Alvin Plantinga on Divine Action and Science

In my two previous posts, I reported on a lecture series given at Taylor University by world-renowned philosopher Dr. Alvin C. Plantinga. In this post, I want to discuss his final lecture, which was, by far, the most interesting of the three.

As was the case with his other two lectures, Dr. Plantinga began with a couple of funny stories. He then jumped into the topic at hand, which is how science should deal with divine action in the world. Not surprisingly, there are many who think that any consideration of God taking action in this world is an assault on science. For example, he quoted Dr. H. Allen Orr, a professor of Biology at my alma mater (The University of Rochester), as saying:

It’s not that some sects of one religion invoke miracles, but that many sects of many religions do…I agree of course that no sensible scientist can tolerate such exceptionalism with respect to the laws of nature.

Surprisingly, enough, however, there are many theologians who have the same view. Dr. Plantinga noted that Rudolf Karl Bultmann (a Lutheran theologian), John Macquarrie (an Anglican theologian), and Langdon Brown Gilkey (an American Protestant theologian) all agree that modern science forbids God to do any miraculous works. As Dr. Plantinga noted, these theologians believe that since God put the natural laws in place, even He cannot break them.

To counter such ideas, Dr. Plantinga first noted that many of the scientists who developed our understanding of the natural laws had no problem with the idea that God intervenes in nature from time to time. Newton, for example, thought that God had to constantly intervene in order to correct irregularities that would crop up every now and again. This didn’t seem to affect Newton’s ability to produce enormously good science, which indicates that the notion of God acting in the natural world is not an impediment to science.

There are also many modern scientists who have no problem doing science in a world in which they think God takes action from time to time. Dr. Plantinga didn’t mention this, but Dr. Henry Schaefer III, was the 6th most cited chemist in the world from 1981 to 1997! He believes that God acts supernaturally in the world from time to time, and it doesn’t seem to have negatively affected the way he does science.

Next, Dr. Plantinga stressed that there are two ways scientists have looked at the natural laws: the “old” way and the “new” way. The old way was dominated by Newtonian thinking, which was essentially deterministic. Newton thought that if you knew everything about the starting conditions of a system, and if you knew all the natural laws at work, you could predict exactly what that system would do as time went on.

This approach seemed to be mostly true until the late 1800s and early 1900s, when some odd experimental results kept cropping up. Those odd experimental results led to the development of quantum mechanics, which says you cannot determine exactly what a system will do, no matter how much you know about the system. Instead, you can only talk about probabilities. You can say that there is an X percent chance that the system will do this, and a Y percent chance that it will do something else, but that’s the best you can do.

Dr. Plantinga then went on to show that regardless of which view you take (the “old” Newtonian view or the “new” quantum view), there is no problem with the concept of God supernaturally acting in the world. If the Newtonian view is correct, all you have to realize is that the laws of nature assume no outside interference. For example, he quoted several physics textbooks as stating that laws like the conservation of momentum, the conservation of energy, etc., require a closed system. Momentum is not conserved if an outside force is acting on the collision, and energy is not conserved in a system if energy can be imported into the system or exported out of the system.

Thus, he proposed that the natural laws really should really start out with the statement, “When the universe is causally closed…” That way, it is clear that if God intervenes, there is no break in the natural laws, because during that time, the natural laws don’t apply. Since Christianity clearly shows that God’s divine intervention in the world is a fairly rare act, then the scientist just has to realize that the natural laws he or she discovers are good general descriptions of how the world works, but every once in a while, they simply will not apply.

While I listened to Dr. Plantinga’s argument, it struck me that such thinking is very scientific. Indeed, scientists regularly ignore outliers in their data. If a scientist collects 100 data points, and 99 of them show a distinct pattern but 1 is far off that pattern, it is generally considered an outlier. Often, a scientist will ignore the outlier in trying to understand what the bulk of the data mean. Using this reasoning, then, God intervening in nature is the outlier. It doesn’t happen very often, and when it happens, it should be very clear. As a result, it is easily ignored when coming to scientific conclusions.

In the Quantum view, God’s intervention in the natural world is even easier to understand, according to Plantinga. Indeed, since the best that we can do scientifically is to give probabilities as to what a system will do, God can act by “forcing” a particular event to come true, regardless of how improbable. For example, I have often noted in my lectures that quantum mechanics says that it is possible for me to run into a wall and pass through it without any harm coming to me or the wall. It sounds odd for this to be true, but I can actually demonstrate it in the lab on an atomic level.

On the much larger level of me and the wall, it becomes ridiculously improbable, but not impossible. If God saw me careening into a brick wall, then, he could just “fix” the situation and allow a ridiculously improbable event to occur so that I passed right through the wall. It would look like a miracle, but it wouldn’t even be a violation of any physical law. It would just be a case of God making sure the one possible event that fit His desires is the one that actually occurred.

