Thus it is in debate; each debater must do his best both to build up his own argument and to destroy his opponent's.

To handle refutation successfully, either in written argument or in debate, one must know what to refute and what to leave alone. The general rule governing this matter is: _Refute only those arguments which are essential to the proof of the other side_. All trivial ideas, even all misstatements which if refuted would not destroy any fundamental process of an opponent's proof, should pa.s.s unnoticed. To mention them means waste of time and effort. It is not uncommon for a debater to make trivial errors intentionally, in the hope that his opponent will consume valuable time in refuting them and thus allow his main argument to go unscathed. When this stratagem succeeds, the one who made the mistakes can acknowledge that he was wrong in those unimportant details, and yet show that his fundamental arguments have not been overthrown. While arguing on a political question, an intercollegiate debater once laid considerable stress on an opinion expressed by Woodrow Wilson, "President," as he stated, "of Harvard University." His opponent, of course, might have held this statement up to ridicule, but such an exposure would have been impolitic, in that it would have in no wise impaired the value of Mr. Wilson's opinion as evidence. Another debater, not so wise, once spent considerable time in correcting an opponent who had said that the Steel Trust was formed in 1891 instead of in 1901, as was the case. As these dates had no vital bearing on the question at issue, the error should have been allowed to pa.s.s. The temptation to point out the flaws that are most obvious is always great, but unless by so doing one can knock out the props on which an opponent's proof rests, such an attack accomplishes nothing.

Another common error in refutation consists in "answering one's self."

A person is guilty of this fault whenever he misstates an opponent's argument, either because he does not understand it or through design, and then refutes this misstatement. The folly of such procedure is made apparent by merely calling attention to the fact that the original argument has been garbled but in no wise refuted, An opponent can convict the one who has "answered himself" either of unpardonable ignorance about the subject or of downright dishonesty.

To guard against these errors of refuting unimportant details and of "answering one's self," it is always well to reduce an opponent's argument to the form of a brief. If the argument is in print, this task is comparatively simple; if the argument is oral, the task will be harder but will still present no serious difficulties to one who is used to drawing briefs. When all the ideas have been arranged in the form of headings and subheadings, and the relation between the ideas has been indicated by means of numbers and letters, then the arguer can quickly decide what points he ought to refute and what ones he can refute.

It goes without saying that the headings marked with the Roman numerals contain the most important ideas, and should, therefore, be overthrown as far as possible. There are three ways of disposing of them: one way is to state that the headings are false and then bring on new proof to show their falsity; the second way is to call attention to the subheadings with which the opponent has bolstered up the main headings, and then, by proving these subheads false, allow the main heads to fall to the ground; the third way is to admit that the subheads are true and then show that the inferences drawn from them are unwarranted.

To ill.u.s.trate: A part of an argument on the affirmative side of the proposition, "_Resolved_, That students in American colleges should be excused from final examinations in all subjects in which they have attained a daily grade of at least eighty-five per cent.,"

might be reduced to the following brief form:--

I. This rule would be of great intellectual benefit to college students, for

A. They would master their work more thoroughly, because

1. They would study harder during the term.

The first method of overthrowing the heading indicated by (I) would be to attack it directly. This attack might consist of opinions of prominent educators who, on theoretical grounds, do not believe an intellectual benefit would result from the adoption of such a rule; of the opinions of educators who have tried the rule and declare that it is an intellectual detriment; and of a course of reasoning which would show that this system would rob the students exempted of the great intellectual benefit that is derived from the preparation for an examination and from the taking of an examination.

The second method would be to show that (1) is not true; therefore (A) would be false, and (I) would be left entirely unsupported.

Under the third method the arguer would admit the truth of (1), but would deny that the truth of (A) is established by it; therefore (I) would be unsupported.

Whenever a subheading is attacked, it is always very essential to show that the attack is made simply because this subheading serves as a foundation for the main heading. In this particular argument, refutation according to the second and third methods might read about as follows: "The contention of the affirmative that the eighty-five per cent. rule should be adopted because it would result in an intellectual improvement among college students, rests on the supposition that students would study harder during the term, and for that reason would more thoroughly master their subjects. This reasoning is erroneous because, in the first place, as I will show, but very few students, if any, would study harder during the term; and, in the second place, even if they did, those exempted would not have mastered their work so completely at the end of the year as they would have if they had taken an examination."

From the preceding, it is apparent that refutation consists of discrediting evidence and attacking reasoning. The ways to overthrow evidence will be considered first.

EVIDENCE.

It is taken for granted that the evidence mustered by the opponent is sufficient, if not overthrown, to establish his side of the discussion. Of course, if enough evidence for this purpose is lacking, one has only to call attention to this fundamental weakness in order to overthrow the argument then and there. The rules, therefore, for testing evidence a.s.sume that the opponent has cited facts that, if not combated, will establish his case.

These tests are the same as those given in Chapter VI; a hasty review of them, however, may be serviceable at this point.

I. Tests of the sources of evidence.

A. Is the witness competent to give a trustworthy account of the matter?

B. Is the witness willing to give an accurate account?

1. Does he have any personal interest in the case?

C. Is the witness prejudiced?

D. Does the witness have a good reputation for honesty and accuracy?

II. Internal tests of evidence.

A. Is the evidence consistent (a) with itself, (b) with known facts, (c) with human experience?

B. Is it first-hand evidence?

C. Can the evidence be cla.s.sed as especially valuable?

1. Does it consist of hurtful admissions?

2. Is it undesigned evidence?

3. Is it negative evidence?

III. Test of argument from authority.

A. Is the witness an acknowledged authority on the subject about which he testifies?

To overthrow or weaken argument from authority, one may either discredit its source or bring to light some inconsistency in the statement itself. Usually the former method alone is possible. To accomplish this result, one may show that the witness spoke from insufficient knowledge of the matter, or was prejudiced, or had some personal interest in the case. Counter authority will also be of a.s.sistance. The following quotation taken from a college debate furnishes the student a good example of how to handle this sort of refutation.

"The argument has been advanced that the South does not need the foreign laborer, and this argument has been supported by the words of Mr. Prescott F. Hall. We would call the attention of the audience and the judges to the fact that since Prescott F. Hall is Secretary of the Immigration Restriction League, it would be to his interest to make this a.s.sertion. Why do not our opponents refer to impartial and unprejudiced men, men like Dr. Allen McLaughlin, a United States immigration official, who makes just the opposite statement?"

REASONING.

I. Induction.

A. Have enough instances of the cla.s.s under consideration been investigated to establish the existence of a general law?

B. Have enough instances been investigated to establish the probable existence of a general law?

II. Deduction.

A. Are both premises true?

B. Is the fact stated in the minor premise an instance of the general law expressed in the major premise?

III. Antecedent probability.

A. Is the a.s.signed cause of sufficient strength to produce the alleged effect?

B. May some other cause intervene and prevent the action of the a.s.signed cause?

IV. Sign.

A. Argument from effect to cause.

1. Is the a.s.signed cause adequate to produce the observed effect?

2. Could the observed effect have resulted from any other cause than the one a.s.signed?