68 SOCIAL HEREDITY AND SOCIAL EVOLUTION 



and the animals. We may undoubtedly find among 

 animals rudiments of the mental attributes of man, 

 and we certainly may find a long series of links be- 

 tween the mental powers of animals and those of 

 man. But in the one case these powers develop into 

 intelligence, while in the other they do not. If ani- 

 mals do possess the germs of intelligence, why have 

 not they as well as man developed into the higher 

 plane of mentality? Any complete theory of evolu- 

 tion must recognize this question and find an answer. 

 Man is of comparatively recent origin. Compared 

 with other animals, his life on earth has been only 

 a few centuries. During this brief history his mental 

 powers have progressed immensely, until the dif- 

 ference between him and the most intelligent animals 

 has become prodigious. The very facts that have 

 shown the presence of so many rudiments of mental 

 processes in animals make all the more forcible the 

 question of why in man alone they have developed 

 beyond rudiments. If this mental power is of such 

 value to its possessor, and if the germs of intelli- 

 gence are present in other animals, why is it that in 

 man alone they have developed? Unless we can 

 answer this question we must acknowledge that the 

 problem of the evolution of man is not answered. Is 

 there any answer to the question? 



At first this question seems to be similar to thou- 

 sands of others that might be asked in regard to any 

 other valuable character of animals. If an eye is of 

 so much value, why have not the worms developed 

 eyes? If a wing is so useful to enable its posses- 

 sors to escape their enemies, why has not the rabbit 

 developed wings? Such questions might be asked 

 indefinitely, but science recognizes that they are all 



