The popularity of the recent television series The Queen’s Gambit got me thinking about chess. Well, not about chess actually, about which I know shamefully little, but rather about how the game of chess might be used to metaphorically elaborate one of the most crucial truths of theistic metaphysics: the analogical nature of causality. This doctrine recognizes that events are caused both by God and by creatures working cooperatively to bring about change in the world. The simultaneous causality of God and creatures is possible because their activity does not compete or conflict with one another, but each acts as a cause in different ways. That is why we must refer to their causal activity as analogical: they are both truly causes, but nevertheless different in kind from one another. This teaching is crucial for Christians because it is the key to answering a plethora of philosophical and theological puzzles, including perennial issues like the problem of evil, the relation between God’s creative foreknowledge and human free will, and the necessary cooperation of nature and grace. For in each of these, if we fail to accept the analogical nature of their causal activity, then only one side can act to the exclusion of the other. Either God’s action overwhelms the action of creatures, eliminating human freedom and making God the cause of evil, or the activity of creatures leaves no room for divine activity, and we are left with the mechanistic universe of scientific determinism in which human freedom is inadmissible and evil triumphant. In order to make all this clear, let me return to chess.
I must preface this with a caveat about the use of metaphorical expositions, such as my use of chess here. First, this does not pretend to be rigorously argued. The metaphor is meant to communicate a more abstruse reality through comparison with a more common experience. It is not an argument to demonstrate that truth. (I will, however, note where one might find rigorous demonstrations of these claims.) Second, some might find any given metaphorical exposition unhelpful, for any number of reasons. If you do not find this helpful, leave it and move on. I hope, though, that some might find this of use in coming to terms with the relation of creatures to God.
The first thing everyone learns about chess is that each of the pieces moves in a very particular way. Pawns move only one space vertically at a time (though their initial move may be two spaces and they attack on a diagonal); rooks move an indefinite number of spaces, but only vertically and horizontally; bishops move on diagonals; knights in an “L” shape; kings and queens move in any direction, but the former only one space and the latter an indefinite number of spaces.
The point of this primer is to note a basic fact of creation. The first thing we know about the natural world is that every individual is understood in terms of what kind of thing it is. That is, every individual is an instance of some nature. It is the nature that defines what that individual is, uniting certain things together and distinguishing them from every other nature. Thus, each of the elements on the periodic table, every species of plant, all the species of animals are all known to be different natures. Furthermore, like chess pieces, what something is determines how it can move. That is, each nature is associated with a characteristic way of acting in the world; indeed, it can be said that, like chess pieces, natures exist for the sake of their particular activity. Hydrogen atoms form chemical bonds in a way indicative of hydrogen, and unlike any of the other elements; water molecules will freeze and boil at a particular temperature, and interact with other substances according to its unique constitution. Apple trees grow apples, and orange trees grow oranges. Antelopes graze on the savannah while the lion hunts them. And man alone creates art and worships God. One significant difference here is that while there are only six kinds of chess pieces, there are a vast number of natures; the reason for this is that God, in creating, aims to share His infinite goodness, which can only be manifested through this multitude of distinctively acting natures.
This aspect of my metaphor is to illustrate how the action of natures in the world is just as regular as that of the chess pieces. Just as a rook cannot move on a diagonal, so an apple tree will never grow oranges. In fact, just as you can tell a chess piece by the kind of moves it makes, you can determine the nature of each thing by its activities. This fact is epitomized in the dictum agere sequitur esse—action follows from being. Accepting this principle is the prerequisite for there being any intelligible order in the world. Our world is a world of activity and change; yet, despite this constant state of flux, there are underlying patterns of activity—discernible and predictable patterns—which reveal the natures of those things which are acting. This intelligible order of creation is like the rules of a chess game. Imagine a chess game where any piece can move in any way; not only would it be chaos, it would not be a playable game at all. In the same way, if things did not act according to their specific natures, if any being could do anything, then the universe would be, as William James suggested, a booming buzzing confusion. The bread that was nutritious yesterday might be poisonous today; the harmless bunny I saw yesterday might be murderous today; yesterday’s bountiful apple tree might now produce Big Macs. In a world without rules, anything is possible, but only because nothing is expected. If this were the case, we could never gain meaningful knowledge of creation, resulting in a complete paralysis of uncertainty.
From this it is clear that the natures must play a crucial role in causing events in the world. Each nature acts according to an intelligible pattern, and this allows for the development of the various sciences: physics about material forces, chemistry about elemental reactions, biology about natural patterns of life, and so forth. Just as chess makes sense only if the pieces follow the rules, nature makes sense only if creatures act according to the physical laws known by the natural sciences.
