12 If the next difficulty in the mind of the inquirer arose from the divisions and heresies among those called Christians, he would learn that this too is taken notice of by the prophets. For, as if it was natural that, after being satisfied about the blindness of the Jews, this objection from the divisions among Christians should occur, Jeremiah, observing this order in his prophecy, immediately adds in the passage already quoted: "The partridge is clamorous, gathering what it has not brought forth, making riches without judgment."
For the partridge is notoriously quarrelsome, and is often caught from its eagerness in quarreling. So the heretics discuss not to find the truth, but with a dogged determination to gain the victory one way or another, that they may gather, as the prophet says, what they have not brought forth. For those whom they lead astray are Christians already born of the gospel, whom the Christian profession of the heretics misleads. Thus they make riches not with judgment, but with inconsiderate haste.
For they do not consider that the followers whom they gather as their riches are taken from the genuine original Christian society, and deprived of its benefits; and as the apostle describes these heretics in the words: "As Jannes and Jambres withstood Moses, so they also resist the truth: men of corrupt minds, reprobate concerning the faith. But they shall proceed no further: for their folly shall be manifest to all men, as theirs also was." So the prophet goes on to say of the partridge, which gathers what it has not brought forth: "In the midst of his days they shall leave him, and in the end he shall be a fool;" that is, he who at first misled people by a promising display of superior wisdom, shall be a fool, that is, shall be seen to be a fool.
He will be seen when his folly is manifest to all men, and to those to whom he was at first a wise man he will then be a fool.
Source: Reply to Faustus the Manichaean (New Advent)