THE PARALLEL GROWTH OF OPPOSITES 45 



cally exact application for any place or time when taken 

 by itself. Men who are so fortunate as to be born in a 

 period of exceptional happiness, such as the era of the 

 Antonines, or our own, are apt to mistake it for permanent, 



Come fe il merlo per poca bonaccia 1 ; 



but the winter of the middle ages followed the one, and 

 who shall say what is in store for our own children ? 



Finally, our conclusions are limited by the present as eluci 

 dated by the past. The argument from continuity, to be 

 valid for the future, demands a detailed and exhaustive 

 knowledge of all the several factors in the total process, 

 which we do not possess at the present, and have no reason 

 able prospect of ever attaining to. Beyond the present 

 the result is purely negative. All that we are justified in 

 saying of the future is, that nothing in our knowledge of 

 the past is of a nature to confirm either the hopes of the 

 optimist or the fears of the pessimist ; and there are at 

 least no positive grounds for an expectation that in the 

 future, any more than in the past, either term in the alge- 

 donic equation will gain permanently on the other. 



1 Dante, Purg., xiii. 123. 



