Logical positivism was one of the things Popper was responding to. The Vienna Circle were mainly active between the wars, and A J. Ayer published Language, Truth and Logic in 1936. And positivism in the broad sense of ‘a philosophical system recognizing only that which can be scientifically verified or which is capable of logical or mathematical proof, and therefore rejecting metaphysics and theism’ is still highly influential even if only tacit much of the time.

Logical positivism was one of the things Popper was responding to. The Vienna Circle were mainly active between the wars, and A J. Ayer published Language, Truth and Logic in 1936. And positivism in the broad sense of ‘a philosophical system recognizing only that which can be scientifically verified or which is capable of logical or mathematical proof, and therefore rejecting metaphysics and theism’ is still highly influential even if only tacit much of the time. — Wayfarer

My impression was that logical positivism died with the Vienna Circle dismantlement. Do you know any sources for current logical positivists? I know of neo-Fregelians, two dimensionalists, and Kripe?

As I said, a lot of positivism is tacit - it’s not defended as a formal philosophy but is implicit.

It’s worth recalling who invented the term ‘positivism’ and why - it was Auguste Comte, who founded sociology. Positivism was a form of historicism, i.e. culture evolved through progressive stages, beginning with animism, then monotheism, metaphysics, and then culminating in the emergence into the sunlit uplands of science. And though they don’t use the terminology, it is clearly visible in nearly all the writings of the scientific atheism of Dawkins, Dennett, Pinker, and others of that ilk. In that sense, positivism remains one of the predominant influences on scientific-secular thinking.

As I said, a lot of positivism is tacit - it’s not defended as a formal philosophy but is implicit.

It’s worth recalling who invented the term ‘positivism’ and why - it was Auguste Comte, who founded sociology. Positivism was a form of historicism, i.e. culture evolved through progressive stages, beginning with animism, then monotheism, metaphysics, and then culminating in the emergence into the sunlit uplands of science. And though they don’t use the terminology, it is clearly visible in nearly all the writings of the scientific atheism of Dawkins, Dennett, Pinker, and others of that ilk. In that sense, positivism remains one of the predominant influences on scientific-secular thinking. — Wayfarer

Thanks for educating on the current landscape of scientific thought.

Worth a read :wink:

//particularly the last sentence.//

Are you asking how they could have missed the Popperian insight that scientific theories are never verified, but are merely held to be true until and unless they are falsified, or something else?

Are you asking how they could have missed the Popperian insight that scientific theories are never verified, but are merely falsified, or something else? — Janus

Yes, that's what I'm asking. And hence why Wittgenstein rejected the logical positivists with his version of the falsifiable principle implicit in the Principle of Bivalence.

Of course this insight may be found already implicit in Hume and explicit in Peirce. I'm not familiar with the 'Principle of Bivalence' so I can't see how it might relate to the notion of falsification.

Of course this insight may be found already implicit in Hume and explicit in Peirce. I'm not familiar with the 'Principle of Bivalence' so I can't see how it might relate to the notion of falsification. — Janus

The Principle of Bipolairty, states that anything that can be, can be otherwise.

I'm not too sure what that could mean. My understanding of falsification is not that something is first true and then becomes false, for example.

I'm not too sure what that could mean. — Janus

Show me where I lost you.

I can think of a couple of ways that something that is one way could be otherwise; one to do with actuality and the other to do with logical possibility. In terms of actuality something could change and become something it previously was not. In terms of possibility, something could have been other than it is.

I am not seeing how either of these relate to falsifiability, at least as Popper, according to my understanding, conceived it..

I can think of a couple of ways that something that is one way could be otherwise; one to do with actuality and the other to do with logical possibility. In terms of actuality something could change and become something it previously was not. In terms of possibility, something could have been other than it is.

I am not seeing how either of these relate to falsifiability, at least as Popper, according to my understanding, conceived it.. — Janus

Yes, that is under the guise that you believe in metaphysical necessity and determinism.

Interesting to note also that in the current disputes over 'string theory', doubts are being cast on the validity of falsifiability. So much so, that the string theory protagonists refer to those demanding falsifiability as 'the popperazi'.

Sorry Posty, but I can't see what "metaphysical necessity and determinism" has to do with it, and I am still no clearer as to how this relates to Popperian falsification.

I think the principle of falsifiability has long been held to be, at least in some quarters, unsustainable. It's a logical problem insofar as to falsify something is logically equivalent to verifying its negation.

Sorry, I must have made that up. My apologies.

No need to apologize, Posty, you must have had something in mind. Even if it were nonsense it's good to get it out there for examination. Remember Wittgenstein's aphorism: “Don’t for heaven’s sake, be afraid of talking nonsense! But you must pay attention to your nonsense.”

Well, if you insist, then what I had in mind is that the Principle of Bipolarity, only applies to contingent truths, but the more I think about it, why not necessary ones too?

I think the ‘principle of falsifiability’ is a perfectly sound idea - it simply says, if you can’t test a theory against empirical observation, then it’s not a scientific hypothesis. Can’t see anything the matter with it.

In respect of current speculative physics, the critics of string theory are saying that no conceivable result could falsify the theory, as the ‘strings’ themselves are forever out of scope for empirical investigation, and if there are other universes, then so too are they.

I was reflecting the other day on the fact that the oft-quoted phrase ‘how many angels can dance on the head of a pin’ actually started from a debate about whether two angelic intelligences could occupy the same location - which has resonances with the whole debate over the meaning of superposition in physics. ‘plus ça change, plus c'est la même chose’ :-)

In respect of current speculative physics, the critics of string theory are saying that no conceivable result could falsify the theory, as the ‘strings’ themselves are forever out of scope for empirical investigation, and if there are other universes, then so too are they. — Wayfarer

Not to quibble, but I'm not sure it's correct to say that no conceivable result could falsify (or verify) string theory: it's just that the energy levels needed to test the theory may well be forever out of reach of practical implementation. So, string theory may be unfalsifiable in practice, though not in principle.

Having said that, nothing in my post should be construed as a defense or condemnation of the content of string theory or any variant thereof, which I take no position on, mostly because I'm grossly unqualified to do so. I just wanted to point out that there's a relevant distinction between a theory's being untestable in (current) practice and untestable in principle. The latter seems a much more dire state of affairs for an ostensibly scientific theory.

I do understand how difficult it is to fathom current mathematical physics (although discovered a useful PBS video series on ‘strings’ yesterday.) But as I understand it, the argument is indeed about whether string theory can ever be testable, under any energies.

One of the key papers in the argument was by George Ellis and Joe Silk, Defend the Integrity of Scientific Method, which starts:

This year (2014), debates in physics circles took a worrying turn. Faced with difficulties in applying fundamental theories to the observed Universe, some researchers called for a change in how theoretical physics is done. They began to argue — explicitly — that if a theory is sufficiently elegant and explanatory, it need not be tested experimentally, breaking with centuries of philosophical tradition of defining scientific knowledge as empirical. We disagree. As the philosopher of science Karl Popper argued: a theory must be falsifiable to be scientific.

The sceptics include Silk and Ellis, Peter Woit (‘Not Even Wrong’), Lee Smolin (‘The Trouble with Physics’) and now Sabine Hossfielder (‘Lost in Math’. )

There seems to be an emerging consensus that supersymmetry is not going to be validated - it was supposed to have been found by the LHC by now and there’s no sign of it. There is an undercurrent of physics being ‘in crisis’. Maybe it will turn out that at the end of the day, matter is unintelligible.