Our Minds as a Model

Trinitarian analogies have acquired a rather negative reputation within many Christian circles. This negative reputation is not without reason, for most of the analogies intended to illustrate the Trinity have, at best, resulted in significant doctrinal distortion and, at worst, in outright heresy.^[1] Nevertheless, such caution has often led many to overlook a Trinitarian analogy that bears the imprimatur divinum (divine approval).^[2]

Thomas Aquinas used the psychological analogy (PA) to elucidate the doctrine of the Trinity in his treatment of the eternal processions. It is named “psychological” insofar as it is grounded in the operations of the human psyche.^[3] For Aquinas, “the psychological [analogical] model became the favored way of describing the distinction between the persons.”^[4]

Should Protestants seek to recover this analogy? The present article aims to introduce readers to the psychological analogical model as a constructive theological resource for deepening reflection on the Trinity. More specifically, it endeavors to recover the model as articulated by Aquinas, who remains, in the author’s judgement, its most precise and authoritative exponent.^[5] To this end, the discussion is structured around four guiding questions: What is the PA according to Aquinas? Why should it be employed? What is its biblical foundation? And what are the benefits of retrieving it?

What is the PA? Defining terms

All our language concerning God is therefore analogical—never univocal, nor purely equivocal, but properly analogical. Share on XAnalogy. The concept of analogy in Aquinas is both intricate and highly debated among scholars.^[6] According to the Fourth Lateran Council of 1215, analogy is defined as similitudo in maiore dissimilitudine, that is, “…between creator and creature there can be noted no similarity so great that a greater dissimilarity cannot be seen between them.”^[7]

All our language concerning God is therefore analogical—never univocal, nor purely equivocal, but properly analogical. Thus, when we ascribe “love” to both God and human beings,  a genuine likeness is acknowledged between the two. Yet, within that likeness lies an even greater dissimilarity: the love of God is not like human love (and mercifully so).

The epistemological principle and ontological reality of analogy are fundamental to the entire doctrine of God—applying not only to discussions De Deo Uno, but also De Deo Trino. For instance, even the term “person” must be understood analogically. To say that a man is a person and that there are three Persons in the Godhead, is to employ a term that indicates resemblance, but one that is surpassed ultimately by a far greater dissimilarity.^[8]

When Aquinas employs the PA in his treatment of the Trinity, say for example, in the Summa Theologiae (27-43), he does so only after first clarifying the concept of analogy in Quaestiones 12 and 13. Accordingly, this analogy denotes a similitudo in maiore dissimilitudine—a likeness marked by greater dissimilarity.

Psychological. The analogy is drawn between the human psyche and the Trinitarian processions. Put as clearly as possible: there exists a similitudo in maiore dissimilitudine between the way in which thought and will arise in the human soul and the way in which the Son and the Spirit proceed.^[9] Declan Marmion and Rik Van Nieuwenhove capture this correspondence with precision when they talk about the Son’s procession: “When we think of something, there is a kind of inner movement in our mind, and the divine procession of the Word is somewhat like this.”[10]

In this vein, it is worth recalling that “the psychological model was a major resource that theologians in the thirteenth and fourteenth centuries relied upon to clarify or explain how the persons of the Trinity could be personally distinct yet essentially identical.”^[11] The PA thus represents an effort to articulate how there can truly be three persons who are essentially one while remaining really distinct from one another given the doctrine of divine simplicity.

Why the PA Should Be Employed?

These internal acts of intellect and will in man provide an analogical framework for apprehending the processions within God. Share on XWhat is the utility of the PA? Gilles Emery, in his Trinitarian Theology of St. Thomas Aquinas, provides a lucid rationale, significance, and necessity of it. In God, there exist real relations, and, as Emery observes, “relation itself must be founded on the origin of the persons, that is, in an action giving rise to a procession.”^[12] In other words, the co-eternal persons of the Trinity are really distinct from one another, yet their distinction lies solely in their relations of origin—relations that are “founded” upon the actions that give rise to processions.

