We use concepts like "consciousness"---"mind"---"personality," but we don't really know yet what these things are.' He was shaking his head. 'Not really. Not at all.
William Peter Blatty (1971). “The Exorcist”

We use concepts like "consciousness"---"mind"---"personality," but we don't really know yet what these things are.' He was shaking his head. 'Not really. Not at all.