The most original source I could find comes from the Nanticoke Indian Association's website where they account "The Tale of the Two Wolves."
One evening, an elderly Cherokee brave told his grandson about a battle that goes on inside people. He said, "My son, the battle is between two 'wolves' inside us all. One is evil. It is anger, envy, jealousy, sorrow, regret, greed, arrogance, self-pity, guilt, resentment, inferiority, lies, false pride, superiority, and ego. The other is good. It is joy, peace, love, hope, serenity, humility, kindness, benevolence, empathy, generosity, truth, compassion, and faith." The grandson thought about it for a minute and then asked his grandfather, "Which wolf wins?"
The grandfather simply replied, "The one that you feed."
I want to feed the good wolf.
I hear the tale last night in this concise form: The two wolves of joy and despair fight inside of us each day. Which one wins?
The one I feed.
I feed joy today.