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which kind to refer any one individual Fallacy. For, since, in any IndetermiArgument, one Premiss is usually suppressed, it frequently happens, character of in the case of a Fallacy, that the hearers are left to the alternative Fallacies. of supplying either a Premiss which is not true, or else, one which does not prove the Conclusion. E.G. If a man expatiates on the distress of the country, and thence argues that the government is tyrannical, we must suppose him to assume either that " every distressed country is under a tyranny," which is a manifest falsehood, or, merely that " every country under a tyranny is distressed,' which, however true, proves nothing, the Middle-term being undistributed. Now, in the former case, the Fallacy would be referred to the head of "extra dictionem;" in the latter to that of "in dictione." Which are we to suppose the speaker meant us to understand? Surely just whichever each of his hearers might happen to prefer: some might assent to the false Premiss; others, allow the unsound Syllogism; to the Sophist himself it is indifferent, as long as they can but be brought to admit the Conclusion. Without pretending, then, to conform to every one's mode of speaking on the subject, or to lay down rules which shall be in themselves (without any call for labour or skill in the person who employs them) readily applicable to, and decisive on, each individual case, I shall propose a division which is at least perfectly clear in its main principle, and coincides, perhaps, as nearly as possible, with the established notions of Logicians on the subject.

§ 2.

Fallacies.

In every Fallacy, the Conclusion either does, or does not follow Logical from the Premises. Where the Conclusion does not follow from the Premises, it is manifest that the fault is in the Reasoning, and in that alone; these, therefore, we call Logical Fallacies, as being properly, violations of those rules of Reasoning which it is the province of Logic to lay down.

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Of these, however, one kind are more purely Logical, as exhibiting their fallaciousness by the bare form of the expression, without any regard to the meaning of the Terms: to which class belong: 1st. Undistributed Middle; 2d. Illicit Process; 3d. Negative Premises, or Affirmative Conclusion from a Negative Premiss, and vice versâ: to which may be added 4th. those which have palpably (i.e. expressed) more than three Terms.

cal Fallacies.

The other kind may be most properly called semi-logical; viz. all Semi-Logithe cases of ambiguous middle-Term except its non-distribution: for though in such cases the conclusion does not follow, and though the rules of Logic show that it does not, as soon as the ambiguity of the middle-Term is ascertained, yet the discovery and ascertainment of this ambiguity requires attention to the sense of the Term, and

In the same manner as we call that a criminal court in which crimes are judged.

knowledge of the Subject-matter; so that here, Logic teaches us not how to find the Fallacy, but only where to search for it, and on what principles to condemn it.

Accordingly it has been made a subject of bitter complaint against Logic, that it presupposes the most difficult point to be already accomplished, viz. the sense of the Terms to be ascertained. A similar objection might be urged against every other art in existence; e.g. against Agriculture, that all the precepts for the cultivation of land presuppose the possession of a farm; or against Perspective, that its rules are useless to a blind man. The objection is indeed peculiarly absurd when urged against Logic, because the object which it is blamed for not accomplishing cannot possibly be within the province of any one art whatever. Is it indeed possible or conceivable that there should be any method, science, or system, that should enable one to know the full and exact meaning of every term in existence? The utmost that can be done is to give some general rules that may assist us in this work; which is done in the first two chapters of Book II.* Nothing perhaps tends more to conceal from men their imperfect conception of the meaning of a term, than the circumstance of their from clear being able fully to comprehend a process of reasoning in which it is involved, without attaching any distinct meaning at all to that term; as is evident when X Y Z are used to stand for Terms, in a regular Syllogism. Thus a man may be familiarized with a term, and never find himself at a loss from not comprehending it; from which he will be very likely to infer that he does comprehend it, when perhaps he does not, but employs it vaguely and incorrectly; which leads to fallacious Reasoning and confusion. It must be owned, however, that many Logical writers have, in great measure, brought on themselves the reproach in question, by calling Logic "the right use of Reason," laying down "rules for gaining clear ideas," and such-like dλalwveía, as Aristotle calls it; (Rhet. Book I. Chap. II.)

Familiarity with a term distinct

apprehen

sion of its

meaning.

Material
Fallacies.

§ 3.

The remaining class (viz. where the Conclusion does follow from the Premises) may be called the Material, or Non-logical Fallacies: of these there are two kinds; 1st. when the Premises are such as ought not to have been assumed; 2d. when the conclusion is not the one required, but irrelevant; which Fallacy is commonly called "ignoratio elenchi, because your Argument is not the "elenchus " (i.e. proof of the contradictory) of your opponent's assertion, which it should be; but proves, instead of that, some other proposition resembling it.

4 The very author of the objection says, "This (the comprehension of the meaning of general Terms) is a study which every individual must carry on for himself; and of which no rules of Logic (how useful soever they may be in directing our labours) can supersede the neces

sity." D. Stewart, Phil. Vol. II. Chap. II. s. 2.

5 For it is manifest that the fault, if there be any, must be either 1st. in the Premises, or 2dly. in the Conclusion, or 3dly. in the Connexion between them.