Yet here we need to return to a basic fact about chess: no chess piece ever moves itself. While each piece carries within itself the potential to move in a determinate way, the actual movement depends on a player to move them. Moreover, that player moves them not capriciously but with the intention to win the game. This higher cause—the ultimate cause of motion and of the overall order of all movements—can be seen as a metaphor for God’s activity as the primary cause of creatures.
The first point here is that creatures—like chess pieces—are characterized by an inherent potential to act, but this potential needs to be brought into activity by something else. This is the familiar argument of God’s existence is demonstrable as the first cause of motion in the world, an argument invoked by pagans and Christians alike. Because no chess piece can ever move itself, the explanation for the movement of pieces can never come from within the chessboard, so to speak: even if a piece is said to move “in reaction to” another piece’s movement, you would need to explain that prior movement. We can see that here must be a cause of movement prior to and independent of any motion within the context of the game itself.
Thus, on the one hand, it is true that the game is indeed self-contained and each move can be interpreted as a reaction to another move. On the other hand, though, the entirety of the movements of the game point ineluctably to something outside the game. In this, our metaphor illustrates the relation between science and metaphysics. The self-contained and deterministic movement of pieces represents science: natures cause change in the world according to a regular and predictable pattern of action described by science. Yet, natures are only secondary causes, because they depend on a primary cause for the very existence of their activity. The fact that there is anything happening at all—that the potential for movement comes to fruition—points to God as the first cause, known not by science but by grasping the ultimate cause of being in metaphysics.
This complementarity between the regular activity of the pieces and the creative activity of the player exemplifies what we mean by “analogical causality.” Both the pieces and the player are responsible for the moves on the chessboard, but simultaneously and in different ways. The nature of the piece determines what sort of move will happen. But the player decides if the move will happen at all. We can say, then, that the player determines the actuality of the move by making it real, while the piece will nevertheless only move according to how it is capable of moving. In this way, both the player and the piece determine what will happen in the course of the game.
The relationship of creatures to God must always be considered according to this principle of analogy. Creatures exist as instances of a finite nature which can only act as causes in certain determinate ways. Yet their very reality—and their ability to act at all—depends on God making them real. Both creature and God need to be active in causing what happens in the universe. An apple tree grows apples because that is what apple trees do; yet the apple tree only exists and acts because God makes it to be an apple tree.
Some may object that this cooperative causality in some way detracts from the glory of God, who as omnipotent Creator can do everything on His own. While God can indeed do everything on His own, it is important to see that His omnipotence and goodness are actually better manifested in his generosity in sharing causal responsibility with His creatures. God does not need creatures; rather, he creates simply out of a gratuitous desire to share his perfect goodness. But it is the essence of God’s goodness to be a cause of goodness in others, and that is the power he shares with creatures. Thus, God gives to creatures the ability to be real causes in the order of nature according to their own unique perfections: water does give hydration to plants, apple trees really do grow fruit, and man really does illuminate the world with love and wisdom. The creature determines the specific nature of the perfective activity. Nevertheless, none of these things cause themselves; they are always dependent on God constituting the very existence of that activity.
We can grasp the necessity of this shared responsibility of analogical causality if we contrast it to a univocal vision of causality. In this vision, all causes operate in the same way. Accordingly, either God is acting or a creature is acting, but never can both act together since they would conflict with one another. This is why univocal causality is prominent in the fundamentalisms of both science and religion. As John Rist has perceptively noted, fundamentalists are interested only in their “saving truth” and are indifferent to truth per se. They will reduce all causality to the one area that they find most important. Hence, if there is only one cause for every event, the scientist will naturally acknowledge only the acts of nature to the exclusion of God; the believer would acknowledge only God’s activity to the exclusion of nature. But the first leaves us with a mechanistic universe where things act without any intelligible purposes—we know how things happen, but never why; the second leaves us with creatures who are not truly independent of God, making the act of creation utterly superfluous. The only way to give due credit to the dignity of both God and creatures, the only way that grasps the whole truth about God lovingly sharing His goodness with creation, is to accept the analogical nature of causality. To re-cast the Gospel of John, “For God so loved the world that he allows creatures to share in His causal activity….”
We can extend this chess metaphor to grasp some more truths of philosophical theology. First, we can see why so many who easily accept science are at the same time reluctant to accept the existence of God. In a game of chess, the movement of the pieces is determinate and obvious to any observer. Seeing what a knight or a queen does is easy. However, coming to know the personality of a player is much more difficult—though, with time and effort, not impossible. In the same way, the scientific facts of nature are evident to our senses, and can be spontaneously known if we attend to nature. The truth about God as the first cause of nature as a whole is much more difficult. Indeed, we can only be certain that he must exist as a cause, but we can never fully grasp his nature since we know him (in this world) only by means of creation.
