John Polkinghorne - Why is the Quantum so Mysterious?

John, if I'm to believe in a God, I'm compelled to try to figure out how God could do the things he's supposed to do, and God is supposed to interact with the world. Well, how physically, and I use that term deliberately, can God interact with the world? How can a spiritual being interact with physical matter? That's a very important question, and actually I think some scientific developments in the 20th century have been helpful in that respect. A lot of people still have the feeling that science describes a sort of clockwork world of just rigid determinism ticking away, and certainly Newtonian science seemed to look like that, and that's why in the 18th century, I mean, Newton himself didn't think that way about God's relationship with the world, but his successors at best were deists who thought God just set the cosmic clockmaker and set it going and left it to tick away. In the 20th century, the picture of the world as mere mechanism has died. We've discovered, first through quantum theory and then later on through chaos theory, that there are intrinsic unpredictabilities present in physical process. Describe how each of those would work. Well, it simply says that we cannot... Quantum theory, for example, says that you cannot know whether a particular radioactive nucleus is going to decay in the next hour or not. You can give a probability, but you can't say for certain that it's going to happen. In other words, there is an intrinsic unpredictability. It isn't a question of if we calculated a bit better or we measured a bit more exactly, we could eliminate that. Even more surprisingly, chaos theory, which came along in the middle of the 20th century, discovered that even the Newtonian world of everyday physics was much more subtle and less mechanical than we had thought. There are these exquisitely sensitive systems, the slightest disturbance from the environment totally changes their future behavior. And again, you can't get around that. It's not something you can get rid of. The classic butterfly wake in China can change the weather in Brazil. That's right. It grows and grows and grows and grows until you get these storms over the Amazon. That's right. A very, very surprising result. So the world is certainly not merely mechanical. It is something more subtle than that. The question is, is it also more supple than that? And here we have a problem because unpredictability is what the philosophers call epistemological. It means we can't know what's going to happen in the future. And it's a fundamental philosophical problem how what we know relates to what is the case. And there are extreme positions taken on both sides. Immanuel Kant thought that we could only know the appearance of things and never know things in themselves. But most scientists take the opposite view. They're realists. We believe that what we know about the world is telling us what the world is like. In fact, we would hardly bother to do science if we weren't thinking of that. If you take that realist point of view, you will incline, I think, to interpret unpredictabilities as not just unfortunate patches of ignorance, but as signs of an actual openness in the future. Not meaning that the future is a random lottery, but that there will be scope for other causal principles to act in bringing about the future. But how could a god interact with that? Well, I'm getting there. I'm getting there. But I have to deal with how we interact with the world, first of all. Go for it. I believe we have a fundamental human experience of agency. I decide to raise my right arm. Of course, there's the bits and pieces that count, currents flow in the nerves, muscles contract. But I, as a whole person, decide to raise my arm. And that would be an example of a causal agent, a top-down influence, my mental decision to raise my arm upon the physical behavior of my body. I believe that we interact in the world in that sort of way. Now, if we interact in the world in that sort of top-down fashion, it seems to me entirely credible that the world's creator also can interact with the world and bring about events in the future. So I have a picture in which God interacts with unfolding process, allowing the laws of nature to control the range of possibilities, allowing creatures to explore in a happenstance sort of way these possibilities, but also reserving some providential room for maneuver on the part of the creator and bringing about the future. Now, that's a complicated picture. We can't disentangle it. If things are unpredictable, you can't pull apart and say nature did this, human will did that, God did the third thing. But nevertheless, all these influences are at work in the world. That's a perfectly coherent and believable picture, and it's the one I hold. Some philosophers would say it's incoherent to have an immaterial God interacting with a material world. Well, there we can move on. Again, I think modern science is a little bit helpful. We're just beginning in science to be able to study complex systems, moderately complex systems in their totalities. Usually in the past, we haven't been able to do that. We just sort of smooth things out, thermodynamics, gas pressure, gas volume, that's all. But now we're able to study the detailed behavior of moderately complex systems, nothing like as complex as a single living cell, but both in physical models and also in computerized models. When we study these systems, we find very astonishing