CHAPTER VI: QUESTION 32 THE KNOWABILITY OF THE DIVINE PERSONS

At this point St. Thomas discusses the knowability of the divine persons because he considers their knowability a property of the divine persons that has a reference to us, just as in the treatise on the one God he treats of the knowability of God in the twelfth question. This question contains four articles: 1. Whether the divine persons can be known by natural reason; 2. Whether certain notions are to be attributed to the divine persons; 3. The number of these notions; 4. Whether we can entertain different opinions about the divine persons. First Article: Whether The Unity Of Divine Persons Can Be Known By Natural Reason St. Thomas takes up this problem after the first five questions. Recent theologians generally treat of it in the beginning of the treatise to support the validity of their investigations into the divine processions. The order adopted by St. Thomas is excellent in itself, although from our standpoint it is useful to consider the indemonstrability of this mystery at least briefly in the beginning. We will here consider the problem at some length.

State of the question. The question is well put by St. Thomas in the three difficulties proposed at the beginning of the article. 1. Many Platonic and Neoplatonic philosophers admitted a certain kind of Trinity with three hypostases, namely, the One, the Logos, and the world soul. 2. Richard of St. Victor tried to demonstrate the Trinity from the infinity of the divine goodness, which communicates itself infinitely in the procession of the three divine persons and from the fact that there can be no joyous possession of any good without some consort or association in that enjoyment. In a similar way, St. Augustine proceeded to show the Trinity of persons from the procession of the word and of love in our human minds. 3. If the mystery of the Trinity had no relation to our reason, its revelation would seem to be superfluous.

We might add that Abelard tried to demonstrate the Trinity.[333] St. Anselm frequently attempted to construct demonstrations to prove the Trinity and sometimes indulged in what were at least wordy extravagances. In recent times Guenther also wished to demonstrate this mystery,[334] as did Rosmini, who brought down on himself the Church's condemnation.[335] More recently Schell, in opposition to the rationalists and Unitarians, who said this mystery was openly opposed to reason, tried to prove the Trinity from the nexus between aseity and immanent processions.[336]

The reply, however, is in the negative: the Trinity of the divine persons cannot be known by natural reason, that is, it cannot be understood or demonstrated. This statement does not depress but rather pleases the theologian.

The proof is from 1. Scripture; 2. the authority of the Fathers; 3. the definitions and declarations of the Church;[337] 4. theological reasoning.

1. The authority of the Scriptures. From our Lord's words, "No one knoweth the Son, but the Father: neither doth anyone know the Father, but the Son, and he to whom it shall please the Son to reveal Him" (Matt. 11:27), it is clear that the Trinity of the divine persons is above created natural knowledge, even that of the angels. This is confirmed by our Lord's words to St. Peter, "Blessed art thou, Simon Bar-Jona, because flesh and blood hath not revealed it to thee, but My Father who is in heaven" (Matt. 16:17). The second text, it is true, refers directly to the mystery of the Incarnation, but if the incarnation of the Son of God is above natural reason, the mystery of the Trinity is all the more above human reason. Hence Pope Hormisdas in writing to the Emperor Justin said: "No visible or invisible nature is able to investigate the secret of the Trinity."[338]

2. The authority of the Fathers. In his argument sed contra St. Thomas quotes St. Hilary and St. Ambrose. He also adduces the authority of St. Gregory of Nyssa, St. Fulgentius, and St. Jerome.[339] He quotes St. Gregory of Nyssa's words, "No words can express the ineffable depth of this mystery."[340]

3. The authority of the Vatican Council: "The mysteries hidden in God are proposed for our belief and if they had not been divinely revealed they could not be known... . These divine mysteries by their very nature exceed the created intellect and even when they are handed down by revelation and received by faith remain covered with the veil of faith and wrapped up in obscurity for us as long as we are journeying in this life toward the Lord, for we walk not through the species of things but by faith."[341] The same Council declared: "If anyone shall say that the divine revelation does not contain true and proper mysteries, but that all the dogmas of faith can be understood and demonstrated from natural principles by the efforts of reason, let him be anathema."[342]

