Talk:Falsifiability

Some concepts to put falsifiability in context

Pragmatism and strong belief

According to Godfrey-Smith, in the view of pragmatists, the main goal of language and thoughts is practical problem solving. The theory must answer a question about the world of observations. If the theory answers the question well, then one is justified in believing in it. The question Hume was asking is how observation can be used to justify this belief. Peirce outlines three stages in the process: abduction, deduction, and induction. In the abduction phase, theories are presented for consideration. In the deductive phase, they are prepared for tests. In the inductive phase, test results are evaluated.. To give a context to refutability, the most important thing is the existence of a deductive phase that exists purely at the theoretical level and serves to prepare tests. Refutability is simply the requirement that these tests be possible at this theoretical level. In this sense, the refutability criterion was implicit in Peirce. The most important difference between Peirce and Popper seems to be Popper's rejection that testing is an inductive process that leads to strong belief. For Popper, whether at the psychological level or at the objective level, there is no inductive, i.e., non-deductive, rigorous process that leads from observations to belief. According to him, the belief relates, on the contrary, to the conjectures that exist before the observations and any change in the belief due to corroborations can be justified deductively. He does not deny that we have the strong belief that if the tests are successful then the theory can be trusted, but he denies that this belief is a mental habit created by repetition. For him, it is innate, the result of an evolutionary process. On this respect, he somewhat joins Chomsky and other philosophers who believe that we have innate mechanisms at the level of language. He accepts that there is a form of induction in this evolutionary process and he calls it quasi-induction. Dominic Mayers (talk) 16:06, 26 March 2022 (UTC)

I don't think Peirce used the term "strong belief"; I searched several collections of his writings and the term does not appear in them. Peirce in fact distnguished between the "method of tenacity" and the "method of science", implying that in science belief is not tenacious belief, i.e., not strong belief. In questions of probability, Peirce also opposed (what we would call) subjectivists who equated probability with strength of belief. For an overview, see the section on probability, versimilitude, and plausibility in the SEP article on Peirce, e.g.: "Peirce is often considered to be the originator of the sort of 'propensity view' of probability that is associated with Karl Popper. [...] In rejecting Bayesianism and the method of inverse probabilities, Peirce argued that in fact no probability at all can be assigned to inductive arguments. Instead of probability, a different measure of imperfection of certitude must be assigned to inductive arguments: verisimilitude or likelihood." Peirce and Popper are, of course, very different philosophers in many ways, but I doubt that "strong belief" is an issue that separates them, given that Peirce never uses the term. Biogeographist (talk) 15:55, 31 March 2022 (UTC)

For example: "The difference comes to this, that the practical man stakes everything he cares for upon the hazard of a die, and must believe with all the force of his manhood that the object for which he strives is good and that the theory of his plan is correct; while the scientific man is above all things desirous of learning the truth and, in order to do so, ardently desires to have his present provisional beliefs (and all his beliefs are merely provisional) swept away, and will work hard to accomplish that object. This is the reason that a good practical man cannot do the best scientific work. The temperaments requisite for the two kinds of business are altogether contrary to one another. This is above all true of the practical teacher [who] has no calling for his work unless he thoroughly believes that he is already in possession of all-important truth, with which he seeks by every physiological means to imbue other minds, so that they shall be unable to give it up. But a scientific man, who has any such immovable beliefs to which he regards himself as religiously bound to be loyal, cannot at the same time desire to have his beliefs altered. In other words he cannot wish to learn the truth." Peirce, Charles Sanders (1935) [1898]. "The backward state of metaphysics". In Hartshorne, Charles; Weiss, Paul (eds.). Collected papers of Charles Sanders Peirce. Vol. 6. Scientific metaphysics. Cambridge, MA: Harvard University Press. p. 3. ISBN 0674138023. OCLC 783138. Biogeographist (talk) 17:19, 2 April 2022 (UTC)

