218 DOCTRINE OF EVOLUTION 



Written history furnishes a wealth of material for 

 interpreting the mental conditions of ancient peoples, 

 but beside documentary evidence the anthropologist 

 learns to use inscriptions of prehistoric times, the primi- 

 tive graphic representations on tombs and monuments, 

 and even the characteristics of crude implements like 

 axes and arrow-heads. The layman finds it difficult 

 at first to regard such relics as indications of the mental 

 stature of the people who made and possessed them; 

 but a little thought will show that a man who used a 

 rough stone ax in the time of the ancient Celts could 

 not possibly have had a mind which included the con- 

 ception of a finished iron tool or modern mechanism. 

 So in all departments of human culture, the evolution 

 of material objects may be justly employed in inter- 

 preting and estimating the mental abilities of ancient 

 peoples. 



r 



La^iguage is undoubtedly the most important single ] 



intelleclyual possession of mankind, for it constitutes, * 



as it were, the very framework of social organization. i 



Without a ready means of communication the myriad ! 



human units who perform the varied tasks necessary j 



for the economic well-being of a body-politic would I 



be unable to coordinate their manifold activities with i 



success, and the structure of civilized societies at least * 



would collapse. It needs no legend of a Tower of Babel -^ 

 to make this plain. So fundamental is this truth that 



although we may not have recognized it explicitly, we j 

 unconsciously form the belief that speech and language 

 are exclusive properties of the human species, and even 



