As we have been discussing ontology as it refers to hidden variables and multiple worlds, I thought there might be some interest in this excerpt from my Hall book, The Roots of Representationism. It focuses on a shift in Quine’s position subsequent to “On What There Is,” but I think it touches on some of the broader questions of ontology and how one ought to investigate it as well.
Postscript on Quine, Alston and Hall on Ontological Commitment
As one might infer from the foregoing, Hall takes the unearthing of the ontological commitments imbedded in philosophical theories to be a tricky, nuanced undertaking. There will generally be found overlaps and lacunae in the evidence (the relevant philosophical statements), and some of this material may require careful interpretation. That position is in stark contrast to Quine’s early pronouncements on this subject, where it seemed one could just look for quantifiers and read off their ranges. Let us therefore pause a moment in our exposition of Hallian categories to explore this difference in approach. In his seminal 1948 paper, “On What There Is,” Quine continued the assault on Meinongian beings that began with Russell’s Theory of Descriptions by arguing that proper names could be converted to definite descriptions and handled in just the way Russell dealt with “the present king of France.” That is, on Quine’s view, finding what seems to be a proper name in some theory doesn’t demonstrate that the theory is committed to entities referred to by that name. Thus far, Hall would agree: the simple search for proper names can only be the beginning of a credible ontological analysis of any philosophical (or scientific or ordinary language) writing. But Quine goes on to claim that if one can “paraphrase away” sentences containing any name “N,” then we need not countenance any such items as might have been thought to be named by “N.” Thus, because one has used sentences containing the word “Pegasus,” it doesn’t follow that one can be accused of (even unwillingly) countenancing flying horses, so long as a good paraphrase is available. In particular, there is no danger to one’s sense of philosophical
parsimony created just by asserting things like “Pegasus doesn’t exist.” Quine (1948 [1953]: 8) put it this way:
[T]he singular noun in question can always be expanded into a singular description, trivially or otherwise, and then analyzed out a la Russell. We commit ourselves to an ontology containing numbers when we say there are prime numbers larger than a million; we commit ourselves to an ontology containing centaurs when we say there are centaurs; and we commit ourselves to an ontology containing Pegasus when we say Pegasus is. But we do not commit ourselves to an ontology containing Pegasus or the author of Waverley or [a round square] cupola when we say that Pegasus or the author of Waverley or the cupola in question is not. We can very easily involve ourselves in ontological commitments by saying, for example, that there is something (bound variable) which red houses and sunsets have in common; or that there is something which is a prime number larger than a million. But this is, essentially, the only way we can involve ourselves in ontological commitments: by our use of bound variables.
On this point, Hall demurred; he was not convinced either that the matter was so simple as Quine claimed or that there is anything terribly special about “There are…” or “Some…” statements. He was not alone in taking this tack. For example, William Alston in his little 1957 paper, “Ontological Commitments” pointed out that
[W]hether a man admits (asserts) the existence of possibilities depends on what statement he makes, not on what sentence he uses to make that statement. One admits that possibilities exist whenever he assertorially utters `There is a possibility that James will come’ or any other sentence which means the same (would ordinarily be used to make the same statement.) It is a question of what he says not of how he says it. Hence he cannot repudiate his admission by simply changing his words. A man who was afraid of policemen would be reassured if he were convinced that there are no policemen. But he would not be reassured if he were convinced that one could express all one’s beliefs in a language which took not policemen, but rather policemanship, as values of variables…. (1957: 13)
Hall (1960: 32) attacks from a similar angle. He argues that an absolute idealist such as F.H. Bradley was committed to his Absolute whether or not this commitment could be found either in any quantifier binding a variable or in the range of any acceptable variables. Bradley simply took Reality-as-a-whole to be the implicit subject of every assertion and gave it the proper name “The Absolute.” It seemed to Hall that if that was not a clear case of ontological commitment to some putative entity, nothing ever could be. Thus, any insistence by Quine in 1948 to the effect that “The Absolute” in Appearance and Reality is eliminable has no bearing whatever on an assessment of Bradley’s ontological commitments. Beliefs may not be justly ignored just because they are not put in some particular way. For Hall, all the resources of language must be investigated to determine ontological commitment. In fact, Hall notes that if we could rest with the simple search for quantifiers, we might find that “while Dickens was not committed to the real existence of Pickwick, he was committed to several of Mr. Pickwick’s friends because he quantified over them.” (Hall, 1960: 34)
Furthermore, even the proto-positivist Wittgenstein of the Tractatus held that logical propositions show or present the “scaffolding of the world.” “They presuppose that names have meaning, and that elementary propositions have sense.” (6.124) And such logical features of our language cannot somehow be undone by translation of sentences into a formal mode. We can try, as Carnap (1937: 308) did try, to treat metaphysical assertions as “disguised” syntactical statements, but if “by a transposed mode of speech we mean one in which in order to assert something about an object a, something corresponding is asserted about a [linguistic] object b which stands in a certain relation to the object a” we will be stuck trying to explain the nature of this “certain relation.” As Hall put it, “A correlation is a correlation; every wife has a husband, but to say that she is her husband is indeed beyond the proprieties even of a male-dominated society.” (1959: 56) One running from the law is likely to be no more comforted by “In English, the noun ‘Policeman’ is used for the object over there.” than he would be by “Don’t worry, there are no particular policemen around, only a few exemplifications of policemanship.” For good or ill, ontology does not recapitulate any philology that’s largely a matter of the translation of apparently referring terms into apparently non-referring idioms.
