I believe that d'Espagnat brillantly explains how we can understand an epistemic interpretation of QM (and how such an interpretation is compatible, in principle, with a 'realist' philosophical view)

Even within a classical, mechanicistic, approach a rainbow, obviously, may not be considered an object-per-se. For, indeed, if we move, it moves. Two different located persons do not see having its bases at the same places. It is therefore manifest that it depends, in part, on us.
...
But still, even though the rainbow depends on us, it does not depend exclusively on us. For it to appear it is necessary that the Sun should shine and that the raindrops should be there. Now similar features also characterize quantum mechanically described object, that is, after all - assuming quantum mechanics to be universal - any object whatsoever. For they also are not 'objects-per-se'. The attributes, or 'dynamical aproperties,' we see them to posses depend in fact on our 'look' at them (on the instruments we make use of and on how we arrange them).
...
And lastly, at least according to the veiled reality conception, even though these micro and macro objects depend on us they (just as rainbows) do not depend exclusively un us. Their existence (as ours) proceeds from that of 'the Real.' — Bernard d'Espagnat, On Physics and Philosophy, p. 348

Soon later:

When N observers are scattered in the fields, each one of them sees the rainbow at a specific place, different from the ones where the others see it. In fact, under these conditions speaking of one and the same rainbow seems improper. It is quite definitely more correct to state that there are N of them, and that each observer sees his own 'private' rainbow. But then, if N=0 there is no rainbow. ... If nobody were there, there would simply be no rainbow. — ibid., p. 349

As d'Espagnat himself says, of course, all analogies are limited and we know the physical causes that are necessary for a rainbow to appear. But suppose we didn't have any possibility to know about the sunlight and the raindrops. What we would know would only be the rainbows, not what is 'beyond' them.
In a similar way, in an epistemic interpretation of QM, the mathematics of QM isn't descriptive. It is more like an alogirthm that allows us to make probabilistic predictions of what we would observer once we assumed certain things. But, according to epistemic interpretations of QM, we have no description of of what is beyond the 'observed phenomena'. Does this mean that 'what is beyond' is impossible, in principle, to describe? No but we are not in the position to know.

D'Espagnat himself, in any case, in his book makes it quite clear that he thinks that there is some reality beyond phenomena but such a reality is 'veiled' and we can't know 'how is it'. It is reasonable, however, to suppose, considering the regularities of phenomena, that such a reality has some structural affinity to the 'empirical reality' that we observe. But of course, we can't 'prove' it. So, in a sense, this is speculative.

I do not deny that the interaction ends the isolation of the system. But such loss of isolation doesn't remove superposition. So, my question is: in your view, what about the other outcomes?

I do not think that anyone is proposing an ontological difference between the device and the system. Both are physical/natural.

But this is exactly the point. In standard quantum mechanics you have to point out at which point you get a definite result from a superposition of states. The problem is that if you treat both the device and the system in the same way you cannot avoid superposition. In fact, what you get is an 'entanglement' of the device and the system which leaves the total system 'device+system' in superposition.

This does give you the appearance of collapse but if you take QM literally all outcomes are real (despite the fact that it appears that only one is real). So you end up with something like MWI (many worlds interpretation).

If you do not want to go that route, you either adopt other 'realist' interpretations or you adopt an epistemic one, where the 'collapse' is simply a way to describe the change of knowlege/degree of belief of an agent after a measurement. These views do not say that mind creates reality but they recognize that we have a limitation in our ability to know the physical world. 'How the workd is' independent of any observation is not knowable.

Sure - as I already said, it’s a product of our design. In other words whatever ‘mentality’ it possesses is ours. — Wayfarer

I always wondered why people seem to miss this point. Experimental devices, computers and so on aren't different from, say, a mechanical calculator.

A mechanical calculator is 'able' to perform calculations but it doesn't 'interpret' its own operations as calculations. We, however, are able to do that. Experimental devices and computers are not really different from mechanical calculators. There is nothing ontologically special about them that would make them different from any other 'inanimate' object.

So if one accepts the idea of a true 'collapse' of the wavefunction IMO the only options are that either all physical interactions cause it (as in Rovelli's relational quantum mechanics) or that it is a purely epistemic process. Such interpretations are, in fact, more like statements on the limitations of our knowledge.

To borrow a statement of Wittgenstein's Tractatus out of context (I sort of like to do that... I believe that Wittgenstein's Tractatus is a flawed masterpiece that can be used to clarify many concepts unrelated to its own purpose) epistemic interpretations of QM try to do something like this:

What can be said at all can be said clearly; and whereof one cannot speak thereof one must be silent. — Tractatus Logico-Philosophicus, preface

(source)

Of course it is debatable that the epistemic interpretations are right but I believe that their aim is this.

Yeah, the argument is, empirical knowledge is required to prove logical or mathematical knowledge. But that doesn’t mean empirical and mathematical knowledge are the same. One must be an epistemological dualist to grant that distinction. — Mww

Well, I agree with Kant that knowledge in mathematics and logic is 'a priori'. In fact, I would even say that some knowledge of those domains is a precondition for any kind of rational knowledge. To make an example, we could not be able to know that there are 'three apples' on the table if we didn't have a concept of 'three'.
Regarding mathematics and logic I believe that my view falls in between Kant's and Plato's, if the 'Neoplatonic' interpretation about the latter is wrong, i.e. mathematics and logic study of the structure of thought but, unlike Kant, I believe that, ultimately, their timeless truths are grounded in an 'infinite Mind'. So, I am closer to the Neoplatonic or 'Theistic' view about mathematics and logic.

I suspect that’s true no matter which philosophical regimen one favors. Whether phenomena represent that which is external to us, or phenomena represent constructs of our intellect within us, we cannot say they are unconditioned, which relies on endless…..you know, like….boundless…..cause and effect prohibiting complete knowledge of them. — Mww

Agreed. I also believe this kind of thinking also perhaps inspired mystical experiences. In a certain way, seeing that anything finite seem in some way to have an 'infinite depth' seems something like a 'perennial truth', so to speak. It is compatible basically with any metaphysical position.

In a sense, yes. An empirical sense, a posteriori. In a rational sense a priori, that which is known by us with apodeictic certainty, the negation of which is impossible, is complete knowledge of that certainty, re: no geometric figure can be constructed with two straight lines. Or, all bodies are extended. There aren’t many, but there are some. — Mww

Ok, yes, I agree with that. Logical and mathematical knowledge are of a different kind of, say, empirical knowledge. But even in mathematics, we can have partial knowledge. For instance, one might know something about natural numbers while not knowing that the primes are infinite. But once you know something in that field, you can have certainty, yes.

On the other hand, I am not sure we can even know completely any phenomena. For instance, when you consider one natural phenomenon, it seems that in order to understand it you have to understand it in its own context. But the 'context' seems limitless (or 'boundless' :lol: ). So, in a sense, every phenomenon, even the simplest ones, seems to be of infinite 'depth' so to speak.

As I said, I won’t stand in your way of using perfection as a relative measure of knowledge quality. I’m satisfied with the amount we know about a thing in juxtaposition to the quality of our ways of finding out more about those things. From there, the jump to imperfect, from our knowledge being contingent on the one hand and incomplete on the other, is superfluous, insofar as calling it that doesn’t tell you anything you didn’t already know. — Mww

Fair enough. But I believe that, perhaps, the fact that our knowledge is 'contingent', as you say, means it is incomplete.
In a sense, we know nothing, because we do not have a complete knowledge of anything. But of course, this doesn't mean that we are completely ignorant.

