e. Proofs that the knowledge shown came from Norsemen.

When these points are established, the first sub-proposition, with its underlying syllogism, may be looked upon as proved, and the next may be taken up. I have not studied the question of the discovery of America by the Norsemen closely enough to know that the line of proof given is the best possible, but it serves well enough to illustrate the general form of the skeleton of an argument. Each of the subordinate propositions must be divided and subdivided if necessary, until the divisions can be handled easily and proved conclusively; and the writer will do well to test the strength of his argument by making a complete chain of the syllogisms involved, seeing which rests upon another, so that the arrangement may be conformed to principles of natural sequence.

One important matter in reasoning is never to claim too much. Care must be taken not to put upon a proof a greater strain than it will bear. It is also an obvious rule that it is wise to insist upon no more than is absolutely needed to establish the proposition in hand. Sometimes it is wise to indicate that more might be proved, but in general the assent of the reader is to be treated as a bank account to be drawn upon as far as it is necessary, but in no case beyond the actual need of the occasion. It is well never to waste strength in proving more than is essential, and always to avoid a side issue as one shuns a road leading to sure destruction. Often it is a wise device in argumentation to establish a point and leave the reader to perceive its import. Here as everywhere a thing which the reader is led to do for himself is a hundred fold more effective than anything which can be done or said for him. The phrase, “Is it not possible that these facts prove this?” has won more converts than the boldest assertion: “These proofs make it impossible to doubt.” Man that is born of woman is born to obstinacy as the sparks fly upward, and if he be assured that he cannot or shall not doubt, he is apt to begin to doubt from simple contrariety. Yet it will not do to run any risk of leaving the reader in doubt as to what has been established by the arguments given. It is often necessary to insist that a proposition is proved. A victory is hardly recognized as a victory until the trumpets are blown, and an argument is scarcely concluded without some sort of a declaration of success.

Where the line is to be drawn between the extreme of leaving to the reader the perception of what is proved and that of insisting that a demonstration has been made must depend upon the audience addressed. The writer of an argument has especial need to be sure to whom he speaks. He must consider the knowledge of his audience, their views, and especially their prejudices. It is in relation to the last that there comes into play what it has been the fashion to call Persuasion. Although Argument is an appeal to the intellect, there are few chains of reasoning which fail to appeal also to the emotions. It is hardly possible to conceive of a discussion which will not to a greater or less degree touch the passions of those addressed. Much is effected by keeping in mind the natural prejudices of the reader, and so framing arguments that they shall appeal directly to the emotions by the personal or selfish nature of their deductions. An illustration is to be found in political harangues, which, while nominally devoted to proving the wisdom or advisability of some party measure, are really only clever attempts to convince that the measure is for the personal advantage of voters. This is, of course, the abuse of this form of argument. The legitimate use of this appeal to the passions is in the putting of reasoning sound and wholesome in itself into a form which shall captivate the hearer or reader. It is the lavishing upon the composition of all the graces of manner, of style, of ornament, which the writer can compass, to the end that the reader shall be attracted and inclined to accept the conclusions set down. Stevenson speaks of a somewhat different matter in words which are strictly applicable here:—

Whatever be the obscurities, whatever the intricacies of the argument, the neatness of the fabric must not suffer, or the artist has been proved unequal to his design. And, on the other hand, no form of words must be selected, no knot must be tied among the phrases, unless knot and word be precisely what is wanted to forward and illuminate the argument; for to fail in this is to swindle in the game.—Cont. Rev., vol. xlvii. (1885), p. 551.

Almost as often as with the establishment of our own reasoning, are we concerned in argument with endeavors to overthrow the logic of an opponent. Frequently it is necessary to refute views opposed to that which is being put forward. It is in general wise not to bring this in too soon. It is well to predispose the reader in favor of the conclusion to be defended, and then to take up contrary opinions. Sometimes a broad statement at the beginning to the effect that objections exist is politic; and in any case it is important that there be no slightest appearance of shirking or evading the issue. When the writer is conscious that the weight of popular sentiment or general opinion is against him, he may sometimes command attention and provoke interest by boldly plunging at once into an attack upon commonly received theories. Audacity always commands attention, and if it be reinforced by ability it is no less sure of admiration. A striking example of this method is to be found in Colonel Ingersoll’s attacks upon the Bible and religion. However one may be shocked by his violations of good taste, and whether one does or does not agree with his methods or his conclusions, it is impossible to deny his success as a speaker. The very boldness with which he has attacked has insured a hearing. This form of discussion calls for dash, courage, and confidence,—and it is sometimes the result of sheer impudence. Only he who has great powers and perfect command of them can reasonably hope to succeed here.

For answering the arguments of others, and indeed for the proper examination of one’s own, it is necessary to give attention to the numerous fallacies which may creep into reasoning, by design or by accident. These are to be completely mastered only by the minute study of logic; but some are so common that they should be considered here.

The first fallacy is that of the confusion of terms, such as that found in the attempt to prove the chef to be an interpreter of the beautiful, or in the question whether Whitman was a poet.

The second fallacy which in practical writing it is well to be on guard against is the non sequitur. There is much advanced as argument—as for instance in political editorials—where consecutiveness is confounded with causality. Post hoc ergo propter hoc is the phrase which sums this up: After this, therefore because of this. “We shall die after eating this meal, therefore this meal is the cause of our death,” is an example of this fallacy. Put in this way the absurdity is evident; but a genuine fallacy, lurking under words as the conventional serpent of school-girl compositions and of temperance orators lurks beneath flowers, is a different thing. Here is part of an editorial from one of the leading New York daily journals:

The vote of Senator X. is a striking illustration of the power of money among the law-makers of this great nation. The vigorous and unscrupulous support which has been given to this bill by Mr. A., the western billionaire, is known to everybody; and equally well known is the fact that hitherto Senator X. has been counted among the stanch opposers of the iniquitous measure. Senator X. is known to have had a private interview with Mr. A. on the evening before the vote was taken, and the result was evident when next morning the Senator gave his support to the bill which he had before steadily opposed.