SECT. 13.] Measurement of Belief. 133 



otherwise. In fact it is only since the time of Kant that 

 this mental analysis has been to any extent appreciated and 

 accepted. And even now the dominant experience school of 

 philosophy would not admit that there are here two really 

 distinct sides to the phenomenon ; they maintain either that 

 the subjective necessity is nothing more than the conse 

 quence by inveterate association of the objective uniformity, 

 or else that this so-called necessity (say in the Law of Con 

 tradiction) is after all merely verbal, merely a different way of 

 saying the same thing over again in other words. Whatever 

 the explanation adopted, the general result is that fallacies, 

 as real acts of thought, are impossible within the domain of 

 pure logic ; error within that province is only possible by a 

 momentary lapse of attention, that is of consciousness. 



13. But though this perfect harmony between sub 

 jective and objective uniformities or laws may exist within 

 the domain of pure logic, it is far from existing within that 

 of probability. The moment we make the quantity of our 

 belief an integral part of the subject to be studied, any such 

 invariable correspondence ceases to exist. In the former 

 case, we could not consciously think erroneously even though 

 we might try to do so ; in the latter, we not only can believe 

 erroneously but constantly do so. Far from the quantity of 

 our belief being so exactly adjusted in conformity with the 

 facts to which it refers that we cannot even in imagination 

 go astray, we find that it frequently exists in excess or defect 

 of that which subsequent judgment will approve. Our in 

 stincts of credence are unquestionably in frequent hostility 

 with experience ; and what do we do then ? We simply 

 modify the instincts into accordance with the things. We 

 are constantly performing this practice, and no cultivated 

 mind would find it possible to do anything else. No man 

 would think of divorcing his belief from the things on which 



