A problem here, I believe, is that you are assuming that there must be some kind of correspondence of our mental constructs of the world and the world in itself. The structure of the model must somehow reflect the structure of the world. But how can we verify this assumption? — boundless

I think Wittgenstein’s Tractatus may offer a solution here. That is in order for us to make sense of the world, that is to avoid speaking non sense, our language, mental construct, and the world must be isomorphic. This is not an outcome of empirical verification but of logical analysis.

Maybe individuating the JWST as 'a thing' is a mental imputation. — boundless

No argument here since I did a whole topic on that (2 topics ago). But similarly, you, as 'a thing' is also just a mental imputation.

Note that my point is that physical quantities are defined in a relational way from the start.

Again agree. While there are some objective constants, physical quantities and units don't seem to be among them.

Let's consider the Wigner's friend scenario, where the Friend makes an experiment in a lab which is locked from the outside. — boundless

Lock is unimportant. The hypothetical lab needs to be a box from which zero information can escape. We presume this, but in reality, such box would kill its occupants.

The friend, as described here, seems to serve no purpose since he simply reports what the device does, and the device alone would have sufficed. The friend perhaps only serves a significant role in the 'consciousness causes collapse' interpretations.

So Wigner observes a superposition state until the box is opened, at which point the wave function (relative to Wigner) collapses. Pretty straight forward.

Wigner is not 'entilted' to go outside of it and ask himself what the Friend, in the Friend's perspective is seeing.

You can always put another observer outside, perhaps outside a box containing Wigner and the inner box. What is demonstrated by doing this?

Assuming that the Friend also has his 'perspective'

As does the device measuring the (say) spin of some particle. The wave function collapses for both almost immediately upon this measurement. Wigner has to wait for his wave function (of the box) to collapse.

Still both of them do not actually know what the other truly observed.

Wigner knows when the box is opened. The friend might know everything right away. The box cannot let information out, but letting information in is allowed.

Only that, in their own perspective, there are no logical inconsistencies. For Wigner it is as if the Friend sees the same as he sees. But it cannot say what is truly seen by the Friend.

I don't know what you mean by 'truly' here. This is a relational view. There is no objective truth going on anywhere. Nobody notices anything weird.

This also means that under RQM (and, really, QBism and similar) Wigner can't even say that there are 'perspectives' other than his own with certainty.

The friend who notices spin up has a perspective, as does the friend noticing spin down. Those are two perspectives in superposition (relative to Wigner). Wigner knows this. What he doesn't know is which state things will collapse to relative to him when the box is opened. That part is a counterfactual.

Only positing something beyond the 'perspectives' can ground intersubjective agreement.

Where do you get this? Wigner subjectively sees up once box is opened. Friend sees up earlier than that, but it isn't intersubjective until they compare findings, so none of it is beyond anybody's perspectives. The agreement is grounded in empirical perspectives.

This implies that one cannot know what is 'beyond' one's perspective.

That I will agree with. It is an epistemological statement, not worded in an ontic manner. RQM is not about epistemology.

As I see it, there is nothing in RQM (and, really, also in QBism and similar) that 'Mars in the perspective of Y' and 'Mars in the perspective of Z' are the same thing. Y will never find inconsistencies.

Agree with the last statement, but not that the two perspectives (at different times, same place) are the same thing. Lots of changes can occur during those 20 minutes, lots of wave function collapses.

The problem with this IMO it is that we are 'anthropomorphizing' the pen.

I'm not. The pen has no awareness of that which it measures. The interaction definition has nothing to do with consciousness or people at all.

... But how the world appears to a pen

The world does not 'appear' at all to the pen. It just exists in some state relative to the pen. That's what I mean by a perspective. It's just a system state at a moment in time, a system capable of being affected by past events, so a vacuum state won't do.

Regarding MWI, ... I am not sure if the 'preferred basis problem' (i.e. how to explain in MWI that the wavefunction can be decomposed in a way to explain the appearance of the 'classical world') has been solved and, also, it's not clear to me how the Born Rule is explained in this interpretation. — boundless

Those are straight out of wiki. The former has arguably been solved. The latter as well, but arguably less so. Copenhagen doesn't derive it: It is just postulated up front. MWI could have done that.
Objective collapse interpretations also seem to do this. I can't think of one that derives it.
Apparently any counterfactual definition like Bohmian just postulates an initial state compatible with the Born rule, and from there it has foundational principles that preserve this distribution property.

But, yes, in a way the first 'objection' is not perhaps 'scientific' but simply philosophical.

That's a valid reason to prefer some other interpretation, but not a valid critique of it. The critique I quoted just above are valid critiques, and are or are not solved, depending who you ask.

Oddly enough, it is actually the closest physical theory to a 'ontological monism' that has been proposed (the universal wavefunction being only 'real thing' ...

Funny, but that's the part that makes me prefer another interpretation, not the stuff you listed above. See my response to Apu below.

If the division into physical objects is conceptual and doesn't reflect faithfully the structure of mind-independent world, how can we claim that we do have knowledge of the 'world beyond' our perspective? — boundless

We always build internal models, and while my model in some ways has correspondence to states in my world, I don't call my model 'knowledge' like it is some kind of accurate representation.
There is matter near me in my world and I cordon off a subset of that matter and designate it 'chair' despite the fact nothing in the physical world is a function of that subset.
Look at a person, which changes its component parts every second. Nevertheless, I designate a boundary to what I consider to be that person

Everything (not just humans) does this. It has pragmatic utility. This twig for my nest. My offspring as opposed to that of another. A molecule is about as close of a physical thing to an 'object' as I can think of. It has defined boundaries (most of the time) and has emergent properties that are not properties of the primitives which compose it.

But this still is based on some assumptions you make about the 'world in itself'. Assumptions that do not seem to be justified in light of scientific knowledge only.

Indeed. Even science makes such designations, again, finding it useful to do so.

How can you check that the description of the 'mind-independent world' actually matches its structure?

There's no exact match, and there's no check if by insane chance you got one actually right. The purpose of the model is not to be accurate. The purpose is to be useful, and to be useful, it merely needs to be accurate enough to predict what will actually be observed.

It seems a reasonable inference, yes, but can we have compelling reasons to assert that there is this correspondence?

The intersubjective agreement seems compelling enough.

from my subjectove perspective the issue is borderline close to "why is there anything at all?". — Apustimelogist

And lack of a rational answer to that question makes me ask a different question instead.

And lack of a rational answer to that question makes me ask a different question instead. — noAxioms

But again, why assume that such a vague, abstract, distal question can be given a coherent answer? Doesn't make sense to me, and you're never going to be able to replace it with a surrogate question which is simultaneously near equivalent but less vague and detached from the current capabilities of our knowledge.

Well, my reply would be that if this were not the case, then it would suggest a picture of the world and metaphysics which is much more inflated than I currently believe, where there is some kind of conspiratorial aspect of nature that deceives our senses. Even though this could be the case, I don't see any positive evidence to believe this over a simpler story of how the world works and how we relate to it like the one that has been built up through physics, biochemistry, neuroscience, etc. — Apustimelogist

Actually the conspirational nature is not to be invoked here. One might still assume that our cognitive functions are useful, i.e. have a pragmatic goal. Practical usefulness does not lead to accuracy.
The problem I see here is that one can't claim knowledge about the 'mind-independent world' if one doesn't make some assumptions that can't be proven empirically.

I don't think that anyone believes that newtonian mechanics gives us a literal picture of the world nowadays. Still, it is still immensely useful and in a sense a source of valid knowledge, if knowledge is interpreted in a pragmatic way.

