bunchberry

the study that found the universe is not locally real. Things only happen once they are observed

This is only true if you operate under a very specific and strict criterion of "realism" known as metaphysical realism. Einstein put forward a criterion of what he thought this philosophy implied for a physical theory, and his criterion is sometimes called scientific realism.

Metaphysical realism is a very complex philosophy. One of its premises is that there exists an "absolute" reality where all objects are made up of properties that are independent of perspective. Everything we perceive is wholly dependent upon perspective, so metaphysical realism claims that what we perceive is not "true" reality but sort of an illusion created by the brain. "True" reality is then treated as the absolute spacetime filled with particles captured in the mathematics of Newton's theory.

The reason it relies on this premise is because by assigning objects perspective invariant properties, then they can continue to exist even if no other object is interacting with them, or, more specifically, they continue to exist even if "no one is looking at them." For example, if you fire a cannonball from point A to point B, and you only observe it leaving point A and arriving at point B, Newtonian mechanics allows you to "track" its path between these two points even if you did not observe it.

The problem is that you cannot do this in quantum mechanics. If you fire a photon from point A to point B, the theory simply disallows you from unambiguously filling in the "gaps" between the two points. People then declare that "realism is dead," but this is a bit misleading because this is really only a problem for metaphysical/scientific realism. There are many other kinds of realism in literature.

For example, the philosopher Jocelyn Benoist's contextual realism argues that the exact opposite. The mathematical theory is not "true reality" but is instead a description of reality. A description of reality is not the same as reality. Would a description of the Eiffel Tower substitute actually seeing it in reality? Of course not, they're not the same. Contextual realism instead argues that what is real is not the mathematical description but is precisely what we perceive. The reason we perceive reality in a way that depends upon perspective is because reality is just relative (or "contextual"). There is no "absolute" reality but only a contextual reality and that contextual reality we perceive directly as it really is.

Thus for contextual realism, there is no issue with the fact that we cannot "track" things unambiguously, because it has no attachment to treating particles as if they persist as autonomous entities. It is perfectly fine with just treating it as if the particle hops from point A to point B according to some predictable laws and relative to the context in which the observer occupies. That is just how objective reality works. Observation isn't important, and indeed, not even measurement, because whatever you observe in the experimental setting is just what reality is like in that context. The only thing that "arises" is your identification.

Why did physicists start using the word "real" and "realism"? It's a philosophical term, not a physical one, and it leads to a lot of confusion. "Local" has a clear physical meaning, "realism" gets confusing. I have seen some papers that use "realism" in a way that has a clear physical definition, such as one I came across defined it in terms of a hidden variable theory. Yet, I also saw a paper coauthored by the great Anton Zeilinger that speaks of "local realism," but very explicitly uses "realism" with its philosophical meaning, that there is an objective reality independent of the observer, which to me it is absurd to pretend that physics in any way calls this into account.

If you read John Bell's original paper "On the Einstein Podolsky Rosen Paradox," he never once use the term "realism." The only time I have seen "real" used at all in this early discourse is in the original EPR paper, but this was merely a "criterion" (meaning a minimum but not sufficient condition) for what would constitute a theory that is a complete description of reality. Einstein/Podolsky/Rosen in no way presented this as a definition of "reality" or a kind of "realism."

Indeed, even using the term "realism" on its own is ambiguous, as there are many kinds of "realisms" in the literature. The phrase "local realism" on its own is bound to lead to confusion, and it does, because I pointed out, even in the published literature physicists do not always use "realism" consistently. If you are going to talk about "realism," you need to preface it to be clear what kind of realism you are specifically talking about.

If the reason physicists started to talk about "realism" is because they specifically are referring to something that includes the EPR criterion, then they should call it "EPR realism" or something like that. Just saying "realism" is so absurdly ridiculous it is almost as if they are intentionally trying to cause confusion. I don't really blame anyone who gets confused on this because like I said if you even read the literature there is not even consistent usage in the peer-reviewed papers.

The phrase "observer-dependence" is also very popular in the published literature. So, while I am not disagreeing with you that "observation" is just an interaction, this is actually a rather uncommon position known as relational quantum mechanics.

no that's dialectics 😏

A lot of people who present quantum mechanics to a laymen audience seem to intentionally present it to be as confusing as possible because they like the "mystery" behind it. Yet, it is also easy to present it in a trivially simple and boring way that is easy to understand.

