How philosophy and chemistry combine | Interview with Dr. Eric Scerri

00:19Contributions made

Jed Macosko: Hi, I’m Dr. Jed Macosko at Wake Forest University and Academic Influence, and today, we have a special guest coming to us from UCLA. His name is Professor Eric Scerri, and he studies the history and philosophy of chemistry. So Professor Scerri, thanks for coming to the show today.

Eric Scerri: Thank you for having me.

Jed: You’re welcome. Well, we wanna know what are the big contributions that you and also your colleagues in this same field have made that have helped people understand things better? What would you say are some of the big contributions?

Eric: Sure. Well, one of the raison d’être for the philosophy of chemistry, the reason why it took off, was that traditionally philosophers of science have tended to concentrate on physics because it’s rightly regarded as the most fundamental science, and when it was realized that they had concentrated perhaps a little too much on physics, philosophers of science went to the other end of the scientific spectrum in a sense, and the philosophy of biology began to develop.

And in doing that, and now philosophy of biology is important because biology is clearly not explainable, reducible to physics, so there was a need to study living systems, and that philosophy, that branch of philosophy developed back starting in about the ’50s and ’60s and ’70s.

Now in doing that, it’s as if they leapfrogged completely over chemistry. So chemistry was left out. Even though chemistry is generally regarded, as I’m sure you know, Jed, as the central science. We chemists love to remind people that we are the central science. And so here’s the central science, that employs more people by the way than physicists and biologists put together as far as I know, and yet it was ignored.

Furthermore, and perhaps more relevantly, there’s a question of reduction in philosophy of science asks whether one field is explainable by a more fundamental field.

So the driving question, one of the driving questions in the philosophy of chemistry has been: Is chemistry fundamentally nothing but physics? Is it explainable from first principles of physics? The usual response has been, yes, of course it is. It’s not that far removed from physics, and physics has had tremendous success in explaining chemistry, for instance, the importance of quantum mechanics in making predictions in chemistry. Therefore, chemistry can be regarded as being fully reduced.

Now on more careful reflection, of course, it’s realized that it’s not as simple as that, and so one of the areas that has been of interest to people in my discipline has been to examine that question more critically, more closely, and to really ask the question not, "Is it reduced?" or "Isn’t it reduced?" It’s not a black and white question, more a question of the extent to which it is reduced: How good is quantum mechanics at making predictions in chemistry, for example?

Jed: But wouldn’t that just depend on the strength of the computers that are used to simulate how quantum mechanics can predict?

Eric: Well, to some extent, yes. And of course, one has to be aware of what’s going on in computational chemistry, but the computational methods can take you so far, but there comes a point where the chemist still has to make a judgement call on whether to use one system or another, and it is as much an interpretation as there is raw computation going on.

Jed: Okay, so obviously, there are lots of different approximations of the true quantum mechanical picture, and a chemist is used to choose between those different ways of approximating things, but in the end, if the computer was big enough, couldn’t they just do everything, sort of ab initio, and make it all work from first principles? Or are you of the…

Eric: Yes. So that brings up the question of in principle or in practice. In principle, if the computer was powerful enough and if we had enough time, then yes, we all assume that physics would be able to explain chemistry and biology and even larger systems.

But that’s such an academic question that… Yes. Let’s say the answer is yes. It doesn’t get us very far. We’re more interested in what we can do at the moment. We’re more interested really in the in-practice question rather than the in-principle question.

05:17Chemistry versus physics

Jed: Well, that makes the question, I guess, more interesting and a little bit easier to answer. Okay, so when does the chemist have to really put on a chemist hat and look through chemistry glasses in order to make the thing work so we can get answers to our questions about, "Does this react this way or that way?" and what are those chemistry glasses and how do they differ from just physics glasses?

So can you tell us a little bit about that? You’ve spent your whole career thinking about that, and I’m sure you have some really interesting insights.

Eric: Well, the chemist, as you’ve hinted at, is used to or has a tendency to use approximations, and is not interested in the clean solving of equations from first principles, for example. And I believe it’s even even true of physicists that if you speak to a physicist and you compare the physicist with a mathematician, they too are more likely to accept approximations.

