Talk:Falsifiability/Archive 4

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Theories as Tools

As an engineer, I view scientific theories as tools - I choose the best theory for the job at hand. Newtonian mechanics is less accurate, but very easy to use. Quantum mechanics is much more accurate, but is too cumbersome for most problems. If I'm trying to calculate the motion of everyday objects like cars, birds, and bullets, then Newtonian mechanics works fine. But if I need to calculate the mass discrepancy in a high-energy particle stream, I must use a relativistic model, and the Newtonian "tool" will not work. My point is that one reason "falsified" theories still exist is that each is useful for solving a particular class of problems. So perhaps scientific theories should also be viewed (and presented somewhere in the main article) from the standpoint of applicability or relevance to a particular task. This may help to explain some of the confusion concerning the persistence of "falsified" arguments and theories. — Preceding unsigned comment added by 129.55.200.20 (talk) 16:44, 15 October 2012 (UTC)

Thank you for your help, but Wikipedia does not accept original research, but relies on reliable secondary sources. Ian.thomson (talk) 16:49, 15 October 2012 (UTC)

Swannage

The photo of black swans contributes so much to this article. Black-Velvet 03:20, 22 November 2012 (UTC)

For hundreds of years in European cultures, "black swan" was a proverbial phrase for something non-existent, then all of a sudden explorers visit western Australia, and behold, black swans... AnonMoos (talk) 05:35, 22 November 2012 (UTC)

Well, Perth is generally known as the city where all your dreams come true. Black-Velvet 14:04, 24 November 2012 (UTC)

John Stuart Mill left out?

Although this article states that Popper "popularized" the concept, it does tend to give the impression that Popper was the originator of the concept at least as far as is known. This isn't my area of expertise, so rather than editing the article myself, I'd rather just point to the online Stanford Encyclopedia of Philosophy's section on the scientific method. It states that Mill's idea "is what has come to be called the 'covering Law' model of explanation or the 'deductive-nomological' model. Positivists such as C. G. Hempel came to accept this model, as did K. Popper. But contrary to Popper's claim to originality, Mill is the first to clearly state this model."

http://plato.stanford.edu/entries/mill/#SciMet

DoItAgain (talk) 02:45, 17 January 2013 (UTC)

Scope Creep?

I was in the process of adding citations to the existing content and I realised that this article may be exceeding the scope that its titles suggests. It seems to me that some of the content belongs in Critical rationalism. Should the article not be concerned with the notion of falsifiability simpliciter rather than the Popperian concepts that surround falsifiability in Popper's epistemology? AnotherPseudonym (talk) 11:17, 21 September 2013 (UTC)

I differ in your WORD meanings

"Testability, a property applying to an empirical hypothesis, involves two components: (1) the logical property that is variously described as contingency, defeasibility, or falsifiability, which means that counterexamples to the hypothesis are logically possible, and (2) the practical feasibility of observing a reproducible series of such counterexamples if they do exist. In short, a hypothesis is testable if there is some real hope of deciding whether it is true or false of real experience. Upon this property of its constituent hypotheses rests the ability to decide whether a theory can be supported or falsified by the data of actual experience. If hypotheses are tested, initial results may also be label(l)ed inconclusive." [[1]] General concensus2012 (talk) 19:18, 17 December 2013 (UTC)

Contrary or specifically, falsifiability [[2]], has the root word from "falsifiable" and "false". Meaning that it can be made or proven to be false. And has a general meaning in that, it can be a false/falsifiable belief, or falsifiable by instrumentation. This means it can be studied by either the Scientific Methods or by logic analysis.

Testability is the specific definition from root words of a "test" and "testable". And of what can be testable or not. Something can be or cannot be testable solely by instrumentation and scientific observation by the senses. Testability does not denote persee anything to do with it being false, falsifiable or falsifiability, by the mere word root definition. A test is a test and specific. A test does not mean in its word roots that it can be falsifiable.

What can be falsifiable is hence, a test or a logic statement or belief. And thus has these two components. It is not Testability that has these two components.

It is for wikipedia to decide over this. General concensus2012 (talk) 19:44, 17 December 2013 (UTC)

Future fixes

Simplify the following:

. . . process of conjectures and refutations, while conjectures have no logic but are creative, while refutations are strong attempts to falsify the theory and reveal its shortcomings so that . . . .

Broken or ?

New(ton?) rejected the concept of aether, and presumed that space was normally empty, so as to not (to interfere?) interference with the putative (why so complex?) force gravitation traversing (??) the entire universe at instant speed, instant interaction at a distance.

For later . . . . -- Rednblu (talk) 17:22, 31 December 2013 (UTC)

This article requires complete revision. I would suggest that it is not comprehensible even to most science graduates. The philosophical discussion has obscured its practical application. Since most philosophers are not trained in science and most scientists are not trained in philosophy it's poor use of language (other than technical philosophical jargon) has made it irrelevant to up and coming science graduates and high school students. These are the very people who should be edified by the article. As a science educator I would request an expert revision which would be most welcome. At present I can make nothing of it which would inspire my students and will stick to induction. Open minded though I am the case for falsifiability needs to be made in comprehensible English. — Preceding unsigned comment added by Jimmy Maxwell Jaffa (talk • contribs) 20:18, 14 December 2014 (UTC)

misqouted

Moved from art misquoted example. Review history for detail.

For example, the assertion that "all swans are white" is falsifiable, because it is logically possible that a swan can be found which is not white. Not all statements that are falsifiable in principle are falsifiable in practice. For example, "it will be raining here in one million years" is theoretically falsifiable, but not practically so.

I agree. --Palladipeloarancione (talk) 17:28, 23 May 2015 (UTC)

Falsifiability?

Most of science cannot be falsified. We cannot say that if the sun did not exist then this would happen. We cannot remove the sun to see the alternative. There are only a small number of branches of science that can be falsified. This needs to be pointed out in this article. 206.172.0.200 (talk) 13:08, 3 May 2016 (UTC)

Proved and Proven

Chaos5023 comments:

assertion that "proven" is exclusively an adjective is dramatically inconsistent with English usage …

and I agree. Fortunately no one is making that bold an assertion, so let's call this part "case closed".

Chaos5023 continues:

… and previous form [proven] is the more common idiom by a good margin

and I disagree. The question then becomes one of finding citations that discuss which form dominates. Googling "Proved vs. proven", the first hits are:

1. Proved vs. proven - Grammarist: "Proven is usually an adjective (e.g., a proven formula), and proved is usually the inflected form of the verb prove (e.g., I proved it; I have proved it). This is not a rule, though …"
2. Proved vs. Proven - Daily Writing Tips: regarding the verb form, says that the OED supports proven and that the Chicago Manual of Style and the AP Stylebook advise against the use of proven. It summarizes that both are acceptable to many but that 'British and some American style guides recommend proved as the only past participle, admitting of established set phrases like “innocent until proven guilty.”'
3. - What is the difference between "proven" and "proved: says that both forms are acceptable and doesn't weigh in on choosing between them, except that it provides historical graphs showing that "proved" dominated "proven" until recently, when now they are close to tied with "proven" barely ahead according to Ngram.
4. grammaticality - "Is it proved that ...?" vs. "Has it been proven that ...: is about perfect vs. simple, not "proved" vs. "proven".

Also see the wiktionary usage notes for "proven":

As the past participle of prove, proven is often discouraged, with proved preferred – “have proved” rather than “have proven”. However, they are both used about equally in everyday use. 𝕃eegrc (talk) 16:53, 14 July 2016 (UTC)

References

Claims about the meaning of 'pseudoscience'

How did "the practice of declaring an unfalsifiable theory to be scientifically true [come to be seen as] pseudoscience"? Could we question this claim more historically (than conceptually)? What is its etiology? Surely any claim in Wikipedia should have an etiology or history which can be identified and documented clearly as a lineage? MaynardClark (talk) 00:53, 22 August 2016 (UTC)

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There are gorillas in Africa

I read the article and I cannot determine whether there are gorillas in Africa is falsifiable. Perhaps this example or a similar example should be considered to clarify the meaning of falsifiability. Note that "There are big monsters in the Loch Ness" is the same kind of statements. If the latter is not falsifiable, then the former is even less falsifiable, because Africa is way more complex to search than a single deep lake. Unfortunately, I would not be able to add this example, because I don't even know if it is falsifiable, but definitively the article should clarify the issue. There must be some good references that discuss similar examples. Dominic Mayers (talk) 16:09, 15 April 2018 (UTC)

Link to Google Books as a source?

I had an exchange with Mauro regarding use of Google Book to cite Popper and others. The problem is that the pages that are shown in Google book depends on the country and may change over time. It's not reliable. Therefore, I suggest that we follow these guidelines. Dominic Mayers (talk) 16:13, 17 May 2018 (UTC)

Refocusing on falsifiability and using more of Lakatos

The biggest issue in the current version of the article, in my opinion, is that it does not define falsifiability very well. It's hard to define in a way that is suitable for an encyclopedia with a large audience, but we can succeed by explaining better what are basic statements, the role of space and time in these basic statements, the role of probability, etc. We should, of course, explain falsification and falsificationism, but only as a way to provide the context. (It is for that reason that I feel we should remove the section falsifiability#Contemporary_philosophers, which is not helping.) We should use more Lakatos view on falsifiability. The same notion of falsifiability is still there in Lakatos. Lakatos embraced falsifiability in its entirety. Lakatos did not disagree with Popper about the requirement of falsifiability for a (complete) theory. It only disagreed with Popper on falsificationism and not much in my opinion, but my opinion might be irrelevant. Here is what Encyclopedia of Philosophy says on this subject:

"[F]alsifiability continues to play a part in Lakatos’s conception of science but its importance is somewhat diminished. Instead of an individual falsifiable theory which ought to be rejected as soon as it is refuted, we have a sequence of falsifiable theories characterized by shared a hard core of central theses that are deemed irrefutable—or, at least, refutation-resistant—by methodological fiat. This sequence of theories constitutes a research programme.

...

"For Lakatos an individual theory within a research programme typically consists of two components: the (more or less) irrefutable hard core plus a set of auxiliary hypotheses. Together with the hard core these auxiliary hypotheses entail empirical predictions, thus making the theory as a whole—hard core plus auxiliary hypotheses—a falsifiable affair."

So, it's only the (incomplete) hard core that is not falsifiable. I would be curious to know what Popper responded to that, but in my humble opinion the fact that a falsifiable theory contains a hard core of statements that is not falsifiable is not surprising. In a way, mathematics is such an hard core. It is not falsifiable and yet it is behind most falsifiable theories. Anyway, the key point is that Lakatos embraced falsifiability as a criteria for valid (complete) theories.

By the way, the following sentence Instead of an individual falsifiable theory which ought to be rejected as soon as it is refuted is misleading in my opinion. It suggests that Popper falsificationism was that we must reject a theory as soon as it is falsified. This is not true, I think. First, it should be explained that Popper was very much aware that falsification requires more than a single observation. The current article is also misleading on this issue. It emphasizes too much that a single existential statement is sufficient to prove that a universal statement is false, as if this mathematical fact captured the entire notion of falsification. Popper explained clearly that falsification requires that a potential falsifier is sufficiently corroborated by repeated observations, just as we normally require in science. But, this is only a requirement, not a sufficient criteria to reject a theory. I would be very surprised that Popper had stated a decisive criteria to reject a theory. Dominic Mayers (talk) 16:27, 29 May 2018 (UTC)

More on the section Comtemporary philosophers

Clearly, the section Comtemporary philosophers, as currently presented, does not fit at all in this article. This is not an article about Popper. Just as an example, which sets the tone, the first sentence is Many contemporary philosophers of science and analytic philosophers are strongly critical of Popper's philosophy of science.. I do not propose to delete all the content as a whole, because some of the content could be reused in the context of falsifiability, but a clear connection will have to be provided. This article is about falsifiablity, not about other aspects of Popper's view on science, not about verisimilitude, not about research programs, etc. We should say something about each of these aspects, perhaps, but always in connection with falsifiability. In that sense, I am hoping that we can reuse some of the content of that section. Dominic Mayers (talk) 19:22, 9 June 2018 (UTC)

Invalid support for "Popper stressed that unfalsifiable statements are important in science."

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The footnote provided in support for the claim Popper stressed that unfalsifiable statements are important in science. is not reallly supporting the claim. The footnote says In reference to Kant, Popper wrote: "I do not think that his ingenious attempt to provide an a priori justification for synthetic statements was successful." This refers to Popper's response to Kant's solution to the problem of induction. According to Popper, Kant's solution to the induction problem was to accept the induction of universal truths from individual observations as "a priori" valid. Popper considered that this "ingenious attempt" was not successful. This can be seen at Popper 1956 pp.5-6. This footnote is not related in any obvious way to the importance of unfalsifiable statements. However, the claim itself is correct, but it needs to be better supported. Dominic Mayers (talk) 19:22, 9 June 2018 (UTC)

This has been taken care of. Dominic Mayers (talk) 19:26, 9 June 2018 (UTC)

More about the section Mathematics

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In this section, it is claimed that Popper viewed mathematics as being similar "to the natural sciences whose hypotheses are conjectures". As I mentioned earlier, the reference that is provided to support that claim cannot be found. It says "Popper 1995", but Popper left us in 1994 ... I looked in books written by Popper that were reedited in 1995 and found nothing that support that claim. On the other hand, here is an extract from Popper that clearly shows that Popper viewed mathematics as being non falsifiable:

"The problem of finding a criterion which would enable us to distinguish between the empirical sciences on the one hand, and mathematics and logic as well as ‘metaphysical’ systems on the other, I call the problem of demarcation."

