I think he meant that consciousness is currently irreducible. Consider this: 1. Someone figures out in a lab all possible causes of fear via the surveying meth

I think he meant that consciousness is currently irreducible. Consider this: 1. Someone figures out in a lab all possible causes of fear via the surveying method. Fear seems solved. 2. New people appear that claim to experience fear when someone taps their left feet. 3. You have to redo 1. Therefore fear wasn't solved in the first place. Replace "tapping left feet" with something more obscure, or fear with pain, to continue. Underlying problem: you cannot compute the "preimage" of fear.