Cursus Philosophicus Thomisticus, Secunda Pars Artis Logicae

FOUR things are to be noted in this article: First, what predication is, taken formally and fundamentally; second, what is required for the verification of predication; third, how a higher predicate must be a whole in relation to a lower one in order to be predicated of it; fourth, how many kinds of predication there are.

Concerning the first, it should be noted that predication pertains to the second operation, in which one thing is enunciated of another; thus predication is the attribution of one thing to another by denying or affirming. Hence St. Thomas says in chapter 4 of On Being and Essence, at the end,¹ that “predication is something completed through the action of the intellect composing and dividing, yet having in the thing as its foundation the very unity of those things, one of which is said of the other.” There he explains the formal character of predication, which is the attribution itself, or the joining of the extremes in the manner of attribution; but joining is a relation. The foundation of this relation or attribution is the identity or agreement of the extremes, if the predication is affirmative, or their disagreement, if it is negative.

St. Thomas explains this more fully in 1. p. q. 13. art. 12., where he shows that in every affirmative proposition it is required that subject and predicate signify something that is in some way the same in reality and diverse in account. This is clear in both accidental and substantial predications. For example, when I say “A man is white,” it is evident that they are the same in subject but differ in account, because the account of white is one thing and that of man another. Likewise, when I say “A man is an animal,” the very thing that is a man is truly an animal. Thus predicate and subject are the same in supposit but diverse in account. Therefore, the intellect identifies the identity of the extremes through the very composition and copula, and their diversity through the distinct concepts of predicate and subject.

The same doctrine is drawn from On Interpretation 1, lect. 3². Thus it is clear what predication is and on what it is founded. How the identity of the extremes differs from an intrinsic or extrinsic connection will be said below, in treating the fourth point.

Concerning the second: The verification of predication is founded on the identity and agreement of the extremes in such a way that this must be considered not only on the part of the thing signified but also on the part of the mode of signifying. For the intellect, since it is naturally disposed to compose things that are separate and divide things that are united, sometimes apprehends and signifies one and the same thing in such a way that, from the mode of signifying itself, it cannot be applied or united to another; at other times it conceives it in such a way that it can be applied and united. Hence St. Thomas, in 1. p. q. 39. art. 4. and 5., warns that in the properties of expressions and their truth one must consider not only the things signified but also the mode of signifying. This mode is especially evident in whether something is signified abstractly or concretely, in the manner of a whole or a part. Since every whole is greater than its part, a part and a whole cannot be equally matched and attributed. Hence St. Thomas, in opusculum 69, on the second text of Boethius³, says: “What is considered abstractly has this truth: that it does not have within itself anything extraneous, namely, anything beyond its essence, as humanity and whiteness and whatever is said in this way. The reason is that humanity is signified as that by which something is a man, and whiteness as that by which something is white. For, formally speaking, something is a man only through that which pertains to the account of man. Likewise, something is formally white only through that which pertains to the account of white. Therefore, abstracts of this sort cannot have anything alien within themselves. But it is otherwise with things signified concretely. For man is signified as one who has humanity, and white as that which has whiteness. But from the fact that a man has humanity or whiteness, he is not prevented from having something else that does not pertain to the account of these, except only what is opposed to them. Therefore man and white can have something other than humanity or whiteness. This is why whiteness or humanity is signified in the manner of a part and is not predicated of concrete things, just as neither is a part predicated of its whole.” So St. Thomas.

From this doctrine you may gather that an abstract term in relation to a concrete one abstracts by formal abstraction, not total abstraction. Formal abstraction is that by which form is abstracted from matter, act from potency, and what is essential and proper from what is extraneous and alien. Total abstraction, however, is that by which a higher term is abstracted from a lower one and the common from individuals, because it is related as a whole to the lower, virtually and implicitly including them. A formal abstract, however, is not related as a whole to a concrete term, but as a part and, as it were, form and act in relation to potency and subject.

Second, it follows how the commonly stated claim is true: when something belongs to a thing per se, its opposite cannot belong to it even accidentally, that is, it cannot be found in the same subject. For, as St. Thomas says, a subject having some form is not prevented from having anything else except only what is opposed to that form. Therefore the opposite of a form cannot be found in the very subject that has the form; that is, it cannot belong to it even accidentally, through something else and by reason of the subject.

