Cursus Philosophicus Thomisticus, Secunda Pars Artis Logicae

The common understanding and conception of everyone is that by the name “universal” we understand something that bears some relation to many things. It is set against the singular, which cannot be communicated to many. But because something can stand in relation to many things and be disposed toward them in several ways, “universal” can likewise be taken in several senses. All its senses are reduced to three: a universal in signifying, a universal in causing, and a universal in being or predicating.

A universal in signifying is a sign that signifies the universal itself, or can be applied universally to many things. Such are common names or terms, which signify a thing in common and can be applied to many things, as “human being” and “animal.”

A universal in causing is that whose power extends to many effects, whether it is an efficient cause or a cause in another genus, as the heavens or God. Note that causal universality bears upon its effects in such a way that it reaches in them not only universal and common accounts or predicates, but also particular ones. Indeed, the more universal a power is in causing, the more deeply it penetrates its effect and reaches and causes all the particular accounts of that effect, since all of them participate in that common account; thus a power that can act upon that whole account can consequently act upon all the things that participate in it. For example, the heavens, which are the universal cause of these bodies, reach every corporeal account down to individual differences; and God, who is the most universal cause of being insofar as it is being, causes every account that in any way participates in entity. This principle serves many theological difficulties, especially for understanding how, on the part of an inferior cause, nothing is presupposed for acting—whether as to the substance of the work or its mode—that is not anticipated by the superior cause, insofar as it is participated in and descends from that cause.

Finally, a universal in being or predicating is that which bears upon many things, in which it has being and of which it is predicated, as animal is found in all animals and human being in all human beings. A universal taken in this last sense is defined as “one in many and of many.” Or, as Aristotle defines it in Metaphysics VII, ch. 13¹: “A universal is what is naturally apt to be in many.” There St. Thomas notes, lect. 13², that the Philosopher did not say that a universal is what is in many, but what is apt to be in many, because there are many universals that in fact exist only in one singular thing, such as the sun and the moon.

That first definition explains everything that contributes to the account of a universal: namely, its subject, foundation, relation to its term, and proper attribute. The subject and foundation are explained by the word “one,” for it refers to a thing that is one; and it explains unity as separated from many things and communicable to them. The Philosopher's definition expresses this communicability more explicitly, saying “what is apt to be in” many. Unity separated from many and aptitude to be in them are the foundation of the universal relation, just as the power to generate is the foundation of the relation of fatherhood. The relation itself, in which formal universality consists, is explained by its order to its term, namely, “in many”; for these are related as inferiors, which the universal directly regards. It is said to be in many by identity with them, because through communication and contraction to inferiors the universal becomes the same as the singular or inferior. It is said to be “of many” by predication: nothing, however, is predicated of another unless it is the same as it, not different; this explains predicability, which is the attribute of universality.

From what has been said, two things follow. FIRST, we see how to explain the distinction between the two kinds of universal, one physical, the other logical. The metaphysician considers natures chiefly, whereas the logician considers intentions or relations of reason. The nature itself, or the subject abstracted from many things, is therefore called a metaphysical universal, because nature is considered in it directly and chiefly, while abstraction or universality is considered as a condition. Universality itself is a condition required for every science, since no science treats of singulars. A logical universal, by contrast, chiefly regards the intention or form by which something is denominated universal; this is a second intention and a relation of reason. The logician considers this especially, while presupposing nature as that in which universality is founded: for the logician treats of second intentions as founded in first intentions. Thus we understand that the metaphysician and logician treat of the same thing in different ways, as is said in Metaphysics IV, lect. 4³ according to St. Thomas: the metaphysician treats chiefly of nature, the logician of intention.

SECOND, it follows that universality and particularity belong to the account of the state of nature itself, which can be denominated universal or singular. Hence three states are usually assigned to any nature, as is clear from St. Thomas's teaching in ch. 4 of On Being and Essence and Cajetan's commentary there.⁴

The first is the state of nature considered in itself, since in it only those things are considered that constitute the nature and quiddity itself. It is therefore also called the state of indifference, because nature in itself is indifferent to accidental predicates.⁵ It is also called the state of solitude, because nature stands alone, apart from every extrinsic predicate. It is also called “common” negatively, because nature is not understood as multiplied.

The second state is the being that nature has in singular things; this is the state of singularity.

The third, finally, is the being that nature has in the intellect's abstraction. This abstraction may also be called a state of solitude, not in the sense of solitude from every extrinsic predicate, but only of solitude or separation from individuals. Neither of these two states belongs to nature considered in itself, because neither is an essential predicate of nature. For if nature in itself were universal, it could never be singular; and if it were singular in itself, it could never be found as universal. Therefore, in the state of nature considered in itself, every predicate that is not quidditative is denied of it. This is why what appear to be extremes that are contradictory are denied of nature in that first state when the phrase “in itself” is added. For we say that nature in itself is neither one nor many, neither white nor not white; that is, it is not essentially one, not essentially many, but is capable of either. Do not infer from this, however, that two contradictories are verified of nature considered in itself. That is never possible: one is always true and the other false. If you say, “Human being in itself is not white” and “Human being in itself is white,” the second is false and the first true, because the sense is “Human being is not essentially white,” which is true, and “Human being is essentially white,” which is false. Thus this inference is invalid: “In itself, it is not white; therefore, in itself, it is nonwhite,” because the supposition changes on account of the phrase “in itself.”