THE PROBLEM OF BODY AND MIND 247 



purpose in bodily affairs without it being possible to prove 

 by caloriraetric methods whether its interaction is accom- 

 panied by expenditure of energy or not. 



It need hardly be said that the view of the soul as some- 

 thing extended in space is not the genuine animism, no 

 matter how subtle that ' something ' may be. Mr. Nor- 

 man Pearson (1916) works with a soul which " has no re- 

 semblance to the ponderable matter of our senses . . . 

 is finer even than the imponderable ether of our inference 

 . . . is, in fact, the nearest conceivable approach to 

 spirit." This may be a legitimate hypothesis, for one can- 

 not dogmatically assert that the extended in space is ex- 

 hausted by ordinary physical methods, but it is not pure 

 animism. 



(VII) The Two-Aspect Theory. There remains a view 

 to which biological facts incline us, f the two-aspect theory ', 

 or the ' Identity Hypothesis ', or the ' correlation theory '. 

 We think of the organism as one, as, while it lives, an in- 

 dissoluble psycho-physical being. The mind and the body 

 are both abstractions, very convenient for purposes of dis- 

 course; there is but one reality, the life of the organism, 

 which has a subjective aspect known as psychosis and an 

 objective aspect known as neurosis. The living creature 

 gives an account of itself in two ways. It can know itself 

 as something extended and intricately built up, burning 

 away, moving, throbbing; it can also know itself as the seat 

 of sensations, perceptions, feelings, wishes, thoughts. But 

 there is not one process, thinking, and another process, cere- 

 bral metabolism ; there is a psycho-physical life a reality 

 which we know under two aspects. This view may be as- 

 sociated with the names of Aristotle, Spinoza, Fechner, 'Eb- 

 binghaus, Lloyd Morgan. Cerebral control and mental 



