[Music] Hi there, welcome back to History and Philosophy of Science and Medicine. I'm Matt Brown. Today is part three of our discussion of Feyerabend's book Against Method. We're talking primarily about chapters 15 and 16 and the interstitial appendices there. So in these chapters, Feyerabend is attempting to sort of wrap up the main argument of the first part of the book, right, really the primary focus of the book, which is the argument against method, right, against the notion that there's a single scientific method that unites all of the diverse activities that we call science. And he's trying to do so in but by responding to some ideas that might you be used against the main part of his argument, right. So just to remind you, the main part of Feyerabend's argument against method stems from, on the one hand, the Galileo case. Galileo violates a variety of empiricist prescriptions of scientific method by using, by essentially using what Feyerabend calls counter-inductive approaches. And Feyerabend also provides

um sort of scaffolding or um supplementary theoretical abstract arguments that go along with the historical arguments. That this is a reasonable set of things for Galileo to do, I mean. And in the background, of course, is the idea that Galileo is an important figure in modern science. And so we should regard sort of by default the things that Galileo was doing as at least permissible aspects of science, if not exemplary. So in Chapter 15, Fire uh considers uh some some um some responses to his his argument. The main one is based in a classic logical empiricist distinction between the context of discovery and the context of justification. So the context of discovery is supposed to be that part of science where scientists discover new phenomena, pose new theories, come up with new theories, and do all of the messy things that scientists do to um to arrive at their at their ideas and conclusions. And then the context of justification is supposed to be that part of science where those those results, those theories, hypotheses are logically justified on the basis of

the evidence that is gathered now many thinkers and at fire robin's time and sense have questioned this distinction between the context of discovery and the context of justification and fire oven is is no difference he is no different here and he he largely points to the fact that these processes are entangled in practice right as the main argument but he also points out as he's done throughout the book that the strict sort of application of the methods that are supposed to apply just to the context of justification would still wipe out broad swaths of science including including galileo's innovations right the the the practical impossibility of making the distinction um the overly restrictive notions of what happens in the context of discovery and um and also the the the need for the close interaction between the two in order to criticize abstract uh uh theories of method uh is they're all parts of fire robin's argument against this distinction there is i think a distinction in the neighborhood that's relevant to think about i wouldn't call it the context of

discovery versus justification. But there is, um, there are two processes that tend, uh, to be somewhat separable in science, and that's what you might call the context of inquiry when a scientist, or more likely a team of researchers in a laboratory, conduct experiments, propose theories, and, and then publish their results, and then the context of certification where those, those publications are peer-reviewed, published, and then potentially taken up by other members of the scientific community. So, I think that there is an interesting difference there, but it's not one that lines up with the, with the philosopher's attempt to draw a difference between the, the history, the historical process, the messy history of science that happens in the context of discovery, um, and the philosophically interesting, uh, process of justification. Um, justification happens in both of the, the real-world context of inquiry and the context of credibility in attempting to, uh, oppose the context distinction. Fire Robin also raises, uh, objection to a similar distinction between prescription and description. He's particularly thinking of methodological prescription for science and historical description of how science actually works.

um now i i mean i think fire robin doesn't mean to say that there's there's no meaningful distinction to be had there rather what i think fire robin says is that there's an important way in which the descriptive and the prescriptive interact right so so um philosophical prescriptions are tested in the history of science and by the history of science in a sense um and uh uh they're they're um they're important ways in which not only can you criticize happenings in the history of science based on methodological prescriptions you can criticize methodological prescriptions as unrealistic or inapplicable or irrelevant by looking at how they would work out in the history um so if there there's of course there is some kind of distinction between ot and is um but it's sort of it's it's not as fundamental as you've as some philosophers have led us to believe um there's also a lengthy distinction or a lengthy discussion rather of critical rationalism which i won't try to repeat here

um, but rather, I think what's most interesting about it is the way in which Fire Robin talks about different conceptions of scientific progress from one theory to the next. Right, so he has this diagram. It's on page 159 in the fourth edition. It looks like this, right? So the first, the top diagram here is sort of how Fire Abandoned thinks, um, we tend to think of the history of science, right? So we tend to think, you know, the old theory was okay, but it wasn't as good as the new theory. The new theory has increased content and, um, and the relationship between the two is one of growth. The knowledge has increased, right? Um, but in fact, what Fire Evan points out is that this version of the old theory is kind of a fiction. It's kind of a construction from the perspective of the new theory. So the old theory wasn't this. Isn't really what the old theory was. This is a version of the old theory which has been kind of sanitized and

rendered compatible with the new theory. Another version of that is one where we admit, Okay, there were some things that the old theory got wrong, but still, there were parts that it got right. And the parts that it got right here are explained by the place of those sort of predictions in the new theory, right? And so it's still, it's still a matter of empirical growth, right? Growth of empirical content, right? In fact, on Feyerabend's conception, it really works more like this, right? First theories are much more open-ended on Feyerabend's conception. So, you know, we, we, we know to some extent what the old theory and the new theory say, but they make a kind of open-ended, they have a kind of open-ended content, a kind of, you know, a variety of different ways in which the basic commitments can be developed by further research. So, the fact that they're not closed here in the diagram, that's what that represents, is the open-endedness.

