Belief in the Trinity is central and crucial to our Catholic faith. Since it is so important, we should try to achieve a better understanding of it.

What the Church believes and proclaims is that in God there are three distinct Persons -- Father, Son and Holy Spirit. Each of the three Persons possesses the one same divine essence or being. So we can say that there is one God in three distinct Persons.

The terms "essence, nature, substance" refer to the divine "being," which is the same for the Father, the Son and the Holy Spirit. The word "Person" refers to the three owners or bearers of the divine being. Thus, what is one in God is the divine being, while what is three in God is the divine Persons. You will note that we are not contradicting ourselves by saying that one is three, since "one" refers to the substance of God, while "three" refers to the Persons. In a future lecture I will give a more detailed explanation of the precise meaning of these theological terms.

For now let it suffice to say that we Catholics believe in the Most Holy Trinity, that is, we believe that there are three Persons in only one God. This profound truth was hinted at in the Old Testament and clearly revealed by Jesus in the New Testament. Before his Ascension into heaven, Jesus sent out his disciples into the whole world and told them to baptize all nations "in the name of the Father, and of the Son, and of the Holy Spirit" (Matt. 28:19). The oldest doctrinal formulation of the Church's belief in the Trinity is the Apostles' Creed which served as the basis of catechetical instruction and as a baptismal confession of faith since the second century. It is based on the Trinitarian formula of Baptism which was just quoted.

The best guide to the Church's belief in the Trinity is found in the Creed. In addition to the Apostles' Creed, there is also the Creed that we say together at each Sunday Mass. This Creed comes from the fourth century and is an excellent summary of our faith: "We believe in one God, the Father, the Almighty, maker of heaven and earth... We believe in one Lord, Jesus Christ, the only Son of God, eternally begotten of the Father, God from God, light from Light, true God from true God, begotten, not made, one in being with the Father....We believe in the Holy Spirit, the Lord, the giver of life, who proceeds from the Father and the Son." This profession of faith proclaims that there is only one God, but also that there are three Persons in the one God.

According to Catholic belief, God is both one and three. If we ask, "What is one in God?", the answer is that he is one in being or substance. If we ask, "What is three in God?", the answer is that there are three "Persons" subsisting in one God.

Some Christian thinkers of the past, confusing what is meant by substance and person, have held that the three divine Persons are distinct individuals like three human beings; thus, they concluded that there are really three gods who work together in some sort of moral unity. Many contemporary Christians apparently have similar views about God. This opinion has often been condemned by Church Councils of the past.

Others have held that God is one Person and one Being, only that he is given three different names in Scripture. These thinkers said that the names, "Father, Son, Holy Spirit," refer to just one Person in the Godhead, namely, the Father. Thus, in their view, the names "Jesus" and "Holy Spirit" are merely other ways of speaking of God the Father. This view has also been condemned as heretical often by the Church. If it were true, it would mean that the Father is Jesus and that the Father died on the Cross on Calvary -- this heresy is called "Patripassionism"; it would mean that the Father did not send his Son to redeem us, but "sent" himself; it would make many of Jesus' statement about the Father and the Holy Spirit either false or unintelligible, such as that he was sent by the Father.

The Fourth Lateran Council in 1215 enunciated the Catholic belief in the Trinity very clearly:

"We firmly believe and profess without qualification that there is only one true God, eternal, immense, unchangeable, incomprehensible, omnipotent, and indescribable, the Father, the Son, and the Holy Spirit: three persons but one essence and a substance or nature that is wholly simple. The Father is from no one; the Son is from the Father only; and the Holy Spirit is from both the Father and the Son equally. God has no beginning; he always is and always will be; the Father is the progenitor, the Son is the begotten, the Holy Spirit is proceeding; they are all one substance, equally great, equally all-powerful, equally eternal; they are the one and only principle of all things -- Creator of all things visible and invisible."

Some of these words and phrases are difficult to understand for one who is not familiar with the teaching on the Trinity. As we proceed I will explain them one by one.

MAGISTERIUM:

Evidence for the early Church's belief in the Trinity is found in the first creeds as listed at the end of Lesson One.

HOLY SCRIPTURE:

OLD TESTAMENT: There are hints and suggestions of the reality of the Trinity in the OT.

Look up the following: Gen. 1:26; 3:22; 11:7; Isa. 6:3; 11:2; 61:1- 2; Joel 2:28 (quoted in Luke 4:17 and Acts 2:16ff.); Wis. 9:1-17; Pss. 2:7; 33:6; 110:1; Prov. 8:22-25; Sirach 24:5ff.

NEW TESTAMENT: There are over 40 texts in the NT which mention the three Persons in the Trinity. The main ones are:

-- Matt. 28:19, "...make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit..." In the original Greek the three names are all listed in the same way, indicating equality; so the Son and the Holy Spirit are put on the same level as the Father.

-- Matt. 3:16-17, "And when Jesus had been baptized, just as he came up from the water, suddenly the heavens were opened to him and he saw the Spirit of God descending like a dove and alighting on him. And a voice from heaven said, 'This is my Son, the Beloved, with whom I am well pleased.'" The three Persons are all mentioned in this same passage.

-- 2 Cor. 13:13, "The grace of the Lord Jesus Christ, the love of God, and the communion of the Holy Spirit be with all of you." This verse is used at the beginning of the Novus Ordo Mass and gives expression to the Trinitarian faith.

Reading Assignment

Read what the commentaries have to say about these texts from the OT and NT in reference to the Trinity. You should consult the NEW JEROME BIBLICAL COMMENTARY; and the recently published and excellent INTERNATIONAL BIBLE COMMENTARY edited by Wm. Farmer and published by The Liturgical Press, in Collegeville, Minn. (1998).

Writing Assignment

Write an essay of two or three pages, based on early witnesses, showing that the Church professed belief in three Persons in one God, beginning with the New Testament.

Suggestion

Read Book II of St. Augustine's De Trinitate (On the Holy Trinity).

God's revelation to man about himself and his own inner life proceeded in stages. There is a steady progression through the OT until the fullness of revelation is made by Jesus, the only-begotten Son of the Father, in the NT.

As we mentioned in the last lecture, there are some hints about the inner trinitarian life of God in the OT; a good example of that is Gen. 1:26. This is most likely what is called the magisterial "we", such as the Popes used to employ and still do on occasions, but still many of the Fathers of the Church considered it a hint of multiplicity in the Godhead.

In the wisdom books, especially Proverbs 8 and Wisdom 7 & 8, divine wisdom is personified; it has proceeded from God from all eternity and cooperates in the creation of the world. In the light of the full revelation of the NT, one may well see in these passages a pointer to the divine personality of the Word of God who is the image of the Father or wisdom.

The OT frequently mentions the "spirit of God." What is meant is not a divine Person but a power proceeding from God which gives life, bestows strength and illuminates the mind. In the light of the NT many of these passages (see Ps. 104:30; Isa. 11:2; Wis. 1:7) were referred by the liturgy and the Fathers of the Church to the Person of the Holy Spirit:

-- Ps. 104:30, "When thou sendest forth they Spirit, they are created; and thou renewest the face of the ground."

-- Isa. 11:2, "The spirit of the Lord shall rest on him, the spirit of wisdom and understanding, the spirit of counsel and might, the spirit of knowledge and the fear of the Lord."

-- Wis. 1:7, " Because the spirit of the Lord has filled the world, and that which holds all things together knows what is said..."

In human language the word "father" designates a relationship that exists between a man and his offspring. A father is one who has begotten a child; he is an originator, a transmitter or a source of life. The term can be used in its proper sense of the relationship of father to son or daughter; it can also be used in an improper, derived or metaphorical sense of someone who causes or produces something else. Thus, inventors are often called the fathers of their inventions.

The OT often speaks of the fatherhood of God in the metaphorical sense. For example, we read in Deuteronomy 32:6, "Is this the return you make to Yahweh? O foolish, unwise people! Is not this your father, who gave you being, who made you, by whom you subsist?" God is the "father" of created things, especially of man, by reason of his creation, preservation in being and providence. Through our redemption and elevation to the state of grace, God is our Father in the spiritual and supernatural order. Thus, Jesus says, "your light must shine in the sight of men, so that, seeing your good works, they may give praise to your Father in heaven" (Matt. 5:16). And again, "you must therefore be perfect just as your heavenly Father is perfect" (Matt. 5:48).

God is our Father, yes, but not in the proper sense of generating us so that we are of the same nature as he. In that sense, God has only one Son, the eternally only-begotten Son who is Jesus, our Lord and Savior.