Nevertheless, just as you can know something about a chess player without knowing her intimately, we can, by considering creation, identify some of God’s essential properties. We have argued that God is responsible for the existence of all the movements of creatures; but, following the principle that action follows from being, to be the source of existence means that God must be existence itself. So, just as the chess player is utterly different in kind from any mere chess piece, so God, unlike any creature, is not a kind of being; rather, he is simply the infinite act of existing itself. As such, God is responsible for the existence of all things, since existence is the cause of actuality for all acts, and the cause of perfection for all perfections.
This, of course, stretches our chess metaphor. God is not only like the player who moves pieces; he is responsible for the existence of the game itself: he makes the board and the pieces and the rules of the game. This point eliminates one of the more problematic limits of our chess metaphor. Chess normally involves two players moving pieces, which is a good explanation about why the game is about conflict. Indeed, many have postulated the existence of two competing divinities to account for the reality of conflict in the world. This is the ancient heresy of Manicheanism. Against this, our metaphor would insist that God alone creates the board, the pieces, and the rules, and he alone moves the pieces. This, though, brings us directly to the puzzle about why there is conflict in the world. But it is precisely here, concerning the problem of evil, that our metaphor about analogical causality might prove most helpful. Let us consider this in two steps.
First, in a game of chess involving experienced players, it is obvious that all the moves are done for the sake of making it the best game possible, for thoughtless moves undermine the very point of playing the game. In the same way, we can know that God, who causes all the movement in the universe, does so in order to make this universe as good as it can be. We can be confident, then, that what happens is neither utterly haphazard nor mechanically deterministic—both of which would eviscerate human life of meaning—but rather is intelligently ordered for the sake of some good. Nonetheless, just as a chess game can only be as good as the pieces allow, in the same way, the perfection of the universe cannot be seen according to some abstract, a priori criterion; on the contrary, it is wholly in accord with the nature of the creatures that God has created. Every universe God could have created is perfect in a different way. This universe has its own mode of perfection, reflecting the creatures that God chose to be his causal agents. For this reason, we cannot allow our wishes for other worlds to obscure the goodness of the reality with which God has gifted us.
Yet to assert that the universe is ordered to perfection immediately brings the reasonable objection about the presence of evil and suffering in creation. Here again our chess metaphor is illuminating. While every move in a chess game aims to make it the best game possible, pieces inevitably come into conflict: a pawn occupying a space invaded by a bishop will be sacrificed. As the game progresses, in order for each piece to move according to its nature, and for the game to move to its consummation, some pieces must be lost. Yet the goal of all these moves, entailing all these losses, is the best game as intended by the player.
So it is in the order of creation. Because there is a great diversity of natures, each moving in its own way, some will come into conflict with others. An antelope grazing might be sacrificed to a lion; an apple tree might be sacrificed to an infestation of mold; a person might suffer because of a virus. While God desires the perfection of the universe, any given individual might have to suffer as a concomitant to the flourishing of a different creature, for it is only in this way that the universe can attain perfection. This is the nature of natural evils, which are built into the providential order of creation. While natural evils are always tragic for the creature who suffers—the antelope who becomes prey, the tree which is infested, the person who falls ill—we can take consolation that in some way God has allowed this for the overall perfection of the universe. This sort of evil is unavoidable, for lions with all their terrible ferocity can only survive by hunting antelope. The perfective activity of some creatures entails that other creatures might be deprived of theirs.
These examples—both in chess and in nature—highlight another critical truth: that evil must be understood as a creature’s loss of being and not as some reality created by God. In chess, it is inevitable that one piece will take another. Similarly, in nature evil is a privation of being suffered by one creature as a result of its coming into conflict with another. As such, evil is a fact about nature, not about God. Just as a chess player will sacrifice a pawn to gain checkmate, so God allows for these evils but only for the sake of the ultimate perfection of creation.
However, this is not the whole story. There is, of course, another kind of evil: moral evil. This arises not when one creature succeeds at the expense of another. Rather, this is man acting freely and choosing not to succeed at all. Let us return to the chess board to see how we might explain this.
