THE CHARACTERISTICS OF HUMAN LIFE 63 



enlarging of brain does not produce mental faculties ; 

 but the working of mental faculties leads to enlarge 

 ment of brain. The line of evidence gives way at a 

 point critical for the theory. 



The whole wide circumference of rational experience 

 and effort, now stretches before us, outstretching 

 nerve sensibility, and nerve control centred in the 

 brain, the distinctive characteristic of human life 

 comes fully into view. We have seen how closely 

 allied with all animal life human organism is ; we are 

 now to see how widely severed from all animal life, 

 how completely exalted above it all, is the life which 

 is distinctively human. We have now lying before 

 us phenomena which can by no means be attributed 

 to organism, yet belonging to the ordinary human life. 

 Rational interpretation of sensory experience marks 

 the line of separation here; and from this all dis 

 tinctively human activity opens out. Here we enter 

 upon a field of activity so vast, that its possibilities 

 seem endless. Diversities appearing in this region 

 of activity are completely beyond those variations 

 occurring in animal life, which have supplied data 

 for Darwin s theory. A remarkable difference in 

 scientific classification here becomes apparent. On 

 the physical side, variations lead to new species; on^ 

 the mental side, variations warrant no such distinctive P 

 classifications. Rational life is one, whatever its 

 variations, and this because rational power is the i. 

 basis for the life, however extensive the variations. [I 

 Physiological differences are insufficient to disturb 

 this evidence for the unity of the race. The contrast 

 between physical life and rational, thus becomes very 

 marked. Variations in colour of the skin, in character 