The Church did not in these words define that the mystery of the Trinity is a mystery properly so called, but it is commonly believed in the Church that the Trinity is supreme among all mysteries, since it is the mystery of God's intimate life, and if this mystery is not essentially supernatural, the other mysteries, of the incarnation of the Son of God, our redemption, the sending of the Holy Ghost, would not be essentially supernatural mysteries. Then these mysteries would not be indemonstrable except for their contingency, since the physical world was not created from eternity but in time, and they would not be indemonstrable by reason of their essential supernatural nature. However, the Council declared: "The divine mysteries are above the created intellect by their very nature to such a degree that even when they are handed down by revelation and received by faith" they cannot be demonstrated. This truth was affirmed against the semirationalists Guenther and Frohschammer.

Several declarations were made by the Church against Guenther.[343] The following propositions by Rosmini were condemned by the Church: "After the mystery of the Trinity had been revealed, its existence can be proved by purely speculative arguments, although these arguments are negative and indirect, and these arguments can reduce this truth to the realm of philosophy so that it becomes a scientific proposition like others in philosophy. If this proposition were denied, the theosophic doctrine of pure reason would not only be incomplete but it would be destroyed because of consequent absurdities."[344] Rosmini's teaching that there are "three supreme forms of being, namely, subjectivity, objectivity, and holiness and, when these forms are transferred to absolute being, they cannot be conceived as anything else than living and subsisting persons," was also condemned.[345]

Guenther taught something like this when he defined personality as the consciousness of oneself. "Consciousness," he said, "presupposes the duality of the subject and the object and the knowledge of their identity. The subject is the Father, the object is the Son or the Word, and their substantial identity is the Holy Ghost." Further he declared, "If in God there were but one person, God would not be conscious of Himself."[346] This last statement is obviously false since God is subsisting intellect itself. Moreover, according to Guenther's theory, there should be not only three who are conscious of themselves but also three consciousnesses in order that there be three personalities, and then in God there would be three intellects. This would be tritheism, and something essential in God would be multiplied.[347]

Because of these different authoritative statements it is clear that the Holy Trinity cannot be known naturally, even after its existence is known by revelation. It is also clear that the real possibility of this mystery cannot be positively demonstrated even after revelation. If once the possibility could be proved, the actual existence would also be proved because in necessary things existence follows possibility, and the Trinity is not contingent as are the Incarnation and the Redemption.

4. The theological proof. In God only that can be known naturally which is necessarily and evidently connected with creatures.

We can know nothing about God naturally except through created effects, as was shown above,[348] and the natural principles which are known from a consideration of created being. But from these created effects, at least those that are natural, we cannot arrive at the knowledge of the Trinity because these effects proceed from the creative power or God's omnipotence, which is common to the entire Trinity and, like the divine intelligence and the divine will, pertains to the unity of the essence and not to the distinction of the persons. Therefore it is impossible to come to the knowledge of the Trinity by natural reason.

The major of this argument is philosophically and theologically certain.[349] The minor is of faith according to the Fourth Lateran Council, which said that the Father, the Son, and the Holy Ghost are "co-omnipotent and co-eternal, one principle of all things."[350] By philosophy and theology it can be shown that omnipotence pertains to the divine nature as it is one and not as it is threefold in the persons, since each person does not have its own proper and distinct omnipotence. Thus created effects do not per se proceed from God as triune but only concomitantly inasmuch as the creative power is one and the same in the three persons. The reader is referred to St. Thomas' article, in which he clarifies this truth more than did his predecessors.

Objection. If created effects were known more perfectly, as they are known, for instance, by the angels, perhaps the Trinity could be known from them.

Reply. An effect, no matter how perfectly it is known, will not lead to the knowledge of the cause except under that aspect by which it proceeds from the cause and according to the dependence of the effect on the cause. Thus a painting makes known the painter, but it does not tell whether the painter was large or small, fat or lean. Created effects, at least natural effects, do not depend on God as triune but only as He is one.

