God acts. God is known by his acts. Few theological propositions are more foundational to Christian theology and theological method than these two.
The modern “revival” of trinitarian theology relied on a version of these two propositions in its quest to discover the so-called “immanent Trinity” by means of the “economic Trinity.” That quest has proven unsatisfying, not only because it generated so many competing conceptions of the Trinity but also because so few of those conceptions bore much resemblance to the church’s historic confession of the Trinity in the Nicene Creed.
More recent theology, for the most part, has moved beyond this modern quest by retrieving principles of Nicene trinitarian theology. Retrieving these principles has helped us better appreciate the distinction between divine processions and divine missions, the nature of inseparable operations, as well as the relationship between general and special revelation, natural and revealed theology. In retrieving these principles, recent theology has provided a more promising foundation for the Christian doctrine of God than did the modern quest.
My sense, however, is that something is still missing. Bad intellectual habits are hard to unlearn. Superficial similarities between modern trinitarian theology and Nicene trinitarian theology make it easy to miss more substantial dissimilarities. In addition to the principles of Nicene trinitarian theology mentioned above, I suggest that theology also needs to rehabilitate the conception of action that underlies a Nicene understanding of how God acts and how God is known by his acts if we are to appreciate more fully how Nicaea’s central Christological insight—that the Son is “begotten, not made”—might inform theology today.
An underlying conception of action
If we are to grasp a Nicene understanding of how God acts and how God is known by God’s acts, we must first come to grips with the basic conception of action that this understanding presupposes. This conception of action, though confirmed in Scripture, is broadly discernible in nature as well and was, for that reason, recognized in certain strands of ancient philosophy.
According to this conception of action, certain kinds of causes produce certain kinds of effects. Fig trees bear figs; grapevines produce grapes; freshwater springs produce fresh water (James 3:12). The reason for this is that certain kinds of powers are native to certain kinds of causes.
An epistemological corollary follows, namely, that certain kinds of effects are signs of certain kinds of causes. “Each tree is known by its own fruit” (Luke 6:44).
We assume some such conception of action in our everyday experience. If we come home to find a clean house, we ask, “Who did this?” If we come home and discover that a tree has fallen on our roof, we ask, “What happened here?” The different pronouns we use in these different situations reflect our natural tendency to take different sorts of effects as evidence of different sorts of causes.
Many causes have more than one kind of power that enables them to produce more than one kind of effect. A man, for example, may beget a son (the fruit of his reproductive power) or build a house (the fruit of his rational power). Though a man’s reproductive powers are analogous to those of other animals, they are nevertheless specific to the kind of animal he is. A man fathers another human being, not a puppy (Gen 1:12, 21, 24, 25; 5:3). The same goes for his other capacities. We should expect that a dam built by a human being will look different from a dam constructed by a beaver.
A second epistemological corollary follows from the preceding point. According to this conception of action, some degree of resemblance always obtains between causes and effects because causes prepossess the perfections displayed in their effects. Moreover, the degree of resemblance that obtains between a cause and its effect is determined by the kind of power that is operative in a cause’s production of its effect.
When a father begets a son, the resemblance is “formal.” Human beings beget human beings. A son is the same kind of thing that his father is.
When a man builds a house, however, the resemblance is more distant. A house will reflect some degree of its builder’s wisdom, skill, goodness, and strength. But a house is not the same kind of thing that its builder is (i.e., it’s not his child, whatever he may call it!). The builder possesses the perfections exhibited in the house “virtually” (i.e., in his architectural powers) rather than “formally.” Moreover, though a house reflects something of its builder’s wisdom, skill, etc., a house does not exhaust those perfections. The builder possesses the perfections exhibited in the house “eminently” (i.e., to a higher degree).
The distinction between divine begetting and divine making
The conception of action summarized above underlies the pro-Nicene distinction between divine begetting and divine making and that distinction’s numerous theological applications.
According to Scripture, creation is the product of God’s supreme wisdom, goodness, and power (Genesis 1; Ps 33:6-9; Jer 10:12; Rom 11:33-36; Rev 4:11). For this reason, Basil of Caesarea confesses, “An intelligent cause presided at the birth of the Universe.” As the product of divine wisdom, goodness, and power, creation teaches us something about its Creator. Commenting on Genesis 1 and Romans 1:20, Basil states, “the world was not conceived by chance and without reason, but for an useful end and for the great advantage of all beings, since it is really the school where reasonable souls exercise themselves, the training ground where they learn to know God; since by the sight of visible and sensible things the mind is led, as by a hand, to the contemplation of invisible things.” The created effect, by divine design, leads us to a knowledge of the divine cause.
Because it is the product of divine making, however, creation bears only a distant resemblance to its divine cause, who far transcends creation’s wisdom, beauty, goodness, and power. Basil explains the significance of the verb Genesis 1:1 uses (i.e., “created”) to describe God as the transcendent cause of the cosmos: “he adds ‘Created’ to show that which was made was a very small part of the power of the Creator. In the same way that the potter, after having made with equal pains a great number of vessels, has not exhausted either his art or his talent; thus the Maker of the Universe, whose creative power, far from being bounded by one world, could extend to the infinite, needed only the impulse of his will to bring the immensities of the visible world into being.”
Elsewhere, Basil develops a similar argument in response to Eunomius’ claim that the Son is a creature, a claim the latter roots in his interpretation of the names of the Father and the Son. According to Eunomius, the different names of the Son (“only-begotten”) and the Father (“unbegotten”) signify their different ontological status. “Only-begotten” signifies the Son’s status as created effect. “Unbegotten” signifies the Father’s status as divine cause.
