Louvre also Cour Carrée, it was called for short le Salon. This salon also served the sale of art in association with Parisian gallery owners.

From 1759 until 1781, Diderot visited these salons, often together with Sophie Volland, and described his impressions and reflections in a total of nine salons. Even more, in the years that followed, he studied art history as well as the techniques of painting and became one of the first professional art critics with the nine articles he wrote about the Paris salons between 1759 and 1781 for the handwritten journal Correspondance littéraire, philosophique et critique of his friend Melchior Grimm.

In 1759, Diderot wrote down his first Salon with only eight pages. That of 1761 already had 50 pages and those of the years 1763 to 1767 had not only become even more extensive, but also clearly showed his development or individuation as an art critic. Diderot not only acquired expertise, but counted several painters among his circle of friends. In Diderot”s salons of 1769, 1775, and 1781, a stagnation in his evaluation of the visual arts is noticeable. He described basic things about his reflections in an aphorism-like manner in the monograph Pensées détachées sur la peinture, la sculpture, l”architecture et las poésie (1772).

He had become a connoisseur of painting, was able to discuss technical details, image design and arrangement as well as the effects that the paintings evoked. It was the artistic productions of François Boucher, Jean-Honoré Fragonard, Louis-Michel van Loo, Charles André van Loo, Jean Siméon Chardin or Claude Joseph Vernet that inspired his aesthetic reflections, for example under the term le beau in his Encyclopédie.

In the weightings of the individual art genres, parallels to the theater theory became apparent. Thus, although he saw in genre painting, i.e., the depiction of everyday action scenes, only a “simple imitateur, copiste d”une nature commune” and for classical history painting a “créateur d”une nature idéale et poétique,” in his Pensées détachées sur la peinture, la sculpture, l”architecture et la poésie (1772) he stated the following:

One takes from the quotation that ultimately certain forms of genre painting could appeal more to the sentiment of the viewer. Because they are not exclusive, they could show the general human more clearly.

For Diderot, beauty in the visual arts (les beaux-arts) would be expressed through the following conditions:

For Diderot, it is important to reach a judgment through unbiased, methodical observation of works of art. He did not base his observation on universal and timeless standards, but he prefers the representation of the original and everyday to the idealized and exaggerated. The sensual effect of the image, the sentiment of the viewer, is of greater importance to him than the assessment of the degree of technical perfection.

Diderot summarized his understanding of art, his theory of art, in a variety of letters and essays in literary journals or salon descriptions. Thus, there is no coherent theory of art by him (see also Aesthetics). Rather, he wrote about art in the form of reflections of his own subjective feelings and ideas. This created an immediacy, a great closeness to the viewed art object, which is evident in his explanatory descriptions and its effect on the viewer. Diderot mentions the works of Anna Dorothea Therbusch, including his portrait and its creation, in his Correspondance litteraire of 1767.

His work as an art agent for the Russian tsarina

After the sale of Diderot”s library to the Russian tsarina Catherine II in March 1765, mediated by Friedrich Melchior Grimm and Dmitri Alexeyevich Golitsyn, Diderot”s postal contacts with the tsarina became closer. In addition to his position as librarian of his own library, he was appointed as an imperial art agent and in 1767 as a member of the Russian Imperial Academy of Arts (Russian: Императорская Академия художеств).

Thus, Denis Diderot, together with Dmitry Alexeyevich Golytsin and Baron Grimm, among others, mediated the Crozat collection. It was originally created under the efforts of Pierre Crozat and sold to Saint Petersburg in 1772 with the support of Denis Diderot, so that today most of the Crozat collection is located there in the Hermitage. This unique collection – it contained works by Peter Paul Rubens, Rembrandt van Rijn, Raphael da Urbino, Titian and others – first passed to Crozat”s nephew Louis François Crozat (1691-1750) and after his death the art collection was given to Louis-Antoine Crozat, Baron de Thiers (1699-1770), who united it with his own collection, which contained mainly French and Dutch artists. Later, he also inherited the picture collection of his younger, childless brother Joseph-Antoines Baron de Tugny (1696-1751) and merged the collections. Louis-Antoine Crozat also continued collecting and again enriched the collection. The tsarina still had Étienne-Maurice Falconet advise her before the purchase, ultimately in October 1771 the collection or more than 400 paintings was acquired by Catherine II for 460,000 livres. As a thank you for the mediation, Diderot received noble sable skins, from which he had a winter coat made.

From the collection of Mme Marie Thérèse Rodet Geoffrin, Diderot acquired two paintings for the tsarina in 1772. Mme Geoffrin commissioned them for herself from Charles André van Loo in 1754. The collection of François Tronchin (1704-1798) was also arranged by Diderot; it contained nearly a hundred paintings by, among others, Philips Wouwerman, Nicolaes Pietersz. Berchem and Gabriel Metsu.

Diderot and the theater

Together with Pierre-Augustin Caron de Beaumarchais, Denis Diderot was one of the inventors of the bourgeois tragedy. He was on friendly terms with the French stage poet Michel-Jean Sedaine, and both had similar views on drama.

He admired Samuel Richardson”s novels Pamela, or Virtue Rewarded (1740) and Clarissa or, The History of a Young Lady (1748) – as stated in his Éloge de Richardson (1760) – because the latter succeeded in depicting moral themes in a vivid and exciting way based on everyday events and his fellow human beings. His novels made the reader forget that they were fictions. Diderot developed his doctrine of realistic detail (roman réaliste) from Richardson”s works. It was the details embedded in the plot that contributed to the authenticity of the whole. For the art of a poet or a painter is to bring reality close to the reader or viewer through attention to detail.

Diderot often chose the form of dialogue as a means of expressing his thoughts, and he was also – and not only as one of the most important art reviewers of his time – highly endowed with a sense for the scenic and the gestural. He wrote several dramas, which are hardly performed today because of their uneventful plot with little interest in probability, but which were successful in their time thanks to their vivid portrayal of contradictory feelings and inner conflicts as well as thanks to their closeness to reality expressed through the bourgeois subjects.

