which have been given should lead him to appreciate fully the fact that analogy has two well defined uses aside from its value as proof of the truth or falsity of a conclusion. In the first place it is a most important agency in suggesting conclusions which may be verified or discredited by other processes of reasoning. In the second place it affords a most valuable method of stating a case so plainly that even the most ignorant may understand. A striking analogy makes a most vivid impression on the mind and is retained long after more formal processes of reasoning are forgotten.

SUMMARY OF THE REQUIREMENTS FOR AN ARGUMENT FROM ANALOGY I. The two factors in the analogy must be alike in all particulars which affect the conclusion.

II. The alleged facts upon which the analogy is based must be true.

III. The conclusion established by analogy should whenever possible be verified by positive evidence.

EXERCISES IN ANALOGY

I. Apply the requirements for validity to each of the arguments from analogy quoted in this last chapter.

II. Suggest arguments from analogy in support of each of the following conclusions:

1. College students should be allowed to select their own courses of study.

2. A course in public speaking is a necessity for those who expect to teach.

3. The greatest moral strength is fostered among many temp

tations.

4. An inheritance tax is an exceedingly just method of taxation.

5. All colleges should be coëducational.

6. Military drill should be compulsory for all college freshmen. 7. The use of clear and correct English is a prerequisite to

success in any profession.

III. Write an argument from analogy in support of one of the propositions given in the appendix.

CHAPTER V

FALLACIES

A fallacy is an error in the argumentative process. It may arise from a mistake in the process of reasoning or from a mistake regarding the facts upon which the reasoning is based. The task of detecting and eliminating fallacies in his own argument and of detecting and exposing fallacies in the argument of his opponent is one of the most important phases of a debater's work."

Self-evident fallacies are few. A fallacy is almost always concealed under cover of language which makes it appear in the guise of valid reasoning. It is usually embedded in an otherwise sound argumentative structure. To detect and to separate it from that which is entirely trustworthy is one of the severest tests of argumentative skill. Just as in a mathematical computation one wrong figure will invalidate the accuracy of the result though all the other figures be correct, so will one false statement in an argument produce the same disastrous effect. A fallacy may occupy but a very small part of the argument and yet be fatal to the solidity of the entire structure. It may consist of only one sentence in several pages of printed matter. It may be but a single statement which makes an unwarranted transition or assumption. Nevertheless it is as fatal to the argument as though it comprised a greater part of the entire discussion.

While an opponent may cover up a fallacy with the deliberate intention to deceive, yet the existence of most fallacies is not suspected by those who use them. Therefore the use of fallacious arguments is seldom evidence of dishonesty

but is almost always the result of careless reasoning or inability to detect and remedy such errors. To classify fallacies into groups for the purpose of discussion is a most difficult undertaking. Any division that can be made will not prove all inclusive and all exclusive in practical application. Hard and fast divisions are sure to overlap, and a particular fallacy may be treated under one division or another according to the standpoint of the student and the combination of circumstances under which it exists. For the purpose of this discussion we shall divide fallacies according to the kind of argument in which they occur and according to the form in which they are usually found. This method of division will best serve our practical object, which is the detecting and eliminating of fallacies.

I. Fallacies of Induction.

In a perfect induction a fallacy may be detected by scrutinizing the conclusion to make sure that it includes only the specific instances upon which it is based, and then examining each of these specific instances to see that it is true as a matter of fact. If the conclusion includes more than the facts warrant or if the alleged facts are false the perfect induction is fallacious.

In searching for fallacies in an imperfect induction the rules which have already been pointed out as governing the construction of such an inductive argument should be applied. In order to make a systematic search for fallacies in arguments involving this kind of reasoning, the following steps should be taken.

1. The number of specific instances relied upon to support the inductive conclusion should be determined.

It is comparatively easy to determine the number of incidents claimed to support the conclusion, provided they are

all stated in the argument. In such a case the searcher for fallacies merely counts these incidents and passes on to the next step in his investigation. Seldom, however, is the task so easy. In most arguments the writer or speaker extends his conclusion far beyond the actual facts offered in its support. Often the speaker states that "hundreds of other cases," or "incidents too numerous to mention," or “thousands of similar cases," etc., can be produced to show the validity of the induction. The debater should never be overawed by such sweeping statements or allow them to cause him to cease his search for fallacies. He must be insistent in his demand that the number of incidents upon which the conclusion is based be exactly stated or at least that the number be shown as large enough to offset the probability of coincidence. The fallacy of the induction can then be shown to exist by pointing out that the number of incidents in support of the induction is not sufficiently great to warrant its acceptance.

2. The class of persons, events, or things about which the induction is made should be scrutinized with a view to determining whether it is homogeneous.

The discussion of this requirement for a valid imperfect induction which has been previously given will make plain the nature of the investigation under it. A fallacy may be exposed in such an argument by showing that the class of persons, events, or things about which the induction is made is j not homogeneous in respect to the particular about which the conclusion is stated.

3. Whether or not the specific instances cited in support of the conclusion are fair examples should be determined.

It is usually easier to detect unfair examples in an opponent's argument than in one of the debater's own construc

tion. The person who uses an induction is almost always prejudiced in favor of the instances which support it, but to the unprejudiced mind the fairness of a given example is not hard to determine. It is therefore important that the investigator assume an unprejudiced attitude towards the examples offered as representative of the class about which the induction is made. The existence of a fallacy in an argument based upon an imperfect induction may be revealed by showing that the specific instances cited in support of the conclusion are not fair examples.

4. A search should be made for exceptions to the rule stated by the induction.

One of the most effective ways to overthrow a generalization is to present exceptions. Even the existence of one exception will greatly weaken the effect of a conclusion, while several exceptions, clearly established, will entirely destroy it. To prove the existence of more exceptions to the rule than there are instances supporting it is to prove it entirely fallacious. The search for exceptions should be made by the same means employed in finding instances to support the induction. The fallacy of an induction may be shown by proving the existence of exceptions to the rule which it states.

5. The induction should be examined with a view to determining its reasonableness.

An induction which appears on its face to be contrary to usual experience is not an effective instrument of persuasion. By showing that it is contrary to natural law or that no process of reasoning other than induction can be made to uphold it, the student may weaken its force. If clear proof of its validity can be established in this way it is not necessary that other methods of showing a fallacy be introduced. The fallacy of an induction may be established by clear proof of its unreasonableness.