HE was born on October 5, 1713, at Langres in Champagne, thirty-eight miles from Dijon. His father, Didier Diderot, was a cutler specializing in surgical instruments; the family had been engaged in cutlery for two hundred years past. Denis did not inherit his forebears’ contented stability of occupation and belief, but he never ceased to reverence his father’s simple honesty and quiet charity. “My son, my son,” so Denis quoted him, “an excellent pillow is that of reason, but I find that my head rests still more softly on that of religion and the laws”;1 here in one sentence were the two voices of eighteenth-century France. Another son became a priest, and a sworn enemy to Denis. A sister entered a convent.
Denis himself verged on priesthood. From his eighth to his fifteenth year he attended a Jesuit school in Langres; at twelve he was tonsured, wore a black cassock, practiced asceticism, and resolved to become a Jesuit. Later he explained this as an exuberance of his fluids: he had mistaken “the first stimuli of a developing sexuality for the voice of God.”2 Didier rejoiced at his son’s new vocation, and gladly escorted him to Paris (1729) to enroll him in the Jesuit Collège Louis-le-Grand. There, in 1732, the youth received the master’s degree. But, as in many cases, the Jesuits lost a novice by sharpening a mind. Denis discovered that Paris had even more brothels than churches. He dropped his cassock and piety and became a lawyer’s apprentice. Soon he discarded the law and entered upon a decade of transient occupations and garret poverty. After long patience his father cut off his allowance, but his mother sent him secret subsidies. Denis borrowed money, and sometimes repaid. He tutored boys in mathematics, wrote sermons for priests, and served as a bookseller’s hack. Meanwhile he continued his studies of mathematics, Latin, Greek, and English, and picked up considerable Italian. He was lawless, but he was avid of knowledge and life. He never learned discipline, but he learned nearly everything else.
Purse empty, glands full, he fell in love and decided to marry. Antoinette Champion was his senior by three years and eight months, but she was a woman. She reproached him with his libertine youth; he assured her that this was a prelude to marital fidelity; he would be her faithful mate forever. “It is to you that my last love letters are addressed, and may heaven punish me as the most wicked of all men, the most traitorous of all men, if ever in my life I write one to anyone else.”3 His finest letters violated this vow. Antoinette’s mother, yielding to her daughter’s tears and the suitor’s fluent tongue, agreed to the marriage on condition that he secure his father’s consent. Diderot gathered sufficient funds to pay the coach fare to Langres, 180 miles away.
Arrived, he impressed his father by receiving there the proofs of his translation from the English of a history of Greece. Didier offered to support him in any career Denis should choose; but some choice must be made. The youth announced his eagerness to marry; the father upbraided him as a shiftless ingrate; the son answered insolently, and vowed to marry with or without paternal consent or coin. Didier had him imprisoned in a local monastery. Denis escaped, walked ninety miles to Troyes, caught a coach there, and returned to Paris.
But Mme. Champion was resolute; her daughter should not marry a man severed from parents and patrimony. Diderot, living almost penniless in a dingy room, fell seriously sick. Antoinette heard of this, rushed to him, and dragged her mother with her; the mother’s resistance broke down. Together they nursed the ailing philosopher; and on November 6, 1743, “Nanette” and her “Ninot” (as they called each other) were united at midnight in a little church that thrived on clandestine marriages. Nine months later they rejoiced in the birth of a daughter, who, six weeks later, died. Three other children came, of whom only one survived childhood. Antoinette proved to be a faithful wife but an inadequate companion, quite unable to follow her husband’s intellectual flights, and volubly discontent with the petty income he made as a translator. He returned to his baccalaureate cafés, living on coffee, playing chess. By 1746 he had taken a mistress, Mme. de Puisieux. For her he wrote his Pensées philosophiques, and Les Bijoux indiscrets,and the Lettre sur les aveugles.
He had long since succumbed to the fascination of philosophy—which draws us ever onward because it never answers the questions that we never cease to ask. Like most freethinkers of that century, he was shaken to his intellectual roots by reading Montaigne and Bayle, finding on nearly every page of the Essais and the Dictionnaire some arresting thought. Perhaps through Montaigne’s rich references to the pagan classics, he was drawn to further study of the Greek and Roman philosophers—especially to Democritus, Epicurus, and Lucretius; he himself was the “laughing philosopher” of his age, a materialist bubbling with spirit. He could not afford to visit England, like Voltaire and Montesquieu, but he learned to read English readily, even to enjoy its poets and dramatists; we shall see him responding to the sentiment of Thomson, and defending, like Lillo, the drama of middle-class life. He was stirred by Francis Bacon’s call to the conquest of nature by organized scientific research, and proceeded to exalt experiment as the supreme tool of reason. He attended—now in these formative years and again in preparing the Encyclopédie— lectures on biology, physiology, and medicine; for three years he followed the conférences of Rouelle on chemistry, taking 1,258 folio pages of notes. He studied anatomy and physics, and kept abreast of the mathematics of his time. He went on from Bacon to Hobbes and Locke and the English deists. He translated (1745) Shaftesbury’s Inquiry concerning Virtue and Merit, adding “reflections” of his own. He continued through all vacillations to believe with Shaftesbury that the good, the true, and the beautiful are near allied, and that a moral code based on reason rather than religion can adequately serve social order.
