Mentality and Self-Consciousness 73 



ceptions, it enables us to entertain thoughts and 

 memories, and it empowers us with volition. 

 Although artificial devices can be produced which 

 will respond to external stimuli, retain impres- 

 sions of past experience, and act spontaneously of 

 their own accord, yet their behavior is always 

 completely predetermined by the laws of physics 

 and chemistry, whereas the behavior of living 

 organisms, by virtue of their mentality and self- 

 consciousness, is in a large measure arbitrary 

 and self-determined. 



In the vertebrate animals self-consciousness is 

 coextensive with the central nervous system. 

 Most of the cells of our bodies form parts of us 

 physiologically but not mentally. In order that a 

 cell may form part of us physiologically it is only 

 necessary for it to be definitely coordinated in 

 position and specifically related in function to the 

 other cells of the body, but in order to form part 

 of us mentally it must be coordinated with the 

 cells of the central nervous system on a chemical 

 scale, that it, the channels formed by the polygonal 

 compartments must be in communication, either 

 directly or indirectly, with certain selected chan- 

 nels of the cells of the central nervous system, so 

 that electric impulses traveling through these 

 channels will be transmitted along definite paths 