@Biogeographist:, I know this is old, but I realize now that I did not answer. I do not disagree with what you wrote, except that you misinterpreted my use of the qualifier "strong". I used the term strong to acknowledge that even excellent scientists strongly believe in the correctness in practice of their laws, not to mean that they believe in the fundamental truth of any scientific law. I already at the time understood very well that Peirce considered that laws were not fundamental truths and that we will find better and better laws. I agree that on this respects there is no difference between Peirce and Popper. Still, Peirce referred to an induction step that was needed to create a belief, call it a weak belief if you want, whereas Popper rejected that observations would even contribute to a belief. For Popper, the belief must be there even before the observation, but this belief includes, of course, the provision that tests must succeed. Therefore, the only way an observation contributes to the belief is that it is not rejected if it does not contradict the law. As Miller says, from a logical standpoint, there is a "free entrance" in the domain of believed laws and the methodology only removes the laws that fail. (But even this removal process is fallible.) I never seen this clearly discussed by Peirce and the idea of an induction phase to create beliefs, weak or strong, seems to go in the wrong direction. Popper acknowledged, of course, that there is a reinforcement of a belief when it is not rejected by a severe test. It's possible that it is exactly what Peirce meant by an induction process, but, if. that is the case, I don't blame Popper to have been confused by this choice of terminology. I would not call this induction. Dominic Mayers (talk) 15:31, 26 October 2022 (UTC)

Yes, the meaning of "inIduction" (and probably of "belief") was different for Peirce and Popper. I discovered that Peirce did use a term similar to "strong belief", namely "firm belief", in his early article "The fixation of belief" (1877), where it is equivalent to "settled opinion" and is the opposite of doubt. I agree that from Miller's point of view Peirce seems to go in the wrong direction, but Miller is talking about a change of laws in a logical/formalistic sense whereas Peirce is talking about a change of mental states in a psychological/naturalistic sense. There is no formal logical level to Peirce's concept of belief; it's purely psychological. Falsifiability as a logical criterion is completely irrelevant to Peircean belief: "as soon as a firm belief is reached we are entirely satisfied, whether the belief be true or false". The 1877 article contains this little bit of incipient evolutionary epistemology (of biological mechanisms not of formal theories): "Logicality in regard to practical matters (if this be understood, not in the old sense, but as consisting in a wise union of security with fruitfulness of reasoning) is the most useful quality an animal can possess, and might, therefore, result from the action of natural selection; but outside of these it is probably of more advantage to the animal to have his mind filled with pleasing and encouraging visions, independently of their truth; and thus, upon unpractical subjects, natural selection might occasion a fallacious tendency of thought." Biogeographist (talk) 03:15, 28 October 2022 (UTC)

I am not sure how the concept of belief in laws in Popper is different, if different at all, from its counterpart in Peirce. I haven't read a lot Peirce and I would be happy to figure out that part more clearly. I know that in Popper the concept of belief, in many occasions, is this informal non rigorous, psychological, etc. state of mind in which we accept to use a law with conviction. Miller does not say, to my knowledge, that the free entrance in the domain of science must come with a belief. It's me that added that to the notion of "free entrance" used by Miller. I felt it was fine to do that. because, irrespective of what Miller says, the laws that have entered the domain of science, are accompanied with that kind of beliefs, which exist before any observation, but are reinforced by observations, because the belief includes the provision that the law must pass severe tests and when it does pass these tests, something is gained. Popper discussed this psychological aspect much more than Miller did. He tried to formalize it a bit using verisimilitude, but he did not succeed. But even that formalization would not have allowed to measure the belief in the law. It would only have been a theoretical model. Given that he did not succeed, the notion remained purely informal. The difference that I see between Popper and Peirce, but again I would be happy to figure out that part more clearly, is that, apparently, Peirce says that there is a method called induction to create beliefs in laws. There is no such method in Popper. There are only the use of severe tests and when a law is not rejected by these severe tests, of course, the belief is reinforced. What I don't know is what Peirce meant by this process of induction to create beliefs. I would be very happy to learn that it is the same as in Popper. Then the difference between them would only be the choice of words used, which is superficial, not in their view of science. Dominic Mayers (talk) 04:13, 28 October 2022 (UTC)

