 Good morning, everyone. Well, depending on your time zone. My name is Dan camps. I'm a member of the philosophy faculty here at UC Merced. And it's my pleasure to welcome you to our talk this morning by Charles Pence. First, just some notes on etiquette and procedure. So I've disabled microphones and video for the talk portion, just out of general zoom bombing concerns, although feel free to use the chat as some folks are already. I will know for those of you who are coming from outside of philosophy that the norm and philosophies to say questions until the end of the talk. So Charles, I think might very reasonably choose to just ignore questions posed in the chat. Charles will speak for about 45 minutes today. And then afterwards, I'll moderate questions from the audience using the raise your hand function on zoom, and we'll be starting those with questions from students. Initially, let's see the other procedural point I wanted to note is that the talk this morning is being recorded, although UC Merced philosophy doesn't have a YouTube so I'm not quite sure what we're going to do with the recording, but there is a recording with that, it's my pleasure to introduce our speaker today. Charles Pence is charge a decor, which I guess is equivalent to an assistant professor at the university Catholic to live on in live on the new Belgium, where he directs the center for philosophy of science and societies, which has possibly an acronym that is possibly pronounced suffices. I'm not sure. That's how I pronounce it. Charles also serves as the co editor for the journal philosophy theory and practice in biology or PTP bio is a fantastic entirely open, open access philosophy of biology journal. His work centers on the philosophy and history of biology with a focus on the introduction and contemporary use of chance and statistics and evolutionary theory. His lab is also one of the foremost groups integrating this work with methods of the digital humanities and is increasingly engaged in the ethical implications of biological science and technology. I will also note that Charles has been a good friend of mine for something like 15 years now since we were in graduate school together. Lots of fond memories of vegan potlucks and getting drinks together at one of a really fantastic Irish pub in South Bend, Indiana. So, with that, please join me in welcoming Charles Pence. Great, let me get myself unmuted here. Dan, thanks so much. Yeah, this is this is really, really fantastic invite I really I can't tell you how much I appreciate it and as well thank you all for for being there I see a bunch of actually both delightfully unfamiliar and unfamiliar faces in the in the in the participants list so I'm really excited to see to see you all turn up yes hello from a sort of pale evening from our university campus outside of Brussels, about an hour, an hour outside of Brussels in the French speaking region Hello, welcome. What I am going to be doing tonight, yes or today, sorry, this morning tonight in insert time zone here is talking through the argument of my brand new book, of which you see the cover here came out in paper form about a couple of months ago now. This is the first time I've ever done a 45 minute talk on a 180 page argument. And so, we'll get it. I'm going to do my best. This is a novel thing for me. This is the first book of this size that I've ever written so I'm really happy to work to work through it with you guys tonight. Well, the rest of the remnants of a title slide, mostly to say thanks to the NSF so this was this was work that was partially funded by the National Science Foundation before I before I left the US. Let me start by motivating the project a little bit so what what why am I why am I here. The whole thing comes out for me of noting a simple fact that I draw attention to a lot in a fair amount of work that I do. But I think it's I think it's still kind of kind of interestingly striking and that is when you go back and read the origin of species, which I strongly recommend it's it's an absolutely delightful. You get struck by the fact that a lot of what happens in the origin seems really familiar from a 2022 perspective on the philosophy of the life sciences on evolutionary theory etc. A lot of it reads really naturally it's a it's it's surprisingly contemporary that makes all the more shocking or striking the times when it doesn't seem that way when something happens in the origin, or something's missing in the origin that that that we would expect to be there, and it's not. I have a bunch of these that are actually formed a lot of sort of research topics for various things I'm interested in the history and philosophy of biology but the starting point for this project is to note that there's not a mathematical formula in here, there's not a mathematical formula there's not a statistical distribution there's not a graph. There's one phylogenetic tree that's playing all kinds of really interesting rhetorical roles but there's one phylogenetic tree. It does not take very long at all for this to change so by the time you get to the early 1930s this is one of sewer rights first adaptive landscape diagrams. This is about the distribution of a population in an abstract space consisting of trait values being measured by a property that we now then would call fitness a word that Darwin didn't use. These are mathematics models, they are statisticalized models, they are population models, you get none of that in the origin of species so that happened really quick a contemporary evolution textbook can't make it 30 pages without drawing a graph or something. So how, how did this happen, what happened here, something big happened in, I'm calling it a century from Darwin's first sort of concrete notebook sketches in the 1830s to about 1930 I'll talk more about why I put up put a pin in 1930 in a little while. So why when and how did we make this change. Let me put the point a little more clearly and a little bit more detail. I want to pull on four threads here, things that are either missing in Darwin or missing in some of Darwin's immediate successors. We see the construction of a statistical theory of evolution. It's a theory that could let us understand the action of natural selection so it's a theory that that directly invokes selection that gives us a handle on explaining selective phenomena. It's cross generational. It's described at the population level, as opposed to being about individual adaptations what happens to individual organisms how they get the characters that they get, except indirectly of course. And then another thing that happens in the middle of this century is what has come to be called the rediscovery of Mendel's so Mendel's work happens also in 1830 is largely forgotten or there's a more complicated story here that I could talk about in a Q&A if people are interested but suffice it to say for the moment that it doesn't become historically very significant until about 1901, but after about 1901 any theory of biology worth its salt was going to have to pick up at least some understanding of Mendelian Mendelian transmission. I'm going to have a couple of brief kind of context sections so if you're not super up on the history and philosophy of biology literature on this. I'll get back to my own story in a couple of slides but I, if you are familiar you're going to know that there's a lot written on this, including by people who are in the chat right now. I want to I want to contextualize a little bit kind of some of my foils that I've that I've had in in in developing this this story. The classic source for what's going on in this period is Bill Provines, the origins of theoretical population genetics and this is a really actually really lovely book, meticulously researched a bit cantankerous and unusual because Provine was a bit cantankerous and unusual. But it's really it's really nicely done. I'm going to caricature him a little bit here but I want to pull on a pull on a thread that I think is present in both Provine and some other historians who've looked at this period that I think will kind of comparatively illuminate what I'm up to in this project. On the classic story we can think of the classic story something like this. We start with Darwin Darwin has as I've sort of already alluded to this individualist theory of natural selection. It's a very. So that's that's one important, important facet here Darwin's somewhat concerned with populations but he's not concerned with populations the way that a contemporary biologist or even a historical population geneticist would have been concerned with populations he's got a very individualistic lens. And it's a very good it's what's now come to be called a gradualist theory all organisms get all their characters very slowly bit by bit, right. And those two, those two strands especially the gradualism on this classic story are picked up by comes to be called the biometrical school don't worry more about that in a second but Carl Pearson WFR Weldon or your central figures. Meanwhile, in what's sometimes called an anti Darwinian vein precisely because not gradualist at all, the rediscoverers of Mendel and developers of early genetics including William Bateson sort of relaunch sort