(b. Langres, France, 5 October 1713; d. Paris, France, 31 July 1784)
Diderot’s importance in the history of science derives from his having edited the Encyclopédie—with the partial collaboration of d’Alembert—and from a sensibility that anticipated and epitomized moral, psychological, and social opportunities and stresses attending the assimilation of science into culture.
Early Life and Work. He came from energetic stock. His father, Didier, was a prosperous master-cutler who aspired to higher spheres for his children. His mother, born Angélique Vigneron, was of a family of tanners with a tendency to the priesthood. Diderot was the eldest child of seven. One sister, Angélique, became a nun and died mad. A brother, Didier Pierre, took orders and became archdeacon of Langres. It may have been fortunate for the Church that nothing beyond the tonsure at the age of thirteen came of the would-be nepotism of a maternal uncle who thought to make a priest of Diderot in order to leave his nephew his own benefice.
Like many of his fellow philosophes, Diderot was well-educated by the Jesuits. Having completed their collège at Langres, he was sent to Paris in the winter of 1728–1729. There he enrolled in the Collège d’Harcourt and also followed courses in two other famous establishments, the Collège Louis-le-Grand and the Collège de Beauvais. In 1732 he took his degree maîre-ès-lettres of the University of Paris. Thereafter his father supposed him to be entering upon legal studies. In fact Diderot was enjoying his freedom, intellectual and amorous, in the literary Bohemia of the capital. Abandoning the pretense of law, he drifted into a catchpenny life, ghost-writing sermons for hard-pressed preachers and missionaries, applying himself to mathematics and teaching it a bit, and perfecting his English and undertaking translations—of which the occasional faithlessness expresses wit, not ignorance. For to the ordinary appetites of Grub Street he added that for information, and unlike the hacks around him, he did study. There have been few writers—perhaps only Voltaire—whose lightness of touch has more gracefully dissembled a capacity for work.
The most considerable of these early commissions planted in his mind the idea that burgeoned in the Encyclopédie. In 1744 Diderot, together with three other writers, put in hand for the publisher Briasson the translation of A Medicinal Dictionary: Including Physic, Surgery, Anatomy, Chemistry, and Botany..., a multivolume work that except for Diderot’s connection with it would weigh quite forgotten in both languages upon library shelves.1 Qualifying himself (for he was not the man to remain ignorant of what he was translating), he attended public courses in anatomy and physiology given by one Verdier, and later those of a certain formidable Mlle. Biher. He thus began an adult self-education in science that he long continued and that put him in the way of the medical humanism which forms a still insufficiently appreciated strain in the naturalistic thought of the Enlightenment and which issued in the philosophy of vitalistic materialism. His marriage in 1743 to Anne-Toinette Champion turned out unhappily almost from the start, although their surviving child, later Mme. de Vandeul, was a comfort to him in old age.
In the 1740’s Diderot and his fellow writers began to form a recognizable circle of like-minded free spirits on whom he later drew for contributions to the Encyclopédie. He met Rousseau in 1742, Condillac in 1744, and came to know d’Alembert, Grimm, Mably, d’Holbach, and others, and to be known to Voltaire, to whose deistic point of view on science he increasingly opposed the naturalistic standpoint he was developing for himself. The publications by which he made himself known for an original writer went far in the direction of overt skepticism. “I write of God,” he announced in the opening sentence of Pensées philosophiques (1746), embarking upon a celebration of the passions and identifying them with the creative energies of nature, which, it soon appears, is indistinguishable from God. For although the standpoint from which Diderot was attacking absurdities and inequities in the scriptural tradition was ostensibly that of the deism of Shaftesbury, from whom he borrowed many a theological observation, his inspiration in natural philosophy was actually the pantheism of Spinoza, and never Newton.
The Lettre sur les aveugles of 1749, his first truly original work, goes further and undermines deism. In it he initiated a device that he employed more regularly in later writings. A prominent contemporary figure is adopted to be spokesman for views that Diderot was just then trying out. Through the person of Nicholas Saunderson, a blind mathematician who was Lucasian professor in Cambridge, Diderot exhibited how unconvincing it is in the eyes of the sightless to base the existence of God upon the evidence for design in nature. The essay combines humanity with skepticism. In handling this favorite psychological puzzle of eighteenth-century sensationalism—how the world appears to a man deprived of one of his senses, or to whom sight or hearing is suddenly restored—Diderot found himself questioning the artificiality with which the associationists, and notably his friend Condillac, abstracted the operation of the five senses one from another in some mechanical and imaginary sensorium.