The myth of methodological falsifiability

It is often suggested that Popper defines refutability at the logical, i.e., theoretical level, but then changes the definition and that refutability, in practice, requires that the theory can be methodologically refuted. The argument given is that Popper says that, without methodological rules, refutability does not guarantee that the system is scientific. This argument ignores the importance of distinguishing between the logical and methodological levels in order to avoid false problems at the methodological level. The goal is not rigorous refutation, which is impossible, but only to allow critical discussion. Really, the whole idea is to separate the logical criterion which is easily and rigorously verifiable from the methodological rules which are also, it is true, important, but necessarily informal although sufficient for the intended objective. The logical criterion is very useful and works well in the context of these rules and the intended purpose. If we do not understand this, we have missed a central point. Dominic Mayers (talk) 16:06, 26 March 2022 (UTC)

Bibliography

• Godfrey-Smith, Peter (2003). Theory and Reality: An Introduction to the Philosophy of Science. University of Chicago Press.
• Magee, Brian; Morgenbesser, Sidney (1987). "The American Pragmatists: Dialogue with Sidney Morgenbesser". In Brian Magee (ed.). The Great Philosophers: An Introduction to Western Philosophy: Based on the BBC Television Series. Oxford University Press.

Subtle but important point regarding the material condition.

This edit and this one, both, have a useful purpose. The first one brings out that, being a logical criterion, we should not care that the actual devices exist. It should be sufficient that it can be built. The second one brings out that the way to build the devices must exist, which means that some technologies must exist and, therefore, it is not accurate to say the technologies need not exist. The material condition is at the junction point between existing technologies (the material aspect) and the logical world of statements. This is what the extract from Nola & Sankey quoted by Biogeographist says. Perhaps the text could still be improved to make clear that an « empirical test » is not something abstract, but something that can be physically executed given the intersubjective knowledge, even if the context is a « logical criterion ». Dominic Mayers (talk) 22:41, 11 February 2023 (UTC)

Yes, that's why I removed mention of "existing technologies" instead of doing a clean revert. I couldn't think of an easy way to explain all that. Biogeographist (talk) 22:47, 11 February 2023 (UTC)

I understand. When I see that editors, including User talk:Profnnmm, are making subtle modifications that all show a reference to sources, I do not worry. I mean, in particular, the understanding that the material condition has nothing to do with actual tests and therefore, no actual specific devices need to be referred to, is certainly verifiable in sources. Dominic Mayers (talk) 22:52, 11 February 2023 (UTC)

