As small letters hurt the sight, so do small matters him that is too much intent upon them; they vex and stir up anger, which begets an evil habit in him in reference to greater affairs.
PlutarchMan is neither by birth nor disposition a savage, nor of unsocial habits, but only becomes so by indulging in vices contrary to his nature.
PlutarchWe ought to give our friend pain if it will benefit him, but not to the extent of breaking off our friendship; but just as we make use of some biting medicine that will save and preserve the life of the patient. And so the friend, like a musician, in bringing about an improvement to what is good and expedient, sometimes slackens the chords, sometimes tightens them, and is often pleasant, but always useful.
Plutarch