This paper is original writing by Audrey Carroll and was written in partial fulfillment of the requirements of EH 340 at The University of Alabama in Huntsville under Dr. G. Hubbell, Spring 2020.
The doctrine of the Trinity has long been a topic of great discussion and debate among those within and without the realm of Christianity. This debate has extended into the discussions among Christians about the necessity of holding to a concrete understanding of the Trinity. They question whether or not the Trinity is Biblical, and, if it is Biblical, how can it be tangibly defined? In this paper, I argue that forming and holding to a Biblically based doctrinal understanding of the Trinity is necessary and practical for the Christian. Without such an understanding, all other doctrines within the Christian faith will crumble because of an unstable foundation of the Triune, three-in-one (OED), God at the center of everything. I will analyze what Thomas Aquinas says about the Trinity in Treatise on the Trinity, what God says about Himself in the Bible, and what others say about these two sources collectively.
When considering oppositional sources, Herbert McCabe, in his article “Aquinas on the Trinity,” attacks Aquinas’ presentations of the Trinity because he cannot reconcile an incomprehensible view of God to the physical reflections of God that are seen in creation. However, McCabe does not take into account the Biblical foundation for Aquinas’ arguments, that his arguments are sourced solely from the Bible. Contrarily, Aquinas’ presentation is Biblically solidified because its concepts are derived entirely from Scripture, and, when understanding this view, it may become incredibly easy to reconcile the incomprehensible with the visible. This paper will use the Bible as the basis for analyzing the doctrine of the Trinity as it is according to Aquinas, McCabe, and other commentators. Ultimately, my goal is to show how the doctrine of the Trinity is a good and necessary doctrine that glorifies God and enables man to experience and enjoy Him in a way that uniquely reflects the Trinity.
In approaching any doctrinal argument with a Biblical basis, one must thoroughly consider what the Bible says. For Christians, it is the absolute foundation for any pursuits and studies. However, it is not simply enough to weigh into consideration the bare words of the Bible. It must be approached objectively and entirely as a book, without removing passages from context in which they exist in the grand metanarrative of Scripture. Similarly, analyzing the doctrine of the Trinity must be based solely on the words contained in the Bible, thus the conclusions within the words of Aquinas and his theological peers must be held to the standard of the Bible. The Bible is self-credible, stating clearly in the book of 2 Timothy, “All Scripture is inspired by God and profitable for teaching, for reproof, for correction, for training in righteousness” (3:16). The original Greek word for “inspired” in this verse is crucial to the foundation of any Biblical arguments: Theopneustos, literally meaning “divinely breathed in” (“Theopneustos”) offers a self-credibility for Scripture Therefore, all commentaries regarding Biblical subject matters may rightly be held to this standard. It is sufficient for the formation and defense of any doctrines which come directly from its pages.
The relations of a Triune God, of which there are four definitions, are crucial to understand. “Innascibility” is the eternal non-generation which belongs solely to God the Father (Duby para. 6). “Filiation” is the eternal sonlike procession from the Father which characterizes only God the Son (para. 6). “Common spiration,” or the eternal bringing forth of the Holy Spirit, belongs jointly to God the Father and God the Son (para. 6). Finally, “procession” is the “coming forth from the Father and Son” (para. 6). These definitions have been widely accepted and applied since the publishing of the Niceno-Constantinopolitan Creed, or the Nicene Creed, in 325 AD (Mathison 6), and they are crucial for any successful discourse about Trinatarian doctrine. This Creed gave local churches a more well-rounded understanding of the global church’s understanding and application of the Trinity as found in the Bible.
What Aquinas Says about God
Aquinas’ massive doctrinal dissertation Summa Theologiae and its excerpt Treatise on the Trinity analyze various qualities about both God Himself and Christianity as a whole, and Aquinas positions himself in a way that is prepared to answer objections. The work is set up so that he is able to present qualities about the Trinity, their subsequent objections, and answers to those specific objections. Aquinas defends the doctrine of the Trinity from the position that it is a defense of God’s character rather than God’s substance. Though the word “Trinity” is used nowhere in the Bible—and Aquinas readily acknowledges this fact—Aquinas responds, “The name ‘Trinity’ in God signifies the determinate number of persons. And so the plurality of persons in God requires that we should use the word trinity; because what is indeterminately signified by plurality, is signified by trinity in a determinate manner” (107). The reader can draw from this the conclusive reality that the doctrine of the Trinity results from plurality present within the Bible. Aquinas also defends the doctrine of plurality, the understanding that there are three distinct persons within a singular God by bringing up the doctrine of the hypostatic union (95). Hypostasis, or a hypostatic union, is defined by “each person [being] identical to the other in terms of the divine essence, but each has a distinct personal property that they do not share in common and that do not pertain to the divine essence or being” (Mathison 7). Aquinas notes that “hypostatic union,” though often used to refer to three separate substances, is unified in God by three separate essences being one within the Godhead. He cannot be three separate gods, for to be three separate gods would be entirely contradictory to the first commandment: to have no other gods before Him (Exodus 20:3). How then can the proposed idea of three-in-oneness not contradict the commandment? God is not contradicting Himself by revealing His nature. Rather, He is proving His omnipotence, omnipresence, and omniscience. In possessing three distinct persons, He is supreme commander of all other power, all of time, and all events of history past and future.
