Frederick II. said, like Lacenaire, that vengeance is the pleasure of the gods, and that he would die happy if he could inflict on his enemies more evils than he had suffered from them. He experienced real delight in morally tormenting his friends, sometimes beating them; if a courtier liked to pomade himself, he soaked his clothes in oil; he bargained with Voltaire over sugar and chocolate, and deprived him of his money. Donizetti treated his family brutally; it was after a fit of savage anger, in which he had beaten his wife, that he composed, sobbing, the celebrated air, _Tu che a Dio spiegasti l’ali_;[140] a remarkable instance of the double nature of personality in men of genius, and at the same time of their moral insensibility. Houssaye narrates a similar scene, in which A. Dumas was so carried away during a quarrel, as to tear out his wife’s hair. She, in despair, wished to retire to a convent; yet after some minutes he gaily wrote a comic scene, and said to his friends: “If tears were pearls, I would make myself a necklace of them.” Byron used to beat the Guiccioli, and also his Venetian mistress, the gondolier’s wife, who, however, gave him as good. Fontenelle, seeing his companion at table struck by apoplexy, was not disconcerted; he simply took advantage of the incident to change the sauce for the asparagus to vinegar; out of deference to his friend’s taste he had previously ordered butter. It is sufficient to be present at any academy, university, faculty, or gathering of men who, without genius, possess at least erudition, to perceive at once that their dominant thought is always disdain and hate of the man who possesses, almost or entirely, the quality of genius. The man of genius, in his turn, has nothing but contempt for others. He believes he has all the more right to laugh at others, from being himself sensitive to the slightest criticism; he is even offended at praise given to another as blame directed to himself. That is why at academical gatherings the greatest men only agree in praising the most ignorant person. We have seen that Chateaubriand was offended when his shoemaker was praised. Lisfranc called his colleague, Dupuytren, a brigand, and Roux and Velpeau forgers. I have been able to observe men of genius when they had scarcely reached the age of puberty: they did not manifest the deep aversions of moral insanity, but I have noted among all a strange apathy for everything which does not concern them; as though plunged in the hypnotic condition, they did not perceive the troubles of others, or even the most pressing needs of those who were dearest to them; if they observed them, they grew tender, and even at once hastened to attend to them; but it was a fire of straw, soon extinguished, and it gave place to indifference and weariness. Genius, said Schopenhauer, is solitary. Genius, wrote Goethe, is only related to its time by its defects.