NT revelation teaches that there is in God a fatherhood in the proper sense which belongs to the first person only. Jesus' relation to the Father is unique and exclusive. When he speaks of the Father in heaven he says either "my Father" or "your Father," but never "our Father," including himself with his disciples. The reason is that his relationship to the Father is very different from that of the disciples or of us. When Jesus teaches the disciples to pray the "Our Father," he tells them how to talk to God. but this is not Jesus' prayer for himself; when he prays he says simply "Father" or "my Father."

Other statements of Jesus, which assert his identity with the Father, prove also that his sonship and the fatherhood of God are to be understood in the proper sense of originator or principle. This identity is brought out in terms of knowledge in the important passage in Matt. 11:27, "Everything has been entrusted to me by my Father; and no one knows the Son except the Father, just as no one know the Father except the Son and those to whom the Son chooses to reveal him." The same idea is expressed even more clearly in John 10:30, "I and the Father are one," and in John 5:26, "For the Father, who is the source of life, has made the Son the source of life."

St. John calls Jesus the only-begotten Son of God, "And we saw his glory, the glory as it were of the only-begotten of the Father" (1:14). St. Paul says that "God did not spare his own Son" (Rom. 8:32). Jesus' enemies clearly understood that he claimed equality with God because God is his Father; for this reason they plotted to put him to death. St. John says that the Jews were "even more intent on killing him, because, not content with breaking the sabbath, he spoke of God as his own Father, and so made himself God's equal" (5:18). In this context, it should be noted that the word "God" (in Greek; ho theos) in the NT almost always refers to the Father; there are a few cases in which the Son is called God and also the Holy Spirit, but they are rare.

Since Jesus is the Son of the Father, he has the same divine nature that the Father has. So he is equal to the Father in all things except to be Father. Thus, the Father communicated his whole substance to the Son -- everything he is except his paternity of the Son. From this it follows that the Son is divine -- he is God Almighty. He is also a distinct Person, different from the Father; not separate from the Father, but distinct from the Father. For many times Jesus says in the Gospels that he was sent by the Father into the world; he says that he came to do the will of his heavenly Father. These expressions indicate a distinction between the Father and the Son. They are not just synonyms for the same Person, as the modalists or Sabellians would have it.

We read at the very beginning of St. John's Gospel: "In the beginning was the Word, and the Word was with God, and the Word was God. He was in the beginning with God; all things were made through him, and without him was not made anything that was made." St. John goes on in the same chapter to identify the Word with Jesus of Nazareth. This text points out that the Word is God and that he is a distinct Person, different from the Father, for "he was with God."

Consider what the Athanasian Creed (D 39-40) (also known as the "Quicumque" from the first Latin word) says:

"We worship one God in the Trinity and the Trinity in unity; we distinguish among the persons, but we do not divide the substance. For the Father is a distinct person; the Son is a distinct person; and the Holy Spirit is a distinct person. Still, the Father and the Son and the Holy Spirit have one divinity, equal glory, and coeternal majesty. What the Father is, the Son is, and the Holy Spirit is....Thus, the Father is God, the Son is God, and the Holy Spirit is God. But there are not three gods, but one God... The Father is not made by anyone, nor created by anyone, nor generated by anyone. The Son is not made nor created, but he is generated by the Father alone. The Holy Spirit is not made nor created nor generated, but proceeds from the Father and the Son."

For Scripture references on God the Father consult the texts cited at the end of Lessons 1 and 2.

Reading Assignment

Read what St. Thomas Aquinas says on this in the Summa Theologica, I, QQ. 31, 32 & 33.

Writing Assignment

Write an essay of two or three pages on God the Father, using the Scriptures, the early creeds of the Church, and the liturgy of the Church.

We have just considered the fatherhood of God in the previous lecture. For most of us it is not difficult to think of God the Father in personal terms. Over the centuries a number of heresies have denied or questioned that the Son and the Holy Spirit are distinct Persons who are not identified with the Father. Others have asserted that they are indeed distinct persons, but that they are not divine Persons. According to these heretics, the Son and the Holy Spirit are creatures of the Father. So there was a time when they did not exist -- they are not eternal.

What do you think about this? Are the Son (Jesus) and the Holy Spirit really divine Persons, distinct from the Father, but subsisting in the same divine essence? Are you able to pray convincingly to all three Persons -- Father, Son and Holy Spirit, and to be always aware that you are praying to the one God?

What is the teaching of the Catholic Church on this matter? The Church teaches that there are three Persons in one God. This means that the Son and the Holy Spirit are Persons distinct from the Father, but that they are God just as he is God, since they are united in the same divine essence or being. In order to illustrate this, St. Patrick used a shamrock as a simple model -- it is one leaf with three protrusions; the same idea is also expressed by a triangle -- one figure with three points.

For scriptural confirmation of this belief we turn first to St. John's Gospel. In the Prologue (1:1-18), John writes about the Word of God: "In the beginning was the Word: the Word was with God and the Word was God." According to John, the Word is not an attribute or power of God; the Word is a Person. This is indicated by stating that "the Word was with God." He also says that the Word "came to his own domain" (v. 11) and that "the Word became flesh." Both of these expressions can refer only to a Person, not to some divine attribute.

The Word is not only God, but is also a different Person from God the Father. This follows from the fact that the Word was "with God," and also from the identification of the Word with the only-begotten Son of the Father in verse 14: "We saw his glory, the glory that is his as the only Son of the Father."

John also says, "And the Word was God." This means that the Word is divine. The true deity of the Word is also implied by certain divine attributes given to him. John ascribes creation to him: "Through him all things came to be" (v. 3), and eternity: "In the beginning was the Word." In addition to St. John's Prologue, many other passages from the Bible could be cited to prove the personality and divinity of the Son of God, who is Jesus the Lord.

It is also an essential part of Catholic belief that the Holy Spirit is a real Person and not just another name for some of the activities of God the Father. This is shown by the Trinitarian formula of Baptism, "...in the name of the Father, and of the Son and of the Holy Spirit" (Matt. 28:19). In this very important text the Holy Spirit is ranked on the same level with the Father and the Son. The Holy Spirit is also given the personal title of "Paraclete," which means helper, or representative or advocate (John 14:16, 26; 15:26). In addition, personal qualities are ascribed to the Holy Spirit, such as teaching the truth (John 16:13) and installing bishops (Acts 20:28).

The Holy Spirit is not just a real divine Person; he is also distinct from the Father and the Son. This is proved by the Trinitarian formula of Baptism cited above. It is also indicated by the appearance of the Holy Spirit at the Baptism of Jesus in the Jordan under the special symbol of a dove (Matt. 3:16-17). Moreover, in his discourse at the Last Supper Jesus distinguishes between the Holy Spirit, as one who is sent, and the Father and the Son who send him (John 14:16, 26; 15:26).

The Holy Spirit is also a divine Person, co-equal with God the Father and God the Son. For proof of this we again turn to the Trinitarian formula of Baptism in which the Holy Spirit is mentioned as equal to the Father and to the Son who are truly God. Another proof of the divinity of the Holy Spirit is the fact that the NT ascribed divine attributes to him. The Holy Spirit, according to Scripture, possesses the fullness of knowledge: he teaches all truth (John 16:13) and searches the innermost secrets of God (1 Cor. 2:10). The divine power of the Holy Spirit is revealed in the Incarnation of the Son of God (Luke 1:35; Matt. 1:20) and in the miracle of Pentecost (Acts 2:2-4).

The biblical teaching of three Persons in one God can be reconciled with the same biblical doctrine of the oneness of the divine nature only if the three divine Persons subsist in one single nature or being. The numerical unity of the divine being is indicated in the Trinitarian formulas (esp. Matt. 28:19). Jesus explicitly declared the numerical unity of his divine nature with that of the Father when he said in John 10:30, "The Father and I are one." The same idea is expressed in John 14:9 when Jesus says to Philip, "He who has seen me has seen the Father."

In order to express the numerical unity of the essence of God, the Church says that the Son and the Holy Spirit are "one in being with the Father" or "consubstantial with the Father." The Greek word for this idea is "homoousion" which means "having the same substance." What the Father is in divinity, that is what the Son and the Holy Spirit are also. This expression was made normative and a test of orthodoxy for all time by the First Council of Nicaea in 325.

A final word. I realize that some of the ideas and expression connected with the Catholic doctrine of the Holy Trinity are difficult to understand the first time you hear them. A careful study of the early creeds mentioned previously will help in this regard.

The biblical texts cited in this lesson are all important and should be studied carefully in order to attain a better understanding of the distinctness of the three Persons in the Trinity, their divinity, and their consubstantiality. The most important ones are:

-- Matt. 28:19 = mission to baptize

-- Matt. 3:16-17 = theophany at the Baptism of Jesus in the Jordan river

-- John 14:16, 26; 15:26 = the sending of the Holy Spirit

-- 1 Cor. 12:4-6 = distribution of charisms attributed to all three Persons

-- 2 Cor. 13:13 = invocation of the three Persons

Reading Assignment

Read the article on the Holy Trinity in the New Catholic Encyclopedia (1967), Vol. 14; or in the original Catholic Encyclopedia (1909). 