As far as I know, Quine didn’t specifically respond to either Hall or Alston on this matter (although he does mention the Alston paper a couple of times in Word and Object). But by the publication of his 1966 paper “Existence and Quantification” he had altered his thesis significantly. In this later work he writes, “To show that a theory assumes a given object, or objects of a given class, we have to show that the theory would be false if that object did not exist, or if that class were empty; hence that the theory requires that object, or members of that class in order to be true.” (Quine, 1966 [1967]: 93) And, while he still gives significant weight to particular locutions, he now acknowledges that such statements as “There are unicorns” may be misleading:
Thus far I have been playing down the difference between commonsense existence statements, as of rabbits and unicorns and philosophical existence statements, as of numbers and attributes. But there is also a curious difference between commonsense existence statements and philosophical ones that needs to be played up, and it is one that can be appreciated already right in among the rabbits. For let us reflect that a theory might accommodate all rabbit data and yet admit as values of its variables no rabbits or other bodies but only qualities, times, and places. The adherents of that theory…would have a sentence which, as a whole, had the same stimulus meaning as our sentence “There is a rabbit in the yard”; yet in the quantificational sense of the words they would have to deny that there is a rabbit in the yard or anywhere else.…When we…tell him there is a rabbit in the yard, he will know better than to demur on account of his theory; he will acquiesce on account of a known holophrastic relation of stimulus synonymy between our sentence and some sentence geared to his different universe. In practice he will even stoop to our idiom himself, both to facilitate communication and because of speech habits lingering from his own benighted youth. This he will do when the theoretical question is not at issue, just as we speak of the sun as rising….I grant that there are for him two senses of existence; but there is no confusion and the theoretical use is rather to be respected as literal and basic than deplored as a philosophical disorder. Similar remarks apply to our nominalist. He will agree that there are primes between 10 and 20, when we are talking arithmetic and not philosophy. When we turn to philosophy he will condone that usage as a mere manner of speaking, and offer the paraphrase. Similar remarks apply to us; many of our casual remarks in the “there are” form would want dusting up when our thoughts turn seriously ontological. Each time, if a point is made of it, the burden is of course on us to paraphrase or retract. (1966 [1967]: 98-99)
I believe this to be a particularly clear statement by Quine of a Hallian distinction between empirical and categorial assertions. It shows why, (to use Hall’s example) the fact that a Hegelian’s references to “The Absolute” can be paraphrased into language that does not seem on its face to require any such thing(s) does not entail that Hegelians would or should change their beliefs regarding what there is—even if they concur with the grammaticality of the restatement. Similarly, if a Quinian materialist allows proper names for various bodies or theoretical entities in his theory that an immaterialist finds she can paraphrase entirely into property talk, such paraphrasis need not move this materialist to endorse properties and dispense with muons. In fact, the Quinian’s reasons for resisting such a conversion would likely have nothing to do with linguistic flexibility at all, but would focus on different matters entirely—parsimony, explanatory value, and criteria of identity to name three. Thus, by 1966, Quine seems to have been in basic agreement
with Hall that to determine somebody’s ontological commitments, the safest course is simply to ask her—whether she is a Platonist, a Bradleyan or a materialist. And, naturally, if one does not have the particular philosopher around to answer this question, one may be required to do considerably more than simply provide the range of the quantifiers in some comprehensive restatement of the theory. An accurate assessment of commitments requires a determination of just which ‘entities’ are such that their non-existence would make the theory false. To return to Dickens, Quine would now be able to say (as he couldn’t in 1948), that no legitimately philosophical bound variable was intended by Dickens when he wrote things like “Some of Pickwick’s friends returned to London.” The upshot is that there’s nothing dispositive about “Some…” or “There are…” statements: philosophical analysis requires one to dig deeper, to investigate the total resources of the language/theory in question.
