History has concerned itself much less with Madame Rousseau than with Madame de Tencin. Yet it was the glazier’s wife who was d’Alembert’s real mother after all. If she was low-born and ignorant, she had yet the happiest of all acquirements—she knew how to win love and to keep it. The great d’Alembert, universally acclaimed as one of the first intellects of Europe, had ever for this simple person, who defined a philosopher as ‘a fool who torments himself during his life that people may talk of him when he is dead,’ the tender reverence which true greatness, and only true greatness perhaps, can bear towards homely goodness. From her he learnt the blessing of peace and obscurity. From his association with her he learnt his noble idea—difficult in any age, but in that age of degrading luxury and self-indulgence well nigh impossible—that it is sinful to enjoy superfluities while other men want necessaries. His hidden life in the dark attic above her husband’s shop made it possible for him to do that life’s work. For nearly half a century he knew no other home. When he left her roof at last, in obedience to the voice of the most masterful of all human passions, he still retained for her the tenderest affection, and bestowed upon her and her grandchildren the kindness of one of the kindest hearts that ever beautified a great intelligence.
Little Jean Baptiste was put to a school in the Faubourg Saint-Antoine, where he passed as Madame Rousseau’s son. General Destouches paid the expenses of this schooling, took a keen pleasure in the child’s brightness and precocity, and came often to see him. One day he persuaded Madame de Tencin to accompany him. The seven-year-old Jean Baptiste remembered that scene all his life. ‘Confess, Madame,’ says Destouches, when they had listened to the boy’s clever answers to his master’s questions, ‘that it was a pity to abandon such a child.’ Madame rose at once. ‘Let us go. I see it is going to be very uncomfortable for me here.’ She never came again.
Destouches died in 1726, when his son was nine years old. He left the boy twelve hundred livres, and commended him to the care of his relatives. Through them, at the age of twelve, Jean Baptiste received the great favour of being admitted to the College of the Four Nations, founded by Mazarin, and in 1729 the most exclusive school in France. Fortunately for its new scholar it was something besides fashionable, and did its best to satisfy his extraordinary thirst for knowledge. His teachers were all priests and Jansenists, and nourished their apt scholar on Jansenist literature, imbuing him with the fashionable theories of Descartes. How soon was it that they began to hope and dream that in the gentle student called Lerond, living on a narrow pittance above a tradesman’s shop, they had found a new Pascal, a mighty enemy of the Archfiend Jesuitism?
But beneath his timid and modest exterior there lay already an intellect of marvellous strength and clearness, a relentless logic that tested and weighed every principle instilled in him, every theory masquerading as a fact. He quickly became equally hostile to both Jesuit and Jansenist. It was at school that he learnt to hate with an undying hatred, religion—the religion that in forty years launched, on account of the Bull Unigenitus, forty thousand lettres de cachet, that made men forget not only their Christianity but their humanity, and give themselves over body and soul to the devouring fever called fanaticism. At school also he conceived his passion for mathematics, that love of exact truth which no Jansenist priest, however subtle, could make him regard as a dangerous error.
When he was eighteen, in 1735, he took his degree of Bachelor of Arts and changed his name. D’Alembert is thought to be an anagram on Baptiste Lerond. Anagrams were fashionable, and one Arouet, who had elected to be called Voltaire, had made such an alteration of good omen. D’Alembert went on studying at the College, but throughout his studies mathematics were wooing him from all other pursuits. The taste, however, was so unlucrative, and the income from twelve hundred livres so small, that a profession became a necessity. The young man conscientiously qualified for a barrister. But ‘he loved only good causes’ and was naturally shy. He never appeared at the Bar.
Then he bethought him of medicine. He would be a doctor! But again and again the siren voice of his dominant taste called him back to her. His friends—those omniscient friends always ready to put a spoke in the wheel of genius—entreated him to be practical, to remember his poverty, and to make haste to grow rich. He yielded to them so far that one day he carried all his geometrical books to one of their houses, and went back to the garret at Madame Rousseau’s to study medicine and nothing else in the world. But the geometrical problems disturbed his sleep.
—— One master-passion in the breast,
Like Aaron’s serpent, swallowed all the rest.
Fate wanted d’Alembert, the great mathematician, not some prosperous, unproductive mediocrity of a Paris apothecary. The crowning blessing of life, to be born with a bias to some pursuit, was this man’s to the full.
He yielded to Nature and to God. He brought back the books he had abandoned, flung aside those for which he had neither taste nor aptitude, and at twenty gave himself to the work for which he had been created.
Some artist should put on canvas the picture of this student, sitting in his ill-aired garret with its narrow prospect of ‘three ells of sky,’ poor, delicate, obscure—or rich, rather, in the purest of earthly enjoyments, the pursuit of truth for its own sake. He could not afford to buy many of the books he needed, so he borrowed them from public libraries. He left the work of the day anticipating with joy the work of the morrow. For the world he cared nothing, and of him it knew nothing. Fame?—he did not want it. Wealth?—he could do without it. Poor as he was, there was no time when he even thought of taking pupils, or using the leisure he needed for study in making money by a professorship.