122 PSYCHO-PHYSICAL METHOD 



maintains also intimate relations. Here, again, it not 

 only makes use of the analytic descriptions of mental 

 states effected by introspective psychology, but it has 

 given, perhaps as much as it has received, for its adop- 

 tion of experimental methods has led to the extension 

 of these methods to the investigation of problems that 

 are not strictly psycho-physical, but rather belong to pure 

 psychology ; it has thus raised empirical psychology from 

 the level of a science of simple observation to the plane 

 of experimental science ; and at the same time it tends 

 always to bring a larger part of the domain of pure 

 psychology within its own boundaries, by seeking out 

 the nervous events that are most intimately related with 

 the various psychical states, and exhibiting the correla- 

 tion of events of the two orders. 



Thus it mediates between these two sciences, bringing 

 the data of each to aid in the interpretation of the data 

 of the other ; and so, by bringing about co-operation 

 between them, it is doing away with what has been 

 nothing less than a scandal, the antagonism between 

 the students of the material organism and the students 

 of the psychical processes. 



It seeks the aid also of comparative psychology, which 

 is now being studied with a strictness of method that 

 makes it very different from the mere collection of anec- 

 dotes that for long was all we had in this department. 

 And it is beginning to render intelligible the nature of 

 the instinctive actions of animals, those actions which for 

 so long have seemed to be enveloped in impenetrable 

 mystery, and to enable us to bridge in a vague and 

 tentative way the immense gap between the human and 

 the animal mind. 



Again, it is beginning to bring within its sphere the 

 \vhole problem of animal and especially human evolution, 



