Reductionism and Quantum Mechanics

David: Some people we're talking to say there's only one kind of knowledge which counts as knowledge ‒ which gets you to the truth ‒ and that's scientific or mathematical knowledge, and everything else ‒ art, poetry ‒ it's just story-telling, it's fantasy, it's entertainment. This is what one person said. Do you hold with that?

RP: Well it's difficult to say what I think because it's an unresolved issue. I think there are things which have to do with our feelings and so on which are very real and which certainly have no room in the physics that we know today. But I'm regarding the physics that we know today as a shadow. That’s maybe not quite the right term. I'm not sure of what's really going on, and we certainly don't almost know what's going on.

Scientific knowledge has the advantage that you can test things, and you can see when things are wrong and when they're right. To an extent you have to be jolly careful with that, too. But they, to a good extent, can tell you when things are right and when they're wrong. Now, that's not true of many things where we have to form our judgements. We have to form aesthetic judgements, often, about things, and are these things reducible to scientific things?

This is a question of reductionism, I suppose, and the view is that you… I suppose reductionism means more than one thing. It means, partly, if you have a thing and you want to know how it works, you say, well, if you know all the parts work, then that will tell you how it works. So you work out how all the parts work. And then, as science has gone, you say, well, you've got molecules, and then we've got atoms, and then we've got particles, and you've got protons and neutrons, and then we've got quarks, and then we've got things which might constitute them, and then you're going smaller and smaller and smaller and smaller.

However, the view of reductionism there is if you know how the little things work, you know how the big things work. But I don't think that's reliable, because particularly it has to do with where quantum mechanics goes wrong. That's big things: things which on the scale of normal understanding of quantum mechanics would be huge.

David: So you think that complete reductionism just can't be right?

RP: It's misleading, I suppose, partly because quantum mechanics itself is not a reductionist theory in a sense. There are these quantum entanglements. You can have experiments which tell you things that vast distances apart are not independent of each other: those things are entangled. This is a basic part of quantum mechanics pointed out by Schrödinger, and these things are now experiments showing this has happened. You can have many, many hundreds of kilometres apart...

David: And does that tell you that reductionism can't be the whole story?

RP: One view is that it is all determined by the little things. So, you know, that's a good old fashioned Laplacian universe thing. It's all determined by the little things, and therefore deterministically determined by the little things. But, yet, there are questions you ask about the big things which somehow are new kinds of questions which you don't see if you just study the little things. Now, I'm saying something more than that: there are things which start to come in on a big scale which are different from what the laws of the little things are. I'm not saying we won't have a theory of that, maybe, I don't know when ‒ it might be soon; it might not be very soon.

David: Does the realm of ideas…? Is that a realm that's not completely governed by the rules of the little things? Do ideas cause things to happen? Are they real? Do they have power in addition to the bumping of molecules?

RP: Well, of course, they certainly…ideas certainly have power, but whether those ideas… You see some people say, well, they're just the little things bumping each other, and they bump each other in a particular way which happens to take off. That would be a kind of view.

David: Do you believe that?

RP: I think that's not the way I would look at things completely. You see it's all to do with this consciousness issue, and I think something else comes in which is outside the science that we presently know. It doesn't mean it's outside science. So you see, when you're asking me is it all science, well, science is limited at the moment, because it only deals with certain areas which don't include that.

David: Yes, but you could say it's going to be natural rather than supernatural. You don't have to say that there's something supernatural. You could say it's going to be explicable by a kind of science which maybe we don't have yet?

RP: I guess I would say that, yes. But then it's hard to know because if we don't have it yet, you don't know what it's like.

David: Alright, thank you.