Yikes!!! You done got yo’self in a whole heapa logical doo-doo. What are you judging the imperfect by, if you don’t know that by which imperfect can be measured? — Mww

To make an analogy in physics. No measurement device is 'perfect' but we know that all of them are imperfect and we also know that some are more or less imperfect than others.
I also know that I have doubts, I vacillate and so on.

You’d be correct in not knowing how perfect knowledge manifests in your consciousness, but you must know what the criteria for perfect knowledge is, in order to know yours isn’t that. — Mww

I disagree. As I said, once you accept that knowledge can be of better or lesser quality, it's easier to accept that our knowledge can be imperfect, despite not knowing what 'perfect knowledge' would be.

(Until recently, I actually tended to deny we have 'knowledge' at all, precisely because I assumed that 'knowledge' must mean certain, inerrant etc knowledge).

Be that as it may, and I agree in principle, how do we get to imperfect knowledge from mysterious phenomena? — Mww

I would say that you should consider my example again. We now know a lot more about, say, an oak tree than 3000 years ago. Still, neither they were completely ignorant of it nor today we have complete knowledge of it.

Another logical mish-mash for ya: take that famous paradox, wherein if you cover half the distance to a wall at a time, you never get there. Using your atomic structure scenario, if you take enough half-distance steps, sooner or later you’re going to get into the atomic level of physical things, where the atoms of your foot get close to the atoms of the wall. Except, at that level there is no foot and there isn’t any wall. And as a matter of fact, there wouldn’t be any you taking steps, insofar as “you” have to be present in order for any half-step to be taken. So it is that talking about a table at the atomic level, isn’t talking about tables. — Mww

In a sense, yeah, there is no 'foot', no 'table' and so on at the atomic level. In fact, the very fact that we perceive a 'table' is a perfect example of the regulative activity of our mind. We pre-reflectively individuate the table as a distinct, substantial object. I believe that even scientific evidence suggests that table are mere appearances. There is this marvellous 5 minutes video where David Bohm quite brillantly says more or less the same thing.

However, I do not think that the same kind of reasoning holds for living beings. Living beings are IMO distinct and substantial entities. Yet, also in their case, like the oak tree above, they are also both 'knowalbe' and 'mysterious' for us.

No that assumption is not necessarily entailed by what I said. I said the thing that calls for explanation is the undeniable fact that we see the same things in the same places and times, even down to the smallest details. The question is as to what is the most plausible explanation for that fact. — Janus

Ok, thanks for the clarification! I agree that all evidence point to the fact that there is some kind of 'external reality'. Perhaps a veiled reality, as physicist Bernard d'Espagnat would put it.

The you come up with―a fictional scenario, which it would not be implausible to think could not actually exist. — Janus

Ok but IMO it isn't even impossible in the far future.
Let's then use the example of a dream. If you bump into a wall during a dream, the wall can cause you pain and so on. Yet there is no 'wall' and even pain in a sense it is illuosory. And yet it appears to be 'real'. In a sense, appearances in a dream do have a 'degree' of reality.

Now, of course dreams aren't shared. But they show clearly that the 'way things appear to us' do not necessarily correlate to 'what is truly happening'.

What, you are not writing down your calculation or being aware of thoughts within your body, manifesting as sentences or images? — Janus

Here you are suggesting that thoughts are bodily phenomena. But our phenomenological experience doesn't suggest that. I can distinguish an internal physical stimulus and an awareness to a concept.

Let's not―the Matrix is not a feasible scenario, and hence cannot serve as a relevant examples in my view. You would need to convince me that it warrants being taken seriously in order to interest me in it. — Janus

While I agree that the 'Matrix' literally isn't feasible, I do believe that, perhaps, in the future, we might be able to produce some virtual reality environment that 'looks like it is real'.
Anyway, think about dreams...

Observing animal behavior shows us that they see the same thing in the environment, and any differences in ways of perceiving across the range of animals can be studied by science to gain a coherent and consistent understanding of those differences. We see dogs chasing balls, cats eating out of their bowls and climbing tress. We don't see animals or people trying to walk through walls. — Janus

I see your point, but IMO this doesn't show that the 'reality beyond phenomena' is more or less equivalent to 'phenomenal reality'. It is possible, however, that both we humans beings and dogs 'represent' the phenomenal world in a similar way.

I see no problem in believing in such things, but they cannot serve as a foundation for clear and consistent rational discourse, since they are by general acknowledgement ineffable, and what people say about them is always interpretive, and generally interpreted in consonance within the cultural context in which people have been inducted into religious or spiritual ideas. — Janus

I believe things are even more complex than this. Let's say, for the sake of the argument, that Advaita Vedanta has the 'right' metaphysical view. But we can't IMO arrive at that conclusion by simply making philosophical arguments or by studying the empirical reality.
At the same time, if Advaita Vedanta is 'right', then, say, Buddhism and Christianity are wrong in their metaphysical systems at least. But, again, it is not something we can be certain of solely based on philosophical reasoning.

Then, of course, there is the problem of interpretation of certain 'transcendent'/'revalatory' etc 'experiences'. We do not live in a vaccum and our judgments are also mediated by the culture we are into. This certainly adds more complexity. But IMO we can't deny the possible cognitive validity of 'experiences' of this kind only because the experiencer is influenced by his or her culture. In fact, historically, these kinds of 'experiences' caused radical cultural changes.

It is certainly an extemely fascinating and complex topic.

Okay, fair enough, but for me it is far more difficult to understand what a "fundamental mental aspect" or "divine mind" could be — Janus

Ok. So do I. But, as I said, it seems to me the best class of metaphysical models.

Yeah, I can see that. My response to the first would be there is no need to explain it, and for the second, we simply don’t know how. — Mww

Ok, but for me unless it is 'proven' that we can't know, we should seek. YMMV

Agreed. While it certainly changes, it doesn’t necessarily improve. — Mww

Right! However, to philosophy's credit, in a sense, it is less easy to know if there is progress or not, given the nature of inquiry.

We might even be able to reflect this back on the lack of philosophical progress, in that regardless of the changes in the description of knowledge, we still cannot prove how we know anything at all. I think it a stretch that because we con’t know a thing our knowledge is imperfect. — Mww

In a sense, yeah. I believe that this in fact an aporia in philosophy, in general. We are not completely ignorant and unaware. We have some degree of knowledge and awareness but we also know that they need to be improved. So, how can we trust to improve our knowledge if our faculties are limited, not completely reliable and so on?

What would perfect knowledge look like anyway? — Mww

I don't know. But I do know thay my knowledge is imperfect.

Again, the general, or the particular? The quality of knowledge in general remains constant regardless of the quantity of particular things known about. I’m not sure knowledge of is susceptible to qualitative analysis: a thing is known or it is not, there is no excluded middle. By the same token, I’m not sure that when first we didn’t know this thing but then we do, the quality of our knowledge has any contribution to that degree of change. — Mww

Well, to make an example of a natural phenomena... consider, say, a plant. If we know that the plant is born from a seed and that it reproduces we know little of the plant. In fact, even if one studies all the biological knowledge we have about that plant, something is still missing. For instance, we do not know every single cause that brought ultimately to the existence of that particular plant. In a sense, all phenomena are mysterious for us. And yet, we do have some knowledge and our knowledge today of, say, biology is better than it was 3000 years ago.

