Can everything about life be reduced to the movement of atoms and particles?
David: Can you tell me what reductionism is?
DN: I think reductionism is the idea that from the molecular level you could reconstruct everything: that, in principle, at the molecular level, everything is there that is needed in order to know how your body works, and that cannot be true.
David: But reductionism is very powerful though, isn’t it? You’re not saying, ‘Reductionism, we shouldn’t use it’?
DN: Of course it’s been hugely successful. It was fantastic, and actually it’s given us huge insights, so I’m not an anti-reductionist. I just think that you’ve got to recognise that there is an integrative process occurring in living organisms, and those functional properties, the meaningfulness, if you like, in that function, because, after all, the rhythm of the heart has meaning; that emerges, and you can’t escape from that.
David: Then why are people so wedded to it? Reductionism?
Ard: That’s a good question.
David: I mean, you both mix with scientists all the time. Why are they so…?
Ard: Because it is a powerful thing. The fact is you can…
DN: The power is great, yes.
Ard: The power is great. You can take something, break it in to parts, and you can really understand. For example, you figure out the molecular structure of DNA and suddenly you understand how certain types of genetic information are encoded in a digital form.
Ard: I think that’s an experience that when you have it, it’s very natural to think, well, that is so powerful, it must the way of explaining everything. This powerful method is a method we’re going to use, and we’re going to apply it universally.
David: And only that method. That’s…
Ard: But I think Denis’s point is to say, ‘Well, if you just use only that method, then you’re missing something.’
DN: That’s right, exactly.
Ard: It’s not the same as saying that method is wrong, just that the method is not the only method.
DN: Exactly so, and where it goes wrong can be illustrated, because what Crick did after that discovery was to immediately go out to one of the taverns in Cambridge, where he would drink with his friends, and he announced in the tavern, ‘I have found the secret of life!’
Wow! He had not found the secret of life, because if I take the DNA out of a cell and I put it in a Petri dish with as many nutrients as you like, I can keep it for 10,000 years: it’ll do absolutely nothing. It can’t be the secret of life.
Ard: Right, yes, so this gets to the whole argument about, are genes the recipe for life?
DN: Yes, it does, and the problem with this is that… Recipe is not bad, I mean, it’s written down as a recipe, just like a music score is written down as a music score, but the recipe is not the dish.
David: And the score isn’t the music.
DN: And the score is not the music. Precisely. And so it’s the mistake of thinking that because it’s written down, it must be the thing itself.
Ard: Exactly. I think that’s a great way of explaining it: it’s confusing the recipe with the dish.
DN: With the dish.
Ard: And they’re thinking, once you understand the recipe, then you’re done.
DN: Exactly so.
And one of my big problems with the reductionists is not so much that their method has not been extremely powerful. It has been superbly powerful. It is the hubris: the certainty that that’s all there is.
Ard: I remember when I first learned basic statistical mechanics and how to calculate ideal gas law from the interaction between the atoms, and then I began to calculate more complicated gas laws and then equations of states. It’s a very powerful and beautiful thing.
GE: Yeah, it’s beautiful.
Ard: And so it’s not so surprising, sometimes, that if you’ve had that experience, you think this is the best way of understanding the world.
GE: Yeah. And in my view, the scientifically legitimate thing is to try and extend that as far as you can, so you can see the widest domain that you can explain by it. The problem comes if you try to say this is the only thing which is happening; it’s the only kind of causation that is possible. That’s where the problem comes.
And so I have this definition of a fundamentalist. My definition of a fundamentalist is someone who takes a partial truth and claims it’s the total truth, and that’s exactly the problem here.
If you say that statistical physics explains a lot of stuff, there’s absolutely no problem. If you claim it explains everything, including life, it’s simply not true. And I think a lot of the problem here is that the people who are wanting to say that all we’ve got is the bottom-up causation... they are just… one should pursue bottom-up causation as far as one can, and it’s very powerful, but it’s not the only thing in existence.
In fact I make quite a strong claim there. If you want to create life, there’s a level, a ceiling that you can reach by bottom-up assembly of molecules and so on, and you can’t get any further for one very simple reason: after a certain time, adaptive selection has to come and you’ve got to start adapting to your environment. Now when that happens, the environment has to feed in signals to this organism which will change either its structure, or its behaviour, or both.
