194 POPULAR SCIENCE MONTHLY 



truth; but I also mean moral truth, of which what we call justice is 

 only one aspect. It may seem that I am misusing words, that I com- 

 bine thus under the same name two things having nothing in common ; 

 that scientific truth, which is demonstrated, can in no way be likened 

 to moral truth, which is felt. And yet I can not separate them, and 

 whosoever loves the one can not help loving the other. To find the 

 one, as well as to find the other, it is necessary to free the soul com- 

 pletely from prejudice and from passion; it is necessary to attain 

 absolute sincerity. These two sorts of truth when discovered give the 

 same joy; each when perceived beams with the same splendor, so that 

 we must see it or close our eyes. Lastly, both attract us and flee from 

 us ; they are never fixed : when we think to have reached them, we find 

 that we have still to advance, and who pursues them is condemned 

 never to know repose. It must be added that those who fear the one 

 will also fear the other; for they are the ones who in everything are 

 concerned above all with consequences. In a word, I liken the two 

 truths, because the same reasons make us love them and because the 

 same reasons make us fear them. 



If we ought not to fear moral truth, still less should we dread 

 scientific truth. In the first place it can not conflict with ethics. 

 Ethics and science have their own domains, which touch but do not 

 interpenetrate. The one shows us to what goal we should aspire, the 

 other, given the goal, teaches us how to attain it. So they can never 

 conflict since they can never meet. There can no more be immoral 

 science than there can be scientific morals. 



But if science is feared, it is above all because it can not give us 

 happiness. Of course it can not. We may even ask whether the beast 

 does not suffer less than man. But can we regret that earthly paradise 

 where man brute-like was really immortal in knowing not that he 

 must die? When we have tasted the apple, no suffering can make us 

 forget its savor. We always come back to it. Could it be otherwise? 

 As well ask if one who has seen and is blind will not long for the 

 light. Man, then, can not be happy through science, but to-day he 

 can much less be happy without it. 



But if truth be the sole aim worth pursuing, may we hope to 

 attain it? It may well be doubted. Headers of my little book 

 ' Science and Hypothesis ' already know what I think about the ques- 

 tion. The truth we are permitted to glimpse is not altogether what 

 most men call by that name. Does this mean that our most legiti- 

 mate, most imperative aspiration is at the same time the most vain? 

 Or can we, despite all, approach truth on some side? This it is which 

 must be investigated. 



In the first place, what instrument have we at our disposal for this 

 conquest ? Is not human intelligence, more specifically the intelligence 



