I30 



REASONING. 



those premises could not prove in 

 the instance of Commodus, what they 

 were inadequate to prove in any col- 

 lection of casts in which his was 

 included. 



The advantage, in judging whether 

 any controverted inference is legiti- 

 mate, of referring to a parallel case, 

 is universally acknowledged. But by 

 ascending to the general proposition, 

 we bring under our view not one 

 parallel case only, but all possible 

 parallel cases at once ; all cases to 

 which the same set of evidentiary 

 considerations are applicable. 



When, therefore, we argue from a 

 number of known cases to another 

 case supposed to be analogous, it is 

 always possible, and generally advan- 

 tageous, to divert our argument into 

 the circuitous channel of an induction 

 from those known cases to a general 

 proposition, and a subsequent appli- 

 cation of that general proposition to 

 the unknown case. This second part 

 of the operation, which, as before ob- 

 Ferved, is essentially a process of in- 

 terpretation, will be resolvable into a 

 syllogism or a series of syllogisms, the 

 majors of which will be general pro- 

 positions embracing whole classes of 

 cases ; every one of which propositions 

 must be true in all its extent, if the 

 argument is maintainable. If, there- 

 fore, any fact fairly coming within 

 the range of one of these general pro- 

 positions, and consequently asserted 

 by it, is known or suspected to be 

 other than the proposition asserts it 

 to be, this mode of stating the argu- 

 ment causes us to know or to suspect 

 that the original observations, which 

 are the real grounds of our conclusion, 

 are not sufficient to support it. And 

 in proportion to the greater chance of 

 our detecting the inconclusiveness of 

 our evidence, will be the increased 

 reliance we are entitled to place in 

 it if no such evidence of defect shall 

 appear. 



The value, therefore, of the syllo- 

 gistic form, and of the rules for using 

 it correctly, does not consist in their 

 being th« form and the rules accord- 



ing to which our reasonings are neces- 

 sarily, or even usually made ; but in 

 their furnishing us with a mode in 

 which those reasonings may always 

 be represented, and which is admir- 

 ably calculated, if they are incon- 

 clusive, to bring their inconclusiveness 

 to light An induction from parti- 

 culars to generals, followed by a syl- 

 logistic process from those generals 

 to other particulars, is a form in which 

 we may always state our reasonings 

 if we please. It is not a form in which 

 we miist reason, but it is a form in 

 which we may reason, and into which 

 it is indispensable to throw our reason- 

 ing when there is any doubt of its 

 validity : though when the case is 

 familiar and little complicated, and 

 there is no suspicion of error, we may, 

 and do, reason at once from the known 

 particular cases to unknown ones.* 



These are the uses of syllogism, as 

 a mode of verifying any given argu- 

 ment. Its ulterior uses, as respects 

 the general course of our intellectual 

 operations, hardly require illustration, 

 being in fact the acknowledged uses 

 of general language. They amount 

 substantially to this, that the induc- 

 tions may be made once for all : a 

 single careful interrogation of experi- 

 ence may suffice, and the result may 

 be registered in the form of a general 

 proposition, which is committed to 

 memory or to writing, and from which 

 afterwards we have only to syllogise. 

 The particulars of our experiments 

 may then be dismissed from the 

 memory, in which it would be impos- 



* The language of ratiocination would, I 

 think, be brought into closer agreement 

 with the real nature of the pi ocess if the 

 general propositions employed m reason- 

 ing, instead of being in the form All men 

 are mortal, or Every man is mortal, were 

 expressed in the form Any man is mortal. 

 This mode of expression, exhibiting as the 

 type of all reasoning from expeiience, "The 

 men A, B, G, (fcc. , are so and so, therefore 

 any man is so and so," would much better 

 manifest the true idea — that inductive 

 reasoning is always, at bottom, inference 

 from particulars to j)articiilar8, and that 

 the wliole function ox general proiwgltions 

 in reasoning is to vouch for th« legitimacy 

 of such inference*. 



