136 THE PRINCIPLES OF SCIENCE. 



relation of identity on which all more complex logical 

 relations must really rest. 



The Nature of Inference. 



The question, What is Inference ? is involved, even to 

 the present day, in as much uncertainty as that ancient 

 question, What is Truth ? I shall in more than one part 

 of this work endeavour to show that inference never does 

 more than explicate, unfold, or develop the information 

 contained in certain premises or facts. Neither in deduc- 

 tive nor inductive reasoning can we add a tittle to our 

 implicit knowledge, which is like that contained in an 

 unread book or a sealed letter. Sir W. Hamilton has well 

 said, ' Reasoning is the showing out explicitly that a pro- 

 position not granted or supposed, is implicitly contained 

 in something different which is granted or supposed m .' 



Professor Bowen has explained 11 with much clearness 

 that the conclusion of an argument states explicitly what 

 is virtually or implicitly thought. ' The process of reasoning 

 is not so much a mode of evolving a new truth, as it is of 

 establishing or proving an old one, by showing how much 

 was admitted in the concession of the two premises taken 

 together.' It is true that the whole meaning of these 

 statements rests upon that of such words as 'explicit,' 

 'implicit,' 'virtual.' That is implicit which is wrapped up, 

 and we render it explicit when we unfold it. Just as the 

 conception of a circle involves a hundred important geome- 

 trical properties, all following from what we know, if we 

 have acuteness to unfold the results, so every fact and 

 statement involves more meaning than seems at first 

 sight. Reasoning explicates or brings to conscious posses- 

 sion what was before unconscious. It does not create, nor 



m Lectures on Metaphysics, vol. iv. p. 369. 



n Bowen, ' Treatise on Logic/ Cambridge, U. S., 1866; p. 362. 



