60 The Destiny of Man. 



the kernel of the change that was wrought 

 when natural selection began to confine it- 

 self to the psychical modification of our an- 

 cestors. In a very deep sense all human 

 science is but the increment of the power 

 of the eye, and all human art is the incre- 

 ment of the power of the hand. Vision 

 and manipulation, these, in their count- 

 less indirect and transfigured forms, are 

 the two cooperating factors in all intellect- 

 ual progress. It is not merely that with 

 the telescope we see extinct volcanoes on 

 the moon, or resolve spots of nebulous 

 cloud into clusters of blazing suns ; it is 

 that in every scientific theory we frame by 

 indirect methods visual images of things 

 not present to sense. With our mind's 

 eye we see atmospheric convulsions on the 

 surfaces of distant worlds, watch the giant 

 ichthyosaurs splashing in Jurassic oceans, 

 follow the varied figures of the rhythmic 

 dance of molecules as chemical element? 

 unite and separate, or examine, with th$ 

 aid of long-forgotten vocabularies now 



