EVOLUTION OF MAN 219 



evolutionary process to develop the mentality to wonder about himself and 

 his origin, and to acquire some measure of knowledge in the matter. The 

 human mind, then, is the greatest achievement of the evolutionary process. 

 His mind enables man to wonder and, within limits, to know and under- 

 stand. To a considerable and increasing extent, also, man's mind enables 

 him to control his environment instead of being controlled by it as other 

 animals are. Nor should we forget the emotional and aesthetic attributes 

 of mind, attributes which have underlain some of the noblest achievements 

 of our race. 



The Human Brain 



Because of the preeminent position accorded the human mind, and be- 

 cause of the close association between mind and the functioning of the 

 brain, we shall place emphasis on the development of the brain in our 

 discussion of the evolution of man. Brain development affords some clue 

 to mind development. It is noteworthy in this connection that the out- 

 standing achievement of human evolution was the development of the 

 brain. We have seen that birds specialized in developing wings, horses 

 in developing legs for running, elephants in developing tusks and trunk 

 and giant molars. Man specialized in developing brain. Accordingly, the 

 unique features of man's evolution are largely concerned with the evolu- 

 tion of this brain. It will occupy the center of the stage in the following 

 discussion. 



Before proceeding further a word is in order concerning an omission 

 which will be troubling some readers. We have accorded preeminence 

 to the human mind but have said nothing about the human soul. The 

 reason for the omission lies in the fact that the soul is outside the province 

 of science. Science deals with phenomena which can be detected, studied, 

 and measured by use of scientific instruments. The soul is not amenable 

 to this approach. It cannot be seen, or weighed, or analyzed chemically; 

 nor can it be studied — as yet, at least — by the methods of the psychologist. 

 Thus discussion of the soul would be out of place in a book of science. 

 This may not always be true, but for the present we must look to religion 

 and philosophy for knowledge of the soul. 



Pre-Primate Ancestry 



Man is clearly a mammal. Hence the evolutionary history which we 

 have traced for mammals in general is also his evolutionary history. 