things happen, that they display powers of self-organization, of developing complex patterns of future behavior that we could never have foreseen in terms of the individual behavior of the elements making them up. And that suggests that when we really understand what's going on, this subject is the natural history stage. People study these models, gee, it's happened again, but nobody has a general, there must be a general theory, but nobody knows what it is. I believe that when that general theory comes along, we shall find that instead of simply talking about energy, which has been the traditional discourse of science, we will need also the category of information. And by information, I mean something like the specification of complex dynamical patterns of behavior. That's my guess, and I guess by the end of the 21st century that energy and information will be alongside each other. Now that's a move in the direction of looking at something that's a little bit more mental, a little bit more spiritual, a little bit more holistic in its character. It's not the whole way, but it's a move in that direction. And I suspect that that's the case, that God interacts with the world in a purely, if you like, spiritual way by the input of information, the structuring of the patterns of future behavior. Well, that's another critique that scientists give to the impossibility of God interacting, because they say matter and energy, conservation of matter and energy, it's a closed system, and so if you have God intervening, it changes the matter and energy and therefore is physically impossible. So we have a philosophical argument against an immaterial being interacting with the physical world, and then the scientific argument saying it's impossible because you can't change the matter and energy conservation. It's perfectly clear to me that the science has not established the causal closure of the world on its own terms. There are a lot we have, first of all, you have to make decisions going beyond science to speak about any form of causality. I mean, quantum mechanics is unquestionably probabilistic and unpredictable. Is that due to ignorance, or is it due to an intrinsic indeterminacy? You can interpret quantum mechanics either way and get exactly the same experimental results. So you can't tell scientifically between those two options. And that means that decisions of causality are fundamentally metaphysical in their character. They go beyond simply physics as it is itself. And our knowledge of the world is also patchy. We don't properly understand how the quantum world, subatomic quantum world, and the everyday world of classical physics fit together. There are lots of unresolved difficulties at their frontier. Again, I don't rejoice in that, but that's just a fact. So it is clear to me that science has not and could not establish the causal closure of the world on its own terms. That is, you could make a metaphysical guess that that was so, but I can make a metaphysical guess that that is not so. And I'm free to do that. I'm encouraged to do that because I really do believe that human beings have free will and powers of agency. And I also actually believe that God has providential powers of agency in the world, though that may be a view that is less widely shared. So what is God doing? Is he getting involved in the quantum mechanics of untold 10 to the 80th molecules and parts of quarks and gluons and electrons spin? I mean, it's awfully busy. Well, I mean, if God is infinite, God can be awfully busy, but I think it would be naive and rather foolish, really, to think that God does it all by just scrabbling around the subatomic roots of the world. I mean, I think God acts holistically with creation. But again, you see, because we don't understand how the quantum world and the classical world fit together, the whole spectrum of causal influences in the world is unresolved by us. All of freedom doesn't lie at the subatomic level. All of it doesn't lie at the everyday level. And presumably, some of it lies at even higher holistic levels than that. So we just don't know how to envisage that. All I am claiming is it's a no-go theorem, as people say in science. I'm saying that science cannot preclude the possibility of agency, either human or divine. So God can be working at a... All level. So he can work at the quantum level, the chaos level, maybe some holistic, higher levels. It's like a higher-level software programmer. You don't have to write in machine language, but you write in higher language? Well, but in, again, an integrated way. It isn't God says, today, I'll act at the chaotic level, and tomorrow, I'll do the quantum theory thing. I mean, it's a package deal. I see. And we just don't know how to articulate that package deal. Well, I mean, I love the fact that we're exploring it. Of course. I mean, it gives you a richer feeling of what it means. And it lets you test whether the whole concept is even coherent. Well, the word rich is important. It's very important that we have a rich, an adequately rich conception of the structure of reality, that we don't have this sort of arid, reductionist picture that sees human beings, for example, as simply replicating information processing systems. I mean, that's partly true of us, obviously, but it's not the whole truth about us. And we have to be, the worst error in metaphysics is to, a percussive error, of chopping off the bits of experience that you don't like, to fit it into the bed you already shared.