ABSTRACT
By a ‘physical’ theory I mean one which involves only agencies and laws of the kind acceptable in principle to physics as currently practised. Specifically, in a ‘physical’ theory in my sense, it is permissible to introduce only agencies located in physical space-time, which interact according to laws of the kind recognized in classical physics and chemistry, and latterly in relativity theory and quantum theory. Applied to the processes of perception (normal and paranormal) and the other functions of a human being, such a theory would be an instance of what Professor Price has called a ‘Materialistic’ or ‘Naturalistic’ theory of human nature (‘Psychical Research and Human Personality’). 1 Price calls any theory ‘Materialistic’ (or ‘Naturalistic’) which maintains ‘that mental processes of every kind are unilaterally dependent upon physico-chemical processes in the brain. … This, or something like this, is the Materialist conception of human personality, technically called Epiphenomenalism.’