St. Thomas Aquinas, Summa Theologica I, QQ. 34, 35 and 36.

Writing Assignment

Write a three page essay giving the theological evidence from Holy Scripture and from the Magisterium of the Church that the Son and the Holy Spirit are distinct Persons and that they are divine.

Suggestion

Read Book III of St. Augustine's De Trinitate (On the Holy Trinity). 

Some rationalists and modernists in the late 19th and early 20th centuries claimed that there is no convincing proof of belief in the Trinity among Christians until the beginning of the fourth century. So our next step is to consider some of the evidence from the first three centuries that proves the Church always believed in the Trinity, even though some of their expressions are different from what came later in the major Councils of the Church. In this lecture we will show that the trinity of persons in the unity of the divine essence is certain from the constant tradition of the Church before the Council of Nicaea in 325 A.D. The witnesses during this period are often referred to as the Pre- or Ante-Nicene Fathers.

At the Council of Nicaea in 325 A.D. Arianism was condemned. You will recall that Arius said that the Word was the first creature of the Father and so was not really divine. A creed was proclaimed in which what pertains to the consubstantiality of the Son and to his generation from the substance of the Father was added to the ancient creeds (see D 54 for the Nicene Creed). With that the trinitarian doctrine was protected against the errors of subordination and other errors opposed to orthodoxy. At that time there was no controversy about the Holy Spirit, and having established the true divinity of the Son, there was no problem about admitting the divinity of the Holy Spirit. When Macedonianism appeared about the middle of the fourth century (which denies the divinity of the Holy Spirit), it was firmly rejected at Constantinople I in 381. Here we are mainly concerned with the tradition of the first three centuries.

Catholics hold that from the very beginning the Church always believed in the Holy Trinity according to its essential elements, namely, there is one God, Father, Son and Holy Spirit, in three distinct Persons.

How do we establish this position? The first argument is from the condemnation of Arianism at Nicaea. Arianism was looked upon as a new blasphemy and caused much commotion. This in itself is an indication that it was opposed to the traditional belief. At Nicaea the Fathers added to the original profession of faith the idea of consubstantiality and they also said that the Son is generated "from the substance of the Father" (Latin: ex substantia Patris). With these additions the true divinity of the Son was asserted along with his procession from the Father as a true generation; it also affirmed the unity of the divinity as shared by both Father and Son without any division of the substance. By these words all the suggestions of the Arians re ditheism, modalism and division in the divine substance were excluded.

Other testimonies of the common faith are shown in the following ways: a) in the baptismal liturgy which used the formula "in the name of the Father and of the Son and of the Holy Spirit," and from the triple immersion at Baptism as witnessed by the Didache, St. Justin and St. Irenaeus. b) In prayer which is normally directed to the Father, but always along with the Son and the Holy Spirit. c) In the doxologies, "Glory be to the Father, and to the Son and to the Holy Spirit."

Our thesis is proved from the authority of the Church in condemning the heretics. Thus, the Roman Pontiffs Saints Victor, Zephyrinus and Callistus condemned the Monarchianists and the Sabellians. Pope St. Dionysius (ca. 260 A.D.) condemned all the anti-trinitarian errors in his letter which can be found in Denzinger D 48-51.

Most of the Pre-Nicene writers are witnesses to the trinitarian faith. They firmly hold for the unicity of God, and the distinction of Persons, which they derive from the two processions (which we will take up in the next lecture). They rejected the main points of Arianism even before it was proclaimed. For example, St. Clement of Rome (ca. 95 A.D.) said: "God lives and the Lord Jesus lives, and the Holy Spirit, who are the faith and hope of the elect." (This can be found in William A. Jurgens, The Faith of the Early Fathers, Vol. I, The Liturgical press, 1979; under R 28.)

The statements of some of the Ante-Nicene writers, which can be and have been interpreted in various ways, do not negate the universal tradition of the Church with regard to faith in the Trinity. These difficulties are of two kinds:

1) In several writers there are expressions which seem to favor subordinationism; the Arians and Semi-Arians made great use of them. For example, they say the Father is superior to the Son and the Holy Spirit, who are in the 2nd and 3rd place; Origen calls the Son "the Second God"; the generation of the Son is said to be voluntary rather than necessary and eternal; Origen and Theophilus of Antioch said that the Son served the Father in creation and did his will.

2) When they explain the dogma they use theories which seem to be tainted with subordinationism and modalism: a) they explain the generation of the Son in reference to the creation of the world (Theophilus & Tertullian); b) they attribute the theophanies in the OT to the Son, because the Father is invisible by reason of his immensity, but the Son is visible according to the operation proper to him; c) Origen seems not to give full simplicity to the Son because he contains the ideas of things to be created; the Son has less knowledge than the Father; he limits the operations of the Son and the Holy Spirit; he says one should pray only to the Father (see his De Principiis 1, 35).

Catholic authors are divided on the interpretation of these statements and theories of the Ante-Nicene Fathers. Here are a few of their responses.

To 1) The Faith of the early Church did not depend on the authors cited. Some of them were at some point heretics or schismatics. There were doubts about their doctrine during their lives, v.g., Tatian, Tertullian, Hippolytus, Novatian, and perhaps Origen. There was always a basic understanding of this important doctrine of the Trinity according to its essentials, i.e., the unicity of God, three really distinct Persons and their equal divinity.

To 2) The doubtful modes of expression of these authors can be given an orthodox interpretation. Thus, putting the Word in the second place can be merely a way of speaking about the three Persons; that the Father is superior to the Son can refer to his priority or origin; Origen's "second God" can mean the 2nd one having divinity; that the Word serves the Father in creation is a metaphor used also by St. Irenaeus.

So the statements of the apologists of the 2nd century and the theologians of the 3rd century, even though they sound like the gentile syncretists, are really very different in content and can be given an orthodox interpretation.

Reading Assignment

In a theological dictionary or encyclopedia read the articles on the following Ante-Nicene writers: St. Justin Martyr, St. Irenaeus, St. Clement of Alexandria, Tertullian, Origen.

Writing Assignment

Write paper of two to three pages on one of the men mentioned above, or on the Council of Nicaea, the first ecumenical Council in 325 A.D.

Suggestion

Read Book V of St. Augustine's De Trinitate. 

As we have seen, we know from the NT, from the early creeds and from the teaching of the Church that there are three Persons in one God -- Father, Son and Holy Spirit. Two questions that naturally occur to a Christian who begins to reflect on the mystery of the Holy Trinity are: 1) Where did the three Persons come from? and 2) How are the three related to each other? The answers to these questions are not easy.

The first question touches on the origin of the three Persons. According to the Bible, the Father is the source or the originator or the first principle of all things. Absolutely everything outside of God, that is, the world and the universe and all finite things were created by the Father. We profess our belief in that every Sunday when we pray the Nicene-Constantinople Creed. But what about the internal divine life? Can we say that the Father created the Son and the Holy Spirit? No, we cannot say that, for we have already seen in a previous lecture that the Son and the Holy Spirit are co-equal to the Father in divinity.

If the Father did not create the Son and the Holy Spirit, then where did they come from? The answer to this most difficult question is to be sought in Holy Scripture, Tradition and the faith of the Church. The Church teaches in this matter that in God there are two internal divine processions. By "procession" is meant the origin of one from another. A procession in this sense can be either external or internal, depending on whether the term of the procession goes outside the principle from which it proceeds or remains within it. Thus, creatures proceed from God by external procession, but the Son and the Holy Spirit proceed by an immanent act of the Most Holy Trinity, since they belong to the internal life of God. An "internal divine procession," therefore, refers to the origin of one divine Person from another through the communication of the numerically one divine essence.

The Catholic Creeds teach us that there are two internal divine processions: the generation of the Son and the procession of the Holy Spirit (which, we shall see, is called "spiration"). Consider, for example, what we profess in the Creed at Sunday Mass: "We believe in one Lord, Jesus Christ, the only Son of God, eternally begotten of the Father"; and "We believe in the Holy Spirit...who proceeds from the Father and the Son." What does this mean? It means that from all eternity the Father generates the Son, and the Father along with the Son "breathes forth" the Holy Spirit. Thus there are two internal divine processions which give rise to three divine Persons.

Why is the word "procession" (= "coming forth") used for the internal divine activity? The reason is that Jesus himself used this expression according to St. John's Gospel. Thus in 8:42 Jesus says, "I proceeded from God." In 15:26 he says that he is going to send to the Church the Holy Spirit,"the Spirit of Truth who proceeds from the Father." Accordingly, we learn from these and similar passages that there are two internal processions in God.

