IV
THE MYSTERY OF THE TRIUNE GOD
According to the Creed attributed to St. Athanasius, whoever wishes to be saved must hold to the Catholic faith whole and entire. “The Catholic faith, however, is this: that we adore one God in trinity and trinity in unity, neither mixing the persons nor separating the substance” (Denz. 75). The Athanasian Creed, dating at least to the fourth century, goes on in great detail to profess that “the Father is God, the Son is God, the Holy Spirit is God, but there are not three Gods, but one God.” All are equal in immensity, eternity, omnipotence, lordship, and creation. They are all one God. But each Person is really and truly distinct from the other two, and these Persons are only three: Father, Son, and Holy Spirit. This is the incomprehensible mystery that God has revealed to us about his inner dynamic life.
When philosophers prove the existence of one God (cf. Note 11 above), they prove that in him his very nature or essence is to be ( esse ) . St. Thomas proves this fundamental truth of his philosophy in many ways (See Sum. theol. , I, q.3, a.4 and all parallel places). Simply, in everything that exists, whatever is over and above the essence ( praeter essentiam ) must be caused either by the essence itself (or nature ), as proper characteristics naturally springing forth from it, like risibility in man, or it must be caused by some extrinsic source, like heat in water being caused by fire. But since the very existence of a thing ( ipsum esse rei ) within our experience is other than its essence, then the thing’s existence must be caused either by its essential principles or by some exterior cause. Its own existence cannot in any way be produced by the essential principles of the thing, for then the essence could not but necessarily exist, since whatever is essential necessarily belongs to it. Therefore, the thing whose esse is other than its essence must have its existence caused by another—and ultimately by one whose very essence is to be. Therefore in God essence and existence ( esse ) are identical. Thus God is his nature or essence, and he is his esse or existence. Expressed in more Platonic terms, esse is a reality in which different things share or participate in varying degrees, but whatever is had by participation ( per participationem ) presupposes one who has it essentially ( per essentiam ).
For St. Thomas the splendor of God’s reality is expressed most fully in the identity of his essence and existence. The very nature of God is to be ipsum esse subsistens, “subsistent being itself.” In human history, God, having chosen a special race of people among all those whom he had created, revealed to the Jews his own name, Yahweh, “I AM WHO AM” (Ex 3:14). This truth, as Gilson has constantly emphasized, is the basic principle of the whole of St. Thomas’ philosophy. He has also noted that St. Thomas himself referred to this insight as haec sublimis veritas ( Sum. c. Gent. , I, c.32; see E Gilson The Christian Philosophy of St. Thomas Aquinas, trans. L. K. Shook, New York: Random House, 1956, pp.84-95; Le Thomisme, 6th ed.,: Paris. Vrin, 1965, pp.99-112). It belongs to the nature of God necessarily to exist. That is, he cannot not exist.
From this basic truth it follows, first, that God is in every way uniquely and absolutely indivisible, or “simple,” as St. Thomas puts it, having no distinctions within his nature whatever ( Sum. theol., I, q.3). Thus in God there is no distinction or difference between his intellect and will, truth and love, justice and mercy, and so forth, even though for us each of these words has a real and distinct meaning ( ratio ) that must be retained in our talking about God. In our talking about God, human language does not lose its meaning, but it takes on a subtlety and expansion in which we realize that words are being used differently of God and creatures. The difference is radical and absolute ( per se ), but there is a human reasonableness in using certain words of both God and creatures. This “equivocation by intent,” as Aristotle calls it, is more properly called analogy, which is quite different from simple metaphorical language, such as God’s “walking,” or his “coming down” ( Sum. theol. , 1, q. 13, etc.). Words such as “good” and “love” can be used properly both of God and man, but in two radically different ways; the reality as it is found in God infinitely transcends our conception of “good” and “love” realizable in man. Thus such statements as “God is love” (1 Jn 4:8), God is truth, God is good, and so forth, are more true and significant than we can possibly realize. The meaning such terms have for us is quite real and proper, but our understanding of those terms is but a shadow of the reality that is in God. Similarly, God’s nature is esse in a way that surpasses our understanding of all the things of our human experience.
The second point is that God has revealed to us through the Law and the Prophets, through Jesus Christ, and through his Church, that he, the Father, “so loved the world that he gave his Only Begotten Son, so that whoever believes in him should not perish, but have eternal life” (Jn 3:16). The Son of God-made-man himself stated time and again that he “was sent by the Father” to do the will of him who sent him, and that all he has is “from the Father.” But he also said that he would “ask the Father, and he will give you another Paraclete, to be with you forever—the Spirit of truth” (Jn 14:16-17), “the Paraclete, the Holy Spirit, whom the Father will send in my name, he will teach you all things, and bring to your mind whatever I have said to you” (Jn 14:26). The Son-made-man also said: “When the Paraclete comes, whom I will send you from the Father, the Spirit of truth who comes from the Father, he will give testimony to me” (Jn 15:26). The last injunction of Jesus to his apostles was “go, therefore, and teach all the nations, baptizing them in the name of the Father, and of the Son, and of the Holy Spirit” (Mt 28:19). This baptismal formula reflects the Church’s gradual understanding of God as three Persons (See Acts 2:38; 2 Cor 13:13).