of novel efforts to try to build a discontinuous theory of evolution, but and here's the key, the key move the key thing that's happening in this period, according to the classic story is that these guys get into a fight that is so nasty, so bitter, and so in the end it's it is argued meaningless that matters for the history of biology is are a Fisher Sewell right other architects of contemporary population genetics, sort of sift through the wreckage and they pick out what's good in Mendel, and what's good in Darwin, ignore everything that's gone on in between those two points in time and just sort of rebuild evolutionary theory in the 1930s and 1940s starting from nothing. That's the idea here, and you get this in a number of in a number of different histories. I won't read the quotes but Provine and the geneticist Alfred Sturdoven so that's a proper actors history and he was there at the founding of the new synthesis. They look back on this period with a kind of like wistful regret, there's some like nostalgia, like biology could have advanced 20 years in the blink of an eye, but instead we wasted 20 years on this nasty personal fight between Bateson and Weldon in Anderson who just couldn't get over themselves right if only they'd been able to all get along, they could have figured out that they could have all worked together, which is exactly what Fisher and right would have found, or went on to find I should say a few decades later. Now, in short what I want to do tonight is argue against this idea in a couple of different ways I want to present an alternative historical account and philosophical account that I think is more illuminating and more and more interesting than this kind of frame. I'll get there in just a second I have two more quick caveats to give you before I do though. The first thing to say is, despite what you might be led to believe by the title in general structure of the book this is very definitely not a story of the development of statistical method or statistical techniques. I do better than that already between Stigler's Stigler's history of statistics is fantastic on this stuff. Bulmer's biography of Francis Galton is fantastic on this stuff. There are other places that you can go if you want to learn the ins and outs of why Francis Galton developed a particular method of regression in the particular year that he did and what that meant precisely. I'm that's that's that's not the fish that I that I want to fry to fry here. The other thing and this is a bit more complex and a bit stickier is that this isn't a history of eugenics, and that may be a little bit surprising because among the authors that I will talk to you about over the next half hour are Carl Pearson Francis Galton and are a Fisher the sort of trifecta of the developers of British eugenics in the early decades of the 20th century. And so I have a lot to say about eugenics, I think it is an extremely important and interesting part of what's going on here. I also think it's not playing as directly into the story that I want to tell as you might think I think there are some reasons for that. Again, I'm happy to say more. I'm also happy to gesture at really phenomenal work. The historians of eugenics have been doing great stuff in the last 20 and 20 or 30 years. Again, as I said with mathematical statistics better than I would have done it. So I can, the Muslim Dars book is phenomenal, and I can I could I could I could obviously give more references than that. Okay, enough about what other people already did and what I'm not going to do let me talk about what I actually did do. I can say more about relationships between what I'm doing and other projects in the q&a don't that's a that's something I'm happy to talk more about. I could sum up the major theses of the book in two pretty brief slides, actually. So first, I want to push the idea that there's a lot of really interesting philosophical work happening in this period. So, the biologists who are the first to introduce these concepts of chance and methods of probability and methods of statistics into evolution, including at the very least, the kind of major cast of characters from my story. As you'll see in a second Darwin, Dalton, Weldon, you'll and and our agenda you'll an RA Fisher. They were really self conscious about their relationship with probabilistic and statistical reasoning they knew they were doing something that no one had ever done before. They knew they were doing something new and excited. And so in the process they actually developed really rich philosophies of science they thought very hard about how to justify what they were doing to their contemporaries. Those have not I think been been been explored in enough detail up to now at least not in a kind of single single narratives that was part of that was part of my goal. The other part of my goal is, and here's where I get to arguing against the giant red X from a few slides ago, what's also sometimes called the debate between geometry and mentalism. I think that the idea that that's the interesting thing that happens between 1890 and 1920 and biology is really mistaken. I think in fact if you get into the details here if you look at the practitioners, the practitioners work. If you get a story of continuity. There's a lot more sort of commonality going on here than a kind of a big, big angry fight narrative would lead one to believe at least with respect to these questions of chance and probability and stats maybe there are other ways to drive this. I didn't write six biographies obviously there's there's more to be said about all of these figures that I'm going to say, but I still think there's, there's a real, there's a real continuity story here. So, again, I make this case with 180 pages of detailed historical narrative. So what I'm going to do now is try to give you enough highlights in 30 minutes. But what your appetite to convince you that those two theses aren't not that they're true because there's no way I can convince you that they're true in half an hour, but to convince you that I wasn't a stupid idea to try to write this book and maybe it wouldn't be a stupid idea to try to read this book. So that's, that's the goal. If one of these figures in particular I should say because I actually I have bonus slides. So if one of these figures in particular interests you, and you want to know a little bit more about like wait, why would he say that about that I have, I can say a lot more in the q&a so don't hesitate to like push, even if you want pretty pretty aggressively on. I'm not sure about your reading of Dalton fine like we can, we can absolutely talk about that. So we begin with the man himself, the myth, the legend, Charles Darwin. Darwin is interesting in this context, I think, other than his sort of intrinsic interest and the fact that he documented his life so well that he gives a lot of material to historians and philosophers who want to know more about it. He's interesting in this context. I think largely because he's not very systematic about what he has to say about chance and the various assorted concepts surrounding chance. He never does anything that looks like formal statistical method. Andre area would have just would disagree with me here I could say more about that in the q&a but I don't think he ever does anything that looks like formal statistics. He deploys a number of notions of chance though in a variety of complex and interesting ways he spends a lot of time thinking about a sense of chance that we might now call accident in the sense that it's something that's not designed. There's a famous passage that occurs in the variation where he talks about what would happen if you built an arch out of rock that had just fallen off of a cliff. You would be designing something but you wouldn't want to say that somehow the pieces of rock had been designed to go into your arch that's crazy they're just geological artifacts right in that sense they're accidental. And so that makes them chancey in a certain kind of way. He definitely had a concept of the law of large numbers he talks sometimes for example about the idea that a bigger population would be more likely to be host to a rare variant like okay cool so he's got, he's got a probability notion in that kind of basic sense. He famously talks a lot and I've written elsewhere a bunch about this that natural selection isn't a guarantee it's a tendency. So natural selection doesn't say for certain that the fitter organisms will do well and the less fit organisms will do badly natural selection says well all else equal probably in general the fitter organisms will do better mostly. So he's very clear about about that and that has some that has some interesting philosophical implications that I that I try to tease out in the book. He's also very clear that we're ignorant of the precise causes of variations so variation is a black box for Darwin he talks sometimes about what he calls indefinite variation which for him basically means variation where we just don't have any idea. What it is that's bringing about that that that particular that particular variation and so there isn't, there's absolutely an ignorance aspect here that he that he underlines that he underlines a