13S REASONING. 



§ 2. Suppose tlie syllogism to be, All cows ruminate, tlie animal wliicli 

 is before me is a cow, therefore it ruminates. The minor, if true at all, 

 is obviously so : the only premiss the establishment of which requires 

 any anterior process of iiujuiry, is the major; and provided the induc- 

 tion of which that premiss is the expression was correctly performed, 

 the conclusion resj^ectiiig the animal now present will be instantly 

 drawn ; because as soon as she is compared with the formula, she will 

 be identified as being included in it. But suppose the syllogism to be 

 the following : — All arsenic is poisonous, the substance which is before 

 me is arsenic, therefore it is poisonous. The truth of the minor may not 

 here be obvious at first sight ; it may not be intuitively evident, but may 

 itself be known only by inference. It may be the conclusion of another 

 argument, which, thrown into the syllogistic form, would stand thus: — 

 Whatever forms a compound with hydrogen, which yields a black pre- 

 cipitate with nitrate of silver, is arsenic ; the substance before me con- 

 forms to this condition ; therefore it is arsenic. To establish, therefore, 

 the ultimate conclusion. The substance before me is poisonous, requires 

 a process which, in order to be syllogistically expressed, stands in need 

 of two syllogisms : and we have a Train of Reasoning. 



When, however, we thus add syllogism to syllogism, we are really 

 adding induction to induction. Two separate inductions must have ta- 

 ken place to render this chain of inference possible ; inductions founded, 

 probably, on different sets of individual instances, but which converge in 

 their results, so that the instance which is the subject of inquiry comes 

 within the range of them both. The record of these inductions is con- 

 tained in the majors of the two syllogisms. First, we, or others before 

 us, have examined various objects which yielded under the given cir- 

 cumstances the given precipitate, and found that they possessed the 

 properties connoted by the word arsenic ; they were metallic, volatile, 

 their vapor had a smell of garlic, and so forth. Next, we, or others be- 

 fore us, have examined various specimens which possessed this metallic 

 and volatile character, whose vapor had this smell, &c., and have inva- 

 riably found that they were poisonous. The first observation we judge 

 that we may extend to all substances whatever which yield the precipi- 

 tate : the second, to all metallic and volatile substances resembling 

 those we examined ; and consequently, not to those only which ai'e 

 seen to be such, but to those Avhich are concluded to be such by the 

 prior induction. The substance before us is only seen to come within 

 one of these inductions ; but by means of this one, it is brought within 

 the other. We are still, as before, concluding from particulars to par- 

 ticulars,; but we are now concluding from particulars observed, to other 

 particulars which are not, as in the simple case, seen to resemble them 

 in the material points, but inferred to do so, because resembling them 

 in something else, which we have been led by quite a different set of 

 instances to consider as a mark of the former resemblance. 



This first example of a train of reasoning is still extremely simple, 

 the series consisting of only two syllogisms. The following is some- 

 what more complicated : — No government, which earnestly seeks the 

 good of its subjects, is liable to revolution ; the Prussian government 

 earnestly seeks the good of its subjects, therefore it is not in danger 

 of revolution. The. major premiss in this argument we shall suppose 

 not to be derived from considerations a priori,, hut to be a generaliza- 

 tion from history, which, whether correct or erroneous, must have 



