Catholic theology tells us that there are three absolute mysteries of our faith: the Trinity, the Incarnation, and divine grace. They are called absolute mysteries because no created intellect can comprehend them, not even the angels or souls in beatitude. We know of these mysteries only because God has chosen, in His goodness, to reveal Himself through scripture, through the words of His prophets, and finally, through the Incarnation of the Word in Jesus Christ. Through the words of Christ as reported by the evangelists and the teachings of the Apostle Paul, we see allusions to the mystery of the Trinity. In the two infancy accounts from Matthew and Luke, each gospel points toward the personal in God in the unusual circumstances of Jesus’ conception and birth. However, our first glimpse into the relational life of the Trinity is given to us in the unanimous witness in all four gospels of the account of Jesus’ baptism. In the three synoptic gospels, the evangelists relate that the heavens open, Jesus sees the Holy Spirit descending on Him in the form of a dove, and He hears the Father speaking the words of affirmation. In the Gospel of John, the evangelist relates what is more of an eyewitness account by John the Baptist:
“I saw the Spirit descend as a dove from heaven, and it remained on him, I myself did not know him, but he who sent me to baptize with water said to me, ‘He on whom you see the Spirit descend, this is he who baptizes with the Holy Spirit.’ And I have seen and born witness that this is the Son of God.” (1:32–34, RSV).The final verses of the Gospel according to Matthew also attest to three persons: “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” (28:19). St. Paul, too, attests to the persons of the Father and the Son (Romans 8:32) and also to the Holy Spirit given to us as gift (Romans 5:5). Scripture, then, gives one sufficient witness of the Persons in God, yet still there is little to explain how One is Three.
Much of the early doctrine on the Trinity comes by way of the works of the Cappadocian Fathers, St. Cyril of Alexandria, and St. Augustine. The early councils of the Church and their resulting creeds teach two processions within God (Denzinger 86). The work of the early Church Father mentioned above help the faithful to understand that these processions correspond to the two internal activities of God, thinking and willing. In respect to these processions, St. Augustine wrote, “For the mind cannot love itself, except also it know itself; for how can it love what it does not know?” (9, 3, 3) This first procession, that of knowing, is called generation, and the second, that of willing or loving, spiration. The result of each procession is a Person, yet a Person sharing the same Divine nature as the origin and subsisting in that nature. What does this mean for a Person to subsist in the Divine nature?
As St. Thomas notes in Summa Theologica, a person as defined by Boethius is “an individual substance of a rational nature” (I. 29. 1). One typically thinks of an individual substance as a discrete being, and in creatures this identification would be correct. However, in God, being or nature is not discrete but communal and possessed by three Hypostases. Thus,
[B]ecause subsistence in a rational nature is of high dignity, therefore every individual of the rational nature is called a “person.” Now the dignity of the divine nature excels every other dignity; and thus the name “person” pre-eminently belongs to God. (I.29.3)These persons in the Divine Being are not distinct by nature, but only by way of the relation each has to the origin. Ott explains that relation indicates an ordination or ordering of one thing to another and describes three elements in a relation: principle (origin), aim (term), and the basis of the relation (fundamentum). The Father is the origin. The Son is generated from the Father. The Holy Spirit proceeds from Father and Son. These Persons, then, are said to signify relations in God, or as St. Thomas averred, “Therefore a divine person signifies a relation as subsisting” (I.29.4).
We count three Persons in the Trinity, yet the Church teaches four real relations in the Trinity. To understand this teaching, one must go back to the notion of the processions. Two processions result from the two activities in God. The first is called generation. Fr. Kenneth Baker describes generation as “the origin of a living being from another living being, both having the same nature.” In the Divine generation, the intellect of God knows Itself, and this knowledge of self produces a perfect image, the Word. In this generation, there is a principle, the Father, and a term, the Son. As two Persons result, they exist in relation to one another. As the Father generates the Son, His relation to Son is called paternity. This relation is the action of the principle toward the Son. St. Thomas notes, citing Augustine, that real relation in God can only be based on action because there is no quantity in God (I.28.4). From this action moving from origin to term, two relations result. The first, paternity, identifies the origin as Father. The second relation is referred to as filiation because the term of generation (the Son) is a Person of the same nature as the Father. As the Angelic Doctor explains, “two opposite relations arise; one of which is the relation of the person proceeding from the principle; the other is the relation of the principle Himself” (I.28.4).