lot. That's a lot and he doesn't really connect these different notions, except I want to argue what I think is really poignant about the way he deploys chance is that he tries to keep it under lock and key. So every time he gives chance, what what seems like a big role in something. He has this real tendency to hasten to add that, but that is being watched over by natural selection. And for Darwin, despite the tendency aspect and that's where the philosophical story gets a little sticky. Natural selection is paradigmatically not chancey in the sense that it's guiding toward application sort of toward adaptation. It's sort of almost quasi rational process at work in nature it's a generator of order. And so in that sense, if every time that he sort of lets chance in he can say, ah well yeah but don't worry about it everything's fine. I'm still doing good 19th century science we're going to be okay, because all those uses of chance are sort of locked down by the influence the guiding influence of natural selection. A quick example I just like this quote because it's Darwin at work in his book on the orchids. He says here, you're at the flowers of orchids and they're strange and endless diversity of shape. They be compared with the great vertebrate class of fish are still more appropriately with tropical humongous insects, which seem to us in our ignorance as if modeled by the wildest Caprice right the ideas. If you didn't know about natural selection, you would think this was all random. But once you're on the inside and you realize that anytime you find one of these strange features which he's actually just been talking about through this book on the orchids. One of these strange features that seems like it's totally random. It's not. It's adaptive. It's probably adaptive for some reason or another. So that sets the stage for Francis Galton, another very interesting and very difficult character to to interpret. Galton reads Darwin in his kind of early middle age, and then proceeds to dedicate himself is Darwin's cousin by the way, dedicate himself to the study of heredity and especially of eugenics. He's a huge fan of the statistical and probabilistic work of the local pride here the Belgian astronomer Royal Adolf Ketley who had just developed some of the first treaties on social statistics in the mid 19th century. What makes Galton intellectually interesting for me and the way to kind of figure out what he's up to is to recognize, I think a kind of paradox at the heart of of Galton's work and Galton's impact on the generation of scholars that followed him. The first thing to say here is that Galton's arguments from a philosophical perspective are really not very good at all, like, shockingly not good. Bernard Norton here and his PhD thesis says he's talking about Galton's arguments surrounding natural ability Galton tries to measure genius in the English and finds of course that upper class white classic British men are all geniuses. Was as frequently with Galton very bad but the concept was powerful if vague and Swinburne who actually started out a little bit doing in history of biology which I didn't know before I wrote this book, writes that in here thinking about the inheritance of characters and the use of the law of ancestral heredity, his argument is quite extraordinarily bad. I think this is not exaggeration. Galton, he slapped dash with his arguments he very often has this really annoying habit of builds, almost all of a really good philosophical argument, and then he gets to the last step, and he either hand waves of the other hand waves past it, or he introduces some kind of physical to try to sort of say, Ah, you see, this must work because I can build a model of some physical object that demonstrates similar kinds of properties and you're like, Galton that's that's not an argument that's a that's a box. So, that's one half of the paradox. He makes an enormous splash and everyone thinks he's amazing. So, this is Carl Pearson and Pearson spends a lot of ink later on in his career criticizing Galton's bad statistics, but then Pearson still writes. No one who studied Galton's 1889 Magnum opus natural inheritance on its appearance, and that a receptive and sufficiently trained mathematical mind could deny its great suggestiveness, or be other than grateful for all the new ideas and possible problems which it provided the methods of natural inheritance may be antiquated now this is written in 1930 at Galtons death, but in the history of science it will be ever memorable as marking a new epic. So, people were into this, right, for all that we might critique it from the contemporary philosophical perspective and I think that that kind of paradox is a really interesting thing to try to unpack and and get to the other side of for me the key to squaring the circle is to focus on the open questions that Galton left behind. I think what makes Galton so exciting to these figures is that is sort of, they can continue those arguments that precisely the spot where Galton started to hand with. But in doing so, Galton pinpoints, if you want to build a statistical theory of evolution, which in combining his obsession with Kettle's social statistics, and his cousins theory of evolution by natural selection, Galton certainly wanted to do. If you want to do that, Galton finds a couple of points that you're going to have to pick up that you're going to have to engage with to build any such theory. More precisely, I think, first of these is he wants to spell out a theory of statistical evolution, natural selection taken statistically in terms of a theory of how do characters get from parents to offspring. So he's one of the first to struggle with the idea that there seems like there's a lot of characters that are passed on from parents to offspring but don't express themselves he calls them latent characters. Maybe we can figure out a way to think about these transmission patterns that can help us understand natural selection. The other thing that Galton is persistently bad at is recovering evolutionary dynamics. And if you know Kettle's work this may not be too surprising Kettle talks in some of his original works. One of the things that Kettle is always struck by is the idea that these normal distributions of characters and populations always look the same. Every year, the same number of people commit murder in Paris. This is one of his examples. The same number of people are poisoners. The number of people change the stories change, but the numbers remain the same. Galton eats up this statistical idea, and then he can't figure out how to make natural selection actually changing. And we see both of these characteristics in his classic example you probably have seen one of these at a local science museum or children's museum they're everywhere the Quinn conks the Galton machine the Galton box the bean machine, whatever you want to call it. It's really exciting, because if you put in a bunch of pellets I'm not sure if you can see my mouse pointer. If you put in a bunch of pellets at the top of the funnel here under figure seven on the left. You put in a bunch of pellets in the funnel. They run down through all these pins and low and behold they make a normal distribution at the bottom. And so Galton says, This is it. This is how we can show that this is what's happening when traits move between parents and offspring when populations build themselves in accordance with normal distributions. How does that work. He doesn't tell you but he has a machine. So this is exactly the kind of argument where now the credit the successors of golf they're going to say, Okay, wait, but now we need a theory that actually lets us understand how this really happens in nature. Same thing for evolutionary dynamics and everything that you might notice if you have a little bit of statistical training is this bean machine radically increases the variance of the distribution. The funnel here is really narrow and the normal curve down here at the bottom is really fat. How are you going to keep this appearance of things being static over time then, if the variance keeps going up. We'll now look at this box over here on the right hand side. I will just put a squeezy thing in the bottom. It'll bring everything. It'll bring everything together. I see I have a there's some connection problems I hope it's hope it's not on my end. Let me know and stop me if it is. Hmm. Oh, maybe it is me. Let me pause for just a moment. Okay, I'll keep rolling fingers crossed. Let me put a squeezy thing on the bottom. And then, oh, hey, magically, the distribution looks the same over time. Well, this is this is this is pretty arbitrary and ad hoc right he doesn't tell us at all. How is this supposed to represent biological reality, but that's an open problem. That's an open problem for his successors. And that takes us right to what's now come become known as the biometrical school so here on the on the left is Carl Pearson with Galton on the right. Here's WFR Weldon looking like an extra from a western movie. They are the two central figures of the school that comes that sort of comes in and tries to polish all this up who's really motivated by by Galton's moves here. Their research project starts by picking