The two chief things that give a man reputation in counsel, are the opinion of his honesty, and the opinion of his wisdom; the authority of those two will persuade.
Ben JonsonNo man is so foolish but may give another good counsel sometimes; and no man is so wise, but may easily err, if he will take no others counsel but his own. But very few men are wise by their own counsel; or learned by their own teaching. For he that was only taught by himself had a fool to his master.
Ben Jonson