Summa Theologica, Part I

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 God, 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 assumptibility is excluded from person; for the human nature in Christ is not a person, since it is assumed by a greater--that is, by the Word of God. 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. _______________________

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 God, so we say there are three subsistences in God; 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 God, 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."

Reply Obj. 3: Strictly speaking, the essence is what is expressed by the definition. Now, the definition comprises the principles of the species, but not the individual principles. Hence in things composed of matter and form, the essence signifies not only the form, nor only the matter, but what is composed of matter and the common form, as the principles of the species. But what is composed of this matter and this form has the nature of hypostasis and person. For soul, flesh, and bone belong to the nature of man; whereas this soul, this flesh and this bone belong to the nature of this man. Therefore hypostasis and person add the individual principles to the idea of essence; nor are these identified with the essence in things composed of matter and form, as we said above when treating of divine simplicity (Q. 3, A. 3).

Reply Obj. 4: Boethius says that genera and species subsist, inasmuch as it belongs to some individual things to subsist, from the fact that they belong to genera and species comprised in the predicament of substance, but not because the species and genera themselves subsist; except in the opinion of Plato, who asserted that the species of things subsisted separately from singular things. To substand, however, belongs to the same individual things in relation to the accidents, which are outside the essence of genera and species.

Reply Obj. 5: The individual composed of matter and form substands in relation to accident from the very nature of matter. Hence Boethius says (De Trin.): "A simple form cannot be a subject." Its self-subsistence is derived from the nature of its form, which does not supervene to the things subsisting, but gives actual existence to the matter and makes it subsist as an individual. On this account, therefore, he ascribes hypostasis to matter, and _ousiosis,_ or subsistence, to the form, because the matter is the principle of substanding, and form is the principle of subsisting. _______________________

Whether the Word "Person" Should Be Said of God?

Objection 1: It would seem that the name "person" should not be said of God. For Dionysius says (Div. Nom.): "No one should ever dare to say or think anything of the supersubstantial and hidden Divinity, beyond what has been divinely expressed to us by the oracles." But the name "person" is not expressed to us in the Old or New Testament. Therefore "person" is not to be applied to God.

Obj. 2: Further, Boethius says (De Duab. Nat.): "The word person seems to be taken from those persons who represented men in comedies and tragedies. For person comes from sounding through [personando], since a greater volume of sound is produced through the cavity in the mask. These "persons" or masks the Greeks called _prosopa,_ as they were placed on the face and covered the features before the eyes." This, however, can apply to God only in a metaphorical sense. Therefore the word "person" is only applied to God metaphorically.

Obj. 3: Further, every person is a hypostasis. But the word "hypostasis" does not apply to God, since, as Boethius says (De Duab. Nat.), it signifies what is the subject of accidents, which do not exist in God. Jerome also says (Ep. ad Damas.) that, "in this word hypostasis, poison lurks in honey." Therefore the word "person" should not be said of God.

Obj. 4: Further, if a definition is denied of anything, the thing defined is also denied of it. But the definition of "person," as given above, does not apply to God. Both because reason implies a discursive knowledge, which does not apply to God, as we proved above (Q. 14, A. 12); and thus God cannot be said to have "a rational nature." And also because God cannot be called an individual substance, since the principle of individuation is matter; while God is immaterial: nor is He the subject of accidents, so as to be called a substance. Therefore the word "person" ought not to be attributed to God.

_On the contrary,_ In the Creed of Athanasius we say: "One is the person of the Father, another of the Son, another of the Holy Ghost."

_I answer that,_ "Person" signifies what is most perfect in all nature--that is, a subsistent individual of a rational nature. Hence, since everything that is perfect must be attributed to God, forasmuch as His essence contains every perfection, this name "person" is fittingly applied to God; not, however, as it is applied to creatures, but in a more excellent way; as other names also, which, while giving them to creatures, we attribute to God; as we showed above when treating of the names of God (Q. 13, A. 2).

