390 Notices respecting JSew Books. 



I refer to the insistence by Einstein on the impossibility of pre- 

 senting the reality of nature in any purely objective form, that is, 

 in any form which does not take account of the observer and his 

 system of reference. Professor Whitehead will give up absolute 

 space and absolute time, he has no need of material or stuff, the 

 hypothetical ether of the physicists he dismisses with scant respect, 

 but he must have an ether, an ether of events, if, as he holds, the 

 universe consists of events. His scientific instinct will not let 

 him entertain the possibility of a purely subjective reality. To 

 proclaim monads as the real atoms of nature would signify for him 

 the death of physical science. " There is now reigning in philo- 

 sophy and in science an apathetic acquiescence in the conclusion 

 that no coherent account can be given of nature as it is disclosed 

 to us in sense-awareness, without dragging in its relations to 

 mind." To counteract this is the inspiring motive of this book. 

 On one definite point only it joins issue directly with Einstein. 

 Professor Whitehead will not have the bending of space. The 

 gravitational field is not in his view equivalent to the curvature of 

 space in the field. Otherwise he accepts the new formulation 

 and does not challenge the experimental tests by which it is 

 confirmed. 



The first two chapters, entitled "Nature and Thought" and 

 ** The Bifurcation of Nature," are introductory and meant to lead 

 us to the central problem. In the five chapters which follow, — 

 " Time," " The Method of Extensive Abstraction," " Space and 

 Motion," "Congruence," and "Objects," — the author is com- 

 pletely at home, using his own peculiar method, working at what 

 he has happily named the organization of thought. The two last 

 chapters, — " Summary " and " The Ultimate Physical Concepts," — 

 are additions which, Ave are told, formed no part of the original 

 course. They emphasize the conclusion in regard to Einstein's 

 general relativity. 



By the bifurcation of nature, Professor Whitehead means the 

 division of the science of nature into two classes of entities, those 

 disclosed to sense-awareness, and those disclosed to conceptual 

 thought. Materialism he rejects outright. It is so absurdly in- 

 adequate that it is becoming matter of amazement that the 

 scientific opinion of the last century should have taken it, almost 

 universally, as axiomatic. On the other hand, he is vigorous in 

 denouncing metaphysics. A metaphysics of reality is, in his 

 view, completely out of place in the philosophy of science. " It is 

 like throwing a match into the powder magazine. It blows up the 

 whole arena." Philosophy of science is the philosophy of the tiling 

 perceived, while metaphysics confuses everything by embracing 

 within one reality both perceiver and perceived. 



The whole book is valuable therefore in the indication it gives us 

 of the line along which the issue is likely to be joined by physicists 

 who agree in accepting the principle of relativity and yet disagree 

 profoundly in its interpretation. The line of demarcation will be 