Even if your idea revolves around the possibility that because our knowledge is imperfect there may be things not knowable, which is certainly true enough, it remains that there are more parsimonious, logically sufficient….simpler……explanations for why there are things not knowable. — Mww

My point is more like the above.

To make another example. Consider a table. Even if we knew its composition at its atomic level and how the 'table' emerges from that composition and the interaction between its atoms, it would still be the case that we do not 'fully' know the table in a sense.

Note that this is true even if you have a 'direct realist' view... of course, when one takes into consideration that there is also the interpretative and regulating role of the mind (with the term 'mind' here I include all our faculties: sensitive, intellectual etc), everything is in a sense even more 'deeper' and mysterious. But neglecting the presence of this mystery is actually knowing less well things.

The Kantian system of knowledge a posteriori, is twofold: sensibility, arrangement of the given, and, cognition, the logic in the arrangement of the given. The logic of the arrangement is determined….thought….. by the tripartite coordination of understanding, judgement and reason. — Mww

I see two unexplained assertions here: that there is a 'given' and that such a 'given' can be arranged. Now, it is one thing to say that we might not be able to know (with certainty) why these two assertions are true, another to say that speculating about these things is either meaningless or whatever. Honestly, I agree with the former but not the latter.

Such is the fate of metaphysics in general: a guy adds to a theory in some way, shape or form, then accuses the original of having missed what was added. It may just as well have been the case it wasn’t missed in the former at all, so much as rejected. So the new guy merely cancels that by which the original rejection found force, and from within which resides the ground of accusation of the missing. Even without considering your particular instance of this, it is found in Arthur’s critique of Kant, and, ironically enough, Kant’s critique of Hume, a.k.a., The Reluctant Rationalist. — Mww

I can hear you here, philosophy doesn't seem to 'progress'. However, I believe that is because philosophers sought certainty with their arguments. On the other hand, I believe that we can establish that some 'metaphysical theories' are more or less reasonable than others. Feel free to disagree.

Dunno about imperfect, but even if it is, it has nothing to do with being unconscious of some operational segment of our intelligence, in which no knowledge is forthcoming in the first place. Perhaps you’ve thought a reasonable work-around, but from my armchair, I must say if you agree with the former you have lost the ground for judging the relative quality of your own knowledge. — Mww

Our knowledge is imperfect in two ways: of many things we aren't conscious of and we can't have certain knowledge beyond the phenomena. But even if one disagrees with the previous phrase, in a more limited sense, it is imperfect in the sense that we do not know everything we can know.

Contingent, without a doubt. Imperfect? Ehhhhh……isn’t whatever knowledge there is at any given time, perfectly obtained? Otherwise, by what right is it knowledge at all? If every otherwise rational human in a given time knew lightning was the product of angry gods, what argument could there possibly be, in that same time, sufficient to falsify it? Wouldn’t that knowledge, at that time, be as perfect as it could be? — Mww

There is no need to 'invoke' ancient mythology. Even in science we made 'progress'. The Newtonian understanding of gravity is different from the understanding of the same phenomenon in General Relativity. The former theory has been 'falsified'. But I do not think that we can say that Newton was simply 'ignorant' of gravity because he didn't know General Relativity. There are degrees of (the quality of) knowledge. In fact, I believe that science itself shows us that our knowledge is limited, confuesed, imperfect etc even about 'phenomena'.

The system used to amend at some successive time the knowledge of one time, is precisely the same system used to obtain both. So maybe it isn’t the relative perfection of knowledge we should consider, but the relative quality of the system by which it is obtained. — Mww

In a sense, yes, I agree. But 'perfection' of knowledge is what is sought for. Plato and Aristotle famously said that philosophy begins in 'wonder' - we seek, we feel a need to improve the quality of knowledge.

Do you see the contradiction? What would you do about it? — Mww

IMO a good starting point is to differentiate between degrees of quality of knowledge, confidence about one's beliefs and so on.

More than a bit of a stretch I'd say, there would seem to be no way this could be possible. We see the same things at the same times and places, and since as far as we know our minds are not connected this is inexplicable in terms of just our minds. — Janus

Here you are assuming that space is mind-independent. There is no need to do that for a 'realist' IMO.

To make a crude analogy... think about the Matrix. Alice and Bob visit a city in the virtual reality of the Matrix. The buildings are not really there. When they compare their notes Alice and Bob find that a lot of agreement about the report of the city. Yet, there city is not 'really there'. But, their experiences, albeit deceptive, had been possible thanks to something external to them. So, there is no need to posit that the 'external reality' is 'like' the 'phenomenal world' we experience.

I don't see why we should assume that of the physical. The world shows lawlike patterns and regularities. I think the old image of dead, brute matter died a long time ago, but it still seems to live in some minds. — Janus

Ok. What are these laws and regularities in physical terms?

Today that sense is know as interoception―the sense of what is going on in our bodies. We also have proprioception―our sense of the spatial positions, orientations and movements of the body. — Janus

Not only that, however. When I, for instance, make a calculation I am not aware of any bodily processes. I am aware of a relation between concepts.

He says that there cannot be such existents, that they are neither existent nor non-existent. I think that is meaningless nonsense. — Janus

IMHO you (in the plural) are using 'existence' in a different way.
Let's take again the Matrix example, I wrote above. In a transactional way, the 'city' above is 'real'. Alice and Bob have to pay attention of 'what happens', there is interusbjective agreement in their reports and so on. However, the city's existence is merely virtual. 'Ultimately', there is no city. And 'the real world' 'outside' the Matrix can't be said to 'exist' in the same way the 'virtual world' exist.
Or, to make another example: think about dreams. If I dream about visiting a 'city', that 'city' might be said to exist in a sense - bumping into a wall might even give me painful sensations. However, it would be weird to denote with the same term 'existence' what is in the dream and what is 'in the waking world'.

So, is the 'mind-independent reality' more or less the same to the 'phenomenal world'? We do not a way of know. And we can't neglect the fact that our mind has an active role in shaping the 'phenomenal world'.

I'd say there is no certainty except in tautologies if anywhere. I agree our knowledge is imperfect, but it's all we have. — Janus

I almost agree with this. But I am open to the possibility of things like 'revelations', 'insights via meditative experiences' and so on that can allow us, in principle, to get a 'higher knowledge'. I do recognize that there are good reasons to be skeptical of these things, however.

I don't see the phenomenal world as a guess. If we were all just guessing then the fact that we see the same things in the same places and times would be inexplicable. Perhaps you mean our inferences about the nature of the phenomenal world? Even there, given the immense breadth and consistency of our scientific knowledge, I think 'guess' is too strong. — Janus

Well, pehaps 'guess' is a wrong word. Think about 'model' or 'map'. Just like a map is useful to understand a city. The map, however, doesn't necessarily give all that can be possibly known of the city. Nor, necessarily, the map is 'similar' to the city.
We might use the same map. But the fact that we use the same map doesn't imply that the city is like the map.
Note, however, that the map should share some structural similarities with the city. That's why I believe that the 'external reality' must be intelligible.

I think it is a kind of artificial problem. We experience a world of phenomena. It seems most plausible (to me at least) that the ways phenomena appear to us is consistent with the real structures of both the external phenomena and our own bodies. We can recognize that this cannot be the "whole picture" and also that, while our language is inherently dualistic, there is no reason to believe nature is dualistic, and this means our understanding if not our direct perceptual experience is somewhat out of kilter with what actually is. I think it is for this reason that aporia may always be found in anything we say. — Janus

Ok, I see. Not sure I agree, however. Think about the map in my previous paragraph.

