Alan Saunders: Let's say you go to a university campus. There you see the brand, spanking new science building, paid for with public money and a bit of private investment, all plate glass, concrete and steel. A little way down the road there's a rather shabby, brick building from the '40s. That's where the philosophers live.

But hey, the philosophers are talking about science, and sometimes not just talking about it but actually seeming to lay down the law about it. They appear to be telling scientists how to go about their jobs.

But is what they're doing really relevant to what the scientists up the road are doing? That's what we're talking about today on The Philosopher's Zone. My name's Alan Saunders and I'm joined this week by James Franklin, Professor in the School of Mathematics and Statistics at the University of New South Wales.

Now some scientists, Newton for example, and Einstein, have certainly made some philosophical remarks, but what is the difference between science and philosophy?

James Franklin.

James Franklin: Scientists can of course do philosophy of science as well, but it is certainly a different discipline, somehow more general than what is done in science. So we have I think all a good understanding of what science is, roughly speaking. It goes out into the wet and makes observations and makes theories to explain those observations. Here are a couple of the tasks that philosophy of science does that's over and above that. First of all, it asks about the general nature of evidence: what about the believability of those theories, the relations between the observational evidence and the theories? Is that something objective and how well-established are theories and how well-established can theories be in general, but also how well established are actual theories like controversial ones, and global warming and evolution and so on. It's the business of somebody that can have an overview of science and the nature of evidence to evaluate those kind of things.

Another kind of thing that philosophy of science does, is ask how literally we should take the language of science? So scientists talk about entities like atoms, numbers, forces, space, and so on. Well are those things really there? Or are they just ways of speaking about it, ways of deducing one thing of another? So the real is questioned. So they're just a couple of the examples.

Alan Saunders: Well the question of the language of science is an interesting one because scientists I presume take it for granted that when they're talking about things like forces or space or numbers, this is bread and butter for them, and if you actually ask them whether these things really exist, they're a bit impatient, aren't they, and thinking, 'Why are you asking stupid questions?'

James Franklin: Sometimes they are, sometimes they're not. The physicists that I've spoken to often say there are no such things as forces for example, that Newton's second law (force equals mass by acceleration) are thought by many physicists to be actually the definition of force, that force is just a theoretical entity not to be taken seriously, and all there is to measure is acceleration. I think this is false, here's a quick philosophical argument on why you should be realist about forces: put the tips of your index fingers together and press lightly. Now press twice as hard. It certainly feels like there's a difference, and that's well explained if you think that there really are such things as forces like little pushers in there that you're feeling. So there's no difference in acceleration of course, because the fingers are not moving, so yes, I think that suggests there are forces. But of course there are some philosophical counter-arguments you might make to suggest that maybe you're just feeling a difference in shape or something. But that's the kind of thing they do in philosophy of science that is not really a scientific question; there's nothing to measure, there's no measuring instrument that's going to tell you the answer to that question.

Alan Saunders: Another question I suppose is the difference between the natural sciences and, say, the formal sciences like mathematics, as you say. If you're going to do the natural sciences you're going to have to go out and get wet.

James Franklin: Yes, that's right, it's certainly a question.

Alan Saunders: Whereas you as a mathematician, you can just sit in a warm office, and you don't do anything.

James Franklin: Warm office, playing with my computer screen and that's it! I might run some computer experiments. Yes, I don't have to have vast grants for research assistants trawling the ocean or something. So hopefully philosophy of science should explain what the difference is between natural sciences and the formal sciences like mathematics, operations research, computer modeling and so on, that makes that possible. And that's a very difficult question, but that's certainly a question that needs to be tackled.

Alan Saunders: Is that one which philosophy of science has actually answered, do you think?

James Franklin: No, maybe it's more for philosophy of mathematics, because I think we understand the natural science aspect, we understand why you have to get out to observe what the acceleration due to gravity, or what actually causes anthrax or something, but we don't understand so well the mathematics, why you don't have to observe exactly in mathematics, or maybe you do. I mean do new-born babies need to observe something to count? You do seem to need to manipulate objects to have a basic understanding of counting. But still, it's not like having evidence, you don't exactly have evidence that two and two plus four. If you're really manipulated things and understand why these two apples and these two apples are four apples, you don't need to wonder if it's the same with people or pears or something. There's something different about mathematics that it has a pure understanding that is not available in the physical sciences. We've been working on philosophy of mathematics for 2,500 years and success is hourly expected.

The difficult thing is exactly to explain the feeling of necessity in the mathematics. There appears to be a necessity about the real world, not just about things you've made up. You could easily explain it away by saying 'We've made up all those concepts about number', but that's not convincing, either.

