THE NERVOUS SYSTEM 59 



the organism or of its species with that stimulus. That 

 is, the response to any stimulus depends wholly 

 upon the biologic necessity which led to its evolution. 

 The response to a sharp blow by pain and retreat 

 from the offending point ; the response to an insect- 

 like tickle by the desire to scratch; the response 

 to a soft caressing contact by pleasure and approach, 

 are all specific to the species and the self-protective 

 necessities as a result of which they were evolved in the 

 organism. Similarly, the more obscure and delicate 

 responses of thought and sentiment, of "study," "in- 

 vention," "ambition," "industry," "joy," "sadness," 

 "remorse," are all dependent upon specific stimuli in the 

 environment and are specific to one or another of the 

 biologic purposes of self-preservation, nutrition or pro- 

 creation. That is, according to its phylogeny and its 

 ontogeny, the life of any being may be completely 

 defined in its action patterns. Conversely, given, its 

 action patterns, we should be able to predict the future 

 action of any individual in response to any stimulus. 



Action patterns, as may be seen, are synonymous with 

 "associative memory," with "mind," with "intelli- 

 gence," with "individuality." The single action pat- 

 tern of Venus' fly-trap makes up its limited life 

 and constitutes all it has of "mind." The larger 

 number of action patterns in the more worldly experi- 

 enced frog constitute its life and its correspondingly 

 limited "mind." The multitudinous action patterns 

 of man, representing every phase and degree of animal 

 existence, constitute man's life and man's "mind." 

 Life epitomized thus as the result of a structure played 

 upon by the environment may well be compared, as 