up on the second question on the on the question about evolutionary dynamics. And so, for the first time they go out and they make a bunch of measurements of here it's crabs in the wild I'll be talking for a couple of minutes. What they're going to argue here is you've got this non normal distribution Galton had no utilities for dealing with a non normal distribution Pearson is good enough at statistics to begin to develop them. That starts to give you the ability to think about this curve, the general population curve the curve you see on the top. As being composed of the two curves you see inside the big curve, which maybe makes you think that there's a speciation event going on here if the population is made up of sub populations. Perhaps they're being driven apart over time. And so we can start to maybe at least possibly construct a theory of natural selection on a statistical foundation. We can back this up with careful longitudinal studies. So here's from a from a letter Weldon talking about his colleague who then went out and measured some male crabs and Plymouth sound and discovered that there was really rapid change in a particular morphological character the same one that was being measured up above. So they then try to back this up with adaptationist causal hypotheses to try to understand what's going on in these populations so Weldon's enamored of the idea that it's probably has something to do with the fact that we're silting up Plymouth sound. All the ship traffic. They've built a breakwater, and the river is no longer flushing out effectively the silt that's accumulating in the bottom of the sound. The organisms are dry are dying off and so perhaps my favorite thing I found in the archives here's Weldon's diagram from his from his notebooks crab. Perhaps when water comes into these crabs at the point smart by the arrow. It's not being filtered well anymore and so they're dying because or they're being driven rather in the direction of improved improved filtering capacity. Now, that was their program up until the rediscovery of Mendel's results and here's, I could say I could talk for an hour about this photograph but essentially once Mendel's results are rediscovered at first they try to just sort of dismiss them like God this must be data artifacts we haven't seen anything that looks like this then we get enough examples that they say okay. What we need is a theory that can sometimes give you Mendel's results as a special case, and sometimes give you the kinds of normally distributed characters that we've seen in other examples as a different kind of as a more general case, if you will. They become progressively convinced that actually or Weldon becomes progressively convinced that there's a molecular story to tell here, he goes back now to the first open question that Galton had left behind. How can we tell this story of character transmission. In terms of the passing of little particulate characters from parents to offspring, but in such a way that we can interpret that statistically and Weldon writes here. Now, Galton's old idea is the machine that will work we just have to figure out how that's actually going to go. They become steadily convinced and talking with cellular biologists that it's got to be something on chromosomes of course they have been nothing of DNA that's that's not till that's not for for 50 more years. But they're convinced that there's something on the chromosomes that must be governing this transmission of characters from parents down to offspring. There's just one problem with this research and it's it's so there's actually I take it back there's two problems with this research. One of them is it Weldon dies at 36 of pneumonia after overworking himself essentially to death lesson for all early career academics in the chat myself included. dies of dies of dies of pneumonia. Now, that's bad. The other thing that happens is they don't have the mathematical tools they need to actually pick this stuff up. Don't really pay attention to this equation and long story short what I'm trying to show you here is the 19th century methods for trying to parse hyper geometric distributions which is what this turns into. They can do the it's technically it's simply too complex it's theoretically from math from a statistical mathematical perspective, it's just too difficult. They don't have they don't have the conceptual or technical tools that they need. So this project in the end is a failure. Weldon's project to try to derive these connections is a failure, but, and I think this is the point. So the first time right, this is all the parts of the shift that I was trying to look for right tonight. This is a statistical theory of evolution that lets us understand the action of natural selection at the population level. They're trying to harmonize it with Mendelian trans transmission and you have this as early as 1904 1905. So historical curiosity, duly noted. There's just one problem here. And that is, if I've argued that this project fails, then I owe you a story of continuity. That is to say, why think that this matters for anything later in the history of the biological sciences. How can I resist this idea that I mentioned from the classic story at the beginning that really it's Fisher and Wright sifting through the wreckage of this period and picking out the two or three good ideas that matters for contemporary biology it's not this fancy story that I just spent that I just spent 10 minutes trying to trying to make sense. The first line should say three in the book I offer three stories of intellectual continuity this is an argument that really that really motivates me. I'm only going to show you one of them tonight I only have that's all I have time for this morning. The first which I'm not going to talk about is there are actually a number of well known works that sort of take one piece of this larger perspective this larger program and advance it if you will in isolation. Without advancing the whole thing at once. There's a peculiar case of George ad new yule about whom I can say more in the q amp a sort of synthetic figure before his time, the very interesting, very interesting case. What I want to spend a brief moment on I don't have the time to really show you this argument in detail but is a is a case coming from the textbooks. What happens if you look at the textbooks of evolution that were published between 1905 and 1920. Do you find evidence of this bloody warfare that supposedly happened evidence of the failure of the biometricians to make a difference. The victory of the early geneticists and and the sort of black hole prior to the development of the modern synthesis. And what I want to argue is no you don't wrong direction. I picked up three textbooks I could I could justify this choice more in the q amp a if people are interested but I picked up three textbooks locks. 1902 recent progress in the study of variation heredity and evolution it's reprinted in six editions over this time period lock also dies in the middle of this time period of overwork. J Arthur Thompson's heredity another another general text and yes good which is a little hard to read but the evolution of living organisms. What do you find in those textbooks but what you find in those textbooks is careful cautious reasonable presentations of both biometry and mentalism both the statistical side and the genetic side. There's not any indication of a hefty sort of all encompassing conflict between the both of them what you tend to see is a real desire for unification, a real idea that exactly the kind of theory that I already mentioned a sort of unifying, statistically grounded but sophisticated and careful understanding of natural selection. That's what biology should be trying to do. That should be our target right now. That's exactly what what you find in in these textbooks and so that's not that's not I think what you would expect according to the classic history I think there's a real story of of a long standing continuity here. How am I going to end the story. There's many ways that I could do this. I picked as it turns out are a fisher. I can justify that briefly one fisher is just really, really interesting another very difficult historical figure to try to understand for lots of reasons some of which I'll talk about real quick. Also, Fisher is undeniably a part of the tradition that leads to contemporary biology so if I can say when with some degree of convincing this, that my continuity story can get us to Fisher, then my continuity story can get us to say in some way or another, and I can hand off to historians of the following few decades, again to make that to make that story more compellingly than I would. So fishers yeah weird and complicated. Yeah, it's a it is a fantastic beard, fishers and fishers. Philosophical commitments are super wide ranging. Maybe unstable actually. I like that as a, it's one of the conclusions that David David Depew and Bruce Weber, hi David made in in their book was that like this stuff doesn't hold together really in the end and I think there's really something to that. At the very least of the four that I'm going to pull on for the moment, deeply committed eugenicist one of the only people I think