Thérèse's first happiness did not last _a whole week_, as a merry ballad sadly says; the second did not last twenty-four hours. Laurent's reactions were sudden and violent, in proportion to the intensity of his enjoyment. We say his reactions, Thérèse said his _retractations_, and that was the more accurate word. He obeyed that inexorable longing which some young men feel to kill or destroy anything that arouses their passions. These cruel instincts have been observed in men of widely varying natures, and history has stigmatized them as perverse instincts; it would be more just to describe them as instincts perverted either by a disease of the brain contracted amid the surroundings in which the men in question were born, or by the impunity, fatal to the reason, which certain conditions assured them from their first steps in life. We have heard of young kings murdering fawns to which they seemed to be much attached, solely for the pleasure of seeing their entrails quiver. Men of genius, too, are kings in the environment in which they mature; indeed, they are absolute kings, who are intoxicated by their power. There are some who are tormented by the thirst for domination, and whose joy, when their domination is assured, excites them to frenzy. Such was Laurent, in whom two entirely distinct natures struggled for mastery. One would have said that two souls, having fought for the privilege of vivifying his body, were engaged in a desperate conflict to drive each other out. Between those contrary impulsions the poor wretch lost his free will, and fell exhausted every day after the victory of the angel or the demon who fought over his body. And when he analyzed himself, it seemed to him sometimes that he was reading in a book of magic, and could discern with marvellous and appalling lucidity the key to the mysterious spells of which he was the victim. "Yes," he said to Thérèse, "I am undergoing the phenomenon which the thaumaturgists called _possession_. Two spirits have acquired mastery over me. Is one of them really a good and one an evil spirit? No, I do not think so: the one who terrifies you, the sceptical, violent, frantic one, does ill only because he is not able to do good as he understands it. He would like to be calm, philosophical, playful, tolerant; _the other_ does not choose that he shall be so. He wishes to play his part of good angel; he seeks to be fervent, enthusiastic, single-hearted, devoted; and as his adversary mocks at him, denies him, and insults him, he becomes morose and cruel in his turn, so that the two angels together bring forth a demon." And Laurent said and wrote to Thérèse on this strange subject sentences no less beautiful than appalling, which seemed to be true and to add further privileges to the impunity he had apparently arrogated to himself with respect to her.