« ΠροηγούμενηΣυνέχεια »
In this point of view, Lord Monboddo has certainly conducted, with greater skill, his defence of the syllogistic theory; in as much as he has entirely abandoned the important conclusions of Aristotle concerning the natural progress of human knowledge; and has attempted to entrench himself in (what was long considered as one of the most inaccessible fastnesses of the Platonic philosophy) the very ancient theory, which ascribes to general ideas an existence necessary and eternal. Had he, upon this occasion, after the example of Aristotle, confined himself solely to abstract principles, it might not have been an easy task to refute, to the satisfaction of common readers, his metaphysical arguments. Fortunately, however, he has favoured us with some examples and illustrations, which render this undertaking quite unnecessary; and which, in my opinion, have given to the cause which he was anxious to support, one of the most deadly blows which it has ever received. The following panegyric, in particular, on the utility of logic, while it serves to shew that, in admiration of the Aristotelian demonstrations, he did not yield to Dr. Gillies, forms precisely such a comment as I myself could have wished for, on the leading propositions which I have now been attempting to establish.
"In proof of the utility of logic* (says Lord Monboddo) I will "give an example of an argument to prove that man is a substance; "which argument, put into the syllogistic form, is this:
"Every Animal is a Substance;
"Every Man is an Animal;
"Therefore every Man is a Substance."
ing passages (which I am led to select from their connexion with the present argument) strike me as not only widely different, but completely contradictory, in their import.
"According to Aristotle definitions are the foundations of all science, but those foun tains are pure only when they originate in an accurate examination, and patient comparison of the perceptible qualities of individual objects." Vol. I. p. 77.
"Demonstrative truth can apply only to those things which necessarily exist after a certain manner, and whose state is unalterable: and we know those things when we know their causes: Thus we know a mathematical proposition, when we know the causes that make it true; that is, when we know all the intermediate propositions, up to the first principles or axioms, on which it is ultimately built." Ibid. pp. 95, 96.
It is almost superfluous to observe, that while the former of these quotations founds all demonstrative evidence on definitions, the latter founds it upon axioms Nor is this all. The former (as is manifest from the second clause of the sentence) can refer only to contingent truths; in as much as the most accurate examination of the perceptible qualities of individual objects can never lead to the knowledge of things which necessarily exist after a certain manner. The latter as obviously refers (and exclusively refers) to truths which resemble mathematical theorems.
As to Aristotle's assertion, that definitions are the first principles of all demonstrations (ai apxas τav aπedežev oi ipsoμos.) it undoubtedly seems, at first view, to coincide exactly with the doctrine which I was at so much pains to inculcate, in treating of that peculiar evidence which belongs to mathematics. I hope, however, I shall not, on this account, be accused of plagiarism, when it is considered, that the commentary upon these words, quoted above from Dr. Gillies, absolutely excludes mathematics from the number of those sciences to which they are to be applied —On this point, too, Aristotle's own language is decisive. Εξ αναγκαίων αρα συλλογισμος εστιν ή αποδειξις. Analyt. Poster. Lib. i eap. iv.
* Ancient Metaphysics, Vol. V. p. 152.
"There is no man, I believe, who is not convinced of the truth "of the conclusion of this syllogism: But how he is convinced of "this, and for what reason he believes it to be true, no man can "tell, who has not learned, from the logic of Aristotle, to know "what a proposition, and what a syllogism is. There he will learn, "that every proposition affirms or denies something of some other "thing. What is affirmed or denied is called the Predicate; and "that of which it is affirmed or denied, is called the Subject. The "predicate being a more general idea than the subject of which it "is predicated, must contain or include it, if it be an affirmative "proposition; or if it be a negative proposition, it must exclude it. "This is the nature of propositions: And as to syllogism, the use "of it is to prove any proposition that is not self-evident. And "this is done by finding out what is called a middle term; that is, a "term connected with both the predicate and the subject of the "proposition to be proved. Now, the proposition to be proved "here is, that man is a substance; or, in other words, that substance "can be predicated of man: And the middle term, by which this "connexion is discovered, is animal, of which substance is predi"cated; and this is the major proposition of the syllogism, by which "the major term of the proposition to be proved, is predicated of "the middle term. Then animal is predicated of man; and this is "the minor proposition of the syllogism, by which the middle term "is predicated of the lesser term, or subject of the proposition to "be proved. The conclusion, therefore, is, that as substance con"tains animal, and man is contained in animal, or is part of animal, "therefore substance contains man. And the conclusion is neces"sarily deduced from the axiom I have mentioned, as the founda"tion of the truth of the syllogism, That the whole is greater "than any of its parts, and contains them all.' So that the truth of "the syllogism is as evident as when we say, that if A contain B, "and B contain C, then A contains C.
