To Florus 1.16
Since, then, it is established that these things were carried out just as I have said, I cannot sufficiently wonder at the man's shamelessness. In his recent work he accuses my books of falsehood, although he admits that they have not yet reached his hands (Augustine, On Marriage and Concupiscence 2.2). It is a dreadful thing that the habit of sinning produces a love of wrongdoing, but more dreadful still that it extinguishes shame. Although it was already clear that this comes from the practice of wickedness, our present dangers have taught us more about it than any of us could have supposed. When could I have believed that this Numidian's forehead had grown so brazen that in one work, indeed in one sentence, he would admit both that I had spoken falsely and that he had not read what I said?