THE SCIENTIFIC MOOD 27 



characteristically scientific. As Prof. J. H. 

 Poynting has admirably put it: "The hypotheses 

 of science are continually changing. Old hypoth- 

 eses break down and new ones take their place. 

 But the classification of known phenomena which 

 a hypothesis has suggested, and the new discov- 

 eries of phenomena to which it has led, remain 

 as positive and permanent additions to natural 

 knowledge when the hypothesis itself has van- 

 ished from thought." 



CLEARNESS OF VISION. A third character- 

 istic of the scientific mood is the endeavour after 

 clearness, the dislike of blurred vision and ob- 

 scurities. The mole has a sort of half -finished 

 lens, which is physically incapable of throwing 

 any clear image on the retina. If there is any 

 image at all, it must be a blurred tangle of lines. 

 In our busy lives, as the nemesis of our specialisms 

 and pre-occupations, we tend to have moles' 

 lenses in regard to particular orders of facts; we 

 see certain things clearly, but others are blurs. 

 The scientific mood is in continual protest against 

 this; it is all for clearness. 



When we work long at a thing and come to 

 know it up and down, in and out, through and 

 through, it becomes in quite a remarkable way 

 translucent. The botanist can see through his 

 tree, see wood and bast, cambium and medullary 

 rays, all in their proper place; he can see the 