Diderot”s best-known “drames bourgeois” were Le Fils naturel ou Les épreuvres de la vertu (“The Natural Son,” 1757), which had its world premiere at the Duke d”Ayen”s estate in Saint-Germain-en-Laye in the year of publication, and Le Père de famille (“The Family Father,” 1758), which was first performed in Marseille in 1760 and then for the first time in Paris by the Comédiens français on February 18, 1761. Both dramas are characterized by bourgeois family conflicts: In Le Fils naturel, a young man virtuously struggles to leave to his friend the woman with whom he has fallen in love against his will and who, in turn, is magically attracted to him but ultimately turns out to be his half-sister. In Le Père de famille, a father who actually seeks only a suitable conventional marriage for his two children allows them, after long inner conflicts, the love marriages they desire, which subsequently prove to be socially acceptable. Even more important than the plays were the essays on drama theory that Diderot appended to his two dramas, Entretiens sur le fils naturel as an epilogue to the drama mentioned in the title and De la poésie dramatique as a supplement to Père de famille. They also theoretically established the new genre as a drame bourgeois (“bourgeois tragedy”) outside the traditional genres of tragedy and comedy, better than those to represent the reality of the era and, of course, to use prose rather than verse.

The conservative-royalist publicist Élie Catherine Fréron was one of the contemporaries who tried to attack Diderot with partly dishonest means. For example, he accused him of plagiarism of some of his plays and produced or better constructed ”evidence” for this.

Diderot”s theory of theater

Diderot became significant for the development of theater (Parisian fairground theater, Comédie-Française) less through the performance of the dramas themselves – which hardly got off the ground in France – than through his theoretical work, in which he strove to renew contemporary drama.

In 18th-century French drama, courtly themes and productions dominated. Diderot, on the other hand, wanted to write for the emancipating bourgeoisie and therefore endeavored to establish a bourgeois tragedy as a new theater genre, which he also called genre sérieux. The theater was to deal with themes as they occurred in everyday life, and to take as its starting point the ordinary, as it were ”private” feelings of the people, in order to achieve a renewal of dramatic art. The drame sérieux thus led, in a sense, to the dissolution of the strict genre boundaries between comedy and tragedy. However, Diderot did not resort to an addition of extremes to overcome the separation of genres into tragedy and comedy: His plays dispensed with both pronounced comic elements and the declamatory pathos of the tragédie. Likewise, the servant roles were omitted as reminders of that difference in status that separated the two genres by necessity during the Ancien Régime (Ständeklausel). He placed the dramatic form he proposed between the classicist play (comédie classique) and the comedy, which he in turn differentiated into a serious (comédie sérieuse) and a funny comedy (comédie gaie).

Diderot demands that the poet should not raise his own voice, neither in the drama nor in the dialogues of the novels; rather, he should give the characters a language and expression appropriate to their character and situation. A moving theater, according to Diderot, lives less from the spoken word than from mimic expression; it must be in prose, since in everyday life no one speaks in verse. At the same time, the social role and function of the characters – including their bourgeois professional life – were to be more strongly incorporated into the stage work. Diderot was thus more indebted to the work of the English playwright George Lillo (1691-1739) than to Shakespeare”s theater.

A central theme of French acting theory in the 18th century was the question of sensibilité: to what extent should the actor empathize with the feelings of the character to be portrayed, i.e. follow the principle of “emotional acting”? Here, the acting performance was measured by the necessary sensibility. Diderot also initially followed this view of acting in his earlier writings.

In 1764, the English actor and friend of d”Holbach David Garrick was in Paris for a guest performance. In the years from 1769 to 1770, Fabio Antonio Sticotti (1676-1741) published his Garrick, ou les acteurs anglois. Diderot”s review of the French edition, “Observations on the little book entitled Garrick, or the English Actors” (Observations sur une brochure intitulée: Garrick, ou, Les acteurs anglais, 1770) shows a changed view. He had already stated it in a letter to Melchior Grimm of November 14, 1769: There was a beautiful paradox, he said – it was sensibility (sensibilité) that produced a mediocre actor, but more so extreme sensibility that produced a narrow-minded actor, and only cold sense and head that made a great mime. Diderot became a proponent of the theory that an actor should consciously keep his distance from the character to be portrayed, that is, follow the principle of “reflective acting.”

In the dialogue Paradoxe sur le comédien (“The Paradox of the Actor”), which he wrote from 1770 to 1773, he distanced himself entirely from emotionality. He advocated a rational, cool and observant actor; not the passionately emotional actor, but the inwardly sober one moved the minds. The perfect actor therefore embodies the following paradoxes.

For Diderot, a successful play is not created by the actor acting on stage identifying himself with his respective role and expressing his “real feeling”. For then, firstly, he could only play himself or at least a very limited range of roles and situations, and secondly, this would not even be effective on stage. Rather, the actor must decide and perform with cool detachment whatever course of action appears to him to be the most appropriate. For example, Diderot opposed so-called speaking aside; rather, an actor must not fall out of character and break the fourth wall, for example, by responding to expressions of applause or displeasure from the audience.

This incidentally ensures the reproducibility of the play, which is not the case with emotional, identifying acting. Diderot distinguishes three types of actors:

A good actor must have good judgment, be a cool observer, gifted with a keen intellect and without sensibility, and capable of imitation. For Diderot, an actor should acquire his role through imagination and judgment; he called it creating a modèle ideale that, rehearsed, could be reproduced at any time. Modern interprets a psycho-physical content of imagination, a model to which the actor has accommodated himself and which he can reproduce from memory by means of physical effort. Diderot warns the actor against the great fluctuations of emotion that prevent the actor from the mental and physical concentration that he absolutely needs for the unified construction of his role-play.

Diderot”s criticism was directed against the performance practice of classical French tragedy (tragédie classique française), because instead of stylized scenery on a small stage, he wanted a large stage that would allow simultaneous scenes to be presented. Also, instead of a local uniformity in the entire stage play, a change of location should be aimed at, which should be convincingly made recognizable in the change of the stage design.

In this respect, Diderot”s influence on theater theory reaches as far as Bertolt Brecht and his theory of alienation, which essentially served to make visible a distance between what is portrayed and what is portrayed (see also drama theory).