Here, I will tell you a simple framework that is just 3 rules and if you keep them in mind then literally everything in quantum mechanics makes sense and follows quite simply.

1. Quantum mechanics is a probabilistic theory where, unlike classical probability theory, the probabilities of events can be complex-valued. For example, it is meaningful in quantum mechanics for an event to have something like a -70.7i% chance of occurring.
2. The physical interpretation of complex-valued probabilities is that the further the probability is from zero, the more likely it is. For example, an event with a -70.7i% probability of occurring is more likely than one with a 50% probability of occurring because it is further from zero. (You can convert quantum probabilities to classical just by computing their square magnitudes, which is known as the Born rule.)
3. If two events or more become statistically correlated with one another (this is known as "entanglement") the rules of quantum mechanics disallows you from assigning quantum probabilities to the individual systems taken separately. You can only assign the quantum probabilities to the two events or more taken together. (The only way to recover the individual probabilities is to do something called a partial trace to compute the reduced density matrix.)

If you keep those three principles in mind, then everything in quantum mechanics follows directly, every "paradox" is resolved, there is no confusion about anything.

For example, why is it that people say quantum mechanics is fundamentally random? Well, because if the universe is deterministic, then all outcomes have either a 0% or 100% probability, and all other probabilities are simply due to ignorance (what is called "epistemic"). Notice how 0% and 100% have no negative or imaginary terms. They thus could not give rise to quantum effects.

These quantum effects are interference effects. You see, if probabilities are only between 0% and 100% then they can only be cumulative. However, if they can be negative, then the probabilities of events can cancel each other out and you get no outcome at all. This is called destructive interference and is unique to quantum mechanics. Interference effects like this could not be observed in a deterministic universe because, in reality, no event could have a negative chance of occurring (because, again, in a deterministic universe, the only possible probabilities are 0% or 100%).

If we look at the double-slit experiment, people then ask why does the interference pattern seem to go away when you measure which path the photon took. Well, if you keep this in mind, it's simple. There's two reasons actually and it depends upon perspective.

If you are the person conducting the experiment, when you measure the photon, it's impossible to measure half a photon. It's either there or it's not, so 0% or 100%. You thus force it into a definite state, which again, these are deterministic probabilities (no negative or imaginary terms), and thus it loses its ability to interfere with itself.

Now, let's say you have an outside observer who doesn't see your measurement results. For him, it's still probabilistic since he has no idea which path it took. Yet, the whole point of a measuring device is to become statistically correlated with what you are measuring. So if we go to rule #3, the measuring device should be entangled with the particle, and so we cannot apply the quantum probabilities to the particle itself, but only to both the particle and measuring device taken together.

Hence, for the outside observer's perspective, only the particle and measuring device collectively could exhibit quantum interference. Yet, only the particle passes through the two slits on its own, without the measuring device. Thus, they too would predict it would not interfere with itself.

Just keep these three rules in mind and you basically "get" quantum mechanics. All the other fluff you hear is people attempting to make it sound more mystical than it actually is, such as by interpreting the probability distribution as a literal physical entity, or even going more bonkers and calling it a grand multiverse, and then debating over the nature of this entity they entirely made up.

It's literally just statistics with some slightly different rules.

I am saying that assigning ontological reality to something that is by definition beyond observation (not what we observe and not even possible to observe) is metaphysical. If we explain the experiment using what we observe then there is no confusing or contradiction, or any ambiguity at all. Indeed, quantum mechanics becomes rather mechanical and boring, all the supposed mysticism disappears.

It is quite the opposite that the statistical behavior of the electron is decoupled from the individual electron. The individual electron just behaves randomly in a way that we can only predict statistically and not absolutely. There is no interference pattern at all for a single electron, at least not in the double-slit experiment (the Mach–Zehnder interferometer is arguably a bit more interesting). The interference pattern observed in the double-slit experiment is a weakly emergent behavior of an ensemble of electrons. You need thousands of them to actually see it.

What is it then? If you say it's a wave, well, that wave is in Hilbert space which is infinitely dimensional, not in spacetime which is four dimensional, so what does it mean to say the wave is "going through" the slit if it doesn't exist in spacetime? Personally, I think all the confusion around QM stems from trying to objectify a probability distribution, which is what people do when they claim it turns into a literal wave.

