582 SCIENCE PROGRESS 



of animated being. It is only the slowness of the process that 

 hides the movement from our eyes and suggests the conclusion, 

 so flattering to human vanity, that nature has reached her 

 consummation in us and can no farther go. An immediate 

 result of the promulgation of the evolution theory was thus to 

 give an immense impulse to comparative anatomy ; for it was 

 now recognised that man's bodily frame is not an isolated 

 structure, but that it is closely related to that of many of the 

 other animals, and that the one structure cannot be fully under- 

 stood without the other. Not the least important branch of 

 what we may call the new anatomy was the science of embry- 

 ology, which by a comparison of the human and animal em- 

 bryos was able to demonstrate their close resemblance for a 

 considerable period of their development, and thus to supply a 

 powerful argument in favour of the conclusion, that man and 

 what he calls the lower animals have had a common origin, and 

 that for an incalculable time they probably pursued nearly 

 parallel lines of evolution. In fact, embryology shows that the 

 very process of evolution, which we postulate for the past history 

 of our race, is summarily reproduced in the life-history of every 

 man and woman who is born into the world. 



Turning now from the physical to the mental side of man's 

 nature, we may say that the evolution theory has in like manner 

 opened up a new province of inquiry which has been left unoccu- 

 pied by the older philosophy. Whenever in former days a 

 philosopher set himself to inquire into the principles of the 

 human mind, it was his own particular mind, or at most the 

 minds of his civilised contemporaries, that he proceeded to 

 investigate. When Descartes turned his eyes inwards and re- 

 flected on the operations of his own mind, he believed himself 

 to be probing to the very deepest foundations accessible to 

 human intelligence. It never occurred to him, I imagine, to 

 apply for information to the mind of a Zulu or a Hottentot, 

 still less of a baboon or a chimpanzee. Yet the doctrine of 

 evolution has rendered it highly probable that the mind of the 

 philosopher is indissolubly linked to the minds of these barbarous 

 peoples and strange animals, and that, if we would fully under- 

 stand it, we must not disdain to investigate the intelligence of 

 these our humble relations. 



It is a corollary of the development theory that, simulta- 

 neously with the evolution of man's body out of the bodies of 

 lower animals, his mind has undergone a parallel evolution, 

 gradually improving from perhaps bare sensation to the com- 

 paratively high level of intelligence to which the civilised races 

 have at present attained. And as in the evolution of the bodily 

 form we know that many species of lower orders have survived 

 side by side with the higher to our own day, so in the evolution 



