450 EVOLUTION AND ANIMAL LIFE 



vided into higher and lower nerve centers; centers of con- 

 scious thought and automatic transfer of impulse into motion. 

 This transfer indicates the real nature of all forms of nerve 

 action. All are processes of transfer of sensation into move- 

 ment. The sensorium or brain has no knowledge except such 

 as comes to it from the sense organs through the ingoing or 

 sensory nerves. It has no power to act save by its control of 

 the muscles through the outgoing or motor nerves. The mind 

 has no teacher save the senses; no servants save the muscles. 



The study of the development of mind in animals and men 

 gives no support to the medieval idea that the mind exists as 

 an entity apart from the organ through which it operates. 

 This " Klavier theory" of the mind, that the ego resides in the 

 brain, playing upon the cells as a musician upon the strings of 

 a piano, finds no warrant in fact. So far as the evidence goes, 

 \ve know of no ego, except that which arises from the coordina- 

 tion of the nerve cells. All consciousness is " colonial conscious- 

 ness," the product of cooperation. It stands related to the 

 action of individual cells much as the content of a poem with 

 the words or letters composing it. Its existence is a phenomenon 

 of cooperation. The "I' 1 in man is the expression of the co- 

 working of the processes and impulses of the brain. The brain 

 is made of individual cells, just as England is made of individual 

 men. To say that England wills a certain deed, or owns a 

 certain territory, or thinks a certain thought is no more a figure 

 of speech than to say that "I will," "I own," or "I think." 

 The " England ' is the expression of union of the individual 

 wills and thoughts and ownerships of Englishmen. Similarly, 

 my " ego J; is the aggregate resulting from coordination of the 

 elements that make up my body. 



That what we really know of human personality tells the 

 whole story of it no one should maintain. It is well, however, 

 not to ascribe to it entities and qualities of which we know 

 nothing. 