The other thing Dr. Plantinga noted is the quantum concept of superposition. In this view, which is supported by experiment, a particle can be in several states at once. Observation then causes a resolution, which makes all but one of those states go away. Whatever is left is the state in which the particle is observed. For example, if you observe an electron one way, it seems to behave as a particle. If you observe it another way, it seems to behave as a wave. The Copenhagen interpretation of quantum mechanics (which is the leading one) states that before the measurement, the electron is both a particle and a wave. Then, observation forces it to become one or the other. Dr. Plantinga noted that since God is an observer, it could be possible that He works in the universe simply by observing in a particular way, which causes the desired state to emerge.

I really didn’t like Plantinga’s view of how God might work through quantum mechanics. It was quite interesting, but to me it seemed to limit God quite a bit. In the question/answer session, I noted that there are many states for which quantum mechanics says the probability is exactly zero. For example, if I am watching a Californium-252 nucleus fission, there are all sorts of different ways it could end up splitting, and I can state the probability for each of those ways. However, there are also many outcomes that are simply impossible. For example, the probability that the fission products of Californium-252 will have a total of 253 nucleons is exactly zero. Thus, this would limit how God could work. Dr. Plantinga agreed with that, noting that if God wanted a zero probability event to occur, we would be back to the original idea, that such a probability assumes a “causally closed” system.

In the end, I think Dr. Plantinga’s first idea is the best one. Natural laws assume that the universe is causally closed. If there are times where it is not, the natural laws don’t necessarily apply, at least not to certain specific systems. Such events, however, are rare, and can simply be seen as outliers in the overall trend of how the universe works.

I think Dr. Plantinga summed it up best during the question/answer session:

If you are a medical researcher and believe that God can miraculously cure cancer, that won’t stop you from finding a cure for cancer that works according to the natural laws.

15 thoughts on “Alvin Plantinga on Divine Action and Science”

  1. Exactly on the mark! I do not understand how theologians can argue against miracles. It does not need a fancy piece of kit to determine that “natural law” forbids feeding 5000 people with 5 loaves and 2 fish and collecting 12 baskets of leftovers. The Bible makes it clear that God is superior to natural law and such things do occur.

    I tend to think of the proper Scientific Christian’s response in terms of a programmer putting Case Else statements in their code; having the humility to acknowledge that something else might intervene no matter how tight you think you have your logic laid out.

    Incidentally this is also why I still maintain that it is not a lie for God to perform a miracle that leaves a dataset that extrapolates back to something which never occurred. Instead our interpretation of that data is flawed in its assumption that God couldn’t have acted to produce it.

    1. An interesting point, Josiah. However, I would point out that in the case of 5,000 people eating with 5 loaves and 2 fish, it is clear that God is at work there. As I continue to maintain, I would think God would make it clear He was at work when it came to such data sets…

  2. Perhaps. Yet if you only consider evidence based on fundamentally naturalistic science you can’t see material evidence as indicative of God’s work. Consider that God has already made it explicitly clear where he worked in Scripture, you cannot accuse him of any wrongdoing if the human then commits what amounts to a No True Scotsman by ignoring what he says in that book.

    1. I guess I would disagree on both major points. First, I do think you can use naturalistic evidence to see God’s work. For example, I think the incredible design you see in nature is naturalistic evidence for God’s creative work. Second, I don’t think that Scripture has made it “explicitly clear” where He worked. If it were “explicitly clear,” there would not have been so many major disagreements among Christians through the centuries regarding things like the age of the earth, the details of creation, and other such things.

  3. In the first case we don’t disagree, but differ on what is meant by “naturalistic”. As you’ve mentioned earlier ( is a long standing debate among scientists as to whether “Science” must find a natural interpretation to explain everything or whether it is acceptable to acknowledge supernatural. If you examine the natural world with an open mind, the heavens declare the Glory of God. But if you examine it from a purely naturalistic perspective and insist on devising a theory of the stellar life cycle you will not see God in that at the end. Of course if you insert Else If God… statements into your reasoning to acknowledge the “casually closed” assumption you’ve already made then you don’t have to ignore God. It remains however very difficult to apply the scientific method to el elyon so that else statement is a bit too misty to make further predictions on.

    If you insist that God makes things “explicitly clear” and so obvious when he works that no-one can deny exactly what happened then you clearly find the data goes against you. There are a lot of highly intelligent people who disagree on the very point of God’s existence, let alone on what his precise role is! You’ll also find it’s impossible to have God’s scientific record match up and be interpreted perfectly, because science isn’t explicitly clear.
    Even so in general it is the Christian who takes the Bible literally as it’s written (and sees it as explicitly clear) who would insist that ‘Science is unable to plumb the depths of God’s actions and the disagreements between science and theology are the inevitable result of the miraculous’ (my words). Theologically I don’t have a problem with that final statement and certainly don’t see it as deceit on God’s part, though rationally I do think they’d be better off learning about the fields they want to argue in rather than making up disagreements that may not exist!