Bursting with all this stimulation, and with his own expansive imagination, he issued anonymously in 1746 his Pensées philosophiques. It was sufficiently radical to be attributed to La Mettrie, and eloquent enough to be ascribed to Voltaire; perhaps it owed something to both. It began with a defense of the “passions.” Here the intrepid reasoner, agreeing with his friend Rousseau, argued that no harm would be done if philosophy should “say a word in favor of reason’s rivals, since it is only the passions [les grandes passions] that can raise the soul to great things. Without the passions there would be nothing sublime, either in morals or in works; the arts would return to their infancy, and virtue would be limited to petty deeds.”4 But passions without order would be destructive; some harmony must be established among them; a way must be found by which one may check the other. Hence we need reason, and must make this our supreme guide. Here was an early attempt of the Enlightenment to reconcile reason with feeling, Voltaire with Rousseau.
Like Voltaire, Diderot was in this first period of his development a deist. The evidences of design compel belief in an intelligent deity. Mechanism can explain matter and motion but not life or thought. The future atheist challenged the atheist to explain the marvels of insect life recently displayed in the researches of Réaumur and Bonnet.
Have you ever noticed in the reasoning or actions of any man more intelligence, order, sagacity, consistency, than in the mechanism of an insect? Is not the Divinity as clearly imprinted in the eye of a gnat as the faculty of thought is in the works of the great Newton? … Just think that I objected to you only the wing of the butterfly and the eye of a gnat, when I could have crushed you with the weight of the universe!5
Nevertheless Diderot rejected with scorn the God revealed in the Bible; that deity seemed to him a monster of cruelty, and the Church that spread this conception was denounced by him as a fountainhead of ignorance, intolerance, and persecution. Could anything be more absurd than a God who makes God die on the Cross in order to appease the anger of God against a woman and a man four thousand years dead? And “if,” as some theologians reckoned, “there are a thousand damned for every soul saved, then the Devil wins the argument, and without abandoning his son to death.” Diderot recognized no other divine revelation than nature itself, and he pleaded with his readers to rise to a conception of deity worthy of the universe that science had revealed. “Élargissez Dieu!” he demanded. “Enlarge and liberate God!”6
The Parlement of Paris ordered the book to be burned by the public executioner on the charge of “presenting to restless and bold minds the most absurd and most criminal thoughts of which the depravity of human nature is capable, and of placing all religions, by an affected uncertainty, nearly on the same level in order to end up by not recognizing any.”7 Advertised by the burning (July 7, 1746), the little volume found an unexpected number of readers. It was translated into German and Italian; and when it was whispered about that Diderot was the author, he rose at once to a place near Voltaire. He received fifty Louis from the publisher; these he turned over to his mistress, who needed new clothes.
As Mme. de Puisieux’ wants expanded, Diderot wrote another book (1747). The parish priest heard of it, and begged the police to protect Christianity from this second assault. They surprised the author in his home and confiscated the manuscript; or, some say, they contented themselves with his promise not to publish it. In any case the Promenade du sceptique remained unprinted till 1830. It could not add to his fame, but it relieved his feelings. Using the philosopher’s favorite dodge, the dialogue, he allowed a deist, a pantheist, and an atheist to expound their views of divinity. The deist repeats with vigor the argument from design; Diderot was not yet convinced that the remarkable adaptation of means to ends in organisms could be explained by a blind process of fortuitous evolution. The atheist insists that matter and motion, physics and chemistry, are a better explanation of the universe than a deity who merely postpones the problem of origin. The pantheist, who has the last word, holds that mind and matter are co-eternal, that together they constitute the universe, and that this cosmic unity is God. Perhaps Diderot had been reading Spinoza.
The year 1748 was exciting and laborious. Antoinette had borne a son, and Mme. de Puisieux was demanding the emoluments of adultery. Probably to raise money quickly, Diderot now wrote a licentious novel, Les Bijoux indiscrets. According to his daughter, the future Mme. de Vandeul (whose Mémoires pour servir â l’histoire de la vie et des ouvrages de Diderot cannot be trusted without corroboration), he had remarked to his mistress that writing a novel was a comparatively simple matter. She challenged the statement; he wagered that he could turn out a successful novel in a fortnight. Obviously imitating the younger Crébillon’s Le Sopha (1740), where a sofa recounted the amours under which it had groaned, Diderot imagined a sultan’s magic ring which, when pointed to the “indiscreet jewels” of a woman’s person, caused them to confess their experiences. As the ring was turned upon thirty ladies, the interest of the two volumes seldom flagged. The author mingled with the ribaldry some provocative remarks on music, literature, and the theater, and added a dream in which the sultan sees a child called “Experiment” grow larger and stronger until it destroys an old temple called “Hypothesis.” Despite these intrusions of philosophy, the book realized its aim: it made money. The publisher Laurent Durand paid Diderot twelve hundred livres for the manuscript, and though the volumes could be sold only “under the counter,” they proved remunerative. Six French editions were printed in 1748; ten editions appeared in France between 1920 and 1960.“Les Bijoux … is Diderot’s most published work.”8
He varied his mood by composing scientific treatises. He valued highly his Mémoires sur différents sujets de mathématique (1748), which contained learned and original discourses on acoustics, tension, air resistance, and “a project for a new organ” that anyone could play. Some of the essays won high praise from The Gentleman’s Magazine and the Journal des savants, even from the Jesuit Journal de Trévoux, which invited more of such researches “on the part of a man as clever and able as M. Diderot seems to be, of whom we should also observe that his style is as elegant, trenchant, and unaffected as it is lively and ingenious.”9 Diderot continued throughout his life to make such desultory sallies into physical science, but he leaned increasingly to problems of psychology and philosophy. And in almost every field he was the most original thinker of his time.