This is the conclusion of Dr. Alvin Plantinga’s “Divine Action in the World” series, taken from a talk he delivered for Biola University’s Center for Christian Thought. In parts 2 and 3, Plantinga examined the possibility of divine action within the context of classical Newtonian science. Here in part 4, he turns his attention to quantum mechanics and the contemporary picture of nature. He contends that because the laws of quantum mechanics are probabilistic rather than deterministic, they are compatible with the possibility of God’s involvement in the world, including miracles.
In this four-part series, we provide the video of Professor Plantiga’s lecture as well as a written version of his presentation.
Ok, now I want to talk briefly about the new picture—that, I said, was the old picture—now, the new picture: classical science has now been superseded. The Laplacian and Newtonian world pictures have both been superseded, in particular, by quantum mechanics.
The main thing to see here—there is a lot to be said about quantum mechanics and most of it I don’t know since I am not a quantum mechanic, but fortunately we do not need to know a whole lot about it to see the important point here—the important point is this: the laws of quantum mechanics are probabilistic rather than deterministic.
So according to Newtonian mechanics, if you are given a complete description of some system and there isn’t any outside causal influence on the system, then if you ask what is that system going to be like in five minutes, there will be a particular answer. It will be a completely definite answer. Maybe you are not able to get that answer yourself; in fact, there are a lot of problems with actually working this out in detail (maybe you are not capable of doing that), but the laws entail a particular and completely definite answer to all the physical questions about that system. But that isn’t how it goes with quantum mechanics.
In quantum mechanics, if you are given a system of particles, then the quantum mechanical laws don’t say which configuration they will be in, but instead they assign probabilities to the possible outcomes. So there will be a whole continuum of possible outcomes, and the quantum mechanical laws will assign probabilities to these. Some of the outcomes, if you think of it like a distribution like that, at these edges these outcomes will be extremely unlikely; will be assigned extremely low probabilities—those in the middle, a much higher probability and so on, but it won’t tell you just which one will happen, just which one, in fact, will ensue. It only assigns these probabilities.
If that is the way things stand, then even if you leave out the bit about closed systems, miracles, walking on water, rising from the dead, they are clearly not incompatible with these laws, because these laws are just probabilistic. They say like probably things will be this, this, or this. This way of being has a probability of .13, for this one over here, a probability of .007. Miracles of walking on water [and] rising from the dead, these things are not incompatible with these laws. No doubt, with respect to these laws, they are very improbable, but of course, we already knew that.
So the point here is just this: with respect to the new picture, you don’t even have to add the thing about the systems being closed. Even if the system is a closed system, the laws still won’t entail a particular determinant outcome. Hence, these laws are not incompatible with such miracles as walking on water or somebody rising from the dead. In that way, the new picture is quite different than the old picture. It is quite an important difference—a very substantial and important difference.
Now the next thing I want to note though that very many philosophers, theologians, and scientists who are wholly aware of this quantum mechanical revolution still apparently find a problem with miracles and with special divine interaction, generally. There is the divine action project so called by Wesley Wildman in a paper he wrote. It has been a fifteen-year series of conferences and publications that began in 1988. So far these conferences have resulted in five or six books of essays involving some fifty or more authors from various fields of science together with philosophers and theologians including many of the most prominent writers in the field, for example, John Polkinghorne and Arthur Peacock, Nancy Murphy, Philip Clayton, and many others. This whole divine action project is a very serious and impressive attempt to come to grips with the topic of divine action in the world.
Now the interesting thing here is that nearly all of these authors believe that a satisfactory account of God’s action in the world would have to be non-interventionistic. [It] would have a satisfactory account of divine action in the world. [It] would have to be such that it doesn’t involve God’s intervening in the world, really, doesn’t involve God’s acting specially in the world. So says Wesley Wildman, he says, “The project tried to be sensitive to issues of theological consistency.”
