I think the existence of zombies would contradict certain laws of nature in our world. It seems to be a law of nature, in our world, that when you get a brain of a certain character you get consciousness going along with it.
[The writer] must essentially draw from life as he sees it, lives it, overhears it or steals it, and the truer the writer, perhaps the bigger the blackguard. He lives by biting the hand that feeds him.