I think Wittgenstein’s Tractatus may offer a solution here. That is in order for us to make sense of the world, that is to avoid speaking non sense, our language, mental construct, and the world must be isomorphic. This is not an outcome of empirical verification but of logic analysis. — Richard B

Ironically, Wittgenstein's Tractatus can also be invoked to support the view that one can't go outside one's perspective (see TLP 5.6-5.641...here a link). And in fact, one can cite the later Wittgenstein's view that sense can be pragmatic in nature. Even if my picture is wrong, then, if it still has pragmatic use, I don't see why it would be 'nonsense'.

One might still assume that our cognitive functions are useful, i.e. have a pragmatic goal. — boundless

You think it can be useful without having any correspondence to reality at all? Note that correspondence isn't like direct realism (naive realism?). You can say "my experience corresponds to things in reality" without saying "I'm experiencing reality raw, as it truly is, without any intermediary processing".

For example the experience of hearing music. The emotions I feel in response aren't out there in reality, but when I hear sounds they correspond to real frequencies and amplitudes in differential air pressure. You're suggesting that not even that kind of correspondence exists?

No argument here since I did a whole topic on that (2 topics ago). But similarly, you, as 'a thing' is also just a mental imputation. — noAxioms

I disagree, from my immediate experience I recognize that I have a private experience. Having a private experience strongly suggests to me that I am differentiated from the environment enough to be considered a distinct entity. I still do not see convincing arguments that refute this immediate phenomenological intuition.

Again agree. While there are some objective constants, physical quantities and units don't seem to be among them. — noAxioms

Note that constants are objective because their values are valid in all perspectives. They are not 'beyond' them.

Lock is unimportant. The hypothetical lab needs to be a box from which zero information can escape. We presume this, but in reality, and such box would kill its occupants. — noAxioms

Ok, point taken.

The friend, as described here, seems to serve no purpose since he simply reports what the device does, and the device alone would have sufficed. The friend perhaps only serves a significant role in the 'consciousness causes collapse' interpretations. — noAxioms

'Consciousness causes collapse' is to be interpreted as a phrase though. If collapse is merely an epistemic oupdate of a conscious agent, I don't see anything controversial. Of course, if consciousness causes a physical change, then things are different. So, let's not confuse these two distinct interpretations.

You can always put another observer outside, perhaps outside a box containing Wigner and the inner box. What is demonstrated by doing this? — noAxioms

That according to the external observer, let's call her Alice there is a superposition of Wigner, the Friend, the experimental device and the physical system. Not sure why you made this point however.

I don't know what you mean by 'truly' here. This is a relational view. There is no objective truth going on anywhere. Nobody notices anything weird. — noAxioms

I think that this view is problematic, however. For instance, the relational view expressed here still has to make the assumption that the 'perspective-bearers' have their existence independent from the perspectives. Also, it makes the assumption that its truth is perspective-independent. If my knowledge is restricted to what I can know from my own perspective, how can I know that?

The friend who notices spin up has a perspective, as does the friend noticing spin down. Those are two perspectives in superposition (relative to Wigner). Wigner knows this. What he doesn't know is which state things will collapse to relative to him when the box is opened. That part is a counterfactual. — noAxioms

Ok. But what about the ontological status of the two Friends? Also, he can't go outside his perspective, so what he can know is that he will never find inconsistencies. He can't in any way know that the Friend has his own perspective.

That I will agree with. It is an epistemological statement, not worded in an ontic manner. RQM is not about epistemology. — noAxioms

I agree with the first part. I do believe that RQM leads implicitly to an epistemology that is in tension with its ontology (I am not sure it is a contradiction, but still I am not sure it isn't for the reasons stated above).

I'm not. The pen has no awareness of that which it measures. The interaction definition has nothing to do with consciousness or people at all. — noAxioms

But you are still treating the pen as a 'perspective-bearer', i.e. something differentiated and something relative to which one can define a state of 'everything else'. And the state of 'everything else' is described via concepts that have practical usefulness in our perspective. Both these assumptions are not 'obvious'. Futhermore, if one adopts a relational standpoint, one can't never know that they are valid.

Those are straight out of wiki. The former has arguably been solved. The latter as well, but arguably less so. Copenhagen doesn't derive it: It is just postulated up front. MWI could have done that.
Objective collapse interpretations also seem to do this. I can't think of one that derives it.
Apparently any counterfactual definition like Bohmian just postulates an initial state compatible with the Born rule, and from there it has foundational principles that preserve this distribution property. — noAxioms

Ok, good point. But I am not sure that the 'preferred basis' is truly solved in a non 'for all practical purposes' way. Just like decoherence IMO isn't enough to explain collapse. But anyway the problem is tangential.

That's a valid reason to prefer some other interpretation, but not a valid critique of it. The critique I quoted just above are valid critiques, and are or are not solved, depending who you ask. — noAxioms

Ok! I can agree with that!

We always build internal models, and while my model in some ways has correspondence to states in my world, I don't call my model 'knowledge' like it is some kind of accurate representation.
There is matter near me in my world and I cordon off a subset of that matter and designate it 'chair' despite the fact nothing in the physical world is a function of that subset.
Look at a person, which changes its component parts every second. Nevertheless, I designate a boundary to what I consider to be that person — noAxioms

A person is differentiated in a way that a chair isn't. I, as a conscious human being, have a private conscious experience that strongly suggests to me that I am differentiated enought to be a distinct entity. I would say that other humans are like me in this respect. This is also probably true for animals, assuming that they are conscious beings.

A chair, however, doesn't seem to have a degree of differentiation to be considered a distinct entity.

Everything (not just humans) does this. It has pragmatic utility. — noAxioms

I am not sure everything builds internal models.

There's no exact match, and there's no check if by insane chance you got one actually right. The purpose of the model is not to be accurate. The purpose is to be useful, and to be useful, it merely needs to be accurate enough to predict what will actually be observed. — noAxioms

Agreed.

The intersubjective agreement seems compelling enough. — noAxioms

Bernard D'Espagnat distinguished two senses of objective. 'Strongly objective' is something that is independent from any cognitive perspective (a property of the 'world in itself'). 'Weakly objective' is something that every cognitive agent can agree upon. Nothing weakly objective can be assumed to be strongly objective.

I do believe however that intersubjective agreement leads to the assumption that, indeed, there is a world-in-itself.

You think it can be useful without having any correspondence to reality at all? Note that correspondence isn't like direct realism. You can say "my experience corresponds to things in reality" without saying "I'm experiencing reality raw, as it truly is, without any intermediary processing". — flannel jesus

Probably there is correspondence, but I don't think that we can know how the correspondence is. So, if the indirect realism you are positing is true (which I have no problem with), I am still in no position to know how the world appears to me relates with how the world is in itself.

If we can't go outside our perspective, we can't know how the world seen in my perspective relates to how the world is independent from it.

Yet, I also believe that there are good grounds to posit an independent reality as I explained in my posts. What I am questioning is how we can make claims of knowledge about it.

What I am questioning is how we can make claims of knowledge about it. — boundless

We can only do our best to figure out the stuff we have access to. If that's not knowledge then nothing is.

I think, yes, of course we could in the end be brains in vats, but I don't think that level of Skepticism is worth thinking about much (at best it's worth occasionally acknowledging), and then we just move on with the human endeavour of trying to figure out what we can about our world.

Part of what I sense is that there's a reluctance to allow for "knowledge" of non-fundamental things. Can I have knowledge that water is made of H2O even though I know that neither water nor H2O are fundamental? I think I can.

