From a Cherokee legend:
There is a story of an old Cherokee teaching his grandson about life. "A fight is going on inside me," he said to the boy.
"It is a terrible fight, and it is between two wolves. One is evil: he is anger, self-pity, guilt, resentment, inferiority, lies, false pride, superiority, and ego."
He continued, "The other is good: he is joy, peace, love, hope, serenity, humility, kindness, benevolence, empathy, generosity, truth, compassion, and faith. The same fight is going on inside you- and inside every other person too."
The grandson thought about it for a minute and then asked his grandfather, "Which wolf will win?"
The old Cherokee simply replied, "The one you feed."