— Karl Popper, The Logic of Scientific Discovery, p.11

So, again, we should remove this unsupported claim, i.e., the entire paragraph. This quote also shows that Popper did not want to demarcate between what can have a role to play in a scientific method and what should have no role in a scientific method. Clearly, Popper understood that mathematics has an important role in the scientific method. Similarly, in many occasions, Popper expressed the opinion that metaphysical systems are important in a scientific method. His demarcation criteria was only a way to separate between scientific or empirical statements on one hand and mathematical, purely logical or metaphysical statements on the other hand. Dominic Mayers (talk) 23:25, 3 June 2018 (UTC)

This has been taken care of Dominic Mayers (talk) 19:27, 9 June 2018 (UTC)

Presentation of facts about the Daubert standard are biased.

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The actual Daubert Standard does not mention falsifiability, in fact, it does not mention testing. It was only in the original version that the sentence "can be tested and has been tested" was found. It is relevant to mention that in the original decision there was an explicit reference to Popper's falsifiability, but any reference to falsifiability was removed in subsequent versions of the Daubert standard, because of criticisms. One of these came from the Chief Justice William Rehnquist and Associate Justice Jean Paul Stevens, who found this concept mysterious. In a separate opinion, they responded that:

"... Following [the first] sentence are three quotations from treatises, which not only speak of empirical testing, but one of which states that the criterion of the scientific status of a theory is its falsifiability, or refutability, or testability, . . . . I defer to no one in my confidence in federal judges; but I am at a loss to know what is meant when it is said that the scientific status of a theory depends on its falsifiability, and I suspect some of them will be, too."

— William Rehnquist, Kaye, David H. "On 'Falsification' and 'Falsifiability': The First Daubert Factor and the Philosophy of Science". {{cite journal}}: Cite journal requires |journal= (help)

This is OK now Dominic Mayers (talk) 19:28, 9 June 2018 (UTC)

Removing the external links section

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I propose to remove the external links section, because there are two external links, one is broken and the other is a link to the non technical definition of falsifiability in Wiktionary, which is not much related to the current article. Well, we can wait a bit in case it is only temporary down. Dominic Mayers (talk) 20:41, 24 May 2018 (UTC)

This is OK now. Dominic Mayers (talk) 19:30, 9 June 2018 (UTC)

The subsection mathematics of criticisms seems a personal opinion

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The references provided in this subsection are either incomplete or unrelated to the content. I tried as much as I could to find other references to support the content and found nothing. In my search, I could see that Popper has used Godel's incompleteness theorem, but it was in a different context. He used that to argue that sciences, physics, etc, were also incomplete. I also found books that copied word for word the section. One of them, cited "The Logic of Scientific Discovery", which is incorrect: in this book, Popper does not say anything that support the claim of that subsection. I propose to remove this subsection. Dominic Mayers (talk) 17:29, 8 May 2018 (UTC)

I asked the complete reference to the user who quoted Popper. https://en.wikipedia.org/wiki/User_talk:Everything_Is_Numbers#Incomplete_reference_for_a_quote_of_Popper_that_is_difficult_to_find . Dominic Mayers (talk) 00:28, 10 May 2018 (UTC)

This is OK now. Dominic Mayers (talk) 19:31, 9 June 2018 (UTC)

Bad title for the article

I wrote this section and it can be ignored. The title is perfectly fine. At first, I did not realize that, even though the notion of falsifiability was mainly supported by Popper the concept was reused by others such as Lakatos, though in a more holistic manner in the post-Popperian era. Dominic Mayers (talk) 19:37, 9 June 2018 (UTC)

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The first example in the Intro is:

   ... the universal generalization that All swans are white is falsifiable since it is logically possible to falsify it by observing a single black swan.

The definition of falsifiability should primarily apply to a valid hypothesis or theory - that's the idea.erefore, in our first example, let's use an hypothesis that is valid. For example, let's explain the falsifiability of the statement

   "Any two objects dropped from the same height above the surface of the earth will hit the ground at the same time, as long as air resistance is not a factor."

With this example, one must naturally adopt a different approach. We cannot argue anymore that we can observe a case where the hypothesis is false, because, given that the hypothesis is correct, there is no such a case. More specifically, we cannot say that the statement is falsifiable because we can "logically" find two objects that hit the ground at different times. A "logically" that allows the impossible is too strong and anything becomes falsifiable (see below). We cannot also start to argue in terms of a different universe, because this universe could be anything.

So, what is the correct approach? The correct approach is that the hypothesis is falsifiable because it says that the probability to find two objects that hit the ground at the same time is not negligible. In fact, the probability is one in this case - this is implicit in the phrase "Any two objects..." at the start of the hypothesis. This means that, if after trying a few objects (the first two objects are enough), we do not find that they hit the ground at the same time, then we know the hypothesis is false.

The approach will become clearer with an example that is not falsifiable:

   "There are other inhabited planets in the visible universe."

Here, the hypothesis starts differently with "There are others..." . It does not say how likely we are to find another inhabited planets. So, we could send thousands of probe in the universe and, even if they all returned with a negative answer, we would not be able to conclude that the hypothesis is false. It would be sufficient to change it a bit so that we can have a lower bound on the probability of finding an inhabited planet and it would become falsifiable.

Also, note that, if we were to use the "logically" style of argument, we could say that it is falsifiable because we can logically look at all the planets and check that they are not inhabited. We see that the feasibility to find a corroborating observation with a non negligible probability is an important ingredient in the falsifiability of a theory.

If we were to claim that the likeliness to find a corroborating observation is a fundamental and necessary part of falsifiability, it could be original research, because I am writing this from common sense. It might be there in the literature, but I haven't looked. Dominic Mayers (talk) 21:18, 4 November 2017 (UTC)

"The definition of falsifiability should primarily apply to a valid hypothesis or theory - that's the idea."

Why shouldnt it apply to every hypothesis? Why would that not, for example, apply to some nonsense I make up?

Also, how is any theory "valid"? Thats the whole point of a theory: Thats its not "the truth" and might at any point be proven wrong. Eheran (talk) 12:09, 23 January 2018 (UTC)

I did not say that it should only apply to valid theories. I only said that this is where the concept of falsifiability is most interesting. I could have said that it should at the least apply to valid theories, but it was stronger to say that these are the most interesting cases to consider. I maintain my point that the examples of falsifiable theories that are given should be valid theories. If the concept or the way to explain it does not work with valid theories, then there is a problem with the concept or the way to explain it. Dominic Mayers (talk)

Regarding the other point, which is that we don't know for sure that any theory is valid, it does not affect my line of reasoning. The point becomes, then, that the concept of falsifiability should also (and primarily) apply to the theories that we consider valid now. In fact, this is the key point. How could it be a good thing for a theory to be falsifiable, if that concept only makes sense when we know already that the theory is false. If it is a good thing, then it should be there also in the theories that we consider valid, for now. This is just basic common sense. Dominic Mayers (talk) 02:25, 8 March 2018 (UTC)

1. In The Logic of Scientific Discovery Popper himself used the example of white swans.
2. Still recently this causes doubts and perplexities, although scientists and epistemologists have long solved the problem by transforming the verification into corroboration through the statistical, probabilistic, Bayesian method.
3. Popper's approach can provoke some (apparent) logical paradoxes such as that of the black raven, but it too is solved by using Bayesian techniques.

--Mauro Lanari (talk) 15:21, 1 April 2018 (UTC)

I don't understand fully the references that you provided, but they seem to propose approaches based on probability, which is what I was arguing for. Well, great! Why is it that these are not mentioned in the article? Also, if the argument to support the white swan example is an historical one, then it should be presented that way. As it is now, it is presented as if it was the commonly accepted way, in the current state of knowledge, to explain the general concept of falsifiability. Dominic Mayers (talk) 00:24, 2 April 2018 (UTC)

As far as I could, I've already edited the article in such a direction. If you know how to do better, you are free to contribute. --Mauro Lanari (talk) 02:15, 2 April 2018 (UTC)

Just look at the overview. It is all about Popper. The example are those of Popper, etc. My feeling is that this is a great article, except that the title is wrong. It should be "Falsifiability as seen by Popper." Dominic Mayers (talk) 01:17, 3 April 2018 (UTC)

We do not make article titles of this type. If you have other authors who discuss falsifiability, please feel free to expand. Staszek Lem (talk) 00:48, 4 April 2018 (UTC)

Inspired by your comment, I went to see the article again. Your suggestion would be too much in opposition with the current structure of the article. There is even a large section on criticisms of Popper's view. Clearly, the entire article is built around Popper. The only reasonable way to contribute to this article is to go along with its current structure. I maintain, therefore, that it should be presented for what it is: an article on Popper's falsifiability. If I have to be bold, I would say that you are wrong when you say that the title should not be "Popper's falsification" or something along these lines. Dominic Mayers (talk) 14:59, 12 April 2018 (UTC)

No. We do not do this way. There is a topic called "Falsifiability" and wikipedia has article on this topic. Wikipedians are mostly amateurs and hobbyists; deficiency of subject experts as a long and well-known pain of Wikipedia. Therefore coverage of certain subjects is insufficient. In such situations the proper solution is improve subject coverage by expanding the article with views other than Popper's. Staszek Lem (talk) 16:32, 12 April 2018 (UTC)

Well, I am not bold enough to drastically change the structure of an article. What you suggest requires much more than adding new content. It requires that we change the overall structure of the article. In fact, a lot of content is already there, but it is presented in a structure where Popper's view is the central view. Moreover, it is questionable whether it makes sense to change the structure, because it is unclear how much the term falsifiability is in practice separated from Popper's view. I mean, falsification and Popper's falsification are not so far from being synonymous in people's mind. The purpose of changing the title would then be to better reflect that reality and makes sure people are not mislead. To be fair, it is not that much misleading, because it's very clear that it's about Popper's falsification. Only the title is misleading and perhaps the phrasing at the beginning. Dominic Mayers (talk) 17:03, 12 April 2018 (UTC)

Also, after I posted my comment, someone added an example of a true theory that is falsifiable. So, I feel my comment might have contributed to a useful modification. I would like to further comment that the examples of true theories that are falsifiable are all token of a generic type of theories, for which we have one token that is false. For example, All swans are either black or white is an instance of theories of type All swans are either X or Z where X and Z are colors. In this case, if I replace X and Z with yellow and blue, respectively, the theory is false. Another example is There is a planet between mercury and earth. This theory is true and falsifiable. But, it is also an instance of There is a planet between X and earth, where X is a planet, and if I replace X with Venus, the theory is false. This is an issue, in my opinion, because it suggests that if a theory cannot be seen as a token of a type that is some times false, then it is not a valid theory. For example, every people that can speak, can also think is a true theory. We can corroborate it by looking at EEG signal, etc. Maybe I am lacking imagination, but I cannot find a type for this theory that has a false instance. It is important that the testing procedure applies equally well to every instance of the type. This example involves human beings, but I suspect that we can find examples that do not involve human beings. Therefore, I still maintain that a more robust definition should involve probabilities, as I discuss above. Dominic Mayers (talk) 17:03, 12 April 2018 (UTC)

Here is another example. All the stars in the sky appear smaller than the moon. In this case, I can find a type with a false instance, but only if I modify the sentence to make it more precise: From earth, all the stars in the sky appear smaller than earth's moon. I could then have the type From X, all the stars in the sky appear smaller than earth's moon, where X is a planet. From X = Pluto, Betelgeuse apparent size is larger than earth's moon apparent size. It's not easy to find an example where we cannot find a type with a false instance. Dominic Mayers (talk) 18:14, 12 April 2018 (UTC)

The last example of a true theory was an instance of a type with a false instance, because its truth was relative to earth. In fact, this is also the case for All swans are either X or Z : its truth is relative to the colors X and Y. Consider E = mc^2. This is an instance of the type E = mc^n where n is a non-negative integer. The idea is that, if we modify the laws of a theory in such a way that the same testing procedures apply, we can check that the predictions would be false. Again, it is an instance of a type with a false instance. It's really not easy to find a counter-example. Dominic Mayers (talk) 18:40, 12 April 2018 (UTC)

Sorry, Wikipedia is not a place for original thought. You are fairly new to Wikipedia, as I see, therefore please stop right here and read a couple of our fundamental rules about article content: verifiability, reliable sources, citing sources, and no original research. If you really want to contribute to Wikipedia, until you start grasping our home rules, do it in small steps: if you see something missing in Wikipedia, grab a book or a good scholarly article on the subject, and summarize the missing part into Wikipedia, and don't forget to cite the source, i.e., do not do it just out of your head. Staszek Lem (talk) 20:03, 12 April 2018 (UTC)

I know what is an encyclopedia. So it was obvious to me that I could not add this in the article. BUT, before you can look up well established knowledge for an encyclopedia, you need to do some thinking. Otherwise, you will not even know what you are looking for. In this manner, as far as I can see, my comments helped improve the article. Now, there is an example of a true theory that is falsifiable. There was none before. Dominic Mayers (talk) 23:17, 12 April 2018 (UTC)

But I do feel that this discussion about a falsifiable theory always being an instance of a type with a false instance is not so much related to the key point that is very much relevant here, which is that this article will most likely always remain an article about Popper's falsifiability. Therefore, the title and the few sentences that suggest otherwise are misleading. Dominic Mayers (talk) 23:28, 12 April 2018 (UTC)

OK. OK. Let me approach from the other end. Who else introduced the concept of falsifiability besides Popper and which is different from Popper's? Staszek Lem (talk) 23:49, 12 April 2018 (UTC)

Sorry, I was not ignoring you on purpose. I did not see your reply. I am ignorant about the history, but the term "falsifiability" have been introduced by Popper. I suspect that if we only report knowledge written with that terminology, Popper will always be the reference. Given that it will be difficult to report knowledge written with a different terminology without doing some interpretation, this is another reason why I strongly believe that this article is doomed to remain about Popper's falsification. Dominic Mayers (talk) 00:09, 13 April 2018 (UTC)

If your feeling is that the article should be extended, then the only easy way I see to extend it without fighting against the structure is to consider the entire Popper's scientific method, in which falsification is only an ingredient. Dominic Mayers (talk) 00:19, 13 April 2018 (UTC)

I will not pursue this further, because I am afraid that perhaps the rule is that talk pages are not the place to think together about the subject, even if this could help look up well established knowledge useful to the article, which is far from easy, because there is a lot of well established knowledge. I will just end by saying that my second example above (at the top of this section) was not a counter example:

   "Any two objects dropped from the same height above the surface of the earth will hit the ground at the same time, as long as air resistance is not a factor."

