Diderot’s first independent work, consisting of sixty-two short reflections on Christianity, deism, sceptism and atheism, appeared anonymously. It made a considerable impact and was condemned to be burnt by the Paris Parlement, as “presenting to restless and reckless spirits the venom of the most criminal opinions.” Of all of Diderot’s works it was the one that went through most editions in the eighteenth century

In the opening paragraph Diderot writes: “People ceaselessly proclaim against the passions . . . people inpute to the passsions all of men’s pains, and forget that they are also the source of all his pleasures. It is an element of man’s constitution of which we can say neither too many favorable, nor too many unfavorable things. But what makes me angry is that the passions are never regarded from any but the critical angle. People think they do reason an injury if they say a word in favor of its rivals. Yet it is only the passions, and the great passions, that can raise the soul to great things.”

Completed but not published, an allegory which takes the form of a discussion between a small group of philosophers as they walk through an avenue of thorns, which represents Christianity, an avenue of chestnut trees, where the philosophers feel at ease, and an avenue of flowers, which represents unthinking hedonism.

“(Only) two matters deserve my attention and they are precisely the ones you forbid me to discuss.

Impose on me silence concerning religion and government, and I’ll have nothing more to say.”

Diderot’s first novel, published anonymously, has been seen as being pre-Freudian. It was composed for his lover Madeleine de Puisieux after he informed her that writing a novel was easy.

The plot centres on a magic ring which can make women’s vaginas (the jewels of the title) speak: while a woman may say one thing, her sex may say another, and what her sex has experienced may be not at all what the woman wants (or can allow herself) to admit. Is the world such that “isn’t it true that we are only puppets?”

Although published anonymously in June and distributed clandestinely word quickly spread as to its author. It made a considerable impact and prompted Voltaire to write to Diderot asking the honour of his acquaintance. He told Diderot he desired “passionately” to talk to him, “whether you think yourself one of his (God’s) works or whether you regard yourself as necessarily-organised portion of an eternal and necessary matter. Whichever it be, you are a truly estimable part of that great Whole which is beyond my understanding”. The publication of the Lettre led to Diderot’s arrest and imprisonment at Vincennes between August and November.

The Lettre is an elaboration of sensualist epistomology, postulating that all thought is the product of the senses and concludes that if a blind man’s knowledge of the world is limited by his sightlessness, so ours is bounded by the handicap of having only five senses: if we had a hundred, what else might we know? Diderot rejects Condillac’s view that the mind is passive: “it is not enough that objects strike us, we must in addition pay attention to the impression they made on us”. “How does a man born blind form ideas of shapes?”

“If you want me to believe in God you must make me touch him”.

The Prospectusfor the Encyclopédie was published in October.

“Let posterity say when opening our dictionary: such was then the state of the sciences and fine arts.  Let them add their discoveries to those we have catalogued and let the history of the human mind and its productions go from age to age until the most far-off centuries...Let us do for the centuries to come that which we are sorry the past centuries did not do for us...”

This short work, published in February, on language and aesthetics formed a companion volume to the Letter on the Blind of 1749. A few weeks later, Diderot published a second edition, containing some “additions” in answer to objections raised by a woman friend of his named Mlle de la Chaux. The story of this young woman, translator of David Hume, is told in Diderot’s This Is Not a Story. She died in 1755. Her translation of various essays by Hume appeared under the title Essais sur le commerce, le luxe, l’argent, (Amsterdam, 1752-3).

Second volume published in January.

(CHA-CON), vol III, published in November.

The Penseesappeared in January and was a revised version of De l’interpretation de la nature, which was published in November 1753. It consists of fifty-eight reflections, conjectures and questions concerning scientific method and specific scientific problems, in addition to an attack on the overweening pretensions of mathematics which was to open a rift between Diderot and d’Alembert. It was meant to be a theoretical supplement to the Encyclopédia.

Diderot, ‘Droit naturel’, article in Volume Five of the Encyclopédie, published in November.

“It is evident that if man is not free...there will be neither moral good or evil, neither just nor unjust, neither obligation nor right.”

