By examining the facts expressed in the invalid syllogism we have found that the fallacy consists of an undistributed middle term. This fallacy becomes obvious in some propositions in which the conclusion shows the absurdity of the reasoning process. If we could maintain that Herbert Lang is an orator because he is a man of great ability and all orators are men of great ability, we could argue with equal reason that he is a ground hog because he is an animal and all ground hogs are animals.
(2). The illicit process.
The illicit process of either the major or minor term in the syllogism consists of one of these terms appearing in the conclusion in a form essentially different from that in which it appeared in the major or minor premises. In this fallacy the major term which is in the affirmative form in the major premise becomes negative in the conclusion. The following fallacious syllogism illustrates this error:
1. All football men are strong.
2. Amos Buck is not a football man.
3. Therefore Amos Buck is not strong.
The fallacy is evident; the class of football men does not include all the strong men. There are some men who are not football men that are strong. The fact that Amos Buck is not included in the class of football men does not prove that he is not included in the larger class of strong men. To be more concrete let us again make use of the diagrams.
From the diagram on page [245] it is seen that the fact that all football men are strong and that Amos Buck is not a football man, does not prove anything regarding his strength. He may be within the class of strong men or he may be outside. Hence the syllogism is fallacious. Usually the fallacy is not so apparent as in the above illustration but by reducing the statements to syllogistic form in the manner indicated above the error becomes apparent.
The minor term in a syllogism sometimes appears in the minor premise as undistributed or particular and then appears in the conclusion as distributed or universal. This is another form of the illicit process. The same result follows when the minor term becomes either larger or smaller or in any way different in the conclusion from what it was in the minor premise. For example, a business man says, “I will not send my son to college because some college men are ‘sports’ and I detest ‘sports’.” This error in reasoning results from the failure to phrase each term in the same form throughout the syllogism. A scrutiny of the terms of the syllogism will therefore reveal the presence of this fallacy.
