Therefore flattery is a sin. Accordingly, if a man were to wish always to speak pleasantly to others, he would exceed the mode of pleasing, and would therefore sin by excess. One may praise a person both well and ill, according as one observes or omits the due circumstances. For if while observing other due circumstances one were to wish to please a person by praising him, in order thereby to console him, or that he may strive to make progress in good, this will belong to the aforesaid virtue of friendship. Again, in like manner it is right to wish to please a man in order to foster charity, so that he may make spiritual progress therein.
Nothing hinders two vices being contrary to one another.
Wherefore even as detraction is evil, so is flattery, which is contrary thereto as regards what is said, but not directly as regards the end. Because flattery seeks to please the person flattered, whereas the detractor seeks not the displeasure of the person defamed, since at times he defames him in secret, but seeks rather his defamation. But flattery is most harmful, according to Ps. The sinner hath provoked the Lord. Therefore flattery is a most grievous sin.