Scientology believes that illness doesn't really exist, that it's all in the mind.
I was talking to a bloke at work who believes that kind of thing, and was telling him that my dad was ill.
"No, he's not ill," he said. "He's only under the impression that he's ill. Just tell him that."
I bumped into him a week later. "How's your dad?"
"He's under the impression that he's dead," I replied.