And what does that have to do with the price of tea in China?
I see all of that as shop talk from within the ivory tower.
The big problem that I see in philosophy, is an over-emphasis on logic. Quine pretty much wants to see everything as logic. The early Wittgenstein had the same problem. The later Wittgenstein seems to have recognized that as a mistake.
Several years ago, I read a paper “There are no ordinary things” by Peter Unger (Synthese 41#2, 1979). I took Unger’s point to be that there are problems with the way philosophers reason with logic. Okay, that was already my opinion before I read that paper.
In retrospect, I think a better title would have been “Ordinary things are not logical objects.” It seems to me that ontology could only makes sense if it were about logical objects.
I guess I could summarize my view as:
Natural language is not a logic expression system.
Natural language statements are not logic propositions.
Ordinary things are not logical objects.
Most logic disagreements are not really disagreements over logic; rather, they are disagreements over assumed premises or disagreements over meanings.
Ontology is pointless.
Epistemology is mostly silly, but it could actually be quite useful if people would dispense with its commitment to logicism.
Just rephrase everything you want to say without using any form of the verb “to be”.
I’m not sure where you got the idea that Quine thought everything was logic. Exactly the opposite is true. He thought logic was ultimately an empirical science. As I don’t know what you mean by phrases like “logic expression system” or who might have ever suggested that natural languages were “logic propositions” I’ll stop there.
Re Unger, I meant to respond to Bruce’s question about whether I saw his recent interview. I did. He’s very cocky. FWIW, I’ve never been blown away by his stuff myself–but he obviously takes a very different view of his talents.
Yes, I saw that. I took it as entertainment. There wasn’t much content.
My impression was that Unger doesn’t actually take himself very seriously.
I thought he was being very serious — serious about getting some publicity so he could sell some books.
I don’t have the expertise to understand or respond to his ideas, so I’d look for the reviews of what he says in the book, not in interviews.
Thanks for taking the time to post this. It will take me some time to understand it, assuming I can.
Any chance of you connecting the dots more explicitly on how it relates the the MW exchange?
This excerpt is about how to tell what one’s ontological commitments are–not what they ought to be. I think it shows that most of us are committed to ordinary stuff–you know tables, grapes, other people. Of course the question with MW is whether we should (also) commit ourselves to an infinity of worlds and, if so why. I’m not in a position to answer those questions–I just wanted to mention some views about what ontological commitment actually involves–the ways in which it does and doesn’t “matter.”
Thanks for the clarification. Before I saw that, I made this attempt at a paraphrase to what you are saying: . Criticisms would certainly help me to follow you better.
After introducing the challenges of determining ontological commitments that Hall saw, the post starts by looking at Quine’s early work in this area. There is a standard problem in philosophy of language: If names refer to things, then how do we deal with names of fictional things, like Pegasus? Aren’t we committing in some sense to their existence when we say the sentence “Pegasus had wings” is true?
Meinong posited a special form of existence (subsistence) to handle this case. But Russell’s work with descriptions enables Quine to take a different approach. Russell worked with descriptions as in “the present king of France is bald” and used predicate logic to replace the descriptions with bound variables instead of descriptions of possibly non-existent entities. Quine said this same approach could be applied to names by first replacing the name with a description.
Quine then said one can determine the ontological commitments of a theory by replacing names in the theory by predicate logic rephrase a la Russell and then looking for “there are” statements. “There are” statements with bound variables imply commitment to existence but “there are no” statements make no such commitment.
But Hall and others said that that analysis won’t be enough to determine ontological commitments: Hall argues that you need a deeper analysis of the theory than simply how it can be translated to predicate logic and bound variables. You summarize this position by saying “Ontology does nor recapitulate the philology of translating apparently referring terms into non referring idioms”(eg predicate logic, as I understand it). In my understanding, this paraphrase says commitments to existence of entities in the theory is not simply a matter of translating it to predicate logic and looking for bound variables.
You then point out that in later writings Quine takes a more nuanced approach and allows that one may use “there are” forms simply for convenience in communication, and not to reflect ontological commitment. You take this as implicit agreement with Hall that there is a distinction between empirical and categorial assertions, the subtleties of which still escape me, but which I roughly understand as between what a theory really is committing to and what syntactic categories are part of its language.
