CHAPTER X 



ANIMAL INSTINCTS AND TROPISMS 1 



i. The idea that the organism as a whole cannot 

 be explained from a physicochemical viewpoint rests 

 most strongly on the existence of animal instincts 

 and will. Many of the instinctive actions are "pur- 

 poseful," i. e., assisting to preserve the individual and 

 the race. This again suggests "design" and a design- 

 ing "force," which we do not find in the realm of 

 physics. We must remember, however, that there was 

 a time when the same "purposefulness" was believed 

 to exist in the cosmos where everything seemed to 

 turn literally and metaphorically around the earth, 

 the abode of man. In the latter case, the anthropo- 

 or geocentric view came to an end when it was shown 

 that the motions of the planets were regulated by 

 Newton's law and that there was no room left for the 



1 Ideas similar to those expressed in this chapter may be found in the 

 writer's former book Comparative Physiology of the Brain and Compara- 

 tive Psychology, New York, 1900, and in the books by George Bohn, 

 La Naissance de V Intelligence, Paris, 1909, and La nouvelle Psychologie 

 animate, Paris, 191 1. 



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