Night Science

7 | Michael Strevens on how science really works

Itai Yanai & Martin Lercher Season 1 Episode 7

In this episode, Itai and Martin talk to New Zealander Michael Strevens, who – after studying mathematics and computer science – became professor of philosophy at New York University. Michael recently published an amazing book on the scientific method, which not only manages to reconcile crucial ideas by Karl Popper, Thomas Kuhn, and Paul Feyerabend, but is also immensely readable. In this episode, he discusses the main ideas of the book with your hosts, including the crucial difference between what scientists say in their official communications and in the privacy of their labs, what makes modern science such a powerful “knowledge machine”, and why it took humanity 2000 years after Aristotle to get there.

For more information on Night Science, visit www.night-science.org .

Michael: There's something very strange about the situation that scientists are saying, on the one hand, beauty is incredibly informative about which theories are right and which are wrong.



Michael: And on the other hand, our official means of arguing with one another about which theories are right and which are wrong is not allowed to appeal to beauty.



Michael: So there's lots of incredibly valuable information that you're not allowed to consult.



Michael: That's what I take to be, strictly speaking, irrational.



Itai: Welcome to the Night Science Podcast, where we explore the untold story of the scientific creative process.



Martin: We are your hosts, I'm Itai Yanai, and I am Martin Lercher.



Itai: Welcome everybody to this episode of the Nightcast, Nightcast, the Night Science Podcast.



Itai: We are thrilled to have today with us Michael Strevens, who's a professor of philosophy at NYU, New York University.



Itai: Michael was born and raised in New Zealand, where he started his university training.



Itai: He studied mathematics and computer science, but then he switched over to philosophy as he saw the light.



Itai: He did his master's and PhD in that.



Itai: And for the last  years, he's been writing about philosophy.



Itai: He received a Guggenheim Fellowship in , and he lives in New York City, where he's actually my neighbor, and we go sometimes for coffee.



Martin: Yeah, so like Itai said, Michael does many interdisciplinary things.



Martin: And maybe that has to do with this training in mathematics and computer science, which is very different from philosophy in some ways, but has interesting overlaps, as you can see from his work, I think.



Martin: His academic work is principally concerned with the nature of science.



Martin: And he recently published a book called “The Knowledge Machine”, which is written for a general audience, where he explains why science is so successful at creating knowledge.



Martin: And why it took so long for humans to figure out how to do it right.



Martin: And Itai and I loved the book so much that we wrote a review of it for the journal Science.



Martin: So welcome, Michael.



Martin: We are very glad to have you here today.



Michael: Thanks.



Michael: Great to be here.



Martin: Fantastic.



Martin: So to jump right in, Michael, in your book, one or maybe the core idea there is the idea of the iron rule of science.



Martin: Can you explain to our listeners who maybe didn't read your book briefly what this is about and why it's so important?



Michael: Yeah, sure.



Michael: So the iron rule simply says that all official argument in science is to be conducted using arguments based on empirical evidence.



Michael: So if you're going to make a case for your theory or against some rival's theory, it's got to be on the grounds of some sort of empirical test, which is to say some kind of observable fact that one of the theories does, the other doesn't predict or explain.



Michael: So it's a very simple statement of something that I think everyone already has a sense of as a guiding principle in science.



Michael: My work is not so much, I think, in pointing out the existence of the rule, but pointing to its particular functions and also to the sense in which there's actually something rather strange about it, in virtue of which it executes those functions so well and makes science such a powerful thing.



Itai: Yeah, you know, that's really interesting that you sort of boil it down to something so simple.



Itai: I think if you ask the average scientist what they think is the scientific method, they, of course, will bring up Popper.



Itai: The idea of Popper is just that what scientists should do is eliminate ideas, that you should always try to falsify and throw out all the bad ideas so that over time only the right ones will remain.



Itai: And that has forever guided how scientists view science, but you indicate a lot of flaws in this way of thinking.



Michael: I think that Popper is articulating his own, if you like, personal version of the iron rule.



Michael: That is a particular conception of what it is to implement science by doing a certain kind of test.



Michael: And insofar as he's on board with this idea that science all hinges on empirical tests, and really he's one of the great advocates of that idea, then I agree with him 100%.



Michael: I think most philosophers of science these days agree with me that the particular way that he articulated the rule is not quite right.



Michael: And it's an important kind of not quite rightness, because it implies that there can be a kind of objective test of a theory whose validity all scientists will recognize at the time, and therefore that the whole logic of science is something that is an objective matter, that as long as scientists follow this rule, they'll all agree with one another about what the evidence says about the theories.



Michael: Just to be a bit more specific about what Popper says, he says theories make predictions when we observe a prediction that a theory gets wrong, then we throw away the theory, which of course no one does.