To be honest, I think it's cheating. People are used to physics being continuous, but in quantum mechanics it is discrete. Schrodinger showed that if you take any operator and compute a derivative, you can "fill in the gaps" in between interactions, but this is just purely metaphysical. You never see these "in between" gaps. It's just a nice little mathematical trick and nothing more. Even Schrodinger later abandoned this idea and admitted that trying to fill in the gaps between interactions just leads to confusion in his book Nature and the Greeks and Science and Humanism.

What's even more problematic about this viewpoint is that Schrodinger's wave equation is a result of a very particular mathematical formalism. It is not actually needed to make correct predictions. Heisenberg had developed what is known as matrix mechanics whereby you evolve the observables themselves rather than the state vector. Every time there is an interaction, you apply a discrete change to the observables. You always get the right statistical predictions and yet you don't need the wave function at all.

The wave function is purely a result of a particular mathematical formalism and there is no reason to assign it ontological reality. Even then, if you have ever worked with quantum mechanics, it is quite apparent that the wave function is just a function for picking probability amplitudes from a state vector, and the state vector is merely a list of, well, probability amplitudes. Quantum mechanics is probabilistic so we assign things a list of probabilities. Treating a list of probabilities as if it has ontological existence doesn't even make any sense, and it baffles me that it is so popular for people to do so.

This is why Hilbert space is infinitely dimensional. If I have a single qubit, there are two possible outcomes, 0 and 1. If I have two qubits, there are four possible outcomes, 00, 01, 10, and 11. If I have three qubits, there are eight possible outcomes, 000, 001, 010, 011, 100, 101, 110, and 111. If I assigned a probability amplitude to each event occurring, then the degrees of freedom would grow exponentially as I include more qubits into my system. The number of degrees of freedom are unbounded.

This is exactly how Hilbert space works. Interpreting this as a physical infinitely dimensional space where waves really propagate through it just makes absolutely no sense!

I wouldn't take Chalmers' opinions on things that seriously. Chalmers is a metaphysical realist, a very dubious philosophical position, and thus all his positions are inherently circular.

Metaphysical realism presumes dualism from the get-go, that there is some fundamental gap between an unobservable "objective" reality beyond everything we can ever hope to perceive, and then everything we do perceive is some not real and a unique property associated with mammalian brains. To be not real suggests it is outside of reality, that it somehow transcends reality.

This was what Thomas Nagel argued in his famous paper "What is it like to be a Bat?" and then Chalmers merely cites this as the basis for saying the brain has a property that transcends reality, and then concludes if explaining the function of the brain (what he calls the "easy problem") is not enough to explain this transcendence, how is it that an entirely invisible reality gives rise to the reality we observe.

But the entire thing is circular, as there's no convincing justification the brain transcends reality in the first place, and you only run into this "hard problem" if you presume such a transcendence takes place. Bizarrely, idealists and dualists love to demand that people who are not convinced that this transcendental "consciousness" even exists have to solve the "hard problem" or idealism and dualism are proven. But it's literally the opposite: idealism and dualism (as well as metaphysical materialism) are entirely untenable positions until they solve the philosophical problem their position creates.

I am especially not going to be convinced that this transcendental consciousness even exists if, as Chalmers has shown, it leads to "hard" philosophical paradoxes. Metaphysical realists for some reason don't see their philosophy leading to a massive paradox as a reason for questioning its foundations, but then turn around and insist reality itself must be inherently paradoxical, that there really is a fundamental gap between mind and body. Chalmers himself is a self-described dualist.

It's from this basis that Chalmers says you cannot prove whether or not something is conscious, because for him consciousness is something transcendental that we can't concretely tie back to anything demonstrably real. It has no tangible definition, there are no set of obervables associated with it. If you have one transcendentally conscious person next to another non-transcendentally conscious person, Chalmers would say that there is simply no conceivable observation you could ever make to distinguish between the two.

Yet, if there are no conceivable ways to distinguish the two, then this transcendental property of "consciousness" is just not conceivable at all. It's a word without concrete meaning, a floating abstraction, and should not be taken particularly seriously. At least, not until Chalmers solves the hard problem of consciousness and proves his metaphysical realist worldview can be made internally consistent, only then will I take his philosophy as even worthy of consideration.

Quantum mechanics explains a range of phenomena that cannot be understood using the intuitions formed by everyday experience. Recall the Schrödinger’s cat thought experiment, in which a cat exists in a superposition of states, both dead and alive. In our daily lives there seems to be no such uncertainty—a cat is either dead or alive. But the equations of quantum mechanics tell us that at any moment the world is composed of many such coexisting states, a tension that has long troubled physicists.

