20S The Unity of the Orgamism 



as the starting point, otherwise the experimenter will be com- 

 mitted to the Idea of the act rather than the act itself. 

 And I take it for granted that no truly present-day biologist 

 is willing, even though he may not be able to justify fully his 

 unwillingness, to commit himself to that ancient position. 

 Very well then, the scratch-reflex is going to be expressed in 

 terms of the oxygen, nitrogen, carbon, phosphorus, and so 

 on, which we are sure are "behind" it. Having recognized 

 the necessity of starting with some particular reflex act, and 

 having settled upon the scratch-reflex, true to his recogni- 

 tion of the necessity for particularity he sees he must go 

 still further in the same direction. If his analysis is to be 

 exhaustive and his expression adequate and final, it will 

 have to particularize still further and concern itself with 

 the reflex of some particular animal species, very likely even 

 with some single individual or small group of individuals. 

 A vast mass of evidence makes it almost certain that a 

 dog's scratch-reflex is different from a cat's, and both are 

 different from an ox's, a frog's', and so on. Suppose, then, 

 the dog's reflex settled upon, and defined so fully that it 

 is distinguished from every other reflex whatever. The stu- 

 dent is now ready for his main undertaking, that of ex- 

 pressing the dog's scratch-reflex in terms of the physico- 

 chemical elements to which the reflex is reducible. 



The next step is to examine the chemical elements con- 

 cerned, as these are treated in inorganic chemistry, for the 

 purpose of seeing what their "terms" are; that is, what 

 their attributes or properties are, the special purpose of this 

 examination being to ascertain what terms, i.e., what at- 

 tributes, answer to, or correspond to, and so can be used to 

 express, the dog's scratch-reflex. The outcome of this 

 examination is unequivocal. It finds no terms, no attri- 

 butes whatever, which by themselves suggest even remotely 

 the reflex under consideration. 



But since the examiner has satisfied himself that no other 