Specifically, one needs investigate what could exist to falsify the theory to understand what a theory is committing to, and not just look at bound variables in a rephrasing using predicate logic. If you are lucky, the proponent of a theory is available to be versus convenience in the use of language for the theory. If not,you work at determining what a theory is committed to.
On the ontological commitments of MW: I’m working through this which may interest you:
A prolegomenon to the ontology of the Everett interpretation
But how are those commitments, “right” in the sense that they are consistent with (an interpretation) of QM. The paper I linked tries to answer that for MW, as I understand it so far (among other things).
Well, yes. I agree with that.
The interview did not persuade me to buy the book.
BruceS,
I think that’s a pretty good job, Bruce.
BruceS,
I don’t understand this question. Ontological commitments are “right” just in case the items one is committed to really exist. So, if there are many worlds of the type described by the many worlds theory, that theory is true and its commitments are right. As very wise Polish logician once said “It’s raining” is true iff it’s raining.
Well? Are the commitments of that theory true? I’m not betting on it, but, as I’ve already conceded, I don’t even know how my can opener works.
BruceS,
Thanks for the link to the Wallace paper, Bruce–I’ll take a look at it. It’s not really in my wheel house, but if I have any comments I’ll post them (with some trepidation).
I did not make my self clear.
If we are committed to the existence of tables and chairs, and we also accept some interpretation of QM which has its own ontology, don’t we have to show that the two are consistent in some sense? That was what I was trying to ask.
As I understand the paper from Wallace I linked to, he sees ordinary objects as emergent due to the structure of the low level components (the micro-ontology) of the MW interpretation. This is not an emergence due simply to aggregation of those micro components but something that depends explicitly on structure and interaction.
The bulk of the paper is addressing what that micro-ontology is. He warns against reifying the wave function (or the configuration space in which it lives). But I need to read it again to understand what he proposes instead.
If you are in the mood for more virtual office hours, I’d appreciate some more information on what Hall means by “empirical versus categorial assertions”. That seems key to his criticism but I don’t understand it in detail.
Another thought: is there a similarity, do you think, between Hall’s criticism and Searle’s Chinese Room thought experiment in the sense that both are trying to show you cannot get semantics from syntax?
Lastly, I have a concern about the use of natural language for the analysis. Analysis of natural language may work for exposing the ontological commitments of philosophy and ordinary speech, but it does not seem to apply to science.
Obviously, to understand physics, you need to work with the math, not some natural language approximation (which is why I think only people with training in both physics and philosophy can do credible metaphysics in this area). But even for higher level sciences like biology or psychology, I believe the science is expressed by static and dynamic models explained by diagrams supplemented by mathematics, with very limited and structured use of natural language.
So how does the type of analysis summarized in your post have a place in speaking to the ontological commitments of a scientific theory?
Empirical assertions are verifiable and may be aided by such tools as microscopes, oscilloscopes, etc. Categorial ones (the term comes from Aristotle) reflect basic, non-verifiable stances–e.g., whether physical objects are “external” or composed of percepts or whether values are “free-floating.” No improvement of scientific devices can help us determine the choice of basic categories. We have only such things as parsimony, comprehensiveness, consistency, etc.– and there can be no proof that those criteria are appropriate.
I don’t think scientific theories should take positions on ontology–those seem to me to be precisely the categorial questions–the ones that in some sense don’t really matter. It shouldn’t matter to physicists, I don’t think, whether direct realism, indirect realism, or phenomenalism is true. And no advancements of science can answer these questions, because they’re a matter of conceptual choices of what to do with the actual data (that science DOES collect). That’s the Hallian picture anyhow. There’s a lot about this in my book (if you happen to have a bunch of cash to blow).
Re Searle’s Chinese Room, Hall took the (kind of strange) position that purely formal syntax was completely empty–in some sense an impossible endeavor. He called it the “lingua-centric predicament” and argued with Carnap about it.
BruceS,
If we are committed to the existence of tables and chairs, and we also accept some interpretation of QM which has its own ontology, don’t we have to show that the two are consistent in some sense?
I think so. As I’ve said here before the best things I’ve seen on that subject are by Amie Thomasson.
Very helpful, thanks.
Agreed, these are questions in philosophy, not science. In fact, my last exchange with WJM was on this very point: he persisted in criticizing science because he claimed it takes a realist position. I made the same point you make — that realism is philosophy, not science — and added that I thought one needed to come to grips with what philosophers had said on the issue of scientific realism to express an informed opinion. But he did seem to agree with that rule for the conversation, so I ended my participation.