to have plausibly lived his life at accordance with eugenics he produced children like a eugenicist very weird in that sense unusual figure. Anglican Christianity so it's for him very much grounded in a in a in a Christian ethic. He says this view of indeterministic causation which if you haven't read it and you're a philosopher of science and this sounds cool. He has a paper in volume one issue one of philosophy of science the journal 1934. One per interesting strong recommend. And he also is one of the most important figures in the entire history of statistics he has a very refined statistical method, most importantly for the natural selection case. He makes this distinction between the statistics, you take on a sample and the parameters of the hypothetical population that a statistic is intended to estimate and it's Fisher who really introduces that for the first time. Big, that's really important at that this at this period. It's really important to help and help you understand what's happening in the biological case. But he's trained in exactly this very textbook tradition. If you go find as Anthony Edwards did. There's a copy of locks textbook in the guys college Cambridge library, you will find that it's graph legends are annotated in Fisher's weird handwriting. He was absolutely reading exactly these textbooks. We know because he worked with and then got in a fight with Carl Pearson he was super familiar with the biomedical literature. All of this kind of unifying proto synthetic literature that I've that I've been saying is the kind of conduit for these ideas of a nuanced statistical theory of natural selection into the early days of the modern synthesis. And so that, for me that's a good place to put a to put a pin in in the historical narrative because by the time we get to Fisher's Genetical Theory of Natural Selection another very interesting book from 1930. We're in the mainstream of texts that are still important for contemporary contemporary evolutionary theory for better and worse of course GTNS if you haven't read it is a very odd book. And I could say more about that in a Q&A if if people are interested but we have a thoroughly statistical theory of evolution here that's a decent approximation to contemporary population genetics it looks a lot like we would expect a modern theory of evolution to look. So let me sum up briefly. I haven't been able of course to give you to give you the full story today there is a level of detail that I will that I will not be able to to reproduce. You know where to find it. But I hope I've at least tempted you with with the broad outlines I think I hope I've been able to make it clear. There's really rich, deep, exciting philosophical content in this collection of authors surrounding exactly this question this worry about how we're going to introduce theoretical concepts of chance and the kinds of methods. There are also statistical probabilistic methods that we would use to make a better sense of those of those concepts in an empirical case. They're also thinking really hard about why they would do this. The subtitle of the book, in fact comes from a critique that Weldon once received. I have my suspicions that it was from William Bateson. In a in a large address to the British British Academy once said that someone that accused him that accused to him that statistical biology was just a way of saying with a pompous parade of arithmetic something that we all already knew all along. If you're confronted with that kind of attack, you have to spend some time thinking very clearly about why you would persist in the face of that kind of pressure, and they do, they really do. And they're also, I think, this lovely is there's this lovely story of intellectual continuity here among these very weird and very complex and very difficult figures that I think can really illuminate. Historiographically to put on my more HPSE hat for a second historiographically the shift from a sort of open warfare frame to a continuous and almost tempted to say normal science although that's probably overkill kind of frame. I think tells us a lot. I think it's really illuminating and really helpful to understand this period. So that's it for me. The book has a website at the books website, especially if you teach biology to secondary or bachelor students you'll find a series of six lesson plans to teach history of biology to to your students in English and in French. There's all kinds of resources there. You know where to find me. If you are, if you are interested please do not hesitate to to get in touch and I'm super happy to talk with you more about it now. So, please, thanks so much. Thank you so much Charles. So as I said at the top, I will be moderating the questions. So if you could indicate that you have a question using the raise your hand reaction. And I believe I've changed the security settings so you now should be able to unmute yourself and let me on your video if you let me turn off the screen share so that that gets out of everyone's way until I need it unless I need it again. And let's start off with questions from any undergraduate or graduate students in the audience today. Any questions from students. Okay, in that case, I guess we will open the questions up in general. Is that a question from David DePu. It is. Okay. I'm just gonna read to you Leslie and appreciation to easy way to see you I don't have to go to Belgium, play it's a real pleasure it's been a while. Yeah, I hope you're well. I'm fine. So, Well, sort of fine. Fine as anybody else. I mean, I found that illuminating and going back to those source books in that period. Because the whole story that's normally told is basically the story of genetics. And that story in turn is often told from the perspective of the development of molecular genetics which is like way down the road. So the period you're talking about what actually happened was that the development of statistical biology is really this, the main story, right. But I, so I noticed. Two things is that you'd I, the way I told the story which is not based on any detailed reading like yours. So the idea is that got stuck on regression, which you didn't talk about too much. So the idea is that if, if you lose half of your heritability at each generation, pretty natural selection could not become an innovative force, unless it overcame that barrier. I just thought you might say more about that but the second part of it is that you will the way the story is told in secondary books like a proline, which by the way is a really great book. Origins of statistical population genetics. Is that he was a mathematician, and they, they asked him what would happen if you had the Mendelian characteristics. So you have those laws basically as you go from generation to generation. And by using the quadratic equation he proved that you don't have any automatic built in tendency to regression, you have a distribution of dominant and recessive and heterozygic combinations that remains the same from generation to generation so that the chance of natural selection overcoming it it doesn't have to overcome that bigger barrier it just simply has to introduce a force that's strong enough to basically overcome the equilibrium distribution. And I just wondered if you'd say more about that. Yeah. Cool, good, obviously to great to great questions. So, yeah, so so go on regression yeah. Absolutely. That is probably the place where and I've been forced to clarify my thought a little bit more than that in actually have a paper on reversion that I'm actually coming out any day now. It had to sort of fell out of the book. It didn't it didn't make it into the book. So it'll be out in studies in history and philosophy of science and the next in the next probably couple weeks actually in preprint. What I think is interesting about about Galton on regression is that I'm not ever sure that Galton sees clearly what Pearson will eventually see, which is that regression as a statistical idea, and reversion as a biological phenomenon as a statistical idea that you know sometimes if you have a fancy pigeon eventually it looks like a not fancy pigeon. I'm not sure that Galton really saw clearly that those could come apart. Whereas, you know, Pearson very very obviously is the first but I think the most the most the loudest if you will to say, Yeah, but you can compute regression of offspring on parents and you can compute regression of parents on offspring you can't be talking about directly immediately an inference to some kind of hereditary hereditary process that falls apart immediately, right. And I, I'm not sure that Dalton saw that at all so I mean I don't want to deny that that's that that's important. And I've, I would have written I would have written a bit about that in the book differently than I than I now than I did, then I did when I wrote that chapter for sure. I think on you'll see yeah super interesting figure I like I like G on the you a lot. The thing that one so I have a lot of hypotheses about you but I'll advance kind of the weirdest and coolest one because it's it's it's kind of new I think. I think one of the problems with you all is that both Pearson and William Castle misread his statistics pretty early on