90 THE NATURE OF LIFE 



and control the activities of the organ- 

 ism. 



When we have done this successfully 

 we shall doubtless be able to say whether 

 the simplest cells possess any features 

 which cannot be explained upon a phys- 

 icochemical basis. 



In the meantime we are free to form 

 such working hypotheses as we choose. 

 It should be said, however, that the 

 mechanistic point of view has been vastly 

 more productive in research than the vi- 

 talistic. If we regard the organism as a 

 machine we have a powerful incentive 

 to endeavor to control it as we control 

 other machines. 



The imitation of various life processes 

 has already been discussed. It has also 

 been stated that in many cases the behavior 

 of the organism is predictable, as in the 

 reaction of the root to gravitation or in 

 the changes of the electrical resistance 

 of the organism under various conditions. 

 If we deal with large numbers of individ- 

 uals (as the chemist and physicist deal 