Journalistic activities

In the course of his literary life, Diderot participated in various journalistic projects. The press appeared in France as early as the 17th century, with the news paper La Gazette and the weekly Nouvelles ordinaires de divers endroits being published since 1631. In this context, the term “journal” initially refers to periodicals in general, so the journals of the 18th century were initially only literary periodicals, i.e. publications with a review character.

In 1740, Diderot wrote articles for the Mercure de France and the Observations sur les écrits modernes; in 1747, he planned, among other things, the edition of Le Persifleur together with Rousseau; in Grimm”s Correspondance littéraire, philosophique et critique, he wrote his first review on January 15, 1755, with the note Cet article est de M. Diderot, which was then typical for him here. In 1775, Grimm”s secretary of many years, Jacques-Henri Meister, took over the editorship of this publication. This also relieved Diderot, who in the fifties and sixties had delivered four to five contributions per year – mostly smaller or larger commissioned works of literary and art critical content. Diderot”s frequent participation in the absence of Grimm is conspicuous.

Reflections on music or his position in the Buffonist controversy

On August 1, 1752, an Italian opera company led by Eustachio Bandini performed Giovanni Battista Pergolesi”s opera La serva padrona at the Académie royale de musique in Paris. Grimm sparked a controversy that was to become known as the Buffonist Controversy.

This escalation had a decades-long tradition and manifested itself in the competition between French and Italian opera companies. In the course of the disputes, which lasted almost two years, quite a few writings were published on the subject by mostly leading music theorists and philosophers. As early as the 17th century, the distinction between dessin, the drawing or melody, as opposed to couleur, the color or chords, was important in music. In the 18th century, this pair of terms, dessin and couleur, was taken up for musical aesthetics, especially by Jean-Jacques Rousseau. It was a time when imitation de la nature, imitation, rather than the artistic idea, determined the rank and value of a work of art. And in these chords or harmonies Rousseau saw the old, the outdated, which was pleasing to the ears but without life and soul. According to Rousseau, these were based solely on conventions, for the exact understanding of which one would actually need a dictionary or an exact compositional specification from Rameau. The Italian music was to be seen by its melody, which integrated the singing and reached the human feeling, in contrast to the mathematical differentiation of the Rameau compositions, for which the harmonic structures were more important and appealed more to the intellect than to the feeling.

The question of which genre of opera should be preferred, the Italian opera buffa or the traditional French tragédie lyrique, was discussed superficially. The most prominent representative of French opera was Jean-Philippe Rameau, the composer and music theorist who, around 1722, took up arms against the music and compositional practice of the late Jean-Baptiste Lully. Rameau composed according to harmonic laws Traité de l”Harmonie (1722), based on the order of mathematics. However, he became increasingly associated with the musical sensibilities of the ancien régime in the mid-18th century, after initial support from some encyclopedists. These encyclopedists initially defended Rameau against Lully, but in 1752 positioned themselves against Rameau and Lully. Rameau”s compositional background also remained rooted in 17th century and Cartesian thought, with his aesthetic based on the principle of imitating nature.

Nevertheless, Diderot did not so much attack French opera per se as its dogmatic proponents. And so Diderot took only a middle position in this dispute, and some of his views on it were not published in time. It may be that he had his Encyclopédie project in mind, which he also wanted to win Rameau to collaborate on, it may be that the points were too pointed for him, the considerations, for example, to make the stage sets of the operas less pompous and to adapt them to everyday life, met with his unqualified approval. All in all, the Buffonist controversy played only a subordinate role for him. Ultimately, Diderot advocated new subjects in music that would give it the opportunity to arouse genuine passions.

Diderot was very interested in music; through harpsichord lessons for his daughter, for example, he met the music theorist and author Anton Bemetzrieder in 1769.

Diderot”s world of thoughts

If we look at Diderot”s work as a whole, he never arranges his thoughts into a unified and comprehensive system (“coherently systematizing philosophical system”), nevertheless a fixed system of reference can be found or can be reconstructed. But the reflections spread over his entire œuvre give the impression of the inconsistent up to the contradictory, paradoxical in his assumptions.In this Diderot”s peculiarity of the variety of appearances, the frequent solution in the dialogue form shows up. Diderot”s thinking and reflecting is directed to one aspect, which he now, however, does not systematically work through in relation to his entire work, but rather he penetrates the current aspect without consideration of the philosophical whole. Furthermore, Diderot rarely provides sources, and his references are no longer directly accessible to the recent reader, so that his roots in the humanities are only indirectly revealed. The analysis of Diderot”s philosophical-historical facts of his œuvre are complicated by his only incompletely preserved correspondence and the equally fragmentary evidence of his library, which was exported to Russia and disseminated there; its accompanying catalog, moreover, was lost.

This may be due to the fact that Diderot rejected dogmatic thinking in any form. Such a consequent rejection of a system spirit may be based on his view that all metaphysical systems, no matter how elaborated, do not allow to grasp an absolute truth or the essence of things. For Diderot, dogmatism is an expression of intellectual limitation and reflexive one-sidedness, since such attitudes absolutize the fullness of the complexity of reality and permit only a limited form of reconstructible reality. This shows his epistemological and metaphysical skepticism.

The lack of an immediately coherent and systematizing philosophical system does not mean, however, that Diderot was not able to solve questions in his writings by a unified, systematic and logical structure. As examples for such an exclusive procedure, the following works are mentioned Mémoires sur différents sujets de mathématique (1748), Éléments de physiologie (1773-1774) or the article Beau from the Encyclopédie. Thus, a claim that Diderot”s works were characterized by a fundamental inability to think methodically can by no means be confirmed. Rather, he solved complex philosophical questions in various literary genres.

He assumed in the human cognition that the material things acted on the senses and thereby caused a perception in the human mind. With those perceptions the mind, entendement, was concerned, corresponding to the main ability of the human mind to deal with the mémoire, raison and imagination. These, however, also determined the basic structure of the sciences and arts in human cognition; for example, history included memory, mémoire, as its foundation, philosophy based on reason, raison, and poetry arising from imagination, imagination.