We can, but experience on these and like forums tells me that people rarely change their opinion on account of debating about what seems most reasonable when it comes to metaphysical speculation. — Janus

:up: But even when we do not change our minds, discussion can help us to clarify our own positions. Changes in metaphysical positions also can require years.

I agree. I think a physicalism that allows for the semiotic or semantic dimension to be in some sense "built in" is the most reasonable. However many people seem to interpret the idea that mind in fundamental to entail and idealist position that claims mind as fundamental substance or as some form of panpsychism which entails that everything is to some degree conscious or at least capable of experience and some kind of "inner sense". I don't think it is plausible to think that anything without some kind of sensory organ can experience anything. — Janus

To me the problem with a 'physicalism that allows for the semiotic and semantic dimension' is a better position than a physicalism that doesn't and in which semiotics and semantics happen 'for no reason'. But IMO, I am not satisfied by this version of physicalism because the semiotic and semantic dimensions still seem to me a 'brute fact'. A fascinating 'brute fact', indeed, that can also be inspiring but still a brute fact.
Whereas, if one assumes that some kind of 'fundamental mental aspect' or 'Divine Mind' etc is fundamental, it's easier to understand why these properties are present even in matter.

Anyway we seem to agree on the major points. — Janus

Yes. And also we can have a fruitful conversation about our disagreements.

Which is your prerogative. My point was simply that the two views are distinct enough from each other that they should be considered as different theories altogether. — Mww

OK. IMO they share a lot in common, but you are right.

Of what there is no clue, is how the non-mental matter of appearance transitions to its mental component of intuition. That it is transitioned is necessary, so is given the name transcendental object, that which reason proposes to itself post hoc, in order for the system to maintain its speculative procedure. — Mww

Interesting. But isn't this a form of 'transcendental realism', though? I mean, if we can distinguish what in our experience is 'truly external' from us, it would be 'transcendental realism', right?

Even if there is a transcendental realist epistemological theory which explains Kant’s missing clue, it remains the case no human is ever conscious of all that which occurs between sensation and brain activation because of it, which just is Kant’s faculty of intuition whose object is phenomenon. — Mww

On this, I agree. That's why I think that our knowledge is imperfect. So, in a sense, we do not really know and Kant was right in saying that the mind has an active role. But denying knowledge of the external reality completely, I am not convinced of that.

Don't forget that the categories of the understanding and our sensory abilities are factors that we all share. They're not particular to individuals, although individuals 'instantiate' those capacities. I have just responded in the mind-created world discussion to further points along these lines. — Wayfarer

Yes, I agree. This might explain intersubjectivity. But IMO this is only part of the story. I believe that we are in good agreement that the 'phenomenal world' is not 'reality in itself'. It is an interpretation of it, our 'best guess', that is however the way we can know 'reality in itself'. Now, I do not claim any 'sure knowledge' about 'reality in itself', but I do think that, at least for the contents (not the form), of our 'phenomenal world' it is necessary to postulate it.
In a way, I agree with epistemic idealism that all 'views' about the 'noumenal' are speculative. But to me this is because we have imperfect congnitive faculties ('we see as through a glass'...) and we can't adequately know the 'external reality', which is nevertheless intelligible in principle. To me it seems the most reasonable hypothesis here.

Yes, and I would say that it can only explain the general forms that our experiences take, and not the commonality of experiences of particular forms (which we might call the content of experiences). — Janus

Well, if the structure of our cognitive faculties share a lot of properties, then the structure of pur experience is similar. But it is a bit of a stretch to say that all 'formal' properties of experience depend on the regulative faculties of our minds.

So, it is hard to say what we might mean by 'mind-dependent' in distinction to 'body/brain dependent'. — Janus

To be honest, I am not even sure that we can make a hard distinction between 'body' and 'mind'. I do not see them as different substances, although I admit that even from a phenomenological point of view we can distinguish mind and body*. To me the problem is trying to make sense of the mind in purely 'physical' terms, once you assume that the 'physical' is completely devoid of any quality that pertains to mind.

*Interestingly, in Buddhist scriptures you find the teaching of six senses. The first five senses are what we take as senses. But the sixth is the 'inner' sense of the mind. So, to a Buddhist when we are aware of a mental content, it's like being aware of a sense object.

That there are such existents is strongly suggested by science and even by everyday experience. Of course as soon as we perceive something it no longer strictly qualifies to be placed in that category. — Janus

I don't think that even Wayfarer reject that. However, the way things appear to us is conditioned by the cognitive faculties of our mind. Even our emotional states, biases and so on condition the way we process 'reality'. There is something external but we have a mediate knowledge of it and this knowledge in our case is imperfect. Can we be certain on how the 'external reality' is? I would say no, because our knowledge is limited and imperfect (and not strictly speaking becuase it is mediated). Note, however, that the epistemic idealist is right in suggesting that we do not have a direct knowledge of 'reality' and our 'phenomenal world' is our 'best guess' of it, so to speak (to borrow a phrase from St. Paul, 'we know as if through a glass, darkly'). Given that we do not have a possibility to 'check' how our 'interpretation of reality' corresponds to 'reality', we IMO should grant the epistemic idealist that we cannot make certain claims on the noumenal. The epistemic idealist might say that the 'noumenal' is beyond concepts, beyond intelligibility and we should be silent on it (and you find quite similar claims in some Buddhist and Hindu tradition, to be honest). I believe that it is a bit too far, even if partially correct, in a way. But, again, in a way everything we assert without an 'infallible guarantee' on the validity of our statements about the 'noumena' ('external reality') is in a way pure speculation. We can, however, debate on which picture of the 'noumenal' seems more reasonable.

I agree with most of what you say here, although I'm not clear on how you have related it to theism. In Kant was the problem that the senses might thought to be deceptive veils, and I think Hegel effectively dealt with that error in his Phenomenology. — Janus

Ok, but note what I said in the previous paragraph. I address the point about theism later.

If we do away with the external world we are left with a mere Phenomenalism, which seems to explain nothing. By "external world" I simply refer to what lies outside the boundaries of our skins. I cannot see any reason to doubt the existence of external reality defined that way. What the ultimate nature of that external reality might be is unknown and perhaps unknowable. It might be ideas in the mind of god, or it might simply be a world of existents. — Janus

I think we agree on this!

You seem to allude to the idea that without god the intelligibility of the external world is inexplicable — Janus

Honestly, I can't make sense of intelligibility without mind. If physicalism were right, intelligibility of 'the world' seems to that has no explanation at all. Just a brute fact, that allowed our minds to navigate in the world. Note, however, that mathematical and logical laws (the 'laws of reasons' in general) seem to have a character of 'eternality' (or 'time independence') and 'necessity', which both do not seem to be compatible with a view that mind isn't in some sense fundamental. Now, of course our minds can't be fundamental - we are born, we grow, we die etc. But the 'laws of reason' seem to be irreducible. And, in fact, if you try to explain them as derivative to something else you have to assume them in the first place!

So, I am inclined to think that there is really a fundamental mental aspect of reality. Perhaps a 'Mind' that is the source of the intelligibility of everything. I acknowledge that this is a form of 'theism'. It seems to me that it is a more parsimonious explanation of intelligibility than considering it as an unexplicable 'happy' accident or 'brute fact'. Although, admittedly, I don't think that there are absolutely compelling arguments one can make on these things.

