Practical Argumentation by George K. Pattee (summer reading list .txt) 📖

To answer this question, first determine whether the facts to be established are such that any ordinary person can speak concerning them with reasonable accuracy, or whether they can be understood only by persons who have received special training. A landsman could well testify that a naval battle had occurred, but only a man with nautical training could accurately describe the maneuvers of the ships and tell just how the engagement progressed. A coal heaver’s description of a surgical operation would establish nothing, except perhaps the identity of the people and a few other general matters; only a person with a medical education could accurately describe the procedure. The testimony of any one but a naturalist would not even tend to prove the existence of an hitherto unknown species of animal life. A witness without technical knowledge cannot give reliable evidence on matters of a technical nature.

Then, if it is found that the witness does possess the necessary technical training, or that no previous training is necessary, still further test his ability to give reliable evidence by asking whether he has had ample opportunity for investigating the facts to the existence of which he testifies. For even a skilled player sitting in the first base bleachers at a baseball game to criticise an umpire’s decisions on balls and strikes is absurd; the opinion of a transient visitor to Panama on the methods used in digging the canal is not valuable; a traveler who has spent a single month in Japan cannot draw reliable conclusions on the merits and defects of its political structure. In not one of these cases has the opportunity for investigation been sufficient to render the witness able to give reliable evidence.

A current magazine in discussing the weakness of testimony that comes from incompetent witnesses says:—

Generalizations about the tastes and interests of the age are so easy that all except the most wary fall into them, and the world is full of off-hand opinions touching the condition of society and the state of the world, which are far more conspicuous for courage than for discretion. There are very few men or women in any particular period who know it intimately enough, and with sufficient insight and sympathy, to pass judgment upon it. One hears almost every day sweeping judgments about Americans, English, French, Germans, Chinese, and Japanese which are entirely valueless, unless they are based on a very broad and intimate knowledge of these various peoples, a knowledge which, in the nature of things, few people possess. The charming American girl who declared that, since gloves are cheaper in Paris, American civilization is a failure, may stand for a type of interesting and piquant oracles, to be heard with attention, but under no circumstances to be followed. Americans are so familiar with the European traveler who arrives and makes up his opinion over night in regard to men, morals, and manners in the Western world and have so often been the victim of this self-confident critic, that they ought not to repeat the same blunder in dealing with other peoples. [Footnote: The Outlook, July 20, 1907.]

In the court room, where witnesses are present and can be carefully examined by the lawyers on both sides, it is customary to apply both mental and physical tests. The witness who testifies to knowledge of some event that occurred a long time before is given a memory test; the senses, also, through which occurrences are perceived are frequently examined. But as writers and debaters in general seldom have the opportunity to apply tests of this sort to their sources of information, and as these tests are seldom important outside of the law courts, they are not taken up in detail in this book.

The second test of the source of evidence should be:—

(2) Is the witness willing to give an accurate account of the matter?

One important influence that may cause a witness to give false evidence is self-interest. Not only individuals, but social and industrial organizations, political parties, communities, and states are frequently swayed by this emotion to the extent of deliberately perverting the truth. The evidence found in newspapers and other publications is often false, or at least misleading, because it has been tampered with by those who put their selfish interests before all else. The owner of an industry protected by a high tariff would scarcely be considered a reliable witness in matters affecting tariff reform. The opinion of a railroad magnate on the subject of a compulsory two-cent rate law would not be considered as unbiased. No disinterested seeker after truth would accept the political conclusions of a newspaper owned by a politician or recognized as the organ of a certain party. In all such cases, self-interest may prompt the witness to make statements not in strict accordance with the truth. Perjury in the court room is not uncommon; falsehood elsewhere must be guarded against. The arguer should always carefully scrutinize the testimony of a witness that has any special interest in the matter for which evidence is being sought. Though the self-interest is strong, the witness may be willing to state the matter accurately; but, as long as human nature remains as it is, this willingness should not be taken for granted.

The third test of the source of evidence should be:—

(3) Is the witness prejudiced?

Another emotion that frequently keeps a witness from telling the exact truth is prejudice. Every one is familiar with instances of how this passion warps men’s morals and corrupts their judgment. If a man is prejudiced for or against a person or a system, he cannot be accepted as a trustworthy witness in matters where his prejudice comes into play. Should an economist known to favor socialism write a treatise advocating municipal ownership of public utilities, his evidence and his reasoning would not be convincing; it would be taken for granted that he looked at the subject through socialistic spectacles. A person who sets out with the expectation and intention of finding flaws in anything usually succeeds. Though he is willing to tell the exact truth, yet because of his prejudice he is sure to see only that which will coincide with his preconceived opinions. For this reason, political speeches and intensely partisan books and papers are invariably unreliable sources of evidence even though they are not intentionally dishonest.

