EVOLUTION AND ENTROPY 323 



This tenuous hold on truth Is all we can expect in exploring 

 nature's details. 



With all of these restrictions, what is the problem to be 

 treated? It is the paradox mentioned by Lalande more than a 

 generation ago and never fully faced, let alone resolved. The 

 gist of the problem is that there are two conflicting laws 

 reigning in our cosmos. One is the law of evolution leading 

 from disorder to order or from uniformity to differentiation. 

 The other is the law of entropy which finds the cosmos as a 

 whole going from order to randomness and from differentiation 

 to uniformity. How can these opposites co-exist? Are we not 

 in a position like that of Parmenides who was led to deny 

 motion because it seemed to involve irreconcilable opposites? 



Yet, in addition to the undoubted evidence for motion, there 

 may also be enough evidence for both evolution and entropy 

 to bid us find a corresponding place for both of them in our 

 cosmology. In Book I of his Physics, Aristotle found a place 

 for the embryonic theory of evolution in Anaxagoras and for 

 the quasi-entropy of Empedocles. For all of the early natural- 

 ists as serious students of nature saw dimly, Aristotle said, and 

 they framed obscurely, some important truths about nature.*'^ 

 But they did not push their analysis to the fundamental prin- 

 ciples in nature '^^ which are two first contraries and their 

 subject. 



This is not Aristotle's positive argument for primary matter 

 and its two first contraries of substantial form and privation, 

 and we are applying a similar dialectic to approximate *'^ what 

 would be reached scientifically on other grounds. Let us go 

 over the dialectic to see how it operates. 



Evolution and entropy, the uphill and down-hill tendencies 

 detected by modern cosmology, are contraries. They are oppo- 

 sites, and all motion, tends, from different points of view, to 



*^ ". . . for all of them identify their elements, and what they call their principles, 

 with the contraries, giving no reason indeed for the theory, but constrained as it 

 were by the truth itself." Phys., I, 5, 188b 28-30. 



"^St. Thomas, In I Phys., lect. 10, n. 172 (ed. Angelo Pirotta) . 



*^ This is one reason why dialectic is called tentativa. In IV Met., lect. 4, n. 574. 