Hence, since Logic defines what Contradiction is, some may choose
rather to range this with the Logical Fallacies, as it seems, so far,
to come under the jurisdiction of that Art. Nevertheless, it is per-
haps better to adhere to the original division, both on account of its
clearness, and also because few would be inclined to apply to the
Fallacy in question the accusation of being inconclusive, and conse-
quently illogical" reasoning; besides which, it seems an artificial
and circuitous way of speaking, to suppose in all cases an opponent
and a contradiction; the simple statement of the matter being this,-
I am required, by the circumstances of the case, (no matter why) to
prove a certain Conclusion; I prove, not that, but one which is
likely to be mistaken for it;-in this lies the Fallacy.

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elenchi.

It might be desirable therefore to lay aside the name of " "ignoratio Ignoratio elenchi," but that it is so generally adopted as to require some mention to be made of it. The other kind of Fallacies in the Matter

will comprehend (as far as the vague and obscure language of Logical writers will allow us to conjecture) the fallacy of "non causa Non causa

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pro causa, ‚" and that of "petitio principii. Of these, the former is pro causa. by them distinguished into "a non vera pro vera," and " a non tali pro tali;" this last would appear to mean arguing from a case not parallel as if it were so; which, in Logical language, is, having the suppressed Premiss false; for it is in that the parallelism is affirmed; and the "non vera pro vera" will in like manner signify the expressed Premiss being false; so that this Fallacy will turn out to be, in plain terms, neither more nor less than falsity (or unfair assumption) of a Premiss.

question.

The remaining kind, "petitio principii," ["begging the question,"] Begging the takes place when one of the Premises (whether true or false) is either plainly equivalent to the conclusion, or depends on that for its own reception. I have said "one of the Premises," because in all correct reasoning the two Premises taken together must imply and virtually assert the conclusion. It is not possible, however, to draw a precise line, generally, between this Fallacy and fair argument; since, to one person, that might be fair reasoning, which would be, to another, "begging the question;" inasmuch as, to the one, the Premiss might be more evident than the Conclusion; while, by the other, it would not be admitted, except as a consequence of the admission of the conclusion. The most plausible form of this Fallacy is arguing Arguing in in a circle; and the greater the circle the harder to detect.

$ 4.

There is no Fallacy that may not properly be included under some of the foregoing heads: those which in the Logical treatises are separately enumerated, and contradistinguished from these, being in reality instances of them, and therefore more properly enumerated in the subdivision thereof; as in the scheme annexed:

a circle.

Fallacies.

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Logical.

(4.6. when the fault is, strictly, in the very process of Reasoning; the Conclusion not following from the Premises.)

Semi-logical. (the middle term being ambiguous in sense.)

Non-Logical or Material.

(1. e. when the Conclusion does follow from the Premises.)

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in itself,

from the context,

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§ 5.

On each of the Fallacies which have been thus enumerated and distinguished, I propose to offer some more particular remarks; but before I proceed to this, it will be proper to premise two general observations, 1st. on the importance, and 2d. the difficulty, of detecting and describing Fallacies. Both have been already slightly alluded to; but it is requisite that they should here be somewhat more fully and distinctly set forth.

1st. It seems by most persons to be taken for granted that a Importance of detecting Fallacy is to be dreaded merely as a weapon fashioned and wielded Fallacies. by a skilful sophist; or, if they allow that a man may with honest intentions slide into one unconsciously, in the heat of argument, still they seem to suppose that where there is no dispute, there is no cause to dread Fallacy; whereas there is much danger, even in what may be called solitary reasoning, of sliding unawares into some Fallacy, by which one may be so far deceived as even to act upon the conclusion thus obtained. By "solitary reasoning" I mean the case in which one is not seeking for arguments to prove a given question, but labouring to elicit from one's previous stock of knowledge some useful inference.*

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words on

To select one from innumerable examples that might be cited, Influence of and of which some more will occur in the subsequent part of this thoughts. essay; it is not improbable that many indifferent sermons have been produced by the ambiguity of the word "plain." A young divine perceives the truth of the maxim, that "for the lower orders one's language cannot be too plain:" (i.e. clear and perspicuous, so as to require no learning nor ingenuity to understand it,) and when he proceeds to practice, the word "plain" indistinctly flits before him, as it were, and often checks him in the use of ornaments of style, such as metaphor, epithet, antithesis, &c., which are opposed to plainness" in a totally different sense of the word; being by no means necessarily adverse to perspicuity, but rather, in many cases, conducive to it; as may be seen in several of the clearest of our Lord's discourses, which are the very ones that are the most richly adorned with figurative language. So far indeed is an ornamented style from being unfit for the vulgar, that they are pleased with it even in excess. Yet the desire to be "plain," combined with that dim and confused notion which the ambiguity of the word produces in such as do not separate in their minds, and set before themselves, the two meanings, often causes them to write in a dry and bald style, which has no advantage in point of perspicuity, and is least of all suited to the taste of the vulgar. The above instance is not drawn from mere conjecture, but from actual experience of the fact. Another instance of the strong influence of words on our ideas

may

See the chapter on "inferring and proving," (Book IV. Ch. III.) in the Dissertation on the Province of Reasoning.

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