Yes, ofcourse. Interestingly, you can produce bombtester-like behavior in baths of fluid: e.g. — Apustimelogist

Interesting, will read!

For me, a mechanism like this is the most attractive explanation of quantum theory, something already postulated in the stochastic mechanical interpretation and some versions of Bohm. It sounds weird but it seems quite compatible with the ontologies of quantum field theory imo, which additionally also seems to tell us that there is no truly empty space, i.e. vacuum energy and fluctuations. — Apustimelogist

Perhaps. I know that there are some technical difficulties for de Broglie Bohm's extensions to QFT but I am not competent enough to comment.
I do not recall if I already shared with you this link about the Thermal interpretation of Arnold Neumaier. It is explicitly nonlocal, 'holistic' (in the sense that there are nonlocal properties of extended systems that can't be explained in terms of local properties) and the author claims that it is Lorentz invariant and can explain also QFT.

The main non-classical feature seems to be the presence of those nonlocal fundamental properties.

A classical analogy for interaction free measurements, as in the quantum Zeno Elitzur–Vaidman_bomb_tester, can be given in terms of my impulsive niece making T tours of a shopping mall in order to decide what she'd like me to buy her for her birthday.
... — sime

Ok, but IMO the classical analogy you propose misses the fact that the there is a change in the 'state' of the system by not detecting it. This is quite bizzarre from a classical viewpoint.

Of course, you can interpret the 'state' of the system as 'what we know' (or even 'what we believe') of the system. However, this isn't exactly like the classical case because there are no hidden variables in the epistemic interpretation of QM

OR you say that the 'state' is in some way real. But if that is the case, then, you have to introduce some kind of nonlocality or some other 'weirdness' like MWI.

Sorry for the delay! Been busy!

I made the same point myself earlier in the thread but it received no response―which is probably understandable. — Janus

For me the problem with this 'variant' of Kantianism is that it can only explain the form of appearances, not that there are appearances at all. If Kant's 'idealism' asserted that appearances are mere mental contents then, it would be subjective idealism. However, Kant also asserts that there is 'something' about phenomena that it is not 'mental'. However, we are left with no clue on how that 'something' is related to appearances.

I do believe that the great merit of Kant (and epistemic idealism in general) is his view that mind isn't a 'passive' recorder of 'what happens' but that it actively interprets phenomena. I also believe that we can't easily differentiate what is 'mind-dependent' from what is 'mind-independent', an antinomy if you will.

Anti-realists, anti-materialists, anti-physicalists have a vested interest in denying the reality of things in themselves, because to allow them would be to admit that consciousness is not fundamental, and, very often it seems, for religious or spiritual reasons they want to believe that consciousness is fundamental, especially if they don't want to accept the Abrahamic god. One can, without inconsistency, accept the Abrahamic god and be a realist about mind-independent existents. — Janus

Well, I am sympathetic to theism, in fact. IMO, our mind can 'produce' the representation because the 'external reality' is itself intelligible. However, we can only know it by interacting with it and producing a representation of it, which is the 'phenomenal world'. It's not a 'deceptive' veil - at least, if we remember that it is also the result of the interpreteation that our mind makes of the 'external reality'. In fact, I think that the act of 'knowing' is always mediated. The 'external reality' is the 'known', our mind is the 'knower' and the 'phenomenal world' (or the 'representation') is the medium by which our mind can know the external reality. Such a knowledge, however, is imperfect and this is why we make mistakes. To make an analogy, when I read your post, I (the knower) imperfectly know your thoughts (the 'known') via the written texts I read and my own previous knowledge about the English language, what I have studied in philosophy etc (the medium).

Note, however, that I am positing that the 'external reality' itself is intelligible. And as I said elsewhere, I don't think that physicalism alone can explain that intelligibility. Its presence suggests to me that there is at least a 'fundamental mental aspect' of reality, which isn't my mind, our mind, or the 'human mind' in general.

Better to say D’Espagnat developed a more complete epistemic idealist theory grounded in transcendental realism, than to say Kant developed a less complete epistemic theory because it wasn’t. — Mww

Not sure what is your point here. I meant that I prefer d'Espagnat's view than Kant's because I find the latter's view lacking in a way the former's view isn't. So, yeah, d'Espagnat's view perhaps is better described as a (subtle) form of 'transcendental realism'. But despite preferring the view of d'Espagnat I think that Kant's has its merits.

But "interaction-free measurements" work because there is a physical change in the system behavior due to a change in the experimental context, analogous to closing a slit in the double slit experiment. — Apustimelogist

Agreed with that. But this doesn't change the fact that it seems quite different from the classical case. In fact, I believe that your example is perfect here. In de Broglie-Bohm, changing the experimental context has a nonlocal effect also on the measured system. In this, it is quite similar to Copenaghen. Bohm himself acknowledged that Bohr with his 'indivisiblity of the quantum of action' was quite close to his view. Of course, according to Bohm, Bohr's model was incomplete but not 'completely wrong'.

But where is the particle? Since the wave is uniformly spread throughout space, there is no way for us to say that the electron is here or there. When measured, it literally could be found anywhere. So while we know precisely how fast the particle is moving, there is huge uncertainty about its position. And as you see, this conclusion does not depend on our disturbing the particle. We never touched it — Brian Greene, The Fabric of the Cosmos

There are also Interaction-free measurement, which IIRC do not seem to require a direct interaction between the system and the measurement apparatus and yet they do bring an 'update' to the wavefunction.

To make an example: if you emit a particle and a detector detects it, you have a normal measurement, which involves an interaction, and you now know the position of the particle. If you, however, activate the detector and it doesn't detect the particle, you know where the particle is not. This suggests that you was able to 'update' the wavefunction of the particle in question without interacting with it.

If I am not mistaken, in de Broglie-Bohm's view, this involves some kind of nonlocal interaction between the detector and the particle. A QBist would say that no interaction occurred and the 'negative result' update our 'degree of belief' of where the particle is.

In any case, the so called 'interaction-free measurements' are ways to get new information without getting 'positive' results.

So again this lends support to some basic aspects of Kant's (as distinct from Berkeley's) form of idealism. The idea that 'the structure of possible experience constrains what can count as empirical knowledge' has had considerable consequences in many schools of thought beyond quantum mechanics. As for Berkeley, though, these kinds of developments provide a partial vindication - by bringing the observer back to the act of observation ;-) — Wayfarer

Thanks for the Bitbol reminder! In any case, as I said, I believe the great merit of epistemic idealism (of whatever form) is to remind us that the mind has an active role in give an 'order' to what we are experiencing. In other words, we can't neglect the role that the 'constraints of possible experiences' have on what we actually experience.

Still, I honestly think that epistemic idealists (like Bitbol, Kant etc) do go too far.

For instance, in order to avoid to imply that we create the 'empirical world' out of pure thought, Kant had to concede that there is a reality beyond of experience that provide our mind the 'matter', to use Arisostotelian language, for then 'building up' the 'forms' via the faculties of sensibility, intellect and so on. However, it seems to me that if the 'reality beyond/before phenomena' was structureless, it would not possible for us to give it a 'form'.

Personally, I think that D'Espagnat provides a good correction of epistemic idealism. The active role of mind is accepted almost to the degree of Kant etc but, at the same time, D'Espagnat's view accepts that the 'reality beyond/before phenomena' has its own structure that is 'veiled' for us (and by studiying the 'empirical world' we can know 'as through a glass darkly' to borrow again, out of context, St. Paul's famous phrase).