Michael: Well, precisely because there's so many things that can go wrong in scientific testing that are not the theory's fault.



Michael: In fact, I think in most science, most of the time, those things are going wrong.



Michael: So when scientists are trying to figure out how to interpret evidence, they're constantly asking themselves, well, you know, what else could have gone wrong with the measuring apparatus?



Michael: Or maybe this particular technique for analyzing things wasn't applied properly.



Michael: Maybe somebody made a mathematical error, especially in the pre-computer days.



Michael: Or maybe we're making some other assumption about what's going on here, which isn't quite right.



Michael: And the reason that everything is a little off is not the theory itself, but this other assumption about the way the world works.



Martin: This is really interesting because Itai and I both have heard this phrase, Popper is really all we have, right?



Martin: Which is how a lot of scientists think about the philosophy of science.



Martin: So it's interesting to realize how he's wrong in such a fundamental way.



Michael: Yeah, I think it's interesting that Popper has been so influential.



Michael: I think a part of that is because scientists, of course, know what they're doing when they're asking themselves all these questions about the apparatus and so on.



Michael: So I think they sometimes barely even notice that what Popper is saying can't be quite right.



Michael: And they just hear him as saying, it's all about testing, that is, it's all about the iron rule.



Michael: And that is exactly right.



Michael: So the bit of Popper that is so attractive to many working scientists who are not inquiring deeply into the intricacies of his thought, the part they're agreeing with is they rightly agree with.



Martin: You talked a little bit about the iron rule just now.



Martin: But to me, what you didn't emphasize enough and what you emphasize very much in the book is how the iron rule only applies to our official communications.



Martin: So if scientists write a journal article or present their work at a conference, then they do this along the iron rule.



Martin: But when they're in their own lab and talking to their students or their close collaborators, then they work according to totally different rules or probably no rules at all.



Michael: Yes, sure.



Michael: What you say is exactly right.



Michael: What's important here is the restrictive nature of the rule, which is saying just the evidence, only the evidence, which above all applies to actual, I call it official scientific argument.



Michael: And what I mean is things that are published in the official scientific record and journals and conference meetings and so on.



Michael: So it's here that there is this 100% relentless focus on evidence.



Michael: But outside of those particular channels, scientists are free to think what they want.



Michael: And in particular, an example I often use is physicists, especially theoretical physicists who are consumed with the guiding power of beauty in theory.



Michael: So insofar as they're participating in the official scientific testing process, they have to find tests of their theory that can be performed in particle accelerators or whatever, dig up empirical evidence.



Michael: They're very much moved, if we believe their personal reports, and I think there's no reason not to, by elegance, symmetry, these other kinds of considerations.



Michael: And the iron rule is saying that stuff will have none of it in the official publications.



Michael: It's all got to be about observable fact.



Itai: You know, Martin and I have a disagreement about what you mean.



Itai: And we thought we would ask you, you're just the perfect person to settle this disagreement.



Itai: The disagreement goes like this.



Itai: As I understood it, there's a reason why the iron rule works so well.



Itai: And that's really what you're trying to say, that the reason it works is because the bringing of empirical evidence doesn't really settle any score.



Itai: It doesn't really falsify anything.



Itai: In contrast, you call the iron rule the perpetuator in chief.



Itai: In other words, it just perpetuates an argument.



Itai: And so it seemed to me that your insight into how science works is that, take these scientists that each have their own agendas, each have whatever is going on in their heart and all their ambitions, and just have them channel that to creating empirical evidence, creating data.



Itai: And over time, it will just be obvious what is true, that this theory is wrong, that this is right.



Itai: And that's sort of what the iron rule allows you to achieve.



Martin: So that is Itai's interpretation.



Martin: So my interpretation is slightly different.



Martin: And that is, I see it as two different aspects.



Martin: The way I understand it is the iron rule, which says you can only argue with empirical evidence.



Martin: The iron rule is what makes science work, period.



Martin: And in addition, it gives an incentive for data collection, but that incentive is not essential for science to work.



Martin: It just gives you a very useful positive feedback loop, because you create more data, so you can do more empirical argumentation.



Martin: But I see this as two different aspects.



Martin: So how do you see it?



Itai: Yeah, and the answer is?



Michael: Well, that's a tough one, because everything that you've said sounds right in some way or other.



Michael: I'll tell you how I see it, and then you tell me who's right.



Itai: In other words, you yourself, Michael, are the perpetuator in chief.



Michael: That's right.



Michael: My desire is just that we continue arguing.



Martin: Well, a typical philosopher.



Michael: So I think in science is really these two processes that are going on at once.



