Cursus Philosophicus Thomisticus, Prima Pars Artis Logicae

Concerning simple supposition, whose definition we gave in the text,¹ there is usually a difficulty about how it is distinguished from the other suppositions, and first from natural supposition. For it seems that simple supposition also signifies a necessary connection and relation between terms. When I say, “A human being is a species,” it is simple supposition because it gives this sense: “A human being conceived by a proper or common concept is a species.” But the predicate “species” belongs essentially to the common concept of human being; therefore it signifies an essential connection of the terms. Another difficulty is that the definition of simple supposition also seems to fit natural supposition, as when a definition is predicated of what is defined, for example, “A human being is a rational animal.” The term “human being” is taken for its immediate signification, which it signifies per se and formally in that way. For it is human being, not Peter or Paul as an individual, that is defined. Therefore the definition of simple supposition also fits natural supposition, in which a definition is predicated of what is defined.

A second difficulty is whether simple supposition can be found in a singular term, as when I say, “Peter is an individual.” A singular term does not seem to have an immediate signification distinct from a mediate one, by reason of which it could supposit simply; rather, it has only one adequate signification for which it supposits singularly. On the other hand, just as in the term “human being,” when a term of second intention is predicated of it, simple supposition occurs because it does not pass to mediated significations (for “A human being is a species; therefore Peter is a species” does not follow), so likewise, when a predicate of second intention is predicated that belongs not to nature in common but only to an individual, it also supposits simply. Thus this also does not follow: “Peter is an individual and is not predicable of many; therefore a human being is an individual and is not predicable of many.”

Finally, in propositions whose subject is incompatible with a predicate of second intention, as “Peter is a species” or “A human being is an individual,” the subject ought to supposit simply, since the predicate is a term of second intention and does not pass to mediated significations. Yet the subject is not taken for what it first and per se signifies, since the concept of the predicate is incompatible with the concept of the subject and consequently does not appeal to that subject’s own proper and per se concept. Therefore, and so on.

A BRIEF ANSWER TO THESE DIFFICULTIES begins by distinguishing simple supposition from material and personal supposition. It differs from material supposition because simple supposition is for the thing itself signified, not for the name signifying it; it differs from personal supposition because it supposits only for the immediate signification and in no way for the mediate one. We should keep in view St. Thomas’s teaching in De potentia, q. 9, a. 4,² that a name signifies in two ways: one way formally, another materially. The formal signification is that for the signifying of which a name was imposed principally; the material signification is that in which the account signified by the name is preserved and found. Thus the name “human being” signifies human nature, but that nature is preserved in an individual. For there to be simple supposition, then, the term must supposit for one signification, namely, the immediate one, in such a way that it cannot pass or descend to the mediate one; for if it can pass to both, it does not remain simple but is, as it were, a twofold supposition, corresponding to two significations. This occurs only with predicates of second intention in relation to their subject or foundation. For if the predicates are real, they can for that very reason be found on the side of the thing and consequently in some individual, not only in the nature. Therefore it does not suffice for simple supposition that a predicate belong to the immediate signification of a name; it must belong to that signification with some precision that excludes the other.

To the first difficulty, then, we reply that the proposition is in no way essential. For propositions to be essential, the necessary connection and relation must be signified by the force of the terms themselves, not by the force of some application or state in which a term is clothed or applied, unless that application or state is expressed in the proposition. In that case the term expressing the state can signify a necessary connection with the predicate, as in “A white human being disperses sight.” Although the subject is verified of a white human being and supposits for one, the term “human being” itself does not signify the whiteness, which is what essentially belongs to dispersing sight; therefore this proposition is not essential. But “A white human being disperses sight” is essential. Likewise, if you say, “A human being is a species,” although it is verified of a human being conceived in common, the proposition is not essential, because the term “human being” itself does not explain that it is conceived in common. But if the proposition says “a human being conceived by a common concept,” then “is a species” is predicated essentially of it; it gives this sense: “A human being, insofar as it is a species, is a species.”

