ON IMPROVING NATURAL KNOWLEDGE 33 



The improver of natural knowledge absolutely re- 

 fuses to acknowledge authority, as such. For him, 

 scepticism is the highest of duties; blind faith the one 

 unpardonable sin. And it cannot be otherwise, for 

 every great advance in natural knowledge has involved 

 the absolute rejection of authority, the cherishing of 

 the keenest scepticism, the annihilation of the spirit 

 of blind faith; and the most ardent votary of science 

 holds, his firmest convictions, not because the men 

 he most venerates hold them ; not because their verity 

 is testified by portents and wonders; but because his 

 experience teaches him that whenever he chooses to 

 bring these convictions into contact with their primary 

 source, Nature whenever he thinks fit to test them 

 by appealing to experiment and to observation 

 Nature will confirm them. The man of science has 

 learned to believe in justification, not by faith, but by 

 verification. 



Thus, without for a moment pretending to despise 

 the practical results of the improvement of natural 

 knowledge, and its beneficial influence on material 

 civilisation, it must, I think, be admitted that the 

 great ideas, some of which I have indicated, and the 

 ethical spirit which I have endeavoured to sketch, in 

 the few moments which remained at my disposal, con- 

 stitute the real and permanent significance of natural 

 knowledge. 



If these ideas be destined, as I believe they are, to 

 be more and more firmly established as the world grows 

 older; if that spirit be fated, as I believe it is, to ex- 

 tend itself into all departments of human thought, 

 and to become co-extensive with the range of know- 

 ledge; if, as our race approaches its maturity, it dis- 

 covers, as I believe it will, that there is but one kind of 



