It is not work that kills men; it is worry. Work is healthy; you can hard put more upon a man than he can bear. Worry is rust upon the blade. It is not the revolution that destroys the machinery, but the friction.
It is one of the severest tests of friendship to tell your friend his faults. So to love a man that you cannot bear to see a stain upon him, and to speak painful truth through loving words, that is friendship.