88 MODES OF RESEARCH IN GENETICS 



interested, these multitudinous minor causes do not 

 play any significant part in the differential deter- 

 mination of a particular event at a particular in- 

 stant of time. There is in connection with the 

 causation of most events some one or two, or at 

 most a very few, outstanding cause groups which, 

 for all practical purposes, at a given moment com- 

 pletely determine their occurrence. The total 

 effect of all the vast number of other minor causes 

 concerned in the remote past is so minute, as com- 

 pared with the part played by the really determina- 

 tive ones at the moment, as to be negligible. In 

 other words, all natural cause groups are not small, 

 nor of equal (balanced) values in the final deter- 

 mination of the event to which they relate, pro- 

 vided we confine ourselves to the time limits of 

 finite practical operations. Yet something very 

 much of that sort seems to me to be implicitly 

 involved in any such generalized statistical view 

 of the universe as that which Professor Royce 

 holds up for our admiration as a sort of scientific 

 ideal. 



The fact that all natural causes or cause groups 

 are not equally significant quantitatively is, of 

 course, what makes the experimental method 

 fruitful one might even say possible in sci- 

 ence. The very essence of the experimental 

 method is that the conditions for the happening 

 of an event are so arranged that the influence of 

 one putative causal factor may be tested at a 



