For more than eight years after his final separation from Madame de Warens, Rousseau did nothing to make any one suppose him to be a man of genius. He obtained and threw up the position of secretary to the French ambassador at Venice; he supported himself as a musician and as a private secretary; he lived from hand to mouth, having as a companion one Therese Levasseur, a grotesquely illiterate maid servant, picked up at an inn. Their five children he successively took to the Foundling, losing sight of them forever. To the mother he was faithful for the most part, although not without some amorous wanderings, for many years. Up to 1749, then, when Rousseau was thirty-seven years old, he had published nothing of importance. He had, however, some acquaintance with literary men, being known merely as one of those adventurers without any settled means of existence, who may always be found in cities, and with whom Paris at this time appears to have been over-furnished. In features he was plain, in manners awkward; much given to making compliments to women, but generally displeasing to them, although at times interesting when roused to excitement. The Swiss Jean Jacques had little of the sparkling wit which the Frenchmen of his day rated very high, but he had much subtlety of observation and many ideas. He constantly applauded himself in his writings on being sensible rather than witty. In fact he was neither, but very ingenious and eloquent. In character he was self-indulgent but not luxurious, sensitive, vain, and sentimental. To this man,--if we may believe his own account, and I think in the main we may do so,--there came by a sudden flash an idea which altered his whole life, and which has materially affected millions of lives since he died. The idea was an evil seed, and it found an evil soil to grow in. The summer of 1749 was a hot one. Diderot, just rising into notice as a man of letters, had been imprisoned in the Castle of Vincennes, for his "Letter on the Blind," and his friends were allowed to come and see him. Rousseau used to visit him every other afternoon, walking the four or five miles which lie between the centre of Paris and the castle. The trees along the road were trimmed after the dreary French fashion, and gave little shade. From time to time Rousseau would stop, lie down on the grass and rest, and he had got into the habit of taking a book or a newspaper in his pocket. It was in this way that his eye happened to fall on a paragraph in the "Mercure de France," announcing that the Academy of Dijon would give a prize the next year for the best essay on the following subject: "Whether the Progress of the Arts and Sciences has tended to corrupt or to improve Morals."