SECT. 37.] Measurement of Belief. 165 



not demonstrably there), our only resource is to introduce 

 such a series, in other words, as has so often been said, to 

 substitute a series of the right kind. 



37. The above, which may be considered tolerably 

 complete as a definition, might equally well have been 

 given in the last chapter. It has been deferred however 

 to the present place, in order to connect with it at once a 

 proposition involving the conceptions introduced in this 

 chapter ; viz. the state of our own minds, in reference to the 

 amount of belief we entertain in contemplating any one 

 of the events whose probability has just been described. 

 Reasons were given against the opinion that our belief ad 

 mitted of any exact apportionment like the numerical one 

 just mentioned. Still, it was shown that a reasonable expla 

 nation could be given of such an expression as, my belief is 

 T ^th of certainty 3 , though it was an explanation which pointed 

 unmistakeably to a series of events, and ceased to be intel 

 ligible, or at any rate justifiable, when it was not viewed in 

 such a relation to a series. In so far, then, as this expla 

 nation is adopted, we may say that our belief is in pro 

 portion to the above fraction. This referred to the purely 

 intellectual part of belief which cannot be conceived to be 

 separable, even in thought, from the things upon which it 

 is exercised. With this intellectual part there are com 

 monly associated various emotions. These we can to a 

 certain extent separate, and, when separated, can measure 

 with that degree of accuracy which is possible in the case of 

 other emotions. They are moreover intelligible in reference 

 to the individual events. They will be found to increase 

 and diminish in accordance, to some extent, with the fraction 

 which represents the scarcity of the event. The emotion of 

 surprise does so with some degree of accuracy. 



The above investigation describes, though in a very brief 