So, yeah, I guess that for me Kant's and Bitbol's approach is incomplete rather than being 'misguided', so to speak.

This is where his nominalism shows through. By designating universals purely mental or linguistic, Berkeley undercuts the possibility of a robust theory of lawlike regularities within his immaterialism. — Wayfarer

Yeah, I agree. That's one of his weak points. But I would also say that his 'immaterialism' by no means implies nominalism. In fact, I would even say that - at least for certain concepts (e.g. mathematics) - Berkeley's own system would actually make more sense with a 'realism about universalism' - as concepts present eternally in the mind of God.

Kant does acknowledge that there is a domain beyond our knowledge - so there is a reality beyond, or in a sense other than how it appears to us. But he avoided the weakness in Berkeley's argument by allowing that the forms of thought (categories) and of intuition are universal structures of cognition, not mere names — though still mind-dependent in his transcendental sense. — Wayfarer

The problem is that in order for our own categories and intuition to 'ordain' the empirical world, I believe you need to posit some structure onto the noumenal and this suggests that we do have some knowledge of the noumenal, i.e. one ends up to a form of 'indirect realism' or something like d'Espagnat's view.

//also consider that the ‘material substratum’ is nowadays regarded as being of the nature of fields in which particles are ‘excitations’. I think this is why Berkelian idealism keeps being mentioned in this context.// — Wayfarer

Well, 'excitations' could not be 'ideas', however. On the other hand, contemporary physics tells us that physical reality is quite different from what it seems to us at the most fundamental level anyway.

Berkeley, by contrast, accepts that there are regular sequences among ideas (what we might call “natural causes”), which God has ordained as the stable framework of experience. These patterns aren’t illusions; they’re effective causes in the world as God presents it to us. — Wayfarer

One might ask, however, how one that endorses an 'idealist' position that flatly denies the existence of some kind of material substratum can explain the regularites (and 'intersubjective agreement') without assuming the existence of God or some God-like being. Of course a theist would not have much problems but a non-theist would perhaps see this as a problem of idealism.
For instance, I always found Kant's arguments to explain intersubjectivity and regularities without appealing to some 'reality beyond phenomena' as insufficient. Of course, Kant posited some kind of unknowable reality beyond phenomena. But still IMO Berkeley at least gives an account on how we might explain the 'order' of phenomena.

This is why I think in another context he could have been something like a logical positivist. — Apustimelogist

It is not surprising IMO. Logical positivists actually are the result of a tradition that goes back to the Empiricists in the Enlightenment, especially David Hume. But Hume was inspired by Berkeley and Locke before him. Then, of course, we have the 19th century positivists like Mach and, finally, the logical positivists.

But note that empiricists, idealists and positivists till the 19th centuries were inspirations of many physicists in the 20th century who weren't logical positivists. These include the 'fathers' of QM but also someone like Einstein.

The OP mentioned that 'idealism' has been influential and a source of inspiration for recent scientific discoveries (even when criticized). I would say that on this point the OP isn't wrong.

But specifically for Berkeley, as an Immaterialist, he does not believe in a world of material substance, fundamental particles and forces, but he does believe in a world of physical form, bundles of ideas in the mind of God. — RussellA

I agree! I would add that then those ideas are also present in the minds of humans (and other created spirits) when the latter percieve the former. And God is the one who assures that our minds perceive the correct of those ideas at the proper times.

In many contexts physical and material are synonyms. Asserting that a mental content is 'physical' can be potentially misleading. I do understand why the SEP article does that but it is according to Berkeley everything is either minds or mental contents. I doubt that, say, also many physicalists would accept to call 'physical' something which is a mental content.

Yes, I agree that Berkeley's target were secular materialists of his day.
But IMO he used the empiricists' arguments (e.g. Locke) to show that phenomena are entirely mental and an external substratum was unnecessary.

However, it is quite different from what traditional theism says on matter. In that system we are acquinted with some features of the physical world. It is a type of direct (yet not naive) realism from our perspective. Of course, given that theism posits that everything is created by God, ultimately it is all ontologically dependent on the Mind of God.

Berkeley IMO took away the 'physical' using empiricist arguments. But in doing so he pointed to God as an explanation why there is intersubjective agreement, regularities in phenomena and so on.
IIRC, he also criticized other theists because, according to him, positing an external material substratum for phenomena 'weakens' so to speak God's role.

The problem is always that ‘mind’ is outside a Wheeler’s usual term of reference. But Andrei Linde doesn’t hesitate to speak about it. — Wayfarer

Agreed. Wheeler, Bohr, Dirac etc were all ambiguos. One feels like they didn't want to assign mind a role but it is not too difficult to see it as an implicit conclusion of their reasoning.

Others like Linde, the QBists etc are not. IIRC, even John von Neumann wrote that the 'self' was responsible for collapse.

QM itself is basically silent. You are free to consider whatever you want to be an observer IMO. But the formalism does suggest that while you can apply QM to anything, you can't describe everything at the same time quantum mechanically - something must be described classically (I believe some physicist made a famous quote that says this).

But I don’t think that the corollary of that is that non-perceived objects cease to exist. They exist in the sight of God — Wayfarer

IMO it is more like God 'sends' to our minds (spirits) the right phenomena (mental contents) we have to percieve in a given time.

I have always asked myself how Berkeley's position fits (if it does) with traditional theistic metaphysics. Maybe some resident expert of that traditional view could explain this but I can't. To me Berkeley's view is something like traditional theism minus the physical world (which becomes entitely mental contents) but I am not sure. But I read about him many years ago.

When one begins to say that 'measurement' is not a name for 'any physical interaction' (like RQM for instance does) but to mean something more complex, yeah it is not a stretch to think that 'mind' has some role.

I do believe for instance that Wheeler's view implies (perhaps unintentionally) a role of the 'mind'.

John Wheeler, 'Law without Law' — Wayfarer

IIRC John Wheeler is a good example of how sometimes physicists themselves provide writings that can be difficult exercises of exegesis, so to speak.

In the extract you quoted, for instance, Wheeler equates the terms 'registered' and 'observed' and this suggests that, according to him, mind is not necessary to 'collapse' the quantum statee. A registering device perhaps is also able to do that.

Two comments here:

(i) one can also say that the content of these 'recordings' become menaingful only when a mind gets to know them. If this is true, one would say that perhaps Wheeler's position implies idealism. Also, registering devices are human made so the activity of the mind actually might be considered a precondition for uniderstanding of their recordings.

(ii) even if (i) is wrong, however, the 'hard realist' objection of John Bell in his Against Measurement:

It would seem that the theory is exclusively concerned about ‘results of measurement’, and has nothing to say about anything else. What exactly qualifies some physical systems to play the role of ‘measurer’? Was the wavefunction of the world waiting to jump for thousands of millions of years until a single-celled living creature appeared? Or did it have to wait a little longer, for some better qualified system . . . with a PhD? If the theory is to apply to anything but highly idealised laboratory operations, are we not obliged to admit that more or less ‘measurement-like’ processes are going on more or less all the time, more or less everywhere? Do we not have jumping then all the time?

actually doesn't fare better if, instead of living or conscious beings, registering devices are those needed to collapse. In fact, it would be still quite strange that a complex inanimate physical object is necessary for the collapse. The world would still have 'waited' a lot to 'collapse'. If the world still had to wait in this case, why not waiting a bit more?

