HUMAN FREEDOM 429 



likely," insists the author, "that the principle of the con- 

 servation of energy or the second law of thermo-dynamics 

 would be found faulty than that we should return to a system 

 of strict causality." * Hence for Compton the problem is one 

 of constructing a theory from which it will be possible to 

 deduce both the fact of human freedom and the fact of a 

 non-causal nature. 



The unpredictability of natural events means that in 

 connection with small particles "knowledge of the initial 

 conditions does not enable us to predict what will happen, 

 for with the same initial conditions we cannot consistently 

 produce the same effect." 2 Hence a particle which chooses 

 one path would be physically indistinguishable from a par- 

 ticle which chooses another. The question then arises as to 

 whether there would be any distinction at all between two such 

 particles. The principle of operationalism demands that " only 

 those aspects of the world have reality which are capable of 

 showing themselves in some way to the observer." 3 It ap- 

 parently follows from this that a distinction which is physi- 

 cally undetectable is non-existent, and this seems to be the only 

 conclusion which we can draw as physical scientists. 



But this point of view "is not broad enough to cover all of 

 our experience." 4 Hence we must extend our postulate in 

 such a way as to permit the discerning of differences where 

 there are no physical differences. This is apparently done 

 by assuming that physical events have properties which are 

 not detectable by physical techniques. On the one hand 

 such an assumption allows for the possibility that two 

 physical particles should differ, say, in "goodness" and 

 'badness." 5 Such a distinction would not be open to 

 physical inspection, but it would not be therefore non- 

 existent. On the other hand such an assumption asserts 

 "that the matter in our brains may occur in conditions 

 which though physically indistinguishable nevertheless cor- 

 respond to distinguishable states of consciousness." 6 Hence 



1 Ibid., p. 23. » ibid., p . 40. 6 Ibid., pp. 39-40. 



2 Ibid., p. 39. * Ibid., p. 43. 6 Ibid., p. 44. 