It is a dogma of the Catholic faith that the second divine Person proceeds from the first divine Person by an act of generation and therefore is related to him as Son to Father. The Nicene Creed says that Jesus Christ is "the only-begotten Son of God, born of the Father before all time." The Athanasian Creed of the fifth-sixth century says: "The Son is not made or created, but he is generated by the Father alone."

According to the NT the first and second Persons stand to each other in relationship of a true fatherhood and sonship. The characteristic biblical name for the first Person is "Father," while that of the second Person is "Son." Jesus refers to the Father as "my own Father" (John 5:18),"He called God his own Father, making himself equal with God." Jesus is spoken of as God's "own Son" (Rom. 8:32), as "the only Son of the Father" (John 1:14), as "my beloved Son" (Matt. 3:17). Thus God's only-begotten Son is distinguished from the adopted children of God, which is what we are. Jesus, however, according to Scripture, is the natural Son of God. The eternal generation of the Son from the Father is clearly expressed in Psalm 2:7 and Hebrews 1:5, "You are my Son, this day I have begotten you."

The correct understanding of "generation" here is most important. The theologians define it as the origin of a living being from a living principle of the same nature.

From the Creed at Mass we know that the Holy Spirit "proceeds from the Father and the Son." The Athanasian Creed states: "The Holy Spirit is not made nor created nor generated, but proceeds from the Father and the Son." It is also a matter of Catholic faith that the Holy Spirit proceeds from the Father and the Son "as from one principle." Thus, there are not two principles of the Holy Spirit, but only one. The Second Council of Lyons in 1274 proclaimed as part of Catholic faith: "We confess that the Holy Spirit proceeds eternally from the Father and the Son, not as from two principles, but as from one."

By divine revelation and the explicit teaching of the Church, therefore, we know that in the inner life of God there are two processions and three divine Persons.

Reading Assignment

In order to understand the Church's teaching on the Trinity it is absolutely necessary to know what she says about the two processions in God. So read what St. Thomas says in the Summa Theologica I, Q. 27, a. 1-5.

Writing Assignment

In an essay of about 1000 words explain the two processions in God and show how the concept of "procession" is based on the Scriptures.

Suggestion

Read the articles in one or two Catholic Encyclopedias on the two divine processions.

It is clear from the NT and from the Creed of the Church that the first Person in the Trinity is the Father, and that the second Person is the Son. Since God is pure spirit, that is, since he does not have a body, lacks all composition and potency and is completely independent of matter, it should be obvious that there is no sexuality in God. But if there is no sex in God, we might ask, then why are the first two Persons in the Trinity called "Father" and "Son"? Among human beings, the father-son relationship is based on the sexual act of procreation.

The first two Persons are called "Father" and "Son" because there is a generative activity in God which has some similarities to generation among human being and animals. "Generation" is defined as the origin of a living being from another living being, both having the same nature. Thus, oak trees produce oak trees, monkeys produce monkeys, and men produce men. You will note that the relationship in these examples is between material beings. But in all true generation there is a similarity in nature between the origin or source and what is produced.

In the preceding lecture we considered the two "processions" in God -- that of the Son and that of the Holy Spirit. At present we will confine our attention to the procession of the Son from the Father. We said that the Father "generates" the Son. How does the Father generate the Son if there is no sex in God? The Church, aided by her best theologians, teaches that the Father generates the Son by an act of intellect. I know that this is a hard point to grasp, so I will try my best to explain simply and clearly what is meant.

We all know that Jesus -- the Son of God, the second Person of the Blessed Trinity -- is called the "Word" in the NT. For example, we read in John 1:1, "In the beginning was the Word, and the Word was with God, and the Word was God." Now a word is produced only by an intellect or mind. The external word, whether vocal or written, is a symbol of an idea in the mind, or what is called a "mental word." If there were no mental word, there would be no vocal word. Thus, animals utter grunts, groans, cries, and so forth, but they do not produce words. The reason is that, since they do not have a mind or intellect, they cannot produce an internal idea to which the word refers.

We have already seen that there are two processions in God. In a spiritual being like God there are only two internal activities -- knowing and willing. If there is to be a difference between the two processions, and there is, then one must be according to intellect and the other according to will. Basing its teaching on the Bible and Tradition, the Church says that the Son is generated by the Father by an act of intellect.

It is possible to use the word "generation" for this activity because generation means the production of one living being from another, both having the same nature. Intellectual activity is similar to sexual generation because the mind produces an idea which is the image or representation of the thing known. Thus, in order to know an oak tree some representation of the oak tree must be in my mind; if it were not, then I could not know an oak tree.

As we know, God is absolutely simple -- he has no parts, no composition. This means that he is identified with his knowing and willing. God therefore knows himself perfectly, that is, he has a perfect idea or image of himself. That perfect idea or image is the second Person of the Blessed Trinity. He has the same nature as the Father and is equal to the Father. On this point the Roman Catechism (III,9) teaches: "For just as our spirit, knowing itself, produces a picture of itself which theologians have called a 'word,' so God also, insofar as the human can be compared with the divine, knowing himself, generates the Eternal Word. Thus the generation of the Son from the Father is to be conceived purely as an intellectual generation or as an act of intellect."

Generation and intellection both involve likeness. Since the Son of God is the perfect image of the Father, we are entitled to say that he is generated by an act of intellect. In the NT the second Person of the Trinity is called the "Word of God" (see John 1:1ff). Since a word is produced by an intellect, this name indicates that the Son is the product of the knowledge of the Father.

In the NT the Son of God is called the Word. You will find that in John 1; Rev. 19:13; 1 John 1. The Fathers of the Church developed this notion and it is found in the definition of the Council of Chalcedon in 451 (D 148). The argument here runs like this: The Word is a proper name of the Son of God in the NT. But by the name "word" is signified something pertaining to the order of intellect and having its origin through intellect. Therefore, the procession of the Word is through or by intellect.

The second Person is also called "the wisdom of God" in the Bible (see 1 Cor. 1:24). The personal name "Wisdom" indicates that the Son is generated by an act of cognition of the Father. If the Son proceeds from the Father by an act of intellect, then we can see why he is presented in the wisdom books of the OT as being born and personified (see Wis. 8; Prov. 8; Sir. 24). Since all three divine Persons are wise -- are substantial wisdom, the reason why the Son is called "Wisdom" is that by this name his way of origin is signified, for the source of wisdom is the intellect.

The expressions "image of the invisible God" (Col. 1:15) and "perfect copy of the substance of God" (Heb. 1:3) indicate that the generation of the Son takes place through that activity of the Father which tends to produce a likeness of himself, namely, through the activity of knowing. For an image of something must be similar to its source; it is intellect which produces the Word which is an image of the Father. (On this see S. Th. I, Q. 35, aa 1-2).

Therefore, since the Bible refers to the Son by using "Word," "Wisdom," and "Image," and since these terms are related to cognition, we are justified in saying that the Father generates the Son by an act of knowledge.

St. Thomas puts the argument briefly in I, Q. 27, a.1: Divine processions must take place according to the immanent operations proper to a spiritual nature. But the first operation of this kind is intellection. Ergo, the first procession in God is by intellect.

For, just as the human mind, when it knows, forms an image of the thing known, because by it the mind speaks with itself in some way, so also in his own way, the Father, when he knows by his infinite intellect, produces a term which is a certain expression of the thing known, which is properly called the "Word."

Thus, the divine Word agrees with the internal human word inasmuch as it is spiritual, permanent, immanent and naturally representing the known object. But the divine Word is very different from the human word: the human word is accidental, the divine is substantial; the created word is very limited, the divine Word is infinite in perfection.

Reading Assignment

St. Thomas Aquinas, Summa Theologica I, QQ. 34 & 35.

Writing Assignment

Write an essay of two to three pages explaining why the Church says that the Father generates the Son by an act of knowing.

Suggestion

St. Augustine, De Trinitate, Book VI.

We have been considering the origin of the Son and the Holy Spirit from the Father. We reflected on the profound truth that the Father generates the Son by an act of intellect. When we know something there is a likeness of it in our mind. So also the Father, knowing himself perfectly, produces a perfect image of himself. That perfect image is the Son of God, the second Person of the Blessed Trinity.

We know by faith -- the Church tells us, the Bible tells us and we profess in our Creed -- that there is a third Person in the Trinity whom we call the Holy Spirit. Today most of us are aware of the activity of the Holy Spirit in our lives and in the life of the Church. Many people now pray regularly to the Holy Spirit. Forty years ago that was not so common. At that time he was often referred to as "the forgotten Person" in the Trinity.

