344 BRAINS OF RATS AND MEN 



Is surely faulty. And by "reactions" he perhaps does 

 not mean exactly what either Professor Warren or I 

 would mean by that word in this context. 



If our knowledge of physiology were more com- 

 plete, doubtless we could write energy equations for 

 this entire sequence of events. But energy equations 

 do not tell all that we want to know about any series 

 of natural processes. There are time factors and other 

 matters of pattern of performance that may be very 

 significant.' 



We know very little actually about the neurologic 

 aspects of symbolic thinking and choice, but we do 

 know that we think and choose and that these acts 

 are causative agents in determining conduct. With us 

 a course of action may be determined impulsively and 

 unwittingly (as in insects), or it may be determined 

 by the same factors which were operative in the in- 

 sects plus intelligent analysis of the present situation 

 and of the possible future consequences of each of 

 several different reactions to the situation. The pre- 

 vision of possible future consequences of action is a 



' This subject has been discussed by Lotka (1925, p. 409): "A quan- 

 tity which does not appear in the working equation describing the laws 

 of action of a physical system may nevertheless play a significant role 



in the world's events 



The equations of dynamics, however perfectly they may picture the course 

 of certain physical events, may fail entirely to reveal or to give expression 

 to an underlying agency that may, in fact, be of fundamental significance. 

 The interference of consciousness in mechanics may be very real, and yet 

 the course of events may appear fully determined by the laws of 

 dynamics." 



