16 INTRODUCTION. 



view we are led to take of the problem which logic 

 proposes, must have a tendency favourable to the 

 adoption of some one opinion on these controverted 

 subjects rather than another. Logic, although differing 

 from the higher metaphysics like the other half of a 

 a great whole, (the one being the science of the appre- 

 ciation of evidence, the other having for its main 

 object to determine what are the propositions for the 

 establishment of which evidence is not required,) yet 

 when viewed under another of its aspects, stands in 

 the same relation to this, its sister science, as it does 

 to all the other sciences. For metaphysics, in endea- 

 vouring to solve its own peculiar problem, must 

 employ means, the validity of which falls under the 

 cognizance of logic. It proceeds, no doubt, as far as 

 possible, merely by a closer and more attentive inter- 

 rogation of our consciousness, or more properly 

 speaking, of our memory ; and so far is not amenable 

 to logic. But wherever this method is insufficient to 

 attain the end of its inquiries, it must proceed, like 

 other sciences, by means of evidence. Now, the 

 moment this science begins to draw inferences from 

 evidence, logic becomes the sovereign judge whether 

 its inferences are well-grounded,, or what other 

 inferences would be so. 



This influence, however, of logic over the ques- 

 tions which have divided philosophers in the higher 

 regions of metaphysics, is indirect and remote ; and I 

 can conscientiously affirm, that no one proposition 

 laid down in this work has been adopted for the sake 

 of establishing, or with any reference to its fitness for 

 being employed in establishing, preconceived opinions 

 in any department of knowledge or of inquiry on 

 which the speculative world is still undecided. 