I propose to undo the last edits by IP 140.78.5.108

The current article does not hide that many philosophers had a different view than Popper and that, even recent philosophers think that the criticisms of Lakatos, Kuhn, etc. were valid. If this is not clear in the paper, I think it should be made clearer. However, the words "claimed", "thought" and similar words in expressions such as "Popper claimed" and "Popper thought" are not neutral at all. They suggest in Wikipedia's voice that Popper was wrong. Wikipedia must present the view in a neutral manner without suggesting it is wrong. Added texts such as "since Newtonian physics does not deny that there could be forces acting on the apple that are stronger than Earth's gravity" even argue in Wikipedia's voice why Popper was supposedly wrong. I always say that there is a need to understand the sources, in this case Popper, before we can write a Wikipedia article, because, otherwise, there is a risk that we attribute the incorrect view to a source when we criticize it using other sources. This is a subtle point: a criticism often, especially in Popper's case, attribute incorrectly a view to the source that is criticized. These criticisms are kinds of strawman fallacies. In these cases, it should be made easy for the readers to see that it is a strawman argument. The misunderstanding is that falsifiability is a logical criterion, not dependent upon the actual laws, except for the material requirement. This is indeed a very subtle and difficult point to understand. Not surprisingly, the IP did not understand it and, because of that, has misrepresented Popper's view. Instead of reading the article to understand that Popper used the basic statement "an apple that moves from the ground up to a branch and then starts to dance from one branch to another" to make clear that falsifiability has nothing to do with whether Newtonian physics denies or does not deny that possibility, the IP presented his personal argument that Popper is wrong because Newtonian physics does not deny it. It's so discouraging. The article explains it so clearly and yet some readers miss the point. I do not think the fault is in the article. It is a difficulty intrinsic to the concept of falsifiability. The difficulty is that falsifiability is practical, about practical experiments, because of the material requirement, but at the same time it has nothing to do with whether or not the law actually contradicts real observations. In the example of the apple, the material requirement is respected, because it is actually possible to measure the position of an apple at different times. The fact that Newtonian physics does not deny that there could be forces that make the apple dance in this way is irrelevant. Referring to this is clearly a strawman argument. It would be relevant if falsifiability was about the possibility of methodologically proving the law false, but this is impossible and it is not required for falsifiability. Clearly, Popper knew it. For some reason, Lakatos could not abandon the idea that falsifiability is about methodologically proving the law false and he argued that it was impossible using arguments similar to the one presented by the IP. Of course, we cannot methodologically prove the law false, for example, because Newtonian physics does not deny that their could be forces that explain the movement of the apple. In a way, falsifiability is a very simple criterion. One simply needs to look at it at the purely logical level (except for the separate material requirement): one needs only to consider the language in which the laws is formulated and whether one can, in that language, build a statement that contradicts the law and yet respect the material requirement. Nothing more than that. No consideration of whether or not we can actually conclude methodologically that the law is false. Dominic Mayers (talk) 17:20, 5 March 2024 (UTC)

@Dominic Mayers: I think you have justified your proposed reversion well enough that you can go ahead and do it. If the IP editor wants to come and argue against you, they can. The IP edits as written are vulnerable to your rebuttal. However, there may be a more interesting argument in Stove (see web version here: chapter 5, section 4) that that the IP editor missed, which is (if I understand it correctly) that Popper asserted that certain statements are falsifiers of Newtonian physics, but Popper did not make a valid deductive argument showing that the statements are falsifiers, and the statements could be considered merely logically independent of Newtonian physics. In this regard, Stove especially takes umbrage at Popper's claim that "almost any statement about a physical body which we may make [...] would contradict Newtonian theory" (emphasis is Stove's). Stove calls this "mere bluff". Biogeographist (talk) 20:29, 5 March 2024 (UTC)

Yes, I believe that Popper in some texts has followed others such as Lakatos in speaking of contradictory universal laws, but the context was the possibility of initial conditions. I don't think it is fair nor interesting to make a big deal about the fact that some times, perhaps often, they neglected to make explicit that context. It's the contrary: it is Stove's rejection of that context that is not natural. He is logically correct, because logically it is possible that the universe is empty and, therefore, the appropriate initial conditions are not possible. However, these philosophers were excellent logicians and it is not serious to attack them at that level. On the contrary, Popper was very careful at the logical level in the analysis of his criterion. If Stove would have argued like that with Popper and Lakatos they would have raised their eyebrows and ignored him, because, of course, they were aware of this logical fact and it is not serious at all to assume that their philosophies fall apart because they would have failed to take into account that kind of logical facts. I decided to read Stove's article How Popper's Philosophy Began (1982), published the same year as "Popper and After: Four Modern Irrationalists". The paper makes some valid points in its first pages, but it starts to really misrepresent Popper with the sentence Consistency with every observation-statement, if it is a defect at all in a theory, must be a very trifling one. For it is a property which Marxism, for example, shares with such superlatively good theories as Newtonian physics, ... He misses the point that unfalsifiability => no predictive power, which is certainly a defect. His arguments against falsifiability, when applied to predictive power is that no theory (including Newtonian physics) has predictive power and, therefore, lack of predictive power cannot be a defect. But, of course, Newtonian physics has predictive power and if it did not, it would not be useful. Stove is really misunderstanding the distinction between the necessary material requirement and the too strong methodological requirement of knowing facts or laws to be true. Popper has always been aware that there is no way to be sure that a contradictory observation statement is true, because errors are always possible in measurements. He was also aware that, even if they are no errors in the observations, they can be made compatible with a law by introducing some explanations for the apparent contradictions. Popper just generalized and discussed more formally an argument that is also needed to justify the merit of predictive power, but which we don't bother to give in the case of predictive power. I think it is important to present an argument for the merit of predictive power, even in the presence of methodological problems (errors in measurements, ad hoc explanations, etc.) and this is what Popper did for the more general falsifiability criterion. Stove missed that point. Dominic Mayers (talk) 00:10, 6 March 2024 (UTC)

