DECLINE OF DETEEMINISM EDDINGTOK 145 



that is the probable effect, but adds that somewhere at the base of 

 physics there are other laws which prescribe just what the fire will 

 do to me, luck or no luck. 



To borrow an analogy from genetics, determinism is a dominant 

 character. We can (and indeed must) have secondary indeterminis- 

 tic laws within any scheme of primary deterministic law— laws which 

 tell us what is likely to happen, but are overridden by the dominant 

 laws which tell us what must happen. So determinism watched with 

 equanimity the development of indeterministic law within itself. 

 What matter? Deterministic law remains dominant. It was not 

 foreseen that indeterministic law when fully grown might be able to 

 stand by itself and supplant its dominant parent. There is a game 

 called "Think of a number." After doubling, adding, and other 

 calculations, there comes the direction "Take away the number you 

 first thought of." We have reached that position in physics, and the 

 time has come to take away the determinism we first thought of. 



The growth of secondary law within the deterministic scheme was 

 remarkable, and gradually sections of the subject formerly dealt 

 with by primary law were transferred to it. There came a time 

 when m some of the most progressive branches of physics secondary 

 law was used exclusively. The physicist might continue to profess 

 allegiance to primary law but he ceased to utilize it. Primary law 

 was the gold to be kept stored in vaults; secondary law was the paper 

 to be used for actual transactions. No one minded ; it was taken for 

 granted that the paper was backed by gold. At last came the crisis 

 and physics went off the gold standard. This happened very re- 

 cently and opinions are divided as to what the result will be. Pro- 

 fessor Einstein, I believe, fears disastrous inflation and urges a 

 return to sound currency-if we can discover it. But most theoreti- 

 cal physicists have begun to wonder why the now idle gold should 

 have been credited with such magic properties. At any rate the 

 thing has happened and the immediate result has been a big advance 

 in atomic physics. 



We have seen that indeterministic or secondary law accounts for 

 regularities of experience, so that it can be used for predictino- the 

 future as satisfactorily as primary law. The predictions and 

 regularities refer to average behavior of the vast number of par- 

 ticles concerned in most of our observations. When we deal with 

 fewer particles the indeterminacy begins to be appreciable, and pre- 

 diction becomes more of a gamble; till finally the behavior of a 

 single atom or electron has a very large measure of indeterminacy. 

 Although some courses may be more probable than others, backing 

 an electron to do anything is in general as uncertain as backing a 

 horse. 



