CHAPTER IV 



PSYCHOLOGICAL SCIENCE 



WE have now reached the last of our divisions of 

 science that which deals with the phenomena of 

 mind, the organ by which we are enabled to appre- 

 hend the world as seen in the physical and biological 

 sciences. 



In the history of human thought, we find that, for 

 a long while, the study of mind followed exclusively 

 the methods of introspection ; but in recent years 

 experiment has been applied to mental phenomena 

 also, and, for our purpose, it will be simpler to ap- 

 proach the subject from the experimental side. 



We may begin by examining our sense-perceptions 

 properties of the human body, varying from in- 

 dividual to individual, giving rise to the sensations 

 our minds experience when our senses are stimulated. 



The sense of touch, by which we distinguish many 

 physical properties, varies greatly when different 

 parts of the body are affected, and for practical use 

 often seems to be concentrated in the finger-tips. The 

 sensitiveness of the nerves of the skin to a light touch 

 may be estimated by exploring the skin with a series 



71 



