Cursus Philosophicus Thomisticus, Prima Pars Artis Logicae

Before proposing the difficulties, I ASSUME three things. First, the common understanding of the intellect, when it uses a term, can apply two terms to one another in two ways. First, by a simple application in a general way: what has the character of form is applied to what has the character of matter and subject. This is called a simple and absolute application because it is made not through a relation or modification, but absolutely and simply. Second, one term can be applied to another not absolutely and simply, but through some relation, modification, or formality of one to the formality of the other. By reason of this, one is verified of the other precisely as it stands under that modification and not otherwise; if it is varied or changed, the consequence is vitiated. We call this kind of application appellation in a special sense, as when I say, “Peter is a great doctor,” where greatness is not applied to Peter absolutely but with respect to medicine.

Second, it follows from this that the view of some recent writers is false: they define appellation as a denomination by which one term denominates another, and preserve it in the application by which the formal aspect of one term is applied to the material aspect of another, as in “A human being sits,” “A human being runs,” and so on. But this view confuses the general application of a predicate to a subject with the special logical property called appellation. This is clearly false. The application and use of a term occur in different ways when a predicate is applied simply and absolutely to a subject taken materially, and when it is applied only as it stands under some relation and modification. This pertains to signifying truth in different ways; a variation of this kind makes a consequence defective and invalid. Therefore appellation, or this special kind of application, must receive special consideration in logic and introduces a special logical property, which we call appellation. For example, this does not follow: “Peter is a great doctor; therefore Peter is great absolutely.”

Third, the rules of appellation set out in the text must be recalled, both those concerning real appellation and those concerning appellation of reason.¹ A special difficulty is added in real appellation concerning numerical terms when they are added to a substantive or an adjective. When a numerical term is added to a substantive term, it is said to number supposits by reason of the form; appellation therefore intervenes, because supposits are not numbered unless they are numbered according to the multiplication of forms. The rule does not say that forms are numbered, but that supposits are numbered by reason of forms. Thus the supposits must be numbered, and the forms themselves must be the reason for numbering; if there are not several supposits, the rule does not apply. It concerns substantial form according to its natural mode—that is, as bringing its supposit with it and subsisting. Thus, for there to be three human beings, three humanities are required; for there to be three gods, three deities. For adjectives to be numbered, however, it suffices that the supposits be multiplied, even if the forms added are not multiplied and only their denomination is. For example, if one whiteness were in several supposits, they would be called several white things, because this plurality results not from multiplication of whiteness but from multiplication of its addition and denomination.

THEREFORE, against the first rule one can argue that appellation occurs even if the terms are not placed on the side of the same extreme; therefore the rule is false.

The antecedent is clear: In “A white thing is intense,” “A white thing disperses sight,” and “Christ, as man, is a creature,” there is appellation to the subjects from the side of the predicate. For the sense is that Christ is a creature by reason of his humanity; otherwise, if the predicate were applied to the supposit, the proposition would be false. Likewise, in “This white thing is intense,” a defective consequence can arise from a mere variation of appellation, as when one says, “This white thing is intense; this white thing is similar; therefore what is similar is intense.” This consequence is invalid solely through a defect of appellation; therefore this shows that appellation intervenes. When one says, “A white thing disperses sight,” the sense is that it does so by reason of the formal aspect signified in “white”; otherwise the proposition would not be essential.

The same argument can be made about “The essence is generating in divine things.” This proposition is false because “generating” is applied to the signification of essence, not to its material and identical signification. For if it were applied to the identical and material signification of the divine essence, the proposition would be true: it would be verified of the Father, who is identically the divine essence.

This is confirmed because the rule does not hold for appellation of reason. When I say, “A human being is a species,” appellation intervenes, yet the terms are not placed on the side of the same extreme; therefore the rule does not hold for real appellation either.

