DIDEROT, DENIS, a French writer and philosopher, was the son of a cutler, and born at Langres in the year 1712. He received his education among the Jesuits, and being destined for the church by one of his uncles, who had a canonry to bestow upon him, he assumed the tonsure. But he discovered so little inclination for the ecclesiastical profession, that his father sent him to Paris to prosecute his studies, and afterwards placed him with an attorney. It soon appeared, however, that he was more attached to different departments of literature and science than disposed to submit to the drudgeries of the profession to which his father had destined him; and having neglected his business, his allowance was withheld, which obliged him to shift for himself, and to give lessons in order to procure a subsistence. The studies to which Diderot devoted his attention were extremely various. Physics, geometry, metaphysics, moral philosophy, and belles-lettres, were at different times the objects of his pursuit; and he even indulged in poetry and works of invention. But he attached himself chiefly to graver and more serious studies. Diderot possessed great fluency and animation of language in conversation; and this accomplishment, with a decisive tone and manner, procured him both partizans and protectors.
One of the first of his publications was a translation of Stanyan's History of Greece. In the year 1745 he published Principles of Moral Philosophy, 12mo, a work by which he obtained some reputation. But the year following, when he published a piece entitled Pensées Philosophiques, he acquired considerable celebrity. This work was highly commended by the partizans of the new philosophy, amongst whom he had now enlisted himself. The same work was afterwards reprinted under the title of Étrennes aux Esprits Forts: it was very much read; and is supposed to have contributed greatly to the diffusion of those free opinions which had now become so prevalent in France. Soon after this period, Diderot, in conjunction with D'Alembert, concerted the plan of that vast undertaking, the Dictionnaire Encyclopédique. The professed object of this work was to form a magazine of every branch of human knowledge; but it has been alleged that it was also intended by the authors and editors as the great engine by means of which established opinions, whether of a religious or political nature, which they supposed had their origin in fraud and superstition, were to be subverted. The department of this work which was entrusted to Diderot was the description of arts and trades (arts et métiers). In fact, he was the principal architect of this great edifice; and, besides the Prospectus, and the Système des Connaissances Humaines, which has been much commended on account of its classification, he contributed many articles in various departments of science. But his writings in the Dictionary have been considered as extremely verbose and diffuse; and in all of them he is too fond of metaphysical subtleties and the pompous parade of scientific language. The first two volumes of the Dictionary appeared in the year 1751, and the first edition was completed and published in 1767; but although Diderot was occupied in this laborious undertaking for a period of nearly twenty years, the recompense which he obtained for his labours is said to have been extremely small.
During this time he composed various other works. Amongst these may be mentioned A Letter on the Blind, for the use of those who see. This work made a good deal of noise, and, in consequence of some of the sentiments it contained, gave offence to the government, for which reason the author was detained in confinement during six months at Vincennes. This piece was soon followed by another, entitled A Letter on the Deaf and Dumb, 2 vols. 12mo, 1751. The Sixth Sense, which was published in
Diderot. 1752; Thoughts on the interpretation of Nature, which appeared in 1754; and The Code of Nature, in 1755; are similar works, and may be ranked in the same class. His moral character was considerably affected by the publication of Bijoux Indiscrets, in two vols. 12mo, which is a collection of licentious tales; but for this he made some kind of compensation when he published two prose comedies, entitled Le Fils Naturel, 1757, and Le Père de Famille, 1758, which are not only interesting as dramatic pieces, but exhibit a pure and correct morality. The latter is considered as one of the best comedies of the sentimental kind which has appeared on the French stage, and it has accordingly been much admired. He afterwards published a pamphlet on Public Education, which undoubtedly contains some useful hints, but at the same time it proposes many things which are utterly absurd and impracticable. To the list of his works now mentioned we may add an eulogy on Richardson, which is full of warmth and enthusiasm; and an Essay on the Life and Writings of Seneca the Philosopher. This was his last production, and was published in 1779.
The character of Diderot suffered considerably from some defamatory attacks which he had made on his former friend Rousseau, who had quarrelled with the French philosophers, and had separated himself from their school. From the Confessions of the philosopher of Geneva, it would appear that they expected of him some anecdotes which would not have redounded much to their honour. In one of his letters Rousseau, speaking of Diderot, says, "Although born with a good heart and an open disposition, he had an unfortunate propensity to misinterpret the words and actions of his friends, and the most ingenuous explanations only supplied his subtle imagination with new interpretations against them."
Diderot was married and had a family; and, although he possessed considerable irritability of temper, he was, it seems, a kind husband and a tender parent. At the conclusion of the Dictionary, the state of his affairs having rendered it necessary for him to dispose of his library, it was purchased by the empress of Russia, who, with the king of Prussia, was at that time the great encourager of literature and literary men. These sovereigns were also considered as disciples of the French school. The price which Diderot received for his library was fifty thousand livres, and he was to have the use of it during his life. But some of his biographers, with what truth we know not, have not hesitated to charge him with disposing of it a second time; they state, that when some person commissioned by the empress wished to see it, the philosopher declined the visit on various pretexts, until he had had time to fill it with books borrowed from booksellers. The examination, it is obvious, must have been extremely superficial, otherwise the truth would have been at once detected. Diderot had been admitted a member of the Academy of Sciences at Berlin; but the doors of the French Academy remained closed against him to the last. He died suddenly, as he rose from table, on the 31st July 1784. His literary and philosophical works were collected and published by his friend Nageon, in 15 vols. 8vo, at Paris, in 1798. This collection has been enlarged, in subsequent republications, to 22 vols. 8vo, Paris, 1821; and it contains a Memoir of Diderot.