He ended by disputing as gratuitous the conclusion of the self-styled empiricists that on regaining sight a blind man, once he learned to use his eyes at all, would not recognize the difference between a sphere and a cube without touching them. There was a psychological shrewdness in Diderot that rejected the notion that touch and sight can be independent even for analytic purposes. His sense of what people are really like, related to a highly personal distrust of all abstractions, animates all his writings.
The most widely read of these pre-Encyclopedic writings was almost certainly Les bijoux indiscrets (1747). It is a salacious fantasy and, in certain passages in the vein of Fanny Hill, a pornographic one, written gaily rather than grossly, and no doubt mainly for gain. Overtones convey the innocence of sensual enjoyment, and the tale is not out of character. It no longer seems so incongruous coming from a champion of humanity as it did prior to the recent recurrence of a cultural symbiosis, at once libertine and libertarian, between open sensuality—aesthetic, gustatory, sexual—disdain for convention, and the belief that freedom is to be asserted against the corruptions and hypocrisies of society and culture and not merely secured within the operations of law and government. The latter would have satisfied Voltaire, but did not interest Diderot. Nor would he with Rousseau reject society and culture. His yearning was for their transfiguration into a congruence with nature.
Such radicalism made itself felt. Inevitably the authorities thought him dangerous and placed him in detention for more than three months in the summer of 1749 in the confines of the château of Vincennes. There he acknowledged authorship of the three works just mentioned—intemperate thoughts that happened to slip out, he called them—and there he continued preparation of what in an executive sense was the great work of his life, the editing of the Encyclopédie, ou Dictionnaire raisonné des sciences, des arts, et des métiers, so fully the signet of the French Enlightenment that the word “Encyclopedists” has become almost a synonym for its exponents. Even his imprisonment was one of those enlightened oppressions that did not prevent a subversive character from reading, writing, or receiving friends.
The Encyclopédie. Specifying the importance of the Encyclopédie in the history of science does not require following in detail the vexed story of its preparation and publication:2 its commercial origin at the instance of the publisher Le Breton, who intended a straightforward translation from the English of Chambers’ Cyclopaedia and John Harris’ Lexicon Technicum; his enlistment of Diderot and d’Alembert in 1747 after a false start with the Abbé de Gua de Malves as editor, d’Alembert to oversee the mathematical subjects; the beating of bushes for contributors and nagging of contributors for copy; the appearance of the first volume in 1751 to applause from the enlightened and muttering from court and clergy; d’Alembert’s desertion in 1758 on the eve of the suspension following volume VII and the subsequent prohibition of the enterprise by the authorities; publication, nevertheless, of the remaining ten volumes with the provisional protection of the chief official charged with censorship, the liberal-minded Malesherbes; the triumphant completion of the text of the work in 1766 consisting finally of seventeen volumes of articles and eleven of splendid plates, largely technical in subject matter. This was not merely the work of reference originally imagined by the publisher, who had had to take three other firms into partnership in order to finance the scale to which Diderot in his energy and enthusiasm had expanded it. It was not merely a place to look things up. A proper dictionary, in Diderot’s view, should have “the character of changing the general way of thinking.”3
The ideological impact of the Encyclopédie in its social, economic, political, juridical, and theological aspects is naturally more famous than its technical side. Having largely assimilated the ideology of progress, toleration, and government by consent, the general historical consciousness continues to be titillated by the alarm aroused at the time in traditionalist and privileged quarters over articles like “Certitude,” by the Abbé de Prades, an emancipated clergyman who preferred the reasonings of Locke to the obscurities of Revelation; “Fornication,” which introduces the word as a term in theology; “Salt,” which enlarges on the injustice to the poor of excise taxes on items of subsistence; and “Political Authority,” which denied the existence in nature of the right of any man to exercise sovereignty over others.