Michael: One is the thinking process, where scientists are constantly evaluating the evidence and thinking about how it bears on the hypotheses that they're interested in.



Michael: And the other is the process by which the evidence is actually generated.



Michael: Without that, there'd be much less to think with.



Michael: I mean, we would still have aesthetic arguments and philosophical arguments, but history suggests that they're not going to take you so far when it comes to figuring out how the material world actually works.



Michael: So these two processes are running in tandem.



Michael: The iron rule is essential to one of them and not to the other, as you'll guess that one it's essential to is the creation of evidence.



Michael: Now, maybe essential is a little too strong here, because certainly the ancient philosopher scientists who were thinking about the world before modern science and the iron rule came along were generating evidence.



Michael: But they were generating evidence that turned out to be, although not useless, not nearly enough to push theoretical thinking along in the right kinds of directions.



Michael: We look at the history of science and we see individual discoveries that are really kind of interesting, but the course of thought is rather surprisingly meandering.



Michael: And of course, historians disagree about this, but it's hard even to discern an overall arc of progress about thinking about, say, physics or chemistry or biology running from Aristotle up until the beginning of the scientific revolution , years later.



Michael: Then suddenly everything changes and it's like everyone gets on course.



Michael: Of course, not sailing in a direct line for the truth.



Michael: It's not that simple, but there's this real change in not just the tempo, but the quality of knowledge production, I think, anyway.



Michael: And we look around and you see the fruits of all of that.



Michael: So to create the right kind of evidence, we need the iron rule because it's the iron rule that by restricting scientists in their official argument to producing evidence gives them the motivation to focus on these tiny little facts that turn out to be the crucial ones.



Michael: So meanwhile, scientists are thinking about all of this stuff.



Michael: They don't think with the iron rule.



Michael: They think using all of the tools of human thought.



Michael: The iron rule is not even a thing that tells you how to think about the evidence.



Michael: In some sense, it just says make more of it.



Michael: It's a little bit more than that, but that will do for now.



Michael: So the iron rule is not essential to this thinking, but the thinking wouldn't get science very far unless it was using the evidence that iron rule is essential, at least in producing.



Michael: So in that sense, the iron rule is essential to all of science.



Michael: And I feel like what I've done there is said some things which echo both Itai and Martin's stories.



Itai: So we're both partially correct.



Martin: Science is bigger than each of us, apparently.



Martin: So, you know, you emphasize this nature of modern science that forces people to collect extraordinary amounts of extremely detailed data, and from this, you seem to conclude that being a scientist is mostly quite boring, right?



Martin: You just have to focus so much on doing the same experiment again and again and doing it just a tiny bit better than last time.



Martin: And this is why we need hobbies.



Martin: And I'd like to quote one thing from your book where you say, the modern science education transmutes the iron law of explanation into a leaden law of scientific thought.



Martin: So that it encourages students not to be creative in their scientific thinking, but to really just focus on the tedious work of collecting data.



Martin: Is that really how you see current science?



Michael: Well, I guess there's two questions here.



Michael: One is about science and one is about science education.



Michael: So about science itself, there is the boredom, but also I think there's a lot of frustration and something that's maybe a little bit different again, which is just a kind of dauntingness.



Michael: As you know, often to get some kind of system up and system could mean almost anything here, but just a kind of a tool that a scientist can use for investigation.



Michael: So it could be a theoretical tool.



Michael: It could be a piece of experimental apparatus.



Michael: It could be some giant complex that's built in the middle of the desert somewhere.



Michael: To get those things up and running is tremendously challenging and complicated and takes a long time.



Michael:  Minutiae of doing it, no doubt, sometimes boring and sometimes not.



Michael: But I would emphasize just the thought at the beginning of a project like that, looking at it, the thought that it's just too much.



Michael: Now, of course, it's not too much.



Michael: Scientists do throw themselves into these projects.



Michael: And really the central thesis of my book is that the iron rule is crucial for motivating this behavior because it doesn't give them any other kind of outlet for argument.



Michael: So my contrast is everything that happened up until the scientific revolution.



Michael: Our subject matter here is not some kind of ideal, rational being, some great inquirer with infinite reserves of patience and so on, but real human beings.



Michael: And we see even some of the most exemplary thinkers did not have that kind of patience or willingness.



Michael: I mean, maybe even especially the most exemplary thinkers didn't have that commitment to just year after year building something, this kind of thing that has to be built to make the very little detailed observations that ultimately, for example, tell us what the right theory of the nature of gravity is.



Itai: In this respect, I think you do acknowledge that your thinking is consistent with that of Thomas Kuhn because the scientist receives a kind of safety net in which to work with.



Itai: I think you disagree with many other things that Thomas Kuhn wrote about, but that you do have in common, don't you say?



