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

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.

And let no one suppose that I claim that just living can be taught for, in a word, I hold that there does not exist an art of the kind which can implant sobriety and justice into depraved natures. Nevertheless, I do think that the study of political discourse can help more than any other thing to stimulate and form such qualities of character

Whetstones are not themselves able to cut, but make iron sharp and capable of cutting.

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

Abhor flatterers as you would deceivers; for both, if trusted, injure those who trust them. If you admit as friends men who seek your favor for the lowest ends, your life will be lacking in friends who will risk your displeasure for the highest good.