>Is the thing you are defending verificationism, or anti-realism?
The former. My position isn’t so much anti-realism as it is that realism and anti-realism are both incoherent.
>..here you argue “from* verificationism:-
It’s a bit tricky to make a positive case for a negative claim. I’m denying that some class of statements is meaningful. I do that by trying to draw a coherent picture of how one can do all the things we want to do without referring to these purported meaningless statements, and by pointing out that nobody has yet given or pointed at a reasonable account of meaning for those statements. I cite EY’s account of meaning and show that it’s not required.
>Both sides of the many worlds debate appear to understand what “causally isolated worlds” means, the evidence for which is that they can actually communicate their disagreements about it.
The fact that people can debate a topic does not imply that topic is meaningful. EY gave an example of that re literary claims, I just think it applies far more broadly.
>If verificationism means that “exists” is a meaningless word, then “this territory does not exist” is a meaningless claim not a true claim.
Correct. I just thought it was a snappy title. My claim is really that “this territory exists/does not exist” is incoherent. Maybe that’s throwing people off?
>What? What’s a “map claim”?
We have a map that says “X”. If the map also says “X exists”, that’s not adding anything useful or meaningful to the map.
The fact that people can debate a topic does not imply that topic is meaningful
Yes it does, using the ordinary linguistic definition of meaning. There’s no way of making the point without begging the question.
EY presents an example,post collonial literature that is meaningless according to his intuition. You present an example , causally non-interacting worlds, that is meaningless according to your intuition, but which he accepts!
>Yes it does, using the ordinary linguistic definition of meaning. There’s no way of making the point without begging the question.
Well, if you explained to them what they were using language for, they would presumably disagree. Ask your friends whether, by talking about reality, they simply mean “an assumption that makes science simpler”, or any other of the accounts you and others have offered in the comments, and I suspect most will say no. There’s two possibilities: either their usage of reality/exist is meaningless, or they’re mistaken about what it means. For my purposes, accepting either of these is a significant step towards my view.
>You present an example , causally non-interacting worlds
Remember, I think realism as applied to the world that does causally interact with us is also incoherent. My first example was just to warm things up.
I don’t think people would agree with this as an account of what they mean by reality. Calling it an assumption already conflicts with what most people intuitively “believe”.
It’s not novel, the core idea is at least a century old.
You’re right, I haven’t proven it. I’ve challenged everyone to provide an alternative account of definition that makes it meaningful, and over a hundred comments later nobody has done so.
You’re right, I haven’t proven it. I’ve challenged everyone to provide an alternative account of definition that makes it meaningful, and over a hundred comments later nobody has done so.
The objections you keep making are that alternative suggestions are meaningless given your definition of meaningful. In other words, that they are wrong because you are right. That alternative accounts are wrong because they are different to the one true account.
To make progress you need a way of engaging that isn’t question-begging.
No, I’ve objected that the alternative definitions are circular, and assume the coherency as part of the definition. That is a valid critique even without assuming that it’s incoherent from the outset.
It’s a bit tricky to make a positive case for a negative claim
Verification is also a positive claim. It indicates that whenever a new instrument is invented , a dark matter detector or a ghost detector, a set of statement that were previously meaningless become meaningful. In a way that is completely unrelated to their apparent comprehensibility and usefulness in communication.
>It indicates that whenever a new instrument is invented , a dark matter detector or a ghost detector, a set of statement that were previously meaningless become meaningful.
Disagree—none of those are new ways of observation. We can only observe through the senses. All of those instruments only affect us through our senses, and don’t change the meaning of any statements.
Now, if we managed to get a sixth sense, perhaps I’d have to modify the theory, probably to talk about input into the brain instead of observations, since the brain is all we really have direct access to. And if you start messing with brain inputs, that’s enough of an edge case I don’t expect any theory to survive intact.
A statement is meaningful if it constrains expectations. If you say “we will be able to directly measure dark energy in the future”, that’s meaningful—I can imagine a set of sense data that would satisfy that (peer reviewed paper gets published, machine gets built, paper released claiming to have measured it, etc).
But whether a sentence constrains expectations depends on what instrumentation is possible. We don’t know that, which means we can’t say now that any given sentence is verificationally meaningful. Which means that verificationism is incoherent by your definition.
Disagree. Either a sentence makes predictions about observations or it doesn’t.
>Which means that verificationism is incoherent by your definition.
