6. ST. AUGUSTINE AND ST. THOMAS ON THE TRINITY

In his commentaries on the Gospel of St. Matthew and that of St. John and on the epistles of St. Paul, St. Thomas examined all the texts of the New Testament in which the Holy Trinity is mentioned explicitly or implicitly. In his consideration of this subject, he clearly understood how much St. Augustine was able to contribute toward the understanding of these texts. His debt to St. Augustine will become evident from a comparison of the works of St. Augustine with the writings of the Greek Fathers.

1. The method of the Greek Fathers. In their refutation of Sabellius, who had denied the real distinction between the divine persons, and of Arius and Macedonius, who had denied the divinity either of the Son or of the Holy Ghost, the Greek Fathers began with the affirmation of the three persons, as found in Sacred Scripture, and then they tried to show that this Trinity of persons could be reconciled with the unity of nature by reason of the consubstantiality of the persons. This idea of consubstantiality was more and more explicitly stated and then defined in the Council of Nicaea.[121]

Thus the Greek Fathers, especially St. Athanasius, showed that, according to revelation, the Father begets the Son by communicating to Him not only the participation of His nature but His whole nature, and from this it followed that the Son was consubstantial with the Father and true God from true God. This also explained how the incarnate Son of God was able to redeem us from the servitude of sin, because His merits had infinite value.[122] In the same way the Greek Fathers showed that according to Sacred Scripture the Holy Ghost, proceeding from the Father and the Son, was God and therefore was able to sanctify our souls. Indeed these processions were looked upon as donations and communications rather than as operations of the divine intellect and will: the Father, in begetting the Son, gave Him His nature. Similarly, the Father and the Son gave or communicated the divine nature to the Holy Ghost, who proceeded from them. But in this concept, the manner in which the first and second processions took place remained inscrutable.[123] In their explanations of this mystery, the Greek Fathers followed the order of the Apostles' Creed, in which the Father is called the Creator, the Son the Savior, and the Holy Ghost the Sanctifier. The explanations proposed by the Greek Fathers contained, it must be said, many obscurities.

2. The difficulties of the Greek Fathers. Why are there two processions and only two? How does the first differ from the second, and why is the first procession called generation? In other words, why is the Son of God only-begotten, and why does the Holy Ghost, although not begotten, receive the whole divine nature?

One other doubt arises: Why, in the Apostles' Creed, is the Father alone called the Creator, whereas in the prologue of St. John's Gospel and in the epistles of St. Paul all things are said to have been made by the Word? The creative omnipotence is an attribute of the divine nature and therefore it is something common to the divine nature and pertains to the three divine persons. The Greek Fathers did not explain in what sense the Father alone is called the Creator in the Creed.

To solve this difficulty, St. Augustine and his successors adopted the theory of appropriation, which is found only implicitly in the Greek Fathers. The Latins explained that the Father is called the Creator, not because He alone created, but by appropriation, that is, by a similitude of propriety, for "the creative power contains the idea of principle and therefore has a resemblance with the heavenly Father, who is the principle in the divinity."[124] In the same way wisdom has a resemblance with the Son inasmuch as He is the Word.

3. St. Augustine's solution of these difficulties. To arrive at a solution of these problems, St. Augustine labored long in the writing of his great work, De Trinitate, in fifteen books; the first seven books explain the biblical texts referring to the Trinity, and the other eight treat of the mystery speculatively, proposing analogies taken from the human soul, inasmuch as the word of the mind proceeds from it by intellection as well as love, which is the inclination or weight of the soul drawing it to the good as loved. St. Augustine laid great emphasis on the fact that according to the Fourth Gospel the Son proceeds from the Father as the Word; "And the Word was with God and the Word was God. The same was in the beginning with God. All things were made by Him... ."

The Son, who is called only-begotten (v. 18), proceeds therefore from the Father as the Word, not as the Word produced and delivered exteriorly, but as the Word of the divine mind, for it is said, "The Word was with God, and the Word was God." The Word, then, is God, not the supreme creature, and "all things were made by Him." In the Epistle to the Hebrews, we read, "Who being the brightness of His glory, and the figure of His substance[of God the Father], and upholding all things by the word of His power."

St. Augustine explains the intimate manner of the generation of the eternal and only-begotten Son, while the Greek Fathers said that the manner of His begetting was inscrutable. Explaining the prologue of St. John's Gospel, St. Augustine showed that the Father from eternity begets His Son by an intellectual act just as our mind conceives the mental word: in the soul we find the mind, knowledge, and love; in the soul, which is the image of the Trinity, there are memory, intelligence (the act of intellection), and the will. This helps us to understand the fecundity of the divine nature.[125]

But while our word is only an accident of our minds, remaining very imperfect and limited, and multiple to express the diverse nature of things, the divine Word is something substantial, most perfect, unique, perfectly expressing the divine nature and all that it contains. It is therefore truly "light of light, God of God, true God of true God." Thus, by the analogy of our intellectual word, by its similarity and dissimilarity, the intimate manner of the first procession is explained. The manner of the second procession, which appears as the procession of love, is also explained. From our souls, which according to the Scriptures are created in the likeness of God, proceeds not only the word but also love. The human mind not only conceives the true-good but also loves it. If therefore the only-begotten Son proceeds from the Father as the mental Word, the Holy Ghost is to be considered as proceeding from them as love.