Let's admit it: it is difficult for us to get a mental grasp on the Holy Spirit. We can imagine the Father and the Son, Jesus Christ. How do we imagine the Holy Spirit? About the best we can do is to picture to ourselves a dove descending on Jesus as St. John baptizes him in the Jordan River. Or we might imagine the tongues of fire descending on the Apostles in the upper room on Pentecost. But it is difficult for us to attach the meanings of personality and divinity to a dove or a tongue of fire. The latter, however, are visible signs or symbols of the invisible third Person of the Blessed Trinity

We have already seen that there are two processions or internal activities in God -- knowing and willing. The NT and the Teaching Authority of the Church say that the Son proceeds from the Father by an act of intellect. The Holy Spirit also proceeds from the Father (and the Son) but the NT does not specify precisely how or in what way he proceeds. The common teaching of the great theologians like Augustine and Thomas Aquinas is that the Holy Spirit proceeds from the will or from the mutual love of the Father and the Son. Accordingly, there is a special relationship between the Holy Spirit and acts of the will, especially the act of love which proceeds from the will and not from the intellect.

The Roman Catechism teaches that the Holy Spirit "proceeds from the divine will inflamed, as it were, with love" (I,9.7). The biblical name of the third Person, "Holy Spirit" (pneuma = wind, breath, principle of life), designates a principle of activity. An act of will is an inclination to some known good.

The word "holy" in the personal name of the third Person indicates a relationship to the will, since holiness resides in the will. Also, works of love are attributed to the Holy Spirit. Thus, St. Paul says, "The charity of God is poured forth into our hearts by the Holy Spirit who is given to us" (Rom. 5:5). The attribution of the works of love to the Holy Spirit is based on his origin from the will of the Father and the Son. We infer therefore that the Holy Spirit proceeds from the Father and the Son by an act of love. Thus, the Fathers of the Church, relying on Scripture, call the Holy Spirit: love, charity, gift, living fountain, bond of love, kiss of love. A gift, for example, is directly related to love since a gift is a visible sign of love. Thus, St. Peter uses the word "gift" in his sermon on the first Pentecost: "You will receive the gift of the Holy Spirit" (Acts 2:38). The other titles given to the Holy Spirit also indicate some relationship to an act of the will -- to love in one way or another.

Since the Holy Spirit proceeds by an act of will of the Father and the Son, it should be clear that he does not proceed as a perfect image through generation. So the Holy Spirit is not a Son of God; only the second Person of the Trinity can be called "Son," as we have already explained. For St. John calls him "the only-begotten Son" of the Father. Appropriately, then, the fifth century Athanasian Creed says: "The Holy Spirit is not made nor created nor generated, but proceeds from the Father and the Son."

Theologians have given a name to that type of proceeding, calling it "spiration," from the noun "spirit" which, of course, means "breath." We have a good indication of this in St. John's Gospel in Ch. 20:20-23. After his resurrection when Jesus appeared to his Apostles, St. John says "he breathed on them" (v. 22) and then gave them the power to forgive and to retain sins.

The term "spiration" designates the loving activity between the Father and the Son which results in the term of their love, namely, the Holy Spirit. So they say that the Holy Spirit proceeds from the Father and the Son through spiration. This doctrine was taught clearly by the Second Council of Lyons in 1274.

There are three distinct Persons but only one God. So there is only one divine nature or essence which is common to all three. They are co-equal in power, majesty, wisdom and everything else. The distinction between them is to be found in their origin. The Father has no origin. The Son proceeds from the Father by intellectual generation. The Holy Spirit proceeds from the Father and the Son as from one principle because of their intense mutual love. The Father loves the Son and the Son loves the Father so intensely that their mutual love terminates in the third Person of the Blessed Trinity. Accordingly, we are justified in referring to him as the love of God, the power of God, the Spirit of truth, a river of living water and the kiss of the Father and the Son.

It is a defined dogma of the Catholic Church that the Holy Spirit proceeds from the Father and from the Son as from a single principle through a single spiration. You will find this in Lateran IV (D 428), Lyons II (D 460, 463), and Florence (D 691, 703, 704). That the Holy Spirit is not generated and so not a son is affirmed by the Athanasian Creed (D 39), Toledo XI (D 277), and Lateran IV (D 428).

In the NT the Holy Spirit is said to be the Spirit of the Father and the Spirit of the Son. Therefore he proceeds from both the Father and the Son. He is called the Spirit of the Father in Matt. 3:16; 10:20; Rom. 8:9; 1 Cor 2:12. He is called the Spirit of the Son (or of the Lord or of Jesus) in Acts 5:9; 16:7; 2 Cor. 3:17f; Gal. 4:6; Phil 1:19; Rom 8:9-11. These texts speak about a divine Person, not a mere created gift.

The Church teaches that the Holy Spirit proceeds from both the Father and the Son; this idea is expressed in the Creed by the famous word "filioque." Here is an argument for the notion that the Holy Spirit proceeds from both the Father and the Son as from one principle:

Everything the Father has he communicates to the Son, except being Father (paternity). But it belongs to the Father that the Holy Spirit proceeds from him. Ergo, he also communicates that to the Son. Ergo, the Holy Spirit also proceeds from the Son.

In Scripture the unity of the spirating principle is indicated by the way in which the Holy Spirit is presented as proceeding from the Father and the Son. For, that the Holy Spirit is the Spirit of the Father and the Spirit of the Son is presented as the same thing; likewise, that the Holy Spirit is sent by the Father in the name of the Son and that the Son sends the Holy Spirit. This is shown especially in John 16:15 where, when the reason is given why the Holy Spirit proceeds from the Son, it is said that everything which the Father has belongs also to the Son, including the fact that the Holy Spirit proceeds from the Father.

Rightly, therefore, the Church, along with the Fathers and theologians, understands that the Holy Spirit proceeds from both Persons inasmuch as they are one in being a spirating principle (see D 691, 704).

Reading Assignment

St. Thomas Aquinas, Summa Theologica I, Q. 27, aa. 3-4; QQ. 36, 37, 38.

Writing Assignment

In an essay of two to three pages explain the Catholic doctrine on the origin of the Holy Spirit from the Father and the Son.

Suggestion

St. Augustine, De Trinitate, Book VIII.

We believe that there are three Persons in one God -- Father, Son and Holy Spirit. It is important to recall that there is only one God and that God is absolutely simple, as we saw earlier. Simplicity means that there is no composition of parts. An automobile is composed of parts; but my idea of a car is simple.

If God is absolutely simple -- having no parts or principles or elements whatsoever -- how can there be three Persons in him? How can God be three and one at the same time and still be absolutely simple? Does not the Christian doctrine of the Trinity involve a contradiction?

Obviously three is not one and one is not three. The only way we can get out of this seeming contradiction of three Persons and one God is by showing that "three" is meant in one way, and "one" in another. That is exactly what the Fathers and theologians did centuries ago. By reflecting carefully on Holy Scripture and employing the most advanced philosophical concepts, they came to the conclusion that the "three" in God are Persons and that the "one" in God is the divine essence (= nature or substance).

At this point the theologian must be able to show that the three Persons in one God, while retaining their distinctness in the divinity, are not three separate entities. For, if they were three separate individuals, like three human beings, we would have a multiplicity of beings in the Godhead, and there would be more than one God. Inevitably, we must ask: what constitutes the three Persons? The only suitable answer to this most difficult question is that they are relations within the divinity or Godhead.

We all know what a relation is, but very few are able to explain what it is, because it is one of the most difficult realities to grasp. Members of a family are related. There is a real relation between father and son. The father is related to the son by reason of generating him; the son is related to his father because he was generated by him. Thus, we define a relation as an ordination or reference of one thing to another. In every real relation there are three elements: 1) the subject (father), 2) the term (son), 3) the foundation of the relation (activity of generating). The essence of the relation consists in being ordered to another; in Latin this is called "esse ad" and the foundation is called "esse in."

Please note that a relation always exists in something else -- it is not a new, separate individual. John and Jane get married and have a son. At the birth of their son they are now called "father" and "mother." Why? because a new relationship has entered into their lives by reason of having a son. But they are still John and Jane.

Something similar takes place in God. The two internal divine processions of the Son and the Holy Spirit (which we have already considered) establish in God two pairs of real mutual relationships. Accordingly, there exist in God four real relations: 1) Father to Son, 2) Son to Father, 3) Father and Son to the Holy Spirit, 4) Holy Spirit to Father and Son.

The teaching of the Bible concerning the divine relations is found in the personal names of Father, Son and Holy Spirit. The doctrine was developed by the Fathers of the Church, especially by St. Basil, the Two Gregorys and St. Augustine. St. Gregory Nazianzen said: "Father is not the name of the essence or activity but indicates the relation the Father has to the Son and the Son to the Father." The official teaching of the Church embodies this doctrine of the relations. It was taught by the Eleventh Synod of Toledo, Spain in 675 and defined by the Council of Florence in 1442. Thus the personal names in the Trinity are relative -- Father, Son and Holy Spirit.

