348 INDUCTION. 



or into an individual fact, and whether we proceed 

 by experiment or by ratiocination, every step in the 

 train of inferences is essentially inductive, and the 

 legitimacy of the induction depends in both cases 

 upon the same conditions. 



True it is that in the case of the practical inquirer, 

 who is endeavouring to ascertain facts not for the 

 purposes of science but for those of business, such 

 for instance as the advocate or the judge, the chief 

 difficulty is one in which the principles of induction 

 will afford him no assistance. It lies not in making 

 his inductions but in the selection of them ; in 

 choosing from among all general propositions ascer- 

 tained to be true, those which furnish him with marks 

 by which he may trace whether the given subject 

 possesses or not the predicate in question. In arguing 

 a doubtful question of fact before a jury, the general 

 propositions or principles to which the advocate 

 appeals are mostly, in themselves, sufficiently trite, 

 and assented to as soon as stated : his skill lies in 

 bringing his case under those propositions or prin- 

 ciples ; in calling to mind such of the known or 

 recognised maxims of probability as admit of appli- 

 cation to the case in hand, and selecting from among 

 them those best adapted to his object. Success is here 

 dependent upon natural or acquired sagacity, aided 

 by knowledge of the particular subject, and of subjects 

 allied with it. Invention, though it can be cultivated, 

 cannot be reduced to rule ; there is no science which 

 will enable a man to bethink himself of that which 

 will suit his purpose. 



But when he has thought of something, science 

 can tell him whether that which he has thought of 

 will suit his purpose or not. The inquirer or arguer 

 must be guided by his own knowledge and sagacity 



