Indian wolf story

I found this story once i was searching about native Americans. Its really really touching.

An old Indian is sitting at the fire place with his grand-son. It had become dark and the only sound you could hear was the crackling of the fire. After a while of silence the old man says: "Do you know how I feel sometimes? It's like there are two wolves in my heart, fighting against each other. The one is revengeful, aggressive and evil. The other one is loving, soft and caring." "Which one will win the fight?" the boy asks. And the old man says: "The one that I feed."