Once again, the divine Persons are distinguished solely by real relations, and real relations necessarily require a “foundation.”^[13] In God, this foundation cannot be quantitative or accidental; it must be grounded in action. However, such action cannot be external, but must instead be internal—an immanent procession.^[14] Within the created order, a fitting analogy is found in the operations of the human psyche of such kind of processions. These internal acts of intellect and will in man provide an analogical framework for apprehending the processions within God.

The PA, therefore, serves to shed light on the nature of these divine processions. As Emery notes, this approach enhances our grasp of the relations of origin and, ultimately, of the divine Persons themselves.[15]

What is its Biblical Grounding?

Human beings do not possess the prerogative to devise analogies for the divine mystery on the basis of their own imaginative constructs, however well-intentioned. By contrast, Aquinas roots the PA firmly in divine revelation.

In his Super Ioannem, Aquinas—following Augustine—derives the PA from John 1:1: “In the beginning was the Word.” He says, “Augustine sees a likeness [similitudo] of the Trinity in the soul insofar as the mind understands itself… (De Trin. 9.5. 8).”^[16] For Aquinas, the revelation of the Second Person of the Trinity as the Word constitutes the foundation for the PA. As Thomas Joseph White aptly remarks, “Aquinas is not pretending to discover this analogy [of the logos as an intellective action] since it has clear roots in the New Testament.”^[17]

The usefulness of this biblical analogy, for Aquinas, lies in the fact that it offers, within the created order, a genuine instance of an immanent and immaterial procession. In Quaestio 27, Aquinas asks: Are there processions in God? His answer is affirmative—but not in the sense conceived by Arius or Sabellius, for, as he explains “these opinions take procession as meaning an outward act.”[18] By contrast, divine processions must “be understood by way of an intelligible emanation.”[19]

In speaking of the eternal generation (the Son’s procession), Aquinas states that this generation is to be understood in analogy not to the lower creatures, but to the greater creatures and most spiritual acts, id est, intellect and will. Through his theory of the intellect, Aquinas perfects or refines Augustine’s PA says:

As God is above all things, we should understand what is said of God, not according to the mode of the lowest creatures, namely bodies, but from the similitude of the highest creatures, the intellectual substances; while even the similitudes derived from these fall short in the representation of divine objects. Procession, therefore, is not to be understood from what it is in bodies, either according to local movement or by way of a cause proceeding forth to its exterior effect, as, for instance, heat from the agent to the thing made hot. Rather it is to be understood by way of an intelligible emanation, for example, of the intelligible word which proceeds from the speaker, yet remains in him.  In that sense the Catholic Faith understands procession as existing in God. ^[20]

Accordingly, the mode of the Son’s generation is most fittingly compared to the generation of the intellect in man. As noted above, this analogy is grounded in divine revelation itself. According to Aquinas’s teaching, its essential elements can be articulated as follows:

• Just as the word is generated in the human mind and remains interior to it, so too the Word abides within God; and since God’s understanding is pure act, the Word is co-eternal with Him. Says Aquinas, “his Word is co-eternal with him, and does not come to him in course of time.”^[21]
• Moreover, just as human understanding is, in a certain sense, our very being, so too the Word shares the same essence as the Father. Aquinas explains: “the being of the word conceived within the mind (or of the intelligible species) consists in its being understood. Therefore, the same being is that of the divine Word.”^[22]
• Finally, just as the thought is distinct from the one who conceives it, so too, mutatis mutandis, the Word and the Father are another (aliud) in relation to one another. As Aquinas remarks: “The Word was God, this shows that the divine Word is not merely an intelligible species as our word is, but that it is indeed a real and subsistent being.”^[23]

This analogy teaches, at the very least, the following: (1) the Persons are really distinct, (2) the Persons are essentially equal and co-eternal; and (3) the Son and the Spirit proceed according to distinct manners, the one as Word (intellect) and the other as Love (volition).^[24]

What are the benefits of retrieving the PA?