You don't really need to think about the brain in a vat scenario. You just need to concede the possibility that the 'independent reality' might not be be describable by using our conceptual frameworks, mathematical structure and so on. The structure of our mental models might not 'mirror' that of reality, even in principle.

On the other hand, yes, I can agree with you that pragmatic knowledge is knowledge. But it's not a knowledge that most realists would consider as 'true knowledge of the world'.

if that's not true knowledge, then nothing is

If we want to emerge from the subjective at all, from the realm of ideas, we must conceive of knowledge as an activity that does not create what is known but grasps what is already there.
— Basic Laws of Arithmetic, 23 — J

An idea qua idea is made in the mind and exists as an idea based on the existence of the mind in which it exists. There is the ontology of ideas.

But what is an idea, but an idea of something. Like a word, an idea, sitting in the mind, is about something "already there" before the idea of it was formed.

So we have to juggle both the subjective ontology of idea formation, and the objective metaphysics of what is thereby formed.

We set our ideas free and independent by holding them in our minds.

This is demonstrated when two people see the same idea. When one person conceives of the idea of mathematical addition and testifies to such subjective experience by asserting "2+2=4" and then a second person says, "Yes, like 3+17=20", the subjective ontology of addition as it is formed and exists in each subject, is simultaneously objective (independent and "already there"), as they both agree the idea of addition also must exist in each other's minds; it's the same addition each sees separately, in each other's minds, in 2+2 and in 3+17. This is both mind-independent (shared between two different subjects), and only there because of the minds that know addition.

Actually the conspirational nature is not to be invoked here. One might still assume that our cognitive functions are useful, i.e. have a pragmatic goal. Practical usefulness does not lead to accuracy.
The problem I see here is that one can't claim knowledge about the 'mind-independent world' if one doesn't make some assumptions that can't be proven empirically.

I don't think that anyone believes that newtonian mechanics gives us a literal picture of the world nowadays. Still, it is still immensely useful and in a sense a source of valid knowledge, if knowledge is interpreted in a pragmatic way. — boundless

I think the disagreement is that what you are attacking is some kind of unique objective description of the universe (e.g. Newtonian mechanics, falsely speaking). However, from the beginning of the conversation, I have just been talking about information about the world we gain from perception or observation. And we may put boundaries around objects in perception in different ways if we really want to; but, nonetheless, what appears on our retinas and other sensory boundaries are patterns that map to events or structures out in the world, mostly in a consistent manner. And this kind of consistent mapping (at least in some restricted relevant context) I think is actually the minimal requirement for pragmatism and use.

I do not support "mind-independent reality?" But I must say I do not understand anything you said.

All of reality is a reaction to what is. All things are a matter of cause and effect.

What the heck is a mind-independent reality other than a lack of awareness of the interactions of all things?

So we have to juggle both the subjective ontology of idea formation, and the objective metaphysics of what is thereby formed. — Fire Ologist

Yes, that was the distinction Frege drew between psychologism and logic.

as they both agree the idea of addition also must exist in each other's minds; it's the same addition each sees separately, in each other's minds, in 2+2 and in 3+17. This is both mind-independent (shared between two different subjects), and only there because of the minds that know addition. — Fire Ologist

OK, but mind-independent only in the sense of "not confined to my mind." It doesn't tell us whether these intersubjective sharings are mind-independent in the sense of "about something that exists regardless of whether either of us has the idea of it."

... when I hear sounds they correspond to real frequencies and amplitudes in differential air pressure. You're suggesting that not even that kind of correspondence exists? — flannel jesus

As an entanglement relation, I would suggest it exists. Almost all our pragmatic models involve such a relation, even if the relation isn't recognized as such.

Consciousness causes collapse' is to be interpreted as a phrase though. If collapse is merely an epistemic oupdate of a conscious agent, I don't see anything controversial. Of course, if consciousness causes a physical change, then things are different. So, let's not confuse these two distinct interpretations. — boundless

Agree that your discussion about Wigner's friend was framed in epistemic term. So the friend sort of fills a role in that respect, even if a simple printer would have also served.

Only that, in their own perspective, there are no logical inconsistencies. For Wigner it is as if the Friend sees the same as he sees. But it cannot say what is truly seen by the Friend.

I don't know what you mean by 'truly' here.. — noAxioms

OK, I think I worked it out. You're talking about Wigner's opinion of what the friend has measured while the friend is still in the box. That's a clear counterfactual, and unless an interpretation is used that posits counterfactuals, there is no 'truly' about it. RQM does not posit counterfactuals.

For instance, the relational view expressed here still has to make the assumption that the 'perspective-bearers' have their existence independent from the perspectives. — boundless

No, not at all. Existence of anything is relative to that which has measured the thing, and so far, our 'perspective bearers' have not been measured. They will momentarily, but then they're not the perspective bearers anymore, they're the observed.

Also, it makes the assumption that its truth is perspective-independent.

Quite the opposite. Where are you getting all this?

If my knowledge is restricted to what I can know from my own perspective, how can I know that?

That seems tautological. Perhaps I'm missing the question.

The friend who notices spin up has a perspective, as does the friend noticing spin down. Those are two perspectives in superposition (relative to Wigner). Wigner knows this. What he doesn't know is which state things will collapse to relative to him when the box is opened. That part is a counterfactual. — noAxioms
Ok. But what about the ontological status of the two Friends?

According to RQM, their ontology relative to Wigner is a superposition of states. According to other interpretations, the ontology is different. Ontology seems to be a mental construct, a function of say one's choice of interpretation, but it also might be a physical mind-independent status, depending on which (if any) interpretation is actually the case.
That statement is on-topic, it being kind of why I brought this up. I do agree that the title didn't convey it well, but I couldn't think of a title that did a better job.

Also, he can't go outside his perspective, so what he can know is that he will never find inconsistencies. He can't in any way know that the Friend has his own perspective.

Are you suggesting that Wigner isn't sure that the friend is like himself? That Wigner cannot discard solipsism? I suppose that's correct, but it's not considered a valid quantum interpretation since it leads to zero knowledge of anything. Ditto with superdeterminism, a loophole in Bell's proof, but you still don't see it included in the interpretations list.

But you are still treating the pen as a 'perspective-bearer', i.e. something differentiated and something relative to which one can define a state of 'everything else'. — boundless

Yes. I am not using any of those words as something requiring a human or other 'observer' to be involved.

Futhermore, if one adopts a relational standpoint, one can't never know that they are valid.

Logical analysis is enough to know they're valid. You can't know that they're sound of course.

Concerning MWI:

But I am not sure that the 'preferred basis' is truly solved in a non 'for all practical purposes' way. — boundless

I don't understand that problem enough to have an opinion about how problematic it is or to critique any solution proposed or counter-critique.
I said I don't buy it for different reasons than it offending my delicate sensibilities (the argument put forth in the Bell paper linked by the most recent post by @Wayfarer.

A person is differentiated in a way that a chair isn't. I, as a conscious human being, have a private conscious experience that strongly suggests to me that I am differentiated enough to be a distinct entity. I would say that other humans are like me in this respect. This is also probably true for animals, assuming that they are conscious beings.
It suggests to you, yes. Physics seems mute about it, which is my take.
Again, read the topic linked, which gets into exactly where a human boundary is.
Any biological cell is more clearly bounded than is a person, but even it gets fuzzy in some ways.
A living thing can be discontinuous, as can information processing.
I don't think the point is particularly important to this topic.

— boundless

Bernard D'Espagnat distinguished two senses of objective. 'Strongly objective' is something that is independent from any cognitive perspective (a property of the 'world in itself').

Calling it 'the world' is already an observer bias.

