432 INTRODUCTION TO PHILOSOPHY OF SCIENCE 



physical features of events. It may be said, in a sense, to be 

 controlled by a non-physical property of events, since voli- 

 tion is affected by the "goodness" or "badness" of events. 

 Hence volition is causally responsible not to the physical 

 realm, which would destroy freedom, but merely to an 

 anterior mind-state which includes the recognition of moral 

 qualities of events; this, however, as was seen, reduces to 

 self-determinism, which is equivalent to freedom. Accord- 

 ingly, the theory allows for freedom in the sense that it 

 retains the aloofness of volition from the physical processes. 

 But, in the second place, volition is effective over physical 

 processes ; brain particles are under the control of will. How- 

 ever this causal efficacy involves no interruption of the 

 physical course of events, since it occurs only in those situa- 

 tions where physics is unable to ascertain causes. Conse- 

 quently the theory allows for freedom also in the sense that 

 it permits the formulation of the laws which state the func- 

 tional dependence of a physical state upon an earlier voli- 

 tional state. 



PLANCK 



The main difference between Planck and the two writers 

 just considered is that the former argues for human freedom 

 independently of the principle of indeterminacy. As was 

 shown in Chapter XVI, Planck insists that the principle of 

 indeterminacy has no objective implications. To conclude 

 to a complete breakdown of the law of causality seems to him 

 premature. "It is far more natural to avoid the difficulty 

 by another method, a method which has often rendered good 

 service in similar cases and which consists in assuming that 

 it is meaningless, with respect to physics, to ask for the 

 simultaneous values of the coordinates and of the velocities 

 of a material point or for the path of a photon of a given 

 color. Evidently the law of causality cannot be blamed 

 because it is impossible to answer a meaningless question; 

 the blame rests with the assumptions which lead to the 

 asking of the question, i.e., in the present case with the 