Alan Saunders: But is this a philosophical issue, or is it an issue about human psychology and the growth of human psychology?

James Franklin: There is a potential for explaining it away, so to speak, as something about human psychology, but even there, it's hard to see where you're going to find the explanation because the human psychology looks the same in the case of simple physics and simple arithmetic that the infant just plays around in the world, and gets an understanding of how bodies move and how apples add up, but it's only in the one case that they get the feeling of necessity, and there just doesn't seem any resources in the development of psychology to explain that difference.

Alan Saunders: We're trying to address here the question of the relevance of the philosophy of science to actual science, and it's not clear to me that the relevance of the philosophy of science decides is anything other than annoying scientists, which is a good thing.

James Franklin: It can be, yes. Scientists need to be annoyed.

Alan Saunders: - annoyed.

Alan Saunders: But one of the questions I suppose is that science deals with evidence, but what constitutes evidence?

James Franklin: That's right. It's philosophy that has to tell you about that, and in my view, it tells you that there is a very objective logical concept of evidence. That's the same in science and scientific theorisng with respect to observational evidence. That's the same as in proof beyond reasonable doubt in law. And it's something that the human brain is actually very good at, intuitive evaluation of quite large bodies of evidence. Philosophy of science should tell people that. Whether it's really helpful to real scientists is a little hard to say. It certainly helps them defend themselves against their post-modernist enemies who say that there's no such objective relation and that the scientists are just over-sensitive to such things as political consequences and what will get them the next grant. It's a defensive science but it's something you really need to develop at an intuitive level I think, which you might do by scientific study or equally, historical study because evidence in history works the same way.

Alan Saunders: You take the view that there is a relationship between evidence and theory that is a purely logical relationship. Tell us about that.

James Franklin: Well this is called the objective Bayesian view of evidence, and the classic theorist in this, Keynes, the economist in his Treatise on Probability. He did that in his younger days before he went on to something easier, like economics. It's difficult, but he says that it's the same kind of relation across the board. So to take a reasonably simple example, if you have a basic scientific theory such as that all swans are white, when you go out in the wet and observe the colour of some swans, and if there's a black one, well that's so much the worse for the theory, and back to the drawing board, but if they are all white, that, according to this view of evidence, makes the theory that all swans are white more probable, that's more logically probable, more rationally believable, than it was before. And you might hope to give some number to that, but even if you can't you can say 'That's how science works. It makes predictions, checks if they are confirmed, and if so, well they're more believable than they were before.' And you can say more things like 'If the consequence predicted is very surprising without that theory, then it confirms the theory quite a lot more', and if you have a variety of evidence, that's also a good.

Alan Saunders: Well I have two things to say about that. The first thing is possibly a psychological reaction, but if I have a theory that all swans are white, and I go to Western Australia and there's a black swan, my reaction is not going to be back to the drawing board, my reaction is going to be, 'You call that a swan? Or course it's not a swan, it's black.'

James Franklin: It's a swimming raven. Right OK. But that wasn't anybody's real reaction because the birds in question shared nearly all their other properties including the kind of feathers and their shape and so on with the white swans of Europe. And everybody said, 'Look, they're so like swans except for the colour, we'll call them swans. There's no way to reclassify those inconvenient observations as something else.' In a more complex case you might in fact try that. And of course you might pull your horns in and say, 'Well at least all European swans are white, we weren't as wrong as some of these skeptical theorists maintain.'

Alan Saunders: My other answer is going to be that if we're in an infinite universe and this is drawn from one of my intellectual heroes and absolutely not one of yours, I know, the philosopher Karl Popper, if we're in an infinite universe then no number of white swans are going to confirm the theory that all swans are white, because there could always be a black swan just around the corner.

James Franklin: Well there could be, it's just that it's logically not likely because if there was one around the corner, most likely it would have turned up recently. It's true that we're talking about extent of the universe and extent of the earth, and the distance of the observed swans from the unobserved ones. There are some very tricky matters about spatial reasoning and extrapolation which is a poorly-understood form of reasoning, but extrapolation means extending the range of your predictions if all your observations of what you're trying to predict are in a small region, what about outside that region? So that is certainly weaker than if you have the observations distributed across the board. But I wouldn't agree, even if there are an infinite number of swans, inductive arguments of that kind from all observed swans are white, don't have zero probability as Popper thought. We know that swanness and whiteness and those real universals that are out there and studied by science, can have law-like connections between them.

Alan Saunders: What does that mean, law-like connections?