'Weakly objective' is something that every cognitive agent can agree upon. Nothing weakly objective can be assumed to be strongly objective.

Terminology granted, but both seem to contrast 'objective' with 'subjective', as opposed to objective vs relational.
The first means it relates despite not being seen (like say the far side of the moon, at least until the 60's). The latter is more of a property: It's there period vs it's there relative to something else. 37 exists, vs 37 is a member of the set of integers. That's different than 'we both can count to 37'.
I kind of irks me that 'objective' has two distinct meanings here, both quite relevant.

But what is an idea, but an idea of something. Like a word, an idea, sitting in the mind, is about something "already there" before the idea of it was formed. — Fire Ologist

Often, yes, but sometimes and idea is of something not already there. Any fiction for instance.

I do not support "mind-independent reality?" But I must say I do not understand anything you said. — Athena

As I said above, the title is poorly worded. My focus is on those that posit a mind-independent reality (which is almost everybody except idealists), they tend to restrict their idea of what exists to 'this universe', calling 'the universe' instead of just one of many. Why is this one special? Because it is observed (by us) of course, which makes it pretty mind-dependent in my book.

Now how to convey that in a short title?

All of reality is a reaction to what is.

Reality is defined as 'what is' (or not), so not sure how reality is a reaction to itself.

All things are a matter of cause and effect.

The number 17 doesn't seem to be a matter of cause & effect. It's just a member of the set of integers. You might say it is but an abstraction, but I think it is far more fundamental than that.

as they both agree the idea of addition also must exist in each other's minds; it's the same addition each sees separately, in each other's minds, in 2+2 and in 3+17. This is both mind-independent (shared between two different subjects), and only there because of the minds that know addition.
— Fire Ologist

OK, but mind-independent only in the sense of "not confined to my mind." It doesn't tell us whether these intersubjective sharings are mind-independent in the sense of "about something that exists regardless of whether either of us has the idea of it." — J

I never realty understand these conversations. Before anything on the planet, possibly in the universe, existed that had even the vaguest hint of understanding of mathematics, there would have been any number of instances when groups of objects joined together. Rocks rolled down a mountain, and came to rest among other rocks. Leaves fell from plants, and landed interspersed with each other. Whatever scenario. My guess would be that, despite there being nothing in existence that could count or add, in none of those instances was the number after the groups combined anything other than the combination of the numbers of the separate groups.

Ironically, Wittgenstein's Tractatus can also be invoked to support the view that one can't go outside one's perspective (see TLP 5.6-5.641...here a link). And in fact, one can cite the later Wittgenstein's view that sense can be pragmatic in nature. Even if my picture is wrong, then, if it still has pragmatic use, I don't see why it would be 'nonsense'. — boundless

I think these sections are serving the purpose of putting the implications of Wittgenstein view of language and how we make sense of the world, deciding on what can be said and what can be shown. In these sections, solipsism is not something that can be said, but only shown.

5.64 Here it can be seen that solipsism, when its implications are followed out strictly, coincides with pure realism. The self of solipsism shrinks to a point without extension, and there remains the reality co-ordinated with it.

In H.O Mounce’s Wittgenstein’s Tractatus An Introduction, puts it nicely when he says, “For the solipsist in wishing to deny the independent reality of the world, in maintaining that only he and his ideas are real, has the idea of his self as an object standing, as it were, over and against an unreal world. But when he realizes the confusion in this, when he sees that there can be no such object as he takes his self to be, the world reappears as the only reality in which his self can manifest itself.”

I believe that one has to take seriously his discussion in the whole section. He uses the example of the eye and the visual field to explain why there is no 'subject'. Nothing in the visual field suggests that there is an eye. So, in the same way, nothing in the 'empirical world' suggests that there is a 'self'. The 'self', according to Wittgenstein, would be 'outside' the world. But if it is outside the world, and if meaningful propositions are about the empirical world, then, of course, one can't make any meaningful proposition about the 'self'.

Still, yes, Wittgenstein says that solipsism comes to coincide with 'pure realism'... but the 'world' in the Tractatus is the purely empirical world of fact, which is 'seen' in a particular perspective, which means that it is perspectival. So, I am not sure that the 'realism' LW had in mind is the realism most philosophers had in mind.

IIRC, if I recall correctly, the later Wittgenstein rejected the early Wittgenstein's assumptions that (1) meaningful propositions must have an empirical content, (2) there is a structural correspondence between the structure of (ideal) language and the structure of the world and (3) there are atomic propositions, which correspond to the 'atomic' facts. Also it is the later Wittgenstein that rejected solipsism by alluding that language can't be private. He also arrived to an interesting notion of 'certainty' which seem to very different from the earliest views, i.e. the notion that certain 'hinge propositions' can't be doubted if we want to function. We do not doubt them becuase, if not, we could not make sense of our experience and we could not function (for instance, when I go to sleep, I do not have the doubt that I wake up on the other side of the world) even if strictly speaking we can't have a 'indubitable certainty' about them (in my example, I could be kidnapped while sleeping and taken to other side of the world... still, I don't doubt that I'll wake up in my bed. If I did, I could not think about my future in a functional way).

The later Wittgenstein notion of certainty, however, doesn't seem to be what most earlies philosophers had in mind when they thought about certainty and knowledge. It's a provisional kind of certainty.

I think the disagreement is that what you are attacking is some kind of unique objective description of the universe (e.g. Newtonian mechanics, falsely speaking). However, from the beginning of the conversation, I have just been talking about information about the world we gain from perception or observation. And we may put boundaries around objects in perception in different ways if we really want to; but, nonetheless, what appears on our retinas and other sensory boundaries are patterns that map to events or structures out in the world, mostly in a consistent manner. And this kind of consistent mapping (at least in some restricted relevant context) I think is actually the minimal requirement for pragmatism and use. — Apustimelogist

IMHO philosophical realists assume that we can describe the 'mind-independent world'. For instance, Galieleo and Descartes assumed that while the 'secondary qualities' of the objects (colours, sounds, tastes etc) are mind-dependent, the 'first qualities' are intrinsic properties of the physical objects.

If you say that even in principle, we can't have a 'faithful description' of the 'mind-independent world', then, one can't be a 'realist' in most meanings of the term*. Bernard d'Espagnat used the term 'open realism' to denote the minmal position where a mind-independent reality is assumed but without any claim of descriptive knowledge. Not just pragmatic one.

*Generally the term realism refers to the views in which we have at least the possibility to make a description of the world.




Some time ago, I mentioned the distinction of the 'two truths', which is prevalent in Indian philosophies but actually also appears in western philosophy.

On one hand, we can talk about 'provisional truths', which are pragmatic. For instance, "The Sun rises in the east and sets in the west" is true in a provisional sense. But it also isn't true, right? We know that it is not a correct description of what 'really happens'. It's certainly useful and it correctly describe our observations. But we can't take literally this statement.

On the other hand, 'ultimate truths' would be correct statements that in some ways describe how the world is 'in itself'.

So, if we allow that the knowledge of pragmatic truths is indeed 'knowledge' then of course we can talk about knowledge. But if by 'knowledge' we mean unmistaken knowledge, or the knowledge of how the world truly is in itself, I am not sure that we can have this second kind of knowledge.

OK, I think I worked it out. You're talking about Wigner's opinion of what the friend has measured while the friend is still in the box. That's a clear counterfactual, and unless an interpretation is used that posits counterfactuals, there is no 'truly' about it. RQM does not posit counterfactuals. — noAxioms

No, I was thinking also about what the Friend measured after he exited the box. Rovelli actually brilliantly paraphrased his views like this: "More precisely: everybody hears everybody else stating
that they see the same elephant they see. This, after all,
is a sound definition of objectivity." (source: https://arxiv.org/pdf/quant-ph/0604064, pag. 7). Wigner hears his Friend stating he saw the same thing Wigner observed. But this is not a way, for Wigner, to go outside Wigner's perspective.

