Some people have a strong sense that they're dead. You can't argue them out of the feeling, you can't show them any evidence whatever which will make them feel better. And if it doesn't seem to occur through logical analysis and discourse then how would it happen at all? In essence, you have to recolor people's thoughts to get them to change. So need somehow to raise the likelihood of making the sensations that they have attached to their thoughts loosen one set of ons, or lower the likelihood of like conning them into thinking wrong things.