SECT. 17.] Measurement of Belief. 139 



popular estimation we do seem to be able with more or less 

 accuracy to form a graduated scale of intensity of belief. 

 What we have to examine now is whether this be possible, 

 and, if so, what is the explanation of the fact ? 



That it is generally believed that we can form such a 

 scale scarcely admits of doubt. There is a whole vocabulary 

 of common expressions such as, I feel almost sure/ I do not 

 feel quite certain, &amp;lt;I am less confident of this than of that/ 

 and so on. When we make use of any one of these phrases 

 we seldom doubt that we have a distinct meaning to convey 

 by means of it. Nor do we feel much at a loss, under any 

 given circumstances, as to which of these expressions we 

 should employ in preference to the others. If we were asked 

 to arrange in order, according to the intensity of the belief 

 with which we respectively hold them, things broadly marked 

 off from one another, we could do it from our consciousness 

 of belief alone, without a fresh appeal to the evidence upon 

 which the belief depended. Passing over the looser proposi 

 tions which are used in common conversation, let us take but 

 one simple example from amongst those which furnish nume 

 rical data. Do I not feel more certain that some one will die 

 this week in the whole town, than in the particular street in 

 which I live ? and if the town is known to contain a popula 

 tion one hundred times greater than that in the street, would 

 not almost any one be prepared to assert on reflection that 

 he felt a hundred times more sure of the first proposition 

 than of the second? Or to take a non-numerical example, are 

 we not often able to say unhesitatingly which of two propo 

 sitions we believe the most, and to some rough degree how 

 much more we believe one than the other, at a time when all 

 the evidence upon which each rests has faded from the 

 mind, so that each has to be judged, as we may say, solely on 

 its own merits? 



