18. And it was made clear unto me that those things are good which yet are corrupted, which, neither were they supremely good, nor unless they were good, could be corrupted; because if supremely good, they were incorruptible, and if not good at all, there was nothing in them to be corrupted. For corruption harms, but, less it could diminish goodness, it could not harm. Either, then, corruption harms not, which cannot be; or, what is most certain, all which is corrupted is deprived of good. But if they be deprived of all good, they will cease to be. For if they be, and cannot be at all corrupted, they will become better, because they shall remain incorruptibly. And what more monstrous than to assert that those things which have lost all their goodness are made better? Therefore, if they shall be deprived of all good, they shall no longer be. So long, therefore, as they are, they are good; therefore whatsoever is, is good. That evil, then, which I sought whence it was, is not any substance; for were it a substance, it would be good. For either it would be an incorruptible substance, and so a chief good, or a corruptible substance, which unless it were good it could not be corrupted. I perceived, therefore, and it was made clear to me, that Thou didst make all things good, nor is there any substance at all that was not made by Thee; and because all that Thou hast made are not equal, therefore all things are; because individually they are good, and altogether very good, because our God made all things very good.
Reproduced in full. Translation: Nicene and Post-Nicene Fathers, series 1, vol. 1 (Schaff, 1886), public domain (Public domain).