Now, that’s top-down causation from the environment into the structure of the organism at the macro level in your organism and down to the electrons and protons in the organism. If that top-down causation does not come into existence, you can’t get life, and so I make a strong statement that purely bottom-up causation will not bring life into existence.
David: Ah, that’s very interesting. Because you are saying it feeds information in, and you have said that before: information is the new thing.
GE: Yeah, what’s DNA about?
David: Life is information: it’s coding. And information is a real thing, but it’s not physically real is it?
David: Because the information is different from the way that it’s encoded.
Ard: And the information is coming in from the environment.
David: That’s fantastic.
GE: The whole point of DNA, the wonderful discovery of DNA, is that it can, like a Turing machine, it can encode any protein structure you like, any one at all, and the physics doesn’t determine which comes out. So if you’re a tele-physicist, predict for me what the DNA sequence is going to be. You’ll shrug and say, ’I can’t do it’, because this ain’t physics, it’s biology. It’s a different logic, as it were.
David: So is that an emergent level then?
GE: Yes, absolutely. But why people believe in reductionism is the unbelievable success. And you experience it, as you were saying, with the kinetic theory of gases. It works absolutely beautifully. The atomic structure of matter has been a huge success. Then there was the physical structure of chemistry. The wonderful, wonderful discoveries of Linus Pauling and all these people of how chemical structure emerged, the quantum physics. Wonderful success.
Then there was the molecular biology revolution with Crick and Watson and so on, and life is molecules interacting with each other, and there’s this DNA coding and so on. Wonderful.
And then there was the whole thing of neurons and how you could understand the mechanism of the brain in terms of electronic impulses going down axons and dendrites according to laws which are perfectly understandable in terms of the underlying physics.
And so the reason people pursue it is because it’s been so incredibly successful in a most extraordinary kind of way. But, in each of these areas, there’s always been a counter-reductionist thing, like in the case of statistical physics. The arrow of time is still a worm at the bottom of the thing in the case of statistical physics. In the case of chemistry, chemistry is a success in principle but not in practice.
In the case of the genes there’s been the whole epigenetic thing coming back and saying causation is not only bottom up. Epigenetics is the solid statement there’s a mass of top-down causation. And in terms of the mind, you find you cannot understand the mind in bottom-up terms only.
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.
Ard: We’re going to switch topics. That was great. That was really helpful.
Ard: So why don’t you ask about reductionism because that’s the one you’re… So we’re interested in emergence and reductionism.
David: We’ve gone around asking everyone about the two and trying to get them to define both.
GE: And you’ve got 150 different answers.
David: You said it George. So would you like to add one more?
David: And I should stress, we’re not trying to be in any way anti-reductionistic. We’re just saying, what are they? What are its strengths? What are its weaknesses? Is it the answer to everything or not?
GE: Reductionism is the question: can you, in principle, completely explain what happens at the higher levels in terms of what’s happening at the lower levels?
David: And what do you think?
GE: Well my answer is absolutely not.
GE: I think a very good place to start is digital computers because digital computers are something which we can actually understand fully. Now a digital computer, it’s made up of all of these gates, transistors joined together by wires and then put together with a keyboard and a display and so on, and you can look at it at the different levels. At the bottom-most level it’s electrons flowing through the gates in a particular way, and that’s what controls what happens at the screens.
But given that hardware – there’s the hardware sitting there – it doesn’t do a thing until you load it up with a program, and what the identical hardware does is completely different depending on the software you load. So if you put in a word processing program, a music program, a paint program or something, you have completely different outcomes from the identical hardware. So the hardware, per se, does not determine what happens. What determines it is the program you load in. So now the question is, what is the ontological nature of a digital computer program?
David: When you say ontological…?
GE: What kind of existence does it represent? And now the hard-line reductionist will say that it’s nothing but electron states in these gates. Now that is completely wrong, and a useful side-step here is to think about what is the ontological nature of a book.
Now in the old days we all thought of a book as paper with printing on it and covers, and that’s a book. Now the question is, is it the same book if it’s got a different size print? Is it now still the same book? Is it the same book if you print it in italics or not? And I think we all agree it’s the same book. It’s different instantiations of the same book.