Reply Obj. 1: Although the word "person" is not found applied to God in Scripture, either in the Old or New Testament, nevertheless what the word signifies is found to be affirmed of God in many places of Scripture; as that He is the supreme self-subsisting being, and the most perfectly intelligent being. If we could speak of God only in the very terms themselves of Scripture, it would follow that no one could speak about God in any but the original language of the Old or New Testament. The urgency of confuting heretics made it necessary to find new words to express the ancient faith about God. Nor is such a kind of novelty to be shunned; since it is by no means profane, for it does not lead us astray from the sense of Scripture. The Apostle warns us to avoid "profane novelties of words" (1 Tim. 6:20).

Reply Obj. 2: Although this name "person" may not belong to God as regards the origin of the term, nevertheless it excellently belongs to God in its objective meaning. For as famous men were represented in comedies and tragedies, the name "person" was given to signify those who held high dignity. Hence, those who held high rank in the Church came to be called "persons." Thence by some the definition of person is given as "hypostasis distinct by reason of dignity." And because subsistence in a rational nature is of high dignity, therefore every individual of the rational nature is called a "person." Now the dignity of the divine nature excels every other dignity; and thus the name "person" pre-eminently belongs to God.

Reply Obj. 3: The word "hypostasis" does not apply to God as regards its source of origin, since He does not underlie accidents; but it applies to Him in its objective sense, for it is imposed to signify the subsistence. Jerome said that "poison lurks in this word," forasmuch as before it was fully understood by the Latins, the heretics used this term to deceive the simple, to make people profess many essences as they profess several hypostases, inasmuch as the word "substance," which corresponds to hypostasis in Greek, is commonly taken amongst us to mean essence.

Reply Obj. 4: It may be said that God has a rational _nature,_ if reason be taken to mean, not discursive thought, but in a general sense, an intelligent nature. But God cannot be called an "individual" in the sense that His individuality comes from matter; but only in the sense which implies incommunicability. "Substance" can be applied to God in the sense of signifying self-subsistence. There are some, however, who say that the definition of Boethius, quoted above (A. 1), is not a definition of person in the sense we use when speaking of persons in God. Therefore Richard of St. Victor amends this definition by adding that "Person" in God is "the incommunicable existence of the divine nature." _______________________

Whether This Word "Person" Signifies Relation?

Objection 1: It would seem that this word "person," as applied to God, does not signify relation, but substance. For Augustine says (De Trin. vii, 6): "When we speak of the person of the Father, we mean nothing else but the substance of the Father, for person is said in regard to Himself, and not in regard to the Son."

Obj. 2: Further, the interrogation "What?" refers to essence. But, as Augustine says: "When we say there are three who bear witness in heaven, the Father, the Word, and the Holy Ghost, and it is asked, Three what? the answer is, Three persons." Therefore person signifies essence.

Obj. 3: According to the Philosopher (Metaph. iv), the meaning of a word is its definition. But the definition of "person" is this: "The individual substance of the rational nature," as above stated. Therefore "person" signifies substance.

Obj. 4: Further, person in men and angels does not signify relation, but something absolute. Therefore, if in God it signified relation, it would bear an equivocal meaning in God, in man, and in angels.

_On the contrary,_ Boethius says (De Trin.) that "every word that refers to the persons signifies relation." But no word belongs to person more strictly than the very word "person" itself. Therefore this word "person" signifies relation.

_I answer that,_ A difficulty arises concerning the meaning of this word "person" in God, from the fact that it is predicated plurally of the Three in contrast to the nature of the names belonging to the essence; nor does it in itself refer to another, as do the words which express relation.

Hence some have thought that this word "person" of itself expresses absolutely the divine essence; as this name "God" and this word "Wise"; but that to meet heretical attack, it was ordained by conciliar decree that it was to be taken in a relative sense, and especially in the plural, or with the addition of a distinguishing adjective; as when we say, "Three persons," or, "one is the person of the Father, another of the Son," etc. Used, however, in the singular, it may be either absolute or relative. But this does not seem to be a satisfactory explanation; for, if this word "person," by force of its own signification, expresses the divine essence only, it follows that forasmuch as we speak of "three persons," so far from the heretics being silenced, they had still more reason to argue. Seeing this, others maintained that this word "person" in God signifies both the essence and the relation. Some of these said that it signifies directly the essence, and relation indirectly, forasmuch as "person" means as it were "by itself one" [per se una]; and unity belongs to the essence. And what is "by itself" implies relation indirectly; for the Father is understood to exist "by Himself," as relatively distinct from the Son. Others, however, said, on the contrary, that it signifies relation directly; and essence indirectly; forasmuch as in the definition of "person" the term nature is mentioned indirectly; and these come nearer to the truth.

