In this so-called syllogism then we have a suppressed major of this form, "that which is true of some is true of all," which must mean either "everything which is true of some is true of all," or, "this one thing which is true of some is true of alL" In the former case, the suppressed major expresses a general proposition, which we must establish in order that our illation, which is logically correct, may be true materially ; but then this is not .the proposition which we pro fess to be desirous to establish, and, more than that, it cannot be established by the facts investigated and collected. If it means that this onelthing which is true of some is true of all, this is nothing more than to make the conclusion the major premiss, and so to conclude the conclusion from itself. It cannot be supposed that Dr. Whately has any such absurd meaning as this : but his language is capable of this meaning. He does however mean either this or the other ; and it is not easy to say which is the less logical meaning of the two.
A few more words seem necessary on another passage in Dr. Whately's work, by way of clearing the way to a right comprehension of the province of logic. It has been already observed that discourse or speech generally assumes the form of a syllogism with one of the premises suppressed; which is by many modern logicians called an enthymeme.* Dr. Whately observes that the enthymeme (the enthymeme of modern logicians) "is not strictly syllogistic, that is, its conclusiveness is not apparent from the mere form of the expression, without regard to the meaning of the terms ; because it is from that we form our judgment as to the truth of the suppressed premise. The expressed (qu. suppressed) premiss may be true, and yet the conclusion false." The reason here given why the (so-called) enthymeme is not strictly syllogistic is, that we form our judgment of the truth of the suppressed premiss from the meaning of the terms. This is a singular reason. The truth of the suppressed premise has nothing to do with the validity of the conclusion as an inference. If the suppressed premiss were expressed, the question as to the conclusion would be, not whether the suppressed premise were true but whether it necessitated the conclusion. If the conclusion is already made and one premiss only stated, the (ruth of the suppressed premiss is not the matter in question, but only what it is •' and when we have ascertained what the premiss must be in order that the conclusion may be valid as an inference, we may then inquire if the suppressed premiss is true. The
expressed premise cannot be true and the conclusion false, for the proper suppressed premiss is virtually involved in the conclusion and the expressed premiss. Besides, the mere form of the expression does indicate the suppressed premiss ; if it did not, the enthymeme, that is, the incomplete syllogism, the syllogism of common discourse, would be incapable of being expressed in the form of a complete syllogism. If we say A is c, because or for it is B which is the mere form of the expression, we see that the suppressed premise is, B is c, that is, n is contained in or is co-extensive with c ; and every person who can com prehend the notion of a containing whole and its contained parts will understand what is meant if is expressed in this form; A is con tained in c because A is contained in is. As if a man had found that any one thing could be contained in another (second) thing, and this other (second) thing were contained in a third, he would conclude mentally that this one thing was contained in the third ' • and the form of his expression would be, it is contained in the third because it is contained in the second, in which he would tacitly suppose that the second is contained in the third, and would then necessarily conclude that the first is contained in the third.
We are now in a condition to show what are the limits of pure logic, or of a pure logic. All propositions and all syllogisms are the subject of a pure logic only so 'fax as they have all something in common. They have only something in common so far as they are all capable of being reduced to a common form or forms; that is, a pure logic is formal only. Neither the syllogism nor its parts regard the matter, and the propositions which enter into the syllogism are only the object of logic so far as they are connected by is and is not. And since all propositions, when viewed solely as the parts of a syllogism, must be capable of being reduced to the same form or forms, it follows that all propositions as logical elements connected by is and is not arc only viewed in that way in which the reason does, and must because it does, view all things which are so presented to the mind independently of the matter, namely, with relation to the notion of a containing whole and contained parts.
If this exposition seem tedious, the fault is with those who, while they profess to teach pure logic, confound it both with an applied logic and with other things also.