"In this manner Aristotle has demonstrated the truth of the syllo"gism. But a man, who has not studied his logic, can no more tell "why he believes the truth of the syllogism above mentioned, con"cerning man being a substance, than a joiner, or any common me"chanic, who applies a foot or a yard to the length of two bodies, "and finds that both agree exactly to that measure, and are neither "longer nor shorter, can give a reason why he believes the bodies "to be equal, not knowing the axiom of Euclid, That two things, "which are equal to a third thing, are equal to one another.'
"By this discovery Aristotle has answered the question, which "Pontius Pilate, the Roman Governour, asked of our Saviour, What "Truth is? The answer to which appears now to be so obvious, "that I am persuaded Pilate would not have asked it as a ques66 tion, which he no doubt thought very difficult to be answered, if "he had not studied the logic of Aristotle."*
Ancient Metaphysics, Vol. V. pp. 152, 153, 154.
I have quoted this passage at length, because I consider it as an instructive example of the effects likely to be produced on the understanding by scholastic studies, where they
After perusing the above exposition of Aristotle's demonstration, the reader, if the subject be altogether new to him, will be apt to imagine, that the study of logic is an undertaking of much less difficulty than he had been accustomed formerly to apprehend; the whole resolving ultimately into this axiom, "That if A contains B, "and B contains C, then A contains C." In interpreting this axiom, he will probably figure to himself A, B, and C, as bearing some resemblance to three boxes, the sizes of which are so adapted to each other, that B may be literally put into the inside of A, and C into the inside of B. Perhaps it may be reasonably doubted, if there is one logician in a hundred, who ever dreamed of understanding it in any other sense. When considered in this light, it is not surprising that it should instantly command the assent of the merest novice: Nor would he hesitate one moment longer about its truth, if, instead of being limited (in conformity to the three terms of a syllogism) to the three letters, A, B, C, it were to be extended from A to Z; the series of boxes corresponding to the series of letters, being all conceived to be nestled, one within another, like those which we sometimes see exhibited in the hands of a juggler.
If the curiosity of the student, however, should lead him to inquire a little more accurately into Aristotle's meaning, he will soon have the mortification to learn that when one thing is said by the logician, to be in another or to be contained in another, these words are not to be understood in their ordinary and most obvious sense, but in a particular and technical sense, known only to adepts; and about which (we may remark by the way) adepts are not, to this day, unanimously agreed. "To those (says Lord Monboddo) who know "no more of logic nor of ancient philosophy than Mr. Locke did, it "will be necessary to explain in what sense one idea can be said to "contain another, or the idea less general can be said to be a part "of the more general. And, in the first place, it is not in the sense "that one body is said to be a part of another, or the greater body "to contain the lesser; nor is it as one number is said to contain "another; but it is virtually or potentially that the more general "idea contains the less general. In this way the genus con"tains the species; for the genus may be predicated of every "species under it, whether existing or not existing; so that vir"tually it contains all the species under it, which exist or may ex
become a favourite and habitual object of pursuit. The author (whom I knew well, and for whose memory I entertain a sincere respect) was a man of no common mental powers. Besides possessing a rich fund of what is commonly called learning, he was distinguished by natural acuteness; by a more than ordinary share of wit; and, in the discharge of his ju dicial functions, by the singular correctness, gravity, and dignity of his unpremeditated elocution; and yet, so completely had his faculties been subdued by the vain abstractions and verbal distinctions of the schools, that he had brought himself seriously to regard such discussions as that which I have here transcribed from his works, not only as containing much excellent sense, but as the quintessence of sound philosophy. As for the mathematical and physical discoveries of the Newtonians, he held them in comparative contempt, and was probably prevented, by this circumstance, from ever proceeding farther than the first elements of these sciences. Indeed, his ignorance of both was wonderful, considering the very liberal education which he had received, not only in his own country, but at a foreign university.
And not only does the more general contain the less general, "but (what at first sight may appear surprising) the less general ❝contains the more general, not virtually or potentially but actually. "Thus, the genus animal contains virtually man, and every other "species of animal either existing or that may exist: But the genus "animal is contained in man, and in other animals actually; for man "cannot exist without being in actuality and not potentially only, an "animal."*
If we have recourse to Dr. Gillies for a little more light upon this question, we shall meet with a similar disappointment. According to him, the meaning of the phrases in question is to be sought for in the following definition of Aristotle: "To say that one thing is "contained in another, is the same as saying, that the second can "be predicated of the first in the full extent of its signification; and "one term is predicated of another in the full extent of its significa❝tion, when there is no particular denoted by the subject, to which "the predicate does not apply." In order, therefore, to make sure of Aristotle's idea, we must substitute the definition instead of the thing defined; that is, instead of saying that one thing is contained in another, we must say, that "the second can be predicated of the "first in the full extent of its signification." In this last clause, I give Aristotle all the advantage of Dr. Gillies's very paraphrastical version; and yet, such is the effect of the comment, that it at once converts our axiom into a riddle. I do not say that, when thus interpreted, it is altogether unintelligible; but only that it no longer possesses the same sort of evidence which we ascribe to it, while we supposed that one thing was said by the logician to be contained, in another, in the same sense in which a smaller box is contained in a greater.‡
Ancient Metaphysics, Vol. IV. p. 73.
