A sound principle, I think, is this. In the friendship of upright men there ought to be an unrestricted communication of every interest, every purpose, every inclination. Then, in any matter of importance to the life or reputation of your friend, you may deviate a little from the strictest line of conduct so long as you do not do anything that is actually infamous. Then, with regard to the choice of friends, Scipio used to say that men were more careful about their sheep and goats than about their friends. Choose men of constancy, solidity, and firmness; and until their trustworthiness has been tested, be moderate in your affection and confidence. Seek first of all for sincerity. Your friend should also have an open, genial, and sociable temper, and his sympathies should be the same as yours. He must not be ready to believe accusations. Lastly, his talk and manner should be debonair; we don't want austerities and solemnities in friendship. I have heard it suggested that we ought perhaps to prefer new friends to old, as we prefer a young horse to an old one. Satiety should have no place in friendship. Old wines are the best, and so are the friends of many years. Do not despise the acquaintance that promises to ripen into something better; but do not sacrifice for it the deeply rooted intimacy. Even inanimate things take hold of our hearts by long custom; we love the mountains and forests of our youth. There is often a great disparity in respect of rank or talent between intimate friends. Whenever that is so, let the superior place himself on the level of the inferior; let him share all his advantages with his friend. The best way to reap the full harvest of genius, or of merit, or of any other excellence, is to encourage all one's kindred and associates to enjoy it too. But if the superior ought to condescend to the inferior, so the inferior ought to be free from envy. And let him not make a fuss about such services as he has been able to render.