The type that contains this sentence is

   "Any two objects dropped from the same height above the surface of the earth will hit the ground at times less than Max and more than Min seconds apart, as long as air resistance is not a factor."

So, I start to feel that this is a valid criteria. In fact, it seems equivalent to the predictive value of the theory. The theory must select some valid instances among a set of instances, which I call the type. This gives me some idea what I should look for to have a better article. It would still remain an article about Popper's falsification, but it would be an improvement to the section criticism. Dominic Mayers (talk) 23:45, 12 April 2018 (UTC)

This entire section can be ignored. Dominic Mayers (talk) 19:37, 9 June 2018 (UTC)

Logical refutation is not useful in the definition of falsifiability, only confusing.

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In Logic of Scientific Discovery (LofSD), we have

   Besides being consistent, an empirical system should satisfy a further condition: it must be falsifiable.

and note that logical refutation (i.e., not based on observations) is not possible in the context where the theory is consistent. Moreover, consider the definition of falsifiability from LofSD:

   A theory is to be called ‘empirical’ or ‘falsifiable’ if it divides the class of all possible basic statements unambiguously into the following two non-empty subclasses. First, the class of all those basic statements with which it is inconsistent (or which it rules out, or prohibits): we call this the class of the potential falsifiers of the theory; and secondly, the class of those basic statements which it does not contradict (or which it ‘permits’). We can put this more briefly by saying: a theory is falsifiable if the class of its potential falsifiers is not empty.

The first sentence says that the two classes must be non-empty. The last sentence only requires that the class of potential falsifiers is non-empty. There is no ambiguity if the other class is always non-empty, but this excludes logically refutable theories from the definition. What is clear is that logical refutation is not needed in the definition. In fact, it only creates confusion, because the essence of the definition is in the relation between the statement of the theory and the set of possible basic statements, which by their definition in LofSD are open to observations. Dominic Mayers (talk) 19:55, 18 April 2018 (UTC)

This is OK now. Dominic Mayers (talk) 19:38, 9 June 2018 (UTC)

Missing reference for The concern with falsifiability gained attention

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The sentence The concern with falsifiability gained attention ... does not make sense unless falsifiability was previously defined by other authors. However, this is not obvious at all, because falsifiability is a subtle concept that is part of a larger mechanism that involves also falsification and then feedbacks to suggest the creation of a new theory. Falsifiability is a very specific property (see previous section) that must be respected so that falsification is then possible. It should be noticed that the two previous paragraphs refer to Popper's definition. We cannot improvise a new definition of falsifiability or start to mix together under the concept of falsifiability different definitions that are vaguely related. Therefore, if falsifiability was previously defined in a way that is equivalent to Popper's definition, references must be provided. Unless references are provided, this sentence should be removed or totally rephrased, because otherwise it implies something that is most likely wrong. It would not be enough that one author makes a similar statement without himself providing references that show that falsifiability was defined before. Dominic Mayers (talk) 13:21, 20 April 2018 (UTC)

This is OK now. Dominic Mayers (talk) 19:39, 9 June 2018 (UTC)

About the contemporary philosophers section: the opinion of Bartley III

Even within an article about Popper, I would not understand that we include this quote of W. W. Bartley III:

Sir Karl Popper is not really a participant in the contemporary professional philosophical dialogue; quite the contrary, he has ruined that dialogue. If he is on the right track, then the majority of professional philosophers the world over have wasted or are wasting their intellectual careers. The gulf between Popper's way of doing philosophy and that of the bulk of contemporary professional philosophers is as great as that between astronomy and astrology."

— W. W. Bartley in Philosophia 6 1976

It's taken out of context. Even in the section about Popper in the Bartley III article, we don't see that kind of text. The text used is much more neutral and informative, though not about falsifiability. I don't see how we can justify such a text here. Dominic Mayers (talk) 18:48, 10 June 2018 (UTC)

"All swans are white" to illustrate the problem of induction is not from Popper.

The philosopher John Stuart Mill, writing in A System of Logic in 1843, used the statement "all swans are white" to show how large numbers of consistent observations can encourage a wrong induction. Karl Popper used the “black swan fallacy” to show that scientific ideas can never be proven true, only falsified. Bertrand Russell was yet another leading philosopher to invoke black swans in this way, in his 1912 book The Problems of Philosophy.
— Tim Low in Australian Geographic July 2016

It's not that important. Popper never claimed that the problem of induction was not known before him. But it is interesting to know. It explains why Popper used this example, despite the fact that it is far from being the best example to illustrate falsifiability. Dominic Mayers (talk) 01:02, 15 June 2018 (UTC)

Avoiding confusion with the ordinary notion of falsifiability in the lead section.

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Currently, there is nothing in the lead section to provide some idea about the difference between Popper's falsifiability and ordinary common sense falsifiability. It's good not to be too technical in the lead, but not at the cost of a possible confusion. The term "logical" should perhaps be added to qualify the falsification. It's delicate, because we want to emphasize also that the falsification should be through observation, that is, it should be empirical. One might be confused and ask how could it be at the same time logical and empirical? The answer is simple, the statements of the theory, including the basic statements (i.e., the potential falsifiers) and the refutation must be logical, i.e.,formal, but the falsifiers must be interpretable in terms of observations, they must be empirically testable. There is no clean definition of empirically testable (in the context of basic statements) - it is a question of convention, of agreement between scientists. Because, empirically testable is on purpose left undefined, we cannot say that the theory can be empirically refuted. It would make no sense to say that. The falsifiability criterion is only that it can be logically refuted given the logical form of the theory. We must find a way to give some clue of this concept, without being too technical. Dominic Mayers (talk) 20:44, 13 June 2018 (UTC)

I made some edits, but I had to undo all of them - it did not work. Popper's definition is subtle. Dominic Mayers (talk) 00:56, 14 June 2018 (UTC)

Here is the new version that I propose:

A statement, hypothesis, or theory has falsifiability (or is falsifiable) if there exists a reproducible basic statement that contradicts it. For example, the claim "all swans are white" is falsifiable since the basic statement "In 1697 the Dutch explorer Willem de Vlamingh saw a black swans in Australia" contradicts it and is reproducible (other persons at other times and locations can see a black swan). The concept is also known by the terms refutable and refutability.

The requirement for reproducibility is not formally correct, but it is a compromise. The correct formal requirement is that the basic statement must belong to a class of statements with date, location and subject parameters (and perhaps other parameters). In this example, the parameters are date=1697, subject=Dutch explorer Willem de Vlamingh and location=Australia. The key point is that falsifiability has two disctinct parts. The formal or logical part has nothing to do with actual observations - this part is purely logical or formal. The observational component is not formal and depends upon conventions, agreement between the scientists. Because of this second component, Popper explains that falsifiability does not mean that it can be (empirically) proven false. Dominic Mayers (talk) 01:42, 15 June 2018 (UTC)

It's even more complicated than that. As a criterion of demarcation, falsifiability does not require that the basic statement (the falsifier) is reproducible (a part of a class). It only requires that the class of falsifiers is not empty. However, Popper adds:

"We say that a theory is falsified only if we have accepted basic statements which contradict it (cf. section 11, rule 2). This condition is necessary, but not sufficient; for we have seen that non-reproducible single occurrences are of no significance to science. Thus a few stray basic statements contradicting a theory will hardly induce us to reject it as falsified. We shall take it as falsified only if we discover a reproducible effect which refutes the theory. In other words, we only accept the falsification if a low-level empirical hypothesis which describes such an effect is proposed and corroborated. This kind of hypothesis may be called a falsifying hypothesis.

— Karl Popper, The Logic of Scientific Discovery, p.66

In other words, the criterion for demarcation is only that a falsifier exists, but in practice, this is very far from allowing falsification. I am not sure why Popper did not add reproducibility as part of falsifiability. Perhaps, formally, if we care only about a demarcation criterion, it does not matter. Anyway, it makes it even more clear that falsifiability is only a demarcation criterion - it does not mean at all "capable of being proven false".

It will remove the "reproducible" from the text and mention in a footnote that reproducibility is necessary if the theory is to have a chance to be falsified and add the above quote from Popper in this footnote. Dominic Mayers (talk) 02:19, 15 June 2018 (UTC)

This has been taken care of now Dominic Mayers (talk) 04:03, 15 June 2018 (UTC)

References

He [Popper] saw falsifiability as the criterion for demarcating the limits of scientific inquiry.

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In the lead, we have the statement.

   He saw falsifiability as the criterion for demarcating the limits of scientific inquiry.

This is not true. Popper made a clear distinction between the process of falsification (which is defined in falsificationism) and falsifiability. He saw the latter as the demarcation criteria between empirical statements and non empirical statements. This takes care of what kind of statements should be proposed, but a scientific inquiry method must also determine how they will be rejected. In particular, Popper was aware that we will not replace a theory, even if it is contradicted by observations, until we have a "better" theory. So, falsificationism goes way beyond falsifiability. Falsifiability is not about the scientific method as a whole. It is simply a criteria used to separate scientifific (or empirical) statements from non empirical statements. Dominic Mayers (talk) 18:47, 21 May 2018 (UTC)

To put it in another way, Popper was aware of the two meanings of the expressions "falsifiable" and "falsifiability".

We must distinguish two meanings of the expressions "falsifiable" and "falsifiability":

1) "Falsifiable" as a logical-technical term, in the sense of the demarcation criterion of falsifiability. This purely logical concept — falsifiable in principle, one might say — rests on a logical relation between the theory in question and the class of basic statements (or the potential falsifiers described by them).
2) "Falsifiable" in the sense that the theory in question can definitively or conclusively or demonstrably be falsified ("demonstrably falsifiable").

I have always stressed that even a theory which is obviously falsifiable in the first sense is never falsifiable in this second sense. (For this reason I have used the expression "falsifiable" as a rule only in the first, technical sense. In the second sense, I have as a rule spoken not of "falsifiability" but rather of "falsification" and of its problems) -- Popper, Karl. Realism and the Aim of Science p.XII.

The emphasis is mine. The key point is that Popper was aware that of the problem of falsification and he explained that this other meaning of falsifiability is not achievable. Dominic Mayers (talk) 23:56, 21 May 2018 (UTC)

Here is another quote from Popper:

"But when is a statement falsifiable? It is of great importance to current discussion to notice that falsifiability in the sense of my demarcation criterion is a purely logical affair. It has to do only with the logical structure of statements and of classes of statements. And it has nothing to do with the question whether or not certain possible experimental results would be accepted as falsifications."

— Karl Popper, Popper, Karl (1983). Realism and the Aim of Science: From the Postscript to The Logic of Scientific Discovery (2013 ed.). London and New York: Routledge. ISBN 0-415-08400-8. {{cite book}}: Invalid |ref=harv (help) p. XX.

The process by which a falsifier is accepted as a falsification is complex. This is not covered at all in the current article. I feel that something should be written about it. Dominic Mayers (talk) 16:20, 28 May 2018 (UTC)

This has been taken care of now Dominic Mayers (talk) 04:11, 15 June 2018 (UTC)

Example from Popper of a falsifiable theory that has not been and would not be falsified so soon

"Einstein’s principle of proportionality of inert and (passively) heavy mass. This equivalence principle conflicts with many potential falsifiers: events whose observation is logically possible. Yet despite all attempts (the experiments by Eötvös, more recently refined by Dicke) to realize such a falsification experimentally, the experiments have so far corroborated the principle of equivalence."

— Karl Popper, Popper, Karl (1983). Realism and the Aim of Science: From the Postscript to The Logic of Scientific Discovery (2013 ed.). London and New York: Routledge. ISBN 0-415-08400-8. {{cite book}}: Invalid |ref=harv (help) p.XX

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This raises a natural question. What do we mean by "logically possible". Why does Popper feel that an observation that contradicts such a fundamental law can be "logically possible", but an observation that contradicts "All human actions are egotistic, motivated by self-interest.", which is an example from Popper of a non falsifiable statement, is not logically possible. I never seen feel a clean and precise answer to that question.