Michael: Yes, absolutely.



Michael: In fact, it's more than just a kinship.



Michael: It was really reading Kuhn that gave me this idea that it's critical to the functioning of modern science, that there's a kind of institutional structure that makes it possible for relatively ordinary people to conceive of giving over years of their life to these kinds of projects.



Michael: So as you say, one part of it is simply that there's no other option.



Michael: If you want to do science, then because of the iron rule, you must publish evidence.



Michael: Therefore, however much you're privately guided by theoretical beauty or whatever, in the end, you have to come up with ways of doing experiments and either do them or persuade other people to do them.



Michael: So there's that kind of negative aspect of it.



Michael: But then there's also this more positive aspect that the rule creates a very stable foundation for throwing yourself into that project.



Michael: And this is an aspect of the rule I haven't really talked about so much.



Michael: By laying down a criterion simply for what counts as empirical testing, the kind of observable fact that would bear on the theories without fully telling you how to interpret those facts.



Michael: So you don't have to worry about the rules.



Michael: You don't have to worry that your world is going to fall apart.



Michael: All you have to do is worry about playing the game really well.



Michael: It offers a kind of a floor even as restrictions act like walls that funnel all of the activity of playing the game into the production of evidence.



Martin: So Michael, you said earlier in this discussion that the iron rule doesn't tell you how to think or how to reason.



Martin: And as you know, this podcast is mostly concerned with creativity in science, which is not really what the iron rule is about, right?



Martin: It's certainly not about creativity.



Martin: So what is your perspective on this?



Martin: What do you have to say in the book on creativity or on the way to do science outside of the iron rule?



Martin: Or maybe if it's not in the book, what would you think about it outside of the book?



Michael: Well, it's true that it's not discussed in the book at all.



Michael: There are many chapters, in fact, that were cut out of the book to create something that was a rather more reasonable size.



Michael: And there was one on creativity, but I wouldn't say that I got to the bottom of that very deep world.



Itai: Your chapter on beauty comes close, didn't you say?



Michael: I suppose so, in the sense that it describes some ways in which the pursuit of beauty has given scientists new ideas about the way the world works.



Michael: Yes, that's true.



Michael: So there's a little bit there.



Michael: But that chapter is more concerned, of course, with the question of whether beauty is helpful in finding the truth, despite the fact that many prominent scientists find beauty to be extremely revealing.



Michael: Nevertheless, they must, if they're going to argue for their ideas, put aside all of those concerns and just focus on the evidence.



Michael: However, creativity.



Michael: So it's not something I say a lot about.



Michael: It's obviously very important to science to have new ideas come along when they're needed.



Michael: My own view about this, insofar as I have anything useful to say at all, is that diversity is very important here.



Michael: We can't rely on a few geniuses who seem to have these bottomless minds from which they can fish up just about anything that's needed.



Michael: That sort of Einstein-like character who somehow has the capacity to have the right thought about almost anything.



Michael: Instead, what you have is a huge range of smart, interesting, creative scientists who have just a few ideas.



Michael: And some of them are lucky enough to have the right ideas, and some of them are not so lucky.



Michael: Science, however, is happy as long as somebody out there is having the right idea.



Michael: And so what we really need for creative science is really to have a lot of scientists who at least have some thoughts about what to do next.



Itai: What I thought is so beautiful about the book is, and just as you said, the iron rule gives you rules of engagement.



Itai: You use that exact analogy.



Itai: If science is like chess, then the iron rule are the rules of chess.



Itai: The knight moves in this way and the rook in that.



Itai: And really, it's how scientists should interact.



Itai: What is not covered is what happens in the mind of each participant within the scientific process.



Itai: Where are they generating their ideas?



Itai: Where does their intuition come from?



Itai: You say that maybe the lives of scientists are boring and they need hobbies, and it takes years and years to calibrate the instrument.



Itai: I can see where you're coming from, but if you go into the mind of each individual scientist and see what are they thinking, you know, it's like in my mind, at least it's a roller coaster ride.



Itai: It's what Richard Feynman called “the joy of figuring things out”, the process of realizing that you just learned something is so tremendous and kind of addicting as well.



Itai: So in that respect, it's anything but boring.



Michael: Yes, I quite agree.



Michael: And so a part of what the iron rule is doing is it's forcing scientists to stop doing that interesting stuff, to tear themselves away from the joy of figuring stuff out and actually go into the lab and do all of this other work, which is sometimes tedious, not always, to actually test the ideas that they've had so much fun devising.



Itai: You know, one thing we didn't say yet, but I think it has to be said, is that this book is just a joy to read in terms of, not the philosophical sides that we've been covering, but just in a history of science perspective.



