42 The Universe and Life 



the doctrine that the laws of action are unchanged in 

 the complex arrangements of matter which give men- 

 tal phenomena, is not supported by experimental 

 evidence, as I shall try to show ; on the contrary, it is 

 directly opposed to experimental evidence. Pearson 

 long ago in his Grammar of Science^ emphasized that 

 ground does not exist for teaching dogmatically that 

 the laws of motion are the same in all combinations. 

 The situation has been analyzed from a similar point 

 of view by Lovejoy^ and doubtless by others. There 

 is nothing in these speculations of mechanism that 

 must drive us to reject the efficiency of mental states 

 and events as determiners of action. 



Such being the case, we must turn to other ways of 

 answering such questions. The scientific way of de- 

 termining to what condition an event is due is to 

 separate the conditions under which the event occurs 

 and to try each condition separately, so far as pos- 

 sible, until we find the one or ones that are essential 

 for the event to occur. This is what is called analyti- 

 cal experimentation. It is the method of science, so 

 far as the discovery of causes, of determining factors, 

 is concerned. 



Now, the actions of men and other organisms occur 

 under certain conditions, and we wish to discover 

 which of these conditions bring about the actions. A 

 child burns his finger and withdraws it from the 

 flames, or I change my vote after changing my 



1 See Pearson, Orammar of Science (1895), chap, viii, "Laws of 

 Motion." 



2 See A. O. Lovejoy, "The Meaning of Vitalism," Science, 

 XXXIII (April 21, 1911), 612. 