WE REPLY that the rule is understood of formal and express appellation, not appellation that is, as it were, virtual and equivalent. When I say, “A white thing disperses sight,” “A white thing is intense,” and so on, how an application is made or signified to be made is one thing, and how something is verified in reality is another. On the side of the mode of signifying, the application of one term to another is not signified by appellation; only the simple application of predicate to subject is signified. But since the proposition cannot be verified except through some formal account belonging to the side of the subject, it is said to have appellation virtually and equivalently. Thus in these and similar consequences there is a defect of appellation that is, as it were, virtual, arising from a variation between two supposits, as it were, signified on the side of the subject: the white thing insofar as white and the white thing insofar as similar. These are as it were two logical supposits, although materially and physically there is one; changing from one to the other changes the consequence. Express appellation, however, is signified and posited only as the rule says, when the terms are placed on the side of the same extreme. In the proposition “The essence generates,” there is no appellation but a simple application of predicate to subject. Since the subject does not signify a person or supposit for one but signifies only the essence, the proposition is false. Although the essence is identically and materially the same as the person, this identity is on the side of the thing signified, not in the mode of signifying of the term “essence.” Since it does not signify a person² a personal act is not verified of it.

To the confirmation we reply that the rule speaks only of real appellation, not appellation of reason. For when a predicate is of second intention and is said of a first intention or its foundation, to which it belongs, the subject or foundation itself is signified under a state capable of that intention: the state of precision and intellectual apprehension, under which alone such a predicate can belong to it. Since it signifies that precision on the side of the subject, it is posited sufficiently to produce appellation, because appellation signifies the agreement of one term with another under a certain precision or restriction. This does not apply to other terms that produce real appellation.

Second, it is argued: A numerical term added to a substantive does not always number supposits by reason of forms; therefore the rule is false.

The antecedent is proved: If the divine Word assumed three human natures, they would not be called three human beings but one human being, as St. Thomas determines in Summa theologiae III, q. 3, a. 7. Yet several substantial forms would be numbered; therefore the rule is false.

This is confirmed: Conversely, if three persons assumed the same humanity, they would be called three human beings, and only one in a qualified sense, as St. Thomas says in the same place, a. 6. Therefore the substantive is now numbered not by reason of forms but by reason of supposits, even though they have one substantial form.

WE REPLY that in that case there would not be three human beings, because there would not be three supposits. The rule does not say that a substantive is pluralized when forms, but not supposits, are multiplied; it says that supposits are numbered by reason of forms, which is entirely true. But multiplying substantial forms does not suffice unless supposits are also multiplied, even though the forms themselves are the reason for the multiplication, because in that case the forms do not bring supposits with them and do not subsist in themselves in their connatural mode.

To the confirmation we reply that in that case St. Thomas says the three persons would be one human being in a qualified sense and simply several, as is clear in Summa theologiae III, q. 3, a. 6, ad 1: “For it could not be argued from the fact that the three persons are one human being that they are simply one; nothing prevents saying that human beings who are simply many are one in some respect, as one people.” Therefore, if three persons assumed one nature, they would simply be called three human beings. For them to be simply one, the unity of substantial form does not suffice when that form does not bring a supposit with it but comes to several supposits and has, as it were, the mode of a connotative term. Thus both plurality and unity in substantial forms are understood according to substantial forms existing in a substantial mode—that is, as bringing their subsistence and supposit with them—not as being drawn to an alien supposit or supposits and as it were taking on the laws and mode of connotative terms.

But why, YOU WILL ASK, are the three persons now simply called one God, and not several gods by reason of one nature, whereas in that case they would not be called one human being by reason of one human nature, but several human beings?

We reply that the difference consists in this: although the divine nature is in three persons, it is as perfect in the account of substantial form as if it were in only one person and brought its supposit with it. Therefore, with respect to the three persons, the divine nature does not take on the account of a connotative term, since it is not drawn to the persons as those who assume it and give being to the nature; rather, it has being of itself and thus exists simply and substantially, independently of the persons. Since unity follows being, if it has being perfectly of itself, it brings unity of itself. Human nature, by contrast, although substantially united to the persons, does not have in itself the whole perfection of substance or take on the mode of substantial form, but exists in a quasi-connotative way, receiving substantial being from the persons themselves. It is therefore not in a perfect state of giving substantial unity simply, independently of the persons, because it has being not of itself but from the persons. The divine nature, however, independently of the persons, is one God on account of the infinite perfection of such being and divine substance. See Cajetan, Summa theologiae III, q. 3, a. 6, at the end of the article.

The arguments that could be made against the rule of appellation of reason are the same as those brought forward in the preceding article when treating simple supposition. See them there.