92 Chauncey Wright. [vi. 



the belief may be said to be a net result of all our 

 experience. 



But this is by no means an adequate account of 

 the matter. The case has another aspect, to which 

 neither Mr. Mill nor Mr. Wright has done justice. 

 How can the constancy of Nature be said to be 

 proved by experience, when we begin by assuming it 

 in each of the single acts of experience which, taken 

 together, are said to prove it ? Does not this look 

 like reasoning in a circle } We are told that the con- 

 stancy of nature is proved for us by an unbroken 

 series of experiences, beginning with our birth and 

 ending with our death ; and yet not one of this series 

 of experiences can have any validity, or indeed any 

 existence, unless the constancy of Nature be tacitly 

 assumed to begin with. It is the balance, we are 

 told, which assures us that no particle of matter is 

 ever lost ; but in weighing things in a balance we 

 must take it for granted that the earth's gravitative 

 force is uniform, — is not one thing to-day and another 

 to-morrow ; nay, we must also assume that the pre- 

 sent testimony of our senses will continue to be 

 consistent in principle with their past testimony. 

 Whatever system of forces we estimate or measure 

 in support of our implicit belief in the constancy of 

 Nature, we must sooner or later appeal to some 