Basil disputes Eunomius’ interpretation of divine names on several grounds. Never mind that “unbegotten” tells us only what the Father is not rather than what he is, if the “only-begotten” is a created effect, then he bears only a distant similarity to his “unbegotten” divine cause and, therefore, he cannot possibly reveal that cause’s being or substance. “How is it possible,” he asks, “to reason back from created works to substance? This is something which I for my part fail to see. For things which have been made are indicative of power and wisdom and skill, but not of the substance itself. Furthermore, they do not even necessarily communicate the entire power of the creator, seeing that the artisan can at times not put his entire strength into his activities; rather, he frequently attenuates his exertions for the production of his art. But if he were to set his whole power into motion for his product, even in this case it would be his strength that could be measured by means of his products, not his substance that could be comprehended, whatever it may be.”
According to Basil, the Son can reveal the Father’s substance only if he is the product of divine begetting rather than the product of divine making. Drawing on the conception of action outlined above, Basil explains: “it is not the from the products of the artisan that we comprehend the artisan’s substance, but … from that which has been begotten that we come to know the nature of the begetter. After all, it is impossible to comprehend the substance of the housebuilder from the house. But on the basis of that which is begotten it is easy to conceive of the nature of the begetter.” “Consequently,” he concludes, “if the Only-Begotten is a created work, he does not communicate to us the substance of the Father. But if he makes the Father known to us through himself, he is not a created work but rather the true Son, the image of God [Col 1:15], and the character of his subsistence [Heb 1:3].”
Because the Son is the product of divine begetting rather than the product of divine making, he shares the Father’s substance. As one who shares the Father’s substance, the Son is able to reveal the Father’s substance as well.
In addition to the way it informs his understanding of divine revelation in its various modes, Basil’s understanding of the distinction between divine making and divine begetting also informs his understanding of the Son’s creating and saving work. According to Basil, by virtue of divine begetting, the Son not only shares the Father’s substance, he also shares the Father’s power and performs the Father’s works: “For if he is without difference in substance, he will also be without difference in power, and for those whose power is identical, the energy also is wholly identical.”
Cyril of Alexandria displays a similar pattern of biblical reasoning in his commentary on John 5:17-19. In John 5:17, Jesus defends his work of healing on the Sabbath by connecting his person and work to the person and work of the Father: “My Father is working until now, and I am working.” Jesus’ work of Sabbath healing, in essence, is a matter of engaging in the family business. Jesus’ Jewish opponents infer from his defense that he is claiming to be the Father’s natural-born Son, thereby “making himself equal with God” (John 5:18). According to Cyril, Jesus’ opponents have understood the logic of his claim correctly. If, as Jesus claims, God is “his own Father,” then Jesus “must be equal to him by nature.” Moreover, if the Father and the Son “have the same nature as each other,” Cyril reasons, then they must also be “equal … in power” and “act in the same way.” “For things that have the same nature as each other will act in the same way. But those whose mode of being is different would not have the same way of doing everything.” By virtue of divine begetting, the Son shares the Father’s substance, power, and works, which is precisely what Jesus argues in the verses that follow (John 5:20-30).
The distinction between divine begetting and divine making, and the underlying conception of action that informs it, is a key element in pro-Nicene understandings of how God acts and how God is known by his acts. Before wrapping things up, it is worth noting one further, specifically cosmological application of this distinction. By locating the Son (and the Spirit) on the divine side of the distinction between divine cause and creaturely effect, theologians like Basil and Cyril undermined the tiered cosmologies taught by Eunomius along with many Neoplatonic thinkers. According to such tiered cosmologies, the one God presided at the highest sphere of being, power, and causality, his relation to the rest of the cosmos being “buffered” by the intermediary agencies of a (created) Logos, and below that, a (created) World Soul. Contrary to such teaching, however, pro-Nicene teaching regarding the consubstantiality of the Son and the Spirit confirms and reinforces the biblical view that “there are two realities, creation and divinity.” At a later stage in the development of this line of trinitarian cosmological thinking, Maximus the Confessor will further dismantle the tiered cosmology of Neoplatonism by affirming the immediacy of the triune cause to all created effects.
 Lewis Ayres, following Michel Barnes, cites the example of Plotinus, Ennead, 5.4 (Lewis Ayres, Nicaea and its Legacy: An Approach to Fourth-Century Trinitarian Theology [Oxford: OUP, 2004], 353).
 Basil of Caesarea, Hexaëmeron, Homily 1, p. 16.
 Basil, Hexaëmeron, Homily 1, p. 22.
 Basil, Hexaëmeron, Homily 1, p. 30.
 Basil, Hexaëmeron, Homily 1, p. 17.
 Basil, Against Eunomius, 1.10-11, p. 105-107.
 Basil, Against Eunomius, 2.32, p. 180.
 Basil, Against Eunomius, 2.32, p. 181.
 Basil, Against Eunomius, 2.32, p. 181. NB: I have corrected the scripture allusions in The Fathers of the Church translation.
 Basil, On the Holy Spirit, 8.19, p. 49-50.
 Cyril of Alexandria, Commentary on John, 1:142.
 Cyril of Alexandria, Commentary on John, 1:143.
 Cyril of Alexandria, Commentary on John 1:143.
 Basil, Against Eunomius, 2.31, p. 178; 3.1-2, p. 185-88. Compare with Cyril of Alexandria, Against Julian, 8.26.
 See Maximos Constas, “Maximus the Confessor, Dionysius the Areopagite, and the Transformation of Christian Neoplatonism,” Analogia 2 (2017): 1-12.