No, this is a specific philosophical interpretation of quantum mechanics. It requires treating the wave function as a literal autonomous entity that actually describes the object. This is a philosophical choice and is not demanded by the theory itself.

The idea that two fundamental scientific mysteries—the origin of consciousness and the collapse of what is called the wave function in quantum mechanics—are related, triggered enormous excitement.

The "origin of consciousness" is not a "scientific mystery." Indeed, how the brain works is a scientific mystery, but "consciousness" is just something philosophers cooked up that apparently everything we perceive is an illusion (called "consciousness") created by the mammalian brain that is opposed to some "true reality" that is entirely invisible and beyond the veil of this illusion and has no possibility of ever being observed.

People like David Chalmers rightfully pointed out that if you believe this, then it seems like a mystery as to how this invisible "true reality" can "give rise to" the reality we actually experience and are immersed in every day. But these philosophers have simply failed to provide a compelling argument as to why the reality we perceive is an illusion created by the brain in the first place.

Chalmers doesn't even bother to justify it, he just cites Thomas Nagel who says that experience is "conscious" and "subjective" because true reality is absolute (point-of-view independent) and the reality we experience is relative (point-of-view dependent), and therefore it cannot be objective reality as it exists but must be a product of the mammalian brain. Yet, if the modern sciences has shown us anything, it is that reality is absolutely not absolute but is relative to its core.

Penrose's argument is even more bizarre, he claims that because we can believe things that cannot be mathematically proven, our brains can do things which are not computable, and thus there must be some relationship between the brain and the outcome of measurements in quantum mechanics in which no computation can predict them beforehand. Yet, it is just a bizarre argument. Humans can believe things that can't be proven because humans only operate on confidence levels. If you see enough examples to be reasonably confident the next will follow the same pattern, you can believe it. This is just called induction and nothing is preventing you from putting it into a computer.

According to Penrose, when this system collapses into either 0 or 1, a flicker of conscious experience is created, described by a single classical bit.

Penrose, like most philosophers never convincingly justifies that experience is "conscious".

However, per Penrose’s proposal, qubits participating in an entangled state share a conscious experience. When one of them assumes a definite state, we could use this to establish a communication channel capable of transmitting information faster than the speed of light, a violation of special relativity.

Here he completely goes off the rails and proposes something that goes against the scientific consensus for no clear reason. Why does his "theory" even need faster-than-light communication? How does proposing superluminal signaling help explain "consciousness"? All it does is make the theory trivially false since it cannot reproduce the predictions of experiments.

In our view, the entanglement of hundreds of qubits, if not thousands or more, is essential to adequately describe the phenomenal richness of any one subjective experience: the colors, motions, textures, smells, sounds, bodily sensations, emotions, thoughts, shards of memories and so on that constitute the feeling of life itself.

Now the author themselves is claiming experience is "subjective" yet does not justify it, like all sophists on this topic, they just always begin from the premise that we do not perceive reality as it is but some subjective illusion and rarely try to even justify it. That aside, they are also abusing terminology. Colors, motions, textures, smells, etc, these are not experiences but abstract categories. We can talk about the experience of the color red, but we can also talk about the experience of a rainbow, or an amusement park. Are amusement parks "subjective experiences"? No, it's an abstract category.

Abstract categories are normative constructs used to identify something within an experience, but are they not experiences themselves. You have an experience, and then you interpret that experience to be something. This process of interpretation and identification is not the same as the experience itself. Reality just is what it is. It is not blue or red, it is not a rainbow or an amusement park, it just is. These are socially constructed labels we apply to it.

Sophists love to demarcate the objects of "qualia," like red or green or whatever, as somehow "special" over any other category of objects, such as trees, rocks, rainbows, amusement parks, atoms, Higgs bosons, etc. Yet, they can never tell you why. They just insist they are special... somehow. All abstract categories are socially constructed norms used to identify aspects of reality. They are all shared concepts precisely because they are socially constructed: we are all taught to identify them in the same way. We are all shown something red and told "this is red." Two people may be physically different and thus this "red" has different impacts on them, no matter how different it is, they both learn to associate their real experience with the same word, and thus it becomes shared.

This is true for everything. Red, dogs, trees, cats, atoms, etc. There is no demarcation between them.

