Cursus Philosophicus Thomisticus, Prima Pars Artis Logicae

Aristotle defines the verb as “a vocal sound significant by convention, with time, no part of which signifies separately, finite and in the nominative case, and always a sign of things predicated.” So Aristotle in On Interpretation I¹ and St. Thomas there, lecture 5². The first three clauses, namely “vocal sound significant” and “by convention,” have been explained in the definition of the term.

The clause “with time,” included to distinguish it from the name, signifies nothing other than signifying a thing in the manner of motion, or of action and passion, since motion is measured by time. To signify with time is not to signify time itself as a thing—for that is done by the name³—but to signify a thing as measured by time. A thing is measured by time when it is signified as flowing according to some motion or action, for motion and action are measured by time primarily and in themselves. Hence, when the verb is absolved from time, as when I say “Man is an animal,” and in other propositions of eternal truth, the verb does not cease to signify with time, that is, in the manner of action or flow; rather, it ceases to restrict the truth of the proposition so that it depends on time. That is, the extremes are joined not solely by reason of time and dependently on something temporal, but through their intrinsic quiddity, although this very thing is signified in the manner of time and action. On this, see below, question 3, article 1.

The fifth clause, “no part of which signifies separately,” is included to distinguish the verb from an expression and to exclude complex verbs, which are not one verb but several, as we said of the name. Neither an adjectival verb nor a substantive verb is subordinated to a double concept, such that it signifies a thing in order to signify action or motion as a mode of union or composition. For these are not two significations or two concepts, but one signified thing with a certain mode of signifying. Likewise, a name signifies a thing in the manner of what subsists in itself; the thing and the mode of subsisting in itself are not two significations, because no thing is signified without some mode. The verb “is” itself, whether it is “of second adjunct,” as when I say “Peter is,” or “of third adjunct,” as when I say “Peter is white,” adding a third word as predicate, always signifies the same thing, namely, being. For, as St. Thomas says, On Interpretation I, lecture 5, at the end⁴, this actuality is common to every form, whether substantial or accidental. Hence, when we wish to signify that any form inheres in something, we signify it by the verb “is”; consequently, it signifies composition. So St. Thomas.

The sixth clause, “finite,” excludes the infinite verb, as in “does not walk,” for the same reason that infinite names were excluded from the account of a name. A negated verb is distinguished from an infinitized verb: the negated verb corresponds to a complex concept, namely, the verb itself and the particle “not”; the infinitized verb, however, corresponds to a single concept, as we said of the name. A negated verb makes a negative proposition, but an infinitized verb does not. If a verb placed within a proposition is infinitized, this is not with respect to the copula and the union of the extremes (for this is never infinitized by negation, but is negated and thereby makes a negative proposition); rather, it is infinitized only with respect to the thing signified, as will be said below, question 3, article 2.

The seventh clause, “straight,” is included to exclude oblique verbs. Just as in the case of the name, that is called oblique which declines and falls away from the proper mode of a name, which is to signify in the manner of a “what” and of something subsisting in itself, while the oblique is signified as belonging to another; so in the case of the verb, that is called oblique which falls away from the proper mode of the verb, which is to signify with motion and action—namely, when it signifies an action in the past or future, and so on. For this is not action simply, but only what is present; hence, through the declension of tenses, the verb becomes oblique.

The final clause, “and always a sign of things predicated,” is included by Aristotle and St. Thomas, and therefore we include it, although others omit it. It is included to exclude the participle, which can indeed be placed on the side of either predicate or subject, although it signifies with time. Nevertheless, it is excluded from the account of the verb because the verb always belongs on the side of the predicate: it either signifies the predicate itself or is required to join the predicate to the subject. Therefore it is a sign—that is, a sign of things said, namely, things predicated—because it composes and joins them to the subject, as was said. If it is ever placed on the side of the subject, as with a verb in the infinitive mood, this is because the verb is then taken with the force of a name, not in the manner of a verb. So St. Thomas, On Interpretation I, lecture 5⁵.