Pagina-afbeeldingen
PDF
ePub

variance with the opinions of others, we are to m.ike truth our object. The opposite of a desire of the truth is

a a wish to decide the subject of dispute in one way or another, independently of a just consideration of the evidence. The foundation of such a preference of one result to another is in general the prejudices of interest and passion; and these are the great enemies of truth. Whenever we are under their influence, we form a different estimation of testimony and of other sources of evidence from what we should do under other circumstances; and at such times they can hardly fail to lead us to false results.—This rule is important on all occasions of reasoning whatever, but particularly in public debate ; because at such times the presence of others and the love of victory combine with other unpropitious influences to. induce men to forget or to disregard the claims which truth is always entitled to enforce.

299. Care to be used in correctly stating the subject of discussion.

(II.) Another rule in the prosecution of an argument is, that the question under debate is to be fairly and correctly stated. The matter in controversy may be stated in such a way as to include, in the

very

enunciation of it, something taken for granted, which must necessarily lead to a decision in favour of one of the opponents. But this amounts to begging the question, a species of fallacy or sophism upon which we shall again have occasion to remark.-Sometimes the subject of discussion is stated so carelessly, that the true point at issue is wholly left out. It may be proper, therefore, in many cases to adopt the practice of special pleaders, and first to ascertain all the points in which the opponents agree, and those in which they differ. And then they can hardly fail of directing their arguments to what is truly the subject of contention.

In order that there may not be a possibility of misunderstanding here, dialecticians should aim to have clear ideas of everything stated in the question which has an intimate connexion with the point at issue. Subordinate parts of the question, and even particular words, are to be examined. If, for instance, the statement affirm or deny anything in regard to the qualities or properties of mate

rial bodies, it is incumbent upon us to possess as clear ideas as possible both of the object in general and of those properties or qualities in particular. Similar remarks will apply to other subjects of inquiry of whatever kind.

Ø 300. Consider the kind of evidence applicable to the subject. (III.) As one subject clearly admits of the application of one species of evidence, while another as clearly requires evidence of a different kind, we are thence ena. bled to lay down this rule, viz., We are to consider what kind of evidence is appropriate to the question under discussion.

When the inquiry is one of a purely abstract nature, and all the propositions involved in the reasoning are of the same kind, then we have the evidence of Intuition or intuitive perception; and the conclusion, for reasons already mentioned, is certain.—In the examination of the properties of material bodies, we depend originally on the evidence of the Senses, which gives a character and strength to our belief according to the circumstances under which the objects are presented to them. In judging of those facts in events and in the conduct of men which have not come under our own observation, we rely on Testimony. This source of belief causes probability in a greater or less degree, according as the testimony is from one or more, given by a person who understands the subject to which it relates, or not, &c.—And again, some subjects admit of the evidence of Induction, and in respect to others we have no other aids than the less authoritative reasonings from Analogy. In other cases, the evidence is wholly made up of various incidental circumstances which are found to have relation to the sub. ject in hand, and which affect the belief in different degrees and for various causes.

And hence, as the sources of belief, as well as the belief itself, have an intimate connexion with the subject before us, they ought to be taken into consideration. The evidence should be appropriate to the question. But if the question admit of more than one kind of evidence, then all are entitled to their due weight.

Ø 301. Reject the aid of false arguments or sophisms (IV.) There is a species of false reasoning which we call a SOPHISM. - A sophism is an argument which contains some secret fallacy under the general appearance of correctness. The aid of such arguments, which are calculated to deceive, and are, in general, inconsistent with a love of the truth, should be rejected.

(1.) IGNORATIO ELENCHI, or misapprehension of the question, is one instance of sophism. It exists when, from some misunderstanding of the terms and phrases that are employed, the arguments advanced do not truly apply to the point in debate. It was a doctrine, for instance, of some of the early philosophic teachers of Greece, that there is but one principle of things. Aristotle, understanding by the word principle what we commonly express by the word ELEMENT, attempted to show the contrary, viz., that the elements are not one, but many, thus incurring the imputation of IGNORATIO ELENCHI; for those who held the doctrine which was thus subjected to his animadversion, had reference, not to the form, but the cause of things; not to any doctrine of elementary material particles, but to the intellectual origin, the creative mind, the Supreme Being, whom, as the PRINCIPLE (that is, as the beginning and the support of things), they maintained to be one. (2.) PETITIO PRINCIPII