To the objection on the other side we say that although a definition belongs to a term by reason of its nature and quiddity, it is not simple supposition, because the definition does not belong to the nature, its immediate signification, in such a way that it could not also belong to the person or individual in which that nature is found. Indeed, just as quiddity and nature descend to individuals, so too does the definition. Although when a human being is defined it is not Peter who is defined immediately and according to individuation, Peter is defined mediately according to his nature and quiddity.

To the second difficulty we reply that simple supposition can also be found in a singular term, since it has an immediate and a mediate signification, but in the inverse order from a common term. In a common term, the immediate signification is the nature, and the mediate signification is the person to whom that nature belongs. In singular terms, however, the immediate signification is the person or individual, and the mediate signification is the nature of which that person is constituted. Thus a person is defined as “an individual substance of a rational nature.” The immediate and direct signification is substance, or the individual supposit; the mediate or indirect signification is nature. Therefore all predicates that signify the second intention of singularity produce simple, not personal, supposition in a singular term. For example, when it is said of Peter that he is a lower thing subordinated to an atomic species, predicable of one and not of many, an individual, and so on, the consequence from a singular term to a common term is valid, as the argument says.

To the third difficulty we reply that either position can be maintained in those propositions: the subject supposits either simply or personally.

The first view is explained as follows: By the very fact that the subject is joined by the copula to a term of second intention according to the requirement of that copula, it makes, as it were, an appeal to stand under the account of its own immediate and proper concept. Although the predicate is incompatible with the subject, this proves only that it does not belong to it and thus makes the proposition false; it does not prove that the subject fails to supposit according to the requirement of that copula and predicate. The proposition “Peter, as conceived by a proper concept, is a species” therefore has this sense and is false. Likewise, in “A human being is a stone,” the term “human being” supposits: although the predicate does not belong to it, a human being can nevertheless be found and pointed out according to the requirement of the verb “is.” Otherwise it is not clear what supposition the subject “Peter is a species” has, if it does not supposit simply, since personal supposition does not fit with respect to that predicate of second intention.

The second view is explained by saying that the subject can supposit personally. Although the predicate is of second intention, it is not signified to belong to the subject but to be incompatible with it; it is incompatible with the subject even on the side of the thing. Therefore, when a predicate of second intention is incompatible with the subject, it need not make that subject supposit simply, since it is incompatible with the subject even under personal supposition and in its mediate signification, which is on the side of the thing.

Concerning the other species and divisions of supposition, their rules, both for absolute and relative terms, many sophisms and consequences are usually multiplied. If they were treated here in detail, this work would grow without limit. We therefore omit them for now and shall indicate the principal points in the next question, article 3.

At present we should note concerning alienation whether propositions in which the subject is alienated from the predicate are in a contingent, remote, or necessary matter, as when I say, “A human being is painted,” or “A human being is dead.” For if the subjects are alienated, they do not supposit for a real human being, but for a painted or dead human being, of whom it is said essentially that he is dead or painted.

WE REPLY that the predicate “painted” or “dead” can be taken in two ways: participially, or with the force of a verb, and nominally, or with the force of a noun. Taken participially, the proposition “A human being is dead” is verified through the ampliation of the subject to a real human being, not through alienation. For by ampliation we say of a real human being that he is dead, that is, has died or ceased to exist; this is said of a real human being because it gives this sense: “The human being who existed before no longer exists, but has ceased to exist.” Likewise, if one says, “A human being is painted,” taken participially it gives this sense: “A real human being is depicted in a painting, whether or not that human being now exists.” In this sense these propositions are in contingent matter, because the predicates are accidents of their objects. Although they are present with the corruption of the subject, this does not involve corruption of the essential concept, but only of existence, which does not remove accidental predication, as will be said in the chapter on Accident in the Predicables.³ If, however, the proposition is considered without ampliation, precisely according to the force of its terms, it is in remote matter, since the terms “human being” and “dead,” or “human being” and “painted,” are incompatible: something cannot be a human being and dead. But if “dead” is taken nominally, it makes an alienation of the subject; for “dead human being” means the same as “corpse of a human being,” and “painted human being” means “painting of a human being.” It is clear that the predicate is verified necessarily of a subject alienated in this way, because the alienation leaves the term, as it were, in an alien signification—that is, as a human corpse or a painting of a human being—of which “dead” and “painted” are said essentially. In that case, therefore, the proposition is in natural matter.