Diderot’s purpose, however, was deeper than unsettling the authorities by purveying tongue-in-cheek reflections on superstition and injustice in the guise of information. The technical contents of the Encycbpédie were central to that purpose, which was the dignification of common pursuits over and against the artificiality and pretense of the parasitic encrustations in society and reciprocally the rationalization and perfection of those pursuits in the light of modern knowledge. It would be a mistake to seek the scientific importance of the Encyclopédic only or even mainly in articles contributed or commissioned by d’Alembert on topics of mathematics, mechanics, or formal science. True, those articles are often (although not always) valuable summaries of the state and resources of a subject, and were so regarded at the time. But technically the central thrust of the Encyclopédie was in its descriptions of the arts and trades, and for that the initiative and responsibility were Diderot’s, harking back certainly to his provincial background among the thriving artisans of Langres. The account of the cutlery industry is one of the best and clearest in the work, and in the article “Art” is a passage that may be taken as his credo:
Let us at last give the artisans their due. The liberal arts have adequately sung their own praises; they must now use their remaining voice to celebrate the mechanical arts. It is for the liberal arts to lift the mechanical arts from the contempt in which prejudice has for so long held them, and it is for the patronage of kings to draw them from the poverty in which they still languish. Artisans have believed themselves contemptible because people have looked down on them; let us teach them to have a better opinion of themselves; that is the only way to obtain more nearly perfect results from them. We need a man to rise up in the academies and go down to the workshops and gather material about the arts to be set out in a book which will persuade artisans to read, philosophers to think on useful lines, and the great to make at least some worthwhile use of their authority and their wealth.
Diderot wrote this himself as he did many of the articles describing particular trades and processes. Not in every case was he able to “go down to the workshops” and base his account on actual observation, and a number are composed from printed sources or other secondary information. It was not on the articles alone, however, but on the illustrative plates to which most of them were keyed that Diderot and his publishers relied to fulfill the promise made to subscribers of a systematic description of eighteenth-century industry in its essential processes and principles. Censorship had interrupted publication of articles in 1759, but there could be no objection to going ahead with technical plates containing no sensitive matter. The series began in 1762 and filled the gap until the remaining ten volumes of text could appear all at once four years later. (The supplementary volume of plates and four of text published by Panckoucke were not edited by Diderot.)
Delicate questions arise about the publication of these plates, not concerning Diderot’s treatment of the censorship, but rather his originality and treatment of the rights of others. They were preceded in their appearance by angry charges of having been lifted from engravings prepared for the Academy of Sciences. Since its founding in 1666, during the administration of Colbert, that body had been vested with the responsibility of maintaining a scientific surveillance over French industry. Not a line had appeared of its constitutionally prescribed project for a description of arts and trades, although its most recent director, the naturalist and metallurgist Réaumur, had commissioned a large number of plates before his death in 1757. The Academy rushed one volume of these into print in 1761 in order to forestall Diderot, who himself or through agents must indeed have found, bought, or bribed access to Réaumur’s plates during the early stages of preparing the Encyclopédie All that can be said in extenuation is that copyright did not exist in the eighteenth century, that title to artistic and literary property was an amorphous matter, and that whoever engraved the various plates it was through Diderot”s deeds and misdeeds that they appeared as a collection, a systematic record of industrial life and methods.
At their best the plates of the Encyclopédie are executed with the sweep and style of chefs d”oeuvre of technical illustration, notably in the series devoted to the glass industry, in the coverage afforded to Gobelin tapestries, and in depicting the blast furnace and forge. Typically the reader is given something like an anatomy of machines, a physiology of processes. The technique of illustration might be thought to derive from the anatomy of Vesalius two centuries before. Several of his plates are among those that reappear without acknowledgment as do several of Agricola”s depicting sixteenth-century mining. Normally the first plate in each series gives an overall picture of an installation and is followed by sectional views, one lengthwise and one crosswise. Thereafter, cutaway representations penetrate to the intermediate assemblies, sometimes shown in place and sometimes in isolation. Finally, there are drawings of the individual parts, pieces, and tools.
The plates exhibit the state of manufacturing processes just before the industrial revolution, then in its earliest, largely unperceived stages in England. Science is often taken to be the fruitful element in technology, the progenitor of industrialization, and so it appears in the Encyclopédie, but only if we limit what we understand by the influence of science to its descriptive role. Basic theory had very little to offer the manufacturer in any industry in the eighteenth century, and it was descriptive science addressed to industry that transformed it by rationalizing procedures and publicizing methods. In effect the Encyclopédie turned craftsmanship from lore to science and began replacing the age-old instinct that techniques must be guarded in secret with the concept of uniform industrial method to be adopted by all producers.