Thanks for the reminder about Ordinary Objects. Amazon has an extended excerpt of the relevant chapter on the “rivalry” with science which looked interesting. The excerpt included an extended discussion of Sellars which brought back fond memories of KN.
Even though the book is probably a bit too philosophically technical for me I should give it a chance; it seems to offer a top down perspective on the same questions which Wallace is taking bottom up.
Thanks again for posting some philosophy on TSZ.
Well, like the color/colour stuff and the motivation for science, that was intended as humor. I’ll take your reply in the same vein.
It seems this post of Walt prompted to you post a quite extended rant, if you don’t mind me using that word, whereas the previous one elicited just one line (on your rejection of all extant QM interpretations). I am guessing you have much stronger feelings against philosophy than against QM, but I am not sure why.
I suppose it is frustration.
There’s a rigidity in the way that philosophy looks at everything.
Based on your first post in this thread, I understand your reference to rigidity as complaining that philosophy relies too much on logic.
But what is there for philosophy to use without becoming something else?
If it includes empirical analysis, then doing that correctly is science. (And I understand Quine thought epistemology should do exactly that, ie be replaced by psychology).
It could try a purely first person perspective to avoid being science and I guess that is what a lot of continental philosophy is. I don’t know much about that aspect.
Or if it could formalize its concepts and processes fully while still remaining non-empirical, then it would be mathematics.
So I think it is stuck with using logic.
In fact, you could interpret this post as being about the limitations of philosophical analysis given that predicament. I doubt that is the way Walt meant it, but it does allow me to claim I am still on topic!
The problem isn’t that logic is rigid. The problem is that logic is too limiting. So, in order to use logic, philosophers have to make additional assumptions — I suppose that’s what metaphysics is really all about. And the rigidity of those assumptions are a problem.
Geometry. No, I don’t mean that high school Euclidean geometry class. I mean the ideas behind it. Ideas such as continuity, connectedness, etc, and methods related to those ideas.
Philosophy can leave the actual empirical science to the scientists. But they could be examining the use of geometric ideas within science.
Try a google search for the Bolzano Weierstrass method of big game hunting. That was originally mathematical humor. But it illustrates the use of geometric ideas to solve problems.
What sort of assumption do you mean?
I recall you complaining about epistemology relying on “justified true belief” to define knowledge. Is that the sort of assumption you mean?
That seems to me to require to much rigor to be useful in bare philosophy. For example, I recall you questioning the use of “converge” in a paper KN mentioned which justifies scientific realism by claiming that theories converge. But could you make that usage mathematically rigorous? Even to meet the topology axioms would seem a challenge, let alone trying to take it further by (say) defining a metric. (Thanks for the excuse to pull out my notes on FA course.!)
On the other hand, maybe you just meant using the ideas informally. But possibly that is what the paper already does (I cannot access it).
To me it makes more for sense for science first to show a branch of math is useful by using it in a successful theory; then philosophers working in an area which is informed by that science would need to understand and use the math.
I think History, Philosophy, and Sociology of Science must do that can of work, eg research how Einstein worked with mathematician collaborators to understand the math he needed to use for GR. But to my original point, I’d see that more as History or Sociology.
Thanks, found it on a page of that kind of obscure humor. Not sure if it could be used in philosophy but maybe in searching a sorted list?
(That was about ideas such as continuity, connectedness, etc)
I’m not expecting philosophy to be concerned with the mathematical rigor. That can be left to the mathematicians.
Mathematicians concern themselves with the rigor.
Scientists actually use these idea, though in a somewhat sloppy manner, leaving the rigor to mathematics.
Philosophy could be (and should be) examining from the big picture view of why these kinds of methods can actually be useful as part of a project for increasing knowledge.
I didn’t question it because I thought that there needed to be more rigor. Rather, I questioned it because I doubt that it could be made to work. If scientific realism requires such convergence, then scientific realism is being unrealistic. The idea that theories need to converge seems to come from a “God’s eye view” way of looking at things.
BruceS,
In the other thread, you asked:
I see that as a good example of a geometric question that philosophers should be addressing.
I’ve come away with several different interpretations of what you would like to see philosophers do to move beyond logic:
1. Independently of any science, philosophers can use topological or other mathematical reasoning to do philosophy. As an illustration, philosophers of mind could invent a topology of qualia. You are not expecting full mathematical rigour, though.
2. Philosophers of science can trace the history of how (a branch of) mathematics can to be used in developing a theory. Similarly, they could analyse how mathematics is used in an existing theory.
