CHAPTER I 

 WHAT WE DO WITH OUR BRAINS 



The scientific study of man is the most difficult of all 

 branches oj knowledge. 



— Oliver Wendell Holmes 



IN the earliest days of which we have record this 

 question seems not to have arisen. In very- 

 ancient times there was current an idea (con- 

 firmed by modern science) that the emotions are 

 intimately related with certain viscera. The ''y^^^^- 

 ing of the bowels" expresses sound physiology. Even 

 today the tender sentiments are localized in the heart, 

 as every anniversary of St. Valentine's Day reminds 

 us, and in Solomon's time this organ was also regarded 

 as the seat of courage and intellect. "For as he think- 

 eth in his heart, so is he." 



These ancient dogmas took no account of the 

 brain, whose part in the vital economy was an un- 

 solved riddle. Though Hippocrates, Plato, and other 

 Greeks approached the truth, so great a naturalist 

 as Aristotle assigned to the brain the incidental func- 

 tion of serving as a sort of refrigerating plant to cool 

 the too-fervid animal spirits. 



History, the venerable old dame, like other elderly 

 people is said to be inclined to repetition, and in 

 quite recent times some opinions about the functions 

 of the brain that are strongly reminiscent of the 



