td2 



feJEASONlNa. 



it is got at as a conclusion from some- 

 thing else ; but do we, in reality, con- 

 clude it from the proposition, All men 

 are mortal ? I answer, No. 



The error committed is, T conceive, 

 that of overlooking the distinction 

 between two parts of the process of 

 philosophising, the inferring part, and 

 the registering part, and ascribing to 

 the latter the functions of the former. 

 The mistake is that of referring a 

 person to his own notes for the origin 

 of his knowledge. If a person is asked 

 a question, and is at the moment un- 

 able to answer it, he may refresh his 

 memory by turning to a memorandum 

 which he carries about with him. But 

 if he were asked, how the fact came 

 to his knowledge, he would scarcely 

 answer, because it was set down in his 

 notebook : unless the book was writ- 

 ten, like the Koran, with a quill from 

 the wing of the angel Gabriel. 



Assuming that the proposition, The 

 Duke of Wellington is mortal, is im- 

 mediately an inference from the pro- 

 position. All men are mortal ; whence 

 do we derive our knowledge of that 

 general truth ? Of course from obser- 

 vation. Now, all which man can ob- 

 serve are individual cases. From 

 these all general truths must be drawn, 

 and into these they may be again 

 resolved ; for a general truth is but 

 an aggregate of particular truths ; a 

 comprehensive expression, by which 

 an indefinite number of individual 

 facts are affirmed or denied at once. 

 But a general proposition is not merely 

 a compendious form for recording and 

 preserving in the memory a number 

 of particular facts, all of which have 

 been observed. Generalisation is not 

 a process of mere naming, it is also a 

 process of inference. From instances 

 which we have observed, we feel war- 

 ranted in concluding, that what we 

 found true in those instances, holds 

 in all similar ones, past, present, and 

 future, however numerous they may 

 be. We then, by that valuable con- 

 trivance of language which enables 

 us to speak of many as if they were 

 one, record all that we have observed, 



together with all that we infer from 

 our observations, in one concise ex- 

 pression ; and have thus only one 

 proposition, instead of an endless 

 number, to remember or to communi- 

 cate. The results of many observa- 

 tions and inferences, and instructions 

 for making innumerable inferences in 

 unforeseen cases, are compressed into 

 one short sentence. 



When, therefore, we conclude from 

 the death of John and Thomas, and 

 every other person we ever heard of 

 in whose case the experiment had 

 been fairly tried, that the Duke of 

 Wellington is mortal like the rest, 

 we may, indeed, pass through the 

 generalisation. All men are mortal, as 

 an intermediate stage ; but it is not 

 in the latter half of the process, the 

 descent from all men to the Duke of 

 Wellington, that the inference re- 

 sides. The inference is finished when 

 we have asserted that all men are 

 mortal. What remains to be per- 

 formed afterwards is merely decipher- 

 ing our own notes. 



Archbishop Whately has contended 

 that syllogising, or reasoning from 

 generals to particulars, is not, agree- 

 ably to the vulgar idea, a peculiar 

 mode of reasoning, but the philo- 

 sophical analysis of the mode in which 

 all men reason, and must do so if they 

 reason at all. With the deference 

 due to so high an authority, I cannot 

 help thinking that the vulgar notion 

 is, in this case, the more correct. If, 

 from our experience of John, Thomas, 

 &c., who once were living, but are 

 now dead, we are entitled to conclude 

 that all human beings are mortal, we 

 might surely without any logical in- 

 consequence have concluded at once 

 from those instances that the Duke 

 of Wellington is mortal. The mor- 

 tality of John, Thomas, and others 

 is, after all, the whole evidence we 

 have for the mortality of the Duke of 

 Wellington. Not one iota is added 

 to the proof by interpolating a gen- 

 eral proposition. Since the indivi- 

 dual cases are all the evidence we 

 ! can possess, evidence which no logical 