In an article published in the open-access journal Entropy, we and our colleagues turned the Penrose hypothesis on its head, suggesting that an experience is created whenever a system goes into a quantum superposition rather than when it collapses. According to our proposal, any system entering a state with one or more entangled superimposed qubits will experience a moment of consciousness.

This is what passes for "science" these days. Metaphysical realism has really poisoned people's minds.

The definitiveness of any conscious experience naturally arises within the many-worlds interpretation of quantum mechanics.

Another piece of sophistry that originates from some physicists simply disliking the Born rule, declaring it mathematically ugly, so they try to invent some underlying story from which it can be derived that would be more mathematically beautiful. However, this underlying story is not derived from anything we can observe, so there is no possible way to agree upon what it even is. There are dozens of proposals and no way to choose between them. There simply is not "the" many-worlds interpretation. There is many many-worlds interpretations.

To make these esoteric ideas concrete, we propose three experiments that would increasingly shape our thinking on these matters.

All the experiments proposed deal with observing the behavior of living organisms, which is irrelevant to the topic at hand.

This is why many philosophers came to criticize metaphysical logic in the 1800s, viewing it as dealing with absolutes when reality does not actually exist in absolutes, stating that we need some other logical system which could deal with the "fuzziness" of reality more accurately. That was the origin of the notion of dialectical logic from philosophers like Hegel and Engels, which caught on with some popularity in the east but then was mostly forgotten in the west outside of some fringe sections of academia. Even long prior to Bell's theorem, the physicist Dmitry Blokhintsev, who adhered to this dialectical materialist mode of thought, wrote a whole book on quantum mechanics where the first part he discusses the need to abandon the false illusion of the rigidity and concreteness of reality and shows how this is an illusion even in the classical sciences where everything has uncertainty, all predictions eventually break down, nothing is never possible to actually fully separate something from its environment. These kinds of views heavily influenced the contemporary physicist Carlo Rovelli as well.

And as any modern physicist will tell you: most of reality is indeed invisible to us. Most of the universe is seemingly comprised of an unknown substance, and filled with an unknown energy.

How can we possibly know this unless it was made through an observation?

Most of the universe that we can see more directly follows rules that are unintuitive and uses processes we can’t see. Not only can’t we see them, our own physics tells is it is literally impossible to measure all of them consistently.

That's a hidden variable theory, presuming that systems really have all these values and we just can't measure them all consistently due to some sort of practical limitation but still believing that they're there. Hidden variable theories aren't compatible with the known laws of physics. The values of the observables which become indefinite simply cease to have existence at all, not that they are there but we can't observe them.

But subjective consciousness and qualia fit nowhere in our modern model of physics.

How so? What is "consciousness"? Why do you think objects of qualia are special over any other kind of object?

I don’t think it’s impossible to explain consciousness.

You haven't even established what it is you're trying to explain or why you think there is some difficulty to explain it.

We don’t even fully understand what the question is really asking. It sidesteps our current model of physics.

So, you don't even know what you're asking but you're sure that it's not compatible with the currently known laws of physics?

I don’t subscribe to Nagel’s belief that it is impossible to solve, but I do understand how the points he raises are legitimate points that illustrate how consciousness does not fit into our current scientific model of the universe.

But how?! You are just repeating the claim over and over again when the point of my comment is that the claim itself is not justified. You have not established why there is a "hard problem" at all but just continually repeat that there is.

If I had to choose anyone I’d say my thoughts on the subject are closest to Roger Penrose’s line of thinking, with a dash of David Chalmers.

Meaningless.

I think if anyone doesn’t see why consciousness is “hard” then there are two possibilities: 1) they haven’t understood the question and its scientific ramifications 2) they’re not conscious.

You literally do not understand the topic at hand based on your own words. Not only can you not actually explain why you think there is a "hard problem" at all, but you said yourself you don't even know what question you're asking with this problem. Turning around and then claiming everyone who doesn't agree with you is just some ignoramus who doesn't understand then is comically ridiculous, and also further implying people who don't agree with you may not even be conscious.

Seriously, that's just f'd up. What the hell is wrong with you? Maybe you are so convinced of this bizarre notion you can't even explain yourself because you dehumanize everyone who disagrees with you and never take into consideration other ideas.

This is accurate, yes. The cat in the box is conscious presumably, in my opinion of cats at least, but still can be “not an observer” from the POV of the scientist observing the experiment from outside the box.

