WHAT IS INTELLIGENCE? 187 



ful experience. We must use the exact amount of force 

 in order to accomplish any result with accuracy. In or- 

 dinary walking we learn to put forth exactly the neces- 

 sary amount of energy, neither stamping heavily on the 

 pavement nor putting down our feet so feebly that we 

 would make no progress at all. * * * 



"But it -is very clear that all this precision, co-ordina- 

 tion, and expenditure of the correct degree of muscular 

 energy is only possible in proportion as the muscular and 

 other senses are properly trained. * * * 



"We see, then, that the nervous system puts us into 

 communication with the outer world and its inhabitants 

 which act on us, enables us with speed, accuracy and the 

 correct amount of force to react upon it, and then it makes 

 us aware of our own bodily position to the changing states 

 of the environment. In our nervous system we store 

 memories of what has happened, we register experience 

 for the future, we communicate as we will with our fel- 

 low beings and, maintaining our self-conscious identity, 

 we continue our conscious connection with the past. 

 Nerves and the nervous system not only protect the in- 

 dividual from injury, enabling him to seek food, avoid or 

 overcome enemies ; but they are constantly handing over 

 some activity or other from the conscious to the subcon- 

 scious realm. We educate the nervous system labori- 

 ously to perform certain actions, conscious attention be- 

 ing very much concerned in it. The acquisitions are rele- 

 gated to the unconscious or at least subconscious realm 

 and are at last carried on without the interposition of at- 

 tention at all. There is a very great saving of nerve en- 

 ergy here ; things so done are called habits. Such co- 

 ordinated activities as the maintenance of posture in walk- 

 ing are, in this way, carried on below the conscious level, 

 so that as we walk alone we can be engaged in solving a 



