When not to make a fraternal correction: "But if thy brother shall offend against thee, go, and rebuke him between thee and him alone."

Continuation of the Holy Gospel according to Matthew
Matt 18:15-22
At that time, Jesus saith to his disciples: But if thy brother shall offend against thee, go, and rebuke him between thee and him alone.  And so on.

Homily by St. Augustine, Bishop of Hippo.
16th Sermon on the Words of the Lord, vol. x.
Why tell him his fault? Because he hath made thee smart by trespassing against thee? God forbid. If thou tell him his fault because thou lovest thyself, thou dost nothing. But if thou tell it him because thou lovest him, then dost thou do exceeding well. Hear now, in the words of the Gospel itself, for love of whom, thou oughtest to do it, of thyself, or of him. The Lord saith: If he shall hear thee, thou hast gained thy brother. Therefore it behoveth thee to do it for his sake, that thou mayest gain him; since, if thou so do, haply thou mayest gain him; whereas, if thou do it not, he may haply perish. Why then are there so many who reckon lightly of a trespass against their brother, and say I have done no great offence, for I have trespassed only against my fellow man? Deem it not light; thou hast trespassed, though it be against thy fellow man.