Confirmation. In the body of the article St. Thomas adds two theological arguments. "Anyone who tries to prove the Trinity of persons by natural reason derogates from faith in two ways. 1. He derogates from faith because it is concerned with things that do not appear and are hidden in God... . 2. Such an attempt arouses the derision of non-believers since they are led to believe that we depend on human reasonings and believe because of them." The holy doctor concludes: "We should not try to prove the things that are of faith...; it is enough to make a defense by showing that what faith proclaims is not impossible." He says "make a defense," that is, by solving objections and offering reasons of convenience.

Reply to the first objection. The philosophers did not know a Trinity of persons, but the attributes which were later attributed to the persons. The Neoplatonists spoke of three subordinate hypostases which were not equal and which were quite different from the three equal divine persons. They spoke of 1. the one, which is also the supreme good (the god of Plato); 2. the first intelligence (the god of Aristotle); 3. and the world soul (the god of the Stoics).

Reply to the second objection. Concerning the Trinity, reason can offer non-demonstrative reasons, arguments of convenience. Thus from the infinite goodness of God we are persuaded by an argument of convenience to accept God's fecundity within Himself, but this is no proof. In the same way from the fact that our intellect produces a word we cannot prove that there is a word in God; in us the word is a result of need, in God the word is from superabundance.

Reply to the third objection. Nevertheless the revelation of the Trinity is not without relation to the truths of the natural order, which it confirms. The Trinity confirms the freedom of creation, for if God made all things by His Word, He did not create by a necessity of nature or of knowledge; since He is already fecund within Himself He does not need to create in order to be fecund.[351] The revelation of the Trinity was especially necessary for a correct understanding of the salvation of the human race, which is accomplished by the incarnate Son and by the gift of the Holy Ghost. These two mysteries presuppose the mystery of the Trinity.

First doubt. Whether after the revelation of this mystery it can be clearly demonstrated by reason alone. The reply is in the negative: 1. from the authority of the councils, according to which mysteries in the strict sense cannot be demonstrated even after they are revealed; 2. from theological reason because divine revelation does not indicate that creatures depend and proceed per se from God as triune

Second doubt. Whether the possibility of the mystery of the Trinity at least can be apodictically proved by reason after it has been revealed. The reply is in the negative: 1. because, as has been said, only that can be known naturally in God which necessarily is connected with creatures. But the possibility of the Trinity is no more clearly connected with creatures than its existence, because the creative power is common to the three persons. 2. Moreover, in necessary things existence follows from a real intrinsic possibility as, for instance, if it is true that God can be wise then He is indeed most wise. But the Trinity is not something contingent but necessary. Therefore, if by reason alone we can prove conclusively that the Trinity is intrinsically possible, we would also prove its existence. Such is the reasoning of many Thomists, among them Gonet and Billuart.

Objection. Whatever can be shown to involve no contradiction is proved to be possible. But by reason alone it can be shown that the Trinity involves no contradiction. Therefore it can be proved to be possible, for intrinsic possibility is simple non-repugnance to being.

Reply. I distinguish the major: if it can be shown positively and evidently to involve no contradiction, I concede; if only negatively and probably, I deny.[352] Thus St. Thomas says: "Theology makes use of philosophy to counter those things which are said against the faith by showing either that these things are false or that they are not necessary."[353] This means, Billuart notes, when we solve the objections from reason and the contradictions which oppose the possibility of this mystery, we show that these arguments are at least not necessary or cogent. It suffices that this mystery be not judged to be impossible, but not that it is evidently possible.[354] We have shown that the possibility of this mystery cannot be disproved, nor can it be strictly proved because we have here a mystery in the strict sense, which has no necessary and evident connection with creatures that are naturally knowable. The reason given by St. Thomas in the body of the article is entirely formal. In order to understand the possibility of this mystery we must be able to see that if God were not triune He would not be God just as we see that if God were not omnipotent He would not be God. This truth is not manifest even in the extraordinary intellectual visions which are granted by means of infused species such as the angels possess; this truth cannot be seen except when the essence of God itself is seen, and God's essence cannot be known as it is in itself by any created species.[355]

I insist. No middle exists between the possible and the impossible. But the rationalists cannot prove that this mystery is impossible. Therefore the theologians can prove that it is possible.

