Banning the terms "realist" & "anti-realist" -- do you agree?

[lucas_]

Tim Maudhin in his excellent book "Philosophy of Physics: Quantum Theory" suggests we must ban the terms "realist", "antirealist", do you agree?

Quoting these critical passages in the Introduction part of his very thick book:

"It has become almost de rigueur in the quantum foundations literature to systematically misuse the terms “realist,” “realistic,” “antirealist,” and “antirealistic.” These terms have a precise meaning in the philosophy of science, a meaning that seems to be completely unfamiliar to most physicists. And it is not just that these physicists misuse these terms, it is rather that they simply toss them around with no attached meaning at all. This has had terrible consequences for discussions in foundations of quantum theory. In the proper meaning of the term, physical theories are neither realist nor antirealist. That is, as we used to say, a category mistake. It is a person’s attitude toward a physical theory that is either realist or antirealist. <snipped a part>

The scientific realist maintains that in at least some cases, we have good evidential reasons to accept theories or theoretical claims as true, or approximately true, or on- the- road- to- truth. The scientific antirealist denies this. These attitudes come in degrees: You can be a mild, medium, or strong scientific realist and similarly a mild, medium, or strong scientific antirealist. Ultimately, this is a question addressed by epistemology and confirmation theory. But this book is not about either epistemology or confirmation theory, so the issue of whether one should be a scientific realist or antirealist, and to what degree, is never even broached. Like “Copenhagen Interpretation,” the very terms “realist” and “antirealist” do not appear outside this Introduction.

The real damage that has been done by misapplying the term “realist” to theories rather than to people’s attitude toward theories is raising false hopes. For example, we will see that Bell’s theorem, together with reported data, rules out the possibility of any empirically adequate physical theory that is local in a precise sense of the term “local.” The Pusey, Barrett, and Rudolph (PBR) theorem, together with data that matches the predictions of quantum theory, rules out the possibility of any empirically adequate “psiepistemic” physical theory. But often, when reporting these crucial results, the term “realist” or “realistic” is snuck in. Bell, we are told, ruled out all local realistic theories, for example. And that locution strongly suggests that one can avoid nonlocality and evade Bell’s result by saying that realism is what ought to be abandoned. But this suggestion is nonsensical. Bell proves that no local theory, full stop, can predict violations of his inequality. Whether some person’s attitude toward the theory is one of scientific realism or not is neither here nor there. If I had my druthers, “realist” and “anti- realist” would be banned from these foundational discussions. And in my own book, I have my druthers, so I will not mention these terms again.

If you don't believe him that "realism", "antirealism" are nonsensical, why?

If you believe him, why also?

 

[vanhees71]

Yes, I'd ban these terms from any hard (natural or structural) science discussion since they have been blurred by philosophers to an extent that they don't have any meaning or clear definition being subject to mathemtical analysis and observational objective investigation anymore.

 

[lucas_]

Yes, I'd ban these terms from any hard (natural or structural) science discussion since they have been blurred by philosophers to an extent that they don't have any meaning or clear definition being subject to mathemtical analysis and observational objective investigation anymore.

Lest we misunderstood. Tim Mauldin book is not supporting the side of vanheez71, in fact he just devoted one and half page to vanheez71 positions. The following passage is still part of his introduction (his book is so unique and recommended reading.. imagine such gems already in the introduction only. Just read the rest of his book and you will rewarded with many insights):

By far the most controversial aspect of this book is not what it contains but what it omits. There is detailed discussion of the Ghirardi- Rimini- Weber spontaneous collapse theory, of the pilot wave theory of the Louis DeBroglie and David Bohm, and of Hugh Everett’s Many Worlds theory. But there is no discussion— indeed aside from here no mention— of the most famous “interpretation” of quantum theory of all: the Copenhagen Interpretation ascribed to Niels Bohr and his colleagues. Why is that?

A physical theory should clearly and forthrightly address two fundamental questions: what there is, and what it does. The answer to the first question is provided by the ontology of the theory, and the answer to the second by its dynamics. The ontology should have a sharp mathematical description, and the dynamics should be implemented by precise equations describing how the ontology will, or might, evolve. All three of the theories we will examine meet these demands.

The Copenhagen Interpretation, in contrast, does not. There is little agreement about just what this approach to quantum theory postulates to actually exist or how the dynamics can be unambiguously formulated. Nowadays, the term is often used as shorthand for a general instrumentalism that treats the mathematical apparatus of the theory as merely a predictive device, uncommitted to any ontology or dynamics at all. That predictive device is described in Chapter 2 under the moniker “the quantum recipe.” Sometimes, accepting the Copenhagen Interpretation is understood as the decision simply to use the quantum recipe without further question: Shut up and calculate. Such an attitude rejects the aspiration to provide a physical theory, as defined above, at all. Hence it is not even in the running for a description of the physical world and what it does. More specific criticisms could be raised against this legacy of Bohr, but our time is better spent presenting what is clear than decrying what is obscure.1

Besides rejecting the usual terminology of “quantum theory” versus “interpretation of quantum theory” in favor of “predictive recipe” versus “physical theory,” and besides ignoring the historical question of what (if anything) should count as the Copenhagen
Interpretation, this book differs from most standard discussions in a third way.

