CHAPTER XVI 



REFLEX ACTION 



Mental symbols The origin and evolution of mind Sense-impressions 

 Feelings Pleasure and pain The will. 



355. THE study of the comparative rudimentary minds of 

 lower animals and of the developing minds of children sheds 

 a very clear light on some of the problems of heredity, a 

 knowledge of which in turn helps us greatly to understand 

 many of the phenomena of psychology. Mind presents 

 peculiar difficulties and offers particular advantages to the 

 student of heredity. He deals here with an immaterial 

 something, the workings of which in other living beings he 

 is able to infer only through their actions. On the other 

 hand, he knows nothing so well as his own mind, his sensa- 

 tions, emotions, and thoughts. All knowledge of everything 

 else comes to him through the medium of his mind. What- 

 ever else he may doubt, he cannot doubt the existence, the 

 reality of his own feelings and thoughts. 



356. As I sit here I hold in my hand a pen. I am aware 

 of it, and can be aware of it only through my senses. At 

 the moment three senses are giving me information the 

 sense of sight, the sense of touch, and the muscular sense. 1 

 I know that the thing I hold is a pen, and possibly therefore 

 these sensations are awaking in me other very faint 

 unnoticed representations, from which my conception of a 

 pen is drawn and which, when my attention is called to 

 them, I call memories of other pens. At any rate, the pen 

 appears to me a familiar thing. At the present moment, 

 however, I am clearly conscious only of the vivid sensations 

 aroused by this particular pen. For the sake of simplicity, 

 and for the moment, we may disregard all sensations save 

 those now coming to me through sight. Rays of light are 



1 Or more probably the feelings in my joints. (See James, Principles 

 of Psychology, vol. ii., 189 et seq.) 



209 P 



