A HISTORY OF SCIENCE 



of the empire. And if we reflect that this circum- 

 ference of the Greek world was in the nature of the case 

 the widely circling region in which the Greek came in 

 contact with other nations, we shall see at once that 

 there could be no more striking illustration in all 

 history than that furnished us here of the value of 

 racial .mingling as a stimulus to intellectual progress. 

 But there is one other feature of the matter that 

 must not be overlooked. Racial mingling gives 

 vitality, but to produce the best effect the mingling 

 must be that of races all of which are at a relatively 

 high plane of civilization. In Asia Minor the Greek 

 mingled with the Semite, who had the heritage of 

 centuries of culture ; and in Italy with the Umbrians, 

 Oscans, and Etruscans, who, little as we know of their 

 antecedents, have left us monuments to testify to their 

 high development. The chief reason why the racial 

 mingling of a later day did not avail at once to give new 

 life to Roman thought was that the races which swept 

 down from the north were barbarians. It was no more 

 possible that they should spring to the heights of 

 classical culture than it would, for example, be possible 

 in two or three generations to produce a racer from 

 a stock of draught horses. Evolution does not proceed 

 by such vaults as this would imply. Celt, Goth, 

 Hun, and Slav must undergo progressive development 

 for many generations before the population of north- 

 ern Europe can catch step with the classical Greek and 

 prepare to march forward. That, perhaps, is one 

 reason why we come to a period of stasis or retro- 

 gression when the time of classical activity is over. 

 But, at best, it is only one reason of several. 



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