From a proper understanding of revelation and its development in the tradition it follows that the mutual relations in God are not just logical, this is, they are not just in our minds; rather, they are real relations in God which exist independently of our thinking about them. Otherwise the Trinity of Persons would be just different names that we give to God -- and that is the condemned heresy of Sabellianism or Modalism. Since there is only one God, and he is absolutely simple, it must follow that the difference between the three Persons cannot be based on the divine essence (which is common to all three), but on the mutual relations of the Persons to one another.

Of the four real internal divine relations, three stand in opposition to one another and, therefore, are really distinct, i.e., fatherhood, sonship and passive spiration (= Holy Spirit). The active spiration stands in opposition to the passive spiration only; it is not opposed to fatherhood and sonship and, therefore, is not really distinct from them. So there are only three really distinct relations in God which constitute the three Persons.

It is very important to remember that the relations in God which constitute the Persons are really identical with the divine nature. Whatever is in God is God. The only difference in God is in the opposition of relations. Thus the Council of Florence officially defined that in God "everything is one where there is no distinction by relative opposition" (Denzinger 703).

That there are real relations of origin internally in God follows from the two processions already considered. For origin or production cannot be conceived without the concept of relation, and without relations between the producer and the produced. The question then arises whether these relative concepts imply some reality in God which is signified by the name of "relation."

Related beings in reality are defined as those whose existence is to be referred to another, that is, to something different from the related subject, for what is related to another is the subject, not immediately the relation itself. Therefore, the philosophers say that related things (as such) are known simultaneously, such as father and son.

In relations we must distinguish between the reality (esse in) and the reference (esse ad). For a relation is thought of as a form inhering in a subject. The fact that it refers to another in some way is added to a subject as it were accidentally. Thus the being of a relation is that it inheres in a subject and in this "relation" agrees with other accidents and so it has some reality (esse in). The concept of relation which distinguishes it from other accidents is that it refers to a term or to some other thing; in this regard it is called a reference (esse ad).

We say that in God there are real relations of origin internally, namely, between the divine Persons; so that subjects, terms and the foundation and whatever else is required for the reality of a relation is found in God independently of the mind's consideration. Such relations are implied in the two processions which we already considered. All Catholics who admit the reality of processions in God consequently hold for the divine relations -- and they hold that they are simply real relations. So the names of the three Persons are relative.

The names in Scripture are relative. Here is what St. Thomas says on this point: "The Father is denominated only from paternity; and the Son only from filiation. Therefore, if no real paternity or filiation existed in God [i.e. relations by which Father and Son are referred to each other], it would follow that God is not really Father or Son, but only in our manner of understanding; and this is the Sabellian heresy" (I, Q. 28, a. 1 sed contra).

The divine Persons cannot be distinguished by absolute perfections, for infinity consists in the summit of perfections by which a being becomes better. On the other hand, there cannot be in God a purely numerical multiplication because it presupposes a limitation in nature, and the infinite is unique in its own order. But the Persons can be distinguished by relative properties; for the being of relation as such does not mean, in adding something new, an intrinsic modification, but only a reference to another. Ergo, in God there are of necessity real relations by which the divine Persons are distinguished because a real relation demands a real distinction between subject and object.

In the next lecture we will analyze the statement made above that there are four real relations in God, but that only three of them are subsistent and so Persons.

Reading Assignment

St. Thomas Aquinas, Summa Theologica I, Q. 28, aa. 1-4.

Writing Assignment

Write an essay of two to three pages on some aspect of the internal divine relations.

Suggestion

Read the two articles on relations in the New Catholic Encyclopedia, Vol. 12: "Relation" on pp. 216-219, and "Relations, Trinitarian" on pp. 219-220. If you do not have access to the NCE, then consult some other Thomistic-oriented theological dictionary.

Most of the prayers in the liturgy of the Church are offered to God the Father, through his Son, Jesus Christ, in the unity of the Holy Spirit. As we have seen in previous lectures, there is only one God, but in God there are three distinct Persons. These remarkable truths about God were revealed to the Apostles by Jesus and eventually were written down in the collection of twenty-seven books that we call the New Testament.

Because of modern psychology, we tend to think of "person" as a center of consciousness -- thinking and willing. That is true, but it does not exhaust the reality of what is meant in theology by a divine Person.

In the last talk we considered the difficult truth that the personal names in the Trinity are relative -- Father, Son and Holy Spirit. Thus, when we say "God" we are referring to the divine essence (nature, substance) which is common to all three Persons. When we say "God the Father" we are referring to a relationship in the divinity which is personal. The same holds for the Son and the Holy Spirit.

According to the famous definition of the sixth century philosopher Boethius, "a person is the individual, incommunicable substance of a rational nature." It is an individual substance that exists completely in itself. Person and nature are related to each other in such a way that the person is the possessor of the nature and the ultimate subject of all being and activity, while the nature is that through which the person is and acts.

If you reflect on yourself for a few moments you will see what I mean. When you say "I think" or "my hand" to what reality do the words "I" and "my" refer? They refer to the owner or possessor of all your activities, namely to YOU or your person.

Through such a reflection we can come to see that there is a distinction between what we mean by "person" and what we mean by "nature." This distinction is now common, but it was discovered by the early Fathers of the Church who tried to get a better understanding of the Blessed Trinity.

As I pointed out previously, in God there are two processions -- thinking and loving -- which give rise to the three mutually opposed relations of fatherhood, sonship and passive spiration: these relations are the three divine Persons.

The fatherhood constitutes the Person of the Father, the sonship constitutes the Person of the Son, and the passive spiration constitutes the Person of the Holy Spirit. But in God "everything is one where there is no distinction by relative opposition." Consequently, even though in God there are three Persons, there is only one consciousness, one thinking and one loving. The three Persons share equally in the internal divine activity because they are all identified with the divine essence. For, if each divine Person possessed his own distinct and different consciousness, there would be three gods, not the one God of Christian revelation. So you will see that in this regard there is an immense difference between a divine Person and a human person.

A person is an individual, incommunicable substance of a rational nature. This definition applies to human beings and angels as well as to God. In God, the internal divine relations are substantial because they are really identical with the divine essence. Because they are mutually opposed, incommunicability belongs to the three relations of fatherhood, sonship and passive spiration (active spiration is common to the Father and the Son). Therefore, only these three relations in God are divine Persons. Thus, St. Thomas Aquinas says that each divine Person is a subsistent, incommunicable, internal divine relation (see Summa Theologica, I, Q. 29, a. 4).

By "subsistent" is meant a reality that exists of itself. Since the three divine personal relations are identified with the divine essence, they are subsistent. They are "incommunicable" in the sense that they are not shared by another.

We have been trying to answer the questions: What are the "three" in God that the New Testament tells us about -- Father, Son and Holy Spirit? Or, How can we talk about them? The Church replies that the three are Persons. The, if one asks: What is a divine Person? The answer is that it is a subsistent relation. That is as far as one can go in trying to penetrate the absolute mystery of the Trinity.

Obviously, it is not necessary to know the theology of the Trinity in order to be saved or to live as a devout Catholic. The heart of the Catholic religion is the love and worship of the Father, through the Son, in the Holy Spirit. Jesus said, "This is eternal life -- to know you, the one true God, and Jesus Christ whom you have sent" (John 17:3). But it can be helpful for many Catholics to know that the Church possesses a highly developed rational explanation of the data of Scripture with regard to the Holy Trinity. For, in having us profess faith in the tri-personal One God, the Church is not asking us to believe in something that is contradictory or opposed to human reason. While the Trinity is an absolute mystery, that is, always beyond our grasp and intellectual reach, it is not opposed to reason.

By a "mystery" is meant something that is hidden, veiled, unknown. In this sense, there are many mysteries of nature, since there are aspects of atoms, molecules and living beings that are not yet known. Thus, science is constantly trying to unravel the "mysteries" of nature. This is not what is meant by mystery in the theological sense since human science by experiments and perseverance can finally unlock the secrets of nature. In other words, natural truths are not beyond the power of human reason.

In Catholic theology a "mystery" of faith is a truth revealed by God which totally surpasses the power of the human mind. Once it has been revealed by God we can know something about it, such as the Holy Trinity, the Incarnation and divine grace, but we could never come to any knowledge of it from our observation or experience. Fr. John A. Hardon, S.J., gives the following definition of mystery in his book Modern Catholic Dictionary (Doubleday, 1980): "MYSTERY. A divinely revealed truth whose very possibility cannot be rationally conceived before it is revealed and, after revelation, whose inner essence cannot be fully understood by the finite mind."