No, not at all. Existence of anything is relative to that which has measured the thing, and so far, our 'perspective bearers' have not been measured. They will momentarily, but then they're not the perspective bearers anymore, they're the observed. — noAxioms

Not sure if I understand you. When Wigner and the Friend meet, their interaction is (also) a measurement. So, the state of the Friend is 'measured' by Wigner. Does this mean that the Friend loses his status as a 'perspective bearer'? You can't define a perspective of the Friend?

Quite the opposite. Where are you getting all this? — noAxioms

If I say that my knowledge is restricted to my own perspective, how can I claim there are other perspectives and there are no perspective-independent things?

According to RQM, their ontology relative to Wigner is a superposition of states. According to other interpretations, the ontology is different. Ontology seems to be a mental construct, a function of say one's choice of interpretation, but it also might be a physical mind-independent status, depending on which (if any) interpretation is actually the case. — noAxioms

Ok

Are you suggesting that Wigner isn't sure that the friend is like himself? That Wigner cannot discard solipsism? I suppose that's correct, but it's not considered a valid quantum interpretation since it leads to zero knowledge of anything. Ditto with superdeterminism, a loophole in Bell's proof, but you still don't see it included in the interpretations list. — noAxioms

More or less, yes. Note that my point isn't about only RQM. But all models who claim that knowledge is perspectival.

But also note that our knowledge seems to be perspectival. Wigner can't 'see' the world from the Friend's perspective in order to confirm his belief that, indeed, the Friend is, as you put it, like him. This is so precisely becuase Wigner's knowledge is limited by his perspective. So any claims that he makes about anything outside his perspective can't be confirmed. And yet, as you say here, this 'epistemic solipsism' seems to be self-refuting for various reasons. So, he has good reasons to believe that there is something outside his perspective, that there is a real intersubjective agreement (in a sense we do really see the same elephant albeit possibly in a distorted way, and we don't merely hear others say that they see the same elephant) and so on. But IMHO this 'certainty' is IMHO grounded if we assume that there is a 'mind-indepedent reality' or, in general, 'a reality independent of any perspectives'. But we can't verify this assumption.

I see this as an antinomy.

Yes. I am not using any of those words as something requiring a human or other 'observer' to be involved. — noAxioms

Ok! Don't think my points would change much anyway.

I don't understand that problem enough to have an opinion about how problematic it is or to critique any solution proposed or counter-critique.
I said I don't buy it for different reasons than it offending my delicate sensibilities (the argument put forth in the Bell paper linked by the most recent post by Wayfarer. — noAxioms

Ok, thanks!

Calling it 'the world' is already an observer bias. — noAxioms

Why?

Terminology granted, but both seem to contrast 'objective' with 'subjective', as opposed to objective vs relational.
The first means it relates despite not being seen (like say the far side of the moon, at least until the 60's). The latter is more of a property: It's there period vs it's there relative to something else. 37 exists, vs 37 is a member of the set of integers. That's different than 'we both can count to 37'.
I kind of irks me that 'objective' has two distinct meanings here, both quite relevant. — noAxioms

Yes, both terms contrasted objectivity with subjectivity. Not sure about the distinction you make here. Are you saying that a better distinction would be between "what is independent from any relation" vs "what is relation-dependent"?

I'm going to arrogantly say very little and assume I've solved all the thread's problems.

1 ) Physical != preceded by an event, the timing of beta decay events is random, they only have a cause in an abstract sense rather than a preceding event sense.
2) Preceded by an event != caused, even in how we use cause in explanations. People want to say things like "the tendency of a system towards its ground state causes...", even when that's not talking about a precedent event, it's talking about a "law" {an abstract generality} causing an event {a concrete particular}
3 ) Mathematised != determined, compare Norton's Dome in Newtonian mechanics {arbitrary rolling point} and any quantity associated with a distribution {anything that can be represented with a wavefunction has a wavefunction squared...}
5 ) Measurement != thought, OP grants this, so already undermines the premise in the title. This already means measurement dependence does not negate mind independence.
6 ) Physical != part of a mathematical model, like bouncing balls' amplitudes following a geometric decline only stopping in the limit.
7 ) Physical != part of a physical theory - maths objects are parts of physical theories, but not physical in the same way as quarks and chairs. The way in which an integral transform is part of a physical theory is different from the way in which an electron is, and it's this latter difference in sense that determines what is physical and what is not.
8 ) Relational != causal - come on you lot, an electron's trajectory through space is related to is charge, but its charge doesn't count as an event, so doesn't count as a cause. In the specific context of a measurement fixing an entire history of what's measured, it fixes the history of interactions, and you're going to need to equate interaction with relation with causality through some other set of arguments if you want to say relational = causal on this basis.

I believe that one has to take seriously his discussion in the whole section. — boundless

Indeed, and one should take seriously the point of the whole book. That is to distinguish between what has sense and what is nonsense, what can be said and what is shown. To draw the limits of language and remain silent, to say nothing except what can be said.

“6.53 The correct method in philosophy would really be the following: to say nothing except what can be said, i.e. propositions of natural science—i.e. something that has nothing to do with philosophy—and then, whenever someone else wanted to say something metaphysical, to demonstrate to him that he had failed to give a meaning to certain signs in his propositions. Although it would not be satisfying to the other person—he would not have the feeling that we were teaching him philosophy—this method would be the only strictly correct”

So solipsist asserting “they alone exist in the world” or any other such permutation, asserts nothing all at.

As for later Wittgenstein, while his approach differs from his earlier work, would be equally dubious of the solipsists assertions, This was done by showing how the solipsist abuses our ordinary use of language.

I think though that just because we do not have a unique, objective "god's eye view" though, doesn't mean that the information we obtained in any given perspective cannot reflect genuine information that consistently maps to the world with consistent relationships to other parts of the world. That is how perception works. And in some sense I think descriptions are second order - putting boundaries around "things" and giving them names is second order. If anything, pointing at and giving "things" names is more of a metacognitive description of my own perceptual abilities - I am describing or pointing out my own ability to make distinctions.

What is first order is perception itself, which reflects real information about the world directly in your perceptual experiences, without having to put a boundary around or label something. I don't need words to catch a ball, I don't necessarily need the concept of a ball to catch a ball; nonetheless, I am engaging with real information about and mapping to the world. It just happens to be information through a limited purview.

I would argue that a big reason why there are different purviews - that is not strictly about mind-dependence - is simply because we have physical structures that relate to other structures in the world in specific ways (e.g. the structure of our eyes and how they interact with light which interacts with other objects). Obviously though, even with physical similar capabilities, different animals may be better at abstracting patterns from sensory information. Is this a kind of mind-dependent confabulation or a detection of actual statistical structures in the world which are captured in our perceptual tools? Or some animals just cannot abstract certain kinds of relationships between percepts from the world.

Now, I would say that obviously, a brain dping statistics depends on the brain's capabilities, so it is mind-dependent in that sense. But, if there are some kind of criteria where one can evaluate through perception a correctness in detecting or mis-detecting higher-order patterns, and some kind of consistency in which one can react and behave and which they relate to other parts of the world, then surely these actually reflect some kind of meaningful structure out in the world that makes a difference, even if this structure is inherently fuzzy and perhaps convoluted.

