To Florus 5.26

But enough has been said against these absurdities. Let us come to the exceedingly tangled question I mentioned above, whose subtlety deceived your teacher himself. You tried to meet our objection not by explaining it but by putting forward another, more difficult one. I had taught that in adults who work evil by their own will, nature’s innocent beginnings are praised while the deviations of their actions are rightly blamed. There are two things, therefore, to which opposite judgments can apply. In infants, however, there is only one thing, nature, since there is no will. That one thing must be reckoned either to God or to the demon. I concluded that, if nature exists through God, original evil cannot be within it; but if nature is transferred to the devil through inborn evil, nothing remains by which the human being can be vindicated as God’s work. When you reached these passages, you replied with your usual good faith that my conclusion was true, but that infants too have two things: nature and sin. Yet sin, to recall the previous definitions, is nothing other than the will to retain or commit what justice forbids and from which one is free to abstain. With sin thus established as nothing other than the choice of an evil will, you replied, Epicurus of our age, that infants possess sin but no will. How disgraceful that is, the fourth book has already shown.

In these passages I said, ‘If sin comes from will, the will producing sin is evil; if from nature, the nature producing sin is evil.’ You tried to confront me with a question plainly not invented by you. Some years ago, when we were in Carthage, a certain Honoratus, a friend of yours and equally a Manichaean—as your letters indicate—put this same question to me. I mention this only to make clear that this is the question which deceived Mani and Marcion so many centuries ago. Against my statement, ‘If sin lies in nature, the nature producing sin is evil,’ you speak as follows:

‘I ask him to answer if he can. Just as plainly all evil deeds arise as fruits from an evil will as from an evil tree, so whence does he say the evil will itself arose—the evil tree bearing evil fruits? If from an angel, what was that angel but God’s good work? If from a human being, what was that human being but God’s good work? Rather, since the angel’s evil will arose from the angel, and the human being’s from the human being, what were these two before those evils arose within them, except God’s good work and a good and praiseworthy nature? See, then: evil arises from good, and there was absolutely nothing from which it could arise except good. I mean the evil will itself, preceded by no evil—not evil works, which arise only from an evil will as from an evil tree. Yet the evil will could arise from good not because the good was made by the good God, but because it was made from nothing, not from God. Why, then, does he say: “If nature is God’s work, the devil’s work is not permitted to pass through God’s work”? Did not the devil’s work, when it first arose in the angel who became the devil, arise in God’s work? Therefore, if an evil that existed nowhere could arise in God’s work, why could an evil already existing somewhere not pass through God’s work? Are human beings not God’s work? Sin therefore passed through human beings—that is, the devil’s work through God’s work. To say the same thing another way: the work of God’s work through God’s work’ (Augustine, Marriage and Desire 2.28.48).

These many words I have quoted from you have fully disclosed the very head and fountain of the ancient error. You have offered nothing sharper in your statements, nothing more intricate in argument. Driven across the whole field of debate, and expelled by hostile truth’s weapons from every place where you tried to stand, you have at last reached the cave Mani dug among the shadows of difficult questions. You testified to this question’s difficulty by saying, ‘I ask him to answer if he can.’ Since we both agree that the point is difficult, I urge the reader to attend with his whole mind. Let him follow the distinctions, subtle as the matter requires—distinctions which I trust Christ’s help will make substantial—first attentively and then confidently. You asked, then, where evil comes from. I ask what evil you mean, since this name is shared by guilt and punishment. Punishment, however, is called evil only in an extended sense, since the gravity of the judgment imposing it justifies it. You reply that you mean sin, not punishment.