172 HABIT AND INTELLIGENCE. [cHAP. 



As life cause of organization. High organization is, however, 



theM-tJan- necessary to any high development of life : life constructs 



ism, so the organism to be at once its dwelling and the means of 



consS-ucts its action. Jvist so, language is the result of thought, but 



language. ^ highly developed language is necessary to any high 



development of thought : thought has constructed the 



organism of language in order to use it as an instrument. 



Considering the unlikeness between the subjects of the 



analogy, the analogy itself is wonderfully close between 



the action of life in building up the organism, and the 



action of thought in constructing language : each forms 



an oroanism to be its instrument. 



Variability All habits are gradually variable ; and habits of using 



gua^r particular words are peculiarly so : that is to say, the 



both in words themselves are variable. Words vary both in their 



of words forms and in their meanings. I have argued in the earlier 



aud their Y)?^Tt of this work, that the characters of organic species 



meanings, ^ t • p i 



are variable, with little or no umit as to amount oi change, 

 if only time enough is allowed ; and that all organisms 

 which are morphologically similar, are so by reason of 

 being descended from the same ancestors. If this is true, 

 any difference between parts which are morphologically 

 the same — as, for instance, between the leg of the dog and 

 that of the horse — are due to variation in the course of 

 their descent from their common ancestor ; and such 

 compar- variation is a parallel fact to the variation that takes place 

 f'l^ ^? in the form of words when a word which is fundamentally 

 in the the same is found in different languages. ISTo one doubts, 

 oro-ans'' fo^" instance, that the German word hcide and the English 

 heath are forms of the same word, and that the similarity 

 of the two is due to their common Gothic original. I 

 believe that the modifications, both in the organisms and 

 in the words, are due to modification in the course of 

 descent or derivation ; and that both, consequently, are 

 alike cases of the variation of habit. We usually speak of 

 the descent of living races, and of the derivation of words ; 

 but it is not a violent metaphor to speak of the deriva- 

 tion of the former and of the descent of the latter. 



Words also change their meanings, even within the 