For the distinction betwixt containing potentially and actually, Lord Monboddo acknow. ledges himself indebted to a Greek author then living, Eugenius Diaconus. (Anc. Mel. Vol. IV. p. 73.) Of this author we are elsewhere told, that he was a Professor in the Patriarch's University at Constantinople; and that he published, in pure Attic Greek, a system of logic, at Leipsic, in the year 1766. (Origin and Progress of Language, Vol. I. p. 45, 2d edit.) It is an extraordinary circumstance, that a discovery, on which, in Lord Monboddo's opinion the whole truth of the syllogism depends, should have been of so very recent a date.
+ Gillies's Aristotle, Vol. I. p. 73. "This remark (says Dr. Gillies) which is the foun dation of all Aristotle's logic, has been sadly mistaken by many. Among others, Dr Reid accuses Aristotle of using as synonymous phrases, the being in a subject, and the being truly predicated of a subject; whereas the truth is, that, according to Aristotle, the meaning of the oue phrase is directly the reverse of the meaning of the other." Ibid.
While I readily admit the justness of this criticism on Dr. Reid, I must take the liberty of adding, that I consider Reid's errour as a mere oversight, or slip of the pen. That he might have accused Aristotle of confounding two things which, although different in fact, had yet a certain degree of resemblance or affinity, is by no means impossible. but it is scarcely conceivable, that he could be so careless as to accuse him of confounding two things which he invariably states in direct opposition to each other. I have not a doubt, therefore, that Reid's idea was, that Aristotle used, as synonymous phrases, the being in a thing, and the being a subject of which that thing can be truly predicated; more especially, as either statement would equally well have answered his purpose.
It is worthy of observation, that Condillae has availed himself of the same metaphorical and equivocal word which the foregoing comments profess to explain, in support
To both comments the same observation may be applied; that, the moment a person reads them, he must feel himself disposed to retract his assent to the axiom which they are brought to elucidate; in as much as they must convince him, that what appeared to be, according to the common signification of words, little better than a truism, becomes, when translated into the jargon of the schools, an incomprehensible, if not, at bottom, an unmeaning ænigma.
I have been induced to enlarge, with more minuteness than I could have wished, on this fundamental article of logic, that I might not be accused of repeating those common-place generalities which have, of late, been so much complained of by Aristotle's champions. I must not, however, enter any farther into the details of the system; and shall therefore proceed, in the next section, to offer a few remarks of a more practical nature, on the object and on the value of the syllogistic art.
General Reflections on the Aim of the Aristotelian Logic, and on the intellectual Habits which the study of it has a tendency to form.-That the improvement of the power of reasoning ought to be regarded as only a secondary Object in the culture of the Un derstanding.
THE remarks which were long ago made by Lord Bacon on the inutility of the syllogism as an organ of scientific discovery, together acon with the acute strictures in Mr. Locke's Essay on this form of reaLocke have soning, are so decisive in point of argument, and, at the same time, so familiarly known to all who turn their attention to philosophical shown in fu inquiries, as to render it perfectly unnecessary for me, on the pres ent occasion, to add any thing in support of them. I shall, therefore, in the sequel, confine myself to a few very general and miscellaneous reflections on one or two points overlooked by these eminent writers; but to which it is of essential importance to attend, in order to estimate justly the value of the Aristotelian logic, considered as a branch of education.*
tility of 7 syllogistiem
It is an observation which has been often repeated since Bacon's time, and which, it is astonishing, was so long in forcing itself on
of the theory which represents every process of sound reasoning as a series of identical propositions. "L'Analyse est la même dans toutes les sciences, parce que dans toutes elle conduit du connu à l'inconnu par le raisonnement, c'est-à dire, par une suite de jugemens qui sont renfermés les uns dans les autres." La Logique.
*To some of my readers it may not be superfluous to recommend, as a valuable cup. plement to the discussions of Locke and B icon concerning the syllogistic art, what has been since written on the same subject, in farther prosecution of their views, by Dr. Reid in his Analysis of Aristotle's Logic, and by Dr. Campbell in his Philosophy of Rhetoric.
[Analysis is the same in all the sciences, because in all, it leads from known to unknown by the reasoning process, that is to say by a succession of judgments which are included the one within the other.]