Summa summae S. Thomae sive compendium theologiae

Person is rightly defined by Boethius, in the book On the Two Natures: "An individual substance of a rational nature." This definition Saint Thomas explains and defends here and elsewhere, and with him theologians commonly.¹

Whence you will infer that hypostasis and subsistence extend more broadly than person;² for what hypostasis and subsistence signify in the whole genus of substances, this name "person" signifies in the genus of rational substances.

The question here is one of no small difficulty: by what the divine persons are constituted. For its resolution.

Note 1° that relation involves a twofold concept, namely the concept of being in and the concept of being toward. The concept of being in is common to all accidents, and in the divine, to all relations, with this difference: that in created relations it implies inherence, since it is an accident; in the divine, subsistence, since it is substance, that is, identified with the divine nature; whence the foundation of the divine relation, insofar as it is real, is not something real and distinct, as in creatures, but the very identification with the divine nature. The concept of being toward is specific to relation, and by it relation is distinguished from other accidents, and diverse relations are disjoined from one another, insofar as they express a respect toward diverse terms.

Note 2° with Cajetan, whom John of St. Thomas and several other Thomists follow, that within the very concept of being toward a twofold concept, or twofold aspect, can again be distinguished: the first, insofar as it is a relative entity in itself, or in the signified act, and affecting the subject as that by which it is such; the second, insofar as it itself, in exercised act, actually refers as that which to the term. For it is prior to conceive the relation in itself, entitatively affecting the subject as that by which, than to conceive it as actually referring to the term: just as it is prior to conceive whiteness entitatively and in signified act as affecting the wall as that by which it is white, than to conceive it as actually rendering it white, although they occur at once and simultaneously in time.

Nor should you say that this concept of being toward, affecting the subject as that by which, or in signified act, coincides with the concept of being in. For the concept of being in pertains not only to the line of relative being, but also of absolute being, since it implies not only the inherence or subsistence of the toward itself, but also the intrinsic and absolute predicates of created or uncreated being: such that, if it be a created and accidental relation, it implies not only inherence, but also the character of a limited, dependent, potential being, etc., and all the perfections and imperfections of such an accident; if it be an uncreated relation, the concept of being in implies not only subsistent and real being, but also the very divine entity with all the attributes and perfections which are included in the word divine.

I say: The divine persons are constituted by relations, not under the concept of a form referring in exercised act, but under the concept of an entity or form affecting the subject and hypostatically subsisting.³

Proof by argument, by which various opinions are at the same time refuted. The divine persons are constituted by something real. But that real thing in the divine cannot be other than relation. Therefore.

The major premise is established. For the divine persons are real and are really distinguished from one another independently of the intellect; and that by which they are, and by which they are distinguished, is that by which they are constituted.

Proof of the minor. Every real thing that we can conceive in the divine persons is either the persons themselves considered entirely in themselves, or something absolute common to all, or something notional proper to each,⁴ and this notional element is threefold, namely origin, innascibility with respect to the person of the Father — concerning which the difficulty is greatest — and relation. But of all these grounds, none except relation can constitute a divine person. Therefore.

Each of the minor's parts must be proved.

Proof of the first part of the minor, against Praepositivus⁵ and Gregory of Rimini. That by which the divine persons are constituted in the character of such a person is that by which they are distinguished from one another. But the divine persons are not distinguished from one another in their entirety, otherwise they would differ by essence and in essence — in which, however, they agree. Therefore. Hence in the Fourth Lateran Council, Book I of the Decretals, chapter Firmiter, it is said: "The most holy Trinity is undivided according to the common essence, but distinct according to the personal properties." And in the Council of Florence, session 1, it is asserted that "the divine persons differ by their properties." Whence this opinion of Praepositivus, which Saint Thomas mentions below, q. 32, a. 2, o., is commonly rejected by theologians and marked with various censures.

Proof of the second part of the minor. What is common to the three persons cannot constitute a particular person distinct from the others. But all absolute things in God are common to the three persons, as all theologians admit. Therefore. Whence this opinion, which is attributed to John of Ripa, Lychetus, and a few of the ancients, has already been banished from the schools, as at least erroneous and rash.

Proof of the third part of the minor, and first, that the person of the Father is not constituted by innascibility, against Vasquez and Alarcón: because innascibility is taken either formally or fundamentally. If formally, then it posits nothing,⁶ but expresses only the negation of a principle; but the person of the Father is real and is constituted by something real. If it is taken fundamentally, that is, as the foundation of such a negation, then either that foundation is absolute, and thus incapable of constituting a person, as we have said, or it is relative, which can be nothing other than the relation of paternity.

Proof again of the third part of the minor, namely that the persons are not constituted by active and passive origins,⁷ which opinion is commonly attributed to Saint Bonaventure.

Against the notion of origin is that it should constitute a person. Therefore. — Proof of the antecedent, first: Person implies, from its essential concept, a fixed and permanent being, and being in the state of accomplished fact, since it is the ultimate term of nature, rendering it incommunicably subsistent. But origin is conceived essentially as being in the process of becoming: namely, active origin, as an influx and egress from a principle; passive origin, as a way and a tending toward a term. Therefore. — Proof, second, of the same antecedent: Active origin presupposes the person from whom it proceeds; for actions belong to supposits, and it is prior for the person to be than for the person to act. Therefore it does not constitute it. Passive origin, moreover, is presupposed for the constitution of the person, since it is the way toward constituting it; whence it cannot be said to constitute it formally, but only by way of process and causally: just as Peter is constituted formally a man by humanity, but only by way of process and causally by nativity: but the question here concerns the formal constitutive. Therefore.

It remains, then, that relation alone is the constitutive of the divine persons, because it alone is that by which they are distinguished from one another; and it alone distinguishes, because it alone brings opposition and incommunicability, for all absolute things are common to the three persons. Whence that celebrated saying of Boethius: "Substance affords unity, relation multiplies the Trinity," and that well-known saying of Anselm: "All things in the divine are one and the same, where the opposition of relation does not stand in the way." And in the Second Council of Toledo, in the confession of faith, it is thus stated: "In the relation of the persons, number is discerned." And below: "By this alone do they suggest number, that they are toward one another."

By relation, I say, the persons are constituted: not indeed by relation in exercised act, or conceived as a form actually and in exercised act regarding, or as it were looking toward, the term as that which, for taken thus it presupposes the person and follows upon generation; but by relation conceived in signified act as that by which, according to quiddity, insofar as it affects the subject, and indeed substantially, as being identified with the divine nature, under which concept it has the character of a hypostatic and subsisting form. Note these things carefully for the solution of difficult objections.