The only words God used in revealing himself to us are those of “Father,” “Son,” and “Holy Spirit” (“Spirit” or “Paraclete,” meaning advocate or comforter). And it is only within this context that the theologian must try to understand the inner life of the Godhead. St. John also uses the word logos, Verbum, or Word, as synonymous for the Son. St. Paul speaks of Christ as “the image of God” (2 Cor 4:4- Col 1:15). There simply are no other words given to us for theological understanding. These are common enough terms, but how they are to be understood of the one God, whose nature is his esse is a difficult problem, where “faith seeks understanding” with the help of philosophy, the age-long “handmaid of theology” (the ancilla theologiae ) as understood by the Alexandrine theologians, particularly St. Athanasius, and by the Cappadocian Fathers (St. Basil of Caesarea, St. Gregory of Nazianzus, and St. Gregory of Nyssa) in the East, and by St. Augustine in the West.
In this note there are two major points that need clarifying. First, the doctrine of consubstantiality of the Son with the Father, which was the first really crucial development in Christian doctrine. Although the debate over this doctrine reached a climax in the fourth century, still there was the subsequent problem of Filioque, which came to a head in the ninth century. The second baffling mystery was how each of the three Persons is identical with the one nature, yet truly distinct from each other.
A. Consubstantiality of the Son with the Father
Frequently in the New Testament Scriptures, Jesus Christ seems to be presented as somehow less than Yahweh, the one true God of the chosen people, he speaks of himself as “sent by the Father” to do not his own will, but “the will of him who sent me.” He always speaks of himself as having only that teaching, that knowledge, that mission, that will, that judgment which has been committed to him by the Father. Throughout the Gospel of St. John, Jesus seems to acknowledge a subservient position to the Father, depending upon the Father’s acceptance and glorification of him as a loyal Son. In the Gospel according to St. John, Jesus even declares explicitly that “the Father is greater than I” (Jn 14:28). In the end he commends his spirit to the Father.
One of the prevalent assumptions of such ecclesiastical writers as Origen and Clement of Alexandria was that the Son, Jesus Christ, was subordinate to the Father. One form of “subordinationism” insisted that Jesus was no more than a mere man who was “adopted” by God. Other forms, like that held by Arius (c.250-c.336), maintained that the Person of Jesus was created by the Father from nothing in order to be the instrument of the divine plan; and thus that the Person of Jesus had a substance ( ousia ) different from God’s. This was the extreme form of Arianism that developed from the “subordinationism” of the third century. A second party that developed in the early fourth century, called “Homoeans” (from homoios, “similar”), tried to avoid the very basic commitment of “What think you of Christ?” by saying that there was much similarity between Father and Son “according to the Scriptures.” But the most influential group to emerge was the Semi-Arians, who claimed that the Father and Son were “similar in substance” ( homoiousios ), but not identical. Although the question of the ousia of Jesus was the central issue that directly occasioned the synod of Alexandria (c.320) in which St. Alexander condemned the teaching of Arius, the Catholic teaching was not universally proclaimed until the Ecumenical Council of Nicaea, convoked by the Emperor Constantine at his summer palace in 325.
At the Council of Nicaea, under the presidency of Hosius of Spain and under the prosecution mainly by Saint Alexander of Alexandria, whose secretary was the deacon St. Athanasius, approximately 235 bishops (318 according to Athanasius) gathered to consider this crucial dogmatic problem and legislate a number of disciplinary decrees. Basing themselves on the texts “In the beginning was the Word... and the Word was God” (Jn 1:1), “The Father and I are one” (Jn 10:30), “That they may be one, even as we are one” (Jn 17:11), “That all may be one, as you Father, in me, and I in you” (Jn 17:21) and similar texts, the conciliar Fathers at Nicaea professed the ancient belief that the “Son is of one substance (that is, homoousion ) with the Father.” The Latin rendering is “consubstantial ( consubstantialis ) with the Father.” This doctrine was directly opposed by the Semi-Arians under the leadership of Eusebius, bishop of Nicomedia. Eusebius and his many followers insisted on the term homoiousion, “of similar substance with the Father,” in place of the orthodox homoousion. Some so-called historians of this controversy of the fourth century have been so insensible and obtuse as to describe it as “a quibble about an iota.” That iota made all the difference in the world between orthodoxy and heresy. As late as 359, St. Jerome could write: “The whole world groaned one day and marvelled to find itself Arian” (Dial. adv. Lucif 19, PL 23, 172C).