How so? As explained multiple times, verificationism is an account of meaning / definitional, which itself doesn’t need to be verifiable.
>we can’t say now that any given sentence is verificationally meaningful.
I don’t agree with this, but even if I concede this, it doesn’t imply that verificationism is incoherent. Nothing about my account of meaning implies that it should be tractable to tell whether sentences are meaningful in all cases. Regardless, can you give an example of a sentence that you think we can’t know if it’s meaningful on my definition? I suspect if phrased correctly it will either be clearly meaningful or clearly meaningless under my criteria, and any ambiguity will be based on phrasing. As above, “we will be able to detect dark energy one day” is coherent. “Dark energy is responsible for X observation” is coherent if understood as also incorporating the detection claim as well, but not otherwise. I assume you can see why “dark energy is responsible for X observation, but we’ll never be able to detect it any better than we do now” is partially meaningless? It’s equivalent to “dark energy is not responsible for X observation”. The claim “dark energy is responsible”, on its own, is not relevant to any predictions; the claim along with a claim about future detection abilities is.
Disagree. Either a sentence makes predictions about observations or it doesn’t
Very few sentences make explicit predictions. “Atoms exist” doesn’t. So you either have to include implicit predictions or have a very small set of meaningful sentences. But implications of predicability depend on other claims and facts, which arent necessarily available. So the ordinary theory of meaning is better at explaining how communication works than the verificationist one. In particular, scientists need to hold discussions about how to detect some hypothetical particle or force before a detector is built.
Regardless, can you give an example of a sentence that you think we can’t know if it’s meaningful on my definition
Pretty much anything that is subject to philosophical dispute. “God exists” because there are interactive and non interactive (deistic) definitions of God. Mind body dualism , because it also come in Interactive and non interactive versions. Most novel physics.
Nothing about my account of meaning implies that it should be tractable to tell whether sentences are meaningful in all cases.
That is an implication of how have you defined “coherence”.
>So the ordinary theory of meaning is better at explaining how communication works than the verificationist one.
Not sure what ordinary theory you’re referring to.
> In particular, scientists need to hold discussions about how to detect some hypothetical particle or force before a detector is built.
Perfectly consistent with my view. To spell it out in my terms: someone proposes a revision to the Standard Map which includes new entities. It’s initially unclear whether this revision produces different predictions (and therefore unclear if this revision is meaningful). Scientists discuss possible experiments that would come out differently based on this map, and if they figure one out, then they’ve determined that the revision is meaningful and can then test it.
I submit that the above *actually represents* how many physicists think about various formulations of QM that makes the same predictions, and how they treat new theories that initially don’t appear to make new predictions.
>”God exists” because there are interactive and non interactive (deistic) definitions of God. Mind body dualism , because it also come in Interactive and non interactive versions. Most novel physics.
“God exists” can be understood as making predictions or not depending on which variant. It’s alternatively meaningful or meaningless depending on which is meant. Honestly, I think many would agree that certain forms of that claim are meaningless, e.g. pantheism.
>That is an implication of how have you defined “coherence”.
It’s not undecidable. It can be understood in multiple ways, some of which are meaningful, and some not.
If I’m teaching a class, and at some point say “the proposition which I just wrote on the board is correct”, that statement will be meaningful or meaningless depending on what statement was written. Same for a proposition that refers to a “God” concept—if it’s referring to versions of that concept which are meaningful, then it’s meaningful.
But whether it’s referring to a version of the concept that is “meaningful isn’t clear.
You are now saying that every proposition is decideably meaningless/full , depending on some further facts about what it is “really” about...facts which may never become apparent.
>You are now saying that every proposition is decideably meaningless/full , depending on some further facts about what it is “really” about...facts which may never become apparent.
No, only incredibly vague statements like my example or like “God exists”.
So.. previously you were saying that there is one kind of meaninglessness , consisting of unverifiability. Now you are saying that there is another kind, consisting of vagueness .
No, a statement can be vague about whether it refers to meaningful statement A or meaningless statement B. That statement as a whole is unverifiable because it’s unclear which it refers to.
Scientists discuss possible experiments that would come out differently based on this map, and if they figure one out, then they’ve determined that the revision is meaningful and can then test it.
And if it turns out that the new particle or force is indetectable , their discussions were retrospectively meaningless, by your definition..despite the fact that they were communicating successfully. You need to show that the ordinary theory is false, and to show that verificationism is true.
