CH. xxi.] GENESIS OF MAN, INTELLECTUALLY. 301 



through which his correspondences reach limited to the sur 

 face and the substance of the earth. It stretches into the 

 surrounding sphere of infinity.&quot; In all these respects, the 

 extension of the correspondence achieved during the progress 

 of civilization lias been much greater than that achieved 

 during the immediately preceding stages of the evolution of 

 man from an inferior primate. &quot; From early races acquainted 

 only with neighbouring localities, up to modern geographers 

 who specify the latitude and longitude of every place on the 

 globe ; from the ancient builders and metallurgists, knowing 

 but surface deposits, up to the geologists of our day whose 

 data in some cases enable them to describe the material 

 existing at a depth never yet reached by the miner ; from 

 the savage barely able to say in how many days a full moon 

 will return, up to the astronomer who ascertains the period 

 of revolution of a double star ; there has been &quot; an enormous 

 &quot; widening of the surrounding region throughout which the 

 adjustment of inner to outer relations extends.&quot; x It only 

 remains to add that the later and more conspicuous stages of 

 this progress have been determined by that increase in the 

 size and heterogeneity of the social environment which 

 results from the growing interdependence of communities 

 once isolated, and which we have already seen to be the 

 fundamental element of progress in general. For this inte 

 gration of communities has not only directly enlarged the 

 area throughout which adjustments are required to be made, 

 but it has indirectly aided the advances in scientific know 

 ledge requisite for making the adjustments. 



Great, however, as has been the extension of the corre 

 spondence in space which has characterized the progress of 

 the favoured portion of humanity from barbarism to civiliza 

 tion, the extension of the correspondence in time is a much 

 more conspicuous and more distinctly human phenomenon. 

 As we trace this kind of mental evolution through sundry 



1 Speii cer, Principles of Psychology, vol. i. pp. 317, 318. 



