 Hello. Welcome back to history and philosophy of science. I'm Matt Brown, and today we're going to talk about the chemical revolution. I'm just going to give you a pretty short and sweet introduction to the topic because I think our pieces that we read by Paul Hoeningen-Huna and Hasak Chang for today are relatively straightforward. So what I'm going to do is I'm going to talk just a little bit about the background of the chemical revolution. I'm going to talk a little bit about our two authors and just give you an introductory framing for their essays. So first, the chemical revolution. So the chemical revolution takes place in the later part of the 18th century. It is a sort of conflict or it features the replacement of the older Flegistan theory or Flegistan theory with something like what looks like modern chemistry theory due to Lavoisier, the French chemist. So the Flegistan theory, it has its basis in 17th and 18th century chemical research and practice, although it also has roots in ancient traditions. It's a long state like the geocentric or Ptolemaic model of the universe. It has its ancient roots. The Flegistan theory is a family of theories of chemical change and it depends on basically the combination and separation of different elements and what are called principles. This notion of principles is a little hard to understand from a modern point of view, but in effect, a principle is something that when combined with a relatively inert element generates some kind of change or active property. So principles are involved in changes like combustion, the creation of things like acids and so on. The Flegistan theory is notable because it unified many types of chemical change under one form of explanation. So apparently diverse kinds of things, combustion of organic materials like the burning of wood, the combustion of inorganic materials like sulfur, as well as what was called calcinization, which is a transformation from metal to a kind of ore and back again, were all considered the same kind of process. And we still consider them to be the same kind of process today. That's something that was preserved by the modern theory. Now, Lovacier's main innovation was to replace the notion of Flegistan with a principle he called oxygen. Oxygen literally meaning acid generator. He thought it was also involved in the creation of acidic materials, acidic chemicals. But the Flegistan theory explained combustion and calcinization as a matter of Flegistan leaving the material. And Lovacier saw it as a matter of oxygen being gained by the material. That's the main explanatory difference. And as we know later, although Lovacier thought of oxygen as this principle, it would come to be thought of as an element like any other element. Now, there are various explanations in the historiography for why the field of chemistry switched from the Flegistan theory to the modern sort of paradigm. One of them has to do with more refined quantitative measurements of the weights of materials in chemical change and a greater emphasis on the quantitative relationships of weights of materials. So that was a major part of it. But there's obviously a lot of complexities to the process and different historians explain it in different ways. The first article that you read for today is by Paul Honiganguna. Honiganguna was a colleague and then a friend of both Kuhn and Fireabend. He wrote a systematic book on Kuhn's philosophy that is really important as an interpretation of Kuhn, understands Kuhn not as a kind of irrationalist or proto-sociologist, but as an important philosophical thinker. Honiganguna also worked at Zurich with Fireabend and he wrote on themes like incommensurability that were of interest to both. He's obviously younger, he was younger than them, but to sort of carry on that mode of thought. Honiganguna gives a very standard Kuhnian interpretation of the chemical revolution in this paper. In some sense actually you might say for Honiganguna the chemical revolution is the paradigm or meta-paradigm of the scientific revolution. So one of the things that you might take away from Honiganguna's piece is not only how we understand the chemical revolution as a paradigm shift, but also how Kuhn's own sort of study of the chemical revolution contributed to his whole overall theory of paradigms and revolutions. Hasik Chang's take on the question is as much more Fireabendian. So Chang considers himself a pluralist. Chang is really interested in how complex the construction of measurements is. In a lot of work he kind of unpacks, for example in one of his books he unpacks how we came up with the concept of temperature based on more intuitive notions of heat and cold and how we figured out how to measure it in a reliable way. And he spends a lot of time investigating the kind of mutual dependence between ontology, theory, measuring tools and techniques, and what we consider to be the observational evidence. Chang's also one of the best living thinkers on the integration of history and philosophy of science together on why and how history and philosophy in particular need to work together to critically understand science. So despite sort of what we've read from Kuhn and Fireabend and other ideas about why history and philosophy of science depend on one another, a lot of historians and philosophers of science today think of themselves as doing separate things. The Chang is a big advocate on their integration of the two. Now in his piece Chang shows, among other things, that Lavoisier's theory was a lot worse than we think of it as being today. And that the Phlogiston theory actually had a lot going for it that was lost when the theory was rejected. A lot of modern concepts from chemistry that were in at least a kind of nascent or early form in the Phlogiston theory that basically had to be rediscovered many decades or even over a century later. And Chang thinks that maybe within the science a better approach might have been a pluralism of chemical theories. And within the historiography of science, a plurality of approaches to how we think about chemistry would also be helpful. The paper I had you read today, one of the reasons I included it, among the many different things that Chang has written about the chemical revolution, is that it has this really interesting reflection on the historiography of science. That is, he's thinking at a meta level about how we tell the history of science, how we construct and narrate the history of science. He argues actually that it's not wiggism, it's not wigg history where we judge the past on the basis of the present because we kind of know better, we've learned more and we know better than they did in the past. But it's triumphalism where we celebrate the winners just because they're the winners of any scientific revolution or debate irrespective of the actual performance of their theories and methods according to current standards. So triumphalism and wiggism can go together. He thinks actually this is a case where they come apart in some respects. And this shows he thinks that triumphalism and wiggism, it's really the triumphalism that is the problem for historians of science. There's a great quote about his alternative conception that I want to leave you with today at the end here. He says, Hasek Chang says, a straightforward and effective antidote to triumphalism is a sympathetic historiographical focus on the losers. We could adopt this as a methodological directive, pay particular attention to the losing side in a past scientific debate, and do your best to construct and understand it as a sensible alternative that unfortunately got dropped. You should learn a great deal from this exercise. And Chang himself has done this for a lot of different ideas in the history of science that unfortunately got dropped. And he's actually gone so far as to reconstruct and conduct experiments based on old approaches, old paradigms to demonstrate that they actually did get the experimental results that they got, which are puzzling from a contemporary point of view. It's a very interesting work on batteries and some very interesting work on the radiation of cold rather than heat, which doesn't make a lot of sense from our contemporary perspective. So that's my little introduction to the Chemical Revolution and our readings from Honigun, Huna, and Chang on the Chemical Revolution. I look forward to speaking with you in class today about those things. Please feel free to respond to this video also in the Discord or in the comments section on the video. And otherwise, I will see you next time.