Reply. I deny the consequence. Although no middle exists between the possible and impossible, a middle does exist between the demonstration of possibility and the demonstration of impossibility, for the possibility of the Trinity is plausible although it cannot be proved. So it is with all mysteries that transcend demonstration; they are not contrary to reason, they are above it. Their possibility cannot be positively proved or disproved; it is only plausible. Such is the possibility of the Incarnation, of eternal life, of the beatific vision, of the light of glory, and the possibility of grace, which is the seed of glory.

I insist. In the treatise on the Trinity it is at least shown that the Trinity implies no contradiction. Therefore it is possible.

Reply. I distinguish the antecedent: that we see clearly that the Trinity implies no contradiction, this I deny; that it appears plausible, this I concede. We say, for instance, that in God to be begotten is not less perfect than to beget, that to be spirated is not less perfect than to spirate, but this is not evident. We cannot prove conclusively that passive generation imputes no imperfection in the Son of God; we only indicate it with some probability while it is revealed elsewhere.

I insist. God as one is no less supernatural than as triune. But God as one can be naturally known. Therefore He can be known naturally also as triune.

Reply. I distinguish the major: God as one is no less supernatural in being as He is in Himself, I concede; as a knowable object with regard to creatures, I deny. I distinguish the minor: God is known in this way by creatures, I concede; otherwise, I deny.

Third doubt. Whether reason by itself alone can find analogies to make known the divine processions. For example, if the Son of God had not been called the Word of God in St. John's Gospel, would St. Augustine have been able to discover the analogy of our mental word with the Word of God?

We reply with St. Thomas.[356]

1. St. Augustine would not have been able, before the revelation of the Trinity, to propose this analogy in such a way that it would have led him to certitude about the existence of the Trinity.

2. But after the Trinity was revealed he would have been able to propose the analogy as probable. Indeed, it is more than probable that the analogy was not discovered by St. Augustine, but that it is to some extent revealed in the prologue of St. John's Gospel.

Explanation. In his reply to the second difficulty, St. Thomas says concerning the arguments of fitness given by St. Augustine and Richard of St. Victor: "Once the Trinity has been established, these arguments show its congruity but not in such a way that they would be able to prove the Trinity of persons... . So, in astronomy, in order to explain the movement of the planets, a system of eccentrics and epicycles is adopted in order to explain the sensible appearances of heavenly movements, but these theories are not sufficient to prove anything, because these appearances could be proved by some other theory."

St. Thomas adds that this is clear in these individual instances.

1. With regard to the divine goodness being diffusive of itself. It is proposed as an argument of fitness that good is essentially diffusive of itself and the higher the good the more intimately and abundantly is it diffusive. Hence it is congruous that God the Father should beget the Son and with Him spirate the Holy Ghost in the unity of nature. But this is only an argument of congruity, for, as the Angelic Doctor says: "It is not necessary, if God is to communicate Himself in His infinite goodness, that some infinite being should proceed from God, but that some being should receive the divine goodness according to its own mode of being." Thus it was that God created from nothing finite beings because of His infinite goodness. By this argument it cannot be demonstrated that God is infinitely fecund within Himself by that certain diffusion of goodness which exceeds the order of efficient and final causality and takes place by the communication of the divine nature itself to two uncreated persons.

2. Richard of St. Victor declared that there can be no joyous possession of any good without friendship or association, and from this argument of fitness he showed that there should be in God some association between distinct persons. This argument is not demonstrative because the alleged principle applies when perfect goodness is not found in one person and therefore this person requires the good of another person associated with itself in order to enjoy goodness fully. But God is essentially goodness itself and He possesses it fully and thus He differs entirely from a created person who needs the association of friends. If there is any association in God, it exists not because of a need but because of superabundance. Thus this argument is only an argument of congruity and not demonstrative.