Itai: I mean, you take us on this tour of all these personalities, all these projects, just a crazy cast of characters, and Newton and Descartes figure prominently, and it's just amazing.



Itai: I'm wondering how you thought about your strategy for writing this book because you have a kind of new philosophical idea about how science works.



Itai: It's a very ambitious book.



Itai: You claim that you solved the great method debate on what really distinguishes the scientific process from a non-scientific process, and really you write it for the general reader.



Itai: So how did you come up with the idea for doing it this way?



Michael: That's a good question.



Michael: In my normal professional life, I'm a philosopher and we philosophers tend to stick to our abstractions.



Michael: And if somebody has an example, everyone is so grateful that there is one example that they can go on for years and years just using that single example, which can get quite tedious.



Michael: Plus, of course, a single data point is seldom revealing of everything that's important for the question that's on the table.



Michael: So I do find that it's been very useful for me in thinking about science to travel widely through the sciences, so to read about geology, to even get involved in doing some cognitive psychology, and not just focus where a lot of philosophers gravitate, which is physics, especially fundamental physics.



Michael: So that's been important for my own thought.



Michael: In telling the story, though, I think the answer to your question might be a somewhat more utilitarian one, which is that most general readers don't have much patience for pure abstraction.



Michael: So almost any idea is better when it's presented in the guise of a story.



Michael: And the thing is the same readers who don't have much patience for abstraction are actually very good at getting the general moral from a particular story.



Michael: Plus, it's just really turned out to be quite fun to write those stories.



Michael: It's quite a lot of work to do the research that's needed to get from the kind of half-formed mythical version that I have had in my head when I started writing to a story which actually does justice to the real and pretty interesting characters who are involved.



Michael: But also, actually telling the story turned out to be really quite enjoyable for me, as well as I hope, of course, for my readers.



Martin: Oh, definitely.



Martin: Michael, I would like to go back a little bit to this question of creativity and the question of how do different scientists actually do their day-to-day science or maybe night-to-night science, I should say, in the context of this podcast.



Martin: So, in a way, it seems like on this question, you agree with what Feyerabend would have said, that there is no method beyond the iron rule and just everybody does whatever they think works for them or whatever they're used to.



Martin: And it's just when they write it up for a journal that they have to bring it into the shape of the iron rule.



Martin: Is that how you see it?



Michael: Yes, that's not a bad way of putting it.



Michael: Of course, for Feyerabend, there was no iron rule either.



Michael: So even in the journals, it was all just a kind of improvised logical free-for-all.



Michael: So I don't think that.



Michael: It's more like, as you say, Feyerabend and private Popper in public, I suppose.



Martin: Yeah.



Martin: That's maybe a very succinct summary of the book.



Itai: You know, if we think about the iron rule, it seems as though there's going to be this kind of deterministic path to science.



Itai: You call it the Kuhnian convergence, in that over time, whatever disputes occur, as long as the scientists are collecting data, they will converge upon the right answer.



Itai: And you highlight a lot the notion of different personalities and how that comes to bear on the course of the science.



Itai: I wonder if you've heard this Nobel Prize on quasi-crystals, the  prize and the whole history of this?



Michael: I'm not sure that I do.



Itai: So this is a researcher, Dan Schectman.



Itai: I know this story well because he works at the Technion in Israel where I was a faculty.



Itai: And for many years, Linus Pauling, the great scientist, would make fun of this notion of quasi-crystals that Schectman was promoting.



Itai: For example, he would say, there's no quasi-crystal, there are only quasi-scientists.



Itai: And evidence was accumulating, but because Linus Pauling was against it, it never got any traction.



Itai: And you know this phrase that science progresses one funeral at a time?



Itai: Yes.



Itai: So that's exactly what happened in this case.



Itai: Linus Pauling died, and as soon as he died, a lot of other scientists came up and said, you know, we also sort of observe this quasi-crystals and we could never say to Linus, but yeah, we think that's kind of true.



Itai: And of course, the rest is history.



Itai: It then became a huge discovery and was awarded the Nobel Prize.



Itai: So I think you show many examples of this in the book where personalities are essentially delaying progress rather than promoting it.



Michael: Right.



Michael: I guess one example I mentioned in the book is George Gaylord Simpson, who was very opposed to continental drift.



Michael: And to a surprising extent, it's like Pauling, he was such an imposing figure in the field, especially in the American side of the Atlantic, that people just weren't taking the theory seriously.



Michael: Of course, ultimately, many of the key scientists in the great synthesis, the whole theory of tectonic plates, were in fact North American scientists.



Michael: And this is only  years later.



Michael: But I guess that's when we're talking about the influence of humans and their biographies.



Michael:  years is a long time between somebody being at the apex of their influence and completely gone from the scene.