Not that the changeover was welcomed by practitioners or easily achieved. Many tradesmen, full of suspicion, resisted inquiries or deliberately misinformed Diderot and his associates after accepting their gratuities. Terminology alone created obstacles. Each trade had its own, often barbarous, jargon. A great many artisans had no desire to understand from a scientific point of view what it was they were doing and preferred working by traditional routine. “It is only an artisan knowing how to reason who can properly expound his work,”4 exclaimed Diderot in a moment of irritation, a remark that might seem to render somewhat circular his fundamental conception of science and reason as the educators of industry, but that brings out the necessity for its rationalization if the truly popular purpose of the Encyclopédie was to be achieved in the deepest sense—that is, in the easing of labor, its liberation from routine, and the summons to pride in its enlightenment.
Moral and Philosophic Position. Particular articles in the Encyclopédie exhibit the development of Diderot’s scientific sensibility into the psychic materialism of his later years, through his reading of chemistry, natural history, comparative anatomy, and physiology, complemented by the experience and observation of humanity, but it is more satisfactory to follow the writings that he found time and inspiration to leave as his literary legacy. The term legacy is deliberate for it was one of the peculiarities of Diderot’s intellectual personality that, prolific writer that he was, it seems to have been more important to him to express his mind than to publish and persuade. Of the major books conveying his philosophy of nature, only De l’interprétation de la nature was printed during his lifetime, the first edition in 1753 and a revision in 1754, just when he was winding up his researches on the arts and trades. For the rest (to name the important), Le rêve de d’Alembert, Entretienentre Diderot et d’Alembert, and Suite de l’entretien were written in 1769 and published in 1830; the Supplément au voyage de Bougainville was begun in 1772 and published in 1796; and the Éléments de physiologie, begun in 1774 and taken up again in 1778, was published in 1875. (It was the same with his best literary works: the picaresque novel Jacques le fataliste was printed in the completed form in 1796, and the theatrical piece Est-il bon, Est-il méchant? in 1834.
Most extraordinary of all, his masterpiece, Le neveu de Rameau—a complex dialogue that, in shifting the locus of immorality back and forth between the ostensibly degenerate individual and the actually corrupt society, anticipates the diabolism although not the sexual inversion in the writings of Jean Genet—was first printed in a German translation by Goethe from an inexact manuscript and published in French in a largely faithful version only in 1884. Vicissitudes too complicated to follow here led these manuscripts through various minor German courts and the major court of Catherine the Great in St. Petersburg, which Diderot was persuaded to enliven briefly by his presence in later years.
It is possible to identify sources of much of Diderot’s scientific inspiration:5 the chemistry in the lectures of Rouelle at the Jardin du Roi, the natural history in Buffon, the physiology in Haller, the psychology in La Mettrie, and the medical doctrine in his frequent association with Bordeu. But this record of nonpublication, and the consequent implausibility of supposing that his views could have formed a system exerting a coherent influence upon either contemporary or later writers, make it more reasonable to regard his response to the scientific world picture as an anticipation of the program recognizable later, and rather recurrently than consequentially, as that of biological romanticism—an attempt to construct an account of the operations of nature in categories of organism and consciousness rather than impersonal matter in inanimate motion.
Occasionally it has been supposed in Diderot scholarship that he reached this position in a lifelong progression from some solid Newtonian basis in his youth; and it is true that he published in 1748 (the year of Les bijoux indiscrets!) a curious little collection, Mémoires sur différens sujets de mathématiques; and further true that in one memoir, the fifth, he mentions that he had studied Newton formerly, “if not with much success, at least with zeal enough,” but that to raise questions about Newton today “is to speak to me of a dream of years gone by.”6 Although very interesting in several respects, the memoirs themselves give no reason beyond the title for thinking that Diderot had in fact ever been seized of Newtonian mathematical physics.
The first and most considerable is a summary of musical acoustics dressed out in elementary mathematical formalism. Its object is to establish that musical pleasure consists in perception of the relations of sounds as they are propagated in nature and is no mere matter of caprice or culture, although such factors certainly affect the judgment. Ever the good encyclopedist, Diderot reported faithfully the work on vibrating strings and pipes of Taylor, d’Alembert, Mersenne, Sauveur, and Euler. Although in no way original physically, the discussion is, nevertheless, a highly individual approach to the physics of beauty in a manner not to be attempted successfully before the work of Helmholtz. The other essays are much slighter. The second and third are geometrical and concern the design of certain devices that Diderot was proposing to mathematical and musical instrument makers. The fourth is a (virtually computerized) program for enlarging the repertory of barrel organs, and rather wickedly suggests that resistance to the improvement of these popular instruments was a function not of musical taste but of the self-interest and restrictiveness of musicians and music teachers. The last reassures those who have failed to master Newton by taking him to task for an allegedly false assumption about air resistance in the pendulum experiments that he reported in the scholium following the sixth corollary to the laws of motion in the Principia.