Incidentally, another aspect of this question, and one that I’ve been particularly interested in, is the educational question. Does one present chemistry as though it were nothing but physics? In other words, do you begin teaching students orbitals, electron shells, and so on? Or do you begin by teaching chemistry itself, and then later in the students’ education, present them with more fundamental explanations?

It does seem more and more as if these days there is a tendency to be, if you like seduced by the physics explanations. And then the thinking that if you teach the students quantum mechanics right from the outset, it will be helpful and they’ll be able to explain and understand chemistry.

And that’s to my mind, and some other people, it misses the point because it misrepresents chemistry and makes it look like chemistry is nothing but physics. So this is just…

Jed: Yeah, I think you’re right about that. I mean, as somebody who’s especially taught thermodynamics and statistical mechanics, a lot of times people wanna just go after thermodynamics with a physics set of glasses and mathematician, probabilistic, statistics way of looking at it, but I feel like you miss a lot of the insights that you can gain by shaping your brain to understand things in a different way, an equally true way, an equally mathematical way of explaining the partial differential equations that go into these thermodynamic properties, but one that preserves for you those glasses that can become so helpful.

Eric: Yeah.

Jed: And if you don’t have those, or if you at least don’t have some people in the world wearing those chemistry glasses looking at the problems, then you will undoubtedly miss some answers, important answers. Is that what you’re kind of saying?

Eric: That’s what I’m kind of saying, yes. Different scientists are working at different levels on the scale of systems, and obviously, the chemist is working at a gosser level than the physicist in many instances, and therefore has to use the tools, the mathematical tools of the approximations that are appropriate to that level. Yeah.

08:42Books published

Jed: Very cool. Well, tell us a little bit about the books that are coming out. You’ve written a bunch of books, but there’s a few new ones.

Tell us what do you have coming out soon?

Eric: One book that just came out is a second edition of my, perhaps my main book, which first came out in 2007. The title was and still is, The Periodic Table: Its Story and Its Significance, which is another way of saying its history and its philosophy.

But in order not to put too many people off because philosophy especially tends to frighten the general public and even scientists who… Many of whom regard philosophy as something of a waste of time. There are many famous scientists who have said as much. I could name a few.

Steven Weinberg, the physicist, has a long-standing controversy about the usefulness or otherwise of philosophy. Peter Atkins, the famous chemist, and an author also has made a thing of saying that philosophy of science contributes nothing to science. And interestingly, these people spend a lot of time philosophizing about science, but…

Jed: Oh definitely. Well, we’ll talk about them later. I wanna hear a little bit more about the other book that you said is coming out.

Eric: Okay. The other book that’s coming out is called What Is An Element? Now, we all think we know what elements are, but again, there’s a long and rich story that exist here. Let me just briefly touch on it.

When somebody points, let’s say at carbon on the periodic table, what do they mean by claiming to talk about carbon? Do they mean diamond? Do they mean graphite? Do they mean C60? No, they mean carbon, the abstract element carbon. Similarly, when we say carbon, do we mean carbon-12, carbon-13, carbon-14? We don’t mean any of those individual instances of carbon, we mean carbon, the element.

So that has a deep significance in the philosophy of science, that very question. There are two senses of element. There’s element as the abstract concept, which does a lot of work in science, even though scientists, chemists often want to deny that the abstract concept does any work. And then there’s the element as to what’s called the simple substance, this thing that you can put in a jar, in a bottle, and that you can actually experiment on.

So that whole dynamic about what those two different meanings are is the subject of this most recent book. It’s actually an edited collection. We have different people expressing different views on this.

Jed: Wow, that sounds fascinating. And when is it due out?

Eric: It’s just come out.

Jed: Wonderful. That is really exciting. Well, we look forward to putting a link on our website so that people can find that fascinating book.

Eric: Sure, fine by me.

11:51What’s next?

Jed: And now that you’re done with editing that volume, what’s next? Do you have other volumes you wanna edit or a book you wanna write yourself?

Eric: It’s funny, maybe this has something to do with the current pandemic, but for the first time in 20 years, I’m actually not actively writing a book. And it feels good, but of course, I’m inevitably planning new ones.