So, those views according to which a real collapse (not just 'decoherence') happens when some complex physical objects do not seem truly better for scientific realists than those which involve some kind of 'mind' (and as I said elsewhere, generally nowadays those who do say that mind has a role in collpase generally interpret collapse in a purely epistemic way, just as an update of knowledge/degree of belief and not that the mind has a 'causal effect' on a real object called 'wavefunction').

Kant doesn’t say our faculties impose order on “reality in itself” — only on the raw manifold of intuition as it is given to us. The in-itself is the source of that, but its true nature remains unknowable; what we know is the ordered phenomenal field that results from the mind’s structuring of the manifold of sensory impressions in accordance with its a priori forms and concepts. — Wayfarer

The problem is if you claim that the reality beyond/prior to phenomena is completely unknowable you have either to accept (i) that the activity of the mind in ordering experience is enough to explain the order we see in phenomena or (ii) that (i) is false and you can't explain how the order we see arises. (ii) would be a form of skepticism. Both are forms of transcendental/epistemic idealism but only in the first option you do have an explanation of the regularities we see.

I'm aware that D'Espagnat differed with both Kant and Berkeley, but he did mention both. Berkeley's idealism is often mentioned by physicists as representing a kind of idealism that they wish to differentiate themselves from. But the point is - he's mentioned! — Wayfarer

Yes, certainly Kant and Kantians did have an important role. They provided arguments that helped even those that, at the end, disagreed. As I said, I agree that also thanks to Kant and so on, we now are more aware about the interpretative role of the mind and we are more aware that 'what appears to us' might not be 'what is really there'.

What Berkeley objected to was the notion of an unknowable stuff underlying experience — an abstraction he believed served no explanatory purpose and in fact led to skepticism. His philosophy was intended as a corrective to this, affirming instead that the world is as it appears to us in experience — vivid, structured, and meaningful, but always in relation to a mind — although importantly for Berkeley, as a Christian Bishop, the mind of God served as a kind of universal guarantor of reality, as by Him all things were perceived, and so maintained in existence. — Wayfarer

Yes, according to Berkeley phenomena are mere appearances. There is nothing 'more' than 'what appears' to the mind. But notice that Berkeley explained things like (i) the intersubjective validity of empirical truths (e.g. scientific truths but not only that), (ii) persistence and stability of the 'world' (e.g. why, say, there aren't drastic changes of what we experience from a day to the following), (iii) the regularities of the 'world' (e.g. 'laws' of physics) and so on by appealing to God. God assures that we, both individually and collectively, have a consistent experience.

Kant, however, didn't want to explain any of the above by appealing to God. In fact, he said that it is the structure of our mental faculties that give us a structure, regulated etc phenomenal world becuase our minds condition appearances to have some characteristics. Since, however, appearances could not be generated completely by the subject, Kant still assumed that there is a non-phenomenal reality but it is unknowable. This unknowability is the reason why Kant isn't regarded as a 'realist' but as a 'transcendental idealist'.
The main problem with this, however, is that there is no sufficient evidence for us to claim that the stability, regularities etc can be wholly explained by the role that the mind has in 'ordanining' appearances. Same goes for intersubjectivity. It is not enough to say that we have 'similar minds' to wholly explain why the 'phenomenal world' appears similar to all of us. Furthermore, if the 'reality beyond/prior to phenomena' is unknowable, how could our cognitive faculties be able to 'order' appearances in the first place?

Notice that d'Espagnat disagreed with Kant here. In fact, he did believe that we can know, albeit partially and confusedly, the reality beyond phenomena (as 'through a glass darkly' to use a Biblical expression in a different context). Such a reality is veiled but not entirely inaccessible. Just like we can know in part and in a confused manner the features of a veiled statue by touching it, in the same way by studying phenomena, according to d'Espagnat, we can know the 'veiled reality'. So, while d'Espagnat's philosophy has many similarities to Kant's, they differ and, in fact, d'Espagnat's position is realist - a realism that, of course, share many things with transcendental idealism (and quite likely influenced by it) but still a realism (of a very paticular kind).

A similar thing is seen among cognitive scientists IMO. They recognize the ability of the mind to 'give a structure' to experience. The mind isn't a passive recorder of 'what happens' but an active interpreter. But IMO they do not go as far as Kant.
I agree, however, that transcendental/epistemic idealist philosophies did influece cognitive scientists (and not only them... undoubdetly they influeced also various physicists, especially starting from the 20th century). So, the importance of these philosophical approaches should not be understimated. In fact, I do believe that they can be (and had been) a source of inspiration for discoveries.


(Good OP btw)

You can see a pdf file of John Bell's article about 'local beables' here: https://cds.cern.ch/record/980036/files/197508125.pdf

No two experiences, whether NDEs or everyday perceptions, are ever exactly identical, even among people sharing the same event in the same moment. Even witnesses at a car accident: Their accounts vary based on vantage point, attention, emotions, and memory, yet the core facts often align. — Sam26

Yes, I agree. I was questioning if with NDEs we get the same degree of agreement that we can, confidently, assume that people witness the same 'experience'. But you are right, we can't expect to have perfect agreements between reports in any case.

This subjectivity is a hallmark of human consciousness, and it applies powerfully to NDEs. Research consistently shows that while NDEs share striking similarities (suggesting a possible universal mechanism), individual differences go beyond cultural backgrounds, influenced by personal psychology, expectations, neurobiology, and worldviews. — Sam26

Can all the differences in the actual experiences be explained by the differences among the subjects?

A 2024 Taylor & Francis review of NDEs across cultures and history found high similarity in features like out-of-body experiences (OBEs), encounters with light or beings, life reviews, and feelings of peace, appearing in approximately 60-80% of global reports. These similarities hold even when controlling for cultural expectations (e.g., Westerners might see Jesus, while Easterners describe Yama, but the "being of light" archetype persists). This is not unusual; it happens in our everyday experiences, too. — Sam26

Thanks for the reference, I'll try to check it.

To make an example to clarify my point... Let's say that Alice has a peaceful NDE where she has a life review, encounters some luminous spirits in a meadow which seems 'more real than real' and, then, encounters a 'supreme being of light'. The, Bob also reports a peaceful NDE where he gets the life review, encounters some spirits in a meadow that also he describes as 'more real than real' and, then, encounters a 'supreme being of light'. When, however, questioned further, Alice says that her review was also in the perspective of other people but this isn't true in the case of Bob. Also, let's say that you find out differences in the characteristics of the 'meadows' they 'saw'.

To me, even if we assume that they visited a 'realm' of sorts, they clearly had 'visited' different 'places'. It's not just that they identified the 'deity' according to their background but they had different experiences. So, I would not say that they are like two witnesses of a car accident or like two people that give an account of their journey to the same city (in the same time period).

Given these problems, can we consider the testimonies as reliable data to arrive, inductively, at some conclusions about, say, the presence or absence of an immortal soul, the characterstics of the afterlife and so on?

Note that I do not come from an 'a priori skepticism' or anything like that. But generally, I see an agreement about the themes (which of course might well be evidence of something important) but I have doubts that the 'harmonization' of these accounts gives a reliable 'theory' about 'how the afterlife looks like'.

Everett's thesis had to dumb-down the number of bases due to the finite but inexpressibly large actuality of the actual figure. — noAxioms

IMO not just for that reason, but also because he had to explain how 'classicality' arises.

Hence Rovelli saying that a thing cannot measure itself, it can only measure something sufficiently in the past to have collapsed into a coherent state. — noAxioms

Ok. I thought that he said that a thing can't measure itself becuase a thing can't interact with itself. Interesting.

