HEREDITY. 



Experimental 

 Stage of 

 Psychology. 



Facts of 



Physiological 



Psychology. 



Nerve Action 



Determines 



Sensation. 



sation, with questions relative to time and space 

 in the limits of experiment, movement, modes of 

 expression and language; the conditions of the 

 will and attention ; the forms of the more complex 

 feelings in their relation to the nervous system." 



Physiological psychology is yet in its experi- 

 mental stage. Despite the fact that it is being 

 taught in all of our colleges and universities, it 

 would be difficult to find tw6 authors or instruct- 

 ors who are fully agreed. Even a casual com- 

 parison of the writings of James, Titchener, Her- 

 bart, Wesley, Mills, Romanes, Morgan, Baldwin, 

 Gross, Kuelpe, Ladd, or Wundt reveals a great 

 diversity of opinion, and leaves the student far 

 from any definite conception of mind. 



Notwithstanding the diverstiy of opinion held 

 by physiological psychologists, they are substan- 

 tially agreed upon certain very important proposi- 

 tions, chief among which are : ( i ) All sensation 

 and conscious mentation are related to and 

 dependent upon nerve action. (2) Sensation, 

 consciousness and the power of mind in any given 

 direction is determined by the functional power 

 of the nerves and brain areas through which they 

 are manifested, and the degree of stimulus. (3) 

 Stimuli passing from the sense organs through 

 the afferent or sensory nerves are transformed in 

 the brain and transmitted over to the efferent, or 

 motor nerves, resulting in action. (4) Repeated 

 sensations, emotions or thoughts tend to establish 

 nerve paths and fixed combinations in the cortical 

 structure of the brain so that a like stimulus will 

 flash over the established paths, discharge through 

 the same efferent nerves and thereby reproduce 