Concerning the third point, namely, how such a higher predicate is a whole in relation to a lower one: its explanation is taken from St. Thomas in the place cited above and in chapter 3 of On Being and Essence⁴, and from Cajetan's explanation there of how genus has the character both of a part and of a whole. For a generic predicate (and the same applies to a specific or differential predicate) contains both something it explains and something it implies or includes. For example, “animal” expresses sensitive nature, and “body” expresses corporeal nature; that is, each expresses what actually constitutes the sensitive or corporeal. But it includes everything from which such a character of sensitive or corporeal can proceed, or in which it can be found, whether or not it includes something beyond the account of sensitive. As regards what it expresses, there is no doubt that a genus, for example animal, states only a part of the nature and not the whole. Hence, if the word “animal” included nothing more than what it explains, it could not be predicated of anything in which something more than the very account of sensitive nature is found. But because it signifies every form from which the character of animal proceeds, and in which it is found, whether only that character or something else proceeds from such a form, it follows that “animal” in that concept virtually includes whatever has the character of animal, and “man” whatever has the character of man.

From this doctrine it is gathered that, for something to be a genus and universal, it must signify its signified object not with formal precision but only with total precision. That is, it must not signify some account or form in such a way as to exclude what can be joined or connected with it; rather, it signifies everything in which such a perfection is found, even if it involves a further perfection without explaining it. Thus being signified in the manner of a whole or of a part is not the same as being a part or a whole. For even what is a part can be signified in the manner of a whole in relation to another part in which it is included, as animality is in relation to humanity, since it is predicated of it. To be signified in the manner of a whole consists in signifying something in relation to another as including it. Something is signified in the manner of a part when it signifies something by way of exclusion, although in reality it is joined to what it excludes. And because in reality no nature or form is given that constitutes some grade while excluding a further perfection or grade, but several grades proceed from the same substantial form, we said above, following St. Thomas, that metaphysical grades in the same thing are distinguished only in account.

Concerning the fourth point: There are many divisions and differences of predication, resulting from the diverse ways of having identity and diversity of account, in which, as we said following St. Thomas, the whole foundation of predication lies.

FIRST, it is divided into direct and indirect. Direct predication occurs when that which functions in the manner of a form is placed on the side of the predicate; indirect predication occurs, conversely, when that which functions in the manner of a subject is placed on the side of the predicate. By “subject” and “form” we understand not only what is physically related as form and matter, but whatever in any way functions as actualizing and actualizable, or as higher and lower. For the higher is called the form of the lower, not because the higher grade is more actual in being and perfection, but because it is contractible; and everything that is contracted is, as it were, received in that to which it is contracted. If the predicates are equal, as “man” and “rational” or “capable of laughter,” then what actualizes functions as form and what is actualized as subject. Hence this is direct predication: “A man is rational,” “a man is capable of laughter”; indirect predication is “The rational is a man.”

If you ask whether predication is direct when a higher grade is individuated as predicate, as when you say “A man is this animal,” the answer is that, for predication to be direct, the individuated genus must be placed on the side of the subject. Thus, if you say “This animal is a man,” the words “this animal” point out an individual man, or that animal which is in a man. For precisely because the higher grade is individuated through a mode of signifying it individually, it functions as a recipient of the very account of the species, since it stands for the animal that is an individual of man. Therefore it regards man as higher and consequently as a formal predicate. Thus “This animal is a man” is direct predication, whereas “A man is this animal” is indirect. The case is different if you say “A man is a certain animal,” provided “a certain” does not point out an individual, but the generic account of animal as vaguely contracted.

DIRECT PREDICATION is divided into essential and accidental. Essential predication occurs when the predicate belongs to the intrinsic account of the subject; accidental predication occurs when it lies outside that account. Here one must distinguish the identity of the extremes from their connection. Identity pertains to the union, agreement, and adequation of the extremes, which every predication requires; connection pertains to the relation by which the extremes are ordered either essentially and intrinsically or accidentally and extrinsically.

DISPARATE PREDICATION is that which consists of terms that are disparate in their relation and have no relation of agreement with one another. Note carefully that disparate or identical predication is one thing, and a disparate or identical proposition another. A proposition regards truth and falsity; predication regards the relation of the terms. A predication can be disparate while the proposition is true, and a proposition between identical terms can be false, as is clear in negatives: “A man is not a stone” is a true proposition and a disparate predication; the proposition “A man is not a man” is false, but its predication is identical, that is, between identical terms, although negative. In affirmative propositions, however, if the predication is disparate, it is always false; and if the predication is identical, the proposition is true.

IDENTICAL PREDICATION is either materially identical or formally identical. It is formally identical when, by the force of the terms' signification, one signifies the same as the other, as when it is said “A man is a man.” It is materially identical when the significations are indeed diverse, but the reality or entity is the same, as when it is said “Action is passion” or “The white is substance or body.” These are disparate on the part of the form signified, but identical on the part of the matter or subject, which is body or substance, if they agree in the same subject. Likewise, when two accidents are predicated by reason of their agreement in the same subject, as “The white is sweet,” and when one attribute is predicated of another in God, as “Mercy is justice,” all these predications are materially identical.