'beable'. — noAxioms

The term 'beable' was introduced by John Bell as opposed to 'observable'. Basically, 'beable' were objects or properties that are definite (i.e. that can be represented mathematically with definite quantities) even if there is no measurement. Local realists, like Einstein, hoped to explain everything in terms of 'local beables' (like, say, point particles, local values of fields and so on) which interact with local interactions (i.e. interactions that aren't faster than light). Of course, what Bell proved is that you have either to assume that, ultimately, there are no 'beables' in the sense expressed above or that, ultimately, there are 'nonlocal beables' or at least beables that interact with faster than light interactions.

@Sam26, I also find NDEs fascinating and I am interested in your research.
Quick question... NDE reports show a remarkable convergence of 'themes' and descriptions among people of different cultures, life experiences and so on.
It seems to me, however, that there is no evidence that two NDEs can be exactly the same. That is, they can be very similar and this is quite interesting. But IMO from the accounts I have read, the reports show differences that can't be explained only by referring to their different cultural backgrounds. So, I would say this might raise skepticism for taking these reports literally as in the case of, say, two people that travel to the same city and then give you the account of that journey. A guess that my question is: do we have sufficient evidence that these experience give us 'faithful' descriptions of the same 'reality' and not dscriptions of similar yet ultimately different 'realities'? This doesn't seem to be a point that is addressed with sufficiently depth in other works on the topic I read.

Of course, this doesn't necessarily imply that NDEs are completely non-veridical and cannot serve as reliable testimonary evidences. Still, I wonder in your view how these subtle differences are to explained.

I don't understand any of that. There is no right/wrong basis under MWI. They all share the same ontology, but some are more probable than others, whatever that means. — noAxioms

No worries, as I myself said it is a quite secondary issue. Even if there is a counter-intuitive increase of number of 'bases' it is not a problem, I guess, for MWI-supporters as they already accept that there many more 'worlds' out there.

Thanks for the patience!

Ok, I see thanks for the clarification. To me, however, all this means that Nietzsche believed in some 'objective' morality of some sorts. If there are 'sick' and 'heal' ways in which the will can express itself and we can know this, it seems to me that an objective or at least 'inter-subjective' basis for ethics/morality (i.e. 'how to live'). This would mean that Nietzsche wasn't a relativist after all, despite what sometimes he claimed and what how some interpreters read him.

Also it is useful to remember that not all 'objective ethical theories' consider ethics as a purely extrinsic set of rules with no relation to our 'nature'. In fact, many of them regard 'ethical rules' as a way to 'heal' the will or to express the will in a 'healthy way'.

I think that many of Nietzsche criticisms apply to ethical systems where ethics is a purely extrinsic set of rules. It is questionable if they really apply to other ethical systems.

They are nowhere near sufficiently significant. I cannot think of a scenario, however trivial, where you'd see this. It would be the equivalent of measuring which slit the photon passed through, and still getting an interference patter. Interference comes from not knowing the state of the cat, ever. — noAxioms

Yeah, I was just wondering if their magnitude is small 'enough' after measurement/interaction. Some years ago, I read that there was some debate on this point.

Sure we do. You observe that by not measuring the spin, same as not measuring which slit. — noAxioms

I meant that the 'normal' basis is selected, after the measurement, due to the fact that our experimental apparatuses are structured in some ways. In other words, the reason why we observe things in the 'right' basis is that the the experimental apparatus has those properties it has. However, in principle, you could have that after the measurement the state vector 'collapses' to one of the vector in the 'wrong' basis.

But, again, it is perhaps an useless observation. No theory in physics, after all, explains why the world is structured in the way it is. So, MWI is perhaps also immune by this 'criticism'.

Well, sort of what you say about Schopenhauer.
By 'voluntarism', I mean a position that gives prominence to the will. So, for instance, the mere ability to excercise the will is 'freedom' in a voluntaristic system. I'll try to clarify what I meant by talking about the concept of freedom.

So, the mere ability to act in concordance with the will is what 'freedom'. Morality, according to Nietzsche, hinders that ability by constraining it with rules and this is why it is so bad. As I understand him, imposing on ourselves and others 'moral rules' suffocates disables the ability to act according to the will. Rather, Nietzsche would suggest, we should accept to live without putting constraints on the will and accept the suffering that such a way of life entails (due to, say, the conflict that inevitably happens).

This is clearly a different understanding on the ancient model of freedom (that you can find both in non-Christian and Christian philosophers of that time) according to which, in the case of rational beings, only a will that knows the 'good' is truly free and finds fulfillment. Nietzsche would say that such an understanding of freedom because all modes of willing, if they are not constrained by something else, are 'good'.

If this clarification didn't help, try to read my previous response ignoring the adjective 'voluntaristic'. I don't think that it is essential to understand what I wrote.

Why would you want interference removed? It is seen. Even a realist interpretation like DBB has the photon going through one slit and not the other, yet interference patterns result. We experience that. Perhaps we're talking past each other. — noAxioms

Yes, I think so. Probably it is because also I am muddlying the waters lol.

Anyway, my contention is that if the interference terms are too significant, in the Schrodinger's cat experiment, the version of the observers that sees the 'alive' cat should perceive in some ways the other 'world'. I get that decoherence explains that, due to the decoherence between the observer and the system you get definite outcomes but IMO one also needs that the interference terms become negligible to get the appearance of classicality (i.e. 'definitiness').

Hope I clarified a bit.

You don't know that, there being no evidence of it. Under MWI, there's no 'our', so every basis is experienced by whatever is entangled with that basis, with none preferred. — noAxioms

I disagree. In my example of spins, for instance, we observe either '+1/2' or '-1/2', but we never observe the state 1/sqrt(2)('+1/2'+'-1/2'). In other words, I am not sure how, in MWI, from 'first principles', without the assuming from the start that MWI must be consistent with our experience, we can derive the classical features that we observe.

Anyway, this is not an important point. I mean, perhaps it is asking too much.

Also, for the 'voluntaristic' part, I disagree but I admit that his voluntarism is quite strange as he questions the existence of the 'agents' that will or, as you say, see the agents as fragmentary.

In any case, he IMO was pretty clear that all geniune manifestations of 'life'/'will to power' were 'innocent', like an innocent play, and morality (whether religious, civil etc) was something that constrained the manifestion of that innocent play. Nietzsche was, of course, aware that in the world these 'plays' inevitably conflitct (both in the natural world and among humans). Conflict is inevitable but for Nietzsche this is not a bad thing. It is actually good (if it is not motivated by some kind of 'morality' or 'resentment' that constrains the will to power).

Clearly he was inspired by Heraclitus, e.g. (see here: https://en.wikisource.org/wiki/Fragments_of_Heraclitus ):

Time is a child playing draughts, the kingly power is a child's (fragment 52)

War is the father of all and the king of all; and some he has made gods and some men, some bond and some free. (fragment 53)

We must know that war is common to all and strife is justice, and that all things come into being and pass away (?) through strife. (fragment 80)

Already in 1873 in his unpublished work 'Philosophy in the Tragic Age of the Greeks' Nietzsche contrasted Heraclitus with Anaximander by saying that Anaximander thought that the conflict between extremes was an 'injustice' whereas Heraclitus viewed it as the expression of 'justice' (strife is justice).

Why I believe it is 'voluntaristic'? Because Nietzsche didn't distinguish between good ways in which life manifests itself and bad. Simply, whatever the will wills is good. The only bad thing is to hinder the manifestions of the will.