Landois, a little-known playright, sent Diderot a manuscript on morality and Diderot wrote a reply, in which he outlined the basic principles of his philosophy. It was published in the Correspondance littéraire, 1 July.

Volume VII of the Encyclopédia appeared in October. It included d’Alembert’s article ‘Genèva’. Written after d’Alembert visited Voltaire at Les Délices in August 1756, it enraged Genevan authorities with its suggestion that they abandon their opposition to the theatre and allow dramatic presentations to educate their sensibilities. It also caused considerable comment with its unwelcome praise of the Genevan pastors for their learning, morals and advance views and for the fact that “some of them no longer believe in the divinity of Jesus Christ”. The Genevan government appointed a committee under the chairmanship of Voltaire’s friend and physician to refute d’Alembert’s description of their religious views and practices.

Both Diderot and, later Rousseau, thought that Voltaire was responsible for the remarks on the theatre; it was well known that the Genevan authorities had tried to prevent Voltaire from staging private theatricals on their territory.

This play was published together with its theoretical supplement, Entretiens sur Fils naturel. The Entretiens consists of three discussions about the play between Diderot and Dorval, the leading character. The play itself, subtitled, The trials of virtue, centres on the conflict between friendship and love experienced by Dorval.

Act IV, scene 3 contains the line which, following his self-imposed isolation, infuriated Rousseau,: “Interrogate your heart: it will tell you that the good man is in society, and that only the bad man is alone”.

“Certainly there are still barbarians. When won’t there be? But the time of barbarism is past. The century has become enlightened. Reason has grown refined, and the nation’s books are filled with its precepts. The books that inspire benevolence in men are practically the only ones read.”

This play was published in November together with its theoretical supplement, Discours sur la poesie dramatique. It played successfully in several French cities and in Baden and Hamburg, but when it reached the Parisian stage in February 1761, it ran for only six performances. In the essay Diderot expounded his programme for a new drama: a theatre or truth and Nature, related, in its use of pantomine and tableau, to the art of painting. Both the play and the essay represented an attack on the Commedie Française.

Diderot writes his first Salon in 1759.

Diderot begins to write his second novel in 1760.

Diderot writes his second Salon

Le Pére de famille (A Father and His Family)was published together with a long discourse on DramaticPoetry.

The play was performed by the Commedie Française in February 1761 and revived with great success in 1769, from which time it remained part of the repertoire for nearly a century. It also became popular in Germany, inspiring the young Schiller’s burgerlich comedy Kabale und Liebe. It was twice adapted for the English stage, by Sophie Lee in The Chapter of Accidents, first performed in 1780, and by John Burgoyne in The Heiress (1786).

“I am moving into the final period (of my life), without having attempted anything that could recommend me to the times to come.”

“Richardson is no more. What a loss for letters and for humanity!” If pressed to sell his library, Diderot remarks, “You would be left to me, you would be left on the same shelf with Moses, Homer, Euripides, and Sophocles”. Richardson had “carried the torch into the bottom of the carvern”, he had known “how to make the passions speak.” “All that Montaigne, Charron, La Rochefoucauld, and Nicole have put into maxims, Richardson put into practice.” (This last view seems to have been a commonplace: on 28 October 1759, Madame de Deffand told Voltaire that Richardson’s novels were “moral treatises in action”.)

A short work, published anonymously, on the origin of language.

Volume I of plates.

Written in 1761.

RAMEAU: Imagine the universe wise and philosophical; you must admit it would be unbearably dull.

Le Nevue de Rameau was not offically published during Diderot's lifetime.

Diderot's third Salon

A book-length study of the biennial exhibition at the Louvre. It was accompanied by Essays on Painting.

Volume IV of plates and remaining text.

Volumes V-XI of plates, 1767-72.

“Barbaric people have more vigour than civilized people ...Everywhere vigour and poetry decline as the philosophic spirit has made progress...(The latter) wants more strict, exact and rigorous comparisons: its cautious progress is the enemy of the fluent and the figurative...With reason there is introduced an exactness, precision, method, and, if you will excuse the word, a kind of pedantry with kills everything”.Diderot writes Salon de 1767

A short essay in which a gift of a new dressing-gown leads Diderot to wonder if he is succumbing to the corrupting hand of luxury, a doubt which he eventually dispells.

