EVOLUTION AND THERMODYNAMICS 



By this he would seem to have meant that a time may some day 

 come when the struggle of mankind against the adverse conditions of 

 life on our planet will have become so severe that further social 

 evolution will become impossible. This was a sensible approach, but 

 it was made in 1885, before statistical mechanics was fully developed, 

 before the second law of thermodynamics had attained its present 

 position of canonical importance, and before its interpreters had 

 challenged the biologists by appropriating the term "organisation." 



One reason why the apparent contradiction between the second 

 law and the process of evolution has not caused more perplexity is 

 that the attention of those few scientific thinkers who try to unify 

 the world-view of science has been largely directed towards the 

 question of the existence of disentropic phases within living matter 

 itself. From the description of the second law already given it must 

 have been quite clear that this generalisation has a statistical basis, 

 and hence that if we had to deal with vessels so small that individual 

 "complexions" could be separated, the statistical law valid for swarms 

 of them might not in all cases hold good. Disentropic, "unusual," 

 fluctuations might then, if amplified (and amplification is a process 

 at which living matter is very efficient), account for such phenomena 

 of high organisational level as "free will." Such a point of view has 

 been ably put by Ralph Lillie^ and discussed by Donnan.^ It would be 

 related to the standpoint of A. H. Compton,^ and of G. N. Lewis,* 

 who describes living organisms as "cheats in the game of entropy." 



"They alone," he wrote, "seem able to breast the great 

 stream of apparently irreversible processes. These processes 

 tear down, living things build up. While the rest o( the world 

 seems to move towards a dead level of uniformity, the living 

 organism is evolving new substances and more and more intricate 

 forms."^ 



Evidently he grasped the whole of the problem, but there is still 

 one insuperable obstacle to the view that living organisms evade the 

 second law of thermodynamics. It is simply that no evidence of any 



1 R. S. Lillie, Science, 1927, 66, 139; Journ. Philos., 1930, 27, 421; 1931, 28, 561* 

 1932,29, 477; Amer. Naturalist, 1934,68, 304; Philos. of Sci., 1934, 1. 296; 1937,4, 202. 



2 F. G. Donnan, Journ. Gen. Physiol., 1927,8, 685. 



3 A. H. Compton, The Freedom of Man (Yale, 1935). 



* G. N. Lewis, The Anatomy of Science (Yale, 1926), ch. vi and viii. 

 ^ The Anatomy of Science^ p. 178. 