Of course, that’s an appeal to the standard theory..and there is nothing wrong with that. You are making a novel, contentious claim about what “meaning” always meant. Verificationism less than a hundred years old. Modern linguistics is at least twice as old. We were never in a vacuum about what “meaning” means.
Your stipulative definition doesn’t match ordinary usage, so why should anyone accept it?
And if it turns out that the new particle or force is indetectable , their discussions were retrospectively meaningless, by your definition..despite the fact that they were communicating successfully.
No—those discussions were about a meaningful purely mathematical question—does X map differ from Y map in an observable manner?
Re standard model—as elsewhere, most people will agree with both of these statements:
There is some sense in which “external reality exists” is true
This is not related to ease of communication. External reality would exist even without any communication and if language had never been invented.
I don’t see how those can be squared away with an account of meaning solely grounded in communication, when the parties to that communication will strongly dispute that their meaning is grounded in communication.
I don’t see how those can be squared away with an account of meaning solely grounded in communication, when the parties to that communication will strongly dispute that their meaning is grounded in communication.
People can be wrong. You could be under the impression that you are speaking Mandarin when you are speaking English. The object level is not the meta level. If you can’t speak English , and I can’t speak mandarin, the fact that we are communicating means one of us is wrong.
What coordinated action is taken that can only be explained by assuming they’ve managed to communicate about something unverifiable in my sense (i.e. external reality)?
Recall that verificationism and anti realism are different things. I don’t have to prove realism in order to show that the verificationist criterion of meaning is not the only one.
Which definition have you put forward? My complaint is that the definitions are circular.
>The counter argument is that since realism is valuable, at least to some, verificationism is too limited as a theory of meaning .
I would deny that one can meaningfully have preferences over incoherent claims, and note that one can’t validly reason that something is coherent based on the fact that one can have a preference over it, as that would be question-begging.
That said, if you have a good argument for why realism can be valuable, it might be relevant. But all you actually have is an assertion that some find it valuable.
Meanwhile, you’ve asserted both that communication implies meaning, and that parties to a communication can be mistaken about what something means. I don’t see how the two are consistent.
I do that by trying to draw a coherent picture of how one can do all the things “we want to do* without referring to thm*ese purported meaningless statements,
There’s no uniform set of values that everyone has.
There are different ways of responding to the failure of strong scientific realism. One is to adopt instrumentalism , aiming only for predictive accuracy,and abandoning the search for ontological truth. It’s difficult to be a consistent instrumentalist, in something like the way it’s difficult to be a committed solipsist. People tend to get involved in science because they care about the nature of reality. If you care about the nature of reality, instrumentalism means giving up on some expected value
I’m not sure why I should care about something I consider to be incoherent.
If there’s something specific you think you’d like to do and can’t without realism, then can you name it? EY named altruism past the observable border, but as I pointed out any kind of altruism requires the same realism assumption, and altruism remains hard to ground even with that assumption, so it’s not particularly compelling as an argument for realism, let alone as an argument that realism is coherent.
I don’t have a preference for coherence. That’s not a value. It’s just part of the meaning of value, that it must be coherent.
I haven’t given a rigorous definition for coherence, but I’ve given some criteria—a coherent concept should be capable of explanation, and so far that’s not been met.
Definitions aren’t true or false, they can be representative of what people mean by certain words to a greater or lesser extent. If you poll people and ask if values can be incoherent and still valid I expect most to say no?
>Is the thing you are defending verificationism, or anti-realism?
The former. My position isn’t so much anti-realism as it is that realism and anti-realism are both incoherent.
>..here you argue “from* verificationism:-
It’s a bit tricky to make a positive case for a negative claim. I’m denying that some class of statements is meaningful. I do that by trying to draw a coherent picture of how one can do all the things we want to do without referring to these purported meaningless statements, and by pointing out that nobody has yet given or pointed at a reasonable account of meaning for those statements. I cite EY’s account of meaning and show that it’s not required.
>Both sides of the many worlds debate appear to understand what “causally isolated worlds” means, the evidence for which is that they can actually communicate their disagreements about it.
The fact that people can debate a topic does not imply that topic is meaningful. EY gave an example of that re literary claims, I just think it applies far more broadly.
>If verificationism means that “exists” is a meaningless word, then “this territory does not exist” is a meaningless claim not a true claim.