Five years later three volumes of the Encyclopédie were in print, and the opening paragraphs of De l’interprétation de la nature predict that mathematics is about to go into a decline, and deservedly so. On all grounds it had exaggerated its claim to be the language of science. Metaphysically it falsifies nature by depriving bodies of the qualities of odor, texture, appearance, or taste through which they appeal to our senses. It impoverishes mechanics by requiring it to operate with the superficial measurements of bodies instead of seeking, as the chemist is said to do, for the activity that animates them. Worst of all, it dries up and blights the sensibilities of those who cultivate it and whom it renders inhuman in their judgments. Such will be the effect of any science that ceases to “instruct and please,” for the only thing that will make a science appealing and keep it vital is its capacity to improve the character, understanding, and moral fiber of its possessors. Mathematics leads mainly to arrogance, however, pretending to equip a finite intelligence to plumb the infinite where it has no business. Man being insatiable, we need some criterion not found in mathematics by which to establish bounds between what we need to know and the infinite unknown. So let it be our interests, let it be utility, “which, in a few centuries, will establish boundaries for experimental science, as it is about to do for mathematics.”7
Apparently a formless rumination, De l’interprétation de la nature is actually written in an artful stream of consciousness, a reverie on the Experimental Art, the true road to a science of nature. That road lies through craftsmanship, and here we rejoin the editor of the Encyclopédie. For Diderot, it is the common touch that opens up the truth, and genius that is to be distrusted, inclining in its pride to draw a mathematical veil of abstraction and obscurity between nature and the people. It is wrong to say that there are some truths too deep or hard for ordinary understandings. Certainly common men will never attach any value to what cannot be proven useful, and they are right. Only a philosophy derived from actually handling objects is innocent in that it involves no a priori ideas. A kind of intuition in the true craftsman has the quality of inspiration for it derives from genuine participation. Such a man will recognize it in himself, in his solidarity with natural objects. In his hands science and nature are one in the actual operation with materials. Not some mathematical abstraction from nature but manual intimacy with nature, living oneness with nature, is the arm of science.
For nature is the combination of its elements and not just an aggregate. It is continuity that science is to seek in nature, not divisibility. The interesting property of molecules is their transience, not their existence. In genetics the notion of emboîtement is unacceptable because of its atomistic implications. For there are no fixed limits in nature. Male and female exist in each other (a fascination with hermaphroditism and the merging of the sexes is another motif in his writings that seems curiously up-to-date in the 1970’s). Mineral, vegetable, and animal kingdoms blend, species into species, and only the stream of seminal fluid is permanent, flowing down through time. “Tout change; tout passe; il n’y a que le tout qui reste” (“Everything changes; everything passes; nothing remains but the whole”);8 and in Lerêve de d’Alembert, Diderot invokes two models to exhibit this unity. The first is the swarm of bees, for the solidarity of the universe is social. It has the oneness of the social insects, among whom laws of community are laws of nature. In the second the universe is a cosmic polyp, time its life unfolding, space its habitation, gradience its structure, and certainly the two ideas that mattered most to Diderot were those of social naturalism and universal sensibility.
In Diderot’s philosophic dialogue with a fictitious d’Alembert, that distinguished mathematical colleague admits that the notion of a sensitive matter containing in itself principles of movement and consciousness is more immediately comprehensible than that of a being which is inextended and yet occupies extension, which differs from matter and yet is united to it, which follows its course and moves it without being moved. “Is it by accident,” this straw d’Alembert is made to ask
that you would recognize an active sensibility and an inert sensibility, in the way that there is a live force and a dead force?—a live force that manifests itself in motion of translation, a dead force that manifests itself by pressure; an active sensibility that is characterized by certain remarkable actions in animals and perhaps in plants, and an inert sensibility the existence of which is assured by the passage to the state of active sensibility?
“Marvelous,” Diderot as interlocutor replies, “you said it.”9.
