Chauncey Wright. 91 



cent controversies on the subject. On the other 

 hand, it seems clear to me that the two views are 

 simply two complementary or obverse aspects of 

 the same fundamental truth. 



At first sight it may seem very bold to assert 

 that in every act of our mental lives we make 

 such a grand assumption as that of the constancy 

 of Nature ; but it is very certain that, in some 

 form or other, we do keep making this assump- 

 tion. Every time that the grocer weighs a pound 

 of sugar and exchanges it for a piece of silver, the 

 practical validity of the transaction rests upon 

 the assumption that the same lump of iron will 

 not counterbalance one quantity of sugar to-day 

 and a different quantity to-morrow ; and a similar 

 assumption of constancy in weight and exchange- 

 ability is made regarding the silver. The inde- 

 structibility of matter and the continuity or per- 

 sistence of force are taken for granted, though 

 neither the grocer nor his customer may have re- 

 ceived enough mental training to understand these 

 axioms when stated in abstract form. Nay, more, 

 though they may be superstitious' men, believing 

 in a world full of sprites and goblins; though 

 they may be so ignorant as to suppose that, when 

 wood is burned and water dried up, some portions 

 of matter are annihilated, yet in each of these 



