Do you know, the only people I can have a conversation with are the Jews? At least when they quote scripture at you they are not merely repeating something some priest has babbled in their ear. They have the great merit of disagreeing with nearly everything I say. In fact, they disagree with almost everything they say themselves. And most importantly, they don't think that shouting strengthens their argument.
But there were too many points at which the other self could invade the self he wanted to preserve, and there were too many forms of invasion: certain words, sounds, lights, actions his hands or feet performed, and if he did nothing at all, heard and saw nothing, the shouting of some triumphant inner voice that shocked him and cowed him.