CHAPTER XIX 

 RATS AND MEN 



But^ Mousie, thou art no thy lane 

 In proving foresight may be vain: 

 The best laid schemes o' mice an men 



Gang aft a-gley^ 

 An leae us naught but grief an pain 



For promised joy. 



Still thou art blest^ compard wi* me! 

 The present only toucheth thee: 

 But, och! I backward cast my ee 



On prospects drear! 

 An' forward, tho I canna see, 



I guess an fear. 



— Robert Burns 



Men at some time are masters of their fates; 

 The fault, dear Brutus, is not in our stars. 

 But in ourselves, that we are underlings. 



— Shakespeare, Julius Caesar 



RATS are not men. The implications of this 

 thesis have furnished the motives of the pre- 

 ^ ceding discussions, and it may be well now 

 at the close to state explicitly some of these implica- 

 tions. Having reduced most of the behavior of rats 

 and other commonly used laboratory animals to com- 

 plexes of innate impulsions as modified by experience 

 and then crystallized into habits, experimental work- 

 ers in this field not unnaturally extend the principles 



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