3o6 A Limit to Evolution 



ties. This distinction, which is really one of the most 

 important in the whole study of mind and of man, is almost 

 always entirely passed over and ignored. Yet it serves to 

 make plain the existence of that limit to evolution which 

 exists between man and the lower animals, and to show the 

 ' how ' and the ' why ' this limit is a limit. 



There is one plain and obvious difference between man 

 and all brutes. Men speak, but animals are dumb.^ 



Some readers, however, may be inclined to reply that 

 there are such beings as dumb men, and that many animals 

 are eloquent with a language of their own. The songs and 

 calls of birds have meanings which are practically understood 

 by their fellows. Dogs will make certain facts known by 

 their voice, as pointers and setters by their gestures will 

 make known other facts; while parrots and jackdaws will 

 learn actually to speak whole sentences ! 



All this is very true, but it is nothing to the point. As 

 to mutes, the fact that some structural defect hinders one 

 individual from speaking no more proves that man is not 

 essentially a speaking animal than does the fact that another 

 individual cannot speak because he is gagged ! Moreover, 

 most mutes possess a truly intellectual language of gestures. 

 As to animals, no reasonable man can deny the expressive- 

 ness of their language, but it is nevertheless fundamentally 

 different in kind from human language. To see this clearly, 

 it is necessary accurately to understand what we do when we 

 speak. Let us suppose a man and a brute to be standing 

 under an oak-tree which begins to fall. The falling tree will 

 produce similar effects upon the senses of both man and 

 brute. Both will instinctively fly from the danger. Both 

 may cry out from alarm, and both, by their cries and 

 gestures, may give rise to similar feehngs of alarm in other 

 men and brutes. Such language, whether vocal or of gesture, 



1 See aiUe, pp. 182-185. 