Nowadays we know that the book can be given to you in electronic form. Is the electronic form still the same book? And my answer is yes. The book is the abstract quantity which can be instantiated in those different ways. Now a computer program is the same: it’s an abstract entity; it’s not a physical thing. And so some people say, ‘But it’s here: it’s the CD disc.’ But it’s not the CD disc. Is it the excited states in the gates? That’s an instantiation of the computer program. And actually a computer has got layers of structure: there’s the machine language, the assembly language, there’s the operating system language, there’s the high-level language, and what is the key thing here is that there’s a logic in the computer program.
That abstract logic then gets written into a high-level code. What happens in the computer is absolute magic. The high-level code gets typed in and then interpreters or compliers write it down in to the lower-level languages.
Exactly the same logic is present at every level, but it’s represented in a different way with different rules, and at the bottom level it gets turned into instructions at the gate, and it gets turned into electronic states in the gates. Now, what is the computer program? It’s the equivalent class of all of these representations: it’s an abstract thing. Does it have causal power? Yes, it causes things to happen.
And very, very similar to this is the rules of chess and the rules of football. Those are abstract agreements and they can change with time. Now, the rules of chess determine what happens on the chess board, and I like to imagine this Martian coming and watching chess – after a while he works out these different motions, and then he picks up the rook and he looks underneath it. ‘Is something causing it?’ And then he can’t figure that out, and so he invents a force field which acts on rooks and only enables them to move in different force fields…
David: Looking for a physical explanation?
GE: Looking for a physical explanation. It’s a mental explanation. It’s a set of rules, abstract rules, and again they’re abstract, they’re not physical things. And they can be realised in a computer program or in your mind, or they can be realised in a book and so on. And again this multiple realisation, whenever you’ve got multiple realisation of some concept, it’s telling you that there’s causation from the concept to all of these realisations.
David: So you’re saying an abstract logic has this power?
GE: An abstract logic has physical outcomes in the real world through being what is implemented in a computer. So then, of course, the old philosophers of mind would say, ‘but you’re talking a dualist position.’ My answer is, ‘yes I am.’ A computer is a dualist machine: there’s the hardware and the software.
David: So you’re saying there’s a difference between the mind and its ideas, and the brain?
GE: Yes, I take the completely unpopular position: I’m a dualist. There’s the mind and the brain, and the mind inhabits the brain… or thoughts, thoughts inhabit the brain and thoughts are not physical things. Thoughts are abstract things which get represented in a physical way.
And again we do not understand how this happened, but the brain has a hierarchical structure. Thoughts have a hierarchical structure, and in the computer you can see these different levels. You can understand them, and you have got these interpreters or compilers which do it. I think eventually when we understand the brain enough, we will see exactly the same kind of structure happening in the brain.
The logic is going top-down from the top level down to the bottom and it is the logic which is controlling what happens at the bottom level. Abstract entities are driving the physics at the bottom level. The physics is not controlling what happens.
David: So that is exactly the opposite of when people say the reductionistic picture is always once you’ve understood these things at the bottom, they are what cause things to happen?
David: The cause always runs from the bottom up?
GE: Well it goes both ways, and there’s a large literature on what is called supervenience.
David: What is supervenience?
GE: Supervenience is if I knew everything about the bottom-level state – and let’s take the computer as an example – so I know the wiring and the chip; if I knew at an instant all of the states of the electronic gate, and then I reproduced it over there in another computer in exactly the same way, then it would give you exactly the same high-level stuff there. So at that level the reductionist picture is correct.
But the question is, how did those bottom-level states get to be in the excitation states that they are? And that can only happen top-down from the logic controlling what happens at the bottom level. And something similar like that will be happening in the mind.
David: I was just thinking about why so many scientists are really wedded to reductionism, and is it because they think the only thing that you could add into the universe, that isn’t what the reductionist story has in it, matter, that they think you’re going to import the supernatural? Whereas you’re importing something that is not supernatural. You’re saying there’s a realm of ideas, which isn’t supernatural.
GE: No, it’s not supernatural in that sense. The ideas don’t reach down and act of themselves.
Ard: Like ghosts.
David: No, true, okay.
David: Can we go back to reductionism? You said you felt that there was… we’d come to the end of that particular kind of science. What did you…?
MG: I wouldn’t say that. No, I don’t think you can…
David: What did you…?