Mysteries in this sense are truths that concern God himself, since he is infinite and absolutely incomprehensible to the created mind. Theologians usually list three mysteries in this category: the Trinity, the Incarnation and divine grace or the supernatural. For, these three have to do with the very being of God. According to Catholic teaching these truths are absolute mysteries. By an absolute mystery is meant a truth that not only surpasses the power of the human intellect in this life, but also will surpass it in the next life in heaven. Thus, it follows that the blessed in heaven do not comprehend the Holy Trinity, that is, they do not fully understand it; for all eternity they can learn more and more about it and never exhaust its knowability. Such a consideration gives a hint of the activity connected with the lives of the saints who see God face to face.

The Catholic Church teaches in Vatican I that "there are two orders of knowledge, distinct not only in origin but also in object. They are distinct in origin, because in one we know by means of natural reason; in the other, by means of divine faith. And they are distinct in object, because in addition to what natural reason can attain, we have proposed to us as objects of belief mysteries that are hidden in God and which, unless divinely revealed, can never be known" (Denzinger 1795).

By natural reason we can come to a knowledge of God as their origin and source (see Rom. 1). But the various perfections of God which are revealed through the contemplation of created things, such as his power, wisdom and goodness, are common the three divine Persons. Therefore, natural reason can know God only in his unity of substance, but not in his trinity of Persons.

Our knowledge of the inner life of God -- the life of Father, Son and Holy Spirit -- must come through revelation by God in history. That took place primarily in Jesus Christ and through his Apostles.

Jesus revealed to us the absolute mysteries of the Holy Trinity, his Incarnation and divine grace. In order to receive this revelation we must be able to understand something about these mysteries. They are revealed to us through human words and human actions. We understand something about them when we accept them in faith, but we do not completely grasp them. In theological language, we do not "comprehend" them because "comprehend" means to understand something completely. By reading the Bible, by prayer and by meditation we can come to a deeper understanding of these mysteries, but we will never exhaust them because they have to do with God himself and he is infinitely exalted above us.

Once we know about the inner life of God we can learn more about it by comparing it with the created things we know. In fact, we have already done that in this series when we considered how the Son proceeds from the Father by way of intellectual generation. But the truth about God always remains obscure because, as St. Paul says, in this life "we walk by faith and not by sight" (2 Cor. 5:6f.).

Finally, it is important to note that the dogma of the Trinity is beyond reason, but not contrary to reason. St. Thomas Aquinas says that human reason of itself cannot show the possibility of the Trinity, but it can show that it is not contradictory, and so it can refute all counter-arguments. The Church in Vatican I said that even though faith is above reason, "yet there can never be any real disagreement between faith and reason, because it is the same God who reveals mysteries and infuses faith and has put the light of reason into the human soul" (Denzinger 1797). Therefore, it is reasonable to believe in the Trinity and to adore the Trinity because God has revealed it "who can neither deceive nor be deceived." So there can be no conflict or disagreement between faith and reason because it is the same God who created the world and reveals mysteries of his own inner life.

Reading Assignment

St. Thomas Aquinas, Summa Theologica I, Q. 29, a. 4; Q. 40, a. 2.

Writing Assignment

Write an essay of two to three pages on one of the following two topics: 

1) Explain why Catholic theology calls the three Persons in the Trinity subsistent divine relations.

2) Explain why the three Persons in one God is not contrary to human reason.

In the last lecture we saw that the three Persons are subsistent relations, that is, relations that are really identified with the divine substance.

When we reflect on our faith it is extremely important to realize that there is only one God, but that in God there are three distinct Persons. There is a question, then, obviously of both unity and multiplicity in God. We must retain both of them.

Many Christians, while verbally professing belief in the Trinity, in reality seem to think of God as just one Person. Thus, in their prayers they "pray to God," but they do not direct their attention to the Father or the Son or the Holy Spirit. When they neglect the three Persons and deal with God as if he were one Person, they are in effect functioning like Moslems or Jews who deny the Trinity. As instructed Catholics, we must be on our guard against this all-too-common tendency.

Another common misunderstanding of the Trinity is based on the multiplicity of the three Persons. Some Catholics think that the three Persons are separate, independent beings. In this view each of the three is thought of as having his own thinking, willing and separate consciousness. In other words, they are considered to be similar to three human persons, but only on a higher level and endowed with "divine" power. That view is false and is equivalent to affirming three gods. For, in God everything is one where there is not opposition of relation. Thus, in him there is only one thinking, one willing and one "consciousness." The three Persons share equally in all the divine actions and operations that are proper to the divine nature.

In order to stress the divine unity the Fathers of the Church emphasized the mutual or reciprocal penetration and indwelling of the three divine Persons in one another. We note among human lovers the drive toward union. Kisses and embraces are manifestations of this drive. The impulse of love towards mutual penetration which we witness among human beings is a faint reflection of the mutual indwelling of the three divine Persons.

St. Thomas Aquinas says that by reason of the undivided divine essence, each Person is in each other Person in the Trinity. Our Lord says in this regard, "I am in the Father and the Father is in me" (John 14:10). He also says, "I and the Father are one" (John 10:30; see also 10:38). The indwelling of the Holy Spirit in the Father and in the Son is indicated in 1 Cor. 2:10, "The Spirit reaches the depths of everything, even the depths of God."

The doctrine of mutual penetration or indwelling of the three divine Persons was officially taught by the Council of Florence in the fifteenth century. The Council Fathers declared: "Because of this unity the Father is entirely in the Son and entirely in the Holy Spirit; the Son is entirely in the Father and entirely in the Holy Spirit; the Holy Spirit is entirely in the Father and entirely in the Son" (Denzinger 704). In theology this mutual indwelling has been called, since the eighth century, "circumincession" which comes from the Latin circumincedere and means "to move around in." The point of the teaching is to stress that the three divine Persons are perfectly one in being, knowing and willing.

I have already mentioned the impulse of love towards union. In the Trinity each divine Person is irresistibly drawn, by the very constitution of his being, to the other two. Branded in the very depths of each one of them is a necessary outward impulse urging him to give himself fully to the other two, to pour himself out into the divine receptacle of the other two. Here we find an unceasing circulation of life and love. Thus, since each Person is necessarily in the other two, unity is achieved because of this irresistible impulse in each Person, which mightily draws them to one another.

In the Beatific Vision the blessed see and taste the divine unity and beauty. In this regard Pope Pius XII said in his letter on the Mystical Body of Christ (#80): "It will be granted to the eyes of the human mind, strengthened by the light of glory, to contemplate the Father, the Son, and the Holy Spirit in an utterly ineffable manner, to assist throughout eternity at the processions of the divine Persons, and to rejoice with a happiness like to that with which the holy and undivided Trinity is happy."

Note that circumincession brings out the perfect equality of the three Persons. In a subtle, implicit way it expresses the whole doctrine of the Trinity -- consubstantiality, processions/origins, the mutual relations and the distinction of Persons.

Another point I want to bring up here is the external activities of the three divine Persons, that is, acts that terminate in creatures outside the Trinity. In this regard the Church, basing herself on the testimony of the Bible and the writings of the Fathers of the Church, teaches that all the external activities of God are common to the three Persons. In other words, no one of the three divine Persons can act separately and independently of the others on the created world that they produced acting as a single principle.

In support of the above let me point out briefly that the Fourth Lateran Council in 1215 said that the three divine Persons are the sole principle of all things. In 1441 the Council of Florence declared that Father, Son and Holy Spirit are not three principles but one principle of all things (D 704).

A careful reading of the Bible will reveal the same truth. For Scripture often attributes the same activity in the created world now to the Father, now to the Son and now to the Holy Spirit. For example, the Incarnation of the second Person is attributed to the Father (Heb. 10:5), to the Son (Phil. 2:7) and to the Holy Spirit (Luke 1:35; Matt. 1:20). The same can be said for a number of other divine activities in the world such as creation, redemption, sanctification and the forgiveness of sins. One reason for these statements is to bring out that all three Persons are equally active in the creation and salvation of the world.

The basic reason for saying all external activities of God are common to the three Persons is that God acts through his substance or essence and the three Persons possess that essence equally. The only distinction in God, as I pointed out before, is in the internal life of the Trinity where there is an opposition of relationship that arises from the eternal origin of the Son and the Holy Spirit. But all three Persons are equally identified with the divine Substance and, therefore, equally God. Accordingly when God acts externally all three Persons are acting.

Holy Scripture, however, very often attributes certain activities to the different Persons. Thus, works of power are attributed to the Father, the work of redemption to the Son and the work of sanctification to the Holy Spirit. These statements of the Bible do not mean that the Person in question acts alone and independently of the other two. Accordingly, even though certain "gifts" are attributed to the Holy Spirit, the actual production of those gifts in the faithful is common to all three Persons.