in like oh three. Yule is trying to do something that nobody really quite realizes what it is that you will is trying to do. And that that kind of hamstrings and people don't interpret him in the right in the right kind of way after after he gets this he sort of gets tagged with this. Oh he doesn't understand doesn't really understand the law of ancestral heredity doesn't really understand genetics either you kind of gets tagged with that early on. And it gives people a reason to stop paying attention to the paper. And so I think there is a weird. I tried to give an argument I've been emailing with a bio statistician at Columbia about whether or not I succeeded at giving this argument maybe I didn't. But I've been trying to argue that actually no there's a way to kind of salvage what he's doing if you think about it in a slightly different way, which might explain why people weren't weren't really taking him very seriously at the time. I have a lot more to say than that but hopefully we'll have a chance to go into more depth soon. Thanks. Alison. Hey, thanks so much for that. So, I'm wondering if you can help like explain how this model of warfare between the biomedical and genetic views. I guess why that's why that was a dominant narrative in contrast to the continuity picture that that you've proposed so like I take you to cast this as something of a false conflict that was, you know, developed by historians but why would that conflict narrative have eclipsed the continuities that you've been tracking do you have can you say anything about that or do you talk about in the book. No I can do that quickly and that actually that's really good I should I should clarify and and let me make let me make a note that that I shouldn't I give this talk again and I hope I will I shouldn't let you have had that impression to be clear. The conflict is not a false one. These guys hate each other's guts and want each other to die. It is brutal. At one point, at one point, Bateson publishes a book that's like a new not very good translation of Mendel but it's mostly an excuse for him to write like 50 pages about why WFR Weldon sucks at biology. Okay. Weldon, Weldon writes to Pearson at one point and refers to their real to pierce to Weldon and Bateson's relation or fight as quote, poultry and dirty beyond measure. Well, so this is why I mean you kind of gestured to the right that there were these like very sort of public and well known fights and conflict that happened and so I was wondering whether we could make a distinction between sort of the intellectual continuities that that you're tracking, compared to what historian, the other historians might be interested in considering the socio political context in which they were engaging right where those conflicts would take the forefront. Yeah, no I mean I think I think I think it's how to put it I think the other hypothesis that I have for this this is probably the one that holds more water, because I do go into this a little bit at the start of chapter five. I think if you pay too much attention to in particular if you pay too much attention to Carl Pearson and William Bateson, you actually do get this idea. This idea comes through in their writings. So I think there's a great man history problem here. Pearson for his part actually does pretty much say, I'm a quit doing evolution because I'm tired of fighting with these people he practically says as much right he stops going to conferences. He stops writing papers on evolutionary theory. Bateson basically starts writing in textbooks like we won and we don't have to talk about those people anymore because we won the social fight. So if you read them, but you don't look and you don't look at the textbooks, I think that's where you get the I think that's where you get the bad impression. Okay, cool. Thank you so much for that this is great. Thank you. I'm sorry if I butcher the Irish pronunciation, I believe it's new look. Yeah, totally spot on and totally cool if you butcher it's kind of fun to figure out what people say. And this was awesome I have like a gazillion questions, but I won't talk all the time by asking you, but I don't want question for you and it's really but I know that it's not going to have a simple answer is, and you talk about the terms chance and population. And I was curious what your historical after is defined but also you as the person analyzing it, because that was kind of as I was going through it I was like, What does he mean by population it's still sort of so for grabs so if you could say a little bit about what your actors mean and certainly what you mean as an analytical tool of chance and population. Thank you so much this was so good. That's yeah good. You don't need me to tell you it was a good question. It's a good question. What can I say that won't that again what can I say that won't take an hour. Population first population. You're right, obviously in flux during this period. I am not sure that I'm not sure that Galt has a clear idea. When Galton talks about having a clear idea what he seems to have in mind is something very concrete and real life so he talks about you know, statistics means you could take the actual living inhabitants of England and sort them by height and get a bell curve, like the humans the physical human beings you could put them in a line. Pearson seems to have Pearson and Weldon seem to have a fairly similar kind of idea. I actually I actually think I've I have I have largely. I've largely picked up picked up the analysis I think I think Marty Morrison is exactly right in her. She has a wonderful paper on this, where she says it's not till Fisher and one of the things that's big about the Pearson Fisher disagreement is that Pearson has this kind of actualist present this understanding of the population. And it's only Fisher who can talk about populations that aren't really there for the first time about a population as an object of scientific modeling as an abstract construction that evolution is going to apply to. I think she's spot on. I think she's spot on with that. I'll stop population there now before I fall in a hole. Chance is harder. So largely what I am what I am looking at is a sort of mean the five second answer to this question is. Part of the project of the book to try to demonstrate all the manifold things that these different authors had in mind when they decided to deploy those kind of that that notion. But the, the, the, for me as an analytic tool what I'm looking for are probably the quickest way to yeah this is the quickest way to say this. Darwin's hesitation to deploy or to let chance out from under the blanket of natural selection has to do with a deep and abiding commitment to a kind of broad Newtonian methodology that 19th century science was supposed to be about deterministic laws that would guarantee to you what would happen to populations and so maybe selection can give you that if it's if it clamps the vice down tight enough. It can give you that. And so there's this shift from that to and and actually here I think I think David's accounts really good. Letting chance be an active ingredient in your in your scientific theories letting anything that's not absolutely hard Newtonian predetermined play a real role in your scientific explanation I mean we all. We all took the hat to hacking here I think hacking is really wrong about Galton but that's a separate concern hacking hacking gives all the love to Galton here and I think that's entirely wrong. I think hacking in general this idea that what matters is will let chance be up first class citizen in our scientific explanations. That's the move I'm looking for as hard as it is to pin and to pin and define intellectually so that's what I'll say for now. Okay, I, there was a hand from David Ardell. Hi, yeah, I did have my hand raised. So, congratulations on your book and thank you for this wonderful talk which I really enjoyed. And I'm looking forward to, you know, reading your book and and and also thanks for mentioning these resources for the this history for students, because I do teach evolution and I'll mention that I have my, my wife here is also a professor of evolution she's teaching evolution of semester. So we, you know, so I, I have a question and I have to quick reflections I'll try not to take too much time to I tried to distill the reflections into this question. So the question is, I'm looking forward to learning more in your book about, you know, specifically impacts on the process of review for for evolutionary biologists so you mentioned the textbook case. And I mean, and the reason I'm asking about this, and the impact of the personal, you know, animosity between these schools, and how that affected other, you know, third parties in that period. Because, because I imagine that there were impacts. At the same time, I also saw my two quick reflections are really by your, your argument of course that the continuity of ideas and more importantly, that of science as a population process with variation and diversity. You know, as opposed to the that that we would tend to simplify the telling of the story by personifying these ideas in certain people and kind of oversimplifying it as a like the warfare of the Greek