The next procession results from an act of will, specifically an act of mutual love between Father and Son. The Father is the origin, but the action takes part on behalf of both Father and Son. The term of the action is the Holy Spirit. While the scriptural basis for this teaching is clear, it was nonetheless a source of controversy in the ninth century, when a patriarch, Photius, rejected the teaching as heretical. Yet scripture states that all that the Father has, He has given the Son (John 16:16) and that the Son (John 15:26, 16:7) sends the Holy Spirit who has proceeded from the Father. If the Father has given the Son everything, then He has given the procession of the Holy Spirit as well. Hence, this action moves from the Father and Son as a single principle, and results in the Holy Spirit as term. Again, as with the first procession, two real relations result. First, is the action of the Father and Son as a single principle, which has come to be known as spiration, as it results in a term, the Holy Spirit. In this process, the action is referred to as the relation of active spiration, while the term or recipient of action is called the relation of passive spiration. All together, we have four real relations in God: Father to Son, Son to Father, Father and Son to Holy Spirit, and Holy Spirit to Father and Son.
At this point, one can acknowledge four relations, but within a single being, how are these relations real rather than just logical relations—that is, actual relations or just a means by which we think about and compare two things? St. Thomas points out that when something proceeds from a principle of the same nature, the relation is not simply logical but real (I.28.1). Thus in the Trinity are four real relations. Yet, if there are four real relations, why is God triune rather than quadruple? The answer to this question lies in the nature of the relations. Relations imply distinction, and in the Godhead, there exist principles and terms in opposition to each other. In the first procession (generation), Father is opposed to Son in that one (the principle) is active, and the other (Son), passive. In the second procession (spiration), the Father and Son are active as one principle, and the passive spiration of the Holy Spirit is opposed to them. Active spiration is opposed to passive spiration but not to the Father and the Son. Thus it is not distinct from them. So while the real relation of active spiration exists, it does not result in a person distinct from the other Persons of the Trinity.
By reason, we can know God, but only through revelation can we know of His internal life. Through the Incarnation, we come to know three Divine Persons, the Unbegotten, the Begotten, and the Love between them: three Persons from four real relations in One Divine Being.
1. “Aristotle,” Internet Encyclopedia of Philosophy. October 21, 2005. http://www.iep.utm.edu/
aristotl/ (accessed November 7, 2011); also Carl Huffman, “Pythgoreanism,” The Stanford Encyclopedia of Philosophy, http://plato.stanford.edu/archives/sum2010/entries/pythagoreanism/ (accessed November 7, 2011).
2. Kenneth Baker, Fundamentals of Catholicism, (San Francisco: Ignatius, 1983) 79.
3. Ludwig Ott, Fundamentals of Catholic Dogma, (Rockford, Illinois: Tan Books and Publishers, Inc., 1974) 68.
4. Ott, 67–68.
5. Baker, 93.
6. Ott, 66.
7. Ibid., 62–63.
9. Baker, 98
10. Ibid., 101.
11. Ibid., 102.
Aquinas, Thomas. “Summa Theologica, Prima Pars.” New Advent. 2000. http://www.newadvent.org/summa/1027.htm (accessed October 6, 2011).
“Aristotle.” Internet Encyclopedia of Philosophy. October 21, 2005. http://www.iep.utm.edu/aristotl/ (accessed November 7, 2011).
Augustine. “On the Trinity.” New Advent. Edited by Phillip Schaff. 1887. http://www.newadvent.org/fathers/130104.htm (accessed October 7, 2011).
Baker, Kenneth. Fundamentals of Catholicism. San Francisco: Ignatius, 1983.
Catechism of the Catholic Church. Washington D.C.: United States Catholic Conference, 1997.
Denzinger, Henry. The Sources of Catholic Dogma. Fitzwilliam, New Hampshire: Loreto Publications, 1954.
Huffman, Carl. “Pythgoreanism.” The Stanford Encyclopedia of Philosophy. Edited by Edward N. Zalta. Summer 2010. http://plato.stanford.edu/archives/sum2010/
entries/pythagoreanism/ (accessed November 7, 2011).
Ott, Ludwig. Fundamentals of Catholic Dogma. Rockford, Illinois: Tan Books and Publishers, Inc., 1974.