140 



REASONING. 



doctrine which we then laid down 

 holds equally true in these more in- 

 tricate cases. The successive general 

 propositions are not steps in the 

 reasoning, are not intermediate links 

 in the chain of inference between the 

 particulars observed and those to 

 which we apply the observation. If 

 we had sufficiently capacious memo- 

 ries, and a sufficient power of main- 

 taining order among a huge mass of 

 details, the reasoning could go on with- 

 out any general propositions ; they are 

 mere formulae for inferring particulars 

 from particulars. The principle of 

 general reasoning is (as before ex- 

 plained), that if, from observation of 

 certain known particulars, what was 

 seen to be true of them can be inferred 

 to be true of any others, it may be 

 inferred of all others which are of a 

 certain description. And in order 

 that we may never fail to draw this 

 conclusion in a new case when it can 

 be drawn correctly, and may avoid 

 drawing it when it cannot, we deter- 

 mine once for all what are the dis- 

 tinguishing marks by which such 

 cases may be recognised. The sub- 

 sequent process is merely that of 

 identifying an object, and ascertain- 

 ing it to have those marks ; whether 

 we identify it by the very marks 

 themselves, or by others which we 

 have ascertained (through another and 

 a similar process) to be marks of those 

 marks. The real inference is always 

 from particulars to particulars, from 

 the observed instances to an unob- 

 served one ; but in drawing this in- 

 ference, we conform to a formula 

 which we have adopted for our guid- 

 ance in such operations, and which is 

 a record of the criteria by which we 

 thought we had ascertained that we 

 might distinguish when the inference 

 could, and when it could not, be drawn. 

 The real premises are the individual 

 observations, even though they may 

 have been forgotten, or, being the 

 observations of others and not of our- 

 selves, may, to us, never have been 

 known : but we have before us proof 

 that we or others once thought them 



sufficient for an induction, and we 

 have marks to show whether any new 

 case is one of those to which, if then 

 known, the induction would have been 

 deemed to extend. These marks we 

 either recognise at once, or by the aid 

 of other marks, which by another pre- 

 vious induction we collected to be 

 marks of the first. Even these marks 

 of marks may only be recognised 

 through a third set of marks ; and 

 we may have a train of reasoning, of 

 any length, to bring a new case with- 

 in the scope of an induction grounded 

 on particulars its similarity to which 

 is only ascertained in this indirect 

 manner. 



Thus, in the preceding example, the 

 ultimate inductive inference was, that 

 a certain government was not likely 

 to be overthown ; this inference was 

 drawn according to a formula in which 

 desire of the public good was set down 

 as a mark of not being likely to be 

 overthrown ; a mark of this mark 

 was acting in a particular manner ; 

 and a mark of acting in that manner 

 was being asserted to do so by intelli- 

 gent and disinterested witnesses : this 

 mark the government under discus- 

 sion was recognised by the senses as 

 possessing. Hence that government 

 fell within the last induction, and by 

 it was brought within all the others. 

 The perceived resemblance of the 

 case to one set of observed particular 

 cases brought it into known resem- 

 blance with another set, and that with 

 a third. 



In the more complex branches of 

 knowledge, the deductions seldom 

 consist, as in the examples hitherto 

 exhibited, of a single chain, a a mark 

 of b, b of c, c of d, therefore a a mark 

 of d. They consist (to carry on the 

 same metaphor) of several chains 

 united at the extremitv, as thus : a a 

 mark of d. ft of e, c of f, d ef of n, 

 therefore a b c a mark of n. Suppose, 

 for example, the following combina- 

 tion of circumstances : i st, rays of 

 light impinging on a reflecting sur- 

 face ; 2nd, that surface parabolic ; 

 3rd, those rays parallel to each other 