I suspect that whether a falsifier is logically possible depends on the background theory, the theory that determines what is a measurement or observation, etc. but not whether the new theory is false or true. If the background theory would allow observations from which, by definition, we can infer that an action is not egotistic, then the statement "All human actions are egotistic." would be falsifiable. So, it is relative to a background theory.

The answer is the logically means that formal basic statements that contradicts the theory exists and, if we ignore the theory, they are possible. The theory, by its predictive power, contradicts these basic statements. Dominic Mayers (talk) 04:17, 15 June 2018 (UTC)

Dominic Mayers (talk) 16:34, 28 May 2018 (UTC)

Moving the section Comtemporary philosophers section in the Popper article

The section Comtemporary philosophers is definitively not enlightening at all on the issues of falsifiability. It's about Popper himself and his overall philosophy of science. It contains little if anything about falsifiability. Therefore, it should be merged in the Karl Popper article, if the subject is not already well covered there. Dominic Mayers (talk) 15:33, 29 May 2018 (UTC)

Some of the content could be reused. ( See the other section below). In any case, it's good to know about these "contemporary" philosophers - they might have said something about falsifiability. BTW, the term "contemporary" is a bit funny here. Since Popper is almost a contemporary philosophers, these "contemporary" philosophers were perhaps more contemporary to Popper than they are contemporary to the young generation of philosophers today. Dominic Mayers (talk) 03:19, 16 June 2018 (UTC)

Mismatch between the title for the section "Naive Falsificationism" and its content.

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It seems that there is a big confusion about what is "naive falsificationism", but I don't want to go into this. What is clear is the content of the section "naive falsificationism" is actually about falsifiability, not about falsification or falsificationism. Let me recall how much Popper stressed that we should not confuse falsifiability and falsification. The former is defined only in terms of the relation between statements, without direct reference to observations or experiments - it is a purely logical concept, whereas falsification can only occur when we confront statements with actual observations. All the subsections in "naive falsificationism" are at this logical level. Whoever thoughts that this was about falsification or naive falsificationism had no understanding of falsification. Dominic Mayers (talk) 15:51, 16 June 2018 (UTC)

This is taken care of now. Dominic Mayers (talk) 15:15, 17 June 2018 (UTC)

The terms observational and categorical in titles are not used in the text

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Normally, when we use a technical term in the title of a section, we expect the term to be defined within the section or before the section. One section in entitled "Two types of statements: observational and categorical", yet the terms observational or categorical are not defined in the section or before it, in fact, they only appear in the entire article in titles and in the expression "observational data". This makes the article more difficult to follow, because, though the notion of categorical statements is well known in philosophy, it is not so well known for a general audience. Moreover, it is not used much in the context of falsifiability in the literature. In particular, Popper did not use it when he explained the different kinds of statements. He mentions basic statements, empirical statements, singular statements, universal statements, but not categorical statements. We have the same situation with the section "Inductive categorical inference". I suggest that we use better titles for these sections. I have no title yet to propose. I want to review carefully the sections, the references provided, etc., before I consider new titles. By the way, these sections look interesting and important to explain falsifiability. Dominic Mayers (talk) 18:36, 13 June 2018 (UTC)

This is taken care of now. Dominic Mayers (talk) 15:16, 17 June 2018 (UTC)

Two types of statements: observational and categorical

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I already mentioned that "observational" and "categorical" should be defined before the title or in the section that has this title. Here I consider the section itself. It does not use the same definitions as Popper. I think it's better to use one set of definitions and it's natural to use Popper's definitions, given that falsifiability was defined by Popper.

For example, the section says ... such as "there is a white swan". Logicians call these statements singular existential statements, since they assert the existence of some particular thing. This is not consistent with Popper's definition. In accordance with Popper's definition, a singular statement must contain an individual concept or mention a specific space-time location. So, "there is a white swan in Africa" is a singular existential statement, but "there is a white swan" by itself is not a singular existential statement. It is, instead, a good example of a strict or pure existential statement. I propose to revise this section so that it is consistent with Popper's definition. Dominic Mayers (talk) 02:56, 16 June 2018 (UTC)

This is taken care of now. Dominic Mayers (talk) 15:16, 17 June 2018 (UTC)

The section Inductive categorical inference

Again, the term "categorical" is not used at all in the article, not even in the section. We will have to change the title. The notion of (logical) inference is indeed central in the notion of falsifiability, but the current content of the section fails to convey it. It is central, because in the definition of falsifiability, the notion of "truth" in the sense of conform with observational facts is separated from the notion of provability through rules of inference. Popper considers that the notion of truth is thus not accessible to formal logic and is not a part of the logic of scientific discovery. I am not claiming that Popper has the correct approach, but if we present Popper's definition of falsifiability the distinction between provability through rules of inference, purely logical manipulation, and the notion of validity or truth because of corroboration with experiments and observations must be clear. Popper's definition of falsifiability is only in terms of logical relations and formal deductions and a connection with experiments and observations that must be confined in the background knowledge or can be seen as influencing the metaphysical process that leads to conjectures. In between the background knowledge and the metaphysical process that leads to conjectural theories, we have the logic of scientific discovery. In other words, in "The Logic of Scientific Discovery", the term "Logic" means the "formal logic". Dominic Mayers (talk) 16:54, 17 June 2018 (UTC)

The subsection Deductive falsification, about modus tollens

This subsection is incorrect in two fundamental ways. First, modus tollens is a logical inference rule. A very fundamental aspect of inference rules in logic is that they stand by themselves without any reference to an observation. Second, Popper is very clear that refutation requires more than a contradiction with a single basic statement. This is a point that Popper emphasized a lot: "We must clearly distinguish between falsifiability and falsification. ... As to falsification, special rules [beyond modus tollens] must be introduced ", " ... two meanings of the expressions falsifiability and falsifiable ...", "We say that a theory is falsified only if we have accepted basic statements which contradict it (cf. section 11, rule 2). This condition is necessary, but not sufficient; for we have seen that non-reproducible single occurrences are of no significance to science." etc.

One could use modus tollens with a basic statement that is directly interpretable as an experiment - in which case the basic statement can be seen as a protocol sentence, but even then Popper refuses that we interpret basic statements as protocol sentences. It is correct to say that we can infer that a theory (a strict universal statement) is false using modus tollens with a basic statement - this is pure logic, a fundamental part of the falsifiability concept, which is also emphasized by Popper, but this is NOT falsification. Dominic Mayers (talk) 15:42, 18 June 2018 (UTC)

Section Naïve falsification - mismatch with definition found in the literature.

The content of this section is interesting. It's not about falsifiability as such, it is about falsification and the rules of the game for choice of theories, etc., but I suppose that it is ok, perhaps necessary, to put falsifiability in this context. However, we have to respect the definitions used in the literature and "naive falsification" in the section is not defined and what is written conflicts with what is easily found in the literature. There are very few references given, in fact only one for 4 large paragraphs. So, I cannot tell where the definitiojuns can be found.

In https://en.wiktionary.org/wiki/naive_falsificationism , http://www.oxfordreference.com/view/10.1093/oi/authority.20110803100221651 , https://www.youtube.com/watch?v=LQjoHKUVHPw the definition of naive falsificationism is that a single observation is enough to refute an hypothesis. However, in some cases, they also add that this single instance is enough to refute the entire claim. There are two things here: whether a single observation is enough and whether it refutes the entire claim or only a part of it, and we cannot tell which part.

In https://rationalwiki.org/wiki/Falsifiability and https://sites.google.com/site/drtimthornton/courses/the-philosophy-of-science/sophisticated-methodological-falisficationism/remarks-on-sophisticated-methodological-falsificationism , the emphasis is on the fact that a refuted statement has many parts, including initial conditions and the background knowledge, and naive falsification ignores this aspect. However, in the first case, naive falsificationism is considered equivalent to Popperian falsificationism, whereas in the second case, it is only said that Popper was aware of the distinction. Of course, the second view is correct.

Anyway, it is very unclear which view point is presented in this section, because we have very little references and the terms naive falsificationism is not clearly defined. More importantly, we should keep in mind that this article is about falsifiability, not falsification, so we should make sure that we present falsification only to provide the context - we must not lose the focus. — Preceding unsigned comment added by Dominic Mayers (talk • contribs) 23:29, 18 June 2018 (UTC)

Use of Modus Tollens

The article referred to modus tollens for a simple contradiction between two statements. This is not the way modus tollens works, there must be some derivation (or an implication), and it is not in that context that Popper mentions it:

"The falsifying mode of inference here referred to—the way in which the falsification of a conclusion entails the falsification of the system from which it is derived—is the modus tollens of classical logic. It may be described as follows: Let p be a conclusion of a system t of statements which may consist of theories and initial conditions ..."

— Karl Popper, The Logic of Scientific Discovery, p.55

Then, if the conclusion is falsified, the rule says that the hypothesis used in the derivation (or the antecedent in the implication) is also falsified. Dominic Mayers (talk) 01:14, 20 June 2018 (UTC)

The section Criticism contains anything but criticisms of Popper's falsifiability

Let's consider the subsections.

Contemporary Philosophers

I already mentioned that its subsection Contemporary Philosophers is not at all about falsifiabilility. I can add that the paragraph about David Miller perspective is not at all a criticism. Dominic Mayers (talk) 15:57, 20 June 2018 (UTC)

Kuhn and Lakatos

The next subsection about Kuhn and Lakatos is not a criticism. It says that Kuhn's work was seen by some as a vindication of Popper's falsificationism and that Lakatos was foremost amongst these:

Some falsificationists saw Kuhn's work as a vindication, since it provided historical evidence that science progressed by rejecting inadequate theories, and that it is the decision, on the part of the scientist, to accept or reject a theory that is the crucial element of falsificationism. Foremost amongst these was Imre Lakatos.

Also, the last two sentences are not about falsifiability and they are placed out of context.

Whereas Popper rejected the use of ad hoc hypotheses as unscientific, Lakatos accepted their place in the development of new theories

The context is that Lakatos, as do other philosophers, did not separate the logical part of the demarcation criterion from its methodological part. Here is a quote from Lakatos that illustrates this.

"Now if we apply this quasi-empirical meta-criterion (which I am going to reject later), Popper's demarcation criterion - that is, Popper's rules of the game of science - has to be rejected.'"

— Imre Lakatos, The methodology of scientific research Programmes, Philosophical Papers, Volume I, p.126

This is an important point, because, for Popper, there was only the logical part: the demarcation criterion, which he calls falsifiability, had to be only in terms of the logical form of the theory. Popper would not accept a methodological aspect in the demarcation criterion, because it could not, in his view, be made rigorous. However, nevertheless, Popper agreed that this methodological aspect was nevertheless necessary, but it had to be kept separated.

The point is that the context is so important. Usually, when Popper says that something is not scientific, he means that it is not (logically) falsifiable. Perhaps, Lakatos refers to something else, i.e., to the fact that, if whenever the theory is to be falsified, we modify it with an ad hoc hypothesis, then it cannot be falsified. This has nothing to do with the (logical) falsifiability criterion - it is about a methodological criterion. The point is that even a perfectly fine logically falsifiable (thus scientific) theory cannot be methodologically falsified, if we redefine it as needed so that it remains valid. It's not the (logical) criterion that does not work. It's the method, how we use it. So, it's not a critic of the logical criterion.

It remains a fact that, as far as the methodological aspect is concerned, Popper was against ad hoc hypotheses that prevent the actual falsification. However, given that the methodology part was not seen as rigorous by Popper, he explained that there are exceptions. It could be that Lakatos found an exception that was not considered by Popper, but we enter into small details here, which should not be given undue weight. Before, we present such a detail, we need to present the big picture. Dominic Mayers (talk) 15:57, 20 June 2018 (UTC)

Feyerabend

This is so weird. The whole subsection is about how Feyerabend disagreed with Lakatos. Given that Feyerabend was a strong advocate of Popper's view, it is weird that the focus is on Lakatos. I am not saying that the view of Feyerabend on Popper should even be mentioned, because this is not an article about Popper, but it is so weird that we present his view on Lakatos. Dominic Mayers (talk) 15:57, 20 June 2018 (UTC)

The term 'Metaphysical Research Program' is not used properly.

I noticed that the term 'metaphysical research program' is not used properly. Here is what Popper wrote about it.

"In science, problem situations are the result, as a rule, of three factors. One is the discovery of an inconsistency within the ruling theory. A second is the discovery of an inconsistency between theory and experiment – the experimental falsification of the theory. The third, and perhaps the most important one, is the relation between the theory and what may be called the 'metaphysical research programme'.

By raising the problems of explanation which the theory is designed to solve, the metaphysical research programme makes it possible to judge the success of the theory as an explanation. On the other hand, the critical discussion of the theory and its results may lead to a change in the research programme (usually an unconscious change, as the programme is often held unconsciously, and taken for granted), or to its replacement by another programme. These programmes are only occasionally discussed as such: more often, they are implicit in the theories and in the attitudes and judgements of the scientists.