, or begging of the question, is another instance of sophism. This sophism is found whenever the disputant offers in proof of a proposition, the proposition itself in other words. The following has been given as an instance of this fallacy in reasoning : A person attempts to prove that God is eternal by maintaining that his existence is without beginning and without end. Here the proof which is offered, and the proposition itself which is to be proved, are essentially the same.—When we are told that opium causes sleep beca'use it has a soporific quality, or that grass grows by means of its vegetative power, the same thing is repeated in other terms.—This fallacy is very frequently practised; and a little care in detecting it would spoil many a fine saying, as well as deface many an elaborate argument

* La Logique ou l'Art de Penser (Port Royale), pt. iii., chap xix

a

[ocr errors]

What is called arguing in a circle is a species of sophism very nearly related to the above. It consists in making two propositions reciprocally pror : each other.

3 (3.) NON CAUSA PRO CAUSA, or the assignation of a false cause. -People are unwilling to be thought ignorant; rather than be thought so, they will impose on the credulity of their fellow-men, and sometimes on themselves, by assigning false causes of events. Nothing is more common than this sophism among illiterate people; pride is not diminished by deficiency of learning, and such people, therefore, must gratify it by assigning such causes of events as they find nearest at hand. Hence, when the appearance of a comet is followed by a famine or a war, they are disposed to consider it as the cause of those calamities. If a person have committed some flagrant

. crime, and shortly after suffer some heavy distress, it is no uncommon thing to hear the former assigned as the direct and the sole cause of the latter.—This was the fallacy which historians have ascribed to the Indians of Paraguay, who supposed the baptismal ceremony to be the cause of death, because the Jesuit missionaries, whenever opportunity afforded, administered it to dying infants, and to adults in the last stage of disease.

(4.) Another species of sophistry is called FALLACIA ACCIDENTIS.—We fall into this kind of false reasoning whenever we give an opinion concerning the general nature of a thing from some accidental circumstance. Thus, the Christian religion has been made the pretext for persecutions, and has, in consequence, been the source of much suffering ; but it is a sophism to conclude that it is, on the whole, not a great good to the human race, because it has been attended with this perversion. Again, if a medicine have operated in a particular case unfavourably, or in another case have operated very favourably, the universal rejection or reception of it, in consequence of the favourable or unfavcurable result in a particular instance, would be a hasty and fallacious induction of essentially the same sort. That is, the general

. , nature of the thing is estimated from a circumstance which may be wholly accidental.

0 302 Fallacia equivocationis, or the use of equivocal terms and phrases.

(V.) It is a further direction of much practical importance, that the reasoner should be careful, in the use of language, to express everything with plainness and precision ; and especially never attempt to prejudice the cause of truth, and snatch a surreptitious victory by the use of an equivocal phraseology. No man of an enlarged and cultivated mind can be ignorant that multitudes of words in every language admit of diversities of signification. There are found also in all languages many words, which sometimes agree with each other, and sometimes differ in signification, according to the connexion in which they appear, and their particular application. There is, therefore, undoubtedly an opportunity, if any should be disposed to embrace it, of employing equivocal terms, equivocal phrases, and perplexed and mysterious combinations of speech, and thus hiding themselves from the penetrating light of truth, under cover of a mist of their own raising.

No man, whose sole object is truth and justice, will resort to such a discreditable subterfuge. If in reasoning he finds himself inadvertently employing words of an equivocal signification, it will be a first care with him to guard against the misapprehensions likely to result from that source. He will explain so precisely the sense in which he uses the doubtful terms as to leave no probability of cavilling and mistake.

And besides the invaluable reputation of a man of honour and justice, he will in this way realize results in respect to his own intellectual character of the most beneficial nature. The practice of verbal criticism, as it has

. been called (that is, of discriminating readily and accurately the meaning of words), will result in a HABIT, giving to the dialectician a vast power over his opponent, who has not been trained to the making of such nice discriminations. There will be a keenness of intellectual perception which, while it helps to untie the perplexities of langauge, at the same time resolves the perplexities of thought; separating meaning from meaning, and dividing truth from falsehood in those cases where at first sight it appeared to be impossible. But it is a power

a

« VorigeDoorgaan »