3. Philosophers can suggest new mathematical techniques for scientist to use to address some issue. I cannot think of any examples of this; I’d probably call it science if they did so.
4. Philosophers can offer judgement on the appropriateness of a mathematical technique in some branch of science. Maybe the Bayesian versus frequentist approaches to statistical analysis of experiments might qualify as an example of this.
5. Philosophers doing work which is informed by a field of science can use the mathematics of that field when writing philosophy. I believe this is common practice, eg in philosophy of physics. I understand that the leading edge philosophers of physics were educated as physicists first in many cases.
Do any of the above cover what you are getting at?
That was about measurement in the formalism of QM, which is of course right in your wheelhouse: operators and Hilbert spaces.
And if you mean that philosophers should understand that technique and what the use of it in the formalism means for metaphysics, then that is very common with the philosophers I’m familiar with (eg Maudlin, Albert, Wallace).
Or were you referring to something else?
By referring to the lack of a God’s eye view, do you mean that from our limited viewpoint we can never know that theories are converging. Science is fallible and so the current best science could be completely replaced at some point, eg as GR replaced Newtonian gravity.
I believe that’s called the pessimistic induction (“we were wrong then, we are probably wrong now”) Some counter-arguments involve saying that mature sciences do preserve some important quality when they change. For example, the old theory may be an approximation of the new one. Or the new theory may preserve some essential structural elements of the old.
No.
I guess that means that I’m not communicating my point very well.
I missed the implied but unstated “in the formalism of QM.” I see need for philosophy to address the question “What is measurement?”
I’m asking “why should theories ever converge?”
I describe some aspect of the world one way. The Chinese do it a different way. Why would expect those to ever converge? Maybe they are just distinct but similarly effective ways of describing.
But perhaps you want to think of factoring out the syntactic aspects of language, and getting to the semantics (as if that were possible). Quine’s thesis on the indeterminacy of translation points to why that’s unlikely to work.
I see the same issue with scientific theories. How we build a theory is not determined by the nature of the world.
I look at a scientific theory as something like a scaffolding. If you wanted to repair a building, or even just to photograph fine details of the structure, you would erect a scaffolding. But the structure of the scaffolding is vasly under-determined by the structure of the building. We would not expect a sequence of scaffolds to converge. They are just there to do their job.
Take a basketball player, such as Michael Jordan was in his prime years. I very much doubt that Jordan’s brain encoded Newton’s laws of motion. I expect that the brain was handling motion in a completely different way, yet was still able to make excellent predictions.
I’m not an inductionist.
I’m more inclined to say (on the Newton to Einstein switch), that we were not wrong then and we are not wrong now. But our present science does work somewhat better, at least for some problems.
I can take a photo with black and white film. I can take a photo with color film. The results are different. Neither is right and neither is wrong. The black and white film records more detail in variations of contrast, but it misses the color.
There isn’t a single way (a “God’s eye view”) of looking at the world. There are many ways, and we choose between them on a pragmatic basis.
A box rather than a skin.
But I would attempt another metaphor. The ideal physical theory would be a seed from which you could grow things that correspond to experience or measurement.
If you look at mature science, there does not seem to be an issue with underestimation. For example, everyone uses the same QM formalism to work in physics.. So I see underdetermination is more of a theoretical concern than a real one.
Now consider two characterizations of the accepted paradigm theory in some mature science:
1. The theory is part of a sequence which where later elements in the sequence refine and extend earlier elements; these refined/extended elements could be the entities in the theory of the structure of the theory. If the theory is replaced, it is reasonable for this process of refinement and extension to continue.
2. The theory makes a series of novel, unexpected predictions. It would be miraculously improbable for that to have happened simply by accident or by arbitrary choice from set of potential theories that meet the prediction and pragmatic criteria.
Both these characterizations have to be checked empirically, not just asserted or denied.
The scientific realist claims that if those two things are true, then the the structure and/or entities of the theory must tell us something of how the world really is, and not just be arbitrary choices that happen to allow us to make better predictions.
Of course, whether 1 and 2 are true for any theory is an open issue under investigation of philosophers of science. Further, if true, whether that implies with the realist wants it to apply is also disputed. But FWIW, according to this poll, among philosophers Realism is currently dominant (75%).
Here’s a quote from Wallace paper that I linked to earlier that I find amusing; see the last sentence on his view of philosophers versus physicists on this issue.