James Franklin: Well it means that our perceptions and concepts, can so to speak in good cases anyway, carve nature at the joints, as some of the philosophers say, and that whiteness is something real out there, shared by white things, and it's the cause of our perceiving them as white. The same is true of a natural classification such as being a swan, or being a bird and so on, there's right and wrong ways to classify that it's part of the business of science to discover, and once you have these classifications of respectively animals and colours, there can be a connection between them.

It's the aim of science to discover exactly those connections, such as Newton's between the mass of different bodies and the gravitational connection between them. Once you've classified things correctly, you find, and even the baby finds, that there's connections between them that (are) just always there. They're not logically necessary or anything, you can't work them out, unlike mathematics, you can't work them out just by thinking, but once you find constant conjunction between these two things, such as that all swans are white, you infer that there's something out there that's a connection between those. We might attribute it, at this stage as the properties of DNA of swans or something, but that's only moving back one step further. Somewhere there's the way causality works in the world, there's a causal connection between quite small numbers of properties.

Alan Saunders: On ABC Radio National you're with The Philosopher's Zone. I'm Alan Saunders and I'm talking to James Franklin from the University of New South Wales about the relevance, or the irrelevance, of the philosophy of science to science.

Now one of the things we're talking about here is what it is for a truth to be universal. Now that leads us to a very old philosophical distinction between realism and nominalism.

James Franklin: To be realist about some concept is to say that there is such a thing, and it's not just made up by us, whereas to be nomalist, is to say it's just a way of speaking of ours, from the Latin 'nomen' word, just an empty sign. So for example, in the case of forces I was arguing for realism about forces. When you felt them by pressing the fingers together, you would naturally conclude from that that there is such a thing as forces. On the other hand you'd never be tempted to do that with something like the average Londoner. Scientists tell you that the average Londoner has 2.3 children, you're not tempted to think that that's anything except a way of speaking, that there's some individual entity called the average Londoner, that has 2.5 children. So it would be natural to take a realist view of forces, but a nominalist view of the average Londoner. There's this question about all the entities talked about in science. A classic case is numbers, so that's a very difficult one. Are there such things out there as numbers or are they just a way of speaking about the divisibility of things into parts or something?

Alan Saunders: But why do I need to take a realist view of swans? I think that swans are white, all the swans I've seen are white, this is enough to be getting on with, why...

James Franklin: To be getting on with for what purpose?

Alan Saunders: Well for swan identification.

James Franklin: OK, but what does swan identification mean? You would think that it means that swans due to their inheritance or something, tend to have very many properties in common and that they're hence a scientific type that would allow you to predict things, like whether they're good to eat or so forth. Having classified swans you would normally think that unless there's some reason to think the opposite, that they all taste much the same, even though you haven't got much very direct relevant evidence to that. And normally you would think that if all the observed ones are the same colour, colour would normally go with being in a certain species as well. Though colour is not quite as biologically connected to specieshood because of course with plants. there's a good reason why you don't use colour to classify plants because plants tend to share a lot of things but often be different colours even though they're the same species. But that's things for science to discover, and what science is discovering in those cases is whether there are or aren't real connections between being a member of the swan species and other things such as colour.

Alan Saunders: Let's look at how science is sometimes not very good at admitting when it doesn't know the answer to a question. And let's look at the question why is the sun hot? Tell us about that.

James Franklin: The sun is hot as we now know, because there are fusion reactions in the sun that create an enormous amount of energy, according to Einstein's equation e=mc2. So it occurred to me to go and look at an encylopaedia of 100 years ago, a good one, that had had the latest scientific theories and see what they say, because Einstein only discovered that in around 1905, and he discovered it in time to appear in the Encyclopaedia Britannica of 1911, the celebrated 11th edition. Right, I said to myself, what's in the 10th edition about why is the sun hot?

Alan Saunders: We should say that the 11th edition of the Britannica is the one that everybody holds up as being the really substantial and authoritative edition.

James Franklin: Yes it was a quantum leap, as we now say beyond the earlier ones. A marvellous piece of work. Although the early ones were certainly good. So there isn't strictly a 10th edition but there is some supplementary volumes of 1902 added to a 9th edition of 1887. Both of those have an article on the sun. The one in 1887 completely avoids the question of why the sun is hot. It says the sun is so big and it's structure is such-and-such, and there's actually not much at that time to know about the structure of the sun. Quite hard to observe.

A 1902 Supplementary Volume article does mention at least the question of the sun being hot, but you certainly needn't expect it to say the true answer, which is, 'I'm sorry, science hasn't got the faintest idea why the sun is hot', which was the true answer at that time. It says, well it calculates how much heat the sun is losing, and it says that if it wasn't replenished, it would be decaying in its temperature 4% a year, (which plainly it isn't). So then it mentions somewhat embarrassedly, the only possible explanation they might have had at that time on how it was producing this heat, which is contraction. It calculates how much contraction there should be to produce that amount of heat per year, and it's well, quite a lot, but it certainly doesn't go so far as to say whether this is reasonable or unreasonable.

