Summa Theologica Part I (Prima Pars) Part 48

i, 1) it follows that a real relation in G.o.d can be based only on action. Such relations are not based on the actions of G.o.d according to any extrinsic procession, forasmuch as the relations of G.o.d to creatures are not real in Him (Q. 13, A. 7). Hence, it follows that real relations in G.o.d can be understood only in regard to those actions according to which there are internal, and not external, processions in G.o.d. These processions are two only, as above explained (Q. 27, A. 5), one derived from the action of the intellect, the procession of the Word; and the other from the action of the will, the procession of love. In respect of each of these processions two opposite relations arise; one of which is the relation of the person proceeding from the principle; the other is the relation of the principle Himself. The procession of the Word is called generation in the proper sense of the term, whereby it is applied to living things. Now the relation of the principle of generation in perfect living beings is called paternity; and the relation of the one proceeding from the principle is called filiation. But the procession of Love has no proper name of its own (Q. 27, A. 4); and so neither have the ensuing relations a proper name of their own. The relation of the principle of this procession is called spiration; and the relation of the person proceeding is called procession: although these two names belong to the processions or origins themselves, and not to the relations.

Reply Obj. 1: In those things in which there is a difference between the intellect and its object, and the will and its object, there can be a real relation, both of science to its object, and of the willer to the object willed. In G.o.d, however, the intellect and its object are one and the same; because by understanding Himself, G.o.d understands all other things; and the same applies to His will and the object that He wills. Hence it follows that in G.o.d these kinds of relations are not real; as neither is the relation of a thing to itself. Nevertheless, the relation to the word is a real relation; because the word is understood as proceeding by an intelligible action; and not as a thing understood. For when we understand a stone; that which the intellect conceives from the thing understood, is called the word.

Reply Obj. 2: Intelligible relations in ourselves are infinitely multiplied, because a man understands a stone by one act, and by another act understands that he understands the stone, and again by another, understands that he understands this; thus the acts of understanding are infinitely multiplied, and consequently also the relations understood. This does not apply to G.o.d, inasmuch as He understands all things by one act alone.

Reply Obj. 3: Ideal relations exist as understood by G.o.d. Hence it does not follow from their plurality that there are many relations in G.o.d; but that G.o.d knows these many relations.

Reply Obj. 4: Equality and similitude in G.o.d are not real relations; but are only logical relations (Q. 42, A. 3, ad 4).

Reply Obj. 5: The way from one term to another and conversely is the same; nevertheless the mutual relations are not the same. Hence, we cannot conclude that the relation of the father to the son is the same as that of the son to the father; but we could conclude this of something absolute, if there were such between them.

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QUESTION 29

THE DIVINE PERSONS (In Four Articles)

Having premised what have appeared necessary notions concerning the processions and the relations, we must now approach the subject of the persons.

First, we shall consider the persons absolutely, and then comparatively as regards each other. We must consider the persons absolutely first in common; and then singly.

The general consideration of the persons seemingly involves four points:

(1) The signification of this word "person";

(2) the number of the persons;

(3) what is involved in the number of persons, or is opposed thereto; as diversity, and similitude, and the like; and

(4) what belongs to our knowledge of the persons.

Four subjects of inquiry are comprised in the first point:

(1) The definition of "person."

(2) The comparison of person to essence, subsistence, and hypostasis.

(3) Whether the name of person is becoming to G.o.d?

(4) What does it signify in Him?

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FIRST ARTICLE [I, Q. 29, Art. 1]

The Definition of "Person"

Objection 1: It would seem that the definition of person given by Boethius (De Duab. Nat.) is insufficient--that is, "a person is an individual substance of a rational nature." For nothing singular can be subject to definition. But "person" signifies something singular.

Therefore person is improperly defined.

Obj. 2: Further, substance as placed above in the definition of person, is either first substance, or second substance. If it is the former, the word "individual" is superfluous, because first substance is individual substance; if it stands for second substance, the word "individual" is false, for there is contradiction of terms; since second substances are the genera or species. Therefore this definition is incorrect.

Obj. 3: Further, an intentional term must not be included in the definition of a thing. For to define a man as "a species of animal"

would not be a correct definition; since man is the name of a thing, and species is a name of an intention. Therefore, since person is the name of a thing (for it signifies a substance of a rational nature), the word "individual" which is an intentional name comes improperly into the definition.

Obj. 4: Further, "Nature is the principle of motion and rest, in those things in which it is essentially, and not accidentally," as Aristotle says (Phys. ii). But person exists in things immovable, as in G.o.d, and in the angels. Therefore the word "nature" ought not to enter into the definition of person, but the word should rather be "essence."

Obj. 5: Further, the separated soul is an individual substance of the rational nature; but it is not a person. Therefore person is not properly defined as above.

_I answer that,_ Although the universal and particular exist in every genus, nevertheless, in a certain special way, the individual belongs to the genus of substance. For substance is individualized by itself; whereas the accidents are individualized by the subject, which is the substance; since this particular whiteness is called "this," because it exists in this particular subject. And so it is reasonable that the individuals of the genus substance should have a special name of their own; for they are called "hypostases," or first substances.

Further still, in a more special and perfect way, the particular and the individual are found in the rational substances which have dominion over their own actions; and which are not only made to act, like others; but which can act of themselves; for actions belong to singulars. Therefore also the individuals of the rational nature have a special name even among other substances; and this name is "person."

