268 MATERIAL PROGRESS 



mistake ; and there are enthusiasts who expect 

 that considerations of profit will gradually soften 

 men's fighting instincts and reconcile the civilized 

 world to unbroken peace. So high are the hopes 

 that may be built upon a system which is founded 

 upon the narrowest conceptions of self-interest. 



International trade may, accordingly, be re- 

 garded as a flood which is spreading ideas and in- 

 ventions throughout the world, and does not permit 

 them to be monopolized by any particular nation. 

 But we must not forget that from the beginning of 

 human civilization there must have been a current, 

 however slow and intermittent, which maintained 

 some intercommunication between the races of 

 mankind. There is no tribe, however backward, 

 which is unacquainted with the use of fire : the 

 plough and the loom are known almost univer- 

 sally. We can hardly believe that these discoveries 

 and other surprising similarities between the 

 culture of widely separated peoples originated 

 independently at several centres ; and we must, 

 then, suppose that in the course of ages a know- 

 ledge of them filtered gradually around the 

 world. Trade routes have been respected by the 

 most barbarous nations : the blackmail that they 

 levied spared sufficiently high trading profits ; and 

 we find that amber from the Baltic was well- 

 known in Asia centuries before the Trojan war, 

 and that Greek ornaments and vases reached 

 Northern Europe when, to the people of the 

 Mediterranean, it was a land of terrifying fable. 

 Some inventions were so patently useful as to 

 command immediate adoption : the spread of 

 others would be impeded by the force of custom 

 until it was urged by some special pressure. 

 Such may have been exerted by rulers of intelli- 

 gence, or by religious priesthoods. But more 

 potent influences would be those of war and 