Before outlining its contributions, it is essential to recognize that the PA also entails certain risks when its proper limits are disregarded. For example, an incorrect application of the PA can give rise to what Friedman calls the “strong version,” a tendency observable in certain Franciscan thinkers. This version, when combined with Bonaventure’s conception of emanations, resulted in a quasi-denial of divine simplicity.^[25] Nevertheless, as Friedman rightly notes, in Aquinas and within the Thomistic tradition, care was taken to preserve the PA for what it truly is: an analogy.^[26]

Why not employ and teach the analogy offered by God in order to know Him more deeply? Share on XThis is, indeed, a mere analogy; and, as such, every point of similarity entails a corresponding recognition of dissimilarity. “Our world provides no example of procession that can perfectly represent divine generation, because the Son is born in identity of substance and eternity with the Father.”[27] In his Super Ioannem, Aquinas identifies four dissimilarities between “the Word of God” and the human word.^[28] “…The psychological analogy is just that: it is a mere analogy.”[29]

Having established this, we can now proceed to consider its benefits:

• The most significant “advantage” of recovering the PA is that it honors God by taking seriously the mode He Himself has chosen to reveal Himself. Many Christians seek analogies of the Trinity in an effort to grasp the mystery more fully; why not, then, employ and teach the analogy offered by God in order to know Him more deeply?
• The PA constitutes a valuable resource for attaining a deeper understanding of the eternal relations of origin. Aquinas argues that the existence of the processions necessarily entails the existence of relations in God—“an eternal relativity.”^[30] This concept is key, not only for affirming the consubstantiality of the Trinity, but also for safeguarding their alterity and the genuine otherness of the Persons.^[31]As Protestants, we confess the relations of origin (see 2LBC 2.3); however, without a deeper analysis of the divine processions, one may ask to what extent this confession is merely trifles (tricae).
• Building on the precedent argument, a proper understanding of the PA could provide significant contributions to the contemporary debate on Eternal Functional Subordination of the Son, demonstrating why this novel proposal becomes unnecessary once the processions and eternal relations are fully accounted for.[32]
• Furthermore, the PA enhances our knowledge of the Persons of the Trinity. Protestant discourse has often focused on the titles of the Second and Third Persons of the Trinity, Son and Holy Spirit, respectively. Aquinas, however, reminds us through the PA that the titles “Verbum” and “Caritas” are equally important and enriching for our understanding of the Second and Third Persons.
• It is the author’s hypothesis that the PA may likewise serve to reinforce the doctrine of the filioque. It is noteworthy that the Greek Church does not employ the PA—and it is precisely this tradition which stands in opposition to the filioque Might there be a connection between these two facts? If the Spirit proceeds analogically as the will-love, therefore, it must proceed from the Father and the Son (filioque) because the will-love always operates after the intellect.

The recovery of the PA is crucial for a deeper participation in the contemplation of the divine mystery, and Aquinas serves as a trustworthy and reliable guide for such holy contemplation. Aquinas’s thought in this (and related) area(s) merits renewed attention for the benefit of the Church.[33]

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Notes:

^[1] Scott Clark offers a catalog of the different analogies and illustrations of the Trinity: R. Scott Clark, “Why Analogies and Illustrations of the Trinity Fail,” The Heidelblog, July 6, 2013, https://heidelblog.net/2013/07/why-analogies-and-illustrations-of-the-trinity-fail/ (accessed August 15, 2025).

^[2] It is important to clarify the distinction between illustrative analogies that aim to explain the mystery of the Trinity as a whole and those that seek only to address a particular aspect of the doctrine. The PA presented here belongs to the latter category.

^[3] See, Russell E. Friedman, Medieval Trinitarian Thought from Aquinas to Ockham (Cambridge: Cambridge University Press, 2010), 50.

^[4] Friedman, Medieval Trinitarian Thought, 62.

^[5] As White notes, there are several models of the PA; however, the model this article seeks to present, and recover is that of the Angelic Doctor. See Thomas Joseph White, The Trinity: On the Nature and Mystery of the One God (Washington, DC: Catholic University of America Press, 2022), 424 n. 25.

