Narrow circumstances had their share in the versatility of Diderot’s genius as well as in the variety of his labors. Son of a cutler at Langres, a strict and virtuous man, Denys Diderot, born in 1715, had at first been intended by his father for the church. He was educated at Harcourt College, and he entered an attorney’s office. The young man worked incessantly, but not a law-book did he open. “What do you mean to be, pray?” the lawyer asked him one day; “do you think of being an attorney?” “No.” “A barrister?” “No.” “A doctor?” “No more than the rest.” “What then?” “Nothing at all. I like study, I am very happy, very contented, I ask no more.” Diderot’s father stopped the allowance he had been making his son, trusting thus to force him to choose a profession. But the young man gave lessons for a livelihood.
“I know a pretty good number of things,” he wrote towards the end of his life, “but there is scarcely a man who doesn’t know his own thing better than I do. This mediocrity in every sort is the consequence of insatiable curiosity and of means so small, that they never permitted me to devote myself to one single branch of human knowledge. I have been forced all my life to follow pursuits for which I was not adapted, and to leave on one side those for which I had a call from inclination.” Before he was thirty years old, and without any resource but his lessons and the work of every sort he did for third parties, Diderot married; he had not asked the consent of his parents, but this did not prevent him from saddling them before long with his wife and child. “She started yesterday,” he writes quite simply to his father, “she will be with you in three days; you can say anything you like to her, and when you are tired of her, you can send her back.” Diderot intended to be free at any price, and he threw off, one after another, the fetters he had forged for himself, not without remorse, however, and not without acknowledging that he was thus wanting to all natural duties. “What can you expect,” he would exclaim, “of a man who has neglected wife and daughter, got into debt, given up being husband and father?”
Diderot never neglected his friends; amidst his pecuniary embarrassments, when he was reduced to coin his brain for a livelihood, his labor and his marvellous facility were always at the service of all. It was to satisfy the requirements of a dangerous fair friend that he wrote his Pensees philosophiques, the sad tale of the Bijoux indiscrets and the Lettre sur les Aveugles, those early attacks upon religious faith which sent him to pass a few months in prison at the Castle of Vincennes. It was to oblige Grimm that he for the first time gave his mind to painting, and wrote his Salons, intended to amuse and instruct the foreign princes. “A pleasure which is only for myself affects me but slightly and lasts but a short time,” he used to say; “it is for self and friends that I read, reflect, write, meditate, hear, look, feel. In their absence, my devotion towards them refers everything to them. I am always thinking of their happiness. Does a beautiful line strike me, they shall know it. Have I stumbled upon a beautiful trait, I make up my mind to communicate it to them. Have I before my eyes some enchanting scene; unconsciously, I meditate an account of it for them. To them I have dedicated the use of all my senses and of all my faculties, and that perhaps is the reason why everything is exaggerated, everything is embellished a little in my imagination and in my talk; and they sometimes reproach me with this, the ingrates!”
It was, further, in conjunction with his friends and in community of ideas that Diderot undertook the immense labor of the Encyclopaedia. Having, in the first instance, received a commission from a publisher to translate the English collection of [Ephraim] Chambers, Diderot was impressed with a desire to unite in one and the same collection all the efforts and all the talents of his epoch, so as to render joint homage to the rapid progress of science. Won over by his enthusiasm, D’Alembert consented to share the task; and he wrote the beautiful exposition in the introduction. Voltaire sent his articles from Delices. The Jesuits had proposed to take upon themselves a certain number of questions, but their co-operation was declined: it was a monument to philosophy that the Encyclopaedists aspired to raise; the clergy were in commotion at seeing the hostile army, till then uncertain and unbanded, rally organized and disciplined around this vast enterprise. An early veto, soon, however, taken off, compelled the philosophers to a certain moderation; Voltaire ceased writing for the Encyclopaedia; it was not sufficiently free-going for him. “You admit articles worthy of the Trevoux journal,” he said to D’Alembert. New severities on the part of the Parliament and the grand council dealt a blow to the philosophers before long: the editors’ privilege was revoked. Orders were given to seize Diderot’s papers. Lamoignon de Malesherbes, who was at that time director of the press, and favorable to freedom without ever having abused it in thought or action, sent him secret warning. Diderot ran home in consternation. “What’s to be done?” he cried; “how move all my manuscripts in twenty-four hours? I haven’t time even to make a selection. And, above all, where find people who would and can take charge of them safely?” “Send them all to me,” replied M. de Malesherbes; “nobody will come thither to look for them.”
Feeble governments are ill served even by their worthiest servants; the severities ordered against the Encyclopaedia did not stop its publication; D’Alembert, however, weary of the struggle, had ceased to take part in the editorship. Naturally cool and moderate, when it was nothing to do with Mdlle. de Lespinasse, the great affection of his life, the illustrious geometer was content with a little. “Twelve hundred livres a year are enough for me,” he wrote to the Great Frederick who was pressing him to settle in his dominions. “I will not go and reap the succession to Maupertuis during his lifetime. I am overlooked by government, just as so many others by Providence; persecuted as much as anybody can be, if some day I have to fly my country, I will simply ask Frederick’s permission to go and die in his dominions, free and poor.”
Frederick II. gave D’Alembert a pension; it had but lately been Louis XIV. who thus lavished kindnesses on foreign scholars: he made an offer to the Encyclopaedists to go and finish their vast undertaking at Berlin. Catherine II. made the same offers, asking D’Alembert, besides, to take charge of the education of her son. “I know your honesty too well,” she wrote, “to attribute your refusals to vanity; I know that the cause is merely love of repose in order to cultivate literature and friendship. But what is to prevent your coming with all your friends? I promise you and them too all the comforts and every facility that may depend upon me; and perchance you will find more freedom and repose than you have at home. You do not yield to the entreaties of the King of Prussia, and to the gratitude you owe him, it is true, but then he has no son. I confess that I have my son’s education so much at heart, and that you are so necessary to me, that perhaps I press you too much. Pardon my indiscretion for the reason’s sake, and rest assured that it is esteem which has made me so selfish.”