What I would say is that we can make valid distinctions about the world which are meaningful in terms of consistent relational structures; but at the same time uphold a pluralism. There are many different ways we can partition the world statistically - infinitely many, perhaps. But surely, if one can engage with and distinguish these structures in a way that is consistent, then these cannot be arbitrary. The only reason I can make arbitrary boundaries around objects in my perception is because I can actually distinguish structural information about the world in my perception in order to draw those boundaries. And I don't think we even draw strong boundaries anyway really - the idea that we kind of have this rigid repertoire of concepts which we apply to the world is an idealization imo. Anyone tomorrow could invent an entirely new conceot or objects which is physically meaningful and catches on for one reason or another.

Yes, one could say conceptual pluralism is just anti-realism; at the same time, our engagement with the world is arguably real - or at least, if I were to tell a story about how we do that, it would have to be in some sense "real" - and putting into use these concepts may be enacted in some real engagement with the world, or the structure that comes at us directly in perception that maps to the world.

I guess question is about how apt a description being "mind-dependent" can be if it is clearly non-arbitrary. You could call the drawing of a boundary itself arbitrary, but if I can repeatedly identify this bounded "thing" in perception that comes up again and again due to information from the world at my sensory membranes, then is this really non-arbitrary?

If uniqueness of description is a criteria for realism then sure these things are very problematic. But why does uniqueness have to be a criteria for realism? You can say describe theories in multiple different ways or formulations which are deemed as equivalent in a way that people would just say its multiple descriptions of the same thing. Thats not to say that you couldn't argue there are non-trivial differences that distinguish them, but maybe there is no definite boundary of when different formulations are part of the same theory or different theories. Someone could arbitrarily decide formulations are different based on what others deem a small trivial difference. Like in the description of bounded objects then, perhaps the boundaries between saying "different" vs. "the same" are complicated graded structures of difference and similarity over different scales. Once there is this arbitrariness in saying some things are "different" or "the same", then its not clear there is a definitive way of sying whether a plurality of descriptions should be deemed indicativeness of real or non-realness. The whole issue might be deflated. "real" is a second-order description we apply to structures that we come across in percepts, make inferences about.

Yes, you could use indeterministic pluralities to say things are not real. Perfectly valid if you have your own criteria for saying something is real or not - i.e.it must be unique.

What is interesting to me though is why these arguments have little or no effect on realists often. It seems from reading that realists actually have moved their goalposts, based on anti-realist arguments like underdeterminacy and the potential prospect of things like scientific theories being wrong. But then you have to ask what it is that realists cling to - and I think it is this very fact that, regardless of the kinds of pluralities and indeterminacies and fuzziness, there is still this kind of non-arbitrary nature of our perceptions that map to some structure in the world and we engage with. You could say our descriptions are not real but it seems superficial when we can still engage with the world perfectly well. Obviously some descriptions are obviously wrong - which then occurs when our engagement with the world results in errors. But I would say errors is not so interesting to arguments on realism. Everyone can plausibly be wrong; anto-realists can probabilistocally be vindicated in the beliefs that there is more to learn, that theories are idealizations ans incomplete, that some past theories are outright wrong. Maybe some current theories too if we find new predictions. But then again, unless they make additional metaphysical claims someone can still claim a theory is still valid in some purview even if it does not capture the world uniquely - Classical physics is still widely used because it captures and describes relational structures we can engage with in the world without needing to make excess metaphysical assumptions. The question is whether it is impossible in principle to have a meaningful, consistent engagement with the external world, which we can do from various purviews without comong up with errors. If we have a plurality of ways of describing the world that don't come up with wrong predictions, does that mean none of these things capture real structure in the world?

But at the end of the day, from my perspective, yes this perceptual thing may be a bit too minimalist for realism from the perspective of anti-realists. But I think the issue of pluralities could come under attack for being weak by realists and at the same time if you are something like Van Fraasens form of anti-realism then this issue comes up for empirical perception not just theories - e.g. theory ladenness. But then, how can we engage with the world so well when even perceptual categories are idealizations and theory-dependent and even wrong.

I think the whole issue should be deflated maybe since the coarse distinction of real vs non-real doesn't adequately reflect the subtlety and nuance when it comes tothe balance between arbitrary boundaries and yet our very real, skillful engagement with the world regardless of such boundaries. Descriptions are red-herrings if we inflate them because really all there is is perceptual experiences in flux - we engage with structural information from the world in our senses constantly and we instrumentally, enactively use that information to guide our actions. Even a description may just be indicative of a metacognitive ability to make higher-order inferences about our own epistemic actions - the behaviors of thought and perception. We are extremely complicated machines that far outstrip literal words and descriptions in our epistemic activities and perceptual abilities. In some sense then all descriptions are "not real" because they can be deflated in this sense. Yet there is a mins-independent world and we engage with it to prosuce the useful behaviors that constitute knowledge, even when our abilities actually outstrip our descriptions. My ability for instance to distinguish different faces far outstrips any use of words I could make up to classify them - apart from the use of proper names which don't even have a description attached (i.e. they are effectively just pointing).

Maybe though the realist is just moving the goalposts for "intrinsicness" but then I guess the realist would also say that standards of intrinsicness that are too high are vacuous. We could plausibly say nothing is real because no descriptions, not even perceptions satisfy some ultimate criteria of intrinsicness (e.g. vision would have to be independent from any perspective, any brain, any intermediate physical process)

But then what is the outcome of saying nothing is real? The paradox that a world where nothing is real often seems perfectly coherent.

There is even a pragmatic limit to anti-realism in some sense.

But even then that depends on intuition since some people just don't have that intuition and they think some notion of anti-realism intuitive makes sense. The issue is we can gerrymander these borders of realism and anti-realism very easily without them having strong, consistent empirical consequences everyone can agree on like in everyday life or sciences or archaeology. And obviously this is graded. Maybe discussions about realism and anti-realism are just naturally inclined to kinds of contextual paradoxes almost - at least, if nothing is real, then "anti-realism" is also a false label. The problem is that usually when we sraw boundaries around objects, they aren't usually mutually inconsistent; but we have decided such for realism and anti-realism even though what is more apt may be some kind of gradation. Is "real" a label for a certain kind of abstract consistency in our experiences, in contrast to misapprehension? Its about intrinsicness? But maybe only kind of intrinsic things about fundamental reality that are intelligible are structures in some weak sense - and there is nothing more from the perspective of intelligibility or meaningfulness. But that is a significantly weaker sense of intrinsicness given the structure is weak and has a perspectival aspect. But neither would I say it is viewing the same thing from different ways (in a subjective sense). Rather we can view overlapping structures within reality on our sensory boundaries. Maybe those two statements can be seen as equivalent though.

Maybe what I have done is shifted something that an anti-realist would not view as intrinsic (i.e. perceptual, empirical observation - perceptual, empirical structure) and upgraded it to something that mediates intrinsic information.

I think my perspective is similarish too Otavio Bueno's structural empiricism masquerading as a very weak ontic structural realism... so weak that they are interchangeable. This comes from my anti-realist inclinations to deflate thingsbut the desire to acknowledge mind-independent reality in a way that is not divorced from what we do and think - realism should be in the story, at least for a person that wants to assert things about the world, or have theoretical preferences, even if they may be incorrect.

Part of what has been learned is the incredible unlikelihood of our universe's fundamental constants being what they are — noAxioms

. . . according to a specific mathematical model that if it isn't actually showcased within the confines of our accepted empirical assumptions/guidelines to be ever potentially even falsifiable for centuries to come then it will only become more under-determined.

A lack of observational support does not stop people from constructing further models which are in principle unfalsifiable, practically unfalsifiable, or ones with adjustable parameters which only grow more indistinguishable from the accepted with every new observation.

