But though the spirit still triumphed at moments over the body, the end was near. When her misery was dulled by opium, d’Alembert was always watching, unheeded, at her bedside. It was the attitude of his life. When she became conscious, he was there still. Before she died, she asked his pardon; but de Guibert’s was the last name upon her lips. She died on May 23, 1776, not yet forty-five years old.
D’Alembert’s grief seems to have taken by surprise many short-sighted friends who had supposed that quiet exterior to hide a cold, or an unawakened, heart. He was utterly crushed and broken. His life had lost at once its inspiration and its meaning. For the sake of Mademoiselle he had grown old without family and without hope. His friends, in that age of noble friendships, did their best to comfort him. But his wounds were deeper than they knew. With a super-refinement of selfishness or cruelty, Mademoiselle had left him her Correspondence. She had not preserved in it one single line of the many letters he had himself written to her, while it contained full and certain proofs of her double infidelity.
He who has lost only those of whose faith and truth he is sure, has not yet reached the depth of human desolation.
After a while, d’Alembert tried to return to his first affection—that cold but faithful mistress, his mathematical studies. At the Academy he pronounced the éloge of Louis de Sacy, who had been the lover of the Marquise de Lambert. For the first time he looked into his heart and wrote, and thus for the first time he touched the hearts of others; the cold style took fire, and beneath the clumsy periods welled tears.
But the writer was consumed to the soul with grief and weariness. This was not the man who could use sorrow as a spur to new endeavour and to nobler work. Before the persecutions which had assailed the Encyclopædia he had bowed his head and taken covert, and the death of his mistress broke not only his heart, but his spirit and his life. From Madame Marmontel and from Thomas, he derived, it is said, some sort of comfort: Condorcet was as a son; but with Mademoiselle’s death the light of her society had gone out. The friends who remained were but pale stars in a dark sky. D’Alembert was growing old. He suffered from a cruel disease and could not face the horrors of the operation which might have relieved it. ‘Those are fortunate who have courage,’ said he; ‘for myself, I have none.’ It was life, not death, he dreaded. What use then to suffer only to prolong suffering?
The mental enlightenment he had given the world, the wider knowledge which he had lived to impart, consoled this dying thinker scarcely at all. He was to his last hour what he had been when Mademoiselle took ill-fated compassion on his dependence and loneliness—a child, affectionate, solitary, tractable, with the great mind always weighed down by the supersensitiveness of a child’s heart and with a child’s clinging need of care and tenderness. He died on October 29, 1783.
The man whose only reason for dreading poverty had been lest he should be forced to reduce his charities, left, as might have been expected, a very small fortune. Condorcet was his residuary legatee, and made his éloge in both the Academies.
Diderot himself was dying when he heard of his old friend’s death. ‘A great light has gone out,’ said he. Euler, d’Alembert’s brother, and sometimes his rival, geometrician, survived him only a few months. And Voltaire, the quick and life-giving spirit of the vast movement of which d’Alembert was the Logic, the Reason, the Thought, had already died to earth, though he lived to everlasting fame.
D’Alembert owes his greatest reputation to geometry. But, as Grimm said, in that department only geometricians can exactly render him his due: ‘He added to the discoveries of the Eulers ... and the Newtons.’ To the general public his great title to glory lies in the mighty help he gave to that great monument of Voltairian philosophy, the Encyclopædia. The Preface was ‘a work for which he had no model.’ By it, he introduced to the world that book which Diderot produced, and which, except the Bible and the Koran, may be justly said to have been the most influential book in history; which gave France, and, through France, Europe, that new light and knowledge which brought with them a nobler civilisation and a recognition of the universal rights of man.
In himself, d’Alembert was always rather a great intelligence than a great character. To the magnificence of the one he owed all that has made him immortal, and to the weakness of the other the sorrows and the failures of his life. For it is by character and not by intellect the world is won.