I’ve enjoyed M. Scott Peck’s book: The People of the Lie; so much so, that I’ve lined up The Road Less travelled to read next.
Having said this, I was rather taken aback with this paragraph:
The diagnosis of possession is not an easy one to make. Neither of these two cases had “bulging eyes” or demonstrated any clearly supernatural phenomena before the exorcism proper. Both showed multiple manifestations of routine mental illness such as depression or hysteria or loosening of associations. Authorities who encounter cases often like to ask, ‘Is the patient possessed or is he or is she mentally ill?’ It is not a valid question. As far as I can currently understand these matters, there has to be a significant emotional problem for the possession to occur in the first place. Then the possession itself will both enhance that problem and create new ones. The proper question is: ‘Is the patient just mentally ill or is he or she mentally ill and possessed?’
Unless I’m completely mis-reading this, the author is positing that only the mentally ill can be demon possessed. I don’t think it a stretch too far to say that ‘a significant emotional problem’ would come under the definition of mental illness.
Working from the premise that demon possession is a reality, I would agree it makes intuitive sense malevolent spirits would exploit any natural weaknesses, but to argue that mental illness must preexist for demon possession to be possible, is at best unfounded, and at worst deeply stigmatising.
In fact, I’d say this type of thinking is demonic.