Which makes the 'unlikelihood' of our universe arising from random chance depend on the current models one may adopt or might come about within a hundred years or so of empirical stagnation.

___________________________________________________________________________________

There is a danger here because you need to distinguish between what things that you could potentially 'inter-translate' between the language used in idealism or realism and what is incommensurable.

I can always create an uninteresting rival to a particular idealism or realism by simply renaming terms and redefining meanings. You say 'idea' and I say 'physical'. You say 'inter-subjective' and I say 'objective'.

Following the lines of reasoning from deflationist you could then see this as merely semantic pontification. However, if there is a some term which either side agrees is not so easily inter-translated that could then imply some kind of substantive disagreement or discussion. That doesn't mean that one side gets the ball but rather there is a debate to be had here about how, in their own respective languages, they should expand the concepts they use and also how to translate them to each other.

My prior topic attempted to illustrate the lack of justification of mind-independent reality. Campbell here seems to imply that it is a strong human need to find one, but in the end, as my other topic poorly found out, it cannot be justified. It is what it is, and what it is is apparently what we say it is. — noAxioms

It's like how a skeptic will always find holes in the arguments I give to not drink bleach. . . alas. . . I still decide not to.

For communication to occur (the primary function of language-use) it would do the speaker or writer good to understand the language understood by their listeners and readers, as well as the level of understanding of the language. What would you hope to accomplish in talking about quantum physics to a 4 year old, or publishing a book written in Spanish in Russia? The relativized nature of language disappears when it is actually used to successfully communicate. You could say that the relativized nature of language only appears when miscommunication occurs. — Harry Hindu

Ergo, we should all be deflationist about philosophy as much as we can until we can't and diagnose the translation issue. It's no longer the era of idealism vs realism but rather a debate about what terms in each respective philosophy are incommensurable and which are not.

So when an idealist blabs in your ear is what they are saying uninteresting and intuitively obvious to you or is it conceptually new. I.E. something that under your notion of a respectable realist position they could not reformulate in their words/concepts/meanings the same notion.

I don't think that scientific knowledge alone can give us a definite answer about this question. This would imply that we have to 'suspend judgment' about how our models can 'reflect' the structure of the world and admit that, in fact, we have no way to make sure claims about our own cognitive perspective. — boundless

. . . BUT despite that skepticism. . . despite that under-determination. . . despite that lack of truthful absolute justification. . . you and I will probably retain many of these biases of the manifest image out of mental inertia, bias, dogmatism, apriorism, and moorean intuitionism.

That is because realism is a mental perspective which cannot be proven or disproven. . . only HELD or NOT HELD. Whether you hold to a particular form of realism or idealism will probably not impact much of anything as the direct nuts and bolts pragmatism of advancing science requires.

However, perhaps they are then not to be seen as such grand ontological positions but as political positions which can influence the mind in what kinds of connections you can make conceptually. Who is to say that the obscure idealism might be able to make some abstract connection that some form of realism would have not found out for a long while or as easily. Again, that isn't to say that other form of realism would have eventually come to the same conclusion but if its a question of efficiency in generation of novel ideas then. . .

I think Wittgenstein’s Tractatus may offer a solution here. That is in order for us to make sense of the world, that is to avoid speaking non sense, our language, mental construct, and the world must be isomorphic. This is not an outcome of empirical verification but of logic analysis. — Richard B

Yes. . . but that is easier said than done.

I never realty understand these conversations. Before anything on the planet, possibly in the universe, existed that had even the vaguest hint of understanding of mathematics, there would have been any number of instances when groups of objects joined together. — Patterner

Not contesting that. What I am contesting is that it wasn't 'the universe' until those 'understanding' things designated it as such. Without said observation, it is merely 'a universe', not the preferred one.

In H.O Mounce’s Wittgenstein’s Tractatus An Introduction, puts it nicely when he says, “For the solipsist in wishing to deny the independent reality of the world, in maintaining that only he and his ideas are real, has the idea of his self as an object standing, as it were, over and against an unreal world. But when he realizes the confusion in this, when he sees that there can be no such object as he takes his self to be, the world reappears as the only reality in which his self can manifest itself.” — Richard B

That actually speaks to me, even though I think I'm interpreting these words in a different light than was intended.

Some time ago, I mentioned the distinction of the 'two truths' ... — boundless

I reference something like that all the time, separating pragmatic truths from the rational ones.

For instance, "The Sun rises in the east and sets in the west" is true in a provisional sense. But it also isn't true, right? We know that it is not a correct description of what 'really happens'.

In the right reference frame, it is what happens, but it's still a provisional truth in that frame. I don't think what you call 'ultimate truths' are frame or perspective dependent.

On the other hand, 'ultimate truths' would be correct statements that in some ways describe how the world is 'in itself'.

The bolded bit is such a perspective reference, and illustrates the point of this topic.

No, I was thinking also about what the Friend measured after he exited the box. — boundless

The friend is almost immediately entangled with the spin-measurement device, so he's going to match that every time, whether or not Wigner has measured the friend yet or not.

Rovelli actually brilliantly paraphrased his views like this: "More precisely: everybody hears everybody else stating that they see the same elephant they see. This, after all, is a sound definition of objectivity." ... Wigner hears his Friend stating he saw the same thing Wigner observed. But this is not a way, for Wigner, to go outside Wigner's perspective.

Interesting that Rovelli phrased it that way, but if it were not true, the view would be falsified. The statement is true of quantum mechanics and not just any subset of interpretations.

Note a definition of objectivity which isn't 'relation independent' nor is it 'not subjective', but rather it is objectivity defined in terms of intersubjective agreement. In the case of RQM/MWI, objectivity is being defined as mutual entanglement.
Using such a definition, I yield the factualness of the objective existence of the apple.

When Wigner and the Friend meet, their interaction is (also) a measurement. So, the state of the Friend is 'measured' by Wigner. Does this mean that the Friend loses his status as a 'perspective bearer'?

No, it just means that the friend event that Wigner measures is a different perspective than the Wigner event doing the measuring. That friend perspetive event cannot measure the Wigner event in question since said Wigner event doesn't exist relative to the friend event in question.

Note my use of 'event' here since each event on one's worldline is a different perspecitve.

Also, it makes the assumption that its truth is perspective-independent. — boundless

Quite the opposite. Where are you getting all this? — noAxioms
If I say that my knowledge is restricted to my own perspective, how can I claim there are other perspectives and there are no perspective-independent things? — boundless

Knowledge is not the same as truth. Sure, knowledge seems perspective dependent, which is why we don't know where the nearest alien intelligence is.
Maybe you define truth in a relational sort of way: It's true that the moon orbits Earth each 27 days. That's a relational fact, but not a fact.

Are you suggesting that Wigner isn't sure that the friend is like himself?

More or less, yes. Note that my point isn't about only RQM. But all models who claim that knowledge is perspectival.[/quote]RQM (like almost all ontic interpretations) doesn't treat any person different than another. It doesn't even treat pens differently than people.

But also note that our knowledge seems to be perspectival. Wigner can't 'see' the world from the Friend's perspective in order to confirm his belief that, indeed, the Friend is, as you put it, like him. This is so precisely becuase Wigner's knowledge is limited by his perspective.

This is philosophy of mind, which of course has no resolution. Sure, but we're presuming sufficient mind-independence to suspect one person's experience is functionally similar to any other.

Calling it 'the world' is already an observer bias. — noAxioms
Why? — boundless

The syntax suggests that this world exists to the exclusion of any other, all because it's the one we see. A far less mind-dependent wording would be 'a world' which doesn't carry any implication of being the preferred world.
My whole topic contrasts 'the world' with 'this world, among others', with the former implying mind-dependence.