gods, you know, and it's easy to go that way with, especially when you're talking about someone like Fisher. And so the other reflection which goes. I guess a little counter to the argument is ironically, of course, Fisher is famously combative about, you know, the next stage of history of science so in the causal role of smoking tobacco with cancer and the dominance of the randomized control trial. And in fact we're still today living with this stultifying impact of frequentist statistics on education and research. So we're still just generations later still facing, you know, the shadow of this personality and so that's my, you know, that's those are my reflections thanks a lot for your talk and very much and to this great group of listeners I've just enjoyed being part of this event. Thank you. Thanks so much I really I really appreciate I really appreciate both of those let me let me let me chip in let me let me chip in my two cents on the latter one. Yeah, absolutely. How to put this, another nice thing about stopping my story in 1930 is that it meant that I could stop trying to understand Fisher in 1930. Because he is so difficult I spent probably six months on the first whatever that would be, you know, 25 years of Fisher's career. I cannot imagine what it would take to, I mean, really actually get into those motivations of what happens a little bit later. So I don't I definitely don't want to deny that that there's this double edged sword here that these big personalities have these have these kinds of these kinds of long standing these kinds of long standing effects and and you know he's he's less well known because the shadows not quite as long but Carl Pearson has exactly the same, you know, exactly the same kind of impact so I mean I'm these are, these are difficult people to say the least and distasteful all as well that's the other except except. Well, okay. Charles Darwin seems like he was by the standards of the date, fairly decent. This is a tough period to be a historian to do history and I mean this is hard but but no you're exactly right you're exactly right thanks for that. Ben. Yeah, hi Charles thanks for that really interesting talk. This is what is probably an annoying question to ask about a figure who's not in your talk at all, despite all the names that you mentioned. And I'm curious if you've read or have any thoughts about what Charles Sanders purse has to say about chance. There was a conversation that a previous questioner asked and then there's some some discussion in the chat about this as well. And yeah he was basically talking about the ontology of chance and kind of giving it saying that it's that the real force and that you know laws of nature themselves evolved out of chance. I'm just curious if you had any thoughts about that position. So, I'm going to give you a I'm going to give you a glib answer and then I'm going to totally walk it back the glib answer is shockingly enough. He's nowhere in the transmission chain. And so, you know in in in trying to tell this this this really grounded continuous story. I would have loved to have wedged him in to wedged him in and I didn't find anybody talking about. Let's set back some. I am really interested, although I haven't yet had the chance to do it. In doing more to extend this story stateside. And this is a very English story right now. I mean I also want to extend it Belgium side to Belgium side and France side now that I have the language. I didn't when I started writing the book. So, that I think the closest I get to the states is a couple of those figures when I mentioned that there was this there was this little bubble of work and the odds and teams of people sort of taking little parts of this and running with it over time. Some of those are Americans. And I really am interested to look at at that story better. Obviously, well, really to see if I can do anything that's not just a bad version of Trevor pierces awesome stuff that he's already done on this pragmatism's evolution. You Chicago press 2019 or 18 or 19. Go buy it. Trevor's Trevor's awesome. Trevor nailed the pragmatism connection. But I, but I don't know to what extent he picked up the chance angle. Right. So I, I, it is on my to do list. But I do not have anything intellectually satisfying to say about it in the meanwhile. No problem. Thank you. Since we don't have any hands currently. I like Allison to ask her question from the chat. Sure. Um, so well I was wondering whether chance was now I just have to look at what I wrote. Okay, yeah, what was chance black box as something of a, an occult quality similar to what Coon said about gravity for the Newtonians because I remember, you know, reading and he was talking about how it was a concern at the start, but that eventually so over time the Newtonians just kind of accepted gravity as this innate tendency. And like ignoring the earlier fear of scholastic science and so do you think, like, could we say, I mean I put maybe did own this case right because the way that you express sort of Darwin's fear of this and then is there like an increasing approach over time, or an ignoring of it yeah like what do you have to say about that. Yeah, no that's really great so I think it's close to that I think what I would want to say. Although I should okay I'm going to I'm going to I'm going to give you what is sort of my my my personal party line on this and then I'm going to and then I'm going to caveat it immediately. What was said before in print for that matter is that this isn't, it's almost like that, but that that has a metaphysical cast to it. And I think it's methodological rather than metaphysical. If you let if you're the sort of philosopher who let's do who let yourself make that distinction I know some people would just toss that out the window anyway but because I think, I think it's very much about the mold of what it meant to be doing good 19th century British natural science. And that what that and sort of what that looked like if you are a good student of your Herschel and your Yule and your mill it in the in the time period what that meant was. We find crisp causal laws here, this is what we do. We don't find fuzzy, fuzzy, fuzzy, fuzzy, fuzzy vague stuff fuel not I am, I am at the university that houses the Husserl archives but that is not my that's outside my remit. I think it was just it just it just it just was outside the realm of what he would have been willing to call scientific. I might even I might even I might go so far as to say and it took a while for that to kind of crack apart. But especially if they're looking for like mechanical explanations right because that was the concern with the occult qualities as far as I take it is that there was no kind of like mechanical explanation or nature that would fit it well within the frameworks and so it seems like by black boxing. You know the wild Caprice right this, it does sort of the same thing it allows it to like have a placeholder and function but like don't worry because it's, and we can just kind of ignore that and has this kind of background. What you get over the 19th that's really interesting is you lose the hard mechanical but you keep the methodology because they want to make room for the wave theory of light. Yeah, and they don't have a mechanism for it. Um, but that was that's the I think that's the I think that's the I think your your head's in exactly the right place I think that's the that's the move right it's the it's the heritage of mechano Newtonianism that just take just takes us off the table for a while. Thank you. Carolyn. Thank you. So, I was really interested in hearing you talk a little bit more about your preference for continuity over revolution in general and if that's a general preference and because I'm not familiar with the literature what maybe it's not just you personally I think it's a trend in philosophy of science that I'm unaware of the one thing that I could see coming out of your talk on this was that in the classic story, it seems like a lot of, a lot of credit is given to Fisher, you said that you know he kind of picks out from the ashes and then at the end of your talk you said that Fisher had actually read these these pieces that do some of that work so seems like from that example that part of the reason you might favor continuity over revolutionist so you don't incorrectly put all the credit into the hands of like one seemingly crazy person. Is that what is that what you want to do you want to like socialize science or show show a more distributed credit or are there other reasons to. I'm not sure I've ever asked myself this before so I'm going to like freestyle for a second in in in my answer I don't, I don't have a I don't have a canned I don't have a canned answer ready for you. This is a really cool question. I feel like so on the one hand yes I mean I do think there's something to. I think this is this is in some sense playing into a broader trend of it seems difficult to put it. Once we begin caring more about practice, which is assuredly a trend a general trend in the philosophy of science over the last 30 years. Once we start caring more about practice, it seems difficult to sustain anything that looks purely like a great man narrative