I call these research programmes 'metaphysical' also because they result from general views of the structure of the world and, at the same time, from general views of the problem situation in physical cosmology. I call them 'research programmes' because they incorporate, together with a view of what the most pressing problems are, a general idea of what a satisfactory solution of these problems would look like."

— Karl Popper, Quantum Theory and the Schism in Physics, p.161

In the article, we say that every thing metaphysical is part of this. This is not true. In fact, it should be obvious from the usual definition of 'program'. Dominic Mayers (talk) 20:08, 22 June 2018 (UTC)

Case of DNS records

Would it be an improvement to the article to have an example of the level of integrity of DNS records? I have a case that could demonstrate a subset of falsifiability (false-flag spam lists and unique changes to the DNS of hydro.net from 1996 to 2016). 126etc126.209.32.199 (talk) 13:31, 15 August 2018 (UTC)

My impression would be that this would best belong in a DNS related article. However, even then, to avoid original research, a source should have made that constatation which could then be cited and summarized there. Thanks, —PaleoNeonate – 21:22, 15 August 2018 (UTC)

Regarding the added "... or observation": clarifying the empirical status of basic statements

User:James343e added "or observation" after "basic statement" in the definition of the falsifiability criterion, see https://en.wikipedia.org/w/index.php?title=Falsifiability&diff=prev&oldid=850864548. I am not surprised. One difficulty in understanding Popper's falsifiability criterion is that it is a purely logical criterion, in the following sense that it is only stated in terms of statements and their relation, not in terms of perceptions or observations, and yet it must have an empirical character. Regarding this issue, Popper wrote:

Perceptual experiences have often been regarded as providing a kind of justification for basic statements. It was held that these statements are ‘based upon’ these experiences; that their truth becomes ‘manifest by inspection’ through these experiences; or that it is made ‘evident’ by these experiences, etc. All these expressions exhibit the perfectly sound tendency to emphasize the close connection between basic statements and our perceptual experiences. Yet it was also rightly felt that statements can be logically justified only by statements. Thus the connection between the perceptions and the statements remained obscure, and was described by correspondingly obscure expressions which elucidated nothing, but slurred over the difficulties or, at best, adumbrated them through metaphors.

Noting that basic statements are singular existential statements with an empirical character, we can see that Popper recognizes that his approach faces the same dilemma:

If falsifiability is to be at all applicable as a criterion of demarcation, then singular statements must be available which can serve as premises in falsifying inferences. Our criterion therefore appears only to shift the problem—to lead us back from the question of the empirical character of theories to the question of the empirical character of singular statements.

However, Popper was very pragmatic in his approach and noted that, in practice, it was a false problem:

Yet even so, something has been gained. For in the practice of scientific research, demarcation is sometimes of immediate urgency in connection with theoretical systems, whereas in connection with singular statements, doubt as to their empirical character rarely arises. It is true that errors of observation occur and that they give rise to false singular statements, but the scientist scarcely ever has occasion to describe a singular statement as non-empirical or metaphysical.

Therefore, Popper shifted his attention to a more serious problem, the problem of induction and expressed a solution on the basis of his purely logical demarcation criterion. His solution is simply that we only try to deduce from the falsifiable theory (and initial conditions) a statement that is contradicted by a basic statement, that is, we only try to falsify a theory, we never prove it.

He was also very much aware that his logical demarcation criterion for theories had to be complemented by a proper scientific methodology to create, reject, modify these theories, but he was very clear that this other part could hardly be made rigorous:

The requirement of falsifiability which was a little vague to start with has now been split into two parts. The first, the methodological postulate (cf. section 20), can hardly be made quite precise. The second, the logical criterion, is quite definite as soon as it is clear which statements are to be called ‘basic’ (cf. section 28).

This quote is a rare occasion where Popper mentions a methodological part to the requirement of falsifiability, but note that he does not say "a methodological part to the falsifiability criterion". He would not, because a "criterion" presumes some rigor, which the methodological part cannot have. More importantly, no confusion is possible given the context, because the methodological part is a requirement on the method, not on the theory itself: whenever we speak of a criterion for theories or statements, then we speak of the logical demarcation criterion given in terms of statements, basic statements, etc., not observations, etc. It could not have been otherwise.

Therefore, the addition of "or observations" is not helping to clarify the concept. Yet, it is clear that we need to clarify early the empirical status of basic statements, which was the basic intention behind the extra "or observation". We have to think about the best way to do that.--Dominic Mayers (talk) 02:07, 21 August 2018 (UTC)

So, one might ask why does Popper refer to observation in the following quote (see https://en.wikipedia.org/wiki/Falsifiability#cite_note-observation-1):

Einstein's principle of proportionality of inert and (passively) heavy mass. This equivalence principle conflicts with many potential falsifiers: events whose observation is logically possible. Yet despite all attempts (the experiments by Eötvös, more recently refined by Rickle) to realize such a falsification experimentally, the experiments have so far corroborated the principle of equivalence.
— Popper 1983 p. XX

The answer is that Popper wants to explain that falsifiability is different from falsification. To do that, Popper gives an example of a theory that is falsifiable even when its falsification has failed and seems to be doomed to always fail. In these attempts at falsification, a basic statement, which Popper also calls a potential falsifier, must be interpreted as an observation. So, this quote, when placed in its context, is perfectly consistent with the understanding that falsifiability, unlike falsification, is a purely logical affair. In fact, in the same page where this quote is found, Popper explains:

But when is a statement falsifiable? It is of great importance to current discussion to notice that falsifiability in the sense of my demarcation criterion is a purely logical affair. It has to do only with the logical structure of statements and of classes of statements. And it has nothing to do with the question whether or not certain possible experimental results would be accepted as falsifications.
— Popper 1983 p. XX

--Dominic Mayers (talk) 04:00, 21 August 2018 (UTC)

And rejected logical inconsistency as a criterion for falsification

The contributions by Dominic Mayers are certainly great and I am really thankful to her giant effort to improve the page. Nonetheless, I deleted a sentence because it is not clear for the general reader what does it mean. Dominic Mayers initially wrote:

"Popper clearly distinguished between falsifiability and falsification,[6] and rejected logical inconsistency as a criteria for falsification, because he considered consistency a prerequisite so necessary that it had to be a part of falsifiability, the (logical) demarcation criterion itself, not of a subsequent falsification."

What does "rejected logical inconsistecy as a criterion for falsification" means? The Wikipedia page where "logical inconsistency" redirects says that a consistent theory is one which does not contain contradiction. And the Wikipedia page for "contradiction" says that "In classical logic, a contradiction consists of a logical incompatibility between two or more propositions. It occurs when the propositions, taken together, yield two conclusions which form the logical, usually opposite inversions of each other. Illustrating a general tendency in applied logic, Aristotle's law of noncontradiction states that One cannot say of something that it is and that it is not in the same respect and at the same time."

Does it mean that Popper didn't consider contradictory (or incompatible) observations to be a criterion for falsification? Because that is not correct. The experiments of Pasteour falsified the spontaneous generation theory precisely because they represented a contradictory observation against spontaneous generation. The hypothesis that chimpanzees are herbivores (widely held in the 1950s) was falsified by Jane Goodall contradictory observations of wild chimpanzees hunting and eating monkeys.

Which page of which book does Popper say "I reject logical inconsistecy as a criteria for falsification"? That claim needs a source where Popper explicity says so.

I revised the page 72 of his Logic of Scientific discovery: http://strangebeautiful.com/other-texts/popper-logic-scientific-discovery.pdf

Popper doesn't say that "I reject logical consistency as a criterion for falsification" in any moment. He says that any system must be consistent since:

    the importance of the requirement of consistency will be appreciated if one realizes that a self-contradictory system is uninformative. It 
    is so because any conclusion we please can be derived from it. Thus no statement is singled out, either as incompatible or as derivable, 
    since all are derivable."

Thus, only unfalsifiable systems are inconsistent. Falsifiable systems are consistent according to Popper. Then Popper argues that

   A consistent system, on the other hand, divides the set of all possible statements into two: those which it contradicts and those with
   which it is compatible. (Among the latter are the conclusions which can be derived from it.)".

The problem is that Popper is defining consistency in a diferent manner than Wikipedia. According to Popper, a consitent system allows both contradictory and compatible statements.

But according to Wikipedia consistency is the property of a theory which does not contain contradiction: https://en.wikipedia.org/wiki/Consistency

And Wikipedia defines contradiction as the property of having two propositions which express the opposite: https://en.wikipedia.org/wiki/Contradiction

But according to Popper, a consistent system must allow both contradictory and compatible statements. On the other hand, according to Wikipedia, a consistent system cannot allow any contradiction or contradictory statement.

Since the Wikipedia definition of consistency differs from that of Popper, I think it is better to avoid putting the sentence "Popper rejected logical consistency as a criterion for falsifiability" and the whole paragraph that includes it. If such a paragraph were included, then it would be necessary to clarify in the lead section of the article what does Popper mean by logical inconsistency and consistency. Otherwise, such a messy paragraph should be excluded. (James343e (talk) 16:55, 28 August 2018‎ (UTC)

Thank you for the comment. I am sure that this paragraph could be improved. I did not write it alone, by the way. The decision to mention explicitly in the lead of the article that logical consistency is so important to Popper that it should precede falsification is not mine. I agree with this decision, but it is not mine. I like it, because it brings out that falsification is specifically about a contradiction against observations and thus goes beyond the purely formal or logical structure where the theory lies.

How do you propose that we convey the point that in Popper's definition falsifiable theories must be logically consistent? I see from your comment that you understand this point. We cannot change Popper's definition. If other philosophers have other definitions, we should mention them, but we must faithfully present Popper's definition. So, how should we convey this point.

Again, it was not my decision to explicitly mention this point. Originally, I only brought it as a footnote but someone felt it should be directly in the text.

Perhaps it could help to understand that it is natural that a logical system or language allows contradictory statements. The fact that in Popper's definition a consistent theory must exist together with statements that contradict it is not special at all. It certainly does not mean that Popper has a different notion of consistency. --Dominic Mayers (talk) 21:46, 28 August 2018 (UTC)

And let me answer your questions: What does "rejected logical inconsistecy as a criterion for falsification" means? ... Does it mean that Popper didn't consider contradictory (or incompatible) observations to be a criterion for falsification? The answer is that there is an implicit "internal" before "logical inconsistency". When we say that a theory is inconsistent, we usually mean "internally inconsistent". For every statement, there is always another statement that contradicts it, because we can simply add a "Not" before. We know that not every statement is inconsistent, of course. So, clearly, inconsistent usually refers to an internal inconsistency. A theory corresponds to a set of statements that can be derived from it. We can equate the theory with this set of statements. The theory is consistent, if they do not contradict each other. The existence of contradictory statements (not internal to the theory) is not interesting, because these contradictory statements always exist. However, Popper's definition is that among these contradictory statements, we must have basic statements. We see how important is the concept of basic statements. They must be existential singular statements that can be interpreted as observations. --Dominic Mayers (talk) 00:17, 29 August 2018 (UTC)

"All swans are white" can be proven false and is, hence, a falsifiable statement,

This statement below the picture is directly in contradiction with the definition. Popper insisted very much that falsifiable does not mean that it can be proven false. See the second note after the first sentence. Dominic Mayers (talk) 22:17, 28 August 2018 (UTC)

Here is the second note after the first sentence in the article.

"We must distinguish two meanings of the expressions falsifiable and falsifiability:
"1) Falsifiable as a logical-technical term, in the sense of the demarcation criterion of falsifiability. This purely logical concept — falsifiable in principle, one might say — rests on a logical relation between the theory in question and the class of basic statements (or the potential falsifiers described by them).
"2) Falsifiable in the sense that the theory in question can definitively or conclusively or demonstrably be falsified ("demonstrably falsifiable").

"I have always stressed that even a theory which is obviously falsifiable in the first sense is never falsifiable in this second sense. (For this reason I have used the expression falsifiable as a rule only in the first, technical sense. In the second sense, I have as a rule spoken not of falsifiability but rather of falsification and of its problems)"

--Dominic Mayers (talk) 08:45, 29 August 2018 (UTC)

If you are saying the illustration should be deleted because it's misleading, unclear, counterproductive, and confusing, I strongly agree. I think the most powerful miscommunication part of that is the image itself. An actual black swan is not needed, only a realistic imagined possibility of a (hypothetical) black swan is needed. Or in Popper's words; "a purely logical affair."

From the black swan's vague, unclear caption: ""All swans are white" can be proven false and is, hence, a falsifiable statement," —Corrected: "All swans are white" can logically (or realistically hypothetically) be proven false and is, hence, a falsifiable statement." —However, as you point out, that's in contradiction with the rest of the caption. —Corrected: since possible evidence of black swans is reasonably possible, proves it to be falsifiable and such evidence can be provided....

I like this definition: https://www.collinsdictionary.com/dictionary/english/falsifiable

Dominic Mayers, above, quotes:

"But when is a statement falsifiable? It is of great importance to current discussion to notice that falsifiability in the sense of my demarcation criterion is a purely logical affair. It has to do only with the logical structure of statements and of classes of statements. And it has nothing to do with the question whether or not certain possible experimental results would be accepted as falsifications.  — Popper 1983 p. XX"

However, the image itself is deceptive since it implies that real black swans are a part of falsifiability. They are not. The real black swan confuses logically falsifiable with falsified. That image is counterproductive.