To determine the question, we must consider that something may be included in the meaning of a less common term, which is not included in the more common term; as "rational" is included in the meaning of "man," and not in the meaning of "animal." So that it is one thing to ask the meaning of the word animal, and another to ask its meaning when the animal in question is man. Also, it is one thing to ask the meaning of this word "person" in general; and another to ask the meaning of "person" as applied to God. For "person" in general signifies the individual substance of a rational figure. The individual in itself is undivided, but is distinct from others. Therefore "person" in any nature signifies what is distinct in that nature: thus in human nature it signifies this flesh, these bones, and this soul, which are the individuating principles of a man, and which, though not belonging to "person" in general, nevertheless do belong to the meaning of a particular human person.

Now distinction in God is only by relation of origin, as stated above (Q. 28, AA. 2, 3), while relation in God is not as an accident in a subject, but is the divine essence itself; and so it is subsistent, for the divine essence subsists. Therefore, as the Godhead is God so the divine paternity is God the Father, Who is a divine person. Therefore a divine person signifies a relation as subsisting. And this is to signify relation by way of substance, and such a relation is a hypostasis subsisting in the divine nature, although in truth that which subsists in the divine nature is the divine nature itself. Thus it is true to say that the name "person" signifies relation directly, and the essence indirectly; not, however, the relation as such, but as expressed by way of a hypostasis. So likewise it signifies directly the essence, and indirectly the relation, inasmuch as the essence is the same as the hypostasis: while in God the hypostasis is expressed as distinct by the relation: and thus relation, as such, enters into the notion of the person indirectly. Thus we can say that this signification of the word "person" was not clearly perceived before it was attacked by heretics. Hence, this word "person" was used just as any other absolute term. But afterwards it was applied to express relation, as it lent itself to that signification, so that this word "person" means relation not only by use and custom, according to the first opinion, but also by force of its own proper signification.

Reply Obj. 1: This word "person" is said in respect to itself, not to another; forasmuch as it signifies relation not as such, but by way of a substance--which is a hypostasis. In that sense Augustine says that it signifies the essence, inasmuch as in God essence is the same as the hypostasis, because in God what He is, and whereby He is are the same.

Reply Obj. 2: The term "what" refers sometimes to the nature expressed by the definition, as when we ask; What is man? and we answer: A mortal rational animal. Sometimes it refers to the _suppositum,_ as when we ask, What swims in the sea? and answer, A fish. So to those who ask, Three what? we answer, Three persons.

Reply Obj. 3: In God the individual--i.e. distinct and incommunicable substance--includes the idea of relation, as above explained.

Reply Obj. 4: The different sense of the less common term does not produce equivocation in the more common. Although a horse and an ass have their own proper definitions, nevertheless they agree univocally in animal, because the common definition of animal applies to both. So it does not follow that, although relation is contained in the signification of divine person, but not in that of an angelic or of a human person, the word "person" is used in an equivocal sense. Though neither is it applied univocally, since nothing can be said univocally of God and creatures (Q. 13, A. 5). _______________________

THE PLURALITY OF PERSONS IN GOD (In Four Articles)

We are now led to consider the plurality of the persons: about which there are four points of inquiry:

(1) Whether there are several persons in God?

(3) What the numeral terms signify in God?

(4) The community of the term "person." _______________________

Whether There Are Several Persons in God?

Objection 1: It would seem that there are not several persons in God. For person is "the individual substance of a rational nature." If then there are several persons in God, there must be several substances; which appears to be heretical.

