CONCLUSION 353 



ceeds. These revolutions of thought as to the final 

 picture do not cause the scientist to lose faith in his 

 handiwork, for he is aware that the completed portion 

 is growing steadily. Those who look over his shoulder 

 and use the present partially developed picture for 

 purposes outside science, do so at their own risk. 



The lack of finality of scientific theories would be a 

 very serious limitation of our argument, if we had staked 

 much on their permanence. The religious reader may 

 well be content that I have not offered him a God 

 revealed by the quantum theory, and therefore liable 

 to be swept away in the next scientific revolution. It is 

 not so much the particular form that scientific theories 

 have now taken — the conclusions which we believe we 

 have proved — as the movement of thought behind them 

 that concerns the philosopher. Our eyes once opened, 

 we may pass on to a yet newer outlook on the world, 

 but we can never go back to the old outlook. 



If the scheme of philosophy which we now rear on 

 the scientific advances of Einstein, Bohr, Rutherford 

 and others is doomed to fall in the next thirty years, it 

 is not to be laid to their charge that we have gone astray. 

 Like the systems of Euclid, of Ptolemy, of Newton, 

 which have served their turn, so the systems of Einstein 

 and Heisenberg may give way to some fuller realisation 

 of the world. But in each revolution of scientific thought 

 new words are set to the old music, and that which has 

 gone before is not destroyed T^ut refocussed. Amid all 

 our faulty attempts at expression the kernel of scientific 

 truth steadily grows; and of this truth it may be said — 

 The more it changes, the more it remains the same 

 thing. 