Are you saying that a better distinction [of 'objective'] would be between "what is independent from any relation" vs "what is relation-dependent"? — boundless

Different, not necessarily better. Best to define how the word is being used up front when wielding it.

I'm going to arrogantly say very little and assume I've solved all the thread's problems.

1 ) Physical != preceded by an event, the timing of beta decay events is random, they only have a cause in an abstract sense rather than a preceding event sense. — fdrake

Almost all events are preceded by prior events. Not sure what that has to do with uncaused occurrences like beta decay. A few interpretations have it being a caused (determined) thing.

2) Preceded by an event != caused, even in how we use cause in explanations. People want to say things like "the tendency of a system towards its ground state causes...", even when that's not talking about a precedent event, it's talking about a "law" {an abstract generality} causing an event {a concrete particular}

OK, This seems to say that 'laws' don't count as causes.

3 ) Mathematised != determined, compare Norton's Dome in Newtonian mechanics {arbitrary rolling point} and any quantity associated with a distribution {anything that can be represented with a wavefunction has a wavefunction squared...}

Agree. The Dome thing is a wonderful example of an uncaused occurrence in Newtonian mechanics (which demonstrates that it isn't deterministic as claimed).

5 ) Measurement != thought, OP grants this, so already undermines the premise in the title.

Title is poorly worded, mostly due to lack of being able to express a correct one in a short line.

6 ) Physical != part of a mathematical model, like bouncing balls' amplitudes following a geometric decline only stopping in the limit.

Sorry Zeno :(

7 ) Physical != part of a physical theory - maths objects are parts of physical theories, but not physical in the same way as quarks and chairs.

But the quarks possibly supervene on maths objects. That doesn't make said maths physical in the same way, I agree.

8 ) Relational != causal - come on you lot, an electron's trajectory through space is related to is charge

An electron trajectory though space is a counterfactual.
You seem to be using 'event' differently than I. I use it to mean a point in spacetime, or possibly (more informally) a system state at a moment in time, also known as a beable.
The relational ontology I've been discussing is pretty dang causal in definition.

Not sure what problems you think were solved by these numbered assertions.

Which makes the 'unlikelihood' of our universe arising from random chance depend on the current models one may adopt or might come about within a hundred years or so of empirical stagnation. — substantivalism

Sure. Some models have good odds, and others have really low odds.

It's like how a skeptic will always find holes in the arguments I give to not drink bleach. . . alas. . . I still decide not to. — substantivalism

But the bleach thing at least has an argument, even if the argument isn't perfect.

I never realty understand these conversations. Before anything on the planet, possibly in the universe, existed that had even the vaguest hint of understanding of mathematics, there would have been any number of instances when groups of objects joined together.
— Patterner
Not contesting that. What I am contesting is that it wasn't 'the universe' until those 'understanding' things designated it as such. Without said observation, it is merely 'a universe', not the preferred one. — noAxioms

The syntax suggests that this world exists to the exclusion of any other, all because it's the one we see. A far less mind-dependent wording would be 'a world' which doesn't carry any implication of being the preferred world. — noAxioms

I don't know what to make of this. I can talk about the fork I used at dinner without meaning it's the only, or the preferred, fork. If it was my turn at bat, I wouldn't ask the ball boy for a bat, because he needs to knows which one. There are many, but I need to specify. And I'll be in all kinds of troubles if someone asks what I'm doing this weekend, and I say, "I'll have to ask a wife."

The universe I'm in may or may not be the only universe. But it's the only one I have any experience of. If I start talking about "a" universe, people will be confused. They'll probably stop me and ask what I mean by "a".

@substantivalism @apokrisis

New theory of entanglement - Persistence Theory, Bill Gianokopoulos (Profile)

Spooky Action at a Distance, Reversed: Entanglement as Collapse of Mutual Information (via Medium).

// for anyone interested, an AI chat about this article and its implications - comparisons with Peirce's pan-semiosis and Wheeler's 'it from bit'.//

The problem with Wittgenstein's tractatus is that if the 'ending' (TLP 6.53-6.54) are taken at face value, Wittgenstein at the end argued that no metaphysical position is tenable and even the Tractatus itself at the end of the day is inconsistent (a conclusion that makes sense, after all. If one believes that in order to be meaningful, propositions must be about some empirical facts, the Tractatus' proposition have no empirical content, then...).

What Wittgenstein seemed to argue in the 5.6s sections is that while the 'world' is presented in a particular perspective, the 'self' doesn't appear 'in the world' and so anything we say about the self would be nonsensical. To me, the early Wittgenstein had a very idiosyncratic idea of what realism means.
To put in another way, the 'world' for Wittgenstein is the totality of what can be known. The knower would be outside 'what can be known' and, being outside, the knower can't be known and, therefore, nothing can be said about the knower, because anything we could say would be meaningless.

Given that Wittgenstein speaks about the world in empirical terms, can what he is saying help us to understand 'how the world is outside experience'. I don't think so. For him it would be what can be known/said.

In the right reference frame, it is what happens, but it's still a provisional truth in that frame. I don't think what you call 'ultimate truths' are frame or perspective dependent. — noAxioms

Right! Can we talk about a 'realism' without 'ultimate truths' or the possibility to know them?

The bolded bit is such a perspective reference, and illustrates the point of this topic. — noAxioms

Sorry, I am not trying to be dense. But I'm not sure about what you are getting at. I would say that usually realism involves that the world can be known, at least in priciple, as it is independently of any perspective of any subject.

The friend is almost immediately entangled with the spin-measurement device, so he's going to match that every time, whether or not Wigner has measured the friend yet or not. — noAxioms

Yes. But this doesn't deny the fact that Wigner and the Friend's perspective are different. And neither can actually 'take the other's perspective'.

Interesting that Rovelli phrased it that way, but if it were not true, the view would be falsified. The statement is true of quantum mechanics and not just any subset of interpretations. — noAxioms

Yes. Some interpertations however claim that they are 'ontologically interpretable' (to use a phrase by d'Espagnat), in the sense that they can be read as providing a correct description about the world as it is in itself.

Rovelli is saying that each 'observer' can't go outside 'his' own perspective. 'He' will never find any inconsistencies because all data 'he' will be able to find will be consistent 'for him'. But if 'his' knowledge is limited by 'his' own perspective, then, he can't actually know what 'others' observe. He just can verify that when 'he' asks 'them' what 'they' did 'observe', 'he' finds no inconsistency. (I am using the scare quotes because I want to allow the possibility here that the observer might be a physical system).

RQM (like almost all ontic interpretations) doesn't treat any person different than another. It doesn't even treat pens differently than people. — noAxioms

Fine. My point above would still stand.

The syntax suggests that this world exists to the exclusion of any other, all because it's the one we see. A far less mind-dependent wording would be 'a world' which doesn't carry any implication of being the preferred world.
My whole topic contrasts 'the world' with 'this world, among others', with the former implying mind-dependence. — noAxioms

Ok. But oddly enough I would say that if there are 'as may worlds as perspectives' then the presence 'mind-independent reality' is more difficult to defend.

Sorry, but I'll respond to you in the next few days.

Thanks for the links.

The number 17 doesn't seem to be a matter of cause & effect. It's just a member of the set of integers. You might say it is but an abstraction, but I think it is far more fundamental than that. — noAxioms

Number 17 is not matter. Therefore, number 17 or the word "blue" can not be caused nor effect anything.

I would like to gracefully withdraw from this thread. I do not understand what anyone is saying.