3. Nor from the fact that our intellect enunciates a mental word does it follow necessarily that the Word is in God. Intellect is not found in God and in us univocally, and we have seen above that God, who is subsisting intelligence itself, does not need an accidental word for intellection.[357] Hence, if the Word is in God, it is not accidental but substantial; moreover the Word is not because of need but because of superabundance, and this can be known only by revelation.

Hence, according to St. Thomas, reason of itself alone did not discover these congruities, but after revelation it could propose such arguments. This mystery is properly speaking essentially supernatural, transcending the spheres of demonstration and demonstrability. In this essentially supernatural order we cannot penetrate farther than to those things that are formally or virtually revealed; beyond that we are in the realm of probability.

Fourth doubt. Whether, after revelation, these arguments of congruity can explain with some probability the divine processions as they are in themselves, or are they only convenient and useful representations without any foundation in the divine reality.

Reply. Perhaps many would reply by taking the stand that many modern critics take with regard to physical science: that these theories do not intend to explain how things are in reality, that they are only convenient representations useful in classifying known phenomena which are subject to change when other phenomena are discovered, as, for instance, in the case of radioactivity.

Following St. Thomas, we reply that these arguments of congruity with respect to the Trinity are not only convenient representations, but they explain reality with some probability, or rather they explain what is not in God. Such explanations are the more valid the more they are based on revelation. Indeed it appears that the formal mode of the first procession by intellectual diction, if not formally revealed by the fact that the Son of God is called the Word, is at least certain as a virtually revealed theological conclusion. But many of the other conclusions remain only probable.

Fifth doubt. Whether these arguments of congruity about the Trinity are simply superior or inferior to the demonstrations given in the treatise on the one God.

Reply. With regard to us, that is with regard to the mode and certitude of our knowledge, they are inferior; but in themselves they are superior with regard to the dignity of the object, because they are not beneath but above the sphere of demonstrability, and in the essentially supernatural order we cannot ascend higher than those things that are either formally or virtually revealed except in the sphere of probability.

Hence it is that semirationalists, like Guenther and Rosmini, who wish to transform these arguments of congruity into demonstrations really weaken rather than elevate them. This is clear from Rosmini's condemned proposition: "By these arguments the truth of the Trinity is brought within the scope of philosophy."[358]

Against this view St. Thomas remarks: "It is useful for the human mind to exercise itself in arguments of this kind, however weak they may be, as long as there is no presumption of comprehending or understanding, because it is a great satisfaction to behold these sublime matters even if our consideration is slight and weak."[359]

Thus our natural and inefficacious desire of seeing God in His essence is not a demonstration but it forcefully insinuates the possibility and congruity of eternal life, of the beatific vision, of the light of glory, and of inchoate and consummated grace. This possibility cannot be demonstrated because it is the possibility of something that is essentially supernatural, of a mystery in the strict sense, which transcends reason and demonstrability.[360]

These arguments of congruity are related to evidence and certitude in the same way that a polygon is related to the circumference of a circle. The sides of the polygon can be multiplied to infinity, but the polygon will never be identified with the circumference because it will never be as small as a point. In geometry we say that the polygon will be the circumference at the limit of multiplication, but multiplication is indefinite. Great theologians and the angels, by their natural cognition, can penetrate deeper and deeper into the arguments of congruity about the Trinity and never attain to evidence, because the evidence which-is beyond the limit of this progressive penetration is not the natural evidence of demonstration but the supernatural evidence of the beatific vision. These arguments are like the element of cogitation in faith, if we define the act of faith as, "No believe is to think with assent."[361] Such thinking in this life never reaches evidence; only in heaven, where faith ceases because it cannot exist alongside vision.[362]

Recapitulation of the solution of the principal objections against the Trinity.[363]

According to the rationalists the dogma of the Trinity is a violation of the principles of contradiction and causality.

The first objection often proposed by the rationalists is the following. Those things which are the same as a third are identical. This is a form of the principle of contradiction or identity and is called the principle of comparative identity, on which the validity of the demonstrative syllogism is based. But the three persons are identified with the divine essence (since each one is God). Therefore the three persons cannot be really distinct from one another.