Example; a lay valid argument: "Unlike Creationism, which cannot be falsified, evolution theory is scientific because it can be falsified a zillion ways, for example; a modern screwdriver, dog, or flowering plants found in the belly of a T Rex dinosaur found in undisturbed rock would falsify the current theory of evolution." —No real swan or dog needed. The illustration, even without the caption implies the opposite. I strongly suggest deleting the confusing image. A better illustration might even be a cartoon of a purely hypothetical falsification. Cheers!
--2602:306:CFCE:1EE0:C5FF:F292:7567:1FB5 (talk) 17:33, 28 October 2018 (UTC)Doug Bashford

Just to add that, if we do not take "if" to mean "if and only if" and if we accept to be informal, it is correct to say if we can provide an actual observation that contradicts the theory then the theory is falsifiable. It does informally imply falsifiability, as much as something as informal as "actual observation" can imply anything, but it's certainly not the definition, because the definition does not deal with what is actually possible in real life, whatever that means. It only deals with statements, which are the only things that can be dealt rigorously. The fact is that all reasonable books that I know about falsifiability give the definition in terms of statements. Here is a case that I find interesting. Chalmers in the 1982 edition of his book "What is this thing called Science", did not make a clear distinction between facts as actual observations and facts as basic statements, but the latter was assumed. In the 1999 edition, he wrote two pages and a half to insist on the distinction and to say that in science, we write theories and the facts (corroborating or falsifying it) in terms of statements. In a way, I feel that we are being picky here, because anyone with basic common sense should think that there is no other way that we can proceed in science. This being said, I have no opinion about the picture. I was talking about the text below it. --Dominic Mayers (talk) 18:16, 28 October 2018 (UTC)

Also, we should not confuse "to exist in real life" and "to be alive". There is a formulation of evolution theory that is falsifiable, but we do not need that a modern screwdriver in the belly of a T Rex fossile is in principle possible in the real life of a paleontologist, whatever that means. It is sufficient that this observation, irrespective of the complexity of real life issues, can be consigned as a basic statement. Of course, the issue of rigor as simply been moved to the definition of the set of basic statements. Sure, but that is the whole point: we want to separate what can be stated rigorously from what depend on conventions. --Dominic Mayers (talk) 18:39, 28 October 2018 (UTC)

Wow! I wouldn't disagree but we certainly don't want that level of formality in the lede section! What bugs me in the Lede is this; the second sentence:

"For example, the claim "all swans are white" is falsifiable since it is contradicted by this basic statement: "In 1697, during the Dutch explorer Willem de Vlamingh expedition, there were black swans on the shore of the Swan River in Australia", which in this case is a true observation."     I don't think so.

Implied in statement; (Reworded): For example, the claim "all swans are white" is falsifiable since it is contradicted by this basic statement: it is false. Obviously anything false or falsified is falsifiable.

Or (reworded): For example, the claim "all swans are white" is falsifiable since it is contradicted by this basic true observation/fact: "Not all swans are white". Again obviously anything false or falsified is falsifiable, but again, that's not why it's falsifiable. That would imply that before the black swans were found, "all swans are white" was not falsifiable. But that's untrue, the statement was falsifiable independent of (our knowledge of) darker swans. It seems we are confusing falsifiable with falsified. The same argument applies to the illustration/caption.

Here's an analogy: Something bent is obviously bendable, but being bent is not why it's bendable as the article implies. The nail was bendable before it was bent. The article confuses bendable with bent. The claim "all swans are white" is falsifiable regardless of the existence of black swans and regardless of our knowledge of any black swans. I believe it is now, and was long ago falsifiable —because the possible discovery of colored swans (falsification) is/was reasonable. Likewise, there is no conceivable way to falsify the claim: "Ghosts exist." Therefore the claim is unscientific. Cheers!
--2602:306:CFCE:1EE0:C5FF:F292:7567:1FB5 (talk) 04:48, 29 October 2018 (UTC)Doug Bashford

Academic Paralysis here, & Communication

Academic Paralysis is when academics, perhaps used to peer-reviewed journals, are more concerned with not being wrong than they are with good writing —and most importantly; with the effective Communication of ideas. The result is muddled, over-lawyerly speech, typically with too many clauses and sub-clauses etc, and often; with inappropriate jargon or stilted language. There are other style flaws, such as the seeming aversion to examples even when effective Communication is begging for some. Everybody on this page including Popper himself seem to be victim of this. For example, all the attempts to cleanly define "falsifiable." But only Popper has an excuse for this, since he was not writing for Wikipedia. Wikipedia stresses that it does NOT NOT NOT want to emulate a peer reviewed journals! Instead it values the effective Communication of ideas to average non-specialists. Not customizing one's writing to the targeted audience is ALWAYS crappy writing.

For example, compare this clean definition: —falsifiable, adjective, designating or of a statement, theory, etc. that is so formulated as to permit empirical testing and, therefore, can be shown to be false. Webster’s New World College Dictionary, 4th Edition. Copyright © 2010 https://www.collinsdictionary.com/dictionary/english/falsifiable

...a good place to start. In our context we might replace "formulated" with "structured," and "empirical," with "logical." Whatever. Add a few simple sentences to clarify; done. Or: adjective: capable of being tested (falsified) by experiment or observation.

But for added complexity other key words have multiple definitions, I choose def3: https://www.merriam-webster.com/dictionary/empirical 3: capable of being verified or disproved by observation or experiment —empirical laws—     That's nothing compared to "love." Cheers!
--2602:306:CFCE:1EE0:C5FF:F292:7567:1FB5 (talk) 01:39, 29 October 2018 (UTC)Doug Bashford

There is no paralysis here. One or even two definitions in dictionaries should have little weight in comparison to many articles on falsifiability and many books on Popper epistemology, which simply give the same definition as Popper. The subject is falsifiability, which was defined by Popper. He is the primary source. We must present it, not something else, in the light of secondary sources. If another notable philosopher had defined falsifiability in a different way, we could raise the question how much weight we must give to it, but only Popper has defined falsifiability. So, the question is not even raised.

BTW, the "definition" in Collins has simply confused a statement that Popper wrote to motivate the definition with the definition itself. Yes, it's true that falsifiability of a theory was defined by Popper in such a way that the theory can be empirically tested and, therefore, can be shown false. Yes, the definition implies this property, but this is not the definition. As far as the Merriam definition is concerned, it's about the adjective empirical, which is a general concept that has been defined in different ways by different philosophers. We should not confuse it with the technical term "falsifiability" introduced by Popper. --Dominic Mayers (talk) 02:59, 29 October 2018 (UTC)

However, I do sympathize with your concern. It's difficult to define falsifiability in one sentence, even one paragraph. The important philosophical issue of the empirical basis is raised by the definition. This issue is implicit in the concept of basic statement, which is hard to define but fundamental in the definition. If we define falsifiability in a way that avoid this issue, then we have defined something else. --Dominic Mayers (talk) 03:10, 29 October 2018 (UTC)

Difficult? Yes, for me nothing is more difficult than attempting to communicate more than small-talk, which is typically little more than expressive grunting. I see gibberish in the lede section, I've explained why. If the technical jargon contradicts plain English, (sounds-alike jargon, SPIT!) then perhaps the jargon itself needs to be defined before using it? Personally, for me nothing is more challenging than attempting effective communication. Do you know as much about that topic, those skills, as you do about Popper? I ask because very little of what you write is getting thru to me. Since I suspect you know about Popper, then the problem must be communication. The problem might be on my end. But I have seen you make very little effort to that end; all I see are jargon-laden appeals to authority and dogma, not plain English attempts to explain or teach. If one thinks effective communication requires less than one's full effort and much time, one is destructively ignorant of the topic. I've tried to reword my arguments several ways to try and communicate with you, and you? Respectfully; it seems like you don't even understand my questions/challenges, you brush them aside, so one must wonder what you do understand.

"....should have little weight in comparison to many articles on falsifiability and many books on Popper epistemology..." That aint worth shit here. All that matters here is what the reader gathers from the article. If the reader doesn't get it, or worse; gets it wrong, the article and the writers fail. Encyclopedias by definition condense info which means almost by definition the writer will be conveying a partial truth or distortion. (We have no godlike writers.) Therefore the writer's task is to decide which "untruth" to tell. I'm pretty sure we don't want a portrayal that seems false on it's face, seems self-contradictory or illogical. If the writer holds the many books on Popper etc as holy, as not subject to that "partial truth or distortion," perhaps he is paralyzed. (While I hold Popper and Kuhn's genus along side Eisenstein's, not so Popper's writing communication skills.)

For me Popper's and Kuhn's worldviews have been highly useful when truth seeking. If we can pass that on to others I will be content. I want something rugged and useful. Tools. The poli-econ motivated anti-science, anti-truth, anti-intellectualism movements are growing exponentially.

Inappropriate jargon has long been a part of my job and is a pet peeve. Over the years it has been my observation that the worst articles are often technical articles because respected experts tend to falsely assume 1)writing/explaining/teaching requires little effort or 2)of course they own the writing skills, time, and talents, —or because they no longer have the ability (or desire) to communicate complex ideas with Joe Sixpack on Joe's terms. Laugh! but sometimes I also see what seems like precocious 13-year-olds attempting to impress self, peers, or others. Laugh!!, even: cram for a final; write a Wikipedia article!

I think the Lede may be a bit out of specs, you may want to review this: MOS:LEAD Wikipedia:Manual of Style/Lead section. Cheers!
--2602:306:CFCE:1EE0:3044:A2C3:2683:987B (talk) 14:59, 2 November 2018 (UTC)Doug Bashford

I agree that the lead section needs improvement. My mistake and perhaps also the mistake of those who wish a simpler version, I feel, is to think that we must "fully" define falsifiability in the lead. Let me explain what I mean by "fully" using some examples. The statement "We say that a theory is falsifiable if it can be proven wrong in an experiment" is a complete definition. It is a complete definition, because as soon as we know what is meant by "proven wrong in an experiment", and usually we have a good idea of what it means, the notion of falsifiability is fully determined. It is a complete definition, but it is wrong. When you think about it, it makes no sense, because if it can be proven wrong, then it has to be wrong. Because of that, some people will add "in principle", but it does not help much, because "in principle" or "possibly" is unclear, not defined. I had no idea how to turn "in principle" into a rigorous concept. I had no idea what this supposedly easy to understand definition meant. In any case, it's not the definition. It simply is not. On the other hand, the following statement

Falsifiability is a property, a sort of potentiality used to characterize any theory that possibly may clash with a particular state of affairs. According to its more simple formulation, it tells us that, when such a clash takes place, the theory in question becomes falsified.

— Carlos E. Garcia, Popper's Theory of Science. An apologia.

is not a full definition. It is the way used by the author to gently introduce the full definition, which he says, will come later. Most notable authors on the subject use this kind of gentle approach, even Popper himself does so. Here is the first statement used by Popper to "define" falsifiability in Logic of Scientific Discovery:

... not the verifiability but the falsifiability of a system is to be taken as a criterion of demarcation. ... In other words: ... I shall require that its logical form shall be such that it can be singled out, by means of empirical tests, in a negative sense: it must be possible for an empirical scientific system to be refuted by experience.”

— Karl Popper, The Logic of Scientific Discovery.

Garcia's statement and Popper's statement are not full definitions. In Garcia's statement, we don't know what is the mentioned property. Even if we know what is meant by "a property", we still don't know what is the property in the definition. The actual definition depends on our choice for this property. In Popper's statement, we don't know what is the required logical form. The actual definition depends on the required logical form. The actual full definitions that are given later by Garcia and Popper in their respective book are identical and are both given in terms of basic statements. Note that despite the "possible" and "possibly" used in these statements, we have that, if the theory is possibly contradicted by an experiment, it must be incorrect. So, the same problem is there - these statements are unclear, but here, at the least, there is no claim that a full definition is given. We understand that it will become clear when we will have the full definition and, indeed, the correct full definition makes it clear and makes us realize that it is a deep concept.

My mistake was to feel that, in a lead, we must give the full definition because, as pointed out in MOS:LEAD : The lead should stand on its own as a concise overview of the article's topic. It should identify the topic, establish context, explain why the topic is notable, and summarize the most important points, including any prominent controversies. But, given your comment, I realize that a full definition might not be a good idea.

However, what was totally unacceptable and worst than the current version, was to provide an incorrect full definition in the lead. Why do you think I started to edit that article? It was because the definition made no sense to me. It was perhaps considered simple and natural by some people, but if you looked at it carefully, you could see the contradictions. In that sense, I feel that what I wrote was a necessary improvement. I agree that providing a gentle, incomplete, but correct definition would even be better. --Dominic Mayers (talk) 16:56, 2 November 2018 (UTC)

In fact, I am looking again at MOS:LEAD and it is clear that the previous lead before my edits did not respect at all these guidelines. It was only an incorrect supposedly natural definition together with one or two statements saying it demarcated scientific theories. It did not at all identify the topic, establish context, explain why the topic is notable, and summarize the most important points, including any prominent controversies.. I admit that the current version is not much better, but at the least it does not give a definition that is non sense. --Dominic Mayers (talk) 19:12, 2 November 2018 (UTC)

Again you frustrate my attempts at communication by brushing aside all my attempts, every single paragraph with no comment and restarting your little-changed, unaffected (by me) monologues, MONOlogues, refusing a dialog. First, I agree we need a complete definition in the lede, but what we don't need are all the lawyerly "subclauses" (crap). Typically a definition is given in first few lines or the first paragraph if possible. To "fully" define falsifiability, we DO NOT attempt Popper's lousy, inappropriate writing style, (or worse; attempt to paraphrase a quot,) we attempt to cleanly explain the concept, a rather simple, like-duh one. The concept is in the public domain, he is unneeded. Second you are using foggy, vague, confusing nearly meaningless language. Is it possible you are using terms-of-art or jargon or are aping previously defined Popper-speak without recognizing it? In any case, those words are crap, too vague, unusable, I have no idea what the Hell you are talking about. IOW, stop repeating yourself (others?) and start doing some actual explaining. You might even consider talking to me about what I've written...you may or may not agree, in full or partially I have no fucking idea. And why the hell are you posting incomplete partial (garbage) popper quotes at me? I have no desire to hear your self-musings.

