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Two classes of

Arguments.

In distributing, then, the several kinds of Arguments, according to this division, it will be found convenient to lay down first two great classes, under one or other of which all can be brought; viz. first, such Arguments as might have been employed — not as arguments, but to account for the fact or principle maintained, supposing its truth granted secondly, such as could not be so employed. The former class (to which in this Treatise the name of “A priori" Argument will be confined) is manifestly Argument from Cause to Effect; since to account for any thing, signifies, to assign the Cause of it. The other class, of course, comprehends all other Arguments; of which there are several kinds, which will be mentioned hereafter.

The two sorts of proof which have been just spoken of, Aristotle seems to have intended to designate by the titles of Sr for the latter, and diór for the former; but he has not been so clear as could be wished in observing the distinction between them. The only decisive test by which to distinguish the Arguments which belong to the one, and to the other, of these classes, is, to ask the question, "Supposing the proposition in question to be admitted, would this statement here used as an Argument, serve to account for and explain the truth, or not?" It will then be readily referred to the former or to the latter class, according as the answer is in the affirmative or the negative; as, e. g. if a murder were imputed to any one on the grounds of his "having a hatred to the deceased, and an interest in his death," the Argument would belong to the former class; because, supposing his guilt to be admitted, and an inquiry to be made how he can commit the murder,

the circumstances just mentioned would serve to account for it; but not so, with respect to such an Argument as his "having blood on his clothes;" which would therefore be referred to the other class.

And here let it be observed, once for all, that when I speak of arguing from Cause to Effect, it is not intended to maintain the real and proper efficacy of what are called Physical Causes to produce their respective Effects, nor to enter into any discussion of the controversies which have been raised on that point; which would be foreign from the present purpose. The word "Cause," therefore, is to be understood as employed in the popular sense; as well as the phrase of "accounting for " any fact.

Argument from cause to effect.

As far, then, as any Cause, popularly speaking, has a tendency to produce a certain Effect, so far its existence is an Argument for that of the Effect. If the Cause be fully sufficient, and no impediments intervene, the Effect in question follows certainly; and the nearer we approach to this, the stronger the Argument.

This is the kind of Argument which produces (when short of absolute certainty) that species of the Probable which is usually called the "Plausible." On this

Plausibility.

subject Dr. Campbell has some valuable remarks in his “Philosophy of Rhetoric," (Book I. § 5. Ch. VII.) though he has been led into a good deal of perplexity, partly by not having logically analyzed the two species of probabilities he is treating of, and partly by departing, unnecessarily, from the ordinary use of terms, in treating of the Plausible as something distinct from the Probable, instead of regarding it as a species of Probability.*

*I do not mean, however, that every thing to which the term

This is the chief kind of Probability which poets, or other writers of fiction, aim at; and in such works it is often designated by the term "natural."* Writers of this class, as they aim not at producing belief, are allowed to take their "Causes" for granted, (i. e. to assume any hypothesis they please,) provided they make the Effects follow naturally; representing, that is, the personages of the fiction as acting, and the events as resulting, in the same manner as might have been expected, supposing the assumed circumstances to have been real. And hence, the great Father of Criti

"plausible" would apply would be in strict propriety called "probable;" as e. g. if we had fully ascertained some story that had been told us to be an imposition, we might still say, it was a "plausible" tale; though, subsequent to the detection, the word "probable" would not be so properly applied. But certainly common usage warrants the use of "probable" in many cases, on the ground of this plausibility alone; viz. the adequacy of some cause, known, or likely to exist, to produce the effect in question. I could have wished that there had been some other word to designate what I have called, after Dr. Campbell's example, the "plausible," because it sometimes suggests the idea of "untrue." But "likely," which, according to etymology, ought to be the suitable term, is often used to denote the "probable," generally.

When however we have clearly defined the technical sense in which we propose to employ a certain term, it may fairly be so taken, even though not invariably bearing that sense in common usage.

*It is also important for them, though not so essential, to keep clear of the improbable air produced by the introduction of events, which, though not unnatural, have a great preponderance of chances against them. The distinction between these two kinds of faults is pointed out in a passage in the Quarterly Review, for which see Appendix, [B.]

† For some remarks on this point, see the preface to a late (purified) edition of the "Tales of the Genii."

cism establishes his paradoxical maxim, that impossibilities which appear probable, are to be preferred to possibilities which appear improbable. For, as he justly observes, the impossibility of the hypothesis, as e. g. in Homer, the familiar intercourse of gods with mortals, is no bar to the kind of Probability (i. e. Verisimilitude) required, if those mortals are represented as acting in the manner men naturally would have done under those circumstances.

The Probability, then, which the writer of fiction aims at, has, for the reason just mentioned, no tendency to produce a particular, but only a general, belief; i. e. not that these particular events actually took place, but that such are likely, generally, to take place under such circumstances: this kind of belief (unconsciously entertained) being necessary, and all that is necessary, to produce that sympathetic feeling which is the writer's object. In Argumentative Compositions, however, as the object of course is to produce conviction as to the particular point in question, the Causes from which our Arguments are drawn must be such as are either admitted, or may be proved, to be actually existing, or likely to exist.

The unnatural mistaken for natural.

It is worthy of remark, in reference to this kind of Probability—the "Plausible" or "Natural" — that men are apt to judge amiss of situations, persons, and circumstances, concerning which they have no exact knowledge, by applying to these the measure of their own feelings and experience : + the result of which is, that a correct account of these will

* On which ground Aristotle contends that the end of Fiction is more Philosophical than that of History, since it aims at general, instead of particular, Truth.

† See Part II. Ch. II. § 2.

often appear to them unnatural, and an erroneous one, natural. E. G. A person born with the usual endowments of the senses, is apt to attribute to the blind-born, and the deaf-mutes, such habits of thought, and such a state of mind, as his own would be, if he were to become deaf or blind, or to be left in the dark; which would be very wide of the truth. That a man born blind would not, on obtaining sight, know apart, on seeing them, a ball, and a cube, which he had been accustomed to handle, nor distinguish the dog from the cat, would appear to most persons unacquainted with the result of experiments, much less "natural" than the reverse. So it is also with those brought up free, in reference to the feelings and habits of thought of born-slaves; † with civilized men, in reference to savages; and of men living in Society, in reference to one who passes whole years in total solitude. I have no doubt that the admirable fiction of Robinson Crusoe would have been not only much less amusing, but, to most

* See an account, in a Note to the First Series of Essays, of a blind youth couched by Mr. Cheselden.

†This has, in various ways, proved an obstacle to the abolition of slavery. It has also caused great difficulty to some readers of the Book of Exodus.

In the fifth Lecture on Political Economy (an extract from which is subjoined in the Appendix, Note C,) I have noticed the descriptions usually given of the origin of Civilization, which are generally received as perfectly natural, though they are, as I have shown, such as never were, or can be realized. I mean, in the English, not in the American sense of the word "realize." To realize a scheme, &c., means, with us, to make it "real," to "carry it into effect;' with the Americans it means to "form a strong and vivid conception of it." I acknowledge the want, in our language, of a single word, adequately expressing this: but circumlocution is better than ambiguity.