Blackwood's Edinburgh Magazine, No. CCCXXXVI. October, 1843. Vol. LIV.. Various

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СКАЧАТЬ pursuing the supposed investigation, (into the operation of reasoning,)" says Archbishop Whately, "it will be found that every conclusion is deduced, in reality, from two other propositions, (thence called Premisses;) for though one of these may be and commonly is suppressed, it must nevertheless be understood as admitted, as may easily be made evident by supposing the denial of the suppressed premiss, which will at once invalidate the argument; e.g. if any one, from perceiving that 'the world exhibits marks of design,' infers that 'it must have had an intelligent author,' though he may not be aware in his own mind of the existence of any other premiss, he will readily understand, if it be denied that 'whatever exhibits marks of design must have had an intelligent author,' that the affirmative of that proposition is necessary to the solidity of the argument. An argument thus stated regularly and at full length, is called a syllogism; which, therefore, is evidently not a peculiar kind of argument, but only a peculiar form of expression, in which every argument may be stated."—Whately's Logic, p. 27.

      "It will be found," he continues, "that all valid arguments whatever may be easily reduced to such a form as that of the foregoing syllogisms; and that consequently the principle on which they are constructed is the Universal Principle of reasoning. So elliptical, indeed, is the ordinary mode of expression, even of those who are considered as prolix writers,—i.e. so much is implied and left to be understood in the course of argument, in comparison of what is actually stated, (most men being impatient, even to excess, of any appearance of unnecessary and tedious formality of statement,) that a single sentence will often be found, though perhaps considered as a single argument, to contain, compressed into a short compass, a chain of several distinct arguments. But if each of these be fully developed, and the whole of what the author intended to imply be stated expressly, it will be found that all the steps, even of the longest and most complex train of reasoning, may be reduced into the above form."—P. 32.

      That it is not the office of the syllogism to discover new truths, our logician fully admits, and takes some pains to establish. This is the office of "other operations of mind," not unaccompanied, however, with acts of reasoning. Reasoning, argument, inference, (words which he uses as synonymous,) have not for their object our advancement in knowledge, or the acquisition of new truths.

      "Much has been said," says Archbishop Whately, in another portion of his work, "by some writers, of the superiority of the inductive to the syllogistic methods of seeking truth, as if the two stood opposed to each other; and of the advantage of substituting the Organon of Bacon for that of Aristotle, &c. &c., which indicates a total misconception of the nature of both. There is, however, the more excuse for the confusion of thought which prevails on this subject, because eminent logical writers have treated, or at least have appeared to treat, of induction as a kind of argument distinct from the syllogism; which, if it were, it certainly might be contrasted with the syllogism: or rather the whole syllogistic theory would fall to the ground, since one of the very first principles it establishes, is that all reasoning, on whatever subject, is one and the same process, which may be clearly exhibited in the form of syllogisms.

      "This inaccuracy seems chiefly to have arisen from a vagueness in the use of the word induction; which is sometimes employed to designate the process of investigation and of collecting facts, sometimes the deducing an inference from those facts. The former of these processes (viz. that of observation and experiment) is undoubtedly distinct from that which takes place in the syllogism; but then it is not a process of argumentation: the latter again is an argumentative process; but then it is, like all other arguments, capable of being syllogistically expressed."—P. 263.

      "To prove, then, this point demonstratively, (namely, that it is not by a process of reasoning that new truths are brought to light,) becomes on these data perfectly easy; for since all reasoning (in the sense above defined) may be resolved into syllogisms; and since even the objectors to logic make it a subject of complaint, that in a syllogism the premises do virtually assert the conclusion, it follows at once that no new truth (as above defined) can be elicited by any process of reasoning.

      "It is on this ground, indeed, that the justly celebrated author of the Philosophy of Rhetoric objects to the syllogism altogether, as necessarily involving a petitio principii; an objection which, of course, he would not have been disposed to bring forward, had he perceived that, whether well or ill founded, it lies against all arguments whatever. Had he been aware that the syllogism is no distinct kind of argument otherwise than in form, but is, in fact, any argument whatever stated regularly and at full length, he would have obtained a more correct view of the object of all reasoning; which is merely to expand and unfold the assertions wrapt up, as it were, and implied in those with which we set out, and to bring a person to perceive and acknowledge the full force of that which he has admitted; to contemplate it in various points of view; to admit in one shape what he has already admitted in another, and to give up and disallow whatever is inconsistent with it."—P. 273.

      Now, what the Archbishop here advances appears convincing; his position looks impregnable. The syllogism is not a peculiar mode of reasoning, (how could it be?)—if any thing at all, it must be a general formula for expressing the ordinary act of reasoning—and he shows that the objections made by those who would impugn it, may be levelled with equal justice against all ratiocination whatever. But then this method of defending the syllogism, (to those of us who have stood beside, in the character of modest enquirers, watching the encounter of keen wits,) does but aggravate the difficulty. Is it true, then, that in every act of reasoning, we do but conclude in one form, what, the moment before, we had stated in another? Are we to understand that such is the final result of the debate? If so, this act of reasoning appears very little deserving of that estimation in which it has been generally held. The great prerogative of intelligent beings (as it has been deemed,) grants them this only—to "admit in one shape what they had already admitted in another."

      From the dilemma in which we are here placed, the Archbishop by no means releases, or attempts to release us: he seems (something too much after the manner and disposition generally attributed to masters in logic-fence,) to have rested satisfied with foiling his opponents in their attack upon the exact position he had bound himself to defend. He saves the syllogism; what becomes, in the controversy, of poor human reason itself, is not his especial concern—it is as much their business as his. You do not, more than I, he virtually says to his opponents, intend to resign all reasoning whatever as a mere inanity; I prove, for my part, that all reasoning is capable of being put into a syllogistic form, and that your objection, if valid against the syllogism, is equally valid against all ratiocination. You must therefore either withdraw your objection altogether, or advance it at your peril; the difficulty is of your making, you must solve it as you can. Gentlemen, you must muzzle your own dog.

      In this posture of affairs the author of the present work comes to the rescue. He shall speak in his own words. But we must premise, that although we do not intend to stint him in our quotation—though we wish to give him all the sea-room possible; yet, for a full development of his views, we must refer the reader to his volumes themselves. There are some disquisitions which precede the part we are about to quote from, which, in order to do complete justice to the subject, ought to find a place here, as well as in the author's work—but it is impossible.

      "It is universally allowed, that a syllogism is vicious, if there be any thing more in the conclusion than was assumed in the premisses. But this is, in fact, to say, that nothing ever was, or can be, proved by syllogism, which was not known, or assumed to be known, before. Is ratiocination, then, not a process of inference? And is the syllogism, to which the word reasoning has so often been represented to be exclusively appropriate, not really entitled to be called reasoning at all? This seems an inevitable consequence of the doctrine, admitted by all writers on the subject, that a syllogism can prove no more than is involved in the premisses. Yet the acknowledgment so explicitly made, has not prevented one set of writers from continuing to represent the syllogism as the correct analysis of what the mind actually performs in discovering and proving the larger half of the truths, whether of science or of daily life, which we СКАЧАТЬ