The severest test of character is not so much the ability to keep a secret as it is, when the secret is finally out, to refrain from disclosing that you knew it all along.
No one should pay attention to a man delivering a lecture or a sermon on his "philosophy of life" until he knows exactly how he treats his wife, his children, his neighbors, his friends, his subordinates, and his enemies.
The most important thing in an argument, next to being right, is to leave an escape hatch for your opponent, so that he can gracefully swing over to your side without too much apparent loss of face.