SOME POINTS IN THE PHILOSOPHY OP 

 PHYSICS: THVIE, EVOLUTION, AND CREATION^ 



By E. A. Milne, F.R.S. 



TYhen I agreed to this lecture I stipulated that I might be allowed 

 to interpret the subject announced so as to let my treatment relate 

 less to the subject in general than to some particular aspects which 

 happen to have been interesting me lately. Professor Whitehead, 

 Sir Arthur Eddington, and Sir James Jeans have given to the world 

 brilliant accounts of the present position of physics in relation to 

 mathematics and philosophy. Wliat I have to say bears to their 

 writings the humble relation of an example to a piece of book work, 

 or of an application of a theorem to the theorem itself. 



The particular subject to which I invite your attention is that 

 of time and space, more particularly time, in relation to relativity 

 and thermodynamics, and the time and space of the whole world. 

 The present position in physics of time seems to me to offer difficul- 

 ties, and it may interest you if I attempt to discuss them for a 

 " short space of time ", whatever that may mean ! 



Strictly speaking, physics has no philosophy. It has method. At 

 any rate physicists, both theoretical and experimental, are rarely 

 philosophers when they are making investigations, but they are 

 acutely conscious of method. Philosophy concerns itself with the 

 justification of these methods, and the ultimate meaning in reality 

 of the results obtained by the methods. Now the methods of theo- 

 retical })hysics seem to be reducible to two species, the method of 

 starting with concepts and the method of starting with things 

 observed. To start with a concept requires two people who agree 

 that they understand what the concept means without giving it an 

 exact definition. They agree that the concept is an entity which, 

 for each of them, stands in the same relation to the things and 

 propositions which are to follow. In some presentations of thermo- 

 dynamics, energy is introduced as a concept; in Sir James Jeans' 

 recent book, The New Background of Science, space and, possibly, 

 even electrons and protons are regarded as mental concepts, though 

 with respect to the latter most physicists would disagree with him. 



1 An address deliverod to the British Institute of riiilosophy on Oct. 17, 1933. Re- 

 printed by permission from Philosophy, January 1934. 



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