INTRO BY JIM: Alvin Plantinga is one of the world’s most important living philosophers. He taught for many years at Calvin College and then at the University of Notre Dame. The revival of explicitly Christian philosophy over the last generation has been largely due to his influence. Toward the end of his career, he worked on issues at the intersection of science and Christian belief, culminating in his book, Where the Conflict Really Lies: Science, Religion, & Naturalism (Oxford University Press, 2011). The posts today and tomorrow are excerpted from the sections of that book having to do with divine action (used with permission from both the publisher and the author). Specifically, Plantinga questions whether there really is a problem in thinking about how God might interact with the natural world.
Religious belief in general and Christian belief in particular is committed to the belief that God acts in the world; but this belief is somehow incompatible, so some claim, with contemporary science. But why should this be a problem?
According to Christian and theistic views of God, he has created our world. He may have done it in many different ways; he may have employed many different means. However he did it, Christians and other theists believe that he has in fact done it. Furthermore, God conserves the world, sustains it in being, and God governs the world in such a way that it displays regularity and predictability.
According to Christian belief, however, it is also true that God sometimes does things differently; he sometimes deviates from the usual way in which he treats the stuff he has made. Examples would be miracles: the parting of the Red Sea, Jesus’ changing water into wine, and, towering above all, Jesus himself rising from the dead. In short, God regularly causes events in the world. Divine action of this sort is action beyond creation and conservation; we could think of it as special divine action. Many theologians, curiously enough, have thought there is a serious problem in this neighborhood. These theologians don’t object to the idea that God creates and sustains the world. It is special divine action that, from their point of view, is the problem.
But what's the problem with special divine action? Why should anyone object to it? In a word (or two): incompatibility with modern science. Modern science, they think, shows, or perhaps assumes, or presupposes, that God does not act in that way. They can’t help but think of creation as a closed continuum of cause and effect, closed to intervention or interference on the part of beings outside that continuum, including God himself. The problem, then, as these people see it, is this. Science discovers and endorses natural laws; if God did miracles or acted specially in the world, he would have to contravene these laws and miraculously intervene; and that is incompatible with science. Religion and science, therefore, are in conflict, which does not bode well for religion.
But is all this really true?
The Old Picture
These skeptics are evidently thinking in terms of classical science: Newtonian mechanics and the later physics of electricity and magnetism. This is the physics of the great conservation laws, especially as developed in the second half of the nineteenth century. And of course Newtonian mechanics and classical science have been enormously influential. But classical science, just by itself, is nowhere nearly sufficient for anti-interventionism or hands-off theology. What's really at issue, rather, is a sort of world picture suggested by classical science, endorsed by many influential eighteenth- and nineteenth-century figures, and still accepted by many theologians. Or rather, there are least two importantly different pictures here.
A. The Newtonian Picture
First, there is the Newtonian picture properly so-called. This picture represents the world (or at any rate the material universe) as a vast machine evolving or operating according to fixed laws: the laws of classical physics. We consider the universe as a whole—the material universe, anyway—as a collection including material particles and the things made of them, evolving according to the laws of classical mechanics. Theologically, the idea is that the world is a great divine mechanical artifact that runs according to the fixed laws of classical science, the laws prescribed for it by God.
But the Newtonian picture is nowhere nearly sufficient for hands-off theology. According to Newton and classical mechanics, natural laws describe how the world works when, or provided that the world is a closed (isolated) system, subject to no outside causal influence. In classical physics, the great conservation laws deduced from Newton's laws are stated for closed or isolated systems. These principles, therefore, apply to isolated or closed systems. If so, however, there is nothing in them to prevent God from changing the velocity or direction of a particle. If he did so, obviously, energy would not be conserved in the system in question; but equally obviously, that system would not be closed, in which case the principle of conservation of energy would not apply to it. Indeed, there is nothing here to prevent God from miraculously parting the Red Sea, or bringing someone back to life, or, for that matter, creating ex nihilo a full-grown horse in the middle of Times Square. It is entirely possible for God to create a full-grown horse in the middle of Times Square without violating the principle of conservation of energy. That is because the systems including the horse would not be closed or isolated.
Furthermore, it is no part of Newtonian mechanics or classical science generally to declare that the material universe is a closed system. You won’t find that claim in physics textbooks—naturally enough, because that claim isn’t physics, but a theological or metaphysical add-on. (How could this question of the causal closure of the physical universe be addressed by scientific means?) Classical science, therefore, doesn’t assert or include causal closure.
Moreover, the natural laws offer no threat to special divine action. Miracles are often thought to be problematic, in that God, if he were to perform a miracle, would be involved in “breaking,” going contrary to, abrogating, suspending, a natural law. But if God were to perform a miracle, it wouldn’t at all involve contravening a natural law. That is because, obviously, any occasion on which God performs a miracle is an occasion when the universe is not causally closed; and the laws say nothing about what happens when the universe is not causally closed.
What we’ve seen so far is that classical science doesn’t entail either determinism or that the universe is in fact causally closed. It is therefore entirely consistent with special divine action in the world, including miracles. Hands-off theologians can’t properly point to science—not even to eighteenth- and nineteenth-century classical science—as a reason for their opposition to divine intervention. What actually guides their thought is not classical science as such, but classical science plus a gratuitous metaphysical or theological addition—one that has no scientific credentials and goes contrary to classical Christianity.
B. The Laplacean Picture
The Newtonian picture isn’t sufficient for hands-off theology; so what is it that guides the thought of these hands-off theologians? The Laplacean picture. Here the classic statement, naturally enough, is by Pierre Laplace:
We ought then to regard the present state of the universe as the effect of its previous state and as the cause of the one which is to follow. Given for one instant a mind which could comprehend all the forces by which nature is animated and the respective situation of the beings that compose it—a mind sufficiently vast to subject these data to analysis—it would embrace in the same formula the movements of the greatest bodies of the universe and those of the lightest atom; for it, nothing would be uncertain and the future, as the past, would be present to its eyes.
What, exactly, must be added to the Newtonian picture to get the Laplacean picture? Determinism plus the causal closure of the physical universe. Although this addition is not at all implied by the physics (as I said, it's a philosophical or theological assumption), it was and is widely accepted, and indeed so widely accepted that it is often completely overlooked in contexts where it is crucial. And it is this Laplacean picture that guides the thought of the hands-off theologians. It is also the Laplacean picture—the laws of classical science plus the causal closure of the physical universe—that leaves no room for divine action in the world. Given the consequents of the laws and the state of the universe at any one time (and given that the laws of nature are complete and deterministic), the state of the universe at any other time is a necessary consequence. And this would leave no room for special divine action.
Laplace's picture is accurate only if the universe is closed: only if God doesn’t act specially in the world. We could think of the Laplacean picture as the Newtonian picture plus closure. As we have seen, however, classical science doesn’t assert or include Laplacean determinism. The laws don’t tell us how things always go; they tell us how they go when the relevant system is causally closed, subject to no outside causal influence. In classical science, therefore, there is no objection to special divine action. So far, therefore, we haven’t found a religion/science conflict; what we have is only a conflict between religion—Christian belief, for example—and a particular metaphysics according to which the universe is causally closed.
Of course we have been thinking about classical science. What happens if we turn to contemporary science, in particular quantum mechanics? Will we find conflict there? That's the subject for tomorrow’s post.