[…]as David Lewis puts it, the challenge is to “see how [quantum mechanics] looks when it is purged of instrumentalist frivolity and dares to say something not just about pointer readings but about the constitution of the world” (Lewis 1986, p.xi). This is (one way of describing) the infamous quantum measurement problem: to solve the problem is to either make sense of unmodified quantum mechanics as a physical theory in good philosophical standing, or to replace it with some equally-empirically-adequate theory in good standing. (Were this article aimed at a physics audience I would digress for some time as to just why any solution — any move beyond instrumentalist ‘frivolity’ — is needed;
Well, communication is a two way street so I’m missing something too. If you can ever think of an example of what you would like to see more of, than might help me.
On measurement, I understand you to to be saying you think philosophers should try to see if there is some common concept underlying its use across many sciences (eg measuring in QM versus measuring IQ in psychology).
That’s a misunderstanding.
We have a single scientific community. So, of course it is to their advantage to come up with a consistent way of describing things. If we had two independent scientific communities that did not talk to each other, they might very well come up with completely different ways of describing QM phenomena (or other real world phenomena).
Physics uses the mks system. It has taken the metre, the kilogram and the second as basic units. Most physical quantities are described in terms of those. To a mathematician, it seems obvious that we are not required to make those our fundamental entities. We could start with a few completely different entities, and use algebraic combinations of those. A final scientific theory, starting with a different set of basic entities, might not even mention mass, length, time. It would be an entirely different description of the same world.
Our scientific theories are not the world. They are a representation system used to describe the world. The world itself might well be fixed independent of us. But what representation system to use is not thereby determined.
This is the traditional view from philosophy of science. I believe it is largely wrong. Philosophy is a kind of secular religion (the religion of the academy). It is part of the dogma of that religion, that science must be a true description of reality. Why they hold to this dogma, is difficult for me to understand. But that’s the power of tradition and group-think.
By contrast, I see science as a human construct. In particular, a scientific theory is a human construct. Science wants to describe and understand the actual world as well as possible. It does that by forming descriptions, which are representations of the world. So I see a scientific theory as, primarily, a representation system which is capable of carrying those representations. Scientific laws are the protocols which define that representation system.
There’s nothing about a representation system that makes it part of a convergent sequence. For sure, you might be able to extend an existing representation system, so that it can represent more. But there can be times when it is better to do a radical reconstruction. That’s the contrast between Kuhn’s “normal science” and his “revolutionary science,” though Kuhn did not look at scientific theories the way that I do.
The social constructionists look at the obvious evidence for construction of scientific theories, and conclude that science is constructing the world. Kuhn perhaps partly fits there as something of a social constructionist. But that’s a mistake. The scientists are not constructing the world. They are constructing ways to describe the actual world with more and more precision.
I often hear that said by philosophers and by scientists. Yet it is clearly false.
Theories do not make predictions. Theories + data lead to predictions.
The data are the representations. We use mathematics applied to the data and to the constraints of the representation system, in order to predict future data. That future data is itself a representation (a predicted representation). We then use the theory as protocols that connect the representations to reality, so that we can interpret that predicted data in the form of predicted real world events.
If the theory fits well, then this process works well. So it is a good measure of how well our representation system fits the world that it is expected to represent.
Constructing useful representation systems — that’s the kind of thing that comes from geometric thinking.
Yes. You understand me correctly on that.
But why should I believe that?
A realist reply could be that in fact one of the following one always obtain:
1. The theories are isomorphic. One example would be the discovered equivalence of that the competing wave equation and the matrix versions in early QM work. ETA: That’s not such a good example, since, as per Walt’s QM Interpretations thread, we still need to add an interpretation. But hopefully my basic point is clear.
2. When the communities compared theories, they agreed on evidence that one was superior. The competition between wave and particle theories of light, resolved by Fresnel experiments, would be an example.
3. A third theory superior both in ways that both communities agreed on would be discovered.
I think you need to look at the history of actual theories to help make the case for the above the realist position versus your assertion about what would happen in independent communities.
I agree that we construct theories. But I see the last sentence as just asserting the anti-realist position. The realist would reply that the arguments and proposed research program given in my previous note show that in fact our theories do eventually represent the world.
I don’t think that calling realism a religion is fair. First, I understand it has only become the majority position recently. Second, and more important, the realists position is based on argument, not faith. Last, there are many opposed to the position and it is not seen as a closed issue; they anti-realists have strong arguments which realists acknowledge.