Ard: There’s a danger of reductionism, at least?
MG: Reductionism has been physics’ best friend, in the sense that it’s been so useful as a way of making sense of what’s going on, because what it does is if you have something very complicated, you break it into little bits, study the little bits, put things back together again and hope that the total is the sum of its parts.
And the ultimate goal of reductionism, of course, is to reduce everything to the simplest possible components. So this notion goes all the way back to atomism, the old notion of atomism from Greece, where matter is made of little things, and hence you just have to put them back together again like Lego, like little Lego blocks.
Ard: So reductionism is this idea that you can break it into the parts, but the whole is nothing more than the sum of the parts?
MG: Exactly. And that’s true for many systems. But it gets harder when the systems are not so well-behaved and they have many, many interacting parts.
But there is a place for reductionism in science, obviously. The fact that every atom of hydrogen is the same around the universe is a triumph of reductionism. And it’s true, they are the same. There is this fundamental repetition of these basic building blocks.
And that’s why it’s been so tantalising to extend this notion to everything there is. So people have tried to do mechanistic models of pretty much the mind, and the weather, and…
MG: …life, and even economics. And those things just don’t do very well.
Ard: And they don’t do very well because those are things that are emergent in some way or the other?
MG: They don’t do very well because sometimes, depending on the complexity of the system, if you have a system that has many parts, they interact with one another in what we call non-linear ways. So a non-linear interaction is if you kick, a rock it kicks you back in the same way. In a non-linear world with non-linear forces a small stimulus can create a huge effect, and vice versa. So it becomes much harder to predict the behaviour of a system which has many parts doing that at the same time.
The thing about reductionism is that it tries to make the universe into a big machine, like clockwork, and that is a very old idea from the 18th century, 19th century, where, if everything is mechanistic – there is this big engine behind everything – then everything is explainable and everything is predictable. This is the ultimate determinism.
And the consequence of this is that if everything is predictable, so is behaviour, so is what I’m going to say now. And that makes us a prisoner of this machine. And that tells you that you’re really not a free person: that there is no such thing as free will.
And that’s why the Romantics were so pissed off at the scientists, because they were saying, ‘Hey, it’s all a big machine.’
And they would say, ‘Wait! Wait a second. What about love and feelings and confusion and doubt? Where does that all fit into this new science you guys are talking about? That’s not the whole picture. It cannot be the whole picture.’
So that is where reductionism starts to flounder. Because, basically, it’s trying to do much more than it can, which is to predict the future in a way which is 100% accurate, and we know now that that’s not possible.
David: And is that dangerous for science, do you think?
MG: It is dangerous for science, because whenever science says that it can understand everything – including who you are, and who you’re going to be, and how you’re going to grow up – it’s robbing people of themselves. It’s basically killing their persona, in a sense, and saying, ‘You really are just a mountain of atoms, and if I know how to crank this machine, I’m just going to tell you who you are,’ and that just makes you dumb. It makes you into an automaton, and nobody wants to be an automaton.
David: It robs the world of meaning, doesn’t it? It says there’s just the machine. Someone’s turning the little handle on the machine, and it doesn’t mean anything.
Ard: Well, no one’s turning it. The machine’s just…
David: Well, it’s turning itself.
Ard: The machine’s just kind of rattling along. You may think that you’re doing something, but actually it’s the machine that’s rattling along. And so, there is no self…
David: Does it rob it of meaning?
MG: Well, it does because it basically tells you that there’s no point in searching for anything because everything is already written. There is no point in trying to understand who you are, because who you are is really pointless. It’s about electrons interacting in this big complicated way, and nobody likes that, right? I mean, you want to be able to be mysterious. People want mystery before they want reason and certainty. I think people need to not know.
Ard: But just to interject… Some people are saying, ‘Well, that may be the case that you want this, but I’m sorry for you.’
David: Yeah, grow up!
Ard: Grow up, yeah. Grow up and face the cold, hard reality that we are nothing but a bag of chemicals.
MG: Oh, we are definitely nothing but a bag of chemicals, but we have no clue how to predict how that bag of chemicals will behave.
MG: So to say that reductionism fails doesn’t mean that there is more to it than matter. It doesn’t mean that there is some sort of soul or spirit that is controlling stuff. It just means that science cannot do that job, and I think that’s a wonderful thing.