Further, Aquinas states that although there are four relations in God—paternity, filiation, common spiration, and procession—that does not mean that God is four-parted (98). His defense to this opposition of a multiplicity of gods is the simple characterization of each of the three persons of the Trinity. Paternity, or fatherliness, belongs to God the Father; filiation, or eternal sonship, belongs to God the Son; and procession, or co-eternality, belongs to God the Spirit (98). These unique characteristics are what contribute to common spiration, or the idea that the Spirit proceeds directly from the unity of the Father and the Son (128). However, despite the seeming disorder or disunion that might be created by individual relations, Aquinas says “in the divine Trinity not only is there unity of order, but also with this there is unity of essence” (107), and “in God there is not triplicity, but Trinity” (108), the latter referring to a unity, and the former referring to a disunity. These four relations are what propel the story of the Bible: that God created all things, man fell into sin, God sent His Son, the Son died and rose again, and the Spirit was sent to indwell believers where He will reside until the Son returns. Finally, in an effort to avoid a heretical downfall, Aquinas presents the word “distinction” which prevents one from coming to the easy, though false, conclusion that there is a separation between the persons of the Trinity (109-110). A separation would result in utter chaos, preventing God from operating in an orderly manner as is represented throughout both the Old Testament and the New Testament. For Aquinas, what may be perceived from the outside as chaos is not chaos but is perfect order and alignment with what is communicated in the Scriptures. When comparing how Aquinas characterizes God in Treatise on the Trinity, it becomes evident how Aquinas could not have come to his conclusions based solely on his own reason but on the Bible alone. Therefore, any argument about the character of God that is not based solely on the Bible is futile at best.
What God Says about Himself
It is crucial to note that a triune God is not a multiplicity of gods. As previously noted, if God were a multiplicity, He would be contradicting His own commandment to worship only Him. The unity of the Trinity is what makes God so gloriously incomprehensible: that He, existing in three distinct and eternal persons, would exist in one unity so that He is singularly worshiped by His people and the whole of creation. Certainly, the God of the Bible is unified and singular, though He exists in three distinct persons. In this three-in-oneness, God equips and sends out His people to evangelize, commanding them to “Go therefore and make disciples of all the nations, baptizing them in the name of the Father and the Son and the Holy Spirit” (Matthew 28:19). This commandment is rooted in the presentation of a single name which encompasses three persons. In the case of discussing Biblical doctrine, grammar is the final say. Therefore, the usage of the singular “name” from this passage should result in a closed case. However, this establishment is not present solely in the New Testament. This crucial Trinity-based command is the fulfillment of the Old Testament command given to the Israelites in Exodus 20:3, that God would be solely worshiped by everyone everywhere. The Trinity is for the glory and fame of God. In this grand communion, the people of God may experience the person of God in three unique ways that individually relate to the three persons of the Trinity. The Father is experienced in beholding the wonders of creation. The Son is experienced through the outpouring of love on the cross and victory over death. The Spirit is experienced in the growth of the heart of the believer, drawing the Christian into a life that is an ever-improving reflection of God. Tyler Smith reflects on the Trinity by stating:
When we glimpse the beauty of this teaching [of the Trinity]—not in spite of, but because of its rich complexity—its implications stretch before us in ever-widening circles: from the very reason for our existence, to the way we live our lives, to the way we treat one another, and even to the way we relate to other religions and worldviews… Perhaps most precious of all, the doctrine of the Trinity reveals that woven into the very fabric of the universe is the self-giving love of God. (paras. 28-29)
This life-guiding worldview of the Trinity points humanity back to the loving Creator who so desires His children to know Him that He chooses to reveal Himself in a Triune way. Such an existence, though far more complex to understand, displays His goodness by relating to creation in different and unique ways.
