by Will Durant
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.
II. THE BLIND, THE DEAF, AND THE DUMB: 1749–51
He was especially attracted by a question which the Irishman William Molyneux had raised about 1692: Will a man born blind who has learned to distinguish a cube from a sphere by touch, be able, if his sight is restored, to differentiate at once a cube from a sphere, or will he require, before he can make this distinction, some experience of the relations between forms touched and the same forms seen? The latter answer had been given by Molyneux and his friend Locke. In 1728 Willian Cheselden operated successfully upon a fourteen-year-old boy who had been blind from birth; the boy had to be trained before he could differentiate forms by sight alone. Diderot noted also the career of Nicholas Saunderson, who had lost his sight at the age of one and had never recovered it, but, by making for himself a kind of mathematical Braille, had acquired such proficiency as to be appointed professor of mathematics at Cambridge.
Early in 1749 Réaumur invited a select group to see what would happen when the bandages were removed from the eyes of a woman who had undergone an operation to cure her congenital blindness. Diderot was piqued that neither he nor any other of the philosophes had been included in the invitation, and with his usual recklessness he suggested that Réaumur had arranged to have the unveiling take place before “certain eyes of no consequence.”10 According to Diderot’s daughter this phrase offended Mme. Dupré de Saint-Maur, who prided herself on her eyes, and who was the current mistress of the current directeur de la librairie, or chief censor of publications, the Comte d’Argenson (Marc Pierre, younger brother of René Louis, the Marquis).
On June 9 Durand published Diderot’s Lettre sur les aveugles à l’usage de ceux qui voient (Letter on the Blind for the Use of Those Who See). It took the form of a letter addressed to Mme. de Puisieux. It began with an account of the visit that Diderot and some friends had made to a blind winegrower. They were struck by the sense of order shown by the blind man—a sense so sure that his wife relied on him at night to put back in its proper place everything disturbed during the day. All his surviving senses were keener than those of normal men. “The smoothness of the flesh has [for him] no less subtle nuances than the sound of the voice, and there is no fear that he will mistake another woman for his wife, unless he gains by the exchange.”11 He could not understand how one could know a face without touching it. His sense of beauty was confined to tactile values, pleasantness of voice, and utility. He had no shame in nudity, since he thought of clothing as a protection against weather, not as a concealment of the body from others’ eyes. Theft he considered a major crime, because he was so helpless against it.
Diderot concluded that our ideas of right and wrong are derived not from God but from our sensory experience. Even the idea of God has to be learned, and it too, like morality, is relative and diverse. The existence of God is doubtful, for the argument from design has lost much of its force. Yes, there are evidences of design in many organisms and organs, as in the fly and the eye; but there is no sign of design in the universe as a whole, for some parts are hindrances—if not fatal enemies—to other parts; almost every organism is bound to be eaten by another. The eye seems a wonderful instance of adjustment of means to ends, but there are gross imperfections in it (as Helmholtz would later point out in detail). There is a creative spontaneity in nature, but it is half blind, and runs to much disorder and waste. Pretending to quote from a “Life and Character of Dr. Nicholas Saunderson” by William Inchlif (who apparently never existed), Diderot made the blind professor say, “Why talk to me of all that fine spectacle which has never been made for me? … If you want me to believe in God you must make me touch him.”12 In the imaginary biography Saunderson rejected God,I and attributed the order of the universe to a natural selection of organs and organisms by the survival of the fittest.
All defective combinations of matter have disappeared, and only those remained in which the mechanism implied no important contradiction, and which could subsist by their own means and reproduce themselves.… Even now the order of the world is not so perfect but that monstrous products appear from time to time.… What is this world? A composite subject to revolutions all of which indicate a persistent tendency to destruction, a rapid succession of beings that follow each other, push each other, and disappear.13
Diderot concluded with agnosticism: “Alas, madame, when we put human knowledge in the balance of Montaigne, we shall not be far from accepting his motto. For what do we know? Of the nature of matter, nothing. Of the nature of mind or thought, still less, nothing whatever.”14
All in all, this Lettre sur les aveugles is one of the outstanding productions of the French Enlightenment. It is fascinating as a narrative, brilliantly perceptive as psychology, imaginatively suggestive as philosophy, tiresome only toward the end of its sixty pages. It contains some indelicacies, hardly in place in an epistle supposedly addressed to a lady; but perhaps Mme. de Puisieux was accustomed to Diderot’s mixture of plebeian frankness with erudite discourse. For good measure the essay included a detailed proposal for what later took the name of Louis Braille.15
Voltaire, who was then (1749) in Paris, wrote to Diderot an enthusiastic commendation of the Lettre:
I have read with extreme pleasure your book, which says much and suggests more. For a long time I have esteemed you as much as I despise the stupid barbarians who condemn what they do not understand. …
But I confess that I am not at all of the opinion of Saunderson, who denies a God because he was born blind. Perhaps I am mistaken, but in his place I should have recognized a very intelligent Being, who had given me so many supplements to sight. …
I desire passionately to converse with you, no matter whether you think you are one of his works or whether you think you are a nicely organized portion of an eternal and necessary matter. Before my departure from Lunéville I should like you to give me the honor of taking a philosophical dinner with me, at my house, together with several sages.
Diderot replied (June 11):
The moment when I received your letter, monsieur et cher maître, was one of the happiest of my life.
Saunderson’s opinion is no more mine than yours.… I believe in God, but I get along very well with atheists.… It is very important not to mistake hemlock for parsley, but not at all important whether or not you believe in God. The world, said Montaigne, is a ball that he has abandoned to the philosophers to bat around …16
Before anything could come of this correspondence Diderot was arrested. The go
vernment, angered by public criticism of the humiliating Peace of Aix-la-Chapelle, put several of its critics in jail, and thought it time to check Diderot. Whether the atheism lurking in the Lettre had brought protests from the clergy, or whether Mme. Dupré de Saint-Maur, resenting Diderot’s remark about “inconsequential eyes,” had prodded her lover to action, we do not know. In any case the Comte d’Argenson sent a lettre de cachet (July 23, 1749) to the Marquis du Châtelet, governor of the Fortress of Vincennes: “Receive in the Château de Vincennes the man Diderot, and hold him there until a further order from me.”17 Early the next morning the police knocked at Diderot’s door. They searched his rooms and found two or three unbound copies of the Lettre sur les aveugles, plus boxes of material that Diderot was preparing for the epochal Encyclopédie. They carried him off to Vincennes (on the outskirts of Paris), where he was lodged solitary in a cell of the gloomy castle. He was allowed to keep with him a book which he had had in his pocket when arrested—Paradise Lost. He now had leisure to read it carefully. He annotated it in no orthodox spirit, and used its vacant pages for writing down some thoughts on less godly topics. He made ink by scraping slate from the walls, grinding it, and mixing it with wine. A toothpick served him for a pen.
Meanwhile his wife, left desolate with her three-year-old son, hurried to Police Lieutenant General Berryer, and implored him to release her husband. She disclaimed any knowledge of his writings. “All I know is that his writings must resemble his conduct. He esteems honor a thousand times dearer than life, and his works reflect the virtues he practices.”18 If Antoinette knew nothing about Mme. de Puisieux, the police did. More effective was a plea from the men who had already engaged Diderot to edit an encyclopedia; they assured the Comte d’Argenson that the enterprise could not proceed without his prisoner. On July 31 Berryer sent for Diderot and questioned him. He denied authorship of the Lettre, of the Pensées, of the Bijoux indiscrets. Berryer knew that he was lying, and sent him back to Vincennes.