236 NATURE AND MAN. 



elements ; —he would have been able in a brief space, not only to 

 satisfy them of the soundness of his basis, but to erect upon that 

 basis a new and substantial addition to their fabric of knowledge, 

 culminating in a lofty "heaven-kissing" tower, of which every 

 stone should be so firmly and variously knitted to every other, as 

 to leave no room for any suspicion of insecurity. And having, by 

 the strictest methods of observation and experiment, verified his 

 statements — step by step — as to all those facts which are capable 

 of direct demonstration, and having become fully assured, in the 

 course of their inquiries, of their visitor's personal good faith, they 

 would have found no difficulty in crediting his accounts of those 

 celestial marvels of rare occurrence, which it would be altogether 

 beyond his power to reproduce. 



I do not know anymore remarkable fact in the Psychology of 

 Belief, than the universality with which even the most wonderful — 

 I might say the most romantic — results of Spectrum Analysis have 

 been accepted as sober truth, not merely by the whole scientific 

 world, but by the general public. And this universality is, I think, 

 to be attributed to these two conditions : — first, that the absolute 

 concurrence of scientific men on this subject gives to their state- 

 ments the value (if I may so express myself) of bank-notes, which 

 any one may convert into the standard gold of personal knowledge, 

 merely by inquiring into the matter for himself ; — and secondly, 

 that these results are additions to our previous knowledge, and do 

 not run counter to any established beliefs. But suppose they had 

 done so, would they have been the less true in themselves, or 

 have possessed any the less claim on universal acceptance ? The 

 old beliefs would clearly have had to give place in this instance, as 

 they have had to do in many previous cases, to the new knowledge. 

 With one more practical application of this method of study- 

 ing the psychology of belief, I must bring this discourse to a 

 conclusion. 



I alluded at its commencement to a great scientific hypothesis, 

 which is now on its trial at the bar of public opinion, and which, 

 if adopted as a principle of construction, will give a new shape to 

 a large part of our fabric of thought ; and I would say a few 

 words of what seems to me the spirit in which that trial should 

 be conducted. There are many of our securest beliefs, which 