Reply. I distinguish the major: those things which are the same as a third in fact and in reason are identical, I concede; which are the same as a third in fact but not in reason, I deny. I contradistinguish the minor: but the three persons are the same as the divine essence in fact and in reason, I deny; the three persons are the same in fact but not in reason, I concede. I deny the consequent and the consequence.

I insist. Those things which are the same as a third in fact but not in reason are then identical in fact but not in reason. Thus the persons are distinct from each other only in reason but not in reality.

Reply. I distinguish the major: those things which are the same as a third in fact but not in reason are identical in fact but not in reason if they are no more opposed to each other than to the same third, I concede; otherwise, I deny. They are indeed opposed to each other by relative opposition. Just as the three angles of the triangle, although they have the same triangular surface, with which they are identified, nevertheless are really distinguished from each other because between them there is opposition of relation.

I insist. But it seems to be repugnant that the same thing (the essence) should in reality be identical with relations that are distinct from each other and opposed to each other.

Reply. An evident contradiction would exist if the extremes which are opposed to each other were absolutes, because each of the extremes would in itself imply an absolute reality which would be lacking in its opposite. But the contradiction does not appear when the extremes, as in God, are relative. We have seen that the divine persons are constituted by subsisting relations that are opposed to one another; but these relations have one "esse in" and are opposed only with regard to their real "esse ad".

This reply is based on the application of that principle, admitted by the Greeks and the Latins, which illuminates this entire tract, namely, in God all things are one and the same except where there is opposition of relation.[364] Indeed those things that are the same as a third are identical if they are no more opposed to each other than to the third, I concede; otherwise, I deny. I contradistinguish the minor, as follows: but the three persons are the same as the essence and besides this they are opposed to each other by the opposition of relation, this I concede; otherwise, I deny. Therefore I deny the consequent and the consequence.

As in the natural order, "While transitive action is the same as motion and the reception of motion (passio), it does not follow that motion and its reception (actio and passio) are the same, " because they are mutually opposed by the opposition of relation, for transitive action, at least terminatively taken, is motion as from the mover, whereas passio (the reception of motion) is motion as in the one moved. In the words of St. Thomas," assio and actio imply opposite references." Similarly, paternity and filiation, although they are in reality the same as the divine essence, "My their proper natures imply opposite references."[365]

A second objection frequently made is the following. The dogma of the Trinity is a violation of the principle of efficient causality, according to which nothing produces its own being. But in this dogma the person who produces, the Father, and the person produced, the Son, have the same divine essence. Otherwise the Son would not be God.

To put it more briefly: Nothing produces its own being. But the Father in begetting the Son would be producing His own being since it is the same as that of the Son. Therefore the Father cannot beget the Son. This objection is made by many rationalists, by the Unitarians and the Socinians.

Reply. I concede the major. I distinguish the minor: if the divine being were caused in the Son, I concede; if it is communicated to the Son, I deny. The conclusion is distinguished in the same way. Thus begetting in God is not a change from non-being to being, but implies the origin of one living being from a living principle conjoined to it. This principle is not a cause.[366] Aristotle pointed out that a principle is more general than a cause.[367] Thus the point is the principle of the line, but not its cause; the aurora is the principle of the day, but not its cause. So in God the principle does not signify priority, but origin, and the Father does not produce His own being; He communicates it only.

The term "communicate" transcends efficient and final causality. Thus in God to beget is not more perfect than to be begotten because in God begetting is not causing. That which is caused does not exist before in act, whereas that which is communicated exists before in act. For example, the first angle of the triangle communicates its surface, already existing in act, to the other two angles.

The third objection (by way of insistence) states that this dogma distorts the notion of person. For personality renders a nature incommunicable to another suppositum. But the nature which is in the person of the Father is communicated to the Son and to the Holy Ghost. Therefore this dogma distorts the very idea of personality.