the other is that the um, the shared content, such as it is, is also kind of a kind of a distortion, kind of a kind of a construction, right? So, um, there is stuff that the old theory predicted that seemed fairly successful, and this gets shoehorned into the new theory, um, but because in part of what Fireman calls the incommensurability between the two theories, um, it's not, it's, it's, you know, the idea that it's shared content is a little bit of a fiction as well, right? Um, so, so, but the and so, so what you have is sort of a, a replacement of the old theory by the new theory, some shared content, but only sort of, and really it's, it's more of a replacement of focus and emphasis, uh, going on there. Now, I just use the word incommensurability. We've talked about it a little bit before, but this is really a major focus of these chapters. So, let's talk about, let's talk about it for a moment, incommensurability.

for fire abandoned means to some extent incomparability right that's where the word comes from right so um one of the original uses of the word or the home uses of the word incommensurability is in mathematics to describe for example the relationship between the length of the side of a square and the length of a diagonal. Okay, the length of the side of the square and the length of the diagonal are incommensurable in the sense that the length of the side of the square is one right. The um length of the diagonal is the square root of two and there's no there's no um finite number or a decimal or fraction that you can use to express those numbers in the same system right. If you switch to treating the diagonal as a whole number, then you're going to get an irrational number for the sides. Of course, they're comparable in a sense like you can mark the you can mark the approximate um links on one ruler and you can see one is longer than

the other they're comparable in that sense, but they're not rationally comparable. They're not, they can't be um, they can't be um made part of the same sort of accounting system, right, insofar as that uh means, you know, having a finite representation in the same in the same numerical system, right. Uh, so too, fire robin thinks that scientific theories are incommensurable, um, insofar as there's no rational logical way to line up all of the concepts, laws, claims, predictions, um, evidence, experiments for one theory and another theory to to compare them one to one, right. The conceptual change that that accompanies the move from one theory to another means that there is some ambiguity, some slippage, uh, between the two, right, um, some change of not only theoretical but also perceptual content. In fact, in these chapters, uh, fire evan tells us that it's not just that our perceptions or our um, observations are influenced by theory to some extent, they're uh, they're, they're actually fully theoretical, right. Observational claims are fully um, uh.

informed by our theoretical commitments, right, we can of course within a framework on a pragmatic basis distinguish between something that's an observation and something that's a theoretical claim, but there's no, there's no sort of in principle difference between between the two, right. Any, any kind of commitment is on the same ground as another kind of commitment, so um, that's incommensurability. Fire Robin tells us incommensurability is a philosopher's problem, not so much, uh, not so much a scientific problem, right. It has to do with the way that philosophers want to rationally reconstruct, logically reconstruct scientific activity, and not so much with, um, the activities that actually scientists engage with. Scientists are more comfortable with ambiguity. They can make these comparisons just like an engineer, right, can compare the side and the diagonal of a square for length, right. So it's a sort of artificial problem, but it is one that helps to undermine, uh, rationalist conceptions of scientific method. Um, in chapter 16, Fire Robin has a very, a very long description of

ancient cosmology. He's really in the sense of the ancient world view in relation to art, mythology, science, language, and his argument. There is that one's conceptual system, um, is, uh, influential on what not only one, what one believes about the world, but the way one sees the world, right. This sort of a tight connection between concepts and and and perceptions, right, um, and so, uh, uh, it's a, it's a, it's a, it's a rather long description of that, but the key idea, I think, to, to connect it to scientific method. The key idea is, um, that when you change from one theory to another, when you change from one language to another, and all these associated conceptual changes that go with that, to a certain extent, one is perceiving a different world, and the facts that one, um, believes, right. The, the, the, one one's beliefs about what the evidence says, what the facts are, will change, in effect to use language from Thomas Kuhn, uh, when you move from one conceptual framework to another, you're, you're

living in a different world so so that's um that's what's going on i think in this third part of the book um uh to sum up um uh you know scientific practice is much more complex than the philosophical rationalist would have you believe. Plurality, variety, creativity, you might say complexity, are all important parts of of science. From the perspective of the philosophical rationalist, disorder and chaos are essential to knowledge and its progress. According to fire abandoned, the way to really understand science is to look at how it unfolds historically and to to to some extent to give space for the scientists to um proceed proceed creatively. And you know one of the I mean one of the things that fire robin I think is is trying to get us out of is is is rigid conceptual systems that impede the progress of science, right that's that's a big part of what's going on in the first three quarters of the book. Part four will start to get outside of the of science per se um and

into a broader view. Um, and but we'll save that for the next video. All right, see you next time.

Paul Feyerabend, The Case Against Method and Incommensurability

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