According to Diderot, the “techniques of cognition” as important procedures lead to human cognition. From collected experiences (observations), i.e. the material things which have an effect on the senses, the contents of experience become hypotheses (reflection) by a selective compilation or recombination, the value of which is confirmed or negated by testing (experiment). Therefore, one reaches the truth only if the contents of perception come from the senses to the reflection and via the reflection and the experiment again to the senses.

Diderot developed his world of thought in various literary forms and genres he preferred, such as the sketch, the essay, the dialogue, the dream, the paradox, the letter, and finally the conte.

The meaning of the term sensibilité universelle in the reflections of Denis Diderot

Diderot was influenced by the discourse of turning away from Cartesian thinking and turning towards English-style empiricism, which became more and more apparent in the 18th century. At the same time, the notion of human sensibility experienced an important significance as an explanation of interpersonal processes; thus, one spoke of a feeling sensibility, sensibilité de l”âme, on the one hand, and on the other hand, of an internalized moral sensibility that was linked to prevailing values. This understanding of sensibility was incorporated into medical discourse throughout the century and interpreted as a property of the irritable nervous system. But vitalist ideas, such as the Doctrine médicale de l”École de Montpellier, also influenced Diderot in ways similar to his intellectual proximity to Shaftesbury. It was the Pensées sur l”interprétation de la nature (1751) that had led Diderot to his first work on natural science. In this monograph, he included a critical appraisal of the philosophical positions of Pierre-Louis Moreau de Maupertuis. That Maupertuis, who in his Système de la nature ou Essai sur les corps organisés – first published in 1751 in Latin as Dissertatio inauguralis metaphysica de universali naturae systemate and under the pseudonym Dr. Baumann – had dealt with Leibniz”s monad theory and its significance for natural philosophy. Maupertuis had also attributed a sensibilité, so to speak, to the molecules of matter in order to explain a movement and development to organic life.

Already in 1759, Diderot wrote a letter to Sophie Volland, in which he reported that he had discussed this at the Château du Grand Val with d”Holbach and the Scottish-born “father Hoop”, le père Hoop, a studied physician Also the articles about the animal, animal, and the birth, naître, circled this complex of topics. He had sketched this idea of a “sensible matter,” or a universal sensibility, sensibilité universelle, between 1754 and 1765, more precisely in another letter this time to Charles Pinot Duclos dated October 10, 1765. It was exactly this sensibilité générale de la matière or sensibilité universelle, which makes inorganic become organic and which was the basic hypothesis of the Diderotian understanding of nature. Life arises from the successive combination by the “molecules” of matter capable of sensibility, similar to a swarm of bees. In Diderot”s philosophy of nature, the universe consists of sensitive and energetic “molecules” which can recombine and, as it were, dissolve again through their inherent powers. A continuous change is the consequence of this.

In 1769, Diderot wrote Le rêve de D”Alembert and dealt with the question of the transition from inanimate, inorganic matter to animate, organic matter with the concept of sensibilité. In the section of Entretien entre d”Alembert et Diderot of Le rêve de D”Alembert (1769), he first reflects on the concept of “motion”. This, he argues, is not to be understood as (physical) motion in the narrow sense, i.e., the transport of a body from one place to another, but is a property of the body itself. Then, in the further dialogue, he comes to speak about the unity of matter and sensibility, sensibilité générale de la matière or also sensibilité universelle, and uses an analogy from physics for this. Thus he compares the living force, force vive, with the dead force, force morte. Whereby the living force would have the modern physical meaning of work or kinetic energy, while the concept of the dead force would be attributed to potential energy. This against the background that the difference between mechanical force and energy was not yet clearly conceptually differentiated in the 18th century. To these two forces would correspond, as it were analogously, the sensibilité inerte and the sensibilité active. In the inorganic world, sensibility is only potentially contained as sensibilité inerte, but it carries the possibility of its development. Thus, the emergence of the living world is conditioned by the release of the potential forces contained in matter itself, the sensibilité active.

His “matter” is thought in Diderotian “molecules” sometimes also as “atoms”, which however carry an indispensable quality so to speak immanently in themselves, namely that of the “sensibility”, sensibilité. Both are the guarantors for the development or development dynamics. Whereby “sensibility” only set in with a certain level of organization. As such, these Diderotian “molecules” have partly properties, which already carry their precursors in themselves and which they get from them, as it were; besides, “resulting” properties or also new properties, which the precursors did not have yet and which only emerge from the interaction of the elements, “emerge”, so that one could call the Diderotian conception of “matter”, or his concept of materialism also “emergetic monism”.

Diderot”s views on biological thought

Denis Diderot was very interested in biological questions. These questions revolved around the themes of the origin of matter and its transition from the inorganic world to organic, living forms, the emergence of species in time, the questions of primordial generation and preexisting germs, and the like, as in Le rêve de D”Alembert (1769), De l”interprétation de la nature (1754), and Éléments de physiologie (1773-1774). Diderot read, met, or was in intellectual exchange with Paul Henri Thiry d”Holbach, Georges-Louis Leclerc de Buffon, Théophile de Bordeu, Pierre-Louis Moreau de Maupertuis, Albrecht von Haller, Abraham Trembley, John Turberville Needham, Marie Marguerite Bihéron, and other contemporaries.

In his biological thinking, Diderot was committed to the idea of transformation. Notions of a “Scala Naturae,” a “stepladder of nature” (French: l”échelle de la nature) also shaped Diderot”s thinking.According to their assumptions, there were no breaks in nature, all natural objects were in a close continuous relationship to each other.His assumption of the sensibilité générale de la matière gave him the opportunity to explain the emergence of life through the release of the forces potentially contained in matter, the force morte and the force vive. In the Letter on the Blind for the Use of the Sighted (1749), he argued that although nature could form itself from its inherent forces, only those forms remained that were viable and whose structure did not contradict their environment. These thoughts remind of the evolution theory of Charles Darwin. However, the thought of the natural selection is still missing. It seems to be closer to Jean-Baptiste de Lamarck, who was to present the first scientific theory of evolution around 1800.

Diderot”s concept of matter contains, so to speak, the unity of matter and sensibility. To explain this, he uses an analogy from physics. Thus, in Le rêve de D”Alembert, he compares the living force with the dead force (force vive and force morte), whereby the living force roughly corresponds to the modern physical concept of work or kinetic energy, whereas the dead force corresponds to potential energy.