The third way is the realist, antirealist label. So my questions about whether we should ban "realist", "antirealist" concept is addressed for those non-vanheezist folks here who want a physical theory and not just contented with predictive recipe.

 

[akvadrako]

I think the fact that @vanhees71 and as Maudhin says, many other physicists, use realist to mean something different than what philopsophers of physics would use, is a good enough reason to not use them. Probably the same thing applies to local.

 

[vanhees71]

Well, it might be a good book, but oviously from the cited text it rather discusses the more esoterical spectrum of "interpretations" than the one which is really used by physicists interested to understand observed natural phenomena rather than philosophical quibbles with no relation to what's objectively observed, and that's the minimal interpretation.

There's some appeal of Bohmian mechanics, but it doesn't provide anything in addition to the minimal interpretation concerning phenomena and it's not (yet?) formulated in a satisfactorial way for relativistic QFT.

Many worlds has the appealing feature to just deny the assumption of a "collapse", which makes no sense at all given relativsitic causality structure of spacetime, and it's not needed.

Then there are the approaches going beyond just reinterpreting QT but extending it in the one or the other way, like GRW. This are much more attractive to my taste, because they can be tested against QT, at least in principle, in some way. Whether or not there's this "spontaneous collapse" of not is thus a question that can be decided experimentally and thus is a good scientific theory in contradistinction to all the "interpretations" of QT which don't provide anything in addition to the minimal interpretation than just the apparent solution of some quibbles of philosophers based on the prejudices about how nature should behave just than just realizing what can be objectively observed and described by QT about how she actually does.

 

[DarMM]

I think representational and non-representational are better. Non-Realist makes it sound like one is claiming things don't exist.

 

[A. Neumaier]

Tim Maudhin in his excellent book "Philosophy of Physics: Quantum Theory" suggests we must ban the terms "realist", "antirealist", do you agree?

If you don't believe him that "realism", "antirealism" are nonsensical, why?

If you believe him, why also?

It is antirealist (un-realist-ic) that he gets through with his wish for banning the term. For realists, the term 'realist' has a useful meaning.

 

[kurt101]

To me a realistic theory is a theory that can be simulated (like on a computer) and can conceptually reproduce every phenomena that we observe. I would describe someone who is anti-realist as someone who believes there is something beyond our ability to reason that prevents us from being able to do this.

 

[DrChinese]

Maudlin: "These terms have a precise meaning in the philosophy of science, a meaning that seems to be completely unfamiliar to most physicists."

I appreciate the issue he raises. But in fairness, no group gets a monopoly on a word like "realism" and I certainly deny that the usage Maudlin references is somehow superior to any other. You could just as easily recommend banning the word "light" from discussions of science as being ambiguous.

Within the context of any discussion of Bell, EPR, or entanglement, "realism" has a particular meaning that can be properly parsed. It certainly has nothing to do with scientific realism as Maudlin references. Yes, "realism" can be a little confusing when discussing Bell. Below are phrases that are often used as synonyms instead. Please note that switching to these does not make the discussions much easier, and many object to the substitution on the grounds that the synonyms are not exact substitutes:

Frequent synonyms of "realism":
- Hidden variable (probably most frequently substituted)
- Elements of reality (from EPR, the early source of the usage)
- Objective reality (as compared to subjective reality)
- Non-contextual (a better descriptor in many ways, but often becomes confusing in sentences)
- Determinism (straying a bit)

So I don't think "banning" a particular variation has any benefit other than to those who aren't discussing Bell or entanglement anyway.

 

[PeterDonis]

Tim Maudhin in his excellent book "Philosophy of Physics: Quantum Theory" suggests we must ban the terms "realist", "antirealist", do you agree?

His argument is not actually an argument for banning the specific terms "realist" and "anti-realist", it's a general argument for banning terms in scientific discussions that don't have precise scientific meanings. "Realist" and "anti-realist" are by no means the only terms that are thrown around in discussions without precise meanings; but they also can have precise meanings. So I think the best response is not to "ban" particular terms, but to require precise meanings for terms.

 

[Morbert]

I suspect Maudlin's distaste for "realist" when applied to a theory is due to his requirements for an exemplary theory.

A physical theory should clearly and forthrightly address two fundamental questions: what there is, and what it does.

An antirealist account of QM might not address the first question, insofar as it might not offer a formulation in terms of beables. Maudlin would probably prefer these "observables-only" accounts to be delegitimised rather than categorised as antirealist.

He might have a point about ambiguity of the terms, but I wouldn't be in favour of eliminating any vocabulary just to stack the deck against some accounts of QM.

 

[A. Neumaier]

"Realist" and "anti-realist" are by no means the only terms that are thrown around in discussions without precise meanings; but they also can have precise meanings. So I think the best response is not to "ban" particular terms, but to require precise meanings for terms.

One needs precision both on the level of the theory and on the level of the practical application.

'Measurement' and 'measurement results' are most in need to be made precise on the theoretical level.