Martin: One of the strong points you make in your book is that you think you have an explanation of why it took so long for modern science to rise.



Martin: And you're arguing, and even in the subtitle of your book, that the idea of the iron rule is totally irrational and unreasonable.



Martin: But you know, maybe Itai and I were so immersed in this culture and this paradigm of modern science that it's hard for us to really appreciate that.



Martin: Can you help us?



Michael: Yeah, I think it's hard for everyone to appreciate it, even though in some sense, I think it's obvious.



Michael: So let me go back to the case of beauty again.



Michael: And I think the case of beauty is valuable because many of these Nobel Prize winning theoretical physicists, they've really laid out on the table how important they think beauty is as a guide to truth.



Michael: So say things like, if a theory isn't beautiful, it can't be right.



Michael: They express a really deeply felt view that theories can be judged, maybe not wholly, but to a considerable extent on their aesthetic qualities.



Michael: Meanwhile, the iron rule is saying when you go out into the fray and you argue for or against your theory, considerations of beauty don't count at all.



Michael: You're simply not allowed to raise them in print.



Michael: It's all got to be done on the basis of prediction, explanation of observable facts.



Michael: These physicists all know this.



Michael: None of them would disagree with the word I just said.



Michael: Yet, there's something very strange about the situation that scientists are saying on the one hand, beauty is incredibly informative about which theories are right and which are wrong.



Michael: On the other hand, our official means of arguing with one another about which theories are right and which are wrong is not allowed to appeal to beauty.



Michael: There's this loss of incredibly valuable information that you're not allowed to consult.



Michael: That's what I take to be, strictly speaking, irrational.



Martin: Yeah, but I think beauty is a special case, and you even have a chapter on beauty in the book.



Martin: I would argue that maybe the theoretical physicists believe that beauty is so important just out of experience.



Martin: If you write down Maxwell's equations, they're so short and so beautiful, and symmetry plays an important role in physics.



Martin: So I think there's just experience which shows that beauty is a feature of many important theories.



Martin: But apart from beauty, can you give another example where we can see how the iron rule is irrational?



Itai: Well, actually, before we leave beauty, I just want to say one thing.



Itai: In my mind, there's no contradiction at all with physicists' fascination with beauty and also their recognition of the importance of bringing empirical data.



Itai: The lingo of Martin and I, it's just day science versus night science.



Itai: The iron rule is day science.



Itai: You have prediction, you have to test it.



Itai: But beauty gives you such good intuition for generating an idea.



Itai: Beauty, you detail one episode in the book where beauty led to an amazing prediction that could then be tested.



Itai: So it's just, in my mind, the two sides of the coin of science, idea generation and idea testing, where the iron rule, everybody agrees, it's part of the idea testing, where everybody should agree.



Michael: That sounds right to me.



Michael: So the irrationality of the iron rule doesn't lie in any kind of attempt to forbid scientists from using beauty as an inspiration, because it doesn't have anything to say about that process.



Michael: It says, go ahead, use whatever you want as inspiration.



Michael: It's rather using beauty as a probative consideration, as a tool for judging the rightness or wrongness of a theory.



Michael: And so that activity, as you say, is part of day science, and it's there that you would expect if we were going to use all the good tools that we have at our fingertips that we would use among other things.



Michael: Aesthetic judgments, and yet the iron rule says you're not allowed to.



Michael: So that's where I see the irrationality, or if you like, the violation of the rules of good argument.



Michael: One other example, there are many historical cases when many scientists believe that their religious beliefs also had implications for the way the world worked.



Michael: So they're in a position where there was information about their official scientific subject matter to be found in the truths of religion, and yet the iron rule said, don't bring the truths of religion to bear, just focus on the facts.



Michael: So there, for those scientists, I think the iron rule also would have seemed irrational, saying, here's something that is really important and informative, don't consult it.



Michael: Now, of course, looking back from , we can think, well, maybe it wasn't such a great idea, even just from a narrow point of view of finding the truth to bring religious ideas to bear, because on the whole, religion, whatever its merits, hasn't turned out to be very informative about the kinds of things that science cares about.



Michael: So here's another example which is more contemporary, which is the case of the proper interpretation of quantum mechanics, which I do talk about a little bit in the book.



Michael: So a good case can be made, and many scientists and philosophers have made it, that there's something that's philosophically or logically not quite right with quantum mechanics as it's been understood and applied by scientists over the last hundred years, which is the period of time for which the theory has existed.



Michael: Some would go so far as to say there's a kind of incoherence or inconsistency at the heart of the theory, but it's not an inconsistency that comes out when you're actually using the theory to do things.



