To Florus 3.144
A little later you add: ‘Human nature, whether born from marriage or adultery, is God’s work. If it were evil, it should not be generated; if it had no evil, it should not be regenerated. To sum up both points in one word: if human nature were evil, it ought not to be saved; if no evil were within it, it would not need to be saved. Whoever says it is not good denies a good Creator to the nature that was created. Whoever denies it contains evil begrudges a merciful Savior to the nature that was corrupted. Therefore, in the birth of human beings, adultery must not be excused because of the good created from it by the good Creator; nor must marriage be condemned because of the evil that the merciful Savior must heal there’ (Augustine, Marriage and Sexual Desire 2.36).
I have quoted these many passages from your writings, in which you endured great labor of thought to seem to say something clever. In keeping with our practice of using no tricks, and in confidence in the truth, they ought to be distinguished through our restatement, because your words are scarcely intelligible. You said, then, that the Manichaeans condemn flesh’s nature and maintain that humanity was made by mixing two natures, one good and the other evil. You said that we, whom you call heretics, say human nature was made by the good God and is good on its maker’s testimony, but is so healthy in infants that they do not need Christ’s medicine. Your own claim is that Adam’s nature was once good, made by the good God, but was corrupted by sin and therefore needs Christ’s medicine.
In the first book of this work I set your opinions beside the Manichaeans’ and showed that your faith differed in no way from their irreverence, from which it clearly sprang. There it appeared that fear unites you with Jovinian, but love wholly unites you with Mani. We must discuss this in the present context too, but first I distinguish our views, then yours. You correctly said we maintain that the good God made human nature good. But only this much is ours. You either failed to notice or suppressed one part needed to complete our position and inserted another of your own that is not ours. For we do not merely say God made human nature good in Adam. We say that in all infants it is created good by the same God who made that first human being. That is why we affirm that he creates all people.