And in the rêve that continues the discussion, d’Alembert, apparently ailing, has been put into a trance—it may be a delirium—in which he speaks truths that would not have come to him from the normal detachment of the mathematical analyst quantifying his inert blocks of matter. Now his interlocutors are his mistress, Mlle. de l’Espinasse, and a doctor, Diderot’s mentor in medical vitalism, Théophile de Bordeu, who recognizes these verities for what they are and draws them out in a kind of psychic analysis of the realities of a world alive. He it is who sees nature in the perspective of human nature, and who, therefore, knew the answers all the time. “There is no difference,” Diderot makes Mlle. de l’Espinasse observe, “between a doctor keeping watch and a philosopher dreaming.”10
1. Scholarship on Diderot occasionally falls into confusion about the identity of this work, published in 3 vols. (London, 1743–1745), attributing it sometimes to the authorship and sometimes to the firm of Ephraim Chambers, publisher of a famous Cyclopaedia. In fact the author was Robert James and the publisher T. Osborne. The French translation was published by Briasson in 6 vols. (1746–1748) and entitled Dictionnaire universel de médecine, de chirurgie, de chymie, de botanique, d’anatomie, de pharmacie, et d’l’histoire naturelle....
2. See Jacques Proust, Diderot et l’Encyclopédie (Paris, 1963).
4. Diderot article, “Encyclopédie.” in the Encyclopédie. vol. V.
5. Jean Mayer, Diderot, homme de science (Rennes, 1959).
6.Op. cit., pp. 202–203.
7.Op. cit., par. 6.
8. “Le rêve de d’Alembert,” in Paul Verniére, ed., Oeuvres philosophiques de Diderot (Paris, 1956). pp. 299–300.
9. “Entretien entre d’Alembert et Diderot,” ibid., p. 260.
10.Ibid., p. 293.
I. Original Works. There is no modern edition of the works of Diderot, although one is said to be in preparation. The most recent is Oeuvres complètes, J. Assezat and M. Tourneux, eds., 20 vols. (Paris, 1875–1877). A useful selection is Oeuvres philosophiques de Diderot, Paul Verniére, ed. (Paris, 1956).
There are a number of selections from the Encyclopédie in L’Encyclopédie(Extraits) (Paris, 1934); The Encyclopédie of Diderot and d’Alembert, Selected Articles, John Lough, ed. (Cambridge, 1954); Textes choisis de l’Encyclopédie, ed., with commentary, by Albert Soboul (Paris, 1962); and Encyclopedia Selections, Nelly S. Hoyt and Thomas Cassirer, eds. (New York, 1965).
The undersigned has edited a selection from the technical plates: A Diderot Pictorial Encyclopedia of Trades and Industry... With Introduction and Notes, 2 vols. (NewYork, 1959).
II. Secondary Literature. The literature on Diderot is immense. Besides works mentioned in the notes, readers will gain entry into it from Abraham Lerel, Diderots Naturphilosophie (Vienna, 1950); Jean-Louis Leutrat, Diderot (Paris, 1967); J. Lough, Essays on the Encyclopédie of Diderot and d’Alembert (London, 1968); René Pomeau, Diderot, sa vie, son oeuvre, avec un exposé de sa philosophie (Paris, 1967); and Franco Venturi, La jeunesse de Diderot (1713–1753) (Paris, 1939).
The exposition of De l’interprétation de la nature in this article follows closely the discussion of the significance of Diderot’s scientific views for the intellectual history of the Enlightenment in the undersigned’s Edge of Objectivity (Princeton, 1960), ch. 5.
Charles Coulston Gillispie
The French philosopher (seeker of wisdom), playwright, and novelist Denis Diderot is best known as the editor of the Encyclopédie, a summary of information on all subjects that also questioned the authority of the Catholic Church.
On October 15, 1713, Denis Diderot was born in Langres, Compagne, France, one of Didier and Angelique Diderot's seven children. His father was a cutler (a maker of cutting tools). As a child Denis was considered a brilliant student by his teachers, and it was decided that he should serve the church. In 1726 he enrolled in the Jesuit (Catholic order of priests devoted to educational work) college of Louis-le-Grand and probably later attended the Jansenist Collège d'Harcourt. In 1732 he earned a master's in philosophy (the study of the universe and man's place in it).
Diderot then abandoned religion as a career and decided to study law. The death of his sister, a nun, from being overworked in the convent may have affected Diderot's opinion of religion. In 1734 Diderot decided to seek his fortune by writing. Against his family's consent, he spent the next ten years earning his living by translating English books and tutoring the children of wealthy families. He spent his leisure time studying and chasing after women. In 1743 he further angered his father by marrying Anne Toinette Champion.
In January 1746 André François le Breton and his partners were granted permission to publish a ten-volume encyclopedia. On the advice of the mathematician Jean D'Alembert and with the consent of Chancellor D'Aguesseau, Diderot was named general editor of the project.