People ask way too much of science. Some scientists, the ones that push reductionism all the way to the end, they are asking science much, more than science should be able to answer, which is to answer everything.
Science was not designed to give us all the answers. In fact, science thrives on ignorance. We need not to know in order to create new knowledge. And so this belief, because it’s nothing more than a belief, that science can probe into the behaviour of everything and come up with final answers about who you are, or even about what nature is, it’s really a misunderstanding of what science is about and how science actually operates.
Ard: But I think the argument sometimes goes like this: ‘Well, we don’t yet have a science of free will, or who you are, but we will one day. Because we didn’t used to have a science of gravity, but now we do. We didn’t used to have a science of quantum mechanics, but now we do. And so, one day we’ll have a reductionist explanation of everything in Marcelo Gleiser based on the atoms in his body.’
MG: And that to me is like a prayer. You know, like praying. You know, to me, what’s really important, right, is that we are creatures that look for meaning in everything that we do. We want to feel justified in our actions, and those scientists, you know, who are saying that there is an ultimate knowledge, that is their search for meaning.
MG: That’s what makes their lives meaningful. You know, if there is anything that says what is the meaning of life? Right? Well, the meaning of life is to live a life full of meaning, and that’s exactly what they are doing in their own way. So, if they believe that you can understand everything, then, that is the ultimate quest of the rational mind, and you dedicate your life to that, that is what gives them meaning, and that is awesome.
MG: You know, good to them! And what I’m saying is that there are other ways in which we can find meaning in your life. To me, the way I look at this right now is… I look at what we learned about the universe, what we have learned about all the planets outside of Earth, what we have learned about how life evolved in this planet – and we know how rare Earth is and how rare we are as a species, an intelligent species, the, sort of, stardust that can actually think – and that brings us back, we humans, to the centre of things. You know, not in a Copernican way, that we are the centre, but in the fact that we, like Carl Sagan said before I did, are how the universe is thinking. And because of that, and I have my little crusade here, we should be guardians of life, and specifically of this planet.
So, to me, this new science, instead of saying, ‘Oh, the universe is enormous. We are nothing. We are just machines. We have no free will’, no, we are actually incredibly important because without us the universe wouldn’t have any meaning, because there would be no one to think about meaning in the universe.
David: Running through our conversation has been this sense, listening to you, that ideas, in your example ideas, that you find beautiful, are very powerful: they can guide what you think and what you do next. Do you think that ideas really do have that power? That they are as much a force in the world as the basic forces you are thinking about?
Because non-scientists tend to think physicists are always going to say that everything that happens is just these particles bumping into each other. And here you’ve been talking about it as if thoughts themselves shove the particles around: it was the thought which led you to the next idea. Do you see what I mean?
FW: Yes, I think I do.
David: It’s saying the radical reductionism that says everything that happens is determined by the bumping of the elementary particles, taking Laplace to the extreme…
FW: There’s a concept that Niels Bohr elaborated that I’ve fallen I love with that I think is very profound: it’s called complementarity. It’s something that’s just a true fact about quantum mechanics but is much more general. It’s the idea that you can have different descriptions of the same thing that are both valid, and both important for answering different kinds of questions, but they are mutually incompatible. It’s closely connected to wave particle duality. There are different ways, mathematically, of processing the wave function. I think that’s a much more general principle. Well I know it’s a much more general principle, and I think that it even applies to things like the problem of free will versus determinism.
There’s one description based on physics that tells you that, for practical purposes, in principle, the brain, for instance, is a pretty nearly deterministic, noisy, but deterministic system. Whereas if we want to deal with our own experience, if we want to interact with other people, if we want to have sensible systems of law, we need to use this concept of free will. And they are both valid descriptions, but they are meant to address different aspects.
David: But you think they are both genuine? Because listening to you, it was on the tip of my tongue to say there’s the rejoinder which says, ‘Yes, but that stuff about free will: that’s just a place-holder until we’ve really worked out the physics, and really, ultimately, there’s no such thing.’
I’ve talked to scientists who have said there is no such thing as free will; there is no such thing as the self; there’s no such thing as consciousness. I’ve had all those things said to me in the last five or six years, and the answer is always the same: ‘I know you think you’re conscious, but actually it’s just the chemicals in the air and they’re buzzing around and that’s why you’re laughing, it’s not because anything is funny.’