Simultaneously, as the Trinity is for the glory of God, the Trinity is also for the good of Christians. 2 Corinthians 1:21-22 states: “Now He who establishes us with you in Christ and anointed us is God, who also sealed us and gave us the Spirit in our hearts as a pledge [of His faithfulness (see also verse 18)]” (NASB). Christians have a solidified foundation in Christ, are anointed in that faith by God, and are sealed in the walking of that faith by the gift of the indwelling of the Spirit. The three-in-one unity propels the Christian forward in unity within the church, allowing the Christian to live a life that is focused on the eternal, knowing that the divine and incomprehensible character of God is a sufficient seal for such a promise that this life is not the end. This unity that is experienced and enjoyed by the church, though not untouched by human failures, is a perfect reflection of the unity that is present in the Trinity. Christians within the church are able to move forward to one goal, the glory of God, through the studying and teaching of the Scriptures. In the study of the Scriptures, the Christians is educated to know God more and equipped to experience Him more fully. In teaching the Scriptures, the Christian is edified in the continuing education and exhorted in the continuation of the command that Jesus gave in Matthew 28. Furthermore, in this Tri-unity, the believer is forged into reflections of Jesus the Son Himself, and this process of being made holy uniquely allows the Christian to further enjoy God and glorify Him more. After all, “man’s chief end is to glorify God… and enjoy him for ever” (“Westminster” Q1.A1). If God was reduced to the simple level of what He created, He would not be worthy of worshiping because He would be merey equated to a product of creation as well. If this leveling were the case, experiencing Him would not be as wondrous as what is presented in the Bible. Rather, since God is a Trinity, He may be experienced beyond a physical level as that of creation, benefiting the life of the Christian in countless ways. Further, the Trinity is indicative of God’s ability to faithfully fulfill His promises to His people. This faithfulness can be seen in Luke 1:35 when the angel Gabriel came to Mary, telling her about the coming of the baby Jesus: “The angel answered and said to her, ‘The Holy Spirit will come upon you, and the power of the Most High [the Father] will overshadow you; and for that reason the holy Child [the Son] shall be called the Son of God’” (NASB). The promise of God coming in the flesh is the equipment that the church needs to be able to carry out all of the unity in and enjoyment of God Himself.
Since the time of Aquinas, there has been much dispute within the church regarding the necessity of the doctrine of the Trinity. While some have misinterpreted its divine characteristics, many have denied its importance altogether. However, the Apostle Paul, in writing the book of Ephesians would strongly disagree, saying, “There is one body and one Spirit, just as also you were called in one hope of your calling; one Lord [Jesus], one faith, one baptism, one God and Father who is over all and through all and in all” (4:4-6). Without the Trinity, Christianity would not exist because it would have no foundation in spreading. A loving God who displays His love through His three persons—Father, Son, and Holy Spirit—is active in the lives of all Christians to unify them in Him and enable them to live temporal lives that are focused on and encouraged by the eternal. The doctrine of the Trinity is the doctrine of the Gospel; one cannot remove one without destroying the other. In his article “Is the Trinity Biblical?”, Keith A. Mathison identifies the doctrine of the Trinity as a Biblical basis of concision: that there is only one God; that the Father is God; that the Son is God; that the Holy Spirit is God; and that the Father, Son, and Holy Spirit are distinguished (5-6). Interestingly, the doctrine of the Trinity caused such an uproar in the early church that they deemed it necessary to create a statement about what the Bible teaches about the Trinity. The Nicene Creed was birthed to defend the characteristics which are essential to communicating how God is represented as Triune in Scripture, thus laying to rest some arising heresies which were destroying unity within the Church (Fesko 24). In criticizing even one element of the Trinity, by simply denying that the Holy Spirit is fully and equally God, sends a domino effect throughout all of Scripture. Therefore, the doctrine of the Trinity is necessary for the function of the Christian life, fueling the relationship between mankind and God Himself. Because of the overwhelming proof of the existence of the Trinity present throughout all of Scripture, saturated in the Old Testament and the New Testament, Mathison’s answer to the question of whether the doctrine of the Trinity is biblical is fitting: “Without a doubt” (7).
What Others Say about what Aquinas Says (or Commentary)
In his article “Aquinas on the Trinity,” Herbert McCabe’s primary opposition to Aquinas’ writings on the Trinity is his reliance upon abstractness. He often notes Aquinas’ assumption that his reader is familiar with the grandiose theological vocabulary used in Treatise on the Trinity, but McCabe himself does not believe that all of Aquinas’ readers even agree with his outlined oppositions. McCabe’s frustration is Aquinas’ acknowledgement that a Trinitarian doctrine does not logically make sense (538). Further, where Aquinas argues for a wonderfully mysterious yet practically known view of God, McCabe seems to believe that God is far more tangibly known to humankind. However, this belief—that God is easily known because God is creation—is exactly what Aquinas attempts to eliminate in his writings. Where Aquinas argues that God is distinct from creation because of His existence that was without beginning (Psalm 102:24-25; 1 Timothy 1:17), McCabe asserts that God is understandable because of what is readily known about creatures, leading to the suggestion that God Himself is a created being (537-538). If this is the case, then there is no need for a Trinitarian understanding of God. In fact, there would be no need for a god who is not powerful enough to be so beyond the bounds of time that he is capable of aiding his children, and McCabe readily notes this failing of logic (541). Alas, such a weak god is not the God of the Bible. He has made Himself readily known throughout Scripture, proving to be a simultaneously loving and wrathful God, and once one attempts to think about God outside of the bounds of Scripture, such logic only proves baffling. McCabe’s concluding argument against Aquinas is the idea that a three-in-one God must mean that within God is contained three uniquely individual “knowledges” (556). However, this notion must not be based on relations but on person. The Trinity is not, as seen clearly in Scripture, based in a three-personness, and Aquinas is prepared to thoroughly answer this opposition.
