34 SELECTED ESS A YS FROM LA Y SERMONS 



which directly give the lie to all these convictions, and 

 assume the exact reverse of each to be true. 



The improver of natural knowledge absolutely refuses 

 to acknowledge authority, as such. For him, scepticism is 

 the highest of duties; blind faith the one unpardonable sin. 

 And If 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 justi- 

 fication, 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 endeav- 

 oured to sketch, in the few moments which remained at my 

 disposal, constitute 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 extend itself into all 

 departments of human thought, and to become co-extensive 

 with the range of knowledge; if, as our race approaches its 

 maturity, it discovers, as I believe it will, that there is but 

 one kind of knowledge and but one method of acquiring 