Like a player moving pieces on the board, God moves all creatures for the sake of the perfection of the universe. Since most creatures act purely instinctually, they passively obey this providential ordering to the good. As a result, they only suffer evil when they come into conflict with other creatures, who are also directed by God to their perfection. Man, though, has free will. Like all creatures, he is moved by God to attain the perfection for which he exists; this direction to our perfection is reflected in the precepts of the natural law, which are derived from the inclinations God has instilled in us by virtue of our human nature. But because man is free, he can refuse to be moved by God. Imagine a chess player whose knight, for some reason, is stuck on the board and will not move. This disrupts not only the good operation of the knight, but throws the whole game into confusion. This is the vitiating nature of moral evil: while man’s wisdom ought to direct him to act in accord with providence for the perfection of the universe, he can perversely use free will to refuse this movement to the good. This act of free will introduces disorder into the whole of creation since it is disrupting not only the good of the person but also the order of the entire universe as created by God. This act of refusing movement epitomizes evil as a privation of being, since man is introducing a lack of action. Furthermore, because moral evil—unlike natural evil—reflect no perfective action at all, it is pure privation. Thus, moral evil, as a defiance both of God’s movement and our natural inclination to move, is the greatest evil.
We can now see how the analogical causality of chess pieces and chess player also acts as a metaphor for how free will can exist alongside God’s omnipotence and providence. Just as chess pieces exist to move in a specific way, God creates each creature to act in the way it was created to act. For this reason, God allows free creatures to act freely. This means that sometimes human freedom will oppose the movement of God to the good. Of course, God knows this: he allows for free will to choose to be defective and not perfective. But in this case, it is man who is responsible for the evil, for it is his act of free will that brings about the harm.
Once again we see the limits of our metaphor, as another disanalogy with chess shows. Unlike our hapless chess player whose knight is stuck in place, God can override the defectiveness of creatures and bring about some perfection even when they are not acting as they should. This is what we mean by miracles: when God, as the primary cause of all that is, acts directly in his created order to bring about an effect without the nature acting as it usually does. This is important because, contrary to some common objections, God is neither “interfering” in the world, nor acting against the law of nature. A miracle is not like a devious player moving a knight like a queen. People who think otherwise ignore the analogical nature of causality, for it is obvious that God’s causality is not restricted like that of creatures. Since creatures only act because they are made by God, God is always present in the world and so he is perfectly able to act directly himself. Nor must a miracle be some oddity that is utterly outside the realm of experience. Rather, a miracle is defined not by what happens, but by that by which it happens: when God directly brings about an effect at the level of secondary causality. Consequently, once we understand the nature of God’s omnipresence in the world, we understand that the opportunity to witness to the miraculous is ever-present.
The same reasoning allows us to extend the relation between God and nature as analogical causes from philosophy into theology as an explanation for the working of grace. Even here, the great error—as evidenced in the thought of Luther—is to assume that nature and grace are univocal causes, so only one may act to the exclusion of the other. Accordingly, Luther assumes that God’s irresistible grace explains salvation, leaving no role for human nature to play. In fact, grace and nature are not in competition. God offers grace, but human nature must freely cooperate in accepting it. This is the only way to make sense of the sacramental economy of salvation.
Just as a chess piece can only do what it can do, each person is created by God to move in a certain way. The challenge, in both ethics and spirituality, is to freely accept God’s direction, to not introduce a privation of perfective movement into creation. This cooperation minimizes neither God’s causality, nor man’s: our responsibility is ultimately to act in accord with the movement of God “in whom we live and move and have our being” (Acts 17:28).
 ST I.105.5.
 ST I.47.1.
 ST I.77.1.ad 7.
 Aristotle, Metaphysics XII.6-9.
 ST I.2.3.
 Although the Thomistic argument is better read as being about synchronic ontological dependence on a first cause, since the order of creation can in fact be eternal (see ST I.46.1-2), the metaphor lends itself more easily to this diachronic dependence, though it also implies—as we will see—the synchronic causality Thomas prefers.
 ST I.13.5.
 SCG III.97.17.
 ST I.22.3 and I.103.6.
 John Rist, What is a Person? Realities, Constructs, Illusions (Cambridge: Cambridge University Press, 2020), 145.
 ST I.2.2.
 ST I.3.4 and I.65.1.
 De Potentia 7.2.ad 9.
 ST I.11.3 and I.22.2 (corpus and ad 2).
 ST I.25.6.ad 3.
 ST I.48.1-5.
 ST I.48.5-6.
 ST I-II.94.2.
 ST I-II.91.2.
 ST I.49.2.
 ST I.14.13, I.19.8, I.22.4.
 ST I.48.2.
 ST I.105.6-7.
 Charles Morerod, OP, Ecumenism and Philosophy: Philosophical Questions for a Renewal of Dialogue (Ave Maria, FL: Sapentia Press, 2006).
 This is true even when we affirm that, in contradiction to the accusation of semi-pelagianism, the first impetus to salvation comes from grace itself; see ST I-II.109.6.