204 Induction. [CHAP. ix. 



ing others which are at present unknown. He observes a 

 multitude of phenomena, physical and mental, contemporary 

 and successive. He enquires what connections are there 

 between them ? what rules can be found, so that some of 

 these things being observed I can infer others from them? 

 We suppose him, let it be observed, deliberately resolving to 

 investigate the things themselves, and not to be turned 

 aside by any prior enquiry as to there being laws under 

 which the mind is compelled to judge of the things. This 

 may arise either from a disbelief in the existence of any 

 independent and necessary mental laws, and a consequent 

 conviction that the mind is perfectly competent to observe 

 and believe anything that experience offers, and should 

 believe nothing else, or simply from a preference for investi 

 gations of the latter kind. In other words, we suppose him 

 to reject Formal Logic, and to apply himself to a study of 

 objective existences. 



It must not for a moment be supposed that we are here 

 doing more than conceiving a fictitious case for the purpose 

 of more vividly setting before the reader the nature of the 

 inductive process, the assumptions it has to make, and the 

 character of the materials to which it is applied. It is not 

 psychologically possible that any one should come to the study 

 of nature with all his mental faculties in full perfection, but 

 void of all materials of knowledge, and free from any bias as 

 to the uniformities which might be found to prevail around 

 him. In practice, of course, the form and the matter the 

 laws of belief or association, and the objects to which they 

 are applied act and react upon one another, and neither 

 can exist in any but a low degree without presupposing the 

 existence of the other. But the supposition is perfectly legi 

 timate for the purpose of calling attention to the require 

 ments of such a system of Logic, and is indeed nothing more 