I think you cannot just assert that the representations/structures of mature, successful theories are not part of a convergent series. You have to check and see. I agree paradigm shifts would need to be part of that analysis — whatever you claimed was converging would have to survive the paradigm shift. I believe the completion of such work is part of the realists position. Of course, whether the results support the realist position is an open issue. But the point is that philosophers are undertaking that type of analysis.
If I understand your concluding paragraphs on how science theories are constructed, I think I agree. The disagreement is regarding what the results of that entire scientific process, including that construction process, tell us about the world.
Great. I’m happy to quit while I am ahead.
I use that to illustrate why I doubt convergence of theories. I did not present it as an empirical claim.
Stop right there. I consider myself a realist. I resent your repeated attempts to depict me as anti-realist.
I’ve read some of van Fraassen on anti-realism, and I don’t agree with it.
As far as I know, the French language and the Chinese language are not even close to being isomorphic. Yet they both describe the same world, and they both do it well enough that neither language group is thinking of switching.
My last sentence above would seem to apply here.
No, it wouldn’t. Those were not alternative representation systems. Those were alternative hypotheses both presented within a common representation system.
I see that as, in effect, saying that anyone who believes that French and Chinese are distinct languages, is an anti-realist. It’s absurd.
Then it is just as well that I didn’t. You interpolated the word “realism”.
I don’t have a problem with realism. I have a problem with the unrealistic account of science that is given by philosophers of science.
I’ve been checking to the extent possible. I spent a lot of time reading history of science (probably the popularized version) in my teen years. My views on science partly reflect what I learned during those years.
If scientific theories arose by induction, as philosophy of science claims, then we might expect them to converge. But they do not arise by induction. They arise by clever construction. And the constructors are not obliged to make sure that what they construct will be part of a convergent sequence.
The traditional philosophy of science — the view that I criticize — says that we start with data, and form generalizations. By contrast, I say that science starts before there is data, and part of the theory is in defining the data.
In the physics of electricity and magnetism, the early scientists started before there was useful data. It was quite a struggle to come up with good ways of getting data. Our current laws are pretty much definitions of voltage, current, resistance, etc. They are prior to the data from which they are alleged to have been induced.
There was no possibility of getting data on gravitational forces between the planet and the sun before we had Newton’s law of gravity. We needed Newton’s law, together with a famous experiment by Cavendish, before we could even estimate the mass of the sun (or the masses of the planets).
I have always thought of science as imagination and invention followed by selection. Rinse, iterate.
Neil,
If you think that QM expressed in French has not converged with QM expressed in Chinese, then no wonder you’re having trouble finding common ground with Bruce.
If you think I was claiming that, then it is no wonder that we are miscommunicating.
I was talking about ordinary non-technical Chinese language and ordinary non-technical French language used to describe the ordinary commonsense world we see around us.
That seems reasonable.
Neil,
I’m going by what you wrote.
You said:
Bruce asked:
You responded:
And earlier:
For the record, do you think that QM as expressed in French has converged with QM as expressed in Chinese?
Neil: Thanks for this detailed reply, and I think I understand your position better.
I should have been clearer when referring to realism: I meant the philosophical position of scientific realism, which says that some aspect of the best scientific theories, such as the terms used in the theory or the structures in the theory, state something true about what exists in reality.. I had always understood you as saying that since humans invent the representations used in science, these representations could not be expected to conform to the entities in reality; instead of telling about the essence of reality, the main expectation of good science was that it would be useful for prediction. I’d call the latter position anti-realism.
But I seem to have hit a nerve with that characterization of your position so sorry for the misunderstanding.
I realized after the edit period had expired that you said it was philosophy that was the (secular) religion, adding that its expectation that science truly depicts reality is a dogma of that religion. I do have the same concerns with calling the position of scientific realism a dogma.
I see Keith has got back from vacation (a guess on my part!). I am happy to pass the torch to him. Thanks for the stimulating exchange.
Yes, I said that. But it clearly does not apply. The Chinese and French have not independently developed QM. Rather, they have all participated in global scientific research.
My view is that there infinitely many entities in reality — an uncountable infinitude of them. We pick out a small subset and give them names.
I don’t see any reason why the ones that we pick out and name should be any more real or any less real than the ones that go unnamed.
Overall, we might compare this to the Dawkins – Gould disagreement. Suppose that we could rewind the tape of the cosmos, and let it play out again. Dawkins says that we would finish up with about the same biosphere, because it is a convergent process. Gould says that what evolves depends on many contingencies, and we would likely end up with a vastly different biosphere.
I agree with Gould on that. And I have a similar view about which scientific theories would emerge.
I hope that gives a little more perspective.