33 



the name psychological, but in doing so she has been- 

 actuated more by a desire to facilitate the study of the 

 phenomena which the terms respectively represent, than from 

 any intention of erecting a barrier between them ; for who 

 can define where physiology ends and pyschology commences? 

 Like all other groups of natural laws, physiology and 

 psychology are simply terms used to denote the groupings 

 of certain phenomena, which experience has enabled us to 

 perceive are reducible to law ; but to deny the interaction 

 and interdependence of all natural phenomena would be 

 simply absurd, and a violation of that unity which the 

 greatest and most cultured minds have ever observed in 

 Nature. Physiology and psychology I therefore regard as 

 representing simply different aspects of man's individuality ; 

 and, as in the oVie, so also in the other, the facts of which 

 they consist are those with which Science concerns herself in 

 the light of human experience. Beyond phenomena and 

 experience, she can only concern herself with hypothesis ; 

 and this latter mode of inquiry is unavoidable when we seek 

 for knowledge of causes ; for though " science begins with 

 the investigation of laws, it is perfected only in the deter- 

 mination of causes" secondary and immediate from 

 necessity, and involving merely " invariable antecedents." 



The respective phenomena of physiology and psychology 

 may be grouped into two sets viz., the first external and 

 unconscious, the second internal and conscious ; but it 

 must be conceded that there is an intimate correlation 

 between the two, inasmuch as every mental condition 

 implies and necessitates an antecedent physical condition,, 

 as, for example, in the case of pain, as cited by Ribot, 

 where " this sum of states of consciousness is accompanied 

 by certain states of the organism, motion, play of the 



