To Nicocles (27-28)

Do not give your friendship to everyone who desires it, but only to those who are worthy of you; not to those whose society you will most enjoy, but to those with whose help you will best govern the state. Subject your associates to the most searching tests, knowing that all who are not in close touch with you will think that you are like those with whom you live. When you put men in charge of affairs which are not under your personal direction, be governed by the knowledge that you yourself will be held responsible for whatever they do.

Regard as your most faithful friends, not those who praise everything you say or do, but those who criticize your mistakes. Grant freedom of speech to those who have good judgement, in order that when you are in doubt you may have friends who will help you to decide. Distinguish between those who artfully flatter and those who loyally serve you, that the base may not fare better than the good. Listen to what men say about each other and try to discern at the same time the character of those who speak and of those about whom they speak.