We must observe a right standard between too great mildness and excessive harshness. They who endeavour to creep into the hearts of others by a false show of mildness gain nothing substantial or lasting. This the example of Absalom plainly enough shows.
112. Moreover, due measure befits even our words and instructions, that it may not seem as though there was either too great mildness or too much harshness. Many prefer to be too mild, so as to appear to be good. But it is certain that nothing feigned or false can bear the form of true virtue; nay, it cannot even last. At first it flourishes, then, as time goes on, like a floweret it fades and passes away, but what is true and sincere has a deep root.
113. To prove by examples our assertion that what is feigned cannot last, but flourishing just for a time quickly fails, we will take one example of pretence and falsehood from that family, from which we have already drawn so many examples to show their growth in virtue.
114. Absalom was King David's son, known for his beauty, of splendid appearance and in the heyday of youth; so that no other such man as he was found in Israel. He was without a blemish from the sole of his foot to the crown of his head. He had for himself a chariot and horses and fifty men to run before him. He rose at early dawn and stood before the gate in the way, and whoever he knew to be seeking the judgment of the king, he called to himself, saying: “From what city are you?” And he answered: “I your servant am of one of the tribes of Israel.” And Absalom answered: “Your words are good and right. Is there none given you by the king to hear you? Who will make me a judge? And whosoever will come unto me, that has need of judgment, I will give him justice.” With such words he cajoled them. And when they came to make obeisance to him, stretching forth his hand he took hold of them and kissed them. So he turned the hearts of all to himself. For flattery of this sort quickly finds its way to touch the very depths of the heart.
115. Those spoilt and ambitious men chose what for a time seemed an honour to them, and was pleasing and enjoyable. But while that delay took place, which the prophet, being prudent above all, thought ought to intervene, they could no longer hold out or bear it. Then David having no doubt about the victory commended his son to those who went out to fight, so that they should spare him. He would not engage in the battle himself lest he should seem to be taking up arms against one who was still his son, though attempting to destroy his father.
116. It is clear, then, that those things are lasting and sound, which are true and grow out of a sincere and not a false heart. Those, however, which are brought about by pretence and adulation can never last for long.
Source: On the Duties of the Clergy (New Advent)