As if anticipating the rejection of the notion of God, Aquinas writes:
Reason is employed… not as furnishing sufficient proof of a principle, but as confirming an already established principle, by showing the congruity of its results, as in astrology the theory of eccentrics and epicycles is considered as established, because thereby the sensible appearances of the heavenly movements can be explained… (122)
The basis for Aquinas’ rebuttal is likely based on Romans 1:20 which states that creation is sufficient evidence for the glory of God, denying the notion that creation itself contains God. McCabe’s conclusion is the questioning of the usage of the word “God.” He writes: “…[A]ll this argument is based not on any knowledge or understanding that we have a God; it is simply what we are compelled to say if we are to use the word ‘God’ correctly…” (542). It must be concluded, then, that McCabe’s questioning is not simply focused on the Trinity; rather, his questioning is largely focused on the dependability of God.
Conversely, Steven J. Duby’s “Trinity and Economy in Thomas Aquinas” is in full agreement with Aquinas’ Trinitarian works. He simplifies and summarizes the characteristics of a monotheistic Triune God, specifically addressing the “notion” of God, or the idea that God can be fully understood and comprehended by the human mind (para. 6). For Duby, as well as the historic orthodox church which held to specific doctrinal beliefs as based solely on the Bible, understanding God through these four relations does not humanize Him, but it does allow the human mind to comprehend His characteristics in a more well-rounded way. Further, he defends the widely-held monotheistic view of a Triune God, stating:
To connect [these relations] at a very general level to contemporary debates about the distinctions among the divine persons, it is worth noting that Thomas [Aquinas] does not envision any faculties (intellect, will) or inhering features that might distinguish the persons, only their relations to one another. (para. 7)
Contrary to McCabe’s position, Duby’s position is that possessing a notion of God does not level Him with creation, as such a view cannot withstand the test of Scripture (Revelation 4:11). Rather, the God of the Bible commonly reveals Himself through creation (Romans 1:20) and through His Word (2 Timothy 3:16) while simultaneously remaining distinct from His created beings (Isaiah 40:25-26).
Aquinas’ understanding of the Trinity has rightly been upheld for centuries past because of its ability to pass the test of Scripture. In fact, instead of simply surviving under the test of Scripture, Aquinas’ Trinitarian doctrine is bound by Scripture, succeeding within it. For the Christian, the cruciality of understanding the Trinity is based upon the cruciality of understanding the Bible. However, despite the adoption of the Nicene Creed and historic churches testing and then readily accepting Aquinas’ findings, opponents to Aquinian Trinity doctrine continue to arise. McCabes article “Aquinas on the Trinity” questions not only Aquinas’ stance on the incomprehensible but also a Biblical stance of God. His issues lie in accepting abstractness. However, after thoroughly examining the Scriptures, it is not only necessary for the Christian to embrace God’s abstract character, but it is also good for the Christian to embrace the incomprehensible. The revelation of God’s triune character through creation, the Old Testament, the New Testament, and beyond is evident throughout the summation of Scripture. Incontestably, the doctrine of the Trinity is good, necessary, and true.
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Duby, Steven J. “Trinity and Economy in Thomas Aquinas.” The Southern Baptist Journal of Theology, vol. 21, no. 2, 2017, pp. 29-51, https://equip.sbts.edu/publications/journals/journal-of-theology/trinity-economy-thomas-aquinas/, accessed 21 January 2020.
Fesko, J.V. “The New Adventures of Old Trinitarian Heresies.” Tabletalk, Dec. 2019, pp. 23-25.
Mathison, Keith A. “Is the Trinity Biblical?” Tabletalk, Dec. 2019, pp. 5-7.
McCabe, Herbert. “Aquinas on the Trinity.” Angelicum, vol. 78, no. 4, 2001, pp. 535-557.
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Smith, Tyler. “5 Ways the Doctrine of the Trinity Is Surprisingly Practical.” LogosTalk. https://blog.logos.com/2016/03/5-ways-the-doctrine-of-the-trinity-is-surprisinglypractical/. Accessed 28 February 2020.
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