For more than twenty-six years Diderot devoted the bulk of his energies to the writing, editing, and publishing of the Encyclopédie. For Diderot the aim of the work was "to assemble the knowledge scattered over the face of the earth; to explain its general plan to the men with whom we live … so that we may not die without having deserved well of the human race." Such was the plan and the purpose of the Encyclopédie, and it was also the motto of the Enlightenment (the eighteenth-century awakening of political and social thought that laid the foundation for the French and American revolutions). But the project was more than just the gathering of all available knowledge; it was also a learning experience for all those connected with it. It introduced Diderot to crafts, fine arts, and many other areas of learning. It was an outlet for his curiosity, his scholarly interests, and his creativity.
In 1751 D'Alembert's Preliminary Discourse and the first volume of the Encyclopédie were published. In January 1752 the second volume appeared, but the opposition of Jesuits and other critics forced a temporary suspension. Publication was soon resumed and continued at the rate of one volume a year until 1759, when the Royal Council banned further operations. Diderot and Le Breton, however, continued to write and publish the Encyclopédie secretly until 1765, when official approval was regained. In 1772 the completed work was published in seventeen volumes of text and eleven volumes of illustrations.
Diderot continued to devote himself to other writings throughout the period of his association with the Encyclopédie. In 1746 he published Philosophical Thoughts, which discussed the relationship between nature and religion. He stated his belief that virtue (moral excellence) could be achieved without religious beliefs. In Sceptics Walk (1747) and Letters on the Blind (1749) Diderot slowly turned to atheism (a disbelief in the existence of God). Religion became a central theme in his writings, and he angered public officials, who considered him a dangerous leader of radicals (those holding extremely different views).
In 1749 Diderot was imprisoned for three months because of his opinions in Philosophical Thoughts. He had stated, "If you impose silence on me about religion and government, I shall have nothing to talk about." After his release he toned down his published works. Therefore, most of his antireligious works and several of his novels were not published during his lifetime.
Following the completion of the Encyclopédie in 1772, Diderot went into semiretirement; he wrote steadily but did not publish all of his works. His earnings as editor of the Encyclopédie guaranteed him a decent income, which he added to by writing literary criticism. In addition, he sold his library to Empress Catherine of Russia (1729–1796), who allowed him to keep it while he lived and paid him an annual salary as its librarian. On July 30, 1784, Diderot died in the home of his daughter.
For More Information
Crocker, Lester G. Diderot: The Embattled Philosopher. New York: Free Press, 1966.
Furbank, P. N. Diderot: A Critical Biography. New York: A. A. Knopf, 1992.
Havens, George R. The Age of Ideas. New York: Holt, 1955.
Simon, Julia. Mass Enlightenment. Albany: State University of New York Press, 1995.
The French philosopher, playwright, and novelist Denis Diderot (1713-1784) is best known as the editor of the Encyclopédie.
On Oct. 15, 1713, Denis Diderot was born in Langres, Compagne, into a family of cutlers, whose bourgeois traditions went back to the late Middle Ages. As a child, Denis was considered a brilliant student by his Jesuit teachers, and it was decided that he should enter the clergy. In 1726 he enrolled in the Jesuit college of Louis-le-Grand and probably later attended the Jansenist Collège d'Harcourt. In 1732 he earned a master of arts degree in philosophy. He then abandoned the clergy as a career and decided to study law. His legal training, however, was short-lived. In 1734 Diderot decided to seek his fortune by writing. He broke with his family and for the next 10 years lived a rather bohemian existence. He earned his living by translating English works and tutoring the children of wealthy families and spent his leisure time studying. In 1743 he further alienated his father by marrying Anne Toinette Champion.
On Jan. 21, 1746, André François le Breton and his partners were granted permission to publish a 10-volume encyclopedia. On the advice of the distinguished mathematician Jean D'Alembert and with the consent of Chancellor D'Aguesseau, Diderot was named general editor of the project.
For more than 26 years Diderot devoted the bulk of his energies and his genius to the writing, editing, and publishing of the Encyclopédie. For Diderot, the aim of the work was "to assemble the knowledge scattered over the face of the earth; to explain its general plan to the men with whom we live … so that we may not die without having deserved well of the human race." Such was the plan and the purpose of the Encyclopédie, and it was also the credo of the Enlightenment. But the project was more than just the compilation of all available knowledge; it was also a learning experience for all those regularly connected with it. It introduced Diderot to technology, the crafts, the fine arts, and many other areas of learning. It was an outlet for his curiosity, his scholarly interests, and his creativity.