This “matter” is attributed with the same immanence the possibility of development and progression to independent formations. In Diderot”s opinion, the prerequisite for this was that it was assumed to have “sensibility”; in doing so, he differentiates between inactive and active sensibility. “Matter” was the whole consisting of individual “molecules”, sometimes Diderot also spoke of “atoms”, which then united in infinite variety to bodies or components, also to living organisms. These building blocks combine to a whole, to a coherent whole, which has the potential to living organisms and the development of consciousness. Thus, being is explained as a combination of “sensitive molecules”. Thus, the transition from the inorganic to the organic and ultimately to the living becomes a continuum.

For Diderot the living and thus also the human being is part of the causally conditioned universe, and in it a highly complex, structured connection of “molecules”, which is no longer decisively distinguished from the rest of the living being by its reason, by postulated innate ideas (ideae innatae according to Cartesian innatism), or an immaterial soul. Life differs only more gradually in its “molecular” complexity. A conception that seems to be more influenced by his participation in the lectures of Guillaume-François Rouelle than by the conception of de Buffon, which still attributes to man an exceptional status in the chaîne des êtres.

In the very letter to Sophie Volland, which Diderot wrote from Grand-Val on October 15, 1759, he clearly said that a being could never pass from the state of being non-living to the state of being living. For a “matter” conceived exclusively in physical and chemical terms, a transition from inorganic “molecules” into organic life was inconceivable. According to Diderot, no combination of inorganic “molecules”, no matter how complex, would be capable of this for such an interpretation of “matter”. But by including, by supplementing a purely physical-chemical concept of matter by the postulate of a sensibilité universelle (Diderot”s own concept of matter), inorganic, dead, can develop into living and conscious life.

The effect of the inner agent, the énergie, reminds of Gottfried Wilhelm Leibniz, whose accessible works he appreciated, but for Leibniz this agent was completely immaterial. Although some things are reminiscent of a vitalistic position, such as the vital force (vis vitalis), his attitude is closer to the school of Montpellier, Doctrine médicale de l”École de Montpellier, which is called “vitalistic materialism”.

For Diderot, the individual species, here using the example of the quadrupeds, have developed from a primordial animal, an archetype of all animals, nature has done nothing more than to lengthen, shorten, reshape, increase or omit certain organs of the same animal – so in the Pensées sur l”interprétation de la nature (1754). These ideas seem to have originated in exchange with or at least been influenced by the thoughts of de Maupertuis and his Système de la nature ou Essai sur les corps organisés (1751) and those of de Buffon and Louis Jean-Marie Daubenton in the fourth volume of Histoire naturelle, générale et particulière, (1752).

Development was conceived by Diderot as a succession of metamorphoses that modified the form of the original animal, in the sense of what was said above. Between these “species transitions”, clear separations or boundaries that distinguished one species from the other were not the focus of his considerations, rather the transition from one species to another was thought of as something imperceptible and gradual. For him it seemed that whole species could come into being as well as die off one after the other, just as the individuals of each of the individual species. Rejecting a conception of creation, he held not faith but natural observation or experiment to be the essential support for the assumption that species were unchanging since an assumed creation.

However, Diderot”s conception cannot be equated with the idea of evolution in the narrower sense. Although the idea of an imperceptible and gradual transition from one species to another was already a first important step towards the later idea of classification of the individual species.

Diderot witnessed three major wars in his lifetime: the War of the Polish Succession from 1733 to 1738, the War of the Austrian Succession from 1740 to 1748, and the Seven Years” War as the first global event from 1756 to 1763. In 1751, Diderot wrote the article Political Authority (“autorité politique”) for the Encyclopedia. In it, he emphatically questioned the divine right of kings and rulers as well as the natural law derivation of their authority. He did not see the solution in the Montesquieu separation of powers, but rather in a monarchy supported by the consent of the subjects, the regent acting as the executor of the will of the people. A single enlightened monarch, however, was no guarantee against despotic aspirations.

Diderot did not develop any clearly circumscribed political ideas that would have replaced a system like that of the Ancien Régime. But he formulated in general terms that no human being was allowed to rule over another human being without restriction. Rather, the subjects had to secure themselves against the ruler, and vice versa, through a social contract, consentement.

For the Physiocrats, as well as for Anne Robert Jacques Turgot, the Marquis de Condorcet and d”Alembert, economic liberalism was inseparable from the idea of political liberalism. For Abbé Galiani and Denis Diderot, however, these considerations missed the reality: a self-establishing “natural order in the economic system” would develop into a state of the propertied classes, in which the interests of individuals or groups would prevail over the concerns of the general public and the population. Diderot therefore changed not only his economic, but subsequently also his political conceptions. He finally broke with physiocratism after his trips to Bourbonne-les-Bains and Langres, where he was confronted with the misery of the peasants. In his Apologie de l”abbé Galiani ((1770), published in 1773), he once again defended the latter”s rejection of free trade in grain.

His important political texts include Voyage de Hollande (1773), Observations sur Hemsterhuis, Réfutation d”Helvétius (1774), Essai sur les règnes de Claude et de Néron (1778), Dialogues sur le commerce des blés (1770), and Histoire des deux Indes. Some texts were letters or replies, such as Première lettre d”un citoyen zélé (1748) to M.D.M. subsequently identified as Sauveur François Morand, Lettre sur le commerce des livres (1763) to Antoine de Sartine, Observations sur le Nakaz (1774), and Plan d”une université (1775), both to Catherine II of Russia. Almost all of the above works appeared in the seventies of the 18th century.

Diderot”s main political and economic writings were written between 1770 and 1774. In them, he also described his disappointments with the “enlightened monarchs,” such as Tsarina Catherine II of Russia, and even more so with Frederick II of Prussia.

