An old Cherokee told his grandson, "My son, there is a battle between two wolves inside us all. One is Evil. It is anger, jealousy, greed, resentment, inferiority, lies, and ego. The other is Good. It is joy, peace, love, hope, humility, kindness, empathy, and truth."
The boy thought about it, and asked, "Grandfather, which wolf wins?"
The old man quietly replied, "The one you feed."
(saw this on a forum and saw it related various places online, as a "Native American Proverb". I know nothing else of the source. It just kind of appealed).