^[6] For introductions to the subject, see Thomas Joseph White, Wisdom in the Face of Modernity: A Study in Thomistic Natural Theology, 2nd ed. (Ave Maria, FL: Sapientia Press of Ave Maria University, 2016); Gregory P. Rocca, Speaking the Incomprehensible God (Washington, DC: Catholic University of America Press, 2004); Domenic D’Ettore, Analogy after Aquinas: Logical Problems, Thomistic Answers, Thomistic Ressourcement Series, no. 11 (Washington, DC: Catholic University of America Press, 2019); Joshua P. Hochschild, The Semantics of Analogy: Rereading Cajetan’s De Nominum Analogia (Notre Dame, IN: University of Notre Dame Press, 2010); Steven J. Duby, God in Himself: Scripture, Metaphysics, and the Task of Christian Theology (Downers Grove, IL: InterVarsity Press, 2019), chap. 5; Michał Paluch, “Analogical Synthesis: An Impossible Project?,” Nova et Vetera 14, no. 2 (2016): 591–608; Steven A. Long, Analogia Entis: On the Analogy of Being, Metaphysics, and the Act of Faith (Notre Dame, IN: University of Notre Dame Press, 2011); John R. Betz, Christ, the Logos of Creation: An Essay in Analogical Metaphysics (Steubenville, OH: Emmaus Academic, 2023); and Thomas Joseph White, “The Analogia Entis Controversy and Its Contemporary Significance,” in The Analogy of Being: Invention of the Antichrist or the Wisdom of God, ed. Thomas Joseph White (Grand Rapids, MI: Wm. B. Eerdmans Publishing Co., 2011).

^[7] “The Fourth Lateran Council, 1215,” Papal Encyclicals Online, https://www.papalencyclicals.net/councils/ecum12-2.htm (accessed August 15, 2025).

^[8] Thomas Aquinas, ST I, q. 29, a. 3, respondeo: “Since everything that is perfect must be attributed to God, forasmuch as His essence contains every perfection, this name person is fittingly applied to God; not, however, as it is applied to creatures, but in a more excellent way; as other names also, which, while giving them to creatures, we attribute to God; as we showed above when treating of the names of God (q. 13, a. 2).” See also, Johannes Polyander, André Rivet, Antonius Walaeus, and Anthonius Thysius, Synopsis of a Purer Theology, ed. William den Boer and Riemer A. Faber, 2 vols. (Davenant Institute, 2023), I: vii, 8–9.

^[9] See Thomas Aquinas, SCG IV, 11; ST I, q. 1, a. 1, respondeo.

[10] Declan Marmion and Rik Van Nieuwenhove, An Introduction to the Trinity (Cambridge: Cambridge University Press, 2011), 117.

^[11] Friedman, Medieval Trinitarian Thought, 3.

^[12] Gilles Emery, The Trinitarian Theology of Saint Thomas Aquinas (Oxford: Oxford University Press, 2007), 51; cf. Thomas Joseph White, Principles of Catholic Theology. Book 3: On God, Trinity, Creation, and Christ, Thomistic Ressourcement Series (Washington, DC: Catholic University of America Press, 2024), 503. Real relations distinguish from notional or mixed relations. In the doctrine of the Trinity it means that the Father, the Son and the Spirit are really hypostatically distinguishable by their processions (relation of origin), while they are the same God.

^[13] Thomas Aquinas, ST I, q. 28; SCG IV, 24.

^[14] Thomas Aquinas says, “According to the Philosopher (Metaph. V), every relation is based either on quantity, as double and half; or on action and passion, as the doer and the deed, the father and the son, the master and the servant, and the like. Now as there is no quantity in God, for He is great without quantity, as Augustine says (De Trin. I, 1), it follows that a real relation in God can be based only on action” (ST I, q. 28, a. 4, respondeo).

[15] See Emery, Trinitarian Theology of Saint Thomas Aquinas, 160. Because of space constrains this article explains the PA only through the Son’s processions, and it says very little of the Spirit’s.

^[16] Thomas Aquinas, Super Evangelium S. Ioannis Lectura, cap. 1, lect. 1, nn. 26–28, in Opera Omnia, vol. 24, ed. R. Cai (Turin: Marietti, 1952); idem, SCG IV, 11, in Opera Omnia (Rome: Commissio Leonina, 1918–); and Declan Marmion and Rik Van Nieuwenhove, An Introduction to the Trinity (Cambridge: Cambridge University Press, 2011), 117: “Aquinas’ exegesis relies on a whole array of biblical texts, mainly from John and Paul, but also from the Old Testament.”