Reply. I distinguish the major: absolute personality renders the nature incommunicable, I concede; relative personality renders the divine nature incommunicable, I subdistinguish: nature in itself, I deny; nature as personified, I concede. I contradistinguish the minor: the nature which is in the Father is communicated as nature in itself, I concede; as personified, namely, the divine nature in the mode of the Father, I deny. Thus there cannot be two Fathers or two Sons in the Trinity. Similarly in an equilateral triangle the first angle constructed renders the area of the triangle incommunicable inasmuch as it belongs to that first angle; nevertheless this same area remains communicable and is communicated to the other two angles.

I insist. But the person renders incommunicable a nature that is numerically the same even considered in itself. But this would not be true in God. Therefore.

Reply. A person absolutely renders a finite nature incommunicable which, since it is finite, is filled by the one personality. On the other hand, a relative personality, for example, the person of the Father, does not render an infinite nature incommunicable to other persons. The divine nature, being infinite and infinitely fecund, is not adequately filled by one relative personality; or, I say please prove the contrary. Personality in God differs from human personality inasmuch as it is not something absolute but something relative, and it is of the nature of relative things that they have a correlative. The Father cannot be without the Son, to whom He communicates His nature, not by causality but by the principle of origin.[368] Second Article: Whether There Are Notions In God In this article St. Thomas explains in opposition to Praepositivus of Cremona that it is necessary to express the relations in the abstract, and that the relations in the abstract are called personal properties or notions. Thus paternity is said to be a notion or the objective reason denoting the person of the Father, and filiation likewise is the notion or the proper reason denoting the person of the Son, and similarly procession is the notion denoting the third person.

The reason for having recourse to the abstract notions of paternity, filiation, etc., is that our intellect apprehends God not as He is in Himself as a most simple being, but in the mirror of sensible things, that is, according to our method of knowing sensible things. The simple forms of sensible things are signified by abstract terms, for example, animality, humanity, whereas the suppositum is signified by concrete terms, such as this animal, and this man.

As St. Thomas says,[369] because of their simplicity we designate divine things by abstract terms, and by concrete terms because of their subsistence. Thus we speak of God and, the Deity, of wisdom and a wise man, of paternity and the Father. But we add that God is His own Deity and the Father is His own paternity. Otherwise we would not be able to reply to the heretics who ask how the three persons are one God and how they are three. For the person of the Father there is a special reason since the person of the Father is actively referred to the two other persons by the two relations of paternity and active spiration. These two relations cannot be reduced to one, otherwise filiation and passive spiration would be identified and thus there would be only two persons. Thus we must admit two notions for the Father, namely, paternity and active spiration, and the latter is common to Him and to the Son. Third Article: Whether There Are Five Notions In God This article justifies the accepted mode of speaking of the Trinity. The reply is in the affirmative: five notions are commonly given, namely, innascibility, paternity, filiation, common (active) spiration, and procession.

Such is the general usage of theologians, but Scotus added a sixth, the infecundity of the Holy Ghost. This notion is not acceptable because it does not pertain to the dignity of the Third Person.

In the body of the article St. Thomas shows why there are no more and no less than five notions. A notion is that which is the proper reason for knowing a divine person. But the divine persons are multiplied according to their origin (both active and passive). Therefore according to origin (active and passive) we derive the notions denoting the persons. Thus we have paternity, filiation, common active spiration, passive spiration, to which we add innascibility, because the person of the Father is known not only by paternity but also by the fact that He is from no one and that He is the principle without a principle. This notion is in conformity with the dignity of the Father, but the infecundity of the Holy Ghost is not an expression befitting the dignity of the Third Person.[370]

First corollary. Of these five notions only four are relations, since innascibility is not a relation but the negation of the relation of origin in the Father.

Second corollary. Only four of the notions are properties since common spiration belonging to two persons is not a property.

Third corollary. Of these five notions only three are personal notions, that is, notions constituting persons, since common spiration and innascibility are not personal. As we shall see below, innascibility does not properly constitute the First Person.[371] We shall also see that there are two notional acts, that is, the processions in their active sense, namely, generation and active spiration.

Objection. Innascibility seems to be pure negation and is therefore not a distinct notion because negation adds nothing to the dignity of the person.

