Bob: How can an immaterial God interact with a material universe?
Alice: The question itself needs to be questioned before we can answer it.
Bob: How so? It seems like a fairly straightforward question.
Alice: Well, consider the word “interact.” God does not interact with anything. To interact requires action going in both directions, and since God is pure actuality this is impossible. Rather God acts on and through creatures without them acting on him.
Bob: Ok, so we’ll change the question to how an immaterial God can act on or through a material creature.
Alice: It’s better but still has problems. When you ask “how” God can act, what type of answer are you expecting?
Bob: I’m not sure I lay out exactly the type of answering I’m looking for, but I can give you illustrative examples. Fire heats by inducing mean molecular motion, I pick up things with my hands, and one stone acts on another by knocking into it. In each of these cases, I can point to the means or process by which some action is performed by one thing on another.
Alice: But on that account, the question is loaded! In each case, you could give some organ, part, or some material property by which one thing causes something in another thing. None of these kinds of answers apply to God since he has no organs, parts, or material properties. And to assume this in the question at hand is to preclude the possibility of giving an answer.
Bob: I grant your point but how, then, am I to proceed? Surely there’s a legitimate question to be asked here? And if we can’t use physical categories to have the conversation, then what can we use? After all, surely all our knowledge comes from our experiences of physical things?
Alice: It is true that all human cognition starts with sense data. But through abstraction and other intellective acts, we can move beyond these data, so that while our knowledge starts with our experiences it needn’t end with them. We do this, for example, when studying infinities in mathematics or when picking out idealized models in physics. Even in imagining things that don’t really exist, like fictional characters and stories, we are moving beyond what we have experienced. I agree that there is a legitimate question to be asked, but my point is that it should not be understood as a physical question but as a meta-physical one.
Bob: Ok, granted that the question — and therefore answer — is metaphysical, how would you answer?
Alice: One of the broadest distinctions we have in metaphysics is that between act and potency. Just as we’ve been saying, we come to understand this distinction through everyday phenomena like change and multiplicity. And once we understand act and potency, we can then move beyond these phenomena to talk about things beyond our everyday experience, like God. It is with categories such as these that we need to approach the question.
Bob: I understand the distinction between act and potency, and I understand that God is conceived of as a being of pure actuality. But how does this distinction answer the question?
Alice: It doesn’t by itself answer the question. But it is the first step in showing that the question is, in a way, misplaced.
Bob: I don’t see how it could be misplaced. After all, it seems quite natural to ask how a thing without arms or legs could act on material things.
Alice: Let me explain. Once we arrive at the distinction between act and potency we can draw out various corollaries, two of which interest us here. First, things act only insofar as they are in act. The basic idea behind this is that acting on something involves actualizing potentials in that thing, and since potency cannot actualize anything this can only happen insofar as the thing acting is in act. Second, potency limits act. When an act is understood as the actualization of this or that potency, it becomes qualified (or limited) by that potency. For example, the act of mean molecular motion is of itself not limited to a time or place or speed, but when it comes to actualize the potencies in something being heated then it will be limited in these ways.
Bob: I don’t see how all of this relates to the question. How do either of these help us find the metaphysical hand by which God acts on a material thing?
Alice: The point is that he doesn’t need such a hand in the first place! As material beings, we exist through the actualization of potencies in our matter. As such, our actions are limited in various ways, which is why we cause by means of organs, parts, tools, contact, etc. A particular fire can’t heat something across the world because it’s limited by its matter to a specific place and time. A particular stone can’t simply make another move whenever, but has to collide with it, because its causal influence is limited to where and when it is.
Bob: And what about God?
Alice: As we’ve said, God is pure actuality, which is to say that there is no potency in him that limits his action. He simply brings about his effects immediately, without any need for the various means we need as material beings. This is why I said the question is misplaced. If anything is surprising it’s that we limited beings can interact with each other, not that the unlimited God can act on us.
Bob: That may be evident upon later metaphysical reflection, but I think the question arises quite naturally from our everyday experience of how things interact with one another. After seeing that things typically interact by various means that depend on their materiality, we quite reasonably ask how it is that an immaterial God could do something similar.
Alice: That’s a fair point. The answer, then, is that an immaterial God does not do something similar. He does not interact, but rather he acts. And he does not act by means of something, but rather he acts immediately. His action is similar to ours in that it arises from him being in act, but it is different from ours in that his being in act is not limited by any potencies within himself.
Bob: I see. In a way, it is almost an inevitable consequence of his being the creator of everything. If he needed a means by which to act, then this means could not have been created by him.