Diderot, it would seem, had a hand in several of the most remarkable works of his time, published under the names of others. "Who does not know," says Grimm, in his Correspondance, "that nearly a third of the Histoire Philosophique of Raynal belongs to him? He laboured on it during two years, and a considerable part of it was even composed under my own eyes. Diderot himself was often startled at the boldness with which he had made his friend
the abbé speak. 'Who,' asked he, 'who will venture to subscribe this?' 'I,' replied the abbé, 'I will subscribe it; proceed, I tell you.' What man of letters is there who may not easily recognise in the book De l'Esprit (of Helvetius), and in the Système de la Nature, all the fine passages which are, and could only be, from the pen of Diderot? If we undertook to make a more complete enumeration, we should run the risk of naming many ungrateful individuals." (Correspondance Littéraire, Philosophique, et Critique, tom. iv. p. 85.) Grimm further states that Diderot furnished a great number of pages to the Système de la Nature, and that he likewise laboured, though to less extent, on the Système Social and the Morale Universelle, also published by Baron d'Holbach. Such were some of the indirect literary efforts of Diderot. But neither as a writer nor as a philosopher did he make for himself any very enviable reputation. As a writer he was decidedly a bad model; he had neither plan nor connection, and knew not how proprie communia dicere, whilst his style was deformed by obscurity, neologisms, and a tone of insufferable dogmatism; but nevertheless he was often vigorous, sometimes eloquent, and hit off happy traits of expression, as well as striking truths, which, however, would have gained much by being more simply enunciated. In fact, he had frequently the air of being in cathedra; he aimed at ambitious formularies, and fatigued by his strained style, by his prodigal sallies, and by an enthusiasm which seldom appeared natural. As a philosopher he wrote under the influence of a heated imagination rather than under that of cool reason. He was almost always exalted and extravagant; seldom or never simple and natural. His friends, however, have celebrated his goodness, his frankness, his easy and obliging character, and the vigour and entrainement of his conversation. Grimm, who has praised him warmly in his Correspondance, regards Diderot as having had the most naturally encyclopaedical head of any man that ever lived. He admires his energy, his warmth, the variety of his ideas, the multiplicity of his acquirements, the impetuous tumult of his imagination, and the charm and irregularity of his conversation. Then he adds, "However willingly I may pardon all men for believing nothing, I think that it would have been very desirable for the reputation of Diderot, perhaps even for the honour of his age, if he had not been an atheist. The determined war which he thought himself obliged to carry on against God, caused him to lose the most precious moments of his life." (Correspondance, 3me partie, tom. iv. p. 87.) But Nageon, who is less considerate than Grimm, praises his friend without qualification, adding, besides, that "his age has not done him justice." It is possible indeed that some persons may have too much depreciated the merit of Diderot; but others again exalted it beyond all measure. The general opinion in regard to him, however, seems now to be pretty well fixed, and posterity has at length put him in his right place. He had talent; he was capable of warmth and elevation; but he wanted sagacity, moderation, and taste. "He has written fine pages," says Marmonel in his Mémoires, "but he never knew how to make a book." He adopted a desolating and destructive system, and he dishonoured his cause by the exaggeration of most of his principles, and by the license which reigns in many of his productions. This explains the reason why he never entered the academy, whose doors, as we have already stated, were constantly shut against him, notwithstanding the anxious desire of his friends to procure him admission. Voltaire, who had himself solicited his election, appears latterly to have become less enamoured of the merit of Diderot, and even to have formally censured some of his works. D'Alembert also cooled towards him, and at last they did not even see each other. His rupture with
Rousseau, however, was the work of the latter, who began the war which was afterwards waged between them. But Diderot maintained his connection with Baron d'Holbach, whose sentiments approached the nearest to his own on several important points; and in the society of the baron he was relished and admired by reason of his facility in speaking on subjects of all sorts, and no doubt also by his antipathy to that creed, and to those institutions, which were no longer revered or respected. On this topic he never tired, and his friends often amused themselves with affording him opportunities to abandon himself to his imagination, or, in other words, to blaspheme for their diversion. In an unexcited state he exhibited constraint, awkwardness, timidity, and even a kind of affectation. He was never truly Diderot except when his fancy had transported him as it were beyond himself. Enthusiasm had become the condition of being most natural to his mind, nay, even to his voice and features; and he was himself only when in a state of intellectual inebriety. Grimm has reproached him with having consumed in fugitive conversations the time which he might have devoted to more durable labours; but Diderot loved to talk, especially when he could indulge his vehement volubility without interruption; for, as Voltaire once remarked on leaving a company where Diderot had engrossed the whole talk, "Cet homme-là n'est pas propre pour le dialogue." The correspondence recently published has thrown but little new light on the character of this remarkable man, nor has it tended in any material degree to increase the estimation in which his talents and dispositions were previously held by the world.