Frederick II wrote to d”Alembert and Voltaire, among others, the following lines:

The reaction of the Prussian philosopher-king did not remain unanswered, Diderot wrote in 1774 the Lettre de M. Denis Diderot sur l”Examen de l”Essai sur les préjugés. Frederick II was judged by Diderot quite differentiated. Thus, in 1765, in the article Prusse in the Encyclopédie, he evaluated the literary achievements of the monarch as positive.Between Diderot and the Prussian king, however, there was quite an antipathy, not least on the part of Diderot because of the Silesian Wars (First Silesian War (1740-1742) and Second Silesian War (1744-1745)) and the longer lasting Seven Years War (from the Prussian point of view also called the Third Silesian War). Although his earlier attitude towards the Prussian monarch – Diderot had been accepted as a foreign member of the Royal Prussian Academy of Sciences in 1751 – was still a rather more positive one. Thus, according to Diderot, the Prussian king had rendered outstanding services to the renewal of the sciences, as well as the arts, and their protection.

When Diderot started his journey to the Russian tsarina in St. Petersburg from 1773 to 1774, he consistently avoided the proximity to the Prussian residences in Potsdam and Berlin, although he received several invitations from the Prussian king. For Diderot, Frederick II was a destroyer of peace; he harbored a deep dislike for the Prussian monarch and saw the Frederician state as a military state with Frederick II at its center as its tyrannical, Machiavellian despot.

Guillaume Thomas François Raynal, usually Abbé Raynal for short, published the first edition of The History of the Two Indies (“Histoire philosophique et politique des établissements et du commerce des Européens dans les deux Indes”), that is, of India or Asia (East Indies) and the Caribbean and Latin America (West Indies), in 1770. He describes how the European countries deal with their colonies and mentions the consequences of global and intercultural trade. Diderot contributed intensively to this work.

First published in 1770 – in six volumes – in the Netherlands, in Amsterdam, then in 1774 – in seven volumes – in The Hague, and in 1780 – in ten volumes – in Geneva, the constantly expanded work also became more and more consistent. It was banned as early as 1772, and the 1774 version was also immediately placed on the index by the clergy. Finally, on May 21, 1781, it was consigned to the stake following a ruling by the Paris Parlement.

Raynal was threatened with imprisonment. He fled, left France and went to Switzerland and Prussia. Diderot defended the Abbé Raynal, without hesitation and consistently against the attacks of the clergy and the administration. In this situation there was a break with Frederick Melchior Grimm, who played an inscrutable and intriguing game between Abbé Raynal, Denis Diderot and his contacts at the French court. Diderot wrote Grimm a letter on March 25, 1781, in which he disappointedly broke away from his former close friend; however, the letter did not reach the addressee.

“The History of the Two Indies” was a pamphlet against slavery, colonialism, and political paternalism and despotism, in keeping with Diderot”s views. The work was a bestseller, it had high circulation and was also reimported into France through pirated prints from surrounding foreign countries.

Diderot”s political philosophy, like his other reflections and approaches, was less systemic. The original human state (state of nature) was understood by him as a struggle for survival against the rigors of nature, for which people had to join forces, in the sense of a community, sociabilité. Justice was for him a universal concept, valid for the state of nature as well as for a developed community. In his encyclopedia article Naturrecht, droit naturel, the striving for property and profit was assumed to be a general human characteristic and thus understood as a general will. These aspirations were individually developable according to the abilities that lay in the individual human being. Diderot did not design utopian states of human coexistence. He considered a human community to be successful when religious and legal regulations neither contradict each other nor the natural needs of man. The natural needs depended on the geography, the climate, the development of civilization, and so on.

The concept of volonté générale, or general will, first appears in the texts of the French philosopher, theologian, and mathematician Antoine Arnauld, where it is placed in each case in the context of the Catholic doctrine of grace and refers to God as subject.

Diderot defines volonté générale in the article droit naturel of the Encyclopédie with the following words:

Diderot contrasts this general will with the private will of the individual, the volonté particulière. In Diderot”s view, however, the general will did not refer only to the state or the ruling political entity, but to the whole of mankind. For him, it was the only principle of order inherent in the human world and has the character of a general principle. This is another reason why he used this term in its plural form.

Reflections on the gender order

For Diderot, sexuality and gendered behavior in the sense of a science de l”homme can most readily be derived from medical and biological considerations. Thus, he paid greater attention to the influence of the genitals and their effect on female behavior in many of his literary productions, such as Les bijoux indiscrets (1748), La religieuse (1760), Le rêve de D”Alembert (1769), Supplément au Voyage de Bougainville (1772). Female life is examined in depth in Sur les femmes (1772) and in Paradoxe sur le comédien (1769).

Although Diderot in many respects colocates the ideas about femininity of his time, he clearly takes a stand against degrading disparagement or even violence toward women.He contradicts, in a sense, Antoine Léonard Thomas Qu”est-ce qu”une femme? (1772), who often stuck to gender stereotypes in his essay.

For him, women were able to feel more anger, jealousy, superstition, love and passion. But this more of emotions was in the “drive to lust” in the same distinctness less than in the man. In his work Sur les femmes (1772), Diderot saw the female orgasm, l”extrême de la volupté, as so differently shaped by the difference between her genitals and her “drive to lust” that sexual satisfaction could be expected more regularly for men. Women, on the other hand, would have to strive for it, and they would not succeed in achieving this fulfillment as naturally as their male counterparts because they had less control over their senses. Diderot assumed that women had a more delicate body and a more unstable soul.

Although Diderot did not seem to deal extensively with the questions surrounding religion, he often confronted this complex of topics in literature during his life.

In July 1766, he wrote the following lines in a letter to the engineer Guillaume Viallet (1728-1771), Ingénieur ordinaire des Ponts et Chausséese a friend of Charles Pinot Duclos:

In a letter to Tsarina Catherine II. (1774) he wrote:

Late philosophical works

Among Diderot”s most important philosophical works is D”Alembert”s Dream (Le Rêve de D”Alembert) of 1769. Here, in the form of a dialogue, he sets forth his materialist positions, considers the sensibility of matter, differentiates this sensibility, and attempts to describe the evolution of living matter.

An important writing is the essay Principes philosophiques sur la matière et le mouvement (“Philosophical Principles on Matter and Motion”), published in 1770 and only a few pages long.