Crap example:

The statement "We say that a theory is falsifiable if it can be proven wrong in an experiment" is a complete definition. Whether it is the correct definition is irrelevant here. The point is that as soon as we know what is meant by "proven wrong in an experiment", and usually we have a good idea of what it means, the notion of falsifiability is fully determined.

That is so sloppy, how dare you call that anything close to a definition. Sloppy thinking, vague sloppy words...sounds more like a teenager thinking aloud. Here's the biggest fix: change "if it can be proven wrong" to "if it could be proven wrong." That changes the physical into the logical, or feasible, as Popper intended. You keep making that error over and over, as I've attempted to explain again and again. To not a fuckin word from you.

Other problems with quotes is "empirical," which as I noted to your silence, has several definitions (as in vague crap). Since you refuse to actually communicate, I'll not put more effort into repeating myself, I guess I'm getting smarter.

So, 1)are you or are you not claiming "all swans are white" was not falsifiable before black swans were discovered? 2)Do you think you have answered that question, if so, where? 3)Why am I talking into a well?

"Why do you think I started to edit that article?" I am not referring to what was written before I got here since I have no knowledge of it. Cheers!
--2602:306:CFCE:1EE0:3044:A2C3:2683:987B (talk) 23:23, 2 November 2018 (UTC)Doug Bashford

You wrote First, I agree we need a complete definition in the lede, but I was expressing that the exact opposite would be better. So, I don't think you communicate very well. --Dominic Mayers (talk) 23:42, 2 November 2018 (UTC)

And to answer your question, the empirical status of a theory, in accordance with the popperian criterion, is never affected by the outcome of an experiment. So, if "All swans are white" is falsifiable, it is falsifiable before and after any experiment. BTW, it is falsifiable, because the ultimate background theory, the logic, allows basic statements such as "Today, this swan on this river is black", which contradicts the theory. The logic background theory is there before we can even write the theory "All swans are white". --Dominic Mayers (talk) 00:20, 3 November 2018 (UTC)

Yup. 1)So what is this confusing, vague if not misleading sentence doing in the Lede paragraph?

"For example, the claim "all swans are white" is falsifiable since it is contradicted by this basic statement: "In 1697, during the Dutch explorer Willem de Vlamingh expedition, there were black swans on the shore of the Swan River in Australia", which in this case is a true observation."

"since" means because. Only about 443 people have tried to point this recurring error out to you.

Corrected: For example, the claim "all swans are white" is falsifiable since real colored swans are a reasonable possibility.

2)What is this pretentious, confusing lawyered-up verbiage doing in Wikipedia as the lede sentence?

"A statement, hypothesis, or theory has falsifiability (or is falsifiable) if it is contradicted by a basic statement, which, in an eventual successful or failed falsification, must respectively correspond to a true or hypothetical observation.[1][2]..."

Why not clean and simple paragraph, like this?

Falsifiability or refutability of a statement, hypothesis, or theory is the inherent possibility that it can be proven false. A statement is called falsifiable if it is possible to conceive of an observation or an argument which negates the statement in question. In this sense, falsify is synonymous with nullify, meaning to invalidate or "show to be false".

Or something like this:

A statement, hypothesis, or theory has falsifiability or refutability if there is the possibility of showing it to be false. It is falsifiable if it is possible to conceive an empirical observation or a logical argument which could refute it.

It's really a very simple concept. No confusing grandiloquence or logorrhea (shitty writing) needed!

As I recall Popper didn't include "logical argument" etc, but it was added later to meet the needs of astronomy & astrophysics, nonNewtonian etc where thought is often outside the realm of empirical observation. The topic is falsification, not Popperism. CHEERS!
--2602:306:CFCE:1EE0:3044:A2C3:2683:987B (talk) 21:38, 3 November 2018 (UTC)Doug Bashford

Your simple notion of falsifiability is not verifiable in secondary sources such as Chalmers, Boyer and Garcia to mention only a few. The concept of falsifiability is not the simple idea that the theory can be possibly false or proven false. It's not that. It has nothing to do with what could possibly happen in some future. It has only to do with its relationship with the observations that are possible in principle (that is, if we ignore the theory). In a way, if we insist to give a criteria in terms of hypothetical observations, it has more to do with the hypothetical observations that were considered possible in the past, that is, before the theory. Popper wrote something that is enlightening on this respect: "Not for nothing do we call the laws of nature ‘laws’: the more they prohibit the more they say." Here, we see the idea that the value of a theory is that it clashes with observations that would otherwise be possible. Such a theory could be totally impossible to prove false and it would still be falsifiable. --Dominic Mayers (talk) 22:51, 3 November 2018 (UTC)

You claim without support: "The concept of falsifiability is not the simple idea that the theory can be possibly false or proven false. It's not that." Bullshit, that's the basic idea, particularly from science's (as opposed to philosophy's) POV, —if you think it needs further tweaking and feathering out, the lede section is not the place to attempt that. In this context, convention says philosophy takes the far, far back seat to the working tools of science.

Dude, do you have any idea how bad your communication skills are? I hate to attempt mindreading, but it looks like you think communication is all about the transmittor —you. Have you ever tried to parse your own words?...like your above paragraph? For example, 3/4 of it, —after the word "future,"— it's all logical puff; agreement, unsupported opinion, and non sequitur. Bloviation. But improving. Bashford's First Rule of Writing: Nobody cares about your words as much as you do. (Mom's only faking it.) It's like you are so excited with your ideas, with yourself, you just can't be bothered with what your fingers are doing, with what those words could mean to somebody else, with actually communicating.

What's all the jumping around for anyway? We are largely in agreement. My examples didn't mention the future. By the way, they are not "my" examples, they were long in use, largely unmolested before you started muddling around here last April, in fact one of them still shows up in the Bing search cache, nice, smooth, and comprehensible. What makes you the expert in writing Wiki Lead sections and effective communication? So yer saying "Trust me, while I can't even speak plain English, I'm not crazy, everybody else was! This is MY article now, MINE MINE MINE!!!" lol.

I guess you missed it the first time: Academic Paralysis is when academics and wannabees are more concerned with not being wrong than they are with good writing —and most importantly; with the effective Communication of ideas. The result is muddled, over-lawyerly speech, typically with too many clauses and sub-clauses etc, and often; with inappropriate jargon or stilted language. Some people are so self-absorbed they try that in the Lede. Cheesh. Cheers!
--2602:306:CFCE:1EE0:3044:A2C3:2683:987B (talk) 04:06, 4 November 2018 (UTC)Doug Bashford

You are attacking me personally and about the text you don't say much that is useful to me. Anyway, I am patiently responding to whatever can be usefully addressed. You wrote Bullshit, that's the basic idea, particularly from science's (as opposed to philosophy's) POV. If there is another POV, please provide the primary sources that are the prominent supporters of that POV and then the secondary sources. You wrote We are largely in agreement. My examples didn't mention the future. I used the concept of future vs past to help convey the difference between your definition and the epistemological definition. It's not the standard way. Ignore it, if it does not help you. Let me try again with an example. Before Galileo, people assumed that objects fall faster if they are heavier. In fact, it was believed that the speed was proportional to the weight. So, an hypothetical observation was that an object of 100 kilo would reach the ground 100 time faster that an object of 1 kilo. This hypothetical observation has nothing to do with what can actually be observed. Galileo expressed a law that contradicted this hypothetical observation. It was useful because it prohibited some observations, even though these observations have zero chance to occur. This is why Popper says that falsifiability is a purely logical affair and has nothing to do with what can be observed. Now, how do we capture this notion? Popper and all the secondary sources after him used the notion of basic statements. Now, you might not like it and I might not like it either, but this is what we have in secondary sources. I already agreed that the lead can be improved. Perhaps, we should avoid using the expression "basic statement" in the lead, but this does not mean that we should give an incorrect, naive and confusing definition in the lead. --Dominic Mayers (talk) 15:08, 4 November 2018 (UTC)

The distinction between the two meanings of falsifiability is NOT trivial.

It is a source of confusion to think that the distinction between the two meanings of falsifiability that Popper made is similar to the trivial distinction between provable and proof, the first being the capacity to be the object of the second. Do you think that Popper would have insisted so much that we understand such a trivial distinction? Of course not. So the actual distinction is not trivial at all. I would agree that it was a bad choice of terminology. Why Popper used a term that has a common meaning and then insisted so much that it has a different technical meaning? Perhaps, because he felt that it conveys very well the purpose of the definition. Indeed, the purpose is clearly that a falsifiable theory can be falsified by an experience. This purpose is not the definition, because, as Popper explains, it can hardly be made rigorous. The separation between the technical definition and its purpose within the methodology is very useful. It allows a more precise discussion. --Dominic Mayers (talk) 03:53, 9 December 2018 (UTC)

Before you edit the lead or any other part of the article, read this correctly

"We must distinguish two meanings of the expressions falsifiable and falsifiability:

"1) Falsifiable as a logical-technical term, in the sense of the demarcation criterion of falsifiability. This purely logical concept — falsifiable in principle, one might say — rests on a logical relation between the theory in question and the class of basic statements (or the potential falsifiers described by them).

"2) Falsifiable in the sense that the theory in question can definitively or conclusively or demonstrably be falsified ("demonstrably falsifiable").

"I have always stressed that even a theory which is obviously falsifiable in the first sense is never falsifiable in this second sense. (For this reason I have used the expression falsifiable as a rule only in the first, technical sense. In the second sense, I have as a rule spoken not of falsifiability but rather of falsification and of its  problems)"

--- Karl Popper, The logic of Scientific Discovery.

Popper is not talking about the distinction between falsifiability and falsification. He is talking about a distinction between two meanings of the term "falsififiability" (and the same for the term "falsifiable"). He is very clear that the other meaning (which is that the theory can be the object of a falsification) is not falsifiability. He is very clear that the definition of falsifiability must be given in terms of basic statements and other statements, only relations between statements. This point is verifiable in many secondary sources that are highly reliable. Dominic Mayers (talk) 04:34, 9 December 2018 (UTC)

For example, the statement

To be falsifiable a theory must make a testable prediction.

which is inspired by this web page, might seem a good alternative to the current lead sentence. Unfortunately, it says almost nothing. It just move the question to what is a testable prediction and, for Popper, testable and falsifiable are synonymous. So, we could have written To be falsifiable a theory must make a falsifiable prediction... Oh well... Dominic Mayers (talk) 03:01, 15 December 2018 (UTC)

Modifying the caption for the image

I propose the following text.

This picture corroborates the basic statement "On this day, there were black swans on this river", which contradicts the law "All swans are white". This contradicting basic statement alone makes the law falsifiable. It  would still be falsifiable, even if there were only white swans.

This might seem an intricate sentence that could be simplified by removing the reference to the basic statement. However, this is exactly the challenge that we must face to explain falsifiability. A reference to basic statements is fundamentally necessary to explain in the most simple way possible what is falsifiability. It is necessary to create the fundamental separation between the logical aspect and the methodological aspect, which separation is at the heart of the concept of falsifiability. Popper insisted so much on this. So, the sentence is not too intricate. The reference to the basic statement is not superfluous. It removes any possible confusion and makes it unnecessary to use unclear expressions such as "in principle". It makes clear why there is no need to even be remotely able to show the existence of black swans: it is sufficient that the observation statement exists and that it is accepted as valid by a simple convention among scientists.

It is not what we call a fine point. It is a fundamental point that deserves to be emphasized and the caption is a good place to do that, because the picture illustrates very well the phase were we corroborate the basic statement, which contradicts the law. It is the perfect place to mention this.

