Consider that nothing in human life is stable; for then you will not exult overmuch in prosperity, nor grieve overmuch in adversity. Rejoice over the good things which come to you, but grieve in moderation over the evils which befall you.

Make no man your friend before inquiring how he has used his former friends; for you must expect him to treat you as he has treated them. Be slow to give your friendship, but when you have given it, strive to make it lasting; for it is as reprehensible to make many changes in one's associates as to have no friends at all. Neither test your friends to your own injury nor be willing to forego a test of your companions.

So far has Athens left the rest of mankind behind in thought and expression that her pupils have become the teachers of the world, and she has made the name of Hellas distinctive no longer of race but of intellect, and the title of Hellene a badge of education rather than of common descent.

Conduct yourself towards your parents as you would have your children conduct themselves towards you.

Be gracious to all men, but choose the best to be your friends.

But I marvel when I observe these men setting themselves up as instructors of youth who cannot see that they are applying the analogy of an art with hard and fast rules to a creative process

Regard as your most faithful friends, not those who praise everything you say or do, but those who criticize your mistakes.