A meta question. About applying a theory to itself. Can Popper's theory (methodology) of falsification be applied to his own work?

Suppose we found evidence that science advances by adopting non-falsifiable statements, wouldn't that prove that he was wrong? Maybe the statements themselves are not scientific, according to his standards, but maybe for the ones making the statement they are.

  • 2
    No; Popper's theory is not a scientific theory. Jul 11, 2021 at 15:34
  • @MauroALLEGRANZA So he could be wrong or he could be right. That is indeed no science. It is more a belief system.
    – user53163
    Jul 11, 2021 at 15:36
  • It is philosophy... And everyone everywhere could be wrong or could be right; also science. We are human... Jul 11, 2021 at 15:37
  • @MauroALLEGRANZA And luckily! But Popper philosophizes as he has found an extra-scientific fact about the sciences. A fact that I think is wrong.
    – user53163
    Jul 11, 2021 at 15:41
  • think the elephant in the room is whether we can call astrology a philosophical theory @MauroALLEGRANZA I very much doubt many people think it's a scientific fact anyway. I'm guessing the question is just as much whether popper's theory could be pseudo science, as whether it is not
    – user61970
    Jul 29, 2022 at 21:22

4 Answers 4


Popper's theories are part of the philosophical literature — a philosophy of science — not scientific works in their own right. Simple put, Popper's theories are not empirical studies; they are exercises in reasoned analysis as part of an effort to build a cohesive and coherent understanding of the nature of the activities we call 'science'. It's best to think of Popper as outlining a 'scientific ethic': a formula for how scientists ought to do their work, not a description of how they do do their work.

Yes, many people have argued that scientists do not think or act the way Popper suggests. That has had no more impact on Popperism than the idea that people don't regularly behave morally has had on Christianity.

The problem with Popper's theorizing is that he did not produce a coherent or consistent ethical framework. It was an interesting approach in its day (particularly in its proper role as an evolute of logical positivism), but it never got a proper handle on the demarkation issue — failing to properly distinguish between non-science, failed science, pseudoscience, and protocol-science — and never created a workable framework for those who wished to pursue science.  


Yes, absolutely.

Popper developed a demarcation between science and pseudo-science, but he did not consider there to be a hard line between philosophy and science. Sciences instead were an outgrowth, a refinement, of particular specialty subjects within philosophy.

Therefore, the principle of falsification testing is one Popper himself applied vigorously to philosophy. Much of his own falsification work was aimed at logical positivism, and Popper was ultimately successful in replacing Positivism as the method of philosophy of science. He also worked to falsify materialist views of mind and of abstract objects -- reviving Frege's three world triplism as an alternative ontology.

Popper recognized the importance of taking the critiques of his own thinking seriously, devoted considerable effort in his later life to trying to address weaknesses other philosophers pointed out.

Notably, both Kuhn and Quine tested Popper's model, and found falsifications of it. Kuhn by noting the sociology of scientists does not follow Popper's model, and Quine by noting that falsification is impossible in principle, due to theory being underdetermined by evidence (all theories are infinitely patchable). Also, actual scientists do not abandon a theory at the first falsification, but instead modify one of its secondary associated assumptions. Popper's claim of science steadily approaching "truth", the principle of Versimilitude, was also shown to be computationally unstable.

In response to Quine, Popper recast falsification, to use a modified version of Occams Razor. Rather than simplicity, his version of Occam preferences the "more predictively powerful" of alternative theories that fit data. As the kluges that Quine's theorizing reveals are predictively weak, this pragmatic/modified version of falsification can replace the absolute one Popper had initially advocated for.

In response to scientists not abandoning theories when challenges are encountered, Popper constructed a theory of primary claims, and secondary assumptions. When the secondary assumptions get too kluged up, the primary theory loses its predictive power, thus falsification tests can, as they accumulate, lead to effective falsification of a theory.

Vs Kuhn, the consensus view is that Popper was articulating how science should be done, but scientists are human, so Kuhn was uncovering the irrational sociology among scientists.

This "testing" of Popper's claims -- lead to Popper eventually adopting more and more a pragmatic rather than analytical/logical approach to truth. His science approach is not ABSOLUTELY true, but with its pragmatic tweaks, it describes very well what scientists should do, and what they generally claim to be doing.

  • so what's the difference between pseudo science and philosophy?
    – user61970
    Jul 29, 2022 at 21:30
  • Philosophy in the broad sense is pursuit of knowledge. Sciences, arts and humanities are subsets of that. In its narrow sense it is those knowledge issues we have not been able to characterize well enough to spin off yet as their own separate discipline.
    – Dcleve
    Jul 30, 2022 at 0:02
  • Pseudo science are those agendas or research programs which claim the mantle of science, but which structure their claims and methodologies so as to avoid or evade possible refutation testing.
    – Dcleve
    Jul 30, 2022 at 0:04
  • hmm. I get what you mean, but it's a little vague to say that people claim astrology is a science.
    – user61970
    Jul 30, 2022 at 0:14
  • @unknown_user_a The principles of astrology can be implemented as either falsifiable or non falsifiable. Depends on the astrologers approach. But few astrologers claim to be scientific. It would only pseudoscience if they make that claim and then use the more common non falsifiable approach
    – Dcleve
    Jul 30, 2022 at 1:30

xkcd: fields arranged by purity plus epistemological hilospgers and nihilists Extended from the original XKCD comic strip, which is in the frame.

I argue here that science is, what scientists do, as bound by the values of their community: Can one speak unambiguously of "The" Scientific Method?

Scientific knowledge is tentative, and I see trying to use Falsifiability on itself as implicitly taking a Foundationalist view of knowledge, the idea of an ultimate grounding of knowledge. But first that assumption hasn't been justified, and second it runs into insoluble contradictions: Does the first Godel's incompleteness theorem forbids the existence of a Theory of Everything?

I like David Deutsch picture in The Fabric of Reality, that when we try to assemble a picture of how we explain the world we need multiple modes of thinking. Briefly discussed here: Is it the job of physics to explain consciousness?


In principle, yes. The core of Popper's philosophy is that scientific results, scientific theories must be falsifiable. If they do not conform to this standard then it is no viable scientific theory.

This means that you simply have to find a theory that is not falsifiable.

You can say that these are not real scientific theories precisely because they do not conform to the standard of Popper, but then you overlook the fact that they are used by actual scientists.

  • The argument isn't that not falsifiable theories could exist or couldn't be used by scientists, it's that they would be science, but pseudo-science.
    – haxor789
    Jun 29, 2022 at 11:23
  • Even if we ignore how they are accepted by scientists as science and are involved with progress in the sciences (i.e. you happily bow to Popper's demarcation - whatever status it has - over the actual history of science), you seem to think that what makes a theory "pseudo science" is it being non-falsifiable and used by scientists. But there is no science of astrology: and you don't have to believe it could be science to consider it "pseudo science" @haxor789
    – user61970
    Jul 29, 2022 at 21:17
  • @unknown_user_a What exactly is your point here? I mean scientists are humans and as such they can do science and pseudo-science and whatever else. There's quite a few who probably believe science is what people in white lab coats do... Though what if something is non-falsifiable you basically state that it is true regardless of what evidence does or could show. So if it tries to masquerade as science but isn't bound to the description of the real world, then it would be a pseudo-science.
    – haxor789
    Jul 29, 2022 at 22:45
  • the question is why isn't Popper's theory a pseudo science? what's not to get with that?
    – user61970
    Jul 29, 2022 at 23:21
  • Because it's not a science and doesn't claim to be, does it?
    – haxor789
    Jul 30, 2022 at 12:16

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