Correct. I just thought it was a snappy title. My claim is really that “this territory exists/does not exist” is incoherent. Maybe that’s throwing people off?
>What? What’s a “map claim”?
We have a map that says “X”. If the map also says “X exists”, that’s not adding anything useful or meaningful to the map.
Yes it does, using the ordinary linguistic definition of meaning. There’s no way of making the point without begging the question.
EY presents an example,post collonial literature that is meaningless according to his intuition. You present an example , causally non-interacting worlds, that is meaningless according to your intuition, but which he accepts!
>Yes it does, using the ordinary linguistic definition of meaning. There’s no way of making the point without begging the question.
Well, if you explained to them what they were using language for, they would presumably disagree. Ask your friends whether, by talking about reality, they simply mean “an assumption that makes science simpler”, or any other of the accounts you and others have offered in the comments, and I suspect most will say no. There’s two possibilities: either their usage of reality/exist is meaningless, or they’re mistaken about what it means. For my purposes, accepting either of these is a significant step towards my view.
>You present an example , causally non-interacting worlds
Remember, I think realism as applied to the world that does causally interact with us is also incoherent. My first example was just to warm things up.
Reality is an assumption that makes science comprehensible.
I don’t think people would agree with this as an account of what they mean by reality. Calling it an assumption already conflicts with what most people intuitively “believe”.
I thought your claim was that “reality” has no meaning.
It is. That doesn’t conflict with what I said?
How can people have beliefs about reality if it has no meaning ?
Their beliefs are meaningless. The fact that they think their beliefs are meaningful doesn’t change that. People can be wrong.
You haven’t proven that , because you haven’t proven that your novel theory of meaning is the only correct one.
It’s not novel, the core idea is at least a century old.
You’re right, I haven’t proven it. I’ve challenged everyone to provide an alternative account of definition that makes it meaningful, and over a hundred comments later nobody has done so.
Which is very young compared to the total history of philosophy and fairly young compared to modern linguistics.
The objections you keep making are that alternative suggestions are meaningless given your definition of meaningful. In other words, that they are wrong because you are right. That alternative accounts are wrong because they are different to the one true account.
To make progress you need a way of engaging that isn’t question-begging.
No, I’ve objected that the alternative definitions are circular, and assume the coherency as part of the definition. That is a valid critique even without assuming that it’s incoherent from the outset.
Verification is also a positive claim. It indicates that whenever a new instrument is invented , a dark matter detector or a ghost detector, a set of statement that were previously meaningless become meaningful. In a way that is completely unrelated to their apparent comprehensibility and usefulness in communication.
>It indicates that whenever a new instrument is invented , a dark matter detector or a ghost detector, a set of statement that were previously meaningless become meaningful.
Disagree—none of those are new ways of observation. We can only observe through the senses. All of those instruments only affect us through our senses, and don’t change the meaning of any statements.
Now, if we managed to get a sixth sense, perhaps I’d have to modify the theory, probably to talk about input into the brain instead of observations, since the brain is all we really have direct access to. And if you start messing with brain inputs, that’s enough of an edge case I don’t expect any theory to survive intact.
So a statement is meaningful if it could be supported by sensory evidence enhanced by any kind of instrument invented in the future?
A statement is meaningful if it constrains expectations. If you say “we will be able to directly measure dark energy in the future”, that’s meaningful—I can imagine a set of sense data that would satisfy that (peer reviewed paper gets published, machine gets built, paper released claiming to have measured it, etc).
But whether a sentence constrains expectations depends on what instrumentation is possible. We don’t know that, which means we can’t say now that any given sentence is verificationally meaningful. Which means that verificationism is incoherent by your definition.
Disagree. Either a sentence makes predictions about observations or it doesn’t.
>Which means that verificationism is incoherent by your definition.
How so? As explained multiple times, verificationism is an account of meaning / definitional, which itself doesn’t need to be verifiable.
>we can’t say now that any given sentence is verificationally meaningful.
