I don't understand why even an insane person will do what a Voice tells him to do. There must be more to it than a voice, maybe also an irresistable force or compulsion forcing him to do it, that he can't resist? Because just a voice wouldn't be persuasive if it was saying 'pluck your eyes out.' I mean even if we were in the army and a general told us to pluck our eyes out, we wouldn't obey if they told us to do that, so why obey a voice in one's head.