--Dominic Mayers (talk) 17:59, 20 December 2018 (UTC)

Removing the {{cn}} tag in the caption

I've removed your {{cn}} tag, and the lengthy rationale, from the picture in the article. In the context of the caption black swans patently do exist, as there is a picture of two of them right there. If you have issue with the definition of the term "falsifiable statement" (which seems to be the case, rather than the existence of black swans) then you need to reposition the {{cn}} tag - however it seems that the Overview section covers this definition. Before you consider adding the tag again, can you clarify why it needs adding here? Your post above doesn't actually discuss what you think is wrong with the statement ""All swans are white" can be proven false and is, hence, a falsifiable statement, since evidence of black swans proves it to be false and such evidence can be provided" Chaheel Riens (talk) 12:56, 19 December 2018 (UTC)

I am glad to discuss the issue in the talk page. I value your effort to improve this article and I will not ignore your argument. Yes, there are two black swans in the picture. However, I could also show you pictures with two black unicorns. They will be fake pictures. This remark might seem to have no practical value, because obviously, one would say, the black swans really exist and we could even travel and see them for real, etc. Yes, but even then, Popper and most philosophers of science, will explain that we cannot really prove that black swans exist. This is not an irrelevant and fanatical issue, but is on the contrary at the heart of important discussions in the philosophy of science. This is the kind of issues that underlie Popper's discussion with the Vienna circle and have motivated his precise definition of falsifiability. This article is not about the common meaning of falsifiability, but about the epistemological meaning of falsifiability, where these issues are important. Now, in this perspective, read again the quote from Popper that is given above, especially the sentence  

"I have always stressed that even a theory which is obviously falsifiable in the first sense is never falsifiable in this second sense [that it can be falsified]."

— Karl Popper

Here Popper explains in general what I have pointed out in the specific case of the black swans. So, Popper explains that it is not even true that "can be falsified" is a particular case of falsifiable (in the epistemological sense). On the contrary, Popper says that, even when it obviously falsifiable in the epistemological sense, it is never falsifiable in the sense "can be falsified". In other words, rigorously speaking, even if "All swans are white" is obviously falsifiable, what Popper says implies that we cannot prove that there are black swans. Therefore, it cannot be the reason why it is falsifiable. Something that cannot be proven rigorously cannot be a criterion for the rigorous concept of falsifiability. --Dominic Mayers (talk) 15:34, 19 December 2018 (UTC)

The existence of Black swans is supported by multiple reliable sources, whereas unicorns - black or otherwise - are not. "Popper says that we cannot prove that there are black swans". That's not what Popper says. What he says is that we cannot prove that there are no black swans - based on the observation or lack of. There's a subtle but important difference there. Can you provide sources that show that black swans don't exist?

Even the most ardent philosopher and scientist would struggle to remain credible by taking a serious stance on denying the existence of black swans. At some point it has to be accepted that they exist, as the evidence for outweighs the evidence against. Chaheel Riens (talk) 18:32, 19 December 2018 (UTC)

I have to repeat Popper's sentence:

"I have always stressed that even a theory which is obviously falsifiable in the first sense is never falsifiable in this second sense [that it can be falsified]."

— Karl Popper

This sentence is very general. It applies to all theories or statements and thus it applies to the statement "All swans are white." When we apply it to "All swans are white", it says (I mean it implies) that we cannot definitively or conclusively or demonstrably falsify that "All swans are white". This means that we cannot prove that "There are black swans", because if we can prove it, then we can definitively or conclusively or demonstrably falsify the statement "All swans are white".

So, please read carefully Popper's quote, not only the last sentence, but the entire quote where he gives the two meanings of falsifiability. I know that it might seem weird from a common sense perspective to say that we cannot demonstrably falsify "All swans are white", but Popper has written a very clear general point and obviously it applies to the statement "All swans are white".

You wrote What he says is that we cannot prove that there are no black swans - based on the observation or lack of. Yes, Popper certainly said that elsewhere, but not in the above quote. In the above quote he said "even a theory which is obviously falsifiable in the first sense [his technical sense] is never falsifiable in this second sense [in the sense demonstrably falsifiable]" Read the entire quote again. Ask yourself what this means. What does Popper mean by "a theory is never falsifiable" where "falsifiable" is taken in its usual sense of "demonstrably falsifiable"? How does it apply to the specific statement "All swans are white"?

You wrote Even the most ardent philosopher and scientist would struggle to remain credible by taking a serious stance on denying the existence of black swans. We understand that, but yet there can be weird scientists that claim to be serious and yet will deny that black swans exist. Sure, the true scientists can ignore them, but the point is made that it must be a convention among the "true" scientists. Popper insisted to separate what depends on convention in the methodology from what is purely logical, i.e., depend only on the relationship between statements. In fact, he insisted that the convention is not whether a statement such as "there are blacks swans now on this river" is true or not, but only whether it is a valid observation statement, which he calls a basic statement. Note that whether or not the basic statement (which contradicts the theory) is empirically true is not important. There is no need to achieve any agreement on this. We only need to agree that it is a valid observation statement. Popper discusses in details that even this obvious fact must be a convention. He argues that it is hardly an issue to reach an agreement on such a convention, but it is nevertheless a convention. He says that once we have fixed by convention what are the basic statements, then what is falsifiable can be determined rigorously. He insisted very much that we separate the logical aspects from the methodological aspects. He explained, as he does indirectly in the above quote, that the methodological aspects can hardly be made rigorous. This is what he implies when he says that "demonstrably falsifiable" is never possible. --Dominic Mayers (talk) 20:25, 19 December 2018 (UTC)

I think we're approaching this from two slightly different angles. You're very into the technicalities and finer points of Poppers theorem, whereas I'm taking issue on a much simpler scale with a small part of the topic - to whit, the claim that black swans cannot be proven to exist. I suggest that another principle is applied - Occam's razor - and we consider which is the more likely scenario:

• There is a global conspiracy created with the sole purpose of falsifying evidence surrounding the existence of black swans
• Black swans exist

It could also be argued that any scientist who claims that black swans don't exist is not really by definition a serious scientist. You yourself use the description of "weird". I'm all for opposing viewpoints, but the black swan analogy is not a wise choice.

To summarise - Your issue seems to be with interpretation of the theorem, whereas mine is much simpler, and with the placement of a {{CN}} flag in a Wikipedia article. Your interpretation may be correct in strict definition of the theorem, however from a Wikipedian point of view the {{cn}} tag was improperly placed as there is no citation required to show that Black swans exist. In fact, we have an entire article dedicated to this very topic - WP:BLUE. Chaheel Riens (talk) 03:22, 20 December 2018 (UTC)

OK, you reassure me a bit. I thought you did not understand Popper and all the great modern philosophers that explained his falsifiability and wanted to modify the article in view of this incorrect understanding. So, I wanted to help you to better understand. Now, my understanding is that your concern is only that a {{cn}} tag in a caption seems weird and misplaced. The problem is that the text in the caption does a lot more than only describing the picture. It is the same kind of significant content that could appear in the body of the article and therefore, if it provides some significant content, it has to be managed as such. For example, the first phrase in the caption is All swans are white" can be proven false and is, hence, a falsifiable statement,... This is a very significant phrase and it is directly in opposition with Popper's definition. What follows is not better: ... since evidence of black swans proves it to be false .... This is exactly the opposite of what Popper explains in the above quote about the two meanings of falsifiability. I recall that it says that a falsifiable statement is never falsifiable in the sense of demonstrably falsifiable. In a different context, say within an article about swans, a caption that would state that we have a proof that black swans exist would not be problematic. However, it is problematic here because Popper insists a lot that from his technical perspective this kind of statements are hardly rigorous and therefore in no way constitute a criterion for his technical falsifiability. --Dominic Mayers (talk) 04:18, 20 December 2018 (UTC)

After a second lecture of your last comment, I see that your concern is not only a misplaced {{cn}} tag. You clearly also express a concern about Popper's way to motivate his technical logical criterion. You argue that the statement "black swans exist" is more reasonable than a global conspiracy. This is not a concern about the location of the {{cn}} tag. It expresses a concern about Popper's way to explain why his criterion is purely logical. Indeed, he uses a purely logical criterion, because technically speaking anything else is hardly rigorous. Nevertheless. I can reassure you that, of course, Popper also accept that the statement "black swans exist" is way more reasonable than a global conspiracy. However, this important way that you used to accept some statement is part of the method and has not much to do with his perfectly rigorous falsifiability criterion. His falsifiability criterion is NOT the method. It's only a logical criterion used to demarcate scientific statements from other statements, given a convention on what are the basic statements. This convention is part of the method. The next step, which is a demarcation between true and false statements is also part of the method. So, it is a purely logical criterion used within the method. It has no meaning outside the method. Trying to make sense of it as a stand alone criterion that includes the method when it is in fact only a technical logical criterion within the scientific method can only bring confusion. --Dominic Mayers (talk) 05:11, 20 December 2018 (UTC)

Yes... But once again it comes down to how the editor chooses to interpret the article. It's been many, many years since I did philosophy at A-level, and these days I tend to take things more in line with Occam (as I mentioned above) which makes things a lot simpler in real life. As far as Wikipedia is concerned there is no {{cn}} required for the statement that Black swans exist - ergo it was removed. If the statement is that confusing then perhaps it should be replaced with something more abstract, rather than something that - as far as Wikipedia is concerned - can be shown to be false. However this would be tricky as the article mentions the Black Swan fallacy in the lede and several times throughout the text, making it an intrinsic part of the article.

Either that, or at perhaps change the text from an image caption to a section within the article itself. The image caption is already at about the limit, and if it requires clarification or expansion it will be too big. Chaheel Riens (talk) 08:51, 20 December 2018 (UTC)

It seems that you missed this phrase in the banner ... without removing the technical details. The idea is that making a text simpler should not mean that it becomes incorrect. I argued that the text is incorrect, wrong from a Wikipedia perspective, because it contradicts Popper and secondary sources. It breaks the verifiability requirement. Your argument ignores this, because you say that it is only a text about the existence of black swans and there is no need to verify that. However, the text is NOT only about the existence of black swans. This argument that you repeat many times relies on a false assumption: the text is NOT about the existence of black swans only. It is about falsifiability, because it mentions "falsifiable" and makes assertions about it. Moreover, if it was as you suggest only the statement that black swans exist, it would break another wikipedia rule, which is that it is irrelevant. The common understanding that black swans exist is not important in the subject of the article. This last point is very simple. You should like it because of its simplicity. Whether black swans exist or not is not related to the article. Let me emphasize this simple point. There would be no black swans, only white swans, and "All swans are white" would still be falsifiable. This is one of the most fundamental, basic and simple concept that one must understand before considering editing this article. Therefore, to conclude, if as you say, the text only says that black swans exist, such a text might indeed need no source, but it would have no place in the article. Either way you decide to take it, as a text about falsifiability or only a text about the existence of black swans, the occam logic does not work here and the text breaks wikipedia rules. --Dominic Mayers (talk) 14:24, 20 December 2018 (UTC)

No. Your above statement shows that while you have a good grasp of Poppers theorem, you don't understand what a {{cn}} tag is used for. You cannot use it to claim that the phrase "black swans exist" needs to be cited or is false. This is Wikipedia, not some philosophy discussion in a Hipster coffee shop. I should have realised that when you first responded with the claim that their apparent existence could be faked. That is clearly not the rational response one would expect, nor is it likely that reasonable discourse would follow.

I'm not even sure why I'm bothering to respond to this. Do what you will with the article, but don't put back the {{cn}} tag. If you don't understand why you shouldn't put it back, then stop editing Wikipedia until you do. Chaheel Riens (talk) 16:35, 20 December 2018 (UTC)

No. I never claimed that "black swans exist" needs to be cited or is false. I did not claim that it needs to be cited, because it is not the phrase that I consider. I consider the overall statement about falsifiability in the caption. I said nothing and have nothing to say about the sentence "black swans exist" except that it is irrelevant and not the sentence that I am concerned about. I said that the overall text in the caption is incorrect, not false, but incorrect in the following sense that it breaks wikipedia rules. Whether it is false or true is not our concern as wikipedians. Our concern is that the overall text in the caption (I am not talking about the phrase "black swans exist") should be verifiable in secondary sources, but it is not and therefore we must put back the {{cn}} tag. However, a better solution would be to remove the sentence that cannot be verified, because the {{cn}} tag has been there for quite a long time and no one provided a source. I am pretty sure that no one can provide a source. It is so much in contradiction with secondary sources. It is clearly not verifiable. Again, please, please, read me carefully when I say that I am not talking about the phrase "black swans exist". You keep referring to this phrase, but I am NOT adding the tag because of this phrase. It is the overall text that is not verifiable. --Dominic Mayers (talk) 16:56, 20 December 2018 (UTC)

Yes, yes, so you keep saying - but that is not what you actually did. What you actually did was place a tag on the statement "All swans are white" can be proven false and is, hence, a falsifiable statement, since evidence of black swans proves it to be false and such evidence can be provided. You may think you did something else, but you didn't. I'm a little surprised actually that you haven't noticed the obvious answer, and suggested relocating the tag to a different part of the caption or article. I guess your mind is too highly trained, Majikthise. Chaheel Riens (talk) 17:31, 20 December 2018 (UTC)

Yes, yes, but this sentence is NOT the phrase "black swans exist" and it is exactly the sentence that says something about falsifiability that is not verifiable. The {{cn}} tag was deserved. But, you would be right, if you were to say that it has been there for quite a long time and one must be bold and remove sentences that are not verifiable. --Dominic Mayers (talk) 18:21, 20 December 2018 (UTC)

What's the point of the controversies section?

The current outline is:

8.1 Economics

8.2 Evolution

8.3 Young-earth creationism

8.4 Historicism

8.5 Mathematics

Seems kind of a grab bag. You have three disciplines that arguably have different standards of truth than science (Economics, History, and Mathematics) and two theories where falsifiability can be applied. I'd propose dropping the theories and reworking the section into an exploration of the applicability and inapplicability of falsification to other disciplines. - GretLomborg (talk) 15:35, 27 March 2019 (UTC)