right and so if I if I think as I do in this case that the the warfare narrative is a legacy of a great man narrative then there is a sense in which that's those those aspects are playing in are playing into each other I think. I do also think that you're probably not wrong that there's some kind of personal preference at work here to I mean I am a kind of. I'm a card carrying HPS guy at the very least and I'm and I'm and I'm pretty on the on the spectrum I'm I'm pretty out there in terms of, you know, I think that the I think that the the the social construction and meaning making type stuff that's going on in this is really, really important. And we can't we can't jump over those those parts in our stories and so you're probably right as well that there's just a little bit of, like, I'm kind of wired to find that in here I think probably. But thanks. Yeah, I've never really tried to think about that before that's a really great question. Oh, you're muted. Yeah, this is just a comment and hope that Charles and other people might say something about it that is that you kind of black box when you forget talking but only maybe for the talk, sort of the nature of these. So if, if I have, I want to talk here about this was triggered off by the remark about purse. So, I think that in Charles Darwin today's what you mentioned, and all the other methodologists that they really did have an ignorance interpretation of chance because the world had to be a certain way. And that if one law failed they all failed. And I also take the point now that I've never seen clearly before that is that in order to get around that without changing their metaphysics of the word. There's a kind of positivist phenomenalism that develops as the sort of matrix in which all of this stuff occurs. And that results in everything from statistical mechanics to the neo Darwinism, let alone social science. Okay. But about purse, I actually think, and I could be wrong I mean I've studied his texts, a lot of them. And they are as confusing as anybody else but I actually think that he has a pro what's called the propensity interpretation of chance that is chance is actually built into the universe. The nature of the world itself is chancey. And that he develops, by the way he, and maybe one or two other people are the only people in America at that time that really understood the new statistical mechanics. And he also saw very quickly that this was going to cause a big problem for philosophy because philosophy had built into itself, since Kant, a kind of way in which Newtonian mechanics becomes an a priori truth. And he, so he is simultaneously revising Kant and revising Newton. And he so he thinks of laws as the leading edge of a wave in the universe that is getting harder and harder. And that the things that we call fixed laws are like the backwash of this open front. Right. I mean it's an extraordinary vision. And I just want, I think that there are people now, Karl Popper was one of them who hold these propensity interpretations of reality. Other people do too. I think that might actually be a kind of a wave of the future, but I just want to, I think that's a good reason why he's not in the story. I don't think anybody got this. That's, that's always a way that one can be too far ahead of one's time. I think that's, I think that's absolutely possible. Also talk about weird guys. Yeah, yeah. I had a professor in graduate school relate to me an experience of trying to deal with the purse archive once it sounds like it's not a whole lot of fun. Bit of a mess. Anyway, Yeah, that's that's that spot on and there's there are the now I really do just have to say there's threads of that all the way through the book and it's and it winds up coming it winds up becoming complex enough that I can't even I can't even do them quickly justice here, but you're exactly right that that's, that's got to be one of the things that's moving around over the course of this period for sure. And it is. Yeah. Jeff. Yeah, hi. Thanks for the talk was really interesting. I hope you don't mind since we're near the end, I was going to zoom out to the meta disciplinary level. And this question is meant in absolutely the friendliest manner and not boundary policing I just realized as the talk was unfolding I don't know, have a lot of experience with history and philosophy of science. I was kind of waiting for you know here's the argument the philosophical argument. And then part of me is thinking well this is, this is like scientifically informed philosophy of science informed history this could have been done in a history department look and I'm very interdisciplinary I get this kind of thing all the time what is this philosophy is a cognitive science. So I mean this is purely like, could you give us a little like how does, how do things often go what's the game. You know it's, it's, it seems a little bit like especially the last few threads like history of philosophy is a thing right and so why shouldn't history of science and philosophy of science be a thing that's carried out in roughly the same way. So I don't know if you could just talk a little bit about framing this kind of inquiry for me. Absolutely no that's a that's a great that's a great question because we are a progressively rarer breed I think unfortunately there was. There was a time when and it was I think largely between the kind of 60s and 80s that integrating the history and the philosophy of science was the was the wave of the future. And so there were loads of graduate programs of which then and I went to one of the surviving their remain at Indiana Notre Dame Cambridge sort of it perduance and Pittsburgh. Maybe a couple others, not that many. Yes, cargo, yeah, yeah, yeah, yeah, yeah, this is kind of a kind of a wild card but yeah yeah. Not that many there were many more programs that really take as a card carrying move, trying to integrate this and what I'll say is, how to put it, I mean I, there's a lot in there not to like, but I, I kind of. I think you could take pretty seriously the first paragraph of Coons structure scientific revolutions, and right at the very beginning of the book he says something to the effect of. If we had a serious and careful vision of the history of science there are a lot of things in the philosophy of science that would not be the same. And there's parts where that's over over drawn but I mean I think I think there's I think there's really something to that and so part of what and now I don't have the chance to do this. How to put it, I don't have a chance to do this work here because I have to get the history right. And so you're right this is this book is this is the most historical thing I've ever written I might say I'm a bit scared by that fact, frankly, because I have an HBS degree but I consider myself a philosopher not a historian science. But I think telling the story of these sophisticated and interesting philosophies of science that are at work in this period has to have does have I'm not I mean I'm writing you a promissory note right now, but has real impact for how we think about the relationship between these still extant chancey and probabilistic theories in the biological world evolutionary theory. Sorry yes HPS does stand for history and philosophy of science yes my apologies. Does does teach us something very interesting and very important about how we should understand the relationship between these statistically phrased biological theories in the natural world. I think that's, I think that's really important, I think. I think they are trying out and here I can I'm actually kind of I'm borrowing the the interpretive frame of Hasak Chang I think there's a sense in which sometimes we find that these historical figures worked out really interesting ideas for philosophical, or even scientific approaches to questions that we lost become for good reasons when their sciences stock being empirically productive or fruitful, but that don't deserve to be intellectually lost that really can cast interesting light on how a philosopher of science might think about, you know the theory world relationship in in natural selection, for example, and so actually, you know I've also done a load of work on kind of contemporary causal foundations of evolutionary theory work and that's been really informed, I think, by the engagement that I've had with these with these historical figures so it's a methodology that's really worked out, worked well for me I learned a lot when I go when I go back to these texts. And I think philosophy of science contemporary philosophy of science can learn a lot. When we go when we go back to these texts. Not a knock down argument that leaves look I say at least a lot of kind of pro whatever future promissory notes. In the pipeline, but I but I think I think there's something to it, at least I hope there's something to it. It was very helpful. Thanks. Thanks very much. I think that short manifesto and apology for integrated HPS is a fantastic note for us and on today. So please join me once again in virtually thanking Charles Pence for joining us today. Thank you guys so much this was this was super fun and the questions were fantastic I extremely appreciated it was phenomenal. Thank you.