Neither Society nor History would ever have known him, nor have detected any talent in him, had it not been his fortune to dispossess his two great contemporaries, Voltaire and Rousseau, successively of their mistresses, conquering the heart, first of Madame du Châtelet, and later that of Madame de Houdetot. Madame de Houdetot and he turned out to be really congenial spirits. For Madame du Châtelet his own conduct shows that he did not really care--as how could a young man of thirty-one for a woman of forty-two or else forty-seven, who had been some years a grandmother? Her letters are full of impassioned professions of affection, impatient longings for his presence, reproaches for his indifference. On his side it was all a question of vanity. It flattered him to think that he had eclipsed the great genius of the age in the affections of a woman of whom all the polite world was talking. What she was he knew well enough. More than once had she tasted of the forbidden fruit. Voltaire's _Epître à la Calomnie_ had not whitewashed the Magdalen who had had relations successively with Guébriant, with Richelieu, and with Voltaire. Of Voltaire's overstrained praise of her assumed modesty Saint Lambert himself writes:-- De cette tendre Courtisane Il faisait presque une Susanne. But what could have induced Madame du Châtelet to engage in this conspiracy of deceit all round--deceit on her part towards Voltaire, deceit on Saint Lambert's part towards both Voltaire (with whom he was not then on terms of intimacy) and Madame de Boufflers (with whom he had a standing _liaison_)? It was in Madame de Boufflers' drawing-room, of all places, that the courtship was most actively carried on. Her gilt-framed harp, we hear, served as a letter-box for the lovers. There was a slit in it just of a convenient size to hold the letters, which passed daily. Of Madame du Châtelet's passion there could be no doubt. She threw herself into the _amour_ with the fervour of a girl of sixteen. She sent her lover dainty _billets-doux_ written on pink and blue-edged, fringed, and scented paper; declared that she could not live two days without hearing from him, when he was away; appointed _rendez-vous_ in the "Bosquet"--watched and waited for him. It seems ridiculous in a grandmother; but she was not the first woman of her age to go wrong.