For example, the idea of God sustaining nature and its law-like regularities with one hand, while miraculously intervening, abrogating or ignoring these regularities with the other hand, struck most members as dangerously close to outright contradiction. Most participants certainly felt that God would not create an orderly world in which it was impossible for the Creator to act without violating the created structures of order.
Now, when you think about that, there has got to be something wrong with that—the created structures of order (as we now understand them) are understood from the quantum mechanical point of view, and you don’t violate them. God wouldn’t be violating these structures, these laws by causing somebody to rise from the dead (or as far as that goes, by creating a full-grown horse) because the laws don’t say exactly what is going to happen. They only assign these probabilities. Again, no doubt the probability of a full grown horse suddenly emerging right here is very low, but not incompatible with the laws.
There is one more point I want to make here. I think the people that did this divine action project were still sort of hung up on the same sort of thing that people were hung up on before… the same sort of thing those theologians that I mentioned were hung up on… I want to say two things about that.
First of all, even as I say, you set aside the restriction of the laws to causally closed systems; even so, you still won’t get any contradiction with divine special action. That is one. The other thing I want to say is that you really can’t even say what intervention is! I mean, what is intervention on the quantum mechanical level? What would that actually be? There is a way of saying on the old picture what divine intervention would be, but there isn’t anything, as far as I can see, available on the new picture.
Suppose you ask one of these people, “Ok, you don’t like intervention, so tell me, what would an intervention be? Could you tell me what it is?" I mean, if you can’t tell me what an intervention would be, then it is sort of peculiar to be so much against them—you tend to be against things such that you know what they are, not against things such that one cannot even say what they are.
Well, here is one possibility: you might say God does something (A) that causes a state of affairs that would not have occurred if God had not done (A). So imagine the interlocutor saying, “Well that is what divine intervention would be, whether divine intervention would be,” but that can’t be right because then any act of conservation would be an intervention, and they are not worried about conservation, they are just worried about special divine action. So that could not be a good suggestion.
The second one might be this one: God performs an act (A), which is neither conservation nor creation, but causes a state of affairs that would not have happened if he had not performed that action (A), but isn’t that really just acting specially in the world? I mean we are trying to give an account of acting specially in the world, which does not involve intervention. Well, if this is how we understand intervention, well then intervention and acting specially in the world would be the same thing. From that point of view, what they really are trying to do (if you did accept [option] two) you would be trying to give an idea of, an account of divine action in the world that didn’t involve divine action in the world, and of course, that is going to be really hard!
Well, you might try other ones, too. For example, number three: God performs an act that is very improbable given the previous states of the world, but then you want to ask, “Well, what’s the problem with that?” If that is what intervention is, what should be the problem with it? Why shouldn’t God perform improbable acts? If God wants to perform improbable acts, who is to prevent him? That is ok, no problem with that.
Or, number four: there are various lower level generalizations not entailed by quantum mechanics on which we rely, and that is true. I mean things like bread nourishes, people don’t walk on water or rise from the dead—these are generalizations—we all rely on them and believe them, and you might say God intervenes when he causes an event contrary to one of those generalizations, but again, what would be the problem with that? We would think these lower level regularities and generalizations are like the law of the Medes and Persians so that once God has established each one of them, not even he can act contrary to it. In any event, this sort of objection isn’t scientific, it is philosophical or theological.
So, I say, there is nothing in science, either under the old or the new picture, that conflicts with or even calls into question special divine action—including miracles. My general conclusion is that lots of people have raised this problem; they say miracles are incompatible with science. H. Allen Orr said that as well as the philosophers and theologians I mentioned earlier. It is a very common idea that if you believe in miracles, you are somehow not accepting science; you are going contrary to science. My conclusion is that that’s not true at all, either under the old or the new picture; there isn’t any conflict between thinking God acts specially in the world and enthusiastically endorsing all of contemporary physics or whatever science you like. Thank you.
From a presentation sponsored by Biola University’s Center for Christian Thought, and delivered February 12, 2012 at EV Free Church, Fullerton, CA. Used by permission.