70 SOCIAL HEREDITY AND SOCIAL EVOLUTION 



measure explain each other. The rapidity of the 

 evolution of the human mind is partly explained by 

 the aid it received from its new tool language. With- 

 out language animals cannot hand on their expe- 

 riences, and their intelligence could develop no faster 

 than race experience could be incorporated into the 

 organic structure by inheritance. This process, if 

 acquired characters are not inherited, is very slow. 

 Experience is not transmitted by organic inherit- 

 ance, and without language animals could not teach 

 each other nor benefit by each other's experience. 

 But just as soon as a race developed the power of 

 speech the whole problem was changed. Then com- 

 munication between individuals made it possible for 

 the knowledge of the one to be imparted to another. 

 From this time the development would be immensely 

 accelerated. It would be like the avalanche, small at 

 the beginning, but increasing more and more rapidly 

 with each increment. Mind and language would react 

 on each other, and the advance of the one would make 

 possible a new step in the other. Language devel- 

 oped mind and mind created new needs for language. 

 Now, no one will perhaps question this statement, 

 for it is practically self-evident and is a matter of 

 history. But it is hardly a sufficient answer to our 

 question why man alone developed the power of lan- 

 guage and the accompanying mental power, for why 

 should not the same history have occurred in other 

 animals? Sometimes an attempt is made to find an 

 answer in the fact that man alone, of the highly 

 intelligent animals, has developed organs which 

 make articulate speech possible. Herein may doubt- 

 less be one of the reasons why speech belongs to man 

 alone, and why man alone has developed the rapidly 



