To Florus 3.138

[Augustine writes:] ‘Listen briefly, then, to what this question involves. Catholics say that the good Creator God made human nature good, but, corrupted by sin, it needs Christ the physician. Manichaeans say human nature was not made good by God and then corrupted by sin. Rather, the prince of eternal darkness created humanity by mixing two natures that always existed, one good and the other evil. Caelestians and Pelagians say the good God made human nature good, but it is so healthy in newborn infants that at that age they do not need Christ’s medicine. Recognize, then, your own name in your doctrine, and stop charging the catholics who refute you with someone else’s doctrine and name. Truth refutes both the Manichaeans and you.

‘For it says to the Manichaeans: “Have you not read that the one who made humankind from the beginning made them male and female? For this reason a man shall leave father and mother and cling to his wife, and the two shall be one flesh. So they are no longer two but one flesh. Therefore what God has joined, let no human separate” (Matthew 19:4–6). Thus it shows that God both creates human beings and joins spouses, against the Manichaeans who deny both.

‘To you, however, it says: “The Son of Man came to seek and save what was lost” (Luke 19:10). But you, excellent Christians, answer Christ: If you came to seek and save what was lost, you did not come to infants; they were not lost and were born safe. Go to older people. We lay down the rule for you from your own words: “The healthy do not need a physician, but the sick do” (Matthew 9:12).

‘Thus the Manichaean, who says an evil nature is mixed into humanity, at least wants the good soul saved from it by Christ. You, however, maintain that in infants, when their bodies are sound, Christ has nothing to save. Accordingly the Manichaean blames human nature in a detestable way, but you praise it in a cruel way. Whoever believes your praise will not offer their infants to the Savior’ (Augustine, Marriage and Sexual Desire 2.9).

I pointed out even in my first work that your chief aim is to be poorly understood.