Thus the term "individual substance" is placed in the definition of person, as signifying the singular in the genus of substance; and the term "rational nature" is added, as signifying the singular in rational substances.

Reply Obj. 1: Although this or that singular may not be definable, yet what belongs to the general idea of singularity can be defined; and so the Philosopher (De Praedic., cap. De substantia) gives a definition of first substance; and in this way Boethius defines person.

Reply Obj. 2: In the opinion of some, the term "substance" in the definition of person stands for first substance, which is the hypostasis; nor is the term "individual" superfluously added, forasmuch as by the name of hypostasis or first substance the idea of universality and of part is excluded. For we do not say that man in general is an hypostasis, nor that the hand is since it is only a part. But where "individual" is added, the idea of a.s.sumptibility is excluded from person; for the human nature in Christ is not a person, since it is a.s.sumed by a greater--that is, by the Word of G.o.d. It is, however, better to say that substance is here taken in a general sense, as divided into first and second, and when "individual" is added, it is restricted to first substance.

Reply Obj. 3: Substantial differences being unknown to us, or at least unnamed by us, it is sometimes necessary to use accidental differences in the place of substantial; as, for example, we may say that fire is a simple, hot, and dry body: for proper accidents are the effects of substantial forms, and make them known. Likewise, terms expressive of intention can be used in defining realities if used to signify things which are unnamed. And so the term "individual" is placed in the definition of person to signify the mode of subsistence which belongs to particular substances.

Reply Obj. 4: According to the Philosopher (Metaph. v, 5), the word "nature" was first used to signify the generation of living things, which is called nativity. And because this kind of generation comes from an intrinsic principle, this term is extended to signify the intrinsic principle of any kind of movement. In this sense he defines "nature" (Phys. ii, 3). And since this kind of principle is either formal or material, both matter and form are commonly called nature.

And as the essence of anything is completed by the form; so the essence of anything, signified by the definition, is commonly called nature. And here nature is taken in that sense. Hence Boethius says (De Duab. Nat.) that, "nature is the specific difference giving its form to each thing," for the specific difference completes the definition, and is derived from the special form of a thing. So in the definition of "person," which means the singular in a determined genus, it is more correct to use the term "nature" than "essence,"

because the latter is taken from being, which is most common.

Reply Obj. 5: The soul is a part of the human species; and so, although it may exist in a separate state, yet since it ever retains its nature of unibility, it cannot be called an individual substance, which is the hypostasis or first substance, as neither can the hand nor any other part of man; thus neither the definition nor the name of person belongs to it.

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SECOND ARTICLE [I, Q. 29, Art. 2]

Whether "Person" Is the Same As Hypostasis, Subsistence, and Essence?

Objection 1: It would seem that "person" is the same as "hypostasis,"

"subsistence," and "essence." For Boethius says (De Duab. Nat.) that "the Greeks called the individual substance of the rational nature by the name hypostasis." But this with us signifies "person." Therefore "person" is altogether the same as "hypostasis."

Obj. 2: Further, as we say there are three persons in G.o.d, so we say there are three subsistences in G.o.d; which implies that "person" and "subsistence" have the same meaning. Therefore "person" and "subsistence" mean the same.

Obj. 3: Further, Boethius says (Com. Praed.) that the Greek _ousia,_ which means essence, signifies a being composed of matter and form.

Now that which is composed of matter and form is the individual substance called "hypostasis" and "person." Therefore all the aforesaid names seem to have the same meaning.

Obj. 4: _On the contrary,_ Boethius says (De Duab. Nat.) that genera and species only subsist; whereas individuals are not only subsistent, but also substand. But subsistences are so called from subsisting, as substance or hypostasis is so called from substanding.

Therefore, since genera and species are not hypostases or persons, these are not the same as subsistences.

Obj. 5: Further, Boethius says (Com. Praed.) that matter is called hypostasis, and form is called _ousiosis_--that is, subsistence. But neither form nor matter can be called person. Therefore person differs from the others.

_I answer that,_ According to the Philosopher (Metaph. v), substance is twofold. In one sense it means the quiddity of a thing, signified by its definition, and thus we say that the definition means the substance of a thing; in which sense substance is called by the Greeks _ousia,_ what we may call "essence." In another sense substance means a subject or _suppositum,_ which subsists in the genus of substance. To this, taken in a general sense, can be applied a name expressive of an intention; and thus it is called _suppositum._ It is also called by three names signifying a reality--that is, "a thing of nature," "subsistence," and "hypostasis," according to a threefold consideration of the substance thus named. For, as it exists in itself and not in another, it is called "subsistence"; as we say that those things subsist which exist in themselves, and not in another. As it underlies some common nature, it is called "a thing of nature"; as, for instance, this particular man is a human natural thing. As it underlies the accidents, it is called "hypostasis," or "substance." What these three names signify in common to the whole genus of substances, this name "person" signifies in the genus of rational substances.

Reply Obj. 1: Among the Greeks the term "hypostasis," taken in the strict interpretation of the word, signifies any individual of the genus substance; but in the usual way of speaking, it means the individual of the rational nature, by reason of the excellence of that nature.

Reply Obj. 2: As we say "three persons" plurally in G.o.d, and "three subsistences," so the Greeks say "three hypostases." But because the word "substance," which, properly speaking, corresponds in meaning to "hypostasis," is used among us in an equivocal sense, since it sometimes means essence, and sometimes means hypostasis, in order to avoid any occasion of error, it was thought preferable to use "subsistence" for hypostasis, rather than "substance."