Obj. 2: Further, Plurality of absolute properties does not make a distinction of persons, either in God, or in ourselves. Much less therefore is this effected by a plurality of relations. But in God there is no plurality but of relations (Q. 28, A. 3). Therefore there cannot be several persons in God.

Obj. 3: Further, Boethius says of God (De Trin. i), that "this is truly one which has no number." But plurality implies number. Therefore there are not several persons in God.

Obj. 4: Further, where number is, there is whole and part. Thus, if in God there exist a number of persons, there must be whole and part in God; which is inconsistent with the divine simplicity.

_On the contrary,_ Athanasius says: "One is the person of the Father, another of the Son, another of the Holy Ghost." Therefore the Father, and the Son, and the Holy Ghost are several persons.

_I answer that,_ It follows from what precedes that there are several persons in God. For it was shown above (Q. 29, A. 4) that this word "person" signifies in God a relation as subsisting in the divine nature. It was also established (Q. 28, A. 1) that there are several real relations in God; and hence it follows that there are also several realities subsistent in the divine nature; which means that there are several persons in God.

Reply Obj. 1: The definition of "person" includes "substance," not as meaning the essence, but the _suppositum_ which is made clear by the addition of the term "individual." To signify the substance thus understood, the Greeks use the name "hypostasis." So, as we say, "Three persons," they say "Three hypostases." We are not, however, accustomed to say Three substances, lest we be understood to mean three essences or natures, by reason of the equivocal signification of the term.

Reply Obj. 2: The absolute properties in God, such as goodness and wisdom, are not mutually opposed; and hence, neither are they really distinguished from each other. Therefore, although they subsist, nevertheless they are not several subsistent realities--that is, several persons. But the absolute properties in creatures do not subsist, although they are really distinguished from each other, as whiteness and sweetness; on the other hand, the relative properties in God subsist, and are really distinguished from each other (Q. 28, A. 3). Hence the plurality of persons in God.

Reply Obj. 3: The supreme unity and simplicity of God exclude every kind of plurality of absolute things, but not plurality of relations. Because relations are predicated relatively, and thus the relations do not import composition in that of which they are predicated, as Boethius teaches in the same book.

Reply Obj. 4: Number is twofold, simple or absolute, as two and three and four; and number as existing in things numbered, as two men and two horses. So, if number in God is taken absolutely or abstractedly, there is nothing to prevent whole and part from being in Him, and thus number in Him is only in our way of understanding; forasmuch as number regarded apart from things numbered exists only in the intellect. But if number be taken as it is in the things numbered, in that sense as existing in creatures, one is part of two, and two of three, as one man is part of two men, and two of three; but this does not apply to God, because the Father is of the same magnitude as the whole Trinity, as we shall show further on (Q. 42, AA. 1, 4). _______________________

Whether There Are More Than Three Persons in God?

Objection 1: It would seem that there are more than three persons in God. For the plurality of persons in God arises from the plurality of the relative properties as stated above (A. 1). But there are four relations in God as stated above (Q. 28, A. 4), paternity, filiation, common spiration, and procession. Therefore there are four persons in God.

Obj. 2: The nature of God does not differ from His will more than from His intellect. But in God, one person proceeds from the will, as love; and another proceeds from His nature, as Son. Therefore another proceeds from His intellect, as Word, besides the one Who proceeds from His nature, as Son; thus again it follows that there are not only three persons in God.

Obj. 3: Further, the more perfect a creature is, the more interior operations it has; as a man has understanding and will beyond other animals. But God infinitely excels every creature. Therefore in God not only is there a person proceeding from the will, and another from the intellect, but also in an infinite number of ways. Therefore there are an infinite number of persons in God.

Obj. 4: Further, it is from the infinite goodness of the Father that He communicates Himself infinitely in the production of a divine person. But also in the Holy Ghost is infinite goodness. Therefore the Holy Ghost produces a divine person; and that person another; and so to infinity.

Obj. 5: Further, everything within a determinate number is measured, for number is a measure. But the divine persons are immense, as we say in the Creed of Athanasius: "The Father is immense, the Son is immense, the Holy Ghost is immense." Therefore the persons are not contained within the number three.