Between 1773 and 1774, Diderot wrote the Éléments de physiologie. Although the work takes the form of an aphorism-like collection and contains mainly notes, paraphrases, explanations, comments, and reflections on medical-anatomical-physiological topics, it has partly the character of a textbook, partly that of a methodical reflection on the nature of living matter. The form suggests that it is a work in progress. To improve his knowledge of human anatomy, Diderot attended one of Marie Marguerite Bihéron”s weekly anatomy lessons with the modeler of anatomical wax preparations. He read many contemporary anatomical, physiological, medical, and anthropological writings around 1774, including Elementa physiologiae corporis humanivon Albrecht von Haller (1757-1766), Medicine de l”Esprit (1753) by the French surgeon Antoine Le Camus, and Nouveaux éléments de la science de l”homme (1773)by Paul Joseph Barthez.

An important milestone in Diderot research was the discovery of previously unknown material in 1948 by Herbert Dieckmann. It was presented in 1951 under the title Inventaire du fonds Vandeul et inédits de Diderot. After the last direct descendant of Diderot, Charles Denis also Albert Caroillon de Vandeul (1837-1911), propriétaire d”Orquevaux, had died in 1911, the estate of Denis Diderot had passed to the house of Le Vavasseur. Dieckmann found this estate of Baron Jacques Le Vavasseur at the Château des Ifs (Département Seine-Maritime). It originally belonged to the collection of Diderot”s daughter Marie-Angélique de Vandeul. With this work, Dieckmann laid the foundation for a new complete and critical Diderot edition, the Œuvres complètes of 1975. The editorial work was not undertaken by Dieckmann alone; rather, he received significant support from Jean Fabre, Jacques Proust, and Jean Varloot.

A large number of Diderot”s texts can be found in the Correspondance littéraire, philosophique et critique, which was circulated exclusively in manuscript at various European courts from 1753 onward. An important step in the exploration of this extensive textual material was made by Bernard Bray, Jochen Schlobach, and Jean Varloot in a colloquium and anthology (La Correspondance littéraire de Grimm et Meister (1754-1813). Actes du Colloque de Sarrebruck, 1976) or also by Ulla Kölving and Jeanne Carriat (1928-1983) with their Inventaire de la Correspondance litteraire de Grimm et de Meister from 1984.

Early reception and assessment in France

Diderot had a negative nimbus in post-revolutionary France. The author and critic Jean-François de La Harpe, who was involved in the French Enlightenment, was decisive in this regard. Although he posthumously defended Diderot against attacks in the Mercure de France, in later times he accused him of moral corruption and disparagingly with negative connotations of atheism and materialism. His distorting and negative judgment subsequently entered French, as well as English and German literary reviews and histories of philosophy.

The French man of letters Eusèbe de Salverte (1771-1839) wrote Éloge philosophique de Denis Diderot (1801) during the Napoleonic era. The encyclopedist and man of letters Jean-François Marmontel found many words of praise for Denis Diderot in his posthumously published Mémoires d”un Père pour servir à l”instruction de ses enfants (1805). The French theologian, church historian and man of letters Michel Pierre Joseph Picot (1770-1841) wrote – in the eleventh volume of the Biographie universelle ancienne et moderne (1811-1828) of the brothers Louis Gabriel and Joseph François Michaud – from 1814 a biographical essay about Diderot.

It was Charles-Augustin Sainte-Beuve who, in his Portraits littéraires (1844), not only portrayed Denis Diderot as a creative writer, but also emphasized his important role within the French Enlightenment. He was probably the most consistent philosophical thinker against the Ancien Régime, although not explicitly political in his conceptions of thought, he was nevertheless the real voice in philosophy of this century in transition. He was the leader of all those undisciplined thinkers who rebelled against the existing order, the bond between Voltaire, d”Holbach, Buffon, Rousseau, and others, and between the natural scientists and the aesthetes, the literati and the visual artists. In his criticism, however, Sainte-Beuve also joined the opinion held by conservative literary critics in France that Diderot was the most “German” of the French philosophes. This was a view that he propagated and that was later to shape the history of reception in the German-speaking world.

In addition to his writings, Diderot became known in Germany through his contacts with German travelers, for example on their Grand Tour, often mediated by the German-born Grimm and d”Holbach. Among them were noblemen, artists and scientists, e.g. Ferdinand of Brunswick-Wolfenbüttel in 1767, Ernst II of Saxe-Gotha-Altenburg in 1768 and Karl Heinrich von Gleichen-Rußwurm (1733-1807).

In the German-speaking world, Diderot”s importance, in the sense of a cultural transfer, was recognized earlier than in France. Thus Goethe was interested in the narrative work, Lessing in the theater productions, Hegel and Marx in the philosophical reflections, and finally Hofmannsthal in Diderot”s correspondence with Sophie Volland.

In May 1769, Kant”s student Johann Gottfried Herder embarked on a journey to France, first by ship to Nantes and later to Paris. There it was the above-mentioned Johann Georg Wille, engraver and former neighbor of Diderot, who introduced Herder to Parisian society. And so Herder also met Denis Diderot. In 1769 he started his return journey to Hamburg via Belgium, Amsterdam. Inspired by Immanuel Kant and Diderot, Herder adopted the concept of energy in his considerations of aesthetic perception.

Johann Wolfgang von Goethe held his colleague, thirty-six years his senior, in high esteem and saw in him a kindred spirit of the Sturm und Drang. He had received French lessons from 1758 and was later well acquainted with the French language and culture. Between 1759 and 1761 he saw Le Père de famille (1758) at the French theater in Frankfurt am Main and Le Fils naturel (1757). He read Les deux amis de Bourbonne (1770) and later, in Weimar, Diderot”s philosophical and aesthetic writings. In March 1780 and 1781, respectively, he tackled the novels Jacques le fataliste et son maître (1776) and La religieuse (1760), not yet published in France. He also knew the novel Les bijoux indiscrets (1748).

The first, albeit quite free, partial translation from Jacques der Fatalist und sein Herr (Jacques le fataliste et son maître) was the episode about Mme de La Pommeraye, transcribed by Friedrich Schiller and published in 1785 under the title Merkwürdiges Beispiel einer weiblichen Rache (Strange Example of Female Revenge) in the first and only number of his journal Thalia. An anonymous retranslation into French of this Schiller text was printed in Paris in 1793. In 1792, a two-volume translation by Wilhelm Christhelf Sigmund Mylius appeared under the title Jakob und sein Herr from Diderot”s unprinted estate, published by Johann Friedrich Unger in Berlin. In a letter of February 12, 1788 to Christian Gottfried Körner, Schiller wrote: “What activity was in this man! A flame that never went out! How much more he was to others than to himself! Everything about him was soul! (…) Everything bears the stamp of a higher excellence, of which the highest effort of other ordinary earthlings is not capable.”