In 1751 D'Alembert's Preliminary Discourse and the first volume were published. In January 1752 the second volume appeared, but the opposition of the Jesuits and other orthodox critics forced a temporary suspension. Publication was soon resumed and continued at the rate of one volume a year until 1759, when the Royal Council forbade further operations. Diderot and Le Breton, however, continued to write and publish the Encyclopédie secretly until 1765, when official sanction was resumed. In 1772 the completed work was published in 17 volumes of text and 11 volumes of plates under the title Encyclopédie, ou Dictionnaire raisonné des sciences, des arts, et des métiers.
Throughout the period of his association with the Encyclopédie, Diderot continued to devote himself to other writing. In 1746 he published Philosophical Thoughts, which was concerned with the question of the relationship between nature and religion. He viewed life as self-sufficient and held that virtue could be sustained without religious beliefs. In Sceptics Walk (1747) and Letters on the Blind (1749) Diderot slowly turned from theism to atheism. Religion became a central theme in his writings, and he aroused the hostility of public officials who considered him a leader of the radicals, "a clever fellow, but extremely dangerous."
In 1749 Diderot was imprisoned for 3 months because of his opinions in Philosophical Thoughts. Although he had stated, "If you impose silence on me about religion and government, I shall have nothing to talk about," after his release he reduced the controversial character of his published works. Therefore most of his materialistic and anti-religious works and several of his novels were not published during his lifetime.
During his long literary career Diderot moved away from the mechanical approach to nature, which was characteristic of the Englishtenment's use of the discoveries of Sir Isaac Newton. Such works as D'Alembert's Dream, Conversation between D'Alembert and Diderot, Thoughts on the Interpretation of Nature, Elements of Physiology, and Essay on Seneca vividly point to the evolution of his thought and to its modernity.
In his mature writings Diderot tends to see man as an integral part of an organic and vitalistic nature, governed by laws that are incomprehensible to him. Nature, according to Diderot, is a continually unfolding process, which reveals itself, rather than being revealed by man. Forms in nature develop from earlier forms in a continually evolving process, in which all elements, animate and inanimate, are related to one another. Man can know nature only through experience; thus rationalistic speculation is useless to him in understanding nature.
Diderot is one of the pre-19th-century leaders in the movement away from mathematics and physics, as a source of certain knowledge, to biological probability and historical insight. As one modern scholar has stated, Diderot's approach to nature and philosophy was that of mystical naturalism.
Following the completion of the Encyclopédie, Diderot went into semiretirement; he wrote but infrequently published his works. His earnings as editor of the Encyclopédie guaranteed him a modest income, which he supplemented by writing literary criticism. In addition, he sold his library to Empress Catherine of Russia, who allowed him to keep it while he lived and paid him an annual salary as its librarian. On July 30, 1784, Diderot died in the home of his daughter, only 5 months after the death of his beloved mistress and intellectual companion, Sophie Voland.
The great paradox of Diderot's life is found in the tensions that existed between his basically bourgeois nature and his bohemian tendencies. This struggle was mirrored in his novel Rameau's Nephew, in which the staid Rameau and his bohemian nephew represent aspects of Diderot's personality. Fittingly, Diderot's last words, "The first step toward philosophy is incredulity," are an adequate measure of the man.
Two biographies of Diderot are outstanding: Lester G. Crocker, Diderot: The Embattled Philosopher (1952), an accurate and penetrating work, but with a tinge of romanticism; and Arthur M. Wilson, Diderot: The Testing Years, 1713-1759 (1957), apparently a more scholarly work, but in reality lacking only the romanticism of Crocker. Both works show notable scholarship in the area of Diderot studies. Among the shorter works, George R. Havens, The Age of Ideas (1955), contains four excellent and highly original chapters on Diderot. □
Diderot, Denis, illustrious French man of letters and philosopher; b. Langres, Oct. 5, 1713; d. Paris, July 30, 1784. In his work Memoirs sur differents sujets de mathematiques (The Hague, 1748) are the essays “Des principes d’acoustique” and “Projet d’un nouvel orgue,” the latter being an impracticable idea for a new kind of barrel organ. For his writings on music, see B. Durand- Sendrail, ed., D. D.: Ecrits sur la musique (Paris, 1987).
—Nicolas Slonimsky/Laura Kuhn/Dennis McIntire