23. With this much said, within the necessary brevity of this kind of treatise, as to what we need to know about the causes of good and evil-enough to lead us in the way toward the Kingdom, where there will be life without death, truth without error, happiness without anxiety-we ought not to doubt in any way that the cause of everything pertaining to our good is nothing other than the bountiful goodness of God himself. The cause of evil is the defection of the will of a being who is mutably good from the Good which is immutable. This happened first in the case of the angels and, afterward, that of man.
24. This was the primal lapse of the rational creature, that is, his first privation of the good. In train of this there crept in, even without his willing it, ignorance of the right things to do and also an appetite for noxious things. And these brought along with them, as their companions, error and misery. When these two evils are felt to be imminent, the soul's motion in flight from them is called fear. Moreover, as the soul's appetites are satisfied by things harmful or at least inane-and as it fails to recognize the error of its ways-it falls victim to unwholesome pleasures or may even be exhilarated by vain joys. From these tainted springs of action-moved by the lash of appetite rather than a feeling of plenty-there flows out every kind of misery which is now the lot of rational natures.
25. Yet such a nature, even in its evil state, could not lose its appetite for blessedness. There are the evils that both men and angels have in common, for whose wickedness God hath condemned them in simple justice. But man has a unique penalty as well: he is also punished by the death of the body. God had indeed threatened man with death as penalty if he should sin. He endowed him with freedom of the will in order that he might rule him by rational command and deter him by the threat of death. He even placed him in the happiness of paradise in a sheltered nook of life [in umbra vitae] where, by being a good steward of righteousness, he would rise to better things.
26. From this state, after he had sinned, man was banished, and through his sin he subjected his descendants to the punishment of sin and damnation, for he had radically corrupted them, in himself, by his sinning. As a consequence of this, all those descended from him and his wife (who had prompted him to sin and who was condemned along with him at the same time)-all those born through carnal lust, on whom the same penalty is visited as for disobedience-all these entered into the inheritance of original sin. Through this involvement they were led, through divers errors and sufferings (along with the rebel angels, their corruptors and possessors and companions), to that final stage of punishment without end. "Thus by one man, sin entered into the world and death through sin; and thus death came upon all men, since all men have sinned."  By "the world" in this passage the apostle is, of course, referring to the whole human race.
27. This, then, was the situation: the whole mass of the human race stood condemned, lying ruined and wallowing in evil, being plunged from evil into evil and, having joined causes with the angels who had sinned, it was paying the fully deserved penalty for impious desertion. Certainly the anger of God rests, in full justice, on the deeds that the wicked do freely in blind and unbridled lust; and it is manifest in whatever penalties they are called on to suffer, both openly and secretly. Yet the Creator's goodness does not cease to sustain life and vitality even in the evil angels, for were this sustenance withdrawn, they would simply cease to exist. As for mankind, although born of a corrupted and condemned stock, he still retains the power to form and animate his seed, to direct his members in their temporal order, to enliven his senses in their spatial relations, and to provide bodily nourishment. For God judged it better to bring good out of evil than not to permit any evil to exist. And if he had willed that there should be no reformation in the case of men, as there is none for the wicked angels, would it not have been just if the nature that deserted God and, through the evil use of his powers, trampled and transgressed the precepts of his Creator, which could have been easily kept-the same creature who stubbornly turned away from His Light and violated the image of the Creator in himself, who had in the evil use of his free will broken away from the wholesome discipline of God's law-would it not have been just if such a being had been abandoned by God wholly and forever and laid under the everlasting punishment which he deserved? Clearly God would have done this if he were only just and not also merciful and if he had not willed to show far more striking evidence of his mercy by pardoning some who were unworthy of it.