"There are several good protections against temptations, but the surest is cowardise."
- Mark Twain, Following the Equator: A Journey Around the World

"[D]on't grow old. With age comes caution, which is another name for cowardice.... Whatever else you do in life, don't cultivate a conscience. Without a conscience a man may never be said to grow old. This is an age of very old men."
- Herbert Beerbohm Tree