Here it is possible that 'All Popes' may agree with precisely that part of the term 'man,' of which it is not known whether it agrees with 'fallible' or not. § 586. The violation of Rule 4 is known as the Fallacy of Illicit Process. If the major term is distributed in the conclusion, not having been distributed in the premiss, we have what is called Illicit Process of the Major; if the same is the case with the minor term, we have Illicit Process of the Minor. § 587. The reason for this rule is that if a term be used in its whole extent in the conclusion, which was not so used in the premiss in which it occurred, we would be arguing from the part to the whole. It is the same sort of fallacy which we found to underlie the simple conversion of an A proposition. § 588. Take for instance the following-- All learned men go mad. John is not a learned man. .'. John will not go mad. In the conclusion 'John' is excluded from the whole class of persons who go mad, whereas in the premisses, granting that all learned men go mad, it has not been said that they are all the men who do so. We have here an illicit process of the major term. § 589. Or again take the following-- All Radicals are covetous. All Radicals are poor. .'. All poor men are covetous. The conclusion here is certainly not warranted by our premisses. For in them we spoke only of some poor men, since the predicate of an affirmative proposition is undistributed. § 590. Rule 5 is simply another way of stating the third axiom of mediate inference. To know that two terms disagree with the same third term gives us no ground for any inference as to whether they agree or disagree with one another, e.g. Ruminants are not oviparous. Sheep are not oviparous. For ought that can be inferred from the premisses, sheep may or may not be ruminants. § 591. This rule may sometimes be violated in appearance, though not in reality. For instance, the following is perfectly legitimate reasoning. No remedy for corruption is effectual that does not render it useless. Nothing but the ballot renders corruption useless. .'. Nothing but the ballot is an effectual remedy for corruption. But on looking into this we find that there are four terms-- No not-A is B. No not-C is A. .'. No not-C is B. The violation of Rule 5 is here rendered possible by the additional violation of Rule 2. In order to have the middle term the same in both premisses we are obliged to make the minor affirmative, thus No not-A is B. All not-C is not-A. .'. No not-C is B. No remedy that fails to render corruption useless is effectual. All but the ballot fails to render corruption useless. .'. Nothing but the ballot is effectual.