Michael: It's not as if you get conflicting predictions or anything like that, so you can perfectly well go ahead and apply quantum mechanics in the way that physicists and chemists and so on apply it and get good results.



Michael: And you do get very good results.



Michael: So you can think of the iron rule here as saying to regular scientists, yes, there may be some kind of philosophical inconsistency here, and you can worry about it quietly, but don't write journal articles about that.



Michael: Don't spend your time debating the merits of the theory as an intellectual construct.



Michael: Just go out and test it, what has happened and being extraordinarily successful.



Michael: Nevertheless, at least to those scientists who see problems, one scientist who famously did and kind of stepped over the boundaries of the iron rule, I think, but he was at that stage such a famous and unique figure.



Michael: I'm talking about Albert Einstein, I'm sure you know.



Michael: He really did express his doubts, but other scientists we know from the work of historians talked about this stuff a lot.



Michael: But in the official publications, for the most part, they just confined themselves to developing the theory as a tool.



Michael: So these are scientists for whom the iron rule is saying, these doubts, although they may be legitimate doubt, should not be a part of the scientific argument about the truth or otherwise of quantum mechanics.



Michael: And then again, there's something a little unreasonable about that.



Michael: On the one hand, yes, these doubts may provide good reason to reject the theory in its current form.



Michael: On the other hand, when you do science, you're not allowed to reject the theory for those reasons.



Michael: If you're going to find anything wrong with it at all, you have to confine yourselves to basically incorrect predictions.



Martin: It's interesting that you mentioned this famous quote by Einstein that God doesn't play dice.



Martin: There's a great book I read on Einstein's role in the development of quantum theory.



Martin: And I wasn't aware of that, even if my first degree was in physics.



Martin: But Einstein is actually, in some ways, the first person who developed quantum theory.



Martin: So I think it's really interesting.



Martin: But he certainly noticed this inconsistency that many philosophers find unsatisfying about the quantum theory.



Michael: Right.



Michael: Officially, Einstein's Nobel Prize was for his work on quantum physics, not his work on relativity.



Itai: I want to go back to something you just mentioned.



Itai: So, you know, if there is this thing called the iron rule, and that is really the key to how science is going to operate, then someone might ask, what exactly executes the rule?



Itai: Who maintains the rule?



Itai: And you give an answer to that in passing, really.



Itai: You don't spend too much time on it.



Itai: But the answer for you seems to be that it's the journals.



Itai: There is the very first journal, which is the Philosophical Transactions of the Royal Society.



Itai: If the journals enforce the Iron Rule, that's how it could be maintained.



Itai: I wonder if you can say more about that, because it's a very interesting idea.



Michael: Right.



Michael: Well, the journals are the arena that the Iron Rule supervises.



Michael: You know, if you like, the journal is the board on which the game is played.



Michael: It's precisely the place where the official results are communicated and therefore where the rule applies.



Michael: So it's very natural that the whole institution of the scientific journal is built up around, among other things, ensuring that the rule is properly applied.



Michael: Now, of course, the journals are basically run by scientists themselves.



Michael: I mean, not necessarily the printing and distribution or the electronic equivalent, but the intellectual side of the operation.



Michael: So you send your paper off to a journal and the editor sends it out to other scientists, just like you, to look over.



Michael: And it's really those scientists in their capacity as journal referees who are responsible for giving a thumbs up or a thumbs down to the research, just on the grounds of whether it conforms to the rule.



Michael: That's one of the many things that they're looking for, whether they would put it that way or not.



Michael: So in a way, it's not so much that there's a separate thing, the journal, which is enforcing the rule, almost like a kind of a judge presiding over science from the outside.



Michael: Rather, the institutional structure of the journal is a way of recruiting scientists themselves to the role of iron rule enforcers.



Itai: It's very interesting to think, and I think if I were an editor, say a Nature journal, I would take a lot of pride in learning what you write, that maybe the whole origin of the scientific enterprise stems from the way that the journals operate.



Itai: So I have a question for you, and this is another one where Martin and I disagree, so you will be the great arbiter.



Itai: You open up this book with a quote from Milton's “Paradise Lost”, and it's very brief, so I'll just read it, and my question will be, why did you choose this particular quote?



Itai: What hidden meaning is there here?



Itai: Here grows the cure of all, this fruit divine, fair to the eye, inviting to the taste of virtue to make wise.



Itai: What hinders then to reach and feed at once both body and mind?



Michael: So this is of course the fruit of knowledge, and I'm thinking of science, and the whole scientific method with the iron rule at its core is hanging there on the tree, and if only we pluck that fruit, then we will have everything, all of the knowledge of the way the world works, the technologies to make it work better and more comfortably.



Michael: As I open the book by saying, it was only , years after Aristotle that modern science got going, that we did in fact taste the fruit.