"Consciousness" is not relevant here at all. You can write down the wave function of a system relative to a rock if you wanted, in a comparable way as writing down the velocity of a train from the "point of view" of a rock. It is coordinate. It has nothing to do with "consciousness." The cat would perceive a definite state of the system from its reference frame, but the person outside the box would not until they interact with it.

QM is about quite a lot more than coordinate systems

Obviously QM is not just coordinate systems. The coordinate nature of quantum mechanics, the relative nature of it, is merely a property of the theory and not the whole theory. But the rest of the theory does not have any relevance to "consciousness."

and in my opinion will make it look weird in retrospect once physics expands to a more coherent whole

The theory is fully coherent and internally consistent. It amazes me how many people choose to deny QM and always want to rush to change it. Your philosophy should be guided by the physical sciences, not the other way around. People see QM going against their basic intuitions and their first thought is it must be incomplete and needs to have additional complexity added to it to make it fit their intuitions, rather than just questioning that maybe their basic intuitions are wrong.

Your other comment was to a Wikipedia page which if you clicked the link on your own source it would've told you that the scientific consensus on that topic is that what you're presenting is a misinterpretation.

• https://en.m.wikipedia.org/wiki/Delayed-choice_quantum_eraser#Consensus:_no_retrocausality

A simple search on YouTube could've also brought up several videos explaining this to you.

• https://www.youtube.com/watch?v=s5yON4Gs3D0
• https://www.youtube.com/watch?v=RQv5CVELG3U

Edit: Placing my response here as an edit since I don't care to continue this conversation so I don't want to notify.

Yes, that was what I said. Er, well… QM, as I understand it, doesn’t have to do anything with shifting coordinate systems per se (and in fact is still incompatible with relativity). They’re just sort of similar in that they both have to define some point of view and make everything else in the model relative to it. I’m still not sure why you brought coordinate systems into it.

A point of view is just a colloquial term to refer to a coordinate system. They are not coordinate in the exact same way but they are both coordinate.

My point was that communication of state to the observer in the system, or not, causes a difference in the outcome. And that from the general intuitions that drive almost all of the rest of physics, that’s weird and sort of should be impossible.

No, it doesn't not, and you're never demonstrated that.

Sure. How is it when combined with macro-scale intuition about the way natural laws work, or with general relativity?

We have never observed quantum effects on the scale where gravitational effects would also be observable, so such a theory, if we proposed one, would not be based on empirical evidence.

This is very, very very much not what I am doing. What did I say that gave you the impression I was adding anything to it?

You literally said in your own words we need to take additional things into account we currently are not. You're now just doing a 180 and pretending you did not say what literally anyone can scroll up and see that you said.

I am not talking about anything about retrocausality here, except maybe accidentally.

Then you don't understand the experiment since the only reason it is considered interesting is because if you interpret it in certain ways it seems to imply retrocausality. Literally no one has ever treated it as anything more than that. You are just making up your own wild implications from the experiment.

I was emphasizing the second paragraph; “wave behavior can be restored by erasing or otherwise making permanently unavailable the ‘which path’ information.”

The behavior of the system physically changes when it undergoes a physical interaction. How surprising!

Both these figures are embarrassingly bad.

Hoffman confuses function for perception and constantly uses arguments demonstrating things can interpret reality incorrectly (which is purely a question of function) in order to argue they cannot perceive reality "as it is.," which is a huge non-sequitur. He keeps going around promoting his "theorem" which supposedly "proves" this yet if you read his book where he explains his theorem it is again clearly about function as his theorem only shows that limitations in cognitive and sensory capabilities can lead something to interpret reality incorrectly yet he draws a wild conclusion which he never justifies that this means they do not perceive reality "as it is" at all.

Kastrup is also just incredibly boring because he never reads books so he is convinced the only two philosophical schools in the universe are his personal idealism and metaphysical realism, which the latter he constantly incorrectly calls "materialism" when not all materialist schools of thought are even metaphysically realist. Unless you are yourself a metaphysical realist, nothing Kastrup has ever written is interesting at all, because he just pretends you don't exist.

Metaphysical realism is just a popular worldview in the west that most Laymen tend to naturally take on unwittingly. If you're a person who has ever read books in your life, then you'd quickly notice that attacking metaphysical realism doesn't get you to idealism, at best it gets you to metaphysical realism being not a coherent worldview... which that is the only thing I agree with Kastrup with.