258 MFXHANICAL BASIS OF NATURAL SCIEXCE. 



Thus Poincare asks in the face of these facts the pertinent question, 

 " By what right do we apply to the ether the mechanical properties 

 •observed in ordinary matter ? " 



3. In the third place, even if Nature as a whole could be 

 adequately described in mechanical terms, it would not follow 

 that the mechanical view was the fundamental view. 



This point is made by Professor Whetham with regard to 

 electrical phenomena : — 



" When we turn from mechanics to other branches of physics, it is necessary 

 to use certain fundamental conceptions, such as temperature, and quantity 

 of electricity, though it is probable that ultimately these will be connected 

 with the mechanical units. But such a connection would not show that 

 mechanics is necessarily the more fundamental science ; it would be quite as 

 correct, when the connection is established, to express mechanical quan- 

 tities in terms of electricity or temperature."* 



In other words, if A can be expressed in terms of B, B can be 

 expressed in terms of A, and there is no more reason for thinking 

 the latter to be fundamental than the former. 



To think otherwise is natural but not justifiable. If we can 

 make a picture of the way a thing works we think we have 

 explained it, and this is what mechanics does by reducing natural 

 processes to the movements of molecules. But, as we have 

 seen, the picture, or, to use Kelvin's illustration, our working 

 model of nature, does not really explain nature, but stands itself 

 in need of explanation. 



4. The mechanical theory and organic life. 



If the mechanical theory is inadequate to explain or even to 

 ■describe the problems of physics and chemistry, still more is it 

 inadequate to explain or describe the problems of organic life. 

 We have space to mention three points only in this connection, 

 and that in the briefest way possible. 



[A) The problem of organic life itself has been resolved (or has 

 been considered resolvable) into chemical or mechanical processes. 

 Thus fProf, Ray Lankester offers an emphatic denial to a dictum 

 •of Lord Kelvin's to the effect that 



" modern biologists are coming more and more to a firm acceptance of 

 . a vital principle." 



Sir Michael Foster in a British Association address (1899) agrees 

 with Lord Kelvin that some at least of the problems of life are 

 neither mechanical nor chemical. Prof. Burdon Sanderson, who 

 said that " the word ' vital ' as distinctive of physiological pro- 

 cesses might be abandoned altogether," said, nevertheless, in 

 another place : 



" The only satisfactory methods for the investigation of organic life 

 being physical or chemical the organisation itself came to be considered 

 as a complex of such processes and nothing more. In particular the 

 idea of adaptation, which is not a consequence of organism, but its essence 

 came to be lost sight of." 



Thus if it is wrong to use the word " Vitalism " in the old 

 sense of a " Vital Force," a force, that is, which acts mechanically 

 though it has no mechanical origin, yet, at any rate, we have the 



* {op. cit. p. 28). 



I (" Kingdom of Man," pp. 62, 63.) 



