Reprove thy friend privately; commend him publicly. - Solon
Think not those faithful who praise all thy words and actions; but those who kindly reprove thy faults. - Socrates
To reprove small faults within due vehemence, is as absurd as if a man should take a great hammer to kill a fly on his friend's forehead.
Money can't buy love, but money can reprove one's care, especially when there is little to give in its efforts to help. - Anthony Liccione
Praise your children openly, reprove them secretly. - William Cecil