Thus it is that there are in God two processions and only two, and the manner of each is explained. St. Augustine, however, did not understand why the first procession is called generation. St. Thomas explains: "The Word proceeds by intellectual action, which is a vital operation, conjoined to the principle, and after the manner of a likeness, because the intellectual concept is an image of the thing understood."[126] The concept of our minds, however, does not deserve the name of generation, because in us the concept is only an accident of our minds, whereas in God the Word is substantial inasmuch as intellection in God is subsisting being. Thus the Father, in producing the Word, begets a Son like to Himself, and does not produce an accidental mental word.

St. Thomas further perfected the doctrine of St. Augustine by showing why the procession of love should not be called generation: "the will is in act, not because some likeness of the thing willed is in the will, but because the will has a certain inclination toward the thing willed."[127] In St. Augustine's words, "My love is my weight."

In the doctrine proposed by St. Augustine we also find an explanation of why the Holy Ghost proceeds not from the Father alone, but also from the Son, because in our souls love proceeds not only from the soul itself but from the knowledge of the true-good, since nothing is loved unless it is also known.

From this it appears that in his thinking about the Trinity, St. Augustine did not begin with the three persons as did the Greek Fathers but rather with the unity of the divine nature, which was already demonstrated by reason, just as he began with the soul itself in his demonstration of its faculties and superior operations.

In these two approaches opposing difficulties arise: in the Greek approach it is difficult to safeguard the unity of nature, while in the Augustinian approach, starting with the unity of nature, it is difficult to safeguard the distinction between the persons and those things which are proper or appropriated to the persons. It is, after all, a transcendent and indemonstrable mystery. But by these two approaches, the first of which is the more concrete and the second is more abstract, the mystery is contemplated under two aspects. And finally, the abstract principles serve to advance a better understanding of what is known beforehand in a concrete manner.

St. Augustine and his followers easily explained what the Greek Fathers were not able to show: why the Father alone is not the Creator, but also the Son and the Holy Ghost, because the creative power is a property of the divine nature, common to the three persons. Gradually was unfolded the meaning of the traditional principle: the three persons are one principle in the operations "ad extra". This principle was formulated in the condemnations by Pope Damasus in 380, and later councils defined it more accurately.[128] Great progress was thus made in the elucidation of this dogma.

When, in the Apostles' Creed, only the Father is called the Creator, the predication is not proper and exclusive; it is rather by a kind of appropriation, inasmuch as the creative power contains the notion of principle "ad extra" just as the Father is the principle "ad intra." In the same way, wisdom has a resemblance with the Word, and our sanctification has a resemblance to the Holy Ghost, since it proceeds from God's love for us, and thus the Holy Ghost is called the Spirit of love or personal love.

Therefore, while consubstantiality was the terminus toward which the Greek Fathers tended, beginning with the three persons, whose names are found in Scripture, St. Augustine, on the other hand, began with the unity of the divine nature to arrive at the three persons, just as he began with the unity of the soul to determine its superior operations and the various manifestations of its life.

In the Augustinian doctrine, gradually that principle which illumines the whole treatise on the Trinity and was formulated by the Council of Florence in 1441, came to light, "In God all things are one and the same unless there is opposition of relation, " that is, where there is no relative opposition between the persons, all things are one and the same because the divine nature is numerically one with all its attributes.[129]

4. The difficulties of the Augustinian teaching solved by St. Thomas. Two difficulties remained in the Augustinian doctrine. The first arose from the fact that the generation of the Word takes place after the manner of intellection; but the three divine persons have intellect; therefore the three divine persons ought to beget, and then there would be a fourth person, and so on to infinity. This difficulty is solved by the distinction between intellection and the expression of the notional idea inasmuch as the three persons all have intelligence but only the Father expresses the intellection. He alone expresses because the Word is adequate and the most perfect expression of the divine nature and no other Word need be enunciated. Just as in a classroom while the teacher is teaching, both he and the pupils understand, but the teacher alone enunciates. Similarly a difficult question may be proposed to a number of persons; then one discovers and expresses the correct solution, while all the others immediately understand it. This distinction between intellection and enunciation is offered by St. Thomas.[130]

The second difficulty is similar: the second procession takes place after the manner of love; but the three persons love; therefore the three persons ought to spirate another person, and so on to infinity.

The solution of this difficulty depends on the distinction between essential love, which is common to the three persons, and notional love, which is active spiration and corresponds to the enunciation of the Word. It is called notional because it denotes the third person. Thus the three persons all love, but only the first two spirate. We have then three kinds of love in God: essential, notional, and personal. Personal love is the Holy Ghost Himself, who is the terminus of active spiration just as the Word is the terminus of generation and enunciation.[131] According to a rather remote analogy: a saintly preacher loves God and inspires his audience with this love, and the hearers also love God but they do not inspire others with this love. These two distinctions are not explicitly found in St. Augustine, but after his time great progress was made in elucidating the traditional doctrine of the Trinity.