Discovered only in 1937 and given its title by Franceo Venturi, in this short work Diderot took Frederick II to task for his authoritarian views. He writes “to whom should a philosopher address himself forcefully, if not a sovereign?” He characterizes Frederick as a mediocre thinker, poor poet and bad sovereign; “May God preserve us,” Diderot concludes, “from a sovereign who resembles that kind of philosopher.”

The Pages was a rejoinder to Frederick’s reply to an anonymous treatise, Essai sur les préjugés, which appeared early in 1779 and probably came from Holbach’s circle. In addition to attacking Christianity, the Essai “denounced absolute princes as “despots”, and characterized despots as the scourges of their country, the victims of poisonous flatterers, war-loving criminals, and oppressive impostors who mislead the world with their dubious academies that are in reality nothing better that slave societies.” (Gay, The Enlightenment, Vol. II, 486.) In disgust Frederick replied to the treatise and offered a rebuttal of the premise of the work, namely, that man is made for the truth, by asserting that “Man is made for error” and that lies are essential in sound goverance.

Written in part as a rejoinder to a story by Saint-Lambert, Les Deux Amis, conte iroquois, is set in ‘distant lands’, among the North American Indians. Diderot wished to show that “greatness of soul and noble qualities are found in all situations and in all countries...and you do not have to go as far as the Iroquois to find two friends”.

This was a review Grimm asked Diderot to write of a pamphlet about Garrick and acting for the Correspondance littéraire. Over the following years he expanded and revised the piece, casting it dialogue form and entitling it Paradoxe sur le comédien. In a letter to Grimm, dated 14 November 1769, Diderot wrote, “I claim that sensibility makes mediocre actors; extreme sensibility, limited actors; cold sense and head, sublime actors.” (The editor of Diderot’s correspondence, Georges Roth, suggests that Paradoxe sur le comédien emerged from this comment.)

“Great poets, the great actors, and perhaps all the great imitators of nature in general, whoever they are, endowed as they are with a fine imagination, excellent judgment, fine tact, absolutely sure taste, have less sensibility than anyone. They are equally well equipped for too many things; they are too busy looking, recognizing, and imitating, to be vividly affected within themselves. I see them ceaselessly with their portfolios on their knees and their pencil in their hand.” (Paradoxe sur le comédien.)

Memories of his father and family, sparked off by a visit to Langres in 1770, led to this dialogue in which Diderot, his father, brother and sister discuss whether or not there are cases when it is right to disobey the law.

This work was a reply to Morellet’s attack on Galiani’s Dialogue sur le commerce des bles, published the previous year, and marked a decisive place in Diderot’s developing interest in politics. Diderot was lead to agree with Galiani’s argument that the cause of free trade in grain was mistaken after he saw the condition endured by the peasants during a visit to Langres and Bourbonne. The restrictions on the grain trade had been lifted six years earlier and in 1770 the price of corn had reach its highest level before 1787.

Andre Morellet (1729-1819) was an admirer of Diderot, a freethinking Jesuit, tutor to the grandson of the King of Poland, a prolific author and was often employed as a writer in government service. He contributed articles to the Encyclopédie and was a major contributor of the Dictionnaire of the Academie and helped secure the revival of the Academie after the revolution.

A draft version is known to have existed by September as Diderot gave a two-hour reading from it to a friend.

This short play - “the one really effective piece that he ever wrote for the stage” - seems to have been first sketched, as ‘The Play and the Prologue’, in 1770 or 1771. He revised it several times and completed it around 1783, when he was seventy. It concerns Hardouin, who embarks on a public examination of his motives and who enjoys doing things for others but in his own way, for which reason he is not always thanked.