The fourth test of the source of evidence is:—

(4) Does the witness have a good reputation for honesty and accuracy?

The human conscience is so constituted that many people deviate from the truth for no apparent reason whatever. Some are given to exaggeration; some habitually pretend to know that of which they are entirely ignorant; others are so inaccurate that everything they say is open to grave suspicion. If a witness is known to have been repeatedly dishonest or inaccurate in the past, little reliance should be placed in his testimony. “Yellow journalism,” which is largely the reflection of common rumor, affords constant examples of witnesses that give questionable evidence.

Ability and willingness to give exact evidence, an unprejudiced attitude, and a good reputation for honesty and accuracy are the qualities that should characterize the sources of evidence. If a writer or speaker is securing testimony from friends or acquaintances, the application of these tests is not difficult. If, however, the sources are books and periodicals, his work is harder; but to be successful, he must not shirk it. When one procures evidence from books, he should investigate the character and standing of the author. When one obtains it from signed articles in papers and magazines, he must consider both the author and the character of the publication. In the case of newspaper “stories” and editorials, one should find out on what general policy and principles the paper is conducted. A cautious arguer will always avoid, as far as he can, the use of evidence that comes from a doubtful source. If one finds that an opponent has used the testimony of questionable witnesses, he can, by exposing the fact, easily refute the argument.

NECESSITY OF STATING SOURCES. It sometimes happens that an arguer fails to state the source of his evidence. This omission is usually fatal to success. No one is likely to put much confidence in statements that are introduced by such flimsy preambles as, “A certain statesman has declared”; “I have read somewhere”; “An acquaintance told me.” Not only must evidence come from sources that seem good to the writer, but those sources must be satisfactory to the audience. In the last analysis the audience is the judge of what is credible and what is not. Moreover, if the evidence is of great importance, or is liable to be disputed, the arguer should show in a few words why the witness is especially reliable.

B. INTERNAL TESTS OF EVIDENCE

(1) Is the evidence consistent with (a) other evidence in the same argument; (b) known facts; (c) human experience?

The requirement that every separate bit of evidence in an argument shall be consistent with every other bit of evidence in the same argument is too well understood to need explanation. One familiar with courts of law knows that a witness who contradicts himself is not believed. Furthermore, if the testimony of several witnesses for the same side is inconsistent, the case for that side is materially weakened. So it is in general debate: the arguer who wishes to succeed must not use evidence that is self-contradictory. His proof must “hang together”; his facts must all go to establish the same conclusion.

A flagrant violation of this principle once occurred in a class-room debate. The speaker for the negative on the proposition, “Resolved, That freshmen should be ineligible for college teams,” said that such a rule would deprive the freshmen of much-needed physical exercise. Later on, he said that just as many freshmen would receive injuries under this rule as without it, since they would take part in equally dangerous contests as members of freshmen teams. This contradiction ruined his argument.

In the next place, evidence to be of any value whatever, must be consistent with what is known about the case. If an arguer is so careless as to make statements contradictory either to well-established facts or to facts easily proved, he cannot hope to attain the slightest measure of success. Only one guilty of gross neglect or absolute falsehood is likely to fall into such an error. At one time the story was circulated that, during his early life, Lincoln had been insane. In the following passage Ida M. Tarbell shows that the testimony on which this belief was founded is inconsistent with the known facts of the case, and is, therefore, palpably untrue:—

“Mr. Thornton went on to say that he knew beyond a doubt that the sensational account of Lincoln’s insanity was untrue, and he quoted from the House journal to show how it was impossible that, as Lamon says, using Herndon’s notes, ‘Lincoln went crazy as a loon, and did not attend the legislature in 1841-1842, for this reason’; or, as Herndon says, that he had to be watched constantly. According to the record taken from the journals of the House by Mr. Thornton, which have been verified in Springfield, Mr. Lincoln was in his seat in the House on that ‘fatal first of January’ when he is asserted to have been groping in the shadow of madness, and he was also there on the following day.”

Lincoln himself was an expert at detecting inconsistency wherever it existed. He won many of his lawsuits by the straightforward method of showing that the one or two vital statements on which the whole case of the opposition rested were false, inasmuch as they were inconsistent with well-established and incontrovertible facts. An instance of this sort is here described:—

The most damaging evidence was that of one Allen, who swore that he