METHODS OF PSYCHOLOGY. 177 



of science is remodeled more quickly and completely than the map of 

 Asia. 



Psychology has never had a well-defined territory. As states of 

 consciousness appear to be less stable and definite than the objects of 

 the material world, so the science of psychology is more shifting in its 

 contents and more uncertain in its methods than any physical science. 

 "We are told indeed in our introductory text-books that psychology is 

 the science of mind and that mind and matter are the most diverse 

 things in the world. It is said further that psychology is a positive 

 science and is thus clearly distinguished from the normative disciplines, 

 such as logic and ethics. Words are also used to set psychology off 

 from sociology, history, philology and the rest. But while all these 

 verbal definitions may satisfy the college sophomore, they must be per- 

 plexing to the candidate for the doctor's degree. 



The distinction between mind and matter is one of the last words 

 of a philosophy which does not yet exist, rather than an axiom of 

 every-day experience on which preliminary definitions may be based. 

 We can not rest satisfied with an empirical psychology in which the 

 distinction is self-evident, an epistemology in which it is explained 

 and a metaphysics in which it disappears. It may be that we follow 

 Descartes rather than Aristotle in our psychology, not so much from 

 the needs of the science itself as from the demands of the church, on 

 the one hand, and of physical science, on the other. The church re- 

 quired souls that might be saved or damned; physics wanted a world 

 independent of individual perception, and as the methods of exact 

 science were extended to the human body it became a part of the 

 physical system. 



To us who have been brought up in the orthodox tradition, the views 

 of some of those who have passed from natural science to metaphysics 

 seem decidedly naive. Thus Mach entitles the concluding section of 

 his Science of Mechanics ' The Eelations of Mechanics to Physiology,' 

 when he is discussing not the question as to whether vital phenomena 

 may be reduced to the laws of matter in motion, but the relations 

 between sensations and the physical stimulus. Pearson tells us in his 

 Grammar of Science that if the cortex of one brain were connected 

 with another by a commissure of nerve substance, there would be 

 ' physical verification of other consciousness.' Ostwald lets energy do 

 hermaphroditic service in the physical and the extra-physical house- 

 holds. 



But it is not certain that such ingenuous commingling of the men- 

 tal and the physical worlds is more repugnant to common sense or 

 natural science than the logical subtleties of the schools, which under- 

 take to define, relate or obliterate them. It is generally assumed that 

 a psychologist must be either an interactionist or a parallelist. Ac- 



