Blackwoods Edinburgh Magazine | Page 6

so, the difficulty revives in this shape. Ought you not to have known? Were you warranted in asserting the general proposition without having satisfied yourself of the truth of every thing which it fairly includes? And if not, what, then, is the syllogistic art but a contrivance for catching you in a trap, and holding you fast in it?'
"From this difficulty there appears to be but one issue. The proposition, that the Duke of Wellington is mortal, is evidently an inference, it is got at as a conclusion from something else; but do we, in reality, conclude it from the proposition--All men are mortal? I answer, No.
"The error committed is, I conceive, that of overlooking the distinction between the two parts of the process of philosophizing--the inferring part and the registering part; and ascribing to the latter the functions of the former. The mistake is that of referring a man to his own notes for the origin of his knowledge. If a man is asked a question, and is at the moment unable 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 note-book.
"Assuming that the proposition, The Duke of Wellington is mortal, is immediately an inference from the proposition, All men are mortal, whence do we derive our knowledge of that general truth? No supernatural aid being supposed, the answer must be, from observation. Now, all which men can observe 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. Generalization is not a process of mere naming, it is also a process of inference. From instances which we have observed, we feel warranted 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 contrivance 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 expression; and have thus only one proposition, instead of an endless number, to remember or to communicate. The results of many observations 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 generalization, 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 resides. The inference is finished when we have asserted that all men are mortal. What remains to be performed afterwards is merely deciphering our own notes.
"Archbishop Whately has contended, that syllogizing, or reasoning from generals to particulars, is not, agreeably to the vulgar idea, a peculiar mode of reasoning, but the philosophical 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 inconsequence, have concluded at once, from those instances, that the Duke Wellington is mortal. The mortality of John, Thomas, and Company, 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 general proposition. Since the individual cases are all the evidence we can possess; evidence which no logical form into which we choose to throw it can make greater than it is; and since that evidence is either sufficient in itself, or, if insufficient for one purpose, cannot be sufficient for the other; I am unable to see why we should be forbidden to take the shortest cut from these sufficient premisses to the conclusion, and constrained to travel the 'high priori road' by the arbitrary fiat of logicians. I cannot