Why do the Bible and the Church speak in this way? Is it not confusing? It is not confusing if you reflect for a moment on what is meant. The purpose of these statements is to make manifest the differences between the Persons, that is, common attributes such as power, wisdom and goodness, and certain activities such as sanctification and creation, are attributed to a definite Person because they have a special relationship to the personal origin and property of that Person. Theologians call this use "appropriation." Appropriation is defined as a way of speaking about the Trinity in which acts common to all three Persons are attributed to an individual Person, such as sanctification to the Holy Spirit. The purpose for this is to bring out the differences between the Persons.

When we consider the divine perfections in their personal representative, they are more concrete than when we regard them in themselves or in reference to the divine substance. Thus, if I say, "God the Father, the source of the divine being, created and gives existence to the world and everything in it," that is clearer and more sublime than if I merely say, "God created the world." Likewise, do we not get a more vivid idea of the truth when we are told: "The Spirit of God moved over the waters, the Spirit of God animates everything that lives, the Holy Spirit sanctifies and purifies the creature," than when it is affirmed: "God moved over the water, God gave us life, sanctification and grace"?

It is to be noted that just as the divine nature is transmitted from the Father through the Son to the Holy Spirit, so also the external activity of the divinity is transmitted from the Father through the Son to the Holy Spirit. This does not imply that the three Persons act externally in different ways. Rather, it means that all three Persons have the same activity, but that they come into possession of it in different ways. Therefore, the external activities of the Trinity do not manifest to us the inner distinctions of the three Persons. We can know about that only through positive divine revelation.

Reading Assignment

St. Thomas Aquinas, Summa Theologica I, Q. 32, a. 1; Q. 39, aa. 7-8; Q. 42, a. 5.

Writing Assignment

Write a two-page essay explaining why all the activities of the three Persons, outside of their own internal life, are common to all three; or explain what is meant by the term "circumincession" in the Holy Trinity.

Now that we have come to some basic understanding of the teaching of Scripture and the Church about the Holy Trinity, it might be worthwhile to ask ourselves: So what? What does the doctrine of the Trinity have to do with me and the practical problems I must face every day? It has very much to do with you since, if you are in the state of sanctifying grace, the Holy Trinity dwells in you in a very special and personal way.

God is an intense and eternal lover. It was because of his love that he created you, and it is because of his love that he wishes to be united with you, to be present in you in a very special way. It is most important for us to realize that God's grace is more than merely some created thing that God imprints on us as a sign of his ownership -- it is not just a brand mark or a tag of ownership signed "God." The full meaning of sanctifying grace is that God himself, that is, the Holy Trinity -- Father, Son and Holy Spirit, is personally present in me in a way that he is not present in the rest of the material universe.

The Bible says that God, through grace, dwells in me, makes his home in me. For example, Jesus says in John 14:23, "If anyone loves me he will keep my word, and my Father will love him, and we shall come to him and make our home with him."

When the three divine Persons come to the sanctified believer, they come to him according to the special characteristics of their origin and procession. These are the truths about the Trinity that I have already explained. The NT uses the word "sending" or mission in this regard. A divine mission in this context is the procession of one Person from another with reference to a new way of existing in an external term. The point is that, because of the divine processions, the Father sends the Son, and the Father and the Son send the Holy Spirit. Thus, St. Paul says in Galatians 4:4, "God sent his Son." Both the Father and the Son are described as sending the Holy Spirit: "But the Advocate, the Holy Spirit, whom the Father will send in my name, will teach you everything and remind you of all I have said to you" (John 14:26). In the following chapter of John, Jesus says that he will send the Spirit: "When the Advocate comes, whom I shall send to you from the Father...he will be my witness" (15:26).

The Blessed Trinity is the source or cause of all creation. The final end or purpose of the universe is also the Trinity. By reason of his creative power, God is present in all creation, sustaining all things in existence. Irrational creatures, that is, all things beneath man, glorify God necessarily by their very existence. The glory of God from rational creatures requires free worship, praise and honor. Through the sin of our first parents, Adam and Eve, we lost the grace that God had intended for us to have. That situation was abundantly restored by the Incarnation of the second Person of the Blessed Trinity in Jesus Christ. God's will is that through faith in Jesus Christ, the acceptance of Baptism and incorporation into his Church, we should be made temples of the Holy Spirit, children of God and heirs of heaven. This is all accomplished through the indwelling of the Holy Trinity in the souls of the just.

The "indwelling" means that Father, Son and Holy Spirit become personally present to us through grace in a unique way. Their presence in the soul affects both our knowledge and our love. When the Bible speaks about "sending" or "mission" of the Son and the Holy Spirit it is referring to the special way in which they proceed in the Trinity itself. The temporal missions, therefore, reflect the individual characteristics of the divine Persons: The Father sends, but is not sent; the Son is sent and sends; the Holy Spirit is sent, but does not send.

In the course of salvation history, or God's dealing with mankind, we discover both external and internal divine missions. They could also be called visible and invisible missions. Thus, the Word of God became man in Jesus of Nazareth. That is what is meant by a visible mission. The Holy Spirit appeared under the form of a dove at the Baptism of Jesus (Matt. 3:16), under the form of a brilliant cloud at the Transfiguration of Jesus on Mount Tabor (Matt. 17:5), and under the form of tongues of fire in the upper room on Pentecost (Acts 2:3-4).

The visible missions are external signs of the invisible missions, namely, the Trinity dwelling in the souls of the just. This means that the Son and the Holy Spirit are present in a new manner in creatures. It is a new, interior and invisible presence, which sanctifies the soul and imparts to it a new supernatural life. The Father is also present in the sanctified soul because, as we have seen, where the Son and the Spirit are present, the Father, who is one with them, is present also. So when we pray to God within us we should pray to the Father, through the Son, in the Holy Spirit.

The sending of the Son and the Holy Spirit is expressed in the following texts: John 5:23; 6:38-39; 7:28;14:26; 15:26; 16:7; Galatians 4:4 and 6.

The indwelling in the soul of the just is common to the three Persons. We know, because consubstantiality and circumincession, that one Person cannot dwell in the soul without the others. Therefore, the indwelling is necessarily common and so the formal reason for the indwelling cannot be something personal, but it must be something substantial, namely, participation in the divine nature.

What is proper to the individual Persons in God is only what is of a relative nature or hypostatic nature. But indwelling or union with the soul of the just, however it is understood, cannot pertain to the relative order ad intra nor to the order of a hypostatic union. Therefore there cannot be found in the Holy Spirit any special reason because of which he is communicated to the just, and which would be the reason why the other Persons are communicated. In this there is a difference with the Incarnation which pertains to the Hypostasis as such. Therefore, the three persons cannot inhabit or be united to the soul of the just because of an individual or singular title, but only a common title.

This consideration brings us back to the notion of appropriation, which means attributing to one Person something that is common to all three. Appropriation is its positive foundation in the frequent and emphatic attribution in the Bible to one Person what is also said of the others. The indwelling in the just, both in Scripture and in the Fathers, is affirmed of the three Persons but frequently it is attributed to the Holy Spirit.

At the end of this course you should now be able to penetrate more deeply into the meaning of two key texts about the Trinity:

2 Cor. 13:13, The grace of the Lord Jesus Christ and the love of God and the fellowship of the Holy Spirit be with you all.

Matt. 28:19, Go therefore and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit.

Reading Assignment

St. Thomas Aquinas, Summa Theologica I, Q. 42, a. 5; Q. 43, aa. 1-8.

Writing Assignment

Write an essay of two to three pages on the divine missions and the indwelling of the three Persons of the Trinity in the soul of the just.

Here are a few books that a student of the Holy Trinity may find helpful; some of them contain suggested readings for those who take the course for credit.

Aquinas, St. Thomas, Summa Theologica, Part I, Questions 27-43.

Augustine, St., De Trinitate (On the Trinity).

Catechism of the Catholic Church (The Catholic Book Publishing Co., New York, 1994).

Farmer, William A., The International Bible Commentary (The Liturgical Press, Collegeville, Minn. 1998).

Jesuit Fathers of St. Mary's College, The Church Teaches. Documents of the Church in English Translation. (Tan Books, P. O. Box 424, Rockford, IL 61105). (Contains most of the important references to Denzinger -- in English).

Jurgens, William A., The Faith of the Early Fathers. Three Volumes. (The Liturgical Press, Collegeville, Minn., 1979). (Contains most of the references to the Fathers of the Church -- in English. This is the English translation of Rouet de Journel, Enchiridion Patristicum.)

New Catholic Encyclopedia. Fifteen Volumes (1967). Select articles on aspects of the Trinity.

Ott, Ludwig, Fundamentals of Catholic Dogma, pp. 50-75. (Tan Books).