People like people because they like one another. And people don't trust one another thoroughly like an animal and a human being. I can know you very well. But when I turn my back, I don't know you. Not truly. But my little dog... I can turn my back on my little dog and I know he's back there. He's my little friend. He's not gonna jump on me or bite me or anything like that. But human beings cannot be this way.

- Taken from Errol Morris' Gates of Heaven.