It is in the activities of men that the evils appear, and that not of all men nor always. And as to these, if men sinned for the sake of evil, nature itself would be evil. But if the adulterer thinks his adultery bad but his pleasure good, and the murderer thinks the murder bad but the money he gets by it good, and the man who does evil to an enemy thinks that to do evil is bad but to punish his enemy good, and if the soul commits all its sins in that way, then the evils are done for the sake of goodness. (In the same way, because in a given place light does not exist, there comes darkness, which has no positive existence.) The soul sins therefore because, while aiming at good, it makes mistakes about the good, because it is not primary essence. And we see many things done by the Gods to prevent it from making mistakes and to heal it when it has made them. Arts and sciences, curses and prayers, sacrifices and initiations, laws and constitutions, judgments and punishments, all came into existence for the sake of preventing souls from sinning; and when they are gone forth from the body, Gods and spirits of purification cleanse them of their sins.