PHYSIOLOGICAL PSYCHOLOGY 233 



necessarily in consciousness, and, in so far forth, is not causal at all. 

 For, of nervous states as such we do not know anything, and never can 

 know anything. Accordingly, the other side proffers its claim, which, 

 in the light of this agnosticism, is very far from being modest. This 

 point was admirably taken by Professor Cattell, in his vice-presidential 

 address to the Anthropological Section of the American Association for 

 the Advancement of Science, in 1888 : 



Much is being written just now regarding the relation of consciousness to 

 the brain. The question is: Do perceptions, thoughts, feelings, volitions, stand 

 in causal interaction with the brain, or are they an epiphenomenon, accom- 

 panying changes in the brain but not influencing them? Are our ordinary 

 actions complex reflexes due to physical stimuli and the structure of the nervous 

 system, or are the changes in the brain that precede movements initiated and 

 directed by consciousness? The question is one of facts that should be settled 

 by scientific methods; and the solution will by no means concern psychology 

 alone. The two greatest scientific generalizations of the present century are the 

 conservation of energy and evolution by the survival of the fit. Now, if con- 

 sciousness alters, however slightly, the position of molecules in the brain the 

 fundamental concept of physical science must be abandoned. If consciousness 

 have no concern in the actions of the individual we have one of the most com- 

 plex results of evolution developed apart from the survival of useful variations, 

 and the Darwinian theory has failed. 16 



We conclude then with the startling reflection that psychology is 

 the keeper of a tremendous oracle. And, on the whole, the oracle keeps 

 silence still. 



16 P. 12. 



