In so much firm, pleasure-loving flesh, we cannot find the merest trace of a moral nervous system. That explains the whole enigma of Casanova's subtle genius. Lucky man that he is, he has only sensuality, and lacks the first beginnings of a soul. Bound by no ties, having no fixed aim, restrained by no prudent considerations, he can move at a different tempo from his fellow mortals, who are burdened with moral scruples, who aim at an ethical goal, who are tied by notions of social responsibility. That is the secret of his unique impetus, of his incomparable energy.