_On the contrary,_ It is said: "There are three who bear witness in heaven, the Father, the Word, and the Holy Ghost" (1 John 5:7). To those who ask, "Three what?" we answer, with Augustine (De Trin. vii, 4), "Three persons." Therefore there are but three persons in God.

_I answer that,_ As was explained above, there can be only three persons in God. For it was shown above that the several persons are the several subsisting relations really distinct from each other. But a real distinction between the divine relations can come only from relative opposition. Therefore two opposite relations must needs refer to two persons: and if any relations are not opposite they must needs belong to the same person. Since then paternity and filiation are opposite relations, they belong necessarily to two persons. Therefore the subsisting paternity is the person of the Father; and the subsisting filiation is the person of the Son. The other two relations are not opposed to each other; therefore these two cannot belong to one person: hence either one of them must belong to both of the aforesaid persons; or one must belong to one person, and the other to the other. Now, procession cannot belong to the Father and the Son, or to either of them; for thus it would follows that the procession of the intellect, which in God is generation, wherefrom paternity and filiation are derived, would issue from the procession of love, whence spiration and procession are derived, if the person generating and the person generated proceeded from the person spirating; and this is against what was laid down above (Q. 27, AA. 3, 4). We must consequently admit that spiration belongs to the person of the Father, and to the person of the Son, forasmuch as it has no relative opposition either to paternity or to filiation; and consequently that procession belongs to the other person who is called the person of the Holy Ghost, who proceeds by way of love, as above explained. Therefore only three persons exist in God, the Father, the Son, and the Holy Ghost.

Reply Obj. 1: Although there are four relations in God, one of them, spiration, is not separated from the person of the Father and of the Son, but belongs to both; thus, although it is a relation, it is not called a property, because it does not belong to only one person; nor is it a personal relation--i.e. constituting a person. The three relations--paternity, filiation, and procession--are called personal properties, constituting as it were the persons; for paternity is the person of the Father, filiation is the person of the Son, procession is the person of the Holy Ghost proceeding.

Reply Obj. 2: That which proceeds by way of intelligence, as word, proceeds according to similitude, as also that which proceeds by way of nature; thus, as above explained (Q. 27, A. 3), the procession of the divine Word is the very same as generation by way of nature. But love, as such, does not proceed as the similitude of that whence it proceeds; although in God love is co-essential as being divine; and therefore the procession of love is not called generation in God.

Reply Obj. 3: As man is more perfect than other animals, he has more intrinsic operations than other animals, because his perfection is something composite. Hence the angels, who are more perfect and more simple, have fewer intrinsic operations than man, for they have no imagination, or feeling, or the like. In God there exists only one real operation--that is, His essence. How there are in Him two processions was above explained (Q. 27, AA. 1, 4).

Reply Obj. 4: This argument would prove if the Holy Ghost possessed another goodness apart from the goodness of the Father; for then if the Father produced a divine person by His goodness, the Holy Ghost also would do so. But the Father and the Holy Ghost have one and the same goodness. Nor is there any distinction between them except by the personal relations. So goodness belongs to the Holy Ghost, as derived from another; and it belongs to the Father, as the principle of its communication to another. The opposition of relation does not allow the relation of the Holy Ghost to be joined with the relation of principle of another divine person; because He Himself proceeds from the other persons who are in God.

Reply Obj. 5: A determinate number, if taken as a simple number, existing in the mind only, is measured by one. But when we speak of a number of things as applied to the persons in God, the notion of measure has no place, because the magnitude of the three persons is the same (Q. 42, AA. 1, 4), and the same is not measured by the same. _______________________

Whether the Numeral Terms Denote Anything Real in God?

Objection 1: It would seem that the numeral terms denote something real in God. For the divine unity is the divine essence. But every number is unity repeated. Therefore every numeral term in God signifies the essence; and therefore it denotes something real in God.

Obj. 2: Further, whatever is said of God and of creatures, belongs to God in a more eminent manner than to creatures. But the numeral terms denote something real in creatures; therefore much more so in God.