^[17] White, The Trinity, 413; Declan Marmion and Rik Van Nieuwenhove, Introduction to the Trinity, 117: “Aquinas views the psychological model as the expression and outcome of exegetical activity which is aimed at trying to make sense of the faith as handed down, and at dispelling views that are at odds with this faith.”

The Bible is abundantly clear that the Son and the Spirit proceed (John 7:29; 15: 26). In addition to this direct language of processions, there also exists the language of missions (John 8: 26; 14: 26), which are a created effect of the eternal processions. Theology seeks to clarify this revelation, by asking: what are the processions in God?, and the PA seeks to explain this, as Emery says in , The Trinitarian Thought of St Thomas Aquinas, 52: “But, so that the affirmation of ‘processions’ in God can make some sense to us, it is necessary for us to grasp what a procession is; and we can only do that by moving on by analogy from what is better known to us, processions in our own world. Unless one does this, one can assert the existence of the divine processions, but one will not have enlightened anyone’s mind as to the meaning of such an assertion.” (See also, Matthew Levering, Scripture and Metaphysics: Aquinas and the Renewal of Trinitarian Theology (Oxford: Blackwell, 2004), 150–51.). In other words, the PA is an exercise of fides quaerens intellectum. It is the confession that, although the Trinitarian mystery is incomprehensible, it is not irrational.

[18] Aquinas, ST I, q. 1, a. 1., respondeo.

[19] Aquinas, ST I, q. 1, a. 1., respondeo.

^[20] Aquinnas, ST, 27, art. 1. Respondeo. (Emphasis added)

^[21] See Thomas Aquinas, SCG IV, 11; and Brian Davies, The Thought of Thomas Aquinas (Oxford: Clarendon Press, 1992), 195: “Something can come from me because I make it or move it in a given direction. But it can also come from me without being distinct from me. For suppose I form a concept of something. My concept comes from me insofar as it is my concept (we can speak of conceiving ideas). But it is not something outside me and it is not something that can be sent as a physical object can be sent from one place to another. It is something that remains in me.”

^[22] See Aquinas, SCG IV, 11.

^[23] See Aquinas, SCG IV, 11.

^[24] See White, The Trinity, 413.

^[25] See Friedman, Medieval Trinitarian Thought, 58; see also White, Principles of Catholic Theology. Book 3, 503.

^[26] Friedman, Medieval Trinitarian Thought, 58.

[27] Emery, The Trinitarian Theology of Thomas Aquinas, 60.

^[28] See Aquinas, Super Ioannem, cap. 1, lect. 1, nn. 26–28: “The first difference, according to Augustine, is that our word is formable before being formed; see also Aquinas… The second difference is that our word is imperfect, but the divine Word is most perfect… The third difference is that our word is not of the same nature as we; but the divine Word is of the same nature as God. And therefore it is something that subsists in the divine nature.” Cf., SCG IV, 11.

[29] Marmion and Van Nieuwenhove, Introduction to the Trinity, 117.

^[30] White, The Trinity, 425.

^[31] See Emery, Trinitarian Theology, 78–102; and Dominic Legge, The Trinitarian Christology of Saint Thomas Aquinas (Oxford: Oxford University Press, 2017), 109–11, 150–52.

[32] For the debate on the Eternal Functional Subordination, see: Michael F. Bird and Scott Harrower, eds., Trinity Without Hierarchy: Reclaiming Nicene Orthodoxy in Evangelical Theology (Grand Rapids, MI: Kregel, 2020); D. Glenn Butner Jr., The Son Who Learned Obedience: A Theological Case Against the Eternal Submission of the Son (Eugene, OR: Pickwick, 2018); Millard J. Erickson, Who’s Tampering with the Trinity? An Assessment of the Subordination Debate (Grand Rapids, MI: Kregel, 2009); Wayne Grudem, Systematic Theology: An Introduction to Biblical Doctrine, 2nd ed. (Grand Rapids, MI: Zondervan Academic, 2020); Bruce A. Ware, Father, Son, and Holy Spirit: Relationships, Roles, and Relevance (Wheaton, IL: Crossway, 2005)

[33] Much work remains to be done towards this end, and Deo volente, the present author intends to dedicate his doctoral research project to this task, with the ultimate aim of blessing the Church of Christ by deepening her understanding of the Trinitarian mystery.

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