FW: This reminds me very much of Dr Johnson after hearing Bishop Berkley’s sermon about the unreality of matter, and famously Boswell said that this seems crazy but it’s impossible to refute. And Johnson kicked a stone and said, ‘I refute it thus.’ So when people say there’s no such thing as consciousness, come on!
David: I’m with you on that, but there is that sense that…
FW: Okay, we can illuminate it. It’s like saying there is no such thing as life because we can understand it on a molecular level. Life! There are useful concepts that are necessary in describing large domains of experience that aren’t going to go away. They may have alternative complementary descriptions.
David: But you think they’re real?
FW: Yes, I think they’re as real as anything can be. They are useful. They describe actual things in the world.
David: And ideas would be one of them? That realm of ideas?
Ard: And I think what you’re saying is that they may be contradictory if you try to have them at the same time?
FW: Yes, if you try to apply them at the same time, they can lead to contradictions.
Ard: But, nevertheless, they are both true if you are asking the right kind of question?
FW: They are both useful and necessary, I think, in addressing different kinds of questions.
Ard: In your book you say, for example, objects and persons are complementary.
FW: This is very much relevant to the discussion of free will. When we are trying to predict what they’re going to do, how we should interact with them, we are thinking of them in one way. If we are thinking about them as what their height is; what their mass is; what they are as physical objects; am I going to run into this object? If I’m diagnosing a disease, I want to analyse the chemistry. That’s a different way of thinking.
Ard: And those two ways are complementary to each other?
FW: They’re complementary. They’re both valid, but there’s a lot of tension if you try to apply them at the same time.
Ard: That’s really interesting. That’s a profound point that they’re both valid ways, so the world of the person is the world of intentionality, and the world of ideas as well. And then there is the world of the human being as a wet computer, a bag of chemicals, and they’re both useful. They may even illuminate one another, but if you try and apply them at the same time, or if you say that one is superior to the other, you’re missing something.
FW: Yes, that’s a good way to put it: you’re missing out. It’s not that you’re wrong in some sense, well I think actually that you are wrong, but at the very least it becomes very awkward to express concepts of intentionality, of emotion, of ideas in physical terms.
David: So are you sympathetic then to people like George Ellis who think emergence is something that’s a useful idea?
FW: The general concept, I think, is very much in line with these ideas about complementarity: that different levels of description can be useful, and if you’re describing the same thing in different ways, it’s also important, if you can do it, to make those consistent and get a rich interconnection between the two. So yes, I have a lot of sympathy for that. But where I don’t go is, I think our description of the world based on what Newton called analysis and synthesis – and I would like to call it that, but many people call it reductionism – the idea that the way you build up the description of the physical world is by understanding very small parts thoroughly and getting a complete description of those and then building out from there. That’s been extremely fruitful, extremely successful, and I don’t see any sign that it’s open to influence from higher levels. So specifically, for instance, at an accelerator, I don’t believe that no matter how hard you think about it, you’re not going to change how the protons collide.
David: It does sound a little bit like you’re trying to have your cake and eat it too. Obviously the accelerator, you chose the example because it works for what you were just saying, but then let’s take the mind again: does that mean the next word I’m going to say is forced upon me by the particular configuration of all of those particles? Or was it that I was having a thought and the logic of the thought dictated what I would say next?
FW: If you are discussing thoughts and how they evolve, then the appropriate language is cognitive language. That’s the way that people have found useful and have developed to express and analyse the development of thoughts. If you want to know about brain events, especially at a microscopic level, then you want to use quite a different description. Those can both be valid descriptions.
David: They have to be, in a sense.
FW: I think they are, but for different questions. If you want to use thought patterns to predict how chemical reactions and atoms are going to behave, I don’t think you can get very far. There are many, many different chemical reaction patterns and things that could correspond to the same thought, and conversely only slightly different chemical patterns could lead to grossly different thoughts. So it’s not a stable, simple mapping. It’s very complicated at best, and practically useless. So that’s why you have complementary descriptions of these different phenomena that are used in very different terms and superficially incompatible – and maybe not only superficially but just plain incompatible – but, in any case, appropriate for answering different kinds of questions.