DIDÉROU, DENYS, an eminent French writer, was the son of a cutler, and born at Langres in the year 1713. 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 had received 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 thus neglected his business, his allowance was withheld, which obliged him to make provision for himself. 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. He even indulged in poetry and works of invention; but attached himself chiefly to more serious studies. He possessed a ready flow and great animation of language in conversation; and these qualities, with a decisive tone and manner, procured for him 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, among whom he had now enlisted himself, and became one of its most zealous disciples. The same work was afterwards reprinted under the title of Étrennes aux Esprits Forts. It was greatly read, and it supposed contributed much to the diffusion of those free opinions which had now become so prevalent in France. Soon after this period, in conjunction with his friend D'Alembert, the plan of the vast undertaking, the Dictionnaire Encyclopédique, was laid. The professed object of this work was to become a magazine for every branch of human knowledge; but at the same time, it has been alleged that it was also intended by the authors and editors as the great engine by means of which the established opinions, whether of a religious or political nature, which they supposed had their origin in fraud and superstition, should be subverted. The province of this work which was entrusted to Diderot was the description of Arts and Trades, (Arts et Metiers). But, besides, he contributed many other articles in various departments of science. His writings in the Dictionary have been considered as extremely verbosé and diffuse; and in all of them he is too fond of metaphysical subtleties and the pompous parade of scientific language. The first edition of the Dictionary was completed between the years 1751 and 1767; and although Diderot was occupied in this laborious undertaking for a period of nearly 20 years, the recompense which he obtained is said to have been extremely small.

During this time he composed various other works. Among these he published, "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 which it contained, had given offence to the government, for which the author was kept in confinement for six months at Vincennes. This piece was soon followed by another, entitled "A letter on the Deaf and Dumb, for the use of those who hear and speak," 2 vols. 12mo, 1751. "The Sixth Sense," published in 1752; "Thoughts on the interpretation of Nature," 1754; "The Code of Nature," 1755, are similar works, and may be ranked in the same class. His moral character was considerably affected by the publication of Bijoux Indiscrets, 2 vols. 12mo; which is a collection of licentious tales; for this indeed he made some kind of compensation, when he published two prose comedies, Le Fils Naturel, 1757; and Le Pere 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. It has indeed received universal admiration. He published afterwards a pamphlet "On Public Education," which contains undoubtedly some useful hints; but at the same time it proposes many things which are 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 work, and was published in 1779. Among some observations on this work by the Monthly Reviewers, the author of it is thus characterized: "The works of M. Diderot, says the writer, have long since disgusted the modest votaries of true philosophy, by the tone of arrogance and self-sufficiency, and the froth and fumes of a declamatory eloquence, that form their essential and distinctive character." "It contains, it is farther added, like the other writings of that author, a glaring mixture of good and bad; of brilliant thoughts and obscure reasonings; of sentences that dart from the imagination with the energy of lightning, and cloudy periods of metaphysical rhetoric, that convey either no ideas, or false ones."

The character of Diderot suffered considerably from some defamatory attacks which he 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 Genevan philosopher, it would appear that they expected some anecdotes which would not have been much to their honour. In one of his letters Rousseau thus speaks of Diderot. His words are remarkable, as they are equally applicable to his own character. "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 some irritability of temper, he was a kind husband and a tender parent. At the conclusion of the Dictionary, the state of his affairs rendered: dered 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 and promoter 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 50,000 livres; and he was to have the use of it during his life. Some of his biographers, with what truth we pretend not to say, have not hesitated to charge him with disposing of it a second time; and when some person commissioned by the empress wished to see it, the philosopher declined the visit by excuses till he 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. He died suddenly, as he rose from table, on July 31st, 1784. His literary and philosophical works have been collected and published in 6 vols 8vo.