    A small disclaimer: I do loathe the argument that “God put J random contrary evidence here to test our faith”. That does imply unapologetic deceit on the part of God.

    1. I certainly agree with your ending statement, Josiah. I still don’t think you understand my position, though. I do not insist that God makes things “perfectly clear” when He works. Indeed, He doesn’t make things “perfectly clear” in Scripture, so why should He in the natural world? What I do contend is that He doesn’t make up false stories. Thus, when data tell a story (tree rings, light coming from distant galaxies, etc.), He would not create it to tell stories that are not true. You say it is the scientists’ assumptions that are reading things into the data that aren’t there. I say that God has already shown us such data tell a story, and as such to continue the story without any hint that the story is no longer true is, in fact, a lie.

      I would certainly agree with the statement that “Science is unable to plumb the depths of God’s actions and the disagreements between science and theology are the inevitable result of the miraculous.” However, that doesn’t apply to what I contend, since the issue is not whether current scientific thought and theology disagree. The issue is whether or not God gives us a natural way to infer history and then continues that into a false history without any hint that the history which has been rightly determined moves right into a history that is manifestly false.

  4. I think that the notion that a miracle “violates” natural law is a misguided one… it prescribes what a miracle must be without leaving room for a very natural-seeming logical possibility; namely that the language game that we play involvi…ng “laws of nature” shouldn’t involve the presumption that there are fixed inviolate abstract objects called “laws” that dictate how the universe “should” be, but rather that they are descriptive of how the universe IS. This means that a “miracle” involves something about the way things are outside of the scope of our descriptions.

    One such “miracle” is our ability to have any knowledge of the way things are at all…

    1. Thanks for your comment, rigelrover. I certainly agree that a miracle is not a violation of a natural law. Instead, one must understand what a natural law really is. Plantinga says it is something that assume a causally-closed universe. You say it is simply a description. Either way, miracles certainly aren’t a violation.

      I am not sure that our ability to have knowledge of the way things are is a miracle. I do think it is a gift from God, but that gift could just be a consequence of how the universe works.

  5. Ok… miracle vs gift from God I think you’ve got me there! But we might say that there is no proper natural description of our knowledge, so it is left to us to either deny it as such or to accept that it was given by God and that’s all. In this sense I have no problem calling it a miracle.

  6. Actually, I think that the “description/prescription” distinction is logically equivalent to the “closed/open” distinction…

    Does that sound plausible?

    1. I would agree that the “description/prescription” distinction is logically equivalent to the “closed/open” distinction.

      I would not agree that the only option is to deny our knowledge or accept that it was given by God. I think the naturalists have a good argument for how our ability to have knowledge evolved. Those who have an accurate knowledge of their surroundings are more likely to survive, so our ability to tease out such knowledge simply evolved, just like all our other abilities. I disagree with them, but I don’t see their argument as invalid.

  7. I am a little shy commenting next to such people given my limited understanding of science. I just wanted to ask why scientists and theologians sometimes feel that God does not do a miracle. I mean, isn’t someone recovering from cancer that they shouldn’t recover from miraculous? Isn’t someone surviving injuries they shouldn’t survive, miraculous?

    God is a God or Order, and abides by His rules for the most part, as that is how He has designed the universe for us to be. But if He has a higher purpose behind interference, is it not both within His power, and His legitimate purview, to intervene?

    1. Timothy, you shouldn’t feel shy in the least. Your comment is excellent. The naturalist would say that someone surviving terminal cancer or mortal injuries is simply the result of us not knowing everything there is to know about the human body. Because of our ignorance, what we think is a terminal disease or a mortal injury is not necessarily terminal or mortal. Some theologians would say that much like a legislature must abide by the laws it enacts, God must abide by the laws He enacted. Of course, I disagree. As you so correctly put it, if His purpose is legitimate, He certainly has the power and right to intervene and break His own laws.

  8. But he is not breaking them (especially if they are “His own”), but merely extending something about reality (about the possibilities inherent in His nature) into a place where us humans have deemed such a thing impossible. Reality is an open system (from God’s point of view), and a closed one from ours…

    1. Well, rigelrover, I guess it depends on how you look at it. If a legislator did something against a law he enacted, he would be breaking it. Of course, according to Plantinga (and I agree), the laws of nature assume a causally closed system. If that is correct, then you are right. The universe is causally open for God, so His intervention is not a violation of the natural laws.

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