The significant point is that the word homoousion is nowhere to be found in the Canonical Scriptures, no more than is homoiusion. But homoousion was a soundly based philosophical term used in response to a Greek philosophical question. Consequently, the crucial question for modern man seeking the Christian truth is not so much “what think you of Christ? Whose Son is he?” (Mt 22:42), but rather, “What think you of homoousion? By what authority do you profess it?” In the earliest ages of Christianity, many thought highly of Jesus as the “adopted son of God,” and accepted him as the “Christus” of faith giving us hope. But, as we shall see, the fundamental question is about the historical Jesus as “consubstantial with the Father,” just as the bishops assembled at Nicaea openly declared to be the true teaching of the Church.
This is one of the earliest examples of the development of Christian doctrine which Cardinal John Henry Newman (1801-90) helped us to understand (See especially his Arians of the Fourth Century (1833), St. Athanasius, 2 vols. (1843), Development of Christian Doctrine (1845)). The real meaning of the text “The Father and I are one” (Jn 10:30) is that the Son is “consubstantial with the Father” ( homoousion toi patri ). In theological terms, the ousia (substance) of the Son is identical to the ousia of the Father. From this it is only a short step to the recognition of the Holy Spirit as consubstantial to the Father and Son; that is, the ousia of the Holy Spirit is identical to that of the Father and the Son. Moreover, that unique ousia is “an individual substance of an intellectual nature”; that is, God is a “person” or “personal.”
B. Three distinct Persons in one Nature
Nevertheless, there are three distinct persons ( hypostases ) identical with the one divine nature ( ousia ). Because the divine nature is identical with its existence ( esse ), as explained above, there can he only one God. Thus the person of the Father cannot be distinct in any way from the divine nature which is esse , or ipsum esse subsistens ( Sum. theol. I, q.28, a.2). Although none of the three Persons is distinct from the one identical nature or ousia, each is really and truly distinct from the other two, as Father is from Son ( Sum. theol. I, q.28, a.3). The only meaning open to our appreciation of the mystery is to be found in the terms God himself used to reveal himself, namely, the relative terms of “Father,” “Son,” and “Spirit” ( Sum. theol. I, q.29, a.4).
The role of a father is “to beget,” just as the meaning of sonship is “to be begotten.” The Father, therefore, is unbegotten, but is origin and progenitor of the Son, who himself does not beget, for there is no “Son” in the Godhead other than himself. That is to say, the whole reality of the Father is to beget, to generate, to give all that he has, namely, his whole divine nature, to the Son. And the whole reality of the Son is to be begotten, to be generated, to receive all that he has, namely, his whole divine nature, from the Father. This relation of Father and Son within the Trinity is clearly expressed throughout the Gospel of John: “All that the Father has are mine” (Jn 16:15). “Father, glorify your Son, since you have given him authority over all men” (Jn 17:1-2); “The teaching you gave me, I have given to them” (Jn 17:8); and again, “My teaching is not my own, but of him who sent me” (Jn 7:16). Both St. Augustine and St. Thomas wax eloquent on the precision of this expression. Jesus’ doctrine does not belong to himself as originating with him. Rather it belongs to, it is the possession of, the Father (in the genitive case); it is the Father’s doctrine precisely as received from him by the Son. The life of the Father is an eternal giving of himself whole and entire to the Son. The life of the Son is an eternal receiving of the Father whole and entire. The life of the Father and the Son together is an eternal breathing of the Spirit, while the life of the Spirit is an eternal breath, or gift, whole and entire from the Father and the Son together.
It is obvious that the Spirit must proceed from the Father and the Son ( Patre Filioque ), and not from the Father alone, for in the latter case another “son” would be generated and there would be no distinction between the Son and the Spirit, as Catholic faith teaches ( Sum. theol. , I, q.36, a.4; see Sum. contra Gent. , IV, cc. 1 26, Contra errores Graecorum, etc.). The Holy Spirit thus possesses the identical nature of the Father and of the Son precisely as breathed (spirata) by Father and Son. He is the “gift” ( donum ) sent to the Church and into the hearts of all baptized in the Spirit. He is the “uncreated grace” ( gratia increata ) by whom all those with “created grace” ( gratia creata ) live the intimate life of the Godhead. He is the Spirit that Jesus breathed on the disciples that they might have his Spirit. In other words, the Spirit belongs to the Father and the Son, just as the Son belongs to the Father. Just as the Son was sent into the world at a particular period in human history “when the fullness of time had come” (Gal 4:4), so the Holy Spirit was sent in a visible way to men at a special time in human history ( Sum. theol. , I, q.43, a.2 and a.7).