Michael: So I think it's Eve actually is saying this to herself.



Michael: Why is this wonderful fruit that can make us wise?



Michael: Why shouldn't I just reach out and pluck it?



Michael: And my book is to some extent an attempt to answer that question in a historical vein.



Michael: Why did it take so long?



Michael: For a world that certainly had its share of creative, highly motivated and intellectually powerful thinkers, why did none of them really hit upon the scientific method until sometime in the s?



Itai: Interesting.



Itai: So I have to say that Martin was right.



Martin: Now you owe me a bottle of champagne, I think.



Itai: I do.



Michael: Of course, what's lurking in the background in this particular story is the whole notion that plucking the fruit constitutes original sin.



Itai: You know, there's a quote by Igor Stravinsky, the more constraints one imposes, the more one frees oneself.



Itai: I think that also could have been a quote that serves the same purpose, because really the iron rule, you call it very irrational, I think, in the sense that it's a tremendous constraint.



Itai: You're really adding a constraint to the system, and that turns out to be the secret sauce.



Itai: You become free.



Michael: That's right.



Michael: I suppose Stravinsky was talking about a kind of creative freedom, which is not quite what I'm on about.



Michael: The idea that humans work best under constraint, I think, is an extremely powerful one that applies to all sorts of endeavors, to science, to creativity.



Itai: Science and sonnets.



Michael: Yes, exactly, and to poetry and almost everything else, except, of course, philosophy, where we philosophers will just broke no constraint whatsoever.



Michael: Maybe that explains something.



Itai: Maybe.



Martin: I don't know.



Itai: Michael, if I could ask you a final question.



Itai: You write about the feelings or the view that scientists have of philosophy towards the end of the book.



Itai: In particular, you show a tweet by Richard Dawkins.



Itai: I think it's a very disparaging remark about philosophy.



Itai: Wasn't it about that no philosopher discovered natural selection?



Itai: Scientist.



Itai: He took a real scientist, not a philosopher.



Itai: I see your book as a bit of an outreach project as well, of its other functions.



Itai: It might bring scientists closer to philosophy and not just have a negative view of it.



Itai: How do you see what can be done to not have scientists so against philosophy?



Itai: Or maybe there's nothing to be done because that's just what the iron rule prescribes within your Kuhnian paradigm, just generate data, not philosophy.



Michael: Yes, what the iron rule really says is don't bring philosophy into official scientific argument.



Michael: Other than that, feel free to philosophize away.



Michael: At least that's my interpretation of it.



Michael: And I think that these tweets by Dawkins and various other disparaging remarks are probably best understood because being not so much blanket dismissals of philosophy.



Michael: I mean, it may well be that these particular thinkers, in fact, would like to dismiss philosophy totally.



Michael: But in some cases, at least, I think it's more reminding scientists to keep the philosophy out of the day-to-day business, they and your sense of science.



Michael: So it's a kind of encouragement to keep the philosophy to the nocturnal hours.



Michael: But the way that the discouragement is expressed is as a much more extreme sentiment.



Michael: What I would like is for scientists, on the one hand, see how right they are to keep the philosophy out of the day job.



Michael: There's something about it that has worked out extremely well.



Michael: Well, at the same time, seeing that that doesn't mean that you have to close yourself off to philosophical or really to any of these other concerns the rest of the time.



Michael: And in that respect, therefore, all scientists are free to philosophize as long as they do it in a seemly way, that is in the right time and place.



Michael: It's probably better if most people don't spend a lot of time philosophizing because there's many other important tasks to be done.



Michael: But I would like to think that nobody who really stood to gain something from it would feel like they were somehow professionally forbidden.



Itai: Yeah.



Martin: And I have to say reading your book really benefited me a lot as a scientist by realizing this clear distinction between what scientists do in journals versus what they do in their daily work.



Martin: I mean, I know this from personal experience, but I kind of felt vindicated by reading that that is actually how it's supposed to work, and it's not just that I'm being unsystematic or chaotic or non-scientific in how I think about science.



Martin: So that was really great to read that and to understand that so clearly.



Itai: Absolutely.



Martin: Well, Michael, thank you very much.



Martin: That was extremely interesting.



Michael: Yeah, it's been great fun to talk about this stuff.



Itai: For us scientists taking a pause from our day science work and thinking about the iron rule is for us night science.



Itai: So we would call you a night scientist.



Michael: I guess there's something romantic and attractive about that.



Itai: Wonderful.



Itai: Thank you so much for joining us today.



Martin: Yeah, thank you.



Michael: Well, thank you.



Itai: Can't wait to read your next book.



Michael: Yes.



Michael: Well, it's been great to talk.