LANGUAGE 637 



animals enables him to progress along lines which they 

 cannot follow, there is the mental property which forms 

 the topic of this paragraph, in which — so far as experi- 

 ment reveals — man stands apart from all other animals. 

 Language is in its essence nothing more than the adop- 

 tion by mutual consent of arbitrary spoken or written 

 symbols to represent things, actions, and ideas. These 

 symbols are employed as auditory or visual stimuli, 

 registered in the brain as memories, and by the process 

 of association combined with other memories of the par- 

 ticular things, actions, or ideas with which they belong. 

 Language memories thus become part of the machinery 

 of association, namely, of thinking, in the human mind. 

 To illustrate: consider the following sequence of marks, 

 "book". Looked at simply as a spot from which light 

 is reflected into the eye in a certain manner, with the 

 initiation of a certain visual stimulus, this sequence of 

 marks has no meaning whatever. But because the 

 English-speaking races have agreed that these marks 

 when put together in this way are to stand in our minds 

 for the aggregation of printed pages which we know as 

 a book, the symbol achieves great importance. In man 

 the thought processes are carried on in terms of language. 

 We cannot think clearly about anything to which we 

 cannot assign words. It is this fact which makes it so 

 difl&cult for us to evaluate properly the intellectual ac- 

 tivities of animals, which because they have no words 

 with which to think — so far as we can judge — have 

 thoughts that are hazy indeed in comparison with our 

 own. Contrast the education of a young wild animal 

 with that of a child. The former learns chiefly by ex- 

 perience, to some extent by observation. But only things 

 which happen to itself or within its range of observation 

 can possibly contribute to the formation of those asso- 

 ciated memories which make up its intellectual equip- 

 ment. The child, on the other hand, although basing 

 much of its education upon experience and observation, 