The precise problem where human understanding must give way to belief in a mystery is how can one personal God, who is ipsum esse subsistens and a person, be in fact three distinct Persons and not three gods. If there are three Persons, each “an individual substance of an intellectual nature,” as Boethius and sound philosophy define “person,” then why is not each Person a distinct substance with its own esse? That is to say, why are there not three gods, if there are three distinct Persons? Or rather still, why are there not four persons, a quaternity, as Peter of Poitiers seems to have implied, according to Geoffrey of Auxerre, St. Bernard’s secretary, in his Libellus against the so-called capitula ( PL 185, 598; cf. Sum. theol. , I, q.28, a.2; N. Haring, The Commentaries on Boethius by Gilbert of Poitiers, Toronto: PIMS, 1966, 3-13). To put the question in a less philosophical context, how can one God be three Persons? Or conversely, how can three distinct Persons be only one subsistent esse and not three? At this point no amount of philosophical analysis and explanation can dissolve the real mystery, something transcending mere human intelligence. All we must insist upon is the absolute identity of person and nature in God and we must not think of the “person” as “an adjunct, or something extrinsically attached,” as Gilbert seems to have suggested ( Sum. theol., I, q.28, a.2). Not even when we see God “face to face” and know him as he really is will the mystery dissolve. Only God can comprehend himself. Not even the angels and demons, whose spiritual intelligences far transcend every human intelligence, can understand the mystery.
The importance and sublimity of this mystery of the Trinity becomes more apparent when we prayerfully consider the mystery of the Incarnation: the fact that the Son of God (and only the Son) became true man for our sake, suffered, died, and triumphed over death, that we might have his life. This will be discussed in Note V below.
By way of summary, we can say that the one true God has only one nature, which, of itself, is the total actuality of being (esse), containing no distinctions, potentiality, temporality, or need, having no beginning or end or mutability. This ousia is subsistent truth and love, knowing all things, even what is “future and contingent” to us, and loving all those whom he has freely chosen to love und share in his eternal, dynamic bliss. By faith (and faith alone) we are given a glimpse of the dynamic nature of the Godhead in three distinct Persons: the Father, the Son, and the Holy Spirit. Each Person, though identical with the divine nature, is distinct from the other two by the way in which that nature is possessed. The Father is the divine nature precisely as giving it whole and entire from all eternity to the Son. The Son is that same divine nature precisely as being given it whole and entire from all eternity, himself begotten, but in no way “created.” The Holy Spirit is that same divine nature precisely as breathed by the Father and the Son, himself unbebotten and ungenerated, but simply the Father’s breath of love for the Son and the Son’s breath of love for the Father.
In human history the “Only Begotten Son of the Father” was sent into the world to become man, suffer under Pontius Pilate, die and be raised up again on the third day. Also in human history the Spirit of God, the gift of love, was sent by the Father and the Son into this temporal world to sanctify and to animate the “people of God” in their pilgrimage to their true home, which is eternal bliss with all the saints in seeing God face to face. “Then I shall know even as I am known” (1 Cor 13:12).
In the prologue to his Contra errores Graecorum St. Thomas manifests a fine sense of history, as well as the demands of a good translator. He notes that the writings of our ancient holy Fathers must be seen in their historical context. That is, before the Arian heresy concerning the precise relationship between the person of Jesus and the person of God, ecclesiastical teachers were not as precise in speaking about the unity of the divine essence as were teachers after Arius. Similarly, even St. Augustine, one of the great doctors of the Church, was not as precise about grace and free will when he was writing against the Manicheans in his youth as he was in the face of the heresy of Pelagianism. Thus in his later writings, particularly in his anti-Pelagian works, Augustine speaks most cautiously about man’s free will and the primacy of God’s free gift of grace and final perseverance. And so, St. Thomas says, it is not surprising if modern doctors of the faith, coming after so many new errors, speak more cautiously and more elaborately concerning the doctrine of faith, so as to avoid all heresies. Hence if some things are found in the writings of the ancient doctors that are not as cautiously expressed as the moderns would like, those writings are not for that reason to be disdained or cast aside. Nor should those statements be expanded but reverently explained.
Coming to the main point in his prologue, St. Thomas notes with sympathy the problems of the translator. What might sound good in Greek may not always sound correct in Latin. For this reason the Latins and Greeks profess the same truth of faith in different words. An important example is the mystery of the Trinity itself. For among the Greeks it is correct and orthodox to say that the Father, the Son, and the Holy Spirit are three hypostases. But among the Latins it would not be correct to say that they are three substances, even though hypostasis for the Greeks is the same as substantia for the Latins in literal translation. For among the Latins the term substantia is more commonly taken to mean the essence, which both the Greeks and the Latins admit to be only one in God. For this reason, just as the Greeks say there are three hypostases, we say there are three persons, as even St. Augustine acknowledges in his De trinitate (VII, n.7, PL 42, 939).