132 REASONING. 



Whately himself, against the doctrine that the syllogistic art is useless 

 for tiie purposes of reasoning. The reasoning lies in the act of gen- 

 eralization, not in intei-preting the record of that act ; but the syllogistic 

 form is an indispensable collateral security for the con-ectness of the 

 generalization itself. 



It has already been seen, that if we have a collection of particulars 

 sufficient for grounding an induction, we need not frame a general 

 proposition ; we may reason at once from those particulars to other 

 particulars. But it is to be remarked withal, that whenever, from a 

 set of particular cases, we can legitimately draw any inference, we 

 may legitimately make our inference a general one. If, from obser- 

 vation and experiment, we can conclude to one new case, so may we 

 to an indefinite number. If that which has held true in our past 

 experience will therefore hold in time to come, it will hold not merely 

 in some individual case, but in all cases of a given description. Every 

 induction, therefore, which suffices to prove one fact, proves an indefi- 

 nite multitude of facts : the expei'ience which justifies a single predic- 

 tion must be such as will suffice to bear out a general theorem. This 

 theorem it is extremely important to ascertain and declare, in its 

 broadest form of generality ; and thus to place before our minds, in 

 its full extent, the whole of what our evidence must prove if it proves 

 anything. ^ ^. 



This throwing of the whole body of possible inferences from a given 

 set of particulars, into one general expression, operates as" a security 

 for their being just inferences in more ways than one. . First, the gen- 

 eral principle presents a larger object to the imagination than any of 

 the singular propositions which it contains. A process of thought which 

 leads to a comprehensive genei'ality, is felt as of ,gi-eater importance 

 than one which terminates in an insulated fact ; and the mind is, even 

 unconsciously, led to bestow greater attention upon the process, and 

 to weigh more carefully the sufficiency of the experience appealed to, 

 for supporting the inference grounded upon it. There is another, and 

 a more important, advantage. In reasoning from a coiu'se of individ- 

 ual observations to some new and unobserved case, which we are but 

 imperfectly acquainted with (or we should not be inquiring into it), 

 and in which, since we are inquiring into it, we probably feel a pecu- 

 liar interest ; there is very little to prevent us from giving way to 

 negligence, or to any bias which may affect our wishes or our imagina- 

 tion, and, under that influience, accepting insufficient evidence as suffi- 

 cient. But if, instead of concluding sfcfaight to the particular case, we 

 place before ourselves an entire class of facts, the whole contents of a 

 general proposition, every tittle of which is legitimately inferable from 

 our premisses, if that one particular conclusion is so ; there is then a 

 considerable likelihood that if the premisses are insufficient, and the 

 general inference, therefore, groundless, it Avill comprise within it some 

 fact or facts the reverse of which we already know to be true ; and 

 we shall thus discover the eiTor in our generalization, by what the 

 schoolmen termed a reductio ad impossihile. 



Thus if, during the reign of Marcus Aurelius, a subject of the Roman 

 empire, under the bias naturally given to the imagination and expec- 

 tations by the lives and characters of the Antonines, had been disposed 

 to conclude that Commodus would be a just ruler: supposing him to 

 Stop there, he might only have been undeceived by sad experience. 



