306 



REASONING. 



this would be an exact parallel to his doctrine about the belief 

 in matter. 



The existence of matter, and other Noumena, as dis- 

 tinguished from the phenomenal world, remains a question 

 of argument, as it was before ; and the very general, but 

 neither necessary nor universal, belief in them, stands as a 

 psychological phenomenon to be explained, either on the 

 hypothesis of its truth, or on some other. The belief is not a 

 conclusive proof of its own truth, unless there are no such 

 things as idola tribus ; but, being a fact, it calls on antagonists 

 to show, from what except the real existence of the thing be- 

 lieved, so general and apparently spontaneous a belief can have 

 originated. And its opponents have never hesitated to accept 

 this challenge.* The amount of their success in meeting it 

 will probably determine the ultimate verdict of philosophers on 

 the question. 



4. Sir William Hamilton holds as I do, that incon- 

 ceivability is no criterion of impossibility. " There is no ground 

 for inferring a certain fact to be impossible, merely from our 

 inability to conceive its possibility." "Things there are which 

 may, nay must, be true, of which the understanding is wholly 

 unable to construe to itself the possibility." f Sir William 

 Hamilton is however a firm believer in the a priori character 

 of many axioms, and of the sciences deduced from them; and 

 is so far from considering those axioms to rest on the evidence 

 of experience, that he declares certain of them to be true even 

 of Noumena of the Unconditioned of which it is one of the 

 principal aims of his philosophy to prove that the nature of our 

 faculties debars us from having any knowledge. The axioms 

 to which he attributes this exceptional emancipation from the 

 limits which confine all our other possibilities of knowledge ; 

 the chinks through which, as he represents, one ray of light 

 finds its way to us from behind the curtain which veils from 



* I have myself accepted the contest, and fought it out on this battle- 

 ground, in the eleventh chapter of An Examination of Sir William Hamilton' 

 Philosophy. 



t Discussions, &c., 2nd ed. p. 624. 