I’m getting together with a molecular biologist at UC Riverside and we’re planning to write a book comparing Darwin’s discovery and Mendeleev’s discovery.

Jed: Wow.

Eric: Because there are many parallels and differences. Their main books were published 10 years apart. Darwin’s opus magnus was 1859, Mendeleev’s book was 1869.

Their discoveries were made in a sort of conceptual way, there was no fundamental explanation for why evolution occurs, there was no fundamental explanation for why the periodic table is what it is.

And of course, as history has unfolded, we now have a whole genetics background to evolution. We have the discovery of DNA to explain biology at a fundamental level, and in the case of the periodic table, the discovery of atomic structure, the electron, in particular, electronic structure, which provides a fundamental explanation for the periodic table. So we want to trace that development.

13:26How scientific discoveries are made

Jed: That is absolutely fascinating. I hope that book comes out soon. I’m sure it’ll be a lot of fun to work on.

Well, is there anything else that you think is important, as people watch videos on famous chemists, famous other scientists, that you as a philosopher of science and a historian of science want to share?

Eric: Yeah, maybe, and this is the subject of another book actually. I happen to have a copy here ’cause I was looking something up before. A Tale of Seven Scientists, because I have the view that multiple discovery in science has happened very frequently.

Scientific disputes happen very, very often, so I’ve tried to reach an understanding of why that might be, and in doing that, I am of the opinion that scientific discoveries are not made by one or two individuals, but they’re made by numerous individuals, all working away, all chipping away, and that this contributes to the overall development of science, and I call it an evolutionary account of science.

I disagree with Thomas Kuhn’s view that there are revolutions in science, because if there are revolutions, then presumably there are very decisive steps, and this is an idea which has been made famous by Thomas Kuhn, the logic of… What was the title… The Structure of Scientific Revolutions. For me, it’s not a matter of revolutions, it’s a matter of evolution, and I see that the importance of what I call the little people, minor contributors.

For example, when Bohr developed the Bohr model of the atom, he drew heavily on the work of John Nicholson, almost completely unknown unless you’re a physicist with a special interest in the history of atomic structure. In chemistry, there have been numerous cases.

When atomic number was discovered, this is usually attributed to Moseley, the British physicist. Well, there was a Dutch economist, as a matter of fact, called Van den Broek, who really was the first to suggest that the elements should be ordered according to atomic number, or to the charge as it corresponds to the charge of each atom. Almost completely unknown, and yet he did some ground-breaking work.

So I’m arguing for the role of the little people, and I’m arguing that science is really a collective enterprise, although not consciously collective. Of course, there are teams of scientists more and more that work on things, but I’m talking about the fact that even though these people appear to be working in isolation, they’re all contributing to the overall development of science.

So if you like, it’s my own view of the philosophy of science. It’s become less and less fashionable to try and understand the nature of science as a whole. It’s usually thought to be too difficult a problem, so I’m attempting what’s regarded in philosophy of science as the impossible, to describe the nature of science.

Many people have tried: Popper, Kuhn, Feyerabend, Lakatos, etcetera, etcetera, etcetera. Nowadays, the field has fragmented into one looks into causation or reduction or emergence or one of the… And of course I do that as well, but it was nice to have a crack at the big question.

Jed: The big enchilada, as we like to say. [chuckle]

Eric: The full monty, as we say in England.

Jed: The fully monty, yes. [chuckle]

So how do the seven scientists fit into that amazing thesis that you just laid out for us?

Eric: They are seven very little known scientists who I believe made key contributions. One of them is Nicholson, the other one is Van den Broek, that I mentioned.

17:23Sign off

Jed: Absolutely fascinating. Well, the whole thesis sounds really cool, and of course, Thomas Kuhn has made a huge impact in people’s understanding of how things move forward, and I hope that this book continues to gain popularity and shape people’s view of how science has moved forward, the conversation of science.

Very, very cool. Thank you so much, Eric, for coming on this show. It was really fun to have you as our guest, and we appreciate you taking the time to spend with us.

Eric: Thank you, Jed. It’s been fun. Thank you.