Obj. 3: Further, if the numeral terms do not denote anything real in God, and are introduced simply in a negative and removing sense, as plurality is employed to remove unity, and unity to remove plurality; it follows that a vicious circle results, confusing the mind and obscuring the truth; and this ought not to be. Therefore it must be said that the numeral terms denote something real in God.

_On the contrary,_ Hilary says (De Trin. iv): "If we admit companionship"--that is, plurality--"we exclude the idea of oneness and of solitude;" and Ambrose says (De Fide i): "When we say one God, unity excludes plurality of gods, and does not imply quantity in God." Hence we see that these terms are applied to God in order to remove something; and not to denote anything positive.

_I answer that,_ The Master (Sent. i, D, 24) considers that the numeral terms do not denote anything positive in God, but have only a negative meaning. Others, however, assert the contrary.

In order to resolve this point, we may observe that all plurality is a consequence of division. Now division is twofold; one is material, and is division of the continuous; from this results number, which is a species of quantity. Number in this sense is found only in material things which have quantity. The other kind of division is called formal, and is effected by opposite or diverse forms; and this kind of division results in a multitude, which does not belong to a genus, but is transcendental in the sense in which being is divided by one and by many. This kind of multitude is found only in immaterial things.

Some, considering only that multitude which is a species of discrete quantity, and seeing that such kind of quantity has no place in God, asserted that the numeral terms do not denote anything real in God, but remove something from Him. Others, considering the same kind of multitude, said that as knowledge exists in God according to the strict sense of the word, but not in the sense of its genus (as in God there is no such thing as a quality), so number exists in God in the proper sense of number, but not in the sense of its genus, which is quantity.

But we say that numeral terms predicated of God are not derived from number, a species of quantity, for in that sense they could bear only a metaphorical sense in God, like other corporeal properties, such as length, breadth, and the like; but that they are taken from multitude in a transcendent sense. Now multitude so understood has relation to the many of which it is predicated, as "one" convertible with "being" is related to being; which kind of oneness does not add anything to being, except a negation of division, as we saw when treating of the divine unity (Q. 11, A. 1); for "one" signifies undivided being. So, of whatever we say "one," we imply its undivided reality: thus, for instance, "one" applied to man signifies the undivided nature or substance of a man. In the same way, when we speak of many things, multitude in this latter sense points to those things as being each undivided in itself.

But number, if taken as a species of quantity, denotes an accident added to being; as also does "one" which is the principle of that number. Therefore the numeral terms in God signify the things of which they are said, and beyond this they add negation only, as stated (Sent. i, D, 24); in which respect the Master was right (Sent. i, D, 24). So when we say, the essence is one, the term "one" signifies the essence undivided; and when we say the person is one, it signifies the person undivided; and when we say the persons are many, we signify those persons, and their individual undividedness; for it is of the very nature of multitude that it should be composed of units.

Reply Obj. 1: One, as it is a transcendental, is wider and more general than substance and relation. And so likewise is multitude; hence in God it may mean both substance and relation, according to the context. Still, the very signification of such names adds a negation of division, beyond substance and relation; as was explained above.

Reply Obj. 2: Multitude, which denotes something real in creatures, is a species of quantity, and cannot be used when speaking of God: unlike transcendental multitude, which adds only indivision to those of which it is predicated. Such a kind of multitude is applicable to God.

Reply Obj. 3: "One" does not exclude multitude, but division, which logically precedes one or multitude. Multitude does not remove unity, but division from each of the individuals which compose the multitude. This was explained when we treated of the divine unity (Q. 11, A. 2).

It must be observed, nevertheless, that the opposite arguments do not sufficiently prove the point advanced. Although the idea of solitude is excluded by plurality, and the plurality of gods by unity, it does not follow that these terms express this signification alone. For blackness is excluded by whiteness; nevertheless, the term whiteness does not signify the mere exclusion of blackness. _______________________

Whether This Term "Person" Can Be Common to the Three Persons?

Objection 1: It would seem that this term "person" cannot be common to the three persons. For nothing is common to the three persons but the essence. But this term "person" does not signify the essence directly. Therefore it is not common to all three.