The lede

I've done some reparagraphing of the lede just for clarity. But it brings out that the sentence about "some philosophers such as Deborah Mayo" is out of place in the lede. Obv., Popper's views have critics, but this does not seem to be the place to cite Mayo in particular. This material could be eliminated from here, or there could just be a reference to the fact that there are critics of Popper's claims. The detail can come later. The point is that the lede paragraphs are meant to provide a summary/overview about the significance and substance of a topic. Adding details that don't match that description will come across as jarring to the reader and may mislead about what is most important. Metamagician3000 (talk) 08:47, 15 March 2024 (UTC)

Just to say that Popper's view has critics would be pointless and even misleading. The readers must be able to make their own judgment when they read the criticisms and be able to see them for what they truly are. This need for a context does not mean that they do not belong in the lede. Even the confusion that exists in the literature about falsifiability is an essential part of the subject. I know that it is a very difficult task, because the readers could easily get confused, if they expect to be simply told what falsifiability is. When criticisms are presented, they might think that it is because falsifiability really deserves them. But the other options, saying only that criticisms exist or completely ignoring them, seem unacceptable to me. The article must explicitly and clearly consider the confusion that exists in the literature and this aspect is important enough that it must be present in the lede.

There are two aspects in Popper's philosophy. The first is that it presents the very common view that predictive power and the existence of experimental tests are key features of science. Popper formalized and generalized this view with the falsifiability criterion. The second is that there are still today many philosophers that criticize the criterion with arguments that apply also to predictive power and the existence of experimental tests. For example, they might not realize that the Duhem-Quine problem says also that no law has true predictive power, because we can never be certain about these predictions. Because he understood very well the Duhem-Quine problem and similar problems, Popper provided a criterion to resist them. This is exactly why he insisted that falsifiability is a logical criterion. If it was only the non educated public that misunderstood this aspect of Popper's philosophy, I would say that you are right, but those who still apply arguments against Popper's philosophy that also apply to predictive power are professional philosophers. Mayo and Stove are examples. I am not saying they reject predictive power as a fundamental criterion, but I think they miss what Popper attempted to do (and succeeded in doing so in my view). He wanted a clear criterion that covers the natural notion of predictive power and resists the Duhem-Quine problem and other problems that he refers to as methodological problems without pretending that these problems have a solution at their own level. He accepted that there are no solutions to Hume's problem, to the Duhem-Quine problem and to other methodological problems. He understood that the Duhem-Quine problem takes a step back on his separation logical versus methodological and correctly says that the methodological problems are still there. He never denied that. He even gave his famous swamp analogy: "the bold structure of its theories [the logical side] rises, as it were, above a swamp [the methodological side]. It is like a building erected on piles". This misunderstanding of Popper's philosophy is a significant part of the literature on falsifiability. It seems to me that, on the contrary, it must also be a significant part of the article and this must be reflected in the lede.

I do appreciate your concern, however, because presenting this situation is a very difficult challenge, but I do not think it is a challenge that can be avoided. Dominic Mayers (talk) 17:15, 15 March 2024 (UTC)