338 BRAINS OF RATS AND MEN 



this is a fact, a datum of experience, the neglect of 

 which leaves the causal sequence incomplete. 



Let us suppose that I am debating whether to 

 spend the ten dollars that I have just received as a 

 birthday present upon a dinner with my wife at a 

 fashionable restaurant or upon a book that we have 

 long wanted to read together. I set over against a gay 

 evening amid the bright lights the prospect of many 

 quiet evenings at home with a favorite author and I 

 cannot make the decision until I recall that I am at 

 present convalescent from an illness. The prospect of 

 a gastric upset following injudicious eating decides 

 the matter and 1 determine to buy the book. 



Every step in the process of making this decision 

 and forming this purpose is causally determined, and 

 the choice actually adopted is the mechanistic expres- 

 sion of the working of my internal organization at the 

 moment of its exercise. The factors which have op- 

 erated in the fabrication of this inner nature whose ex- 

 pression is the purpose are various in the extreme — 

 hereditary disposition, habit, countless memories, 

 etc., all facing backward, and in addition to these the 

 rational analysis and evaluation of the probable 

 future consequences of each of the two lines of con- 

 duct under consideration. This mental act, whose 

 neurologic mechanism I can picture in only the 

 vaguest outlines, is unquestionably the dominant 

 factor in the causal complex. Why not recognize it in 

 its own right for what it is and put it in its proper 