Obj. 2: Further, the common is the opposite to the incommunicable. But the very meaning of person is that it is incommunicable; as appears from the definition given by Richard of St. Victor (Q. 29, A. 3, ad 4). Therefore this term "person" is not common to all the three persons.

Obj. 3: Further, if the name "person" is common to the three, it is common either really, or logically. But it is not so really; otherwise the three persons would be one person; nor again is it so logically; otherwise person would be a universal. But in God there is neither universal nor particular; neither genus nor species, as we proved above (Q. 3, A. 5). Therefore this term 'person' is not common to the three.

_On the contrary,_ Augustine says (De Trin. vii, 4) that when we ask, "Three what?" we say, "Three persons," because what a person is, is common to them.

_I answer that,_ The very mode of expression itself shows that this term "person" is common to the three when we say "three persons"; for when we say "three men" we show that "man" is common to the three. Now it is clear that this is not community of a real thing, as if one essence were common to the three; otherwise there would be only one person of the three, as also one essence.

What is meant by such a community has been variously determined by those who have examined the subject. Some have called it a community of exclusion, forasmuch as the definition of "person" contains the word "incommunicable." Others thought it to be a community of intention, as the definition of person contains the word "individual"; as we say that to be a species is common to horse and ox. Both of these explanations, however, are excluded by the fact that "person" is not a name of exclusion nor of intention, but the name of a reality. We must therefore resolve that even in human affairs this name "person" is common by a community of idea, not as genus or species, but as a vague individual thing. The names of genera and species, as man or animal, are given to signify the common natures themselves, but not the intentions of those common natures, signified by the terms genus or species. The vague individual thing, as "some man," signifies the common nature with the determinate mode of existence of singular things--that is, something self-subsisting, as distinct from others. But the name of a designated singular thing signifies that which distinguishes the determinate thing; as the name Socrates signifies this flesh and this bone. But there is this difference--that the term "some man" signifies the nature, or the individual on the part of its nature, with the mode of existence of singular things; while this name "person" is not given to signify the individual on the part of the nature, but the subsistent reality in that nature. Now this is common in idea to the divine persons, that each of them subsists distinctly from the others in the divine nature. Thus this name "person" is common in idea to the three divine persons.

Reply Obj. 1: This argument is founded on a real community.

Reply Obj. 2: Although person is incommunicable, yet the mode itself of incommunicable existence can be common to many.

Reply Obj. 3: Although this community is logical and not real, yet it does not follow that in God there is universal or particular, or genus, or species; both because neither in human affairs is the community of person the same as community of genus or species; and because the divine persons have one being; whereas genus and species and every other universal are predicated of many which differ in being. _______________________

OF WHAT BELONGS TO THE UNITY OR PLURALITY IN GOD (In Four Articles)

We now consider what belongs to the unity or plurality in God; which gives rise to four points of inquiry:

(2) Whether we can say that the Son is other than the Father?

(3) Whether an exclusive term, which seems to exclude otherness, can be joined to an essential name in God?

(4) Whether it can be joined to a personal term? _______________________

Objection 1: It would seem there is not trinity in God. For every name in God signifies substance or relation. But this name "Trinity" does not signify the substance; otherwise it would be predicated of each one of the persons: nor does it signify relation; for it does not express a name that refers to another. Therefore the word "Trinity" is not to be applied to God.

Obj. 2: Further, this word "trinity" is a collective term, since it signifies multitude. But such a word does not apply to God; as the unity of a collective name is the least of unities, whereas in God there exists the greatest possible unity. Therefore this word "trinity" does not apply to God.

Obj. 3: Further, every trine is threefold. But in God there is not triplicity; since triplicity is a kind of inequality. Therefore neither is there trinity in God.

Obj. 4: Further, all that exists in God exists in the unity of the divine essence; because God is His own essence. Therefore, if Trinity exists in God, it exists in the unity of the divine essence; and thus in God there would be three essential unities; which is heresy.

Obj. 5: Further, in all that is said of God, the concrete is predicated of the abstract; for Deity is God and paternity is the Father. But the Trinity cannot be called trine; otherwise there would be nine realities in God; which, of course, is erroneous. Therefore the word trinity is not to be applied to God.