Frederick Maximilian Klinger arrived in Petersburg in 1780 as an orderly officer with the rank of lieutenant in the naval battalion of the Russian heir to the throne, Grand Duke Paul I. He was a member of Diderot”s family. After Diderot”s death, his library was transferred to the tsar”s court, including the manuscript of Le Neveu de Rameau, previously unpublished in France, which Klinger found in Diderot”s library and first offered as a copy to the publisher Johann Friedrich Hartknoch in Riga, who, however, refused. Finally, around 1801, the copy was given to Friedrich Schiller, who in turn gave it to Goethe, who translated and published it. It appeared in Leipzig with the title Rameau”s Nephew, a Dialogue by Diderot. Curiously, in 1821 Goethe”s translation was retranslated into French by two French literati, Joseph Henri de Saur and M. de Saint-Geniès, published in 1821, and also passed off as the original. It was not until two years later that an authentic edition was made from a copy by Mme de Vandeul.

The structures of thought that Diderot spread out in his Le Neveu de Rameau and also Jacques le fataliste et son maître showed in many respects a kinship to the Phenomenology of Spirit published by Georg Wilhelm Friedrich Hegel in 1807. It is not surprising, then, that Hegel was familiar with some of the works of the French Enlightenment. In the sixth chapter of his Phenomenology (Section B. The Spirit Alienating Itself. Bildung and a. Bildung and its Realm of Reality), he made explicit reference to Le Neveu de Rameau. Hegel, analyzing the “modes of appearance of the spirit,” outlined a connection between “education” and the “alienating spirit.” In Diderot”s dialogue, two modes of consciousness of the spirit would be expressed, the narrator”s I on the level of simple, not yet reflected consciousness, and the nephew”s mode of manifestation of the spirit, which, within the framework of Hegel”s dialectic, was already on a higher level. While the first-person narrator mostly reflects the positions of society without reflection in his remarks, the consciousness of the nephew reflects itself precisely in relation to society and observes itself critically in this. He is able to do this by means of his education, by reasoning and reflecting on music, pedagogy and the like. Hegel elevated Diderot”s dialogue of first-person narrator and nephew to an abstract level of dialectical development, the development of the manifestations of the spirit. For Diderot, on the other hand, the focus was on the personalities and their disjuncture of character.

In contrast, Immanuel Kant made no reference to Diderot”s writings in his work. In the Academy Edition of the Collected Works, edited by Gottfried Martin, only one mention of Diderot and D”Alembert is documented. The remark comes from a letter written by Johann Georg Hamann to Immanuel Kant in 1759.

Hermann Julius Theodor Hettner dealt with the contents of the Encyclopédie in an account in History of French Literature in the Eighteenth Century (1860). Johann Karl Friedrich Rosenkranz was the first to write a comprehensive biography, Diderot”s Leben und Werke (1866), about the French philosopher, encyclopedist, and author in German.

Friedrich Albert Lange, in his 1866 work Geschichte des Materialismus und Kritik seiner Bedeutung in der Gegenwart (History of Materialism and Criticism of its Significance in the Present), gave Diderot room for his own interpretations on several occasions. Lange takes over the view of Rosenkranz, who attested Diderot a contradictory character and a fragmented literary activity with basically igniting genius of his nature in luminous features. Lange sees in Diderot not only none, but everything else than a materialist, who, however, in the exchange with his contemporaries further developed to such a one, while he had been merely inspiring for other philosophers with his conception of materialism.

Wolfgang Engler assumed that Diderot himself represented the (bourgeois) utopia of true humanity that his drama The Natural Son exposed. In deliberate contrast to courtly conversation, in which language was falsehood par excellence and served intrigue and egotism, he saw at the origin of sincere communication “the problem of stating something without making the statement.” The “principle of sincerity” polemicized “against a mode of communication based on the contradiction between understanding (communication) and motivation (interest).” Whoever speaks or writes exposes himself to the suspicion of intending something, and thus to that of unfairness. “To prevent the silencing of sincerity in the case of radical suspicion of motive, only the solitary and involuntary statement is able”. In his 1769 text Le Rêve de D”Alembert, Diderot has the title character speak in fever sleep. “The feat of stating something without wanting anything and consciously meaning it was accomplished” and thus – as if by a magic trick – unquestionably the truth was told.

It was Thomas Carlyle who dealt extensively with Denis Diderot. His first English-language biographer was John Morley; he wrote an account of Diderot”s life Diderot and the Encyclopædists in 1875.

Further interpreters are Ernst Cassirer (Die Philosophie der Aufklärung, 1932) and Henri Lefebvre, who made Diderot more present again in the French-speaking world in 1949. Werner Krauss, with his scholarly focus on the French Enlightenment, also appreciatively included Diderot in the overall context of the European Enlightenment. In Russia and then in the Soviet Union, Diderot”s interpretations and interpretations found their way into the discussion of dialectical materialism, for example with Georgi Valentinovich Plekhanov”s writing Contributions to the History of Materialism (1896), or in the introduction to Lenin”s Materialism and Empiriocriticism (1908), in which he compares the philosophies of George Berkeley and Diderot.

Éric-Emmanuel Schmitt wrote a comedy about Diderot”s erotic adventures and the encyclopedia under the title Le libertin (Engl. title: The Free Spirit). The premiere took place in Paris in 1997, followed by the first German-language performance in the same year. The play was adapted by Schmitt into a screenplay of the same name, which was filmed by Gabriel Aghion as Liebeslust und Freiheit (Le libertin) and released in French cinemas in 2000.

In 1979 a lunar crater and in 1994 the asteroid (5351) Diderot were named after Diderot.

Wikisource: Lettres à Sophie Volland. Sources and full texts (French)



  1. Denis Diderot
  2. Denis Diderot