Reply. Innascibility signifies that the Father is the principle without principle, and this is a great dignity. On the other hand, infecundity does not pertain to the dignity of the Third Person.[372] Fourth Article: Whether We May Have Contrary Opinions About The Notions This article was written because the Greeks held other opinions about common spiration when they denied the Filioque.

St. Thomas replies that it is lawful to have other opinions about the divine notions provided that no conclusions are reached contrary to the faith proposed by the Church. With regard to the Filioque, we shall learn the doctrine of the Church when we treat in particular of the Holy Ghost as He proceeds from the Father and the Son. This doctrine was defined as early as 381 in the First Council of Constantinople.[373] This concludes the questions concerning the divine persons in common. Recapitulation Of Question 32 In the first question on the Trinity St. Thomas began with the unity of the divine nature and the revealed existence of the processions. He showed that the processions were immanent or ad intra and he explained them according to St. Augustine by analogy with the intellectual enunciation of the word and with love. Thus the processions were seen to be after the manner of intellection and of love. This is based on revelation since it is clear from the prologue of St. John's Gospel that the Son of God proceeds as the intellectual word of the Father.

In the second question he showed how these real processions, namely, generation and spiration, are the bases of real relations according to which the Father, the Son, and the Holy Ghost are denominated in Sacred Scripture. These real relations are not really distinguished from the essence, but they are really distinct from one another if relative opposition exists between them. For it is not repugnant that the relations be mutually opposed; they are indeed not opposed to each other in their "esse in" (for in this they are identified with the essence) but according to their "esse ad", which does not properly inhere in the essence. If, on the contrary, that which is proper to a relation inhered in the subject, as the property of quality, the opposition of relation could not exist between the relations unless at the same time there should be opposition in the divine essence itself. We saw also how St. Thomas solved the objection based on the principle that those things which are the same as a third are identical, whereas Suarez held that the principle of identity does not apply to the Trinity.

In question 29 St. Thomas showed that the divine persons are formally constituted by subsisting relations opposed to one another. Thus he safeguards the analogical notion of person as something subsisting and incommunicable. Hence the divine essence is communicable but the paternity is not.

Then St. Thomas treats of plurality in God, the proper manner of expressing this plurality, and the knowability of this mystery.

St. Thomas thus begins with the unity of the divine nature and the two processions as they are revealed and proceeds to the three divine persons mentioned in revelation. Thus without detracting from the sublimity of this mystery he explains it to some extent by showing that, even after the unity of the divine nature is established, the Trinity of persons is not repugnant. The possibility of the Trinity is not properly and positively demonstrated, but congruent reasons are given to show that the divine nature ought to be fecund, even infinitely, after the manner of intellectual generation and the spiration of love. In this way St. Thomas retained what earlier theologians, like Alexander of Hales and St. Bonaventure, had taught: that the good is diffusive of itself, and that it seems that the higher the good the more intimately it will be diffusive of itself. St. Thomas expressed this idea in his own words: "the higher any nature is, the more intimate with it will be that which proceeds from it."[374]

But, as has been said, with respect to creatures the good is diffusive of itself primarily in the order of final causality and consequently in the order of efficient causality, since everything that acts does so because of some end. The divine processions, however, are above the order of causality, both final and efficient. The Father is not the cause of the Son; He is only the principle. The same is true of the Father and the Son with regard to the Holy Ghost. Hence St. Thomas makes little use of the formula, "Good is diffusive of itself," in this treatise on the Trinity; and in order to express the fecundity of the divine nature he prefers the statement, "My how much higher a nature is so much more intimate will be that which proceeds from that nature," and "By how much greater the understanding so much more intimate will be the intellectual concept with the intellect... . Hence, since the divine intellect is at the apex of perfection, we must say that the divine Word is perfectly one with Him from whom it proceeds without any diversity of nature."[375]

The divine Word is not something accidental; it is substantial because intellection in God is not an accident but something subsisting. The first procession, then, is not the conception of an accidental word but the true generation of the substantial Word. Thus to some degree the mystery is explained notwithstanding its supernatural sublimity. We now turn to the divine persons in particular.