I don’t agree with this, but even if I concede this, it doesn’t imply that verificationism is incoherent. Nothing about my account of meaning implies that it should be tractable to tell whether sentences are meaningful in all cases. Regardless, can you give an example of a sentence that you think we can’t know if it’s meaningful on my definition? I suspect if phrased correctly it will either be clearly meaningful or clearly meaningless under my criteria, and any ambiguity will be based on phrasing. As above, “we will be able to detect dark energy one day” is coherent. “Dark energy is responsible for X observation” is coherent if understood as also incorporating the detection claim as well, but not otherwise. I assume you can see why “dark energy is responsible for X observation, but we’ll never be able to detect it any better than we do now” is partially meaningless? It’s equivalent to “dark energy is not responsible for X observation”. The claim “dark energy is responsible”, on its own, is not relevant to any predictions; the claim along with a claim about future detection abilities is.
Very few sentences make explicit predictions. “Atoms exist” doesn’t. So you either have to include implicit predictions or have a very small set of meaningful sentences. But implications of predicability depend on other claims and facts, which arent necessarily available. So the ordinary theory of meaning is better at explaining how communication works than the verificationist one. In particular, scientists need to hold discussions about how to detect some hypothetical particle or force before a detector is built.
Pretty much anything that is subject to philosophical dispute. “God exists” because there are interactive and non interactive (deistic) definitions of God. Mind body dualism , because it also come in Interactive and non interactive versions. Most novel physics.
That is an implication of how have you defined “coherence”.
>So the ordinary theory of meaning is better at explaining how communication works than the verificationist one.
Not sure what ordinary theory you’re referring to.
> In particular, scientists need to hold discussions about how to detect some hypothetical particle or force before a detector is built.
Perfectly consistent with my view. To spell it out in my terms: someone proposes a revision to the Standard Map which includes new entities. It’s initially unclear whether this revision produces different predictions (and therefore unclear if this revision is meaningful). Scientists discuss possible experiments that would come out differently based on this map, and if they figure one out, then they’ve determined that the revision is meaningful and can then test it.
I submit that the above *actually represents* how many physicists think about various formulations of QM that makes the same predictions, and how they treat new theories that initially don’t appear to make new predictions.
>”God exists” because there are interactive and non interactive (deistic) definitions of God. Mind body dualism , because it also come in Interactive and non interactive versions. Most novel physics.
“God exists” can be understood as making predictions or not depending on which variant. It’s alternatively meaningful or meaningless depending on which is meant. Honestly, I think many would agree that certain forms of that claim are meaningless, e.g. pantheism.
>That is an implication of how have you defined “coherence”.
Elaborate?
So it’s a robust example of a proposition whose meaningfulness is undecidable, as required.
Which is to say that the proposition per se is undecidable.
It’s not undecidable. It can be understood in multiple ways, some of which are meaningful, and some not.
If I’m teaching a class, and at some point say “the proposition which I just wrote on the board is correct”, that statement will be meaningful or meaningless depending on what statement was written. Same for a proposition that refers to a “God” concept—if it’s referring to versions of that concept which are meaningful, then it’s meaningful.
But whether it’s referring to a version of the concept that is “meaningful isn’t clear.
You are now saying that every proposition is decideably meaningless/full , depending on some further facts about what it is “really” about...facts which may never become apparent.
>You are now saying that every proposition is decideably meaningless/full , depending on some further facts about what it is “really” about...facts which may never become apparent.
No, only incredibly vague statements like my example or like “God exists”.
So.. previously you were saying that there is one kind of meaninglessness , consisting of unverifiability. Now you are saying that there is another kind, consisting of vagueness .
No, a statement can be vague about whether it refers to meaningful statement A or meaningless statement B. That statement as a whole is unverifiable because it’s unclear which it refers to.
Presence of shared meaning enabled communication.
Absence of share meaning prevents communication.
Basically, meaning is about communication.
And if it turns out that the new particle or force is indetectable , their discussions were retrospectively meaningless, by your definition..despite the fact that they were communicating successfully. You need to show that the ordinary theory is false, and to show that verificationism is true.
Of course, that’s an appeal to the standard theory..and there is nothing wrong with that. You are making a novel, contentious claim about what “meaning” always meant. Verificationism less than a hundred years old. Modern linguistics is at least twice as old. We were never in a vacuum about what “meaning” means.
Your stipulative definition doesn’t match ordinary usage, so why should anyone accept it?
No—those discussions were about a meaningful purely mathematical question—does X map differ from Y map in an observable manner?
Re standard model—as elsewhere, most people will agree with both of these statements:
There is some sense in which “external reality exists” is true
This is not related to ease of communication. External reality would exist even without any communication and if language had never been invented.
