This part is alive in most people, at least to some degree. True, everyone is selfish at times. Everyone is vain and egocentric to some extent. But in most people, there is a line that this part commands us not to cross. It tells us that we can go only so far in the way we treat other people, only so far in the way we damage them. It may be that this "part” is no more than a chemical trace or a configuration of brain cells. We call it "conscience," "being human," or "having a heart."