_On the contrary,_ Athanasius says: "Unity in Trinity; and Trinity in Unity is to be revered."

_I answer that,_ The name "Trinity" in God signifies the determinate number of persons. And so the plurality of persons in God requires that we should use the word trinity; because what is indeterminately signified by plurality, is signified by trinity in a determinate manner.

Reply Obj. 1: In its etymological sense, this word "Trinity" seems to signify the one essence of the three persons, according as trinity may mean trine-unity. But in the strict meaning of the term it rather signifies the number of persons of one essence; and on this account we cannot say that the Father is the Trinity, as He is not three persons. Yet it does not mean the relations themselves of the Persons, but rather the number of persons related to each other; and hence it is that the word in itself does not express regard to another.

Reply Obj. 2: Two things are implied in a collective term, plurality of the _supposita,_ and a unity of some kind of order. For "people" is a multitude of men comprehended under a certain order. In the first sense, this word "trinity" is like other collective words; but in the second sense it differs from them, because in the divine Trinity not only is there unity of order, but also with this there is unity of essence.

Reply Obj. 3: "Trinity" is taken in an absolute sense; for it signifies the threefold number of persons. "Triplicity" signifies a proportion of inequality; for it is a species of unequal proportion, according to Boethius (Arithm. i, 23). Therefore in God there is not triplicity, but Trinity.

Reply Obj. 4: In the divine Trinity is to be understood both number and the persons numbered. So when we say, "Trinity in Unity," we do not place number in the unity of the essence, as if we meant three times one; but we place the Persons numbered in the unity of nature; as the _supposita_ of a nature are said to exist in that nature. On the other hand, we say "Unity in Trinity"; meaning that the nature is in its _supposita._

Reply Obj. 5: When we say, "Trinity is trine," by reason of the number implied, we signify the multiplication of that number by itself; since the word trine imports a distinction in the _supposita_ of which it is spoken. Therefore it cannot be said that the Trinity is trine; otherwise it follows that, if the Trinity be trine, there would be three _supposita_ of the Trinity; as when we say, "God is trine," it follows that there are three _supposita_ of the Godhead. _______________________

Whether the Son Is Other Than the Father?

Objection 1: It would seem that the Son is not other than the Father. For "other" is a relative term implying diversity of substance. If, then, the Son is other than the Father, He must be different from the Father; which is contrary to what Augustine says (De Trin. vii), that when we speak of three persons, "we do not mean to imply diversity."

Obj. 2: Further, whosoever are other from one another, differ in some way from one another. Therefore, if the Son is other than the Father, it follows that He differs from the Father; which is against what Ambrose says (De Fide i), that "the Father and the Son are one in Godhead; nor is there any difference in substance between them, nor any diversity."

Obj. 3: Further, the term alien is taken from _alius_ (other). But the Son is not alien from the Father, for Hilary says (De Trin. vii) that "in the divine persons there is nothing diverse, nothing alien, nothing separable." Therefore the Son is not other than the Father.

Obj. 4: Further, the terms "other person" and "other thing" [alius et aliud] have the same meaning, differing only in gender. So if the Son is another person from the Father, it follows that the Son is a thing apart from the Father.

_On the contrary,_ Augustine [*Fulgentius, De Fide ad Petrum i.] says: "There is one essence of the Father and Son and Holy Ghost, in which the Father is not one thing, the Son another, and the Holy Ghost another; although the Father is one person, the Son another, and the Holy Ghost another."

_I answer that,_ Since as Jerome remarks [*In substance, Ep. lvii.], a heresy arises from words wrongly used, when we speak of the Trinity we must proceed with care and with befitting modesty; because, as Augustine says (De Trin. i, 3), "nowhere is error more harmful, the quest more toilsome, the finding more fruitful." Now, in treating of the Trinity, we must beware of two opposite errors, and proceed cautiously between them--namely, the error of Arius, who placed a Trinity of substance with the Trinity of persons; and the error of Sabellius, who placed unity of person with the unity of essence.