“I, a good man, as people say? I’m nothing of the kind. I was born essentially hard, bad, perverse. I’m practically moved to tears by the tenderness of that mother for her child, her sensibility, her gratitude; I might even develop a taste for her; and despite myself I persist in the project that may make her miserable . . . Hardouin, you amuse yourself with everything; nothing is sacred to you; you’re a regular monster . . . That’s bad, very bad . . . You must absolutely get rid of this bad inclination . . . and renounce the prank I’ve planned? . . . Oh, no . . . But after this one, no more, no more. It will be the last one of my life.”

“I was born, I think, to do nothing that pleases me, to do everything that others demand, and to satisfy nobody - no, nobody - not even myself.”

“Is he good? Is he bad?”/ “One after the other.”/ “Like you, like me, like everybody.”

A dithyrambic poem denouncing injustice.

Supplement au Voyage de Bougainville wasincluded in Correspondance littéraire, September-October, 1773 and March-April, 1774.

“Examine the history of all nations and all centuries and you will always find men subject to three codes: the code of nature, the code of society, and the code of religion; and constrained to infinge upon all three codes in succession, for these codes never were in harmony. The result of this has been that there never was in any country...a real man, a real citzen, or a real believer”.

A short essay published in an edition of Correspondance littéraire, 1812. “They have preserved all the energy of their natural egoism and self-interest...more civilized than us on the outside, they have remained true savages within, all of them more or less machiavellian. The symbol of women in general is that of the Apocalypse, on whose forehead was written: MYSTERY.”

A favourite work of Diderot’s which he kept on revising. It consists of a dialogue about the art of acting in which the first of two speakers argues that what characterises a great actor is not some superior power of feeling but an exceptional and total lack of feeling: “it is extreme sensibility which makes a mediocre actor; mediocre sensibility which makes the multitude of bad actors; and a total lack of sensibility which produces sublime actors”. The Paradox has been debated by a whole succession of great actors, among them Talma, Coquelin, Henry Irving and Jouvet, but the work extends beyond acting to ‘genius’ in general.

Hemsterhuis was a Dutch philosopher, known as the “Dutch Plato”, and met Diderot in Holland and asked him to comment on his Lettre sur l’homme et ses rapports. First published in 1773, the Lettre is a short treatise setting out Christian principles in idealistic, quasi-Platonic terms, with the aim to “combat by Reason the fashionable philosophy of the day: scepticism, materialism and atheism”. Diderot’s commentary was only discovered in the early 1960’s.

Refutation of Helvétius, written between 1773-4, first appeared in Grimm’s manuscript journal La Correspondance littéraire, January 1783-1786. The Correspondance littéraire was a cultural newsletter which regularly informed a small number of princes and monarchs in Germany, Sweden and Russia about intellectual life in Paris. It never had more than fifteen subscribers. Diderot began to contribute articles in 1757.

Helvetuis’s posthumous On Man, which had just appeared in Holland because no publisher dare touch it in France, was an example of what Hemsterhuis’s called “the fashionable philosophy of the day.” Diderot, reading it for the first time, was shocked by the inadequacy of Helvétius’s “self-interest” theory of Man and he began a critique of the book.

“It is really true that physical pain and pleasure, which are perhaps the sole principle of animal behaviour, are also the sole principle of human conduct. No doubt we need to be organised as we are, and to have the faculty of sensation, to be capable of action; but it seems to me that these are essential and primordial conditions, a mere sine qua non, and that the direct and immediate motives of our aversions and desires are something quite other.”

“It is very hard to think cogently about metaphysics or ethics without being an anatomist, a naturalist, a physiologist, and a physician.”

Diderot did, however, think the book was full of good ideas and that its errors could be easily remedied. “The difference between you and Rousseau is that Rousseau principles are false, and the consequences true, while your principles are true and the consequences false. In exaggerating his principles, Rousseau’s disciples will be nothing but madmen; yours, moderating your consequences, will be wise men.” This work of moderation results in a series of objections to Helvétius bold pronouncements, designed not to refute but “restrain” him: “He says: Education does everything. Say: Education does a great deal. He says: Constitution does nothing. Say: Constitution does less than you think.” Again: “He says: Character depends entirely on circumstances. Say: I think that they modify it. He says: One gives a man the temperament one wants to give him . . . Say: Temperament is not always an invincible obstacle to the progress of the human spirit.”