I don’t see how those can be squared away with an account of meaning solely grounded in communication, when the parties to that communication will strongly dispute that their meaning is grounded in communication.
People can be wrong. You could be under the impression that you are speaking Mandarin when you are speaking English. The object level is not the meta level. If you can’t speak English , and I can’t speak mandarin, the fact that we are communicating means one of us is wrong.
If they can be wrong about that, why can’t they be wrong about whether what they’re saying is meaningful?
Because there is evidence of successful communication in coordinated action.
What coordinated action is taken that can only be explained by assuming they’ve managed to communicate about something unverifiable in my sense (i.e. external reality)?
I don’t have to assume your sense is correct .
That’s not responsive to my question. I didn’t say you needed to assume that.
Recall that verificationism and anti realism are different things. I don’t have to prove realism in order to show that the verificationist criterion of meaning is not the only one.
Sure, I don’t think anything I’ve said is inconsistent with that?
Whenever I try to put forward a defense of realism , you say it is in meaningless under the verificationist definition of meaning.
But everyone knows that realism is hard to justify using verificationism.
The counter argument is that since realism is valuable, at least to some, verificationism is too limited as a theory of meaning .
So there is a ponens/ tolens thing going on.
Which definition have you put forward? My complaint is that the definitions are circular.
>The counter argument is that since realism is valuable, at least to some, verificationism is too limited as a theory of meaning .
I would deny that one can meaningfully have preferences over incoherent claims, and note that one can’t validly reason that something is coherent based on the fact that one can have a preference over it, as that would be question-begging.
That said, if you have a good argument for why realism can be valuable, it might be relevant. But all you actually have is an assertion that some find it valuable.
Meanwhile, you’ve asserted both that communication implies meaning, and that parties to a communication can be mistaken about what something means. I don’t see how the two are consistent.
Meaningless! Incoherent!
Incoherent! Meaningless!
Those words are interchangable. Not sure what your point is.
There’s no uniform set of values that everyone has.
There are different ways of responding to the failure of strong scientific realism. One is to adopt instrumentalism , aiming only for predictive accuracy,and abandoning the search for ontological truth. It’s difficult to be a consistent instrumentalist, in something like the way it’s difficult to be a committed solipsist. People tend to get involved in science because they care about the nature of reality. If you care about the nature of reality, instrumentalism means giving up on some expected value
I’m not sure why I should care about something I consider to be incoherent.
If there’s something specific you think you’d like to do and can’t without realism, then can you name it? EY named altruism past the observable border, but as I pointed out any kind of altruism requires the same realism assumption, and altruism remains hard to ground even with that assumption, so it’s not particularly compelling as an argument for realism, let alone as an argument that realism is coherent.
I am not dictating to you what your values should be. I am just pointing out that you don’t get to dictate to others what their values should be.
It’s hard to even define “do” without realism. You need a real mount Everest to climb mount Everest.
And haven’t you said that you are not an anti-realist?
> I am just pointing out that you don’t get to dictate to others what their values should be.
For coherent values, sure. But a preference for something incoherent to be correct doesn’t seem like a real value to me.
>You need a real mount Everest to climb mount Everest.
But not to have the experience of climbing mount Everest.
>And haven’t you said that you are not an anti-realist?
Yes, realism is incoherent. If you disagree, at least some of the burden should fall on you to define it or explain why it’s a useful concept.
You haven’t defined incoherence, and you are also treating the preference for coherence like an objective value anyone must have.
I don’t have a preference for coherence. That’s not a value. It’s just part of the meaning of value, that it must be coherent.
I haven’t given a rigorous definition for coherence, but I’ve given some criteria—a coherent concept should be capable of explanation, and so far that’s not been met.
Is there some experiment or observation that proves that statement to be true?
Definitions aren’t true or false, they can be representative of what people mean by certain words to a greater or lesser extent. If you poll people and ask if values can be incoherent and still valid I expect most to say no?
So you are almost but not quite saying that there is a separate category of analytical truths.
But saying “this is a map of Narnia, which does not exist” ,says something useful.. something which stops you sailing off to find Narnia.
“this is a map of Narnia which should not be used to predict experiences”
Really, using the Solomonoff induction model, you’d just put a very low probability weight on that map since Narnia is complicated to define.
I think you are right that Solomonoff can’t be simultaneously expected to give you both efficient predictions and correspondence to objective reality.