You must be frank with the world; frankness is the child of honesty and courage. Say just what you mean to do on every occasion, and take it for granted you mean to do right … Never do anything wrong to make a friend or keep one; the man who requires you to do so, is dearly purchased at a sacrifice. Deal kindly, but firmly with all your classmates; you will find it the policy which wears best. Above all do not appear to others what you are not.

As quoted in Extraordinary Lives : The Art and Craft of American Biography (1986) by Robert A. Caro and William Knowlton Zinsser. Also quoted in Truman by David McCullough (1992), p. 44, New York: Simon & Schuster.-