So you don't find science admitting when it hasn't got a clue. And I wonder if there are some more modern cases where science is a little bit more upfront, shall we say, about its marketing, and is justified by the evidence.

Alan Saunders: The question that we're really addressing here is whether philosophy of science is relevant to real science. Is it actually relevant? I mean does it make any difference to what actual scientists do?

James Franklin: Well the more applied parts of it like understanding evidence, they do, but perhaps scientists can pick that up intuitively. Some of the more classic philosophy of science studied in 'philosophy of science' courses such as Popper and Kuhn, the 20th century philosophers of science, I think is not relevant to real science, but that's partly because they got things so wrong. But where philosophy of science I think is very directly relevant to science is deciding the question what scientific questions are interesting. You can see this if you read the writings of some of the early quantum physicists, like Bohr and Heisenberg. They grew up in a philosophy-saturated German environment. It gave them some sense of first of all conceptual difficulties of the subject, which turned out to be extreme once they got into them, but also it gave them some sense of the big picture of what would be a really big breakthrough in science. Whereas I think the typical scientific education of today is not so good on that. You study some science and become more and more specialised and philosophy of science could perhaps expand your mind and make you think along a few different lines that might actually get you the Nobel Prize. Australians have not got enough Nobel Prizes and I wonder if part of the reason is that -

Alan Saunders: We haven't got enough? We have a huge number of Nobel Prizes given the size of the population.

James Franklin: Yes, all right, all right. We're not doing too badly for the size of the population, but I still think we need to expand people's minds a little bit on what would be an interesting breakthrough and how they might think differently and do something a little more interdisciplinary to work out how to think differently.

Alan Saunders: You mention two philosophers of science of whom you disapprove, Karl Popper and Thomas S. Kuhn. Karl Popper wrote a book called The Logic of Scientific Method in the '30s and Kuhn wrote a book called The Structure of Scientific Revolution which I think came out at the end of the '50s. They were both men trained in science. Popper knew a great deal of maths, he knew a great deal of physics, and Coomb was a physicist, he was trained in physics. Where did they go wrong?

James Franklin: Physics is not really ideal training to do general-purpose philosophy of science. You'd be much better off with ornithology or oceanography, operations research or something like that.

Alan Saunders: Something beginning with O.

James Franklin: With O, yes. Just so that you had a feeling for, so to speak, lower level of science where science is much more progressive. Whereas the higher level and more theoretical levels of physics are subject to more revolutionary change. Well what do you expect, because they're at about very deep levels of reality. But you should think more about all swans are white, and the basic classificatory parts of science, and things like regional oceanography, the different kinds of currents for example in the world. A build-up of observations gives us a good feel for what science is about.

Whereas coming from where they did, Popper and Kuhn were both deductivists, meaning that they didn't believe in any of the probalistic logic relation between evidence and hypothesis that I was talking earlier. They believed that, as you were saying about in your example about the swans, that no amount of confirmation of a theory by observational evidence such as observing white swans, could possibly make a theory more probable. Well that's failing to get to square one in the philosophy of science, because it's that relation that makes science what it is and makes science the kind of thing that tells us how to think and tells us how to think truly, and that for example, underpins especially something like drug trials, where you have to have observational evidence that under blind trials such a proportion of the patients are being cured of the disease, therefore that gives us good reason to think that you, the next patient will be cured.

Alan Saunders: So you think somebody like an oceanographer who has to address basic questions like where the land ends and the sea begins, you know, which I presume is a 101 for an oceanographer, would have a better grasp of the philosophy of science?

James Franklin: Absolutely. Yes. They would do difficult observations of currents. Currents are very difficult because fluid is very difficult to predict, but it's not difficult in a way that is going to produce scientific revolutions or something like that. It's difficult just because fluids are, of their nature, very, well they're fluid, and they have eddies and so on that make things difficult to predict, and that's one of the reasons why climate science is a difficult science, and it's that kind of basic relation between evidence and perhaps computer modelling and the theory that is a perfect training in the relation between theory and evidence.

Alan Saunders: James Franklin from the University of New South Wales. His new book, What Science Knows and How it Knows It, hasn't appeared yet, but it'll be along in just a few months.

I'm Alan Saunders, and I'll be along again in just a few days, together with my producer, Kyla Slaven and sound engineer, Charlie McKune. Hope you can join us.