Diderot’s corrections disappear as soon Helvétius moves from implicit to explicit politics; quoting Helvétius’s praise of Frederick - “There is nothing better than the arbitrary government of princes who are just, humane, and virtuous “ - Diderot cannot disguise his disappointment: “And you Helvétius, quote this tyrant’s maxim in high praise! His virtues are the most dangerous and the most certain of his seductions; They insensibly habituate the public to love, respect, serve his successor, evil and stupid as he may be . . . One of the greatest misfortunes that can happen to a nation would be two or three reigns of a power that is just, mild, enlightened, but arbitrary: the people will be led by happiness to the complete forgetfulness of their privileges, and into perfect slavery.”

Published in La Correspondance littéraire in April.

Reflections and memoranda on the situation in France and Russia, based on conversations Diderot held with the Empress during the autumn of 1773.

A commentary on Catherine’s proposed constitutional reforms.

Aimed against Frederick II, these were a series of reflections “written by the hand of a sovereign in the margin of Tacitus”.

In 1765 Catherine had drawn up a Preparatory Instruction, the Nakaz, to be considered by the Estates General in 1767. It set out advanced ideas, drawn largely from Montesquieu and Beccaria. However, the assembly was dissolved before the document was considered, as war broke out between Russia and Turkey, but the document remained the offical version of Catherine’s political intentions. The document was translated into French in 1769 and it provided Diderot with the occasion for his most developed piece of political writing. The Observations were only sent to Catherine after Diderot’s death. They were not well received.

At Catherine’s request, Diderot wrote this full-length work on educational reforms; “to instruct a nation is to civilize it; to broaden its knowledge is to lead it away from the primitive state of barbarism”.

Three works concerned with sexuality, apparently a result of a short-lived affair with Madame de Maux.

A longer version of this work entitled Essai sur les regnes de Claude et de Neron was published in 1782. It was Diderot’s first work to be published in France with his own name on the title page since 1758. When it was published in December it received an extremely hostile press and Diderot was threatened with arrest. He made an apology in person and there the matter ended. The essay on the life and work of Seneca was written at Holbach’s request, to accompany a translation of Seneca’s works begun by La Grange, the tutor of Holbach’s children, and completed by Naigeon.

“After reading Seneca, am I the same man I was before I read him? That’s not so - it can’t be so.”

Unpublished note, first printed by Herbert Dieckmann in his Inventaire du fonds Vandeul (1951), 257.

Published in installments from 1778 in Correspondance littéraire.

Diderot’s passionate defence of Raynal’s Histoire against Grimm’s criticisms; “the book I like, and which kings and their courtiers detest, is the book which causes Brutuses to be born”.

“O Seneca! you are and will always be, with Socrates, with all the illustrious unhappy men, with all the great men of antiquity, one of the sweetest links between my friends and me, between the educated men of all ages and their friends. You have remained the subject of our frequent conversations; and you will remain the subject of theirs.”

“The magistrate deals out justice; the philosopher teaches the magistrate what is just and unjust. The soldier defends his country; the philosopher teaches the soldier what a fatherland is. The priest recommends to his people the love and respect of the gods; the philosopher teaches the priest what the gods are. The sovereign commands all; the philosopher teaches the sovereign the origins and limits of his authority. Every man has duties to his family and his society; the philosopher teaches everyone what these duties are. Man is exposed to misfortune and pain; the philosopher teaches man how to suffer.”

“I love wisdom in evidence, like the athlete in the arena: the strong man recognizes himself only on the occasions that he has to show his power.”

In 1782 Diderot worked on the final revisions to Est-il bon? Est-il mechant?, Jacques le fataliste, La Religieuse and Le Neveu de Rameau, completing them by the following year.

Posthumous publication

Posthumous publication.

Published in Leipzig, translated by Goethe under the title Rameaus Neffe. It appeared in France in 1821, when it was translated back from Goethe’s German. Goethe found Diderot’s novel “more audacious and contenue, more full of brilliance and impudence, more immorally moral” than anything he could have expected to read.