Is it true that the moon does not exist if nobody is looking at it?

Quoting MTravers

This is what I would like to see discussed. Does the moon truly not exist if we do not observe it? What constitutes as evidence of existence and truth?

We were just discussing similar questions in another thread. My position - if the answer to a question is can not be determined, even in theory, it doesn't have a yes or no answer. It is a metaphysical question, a matter of preference and usefulness. It is very useful for us to assume that the world exists even when no one is watching.

Thank you for your reply. Okay, if the answer might be the truth about the existence of something cannot be determined as having a yes or no answer then that belief / assumption must be thoroughly examined to see if it is true. So the question is now why can't we prove or disprove the existence of the moon? In this case Bohr says that the existence of the moon cannot be determined. On what logic and, or evidence is he basing that assumption? I think that it is fairly easy to prove that the moon exists without directly observing it.

My concern now is if Bohr is correct all of science and the scientific method is called into question. If a single observation in time by multiple observers is not considered as evidence of existence then we have a problem. The problem happens whenever we don't do the experiment. If we choose to not continually observe the results of an experiment the second we stop the experiment, the experimental result becomes instantaneously meaningless. Whatever it is we were measuring returns to an unknown state as soon as we stop observing it. If we truly believe that is true the study of the Universe becomes pointless. I do agree with what you say as it is very useful and sensible that the world exists when we are not watching.

What is the Topic of this other discussion? I would love to observe that discussion

Quoting MTravers

I think that it is fairly easy to prove that the moon exists without directly observing it.

I interpret Bohr's comment not to refer to just seeing or other direct observation, but also indirect observation e.g. measuring the effect of the moons gravity on the oceans. If my understanding is not correct, then the question becomes trivial.

Quoting MTravers

So the question is now why can't we prove or disprove the existence of the moon?

Let's try this:

• Assumption - we cannot perceive the moon directly or indirectly.
• Definition of "prove" - Demonstrate the truth or existence of (something) by evidence or argument.
• Proposition - The existence of physical phenomena can not be proven without physical evidence, i.e. argument in the absence of evidence is not good enough.
• Definition of "evidence" - Facts or information indicating whether a belief or proposition is true or valid.
• Proposition - Physical facts and information are only obtainable by direct or indirect perception.

Reply to MTravers Einstein should have asked Bohr how he can prove atoms exist because no one had ever seen an atom. We infer their existence by the effects they have on the things we do see.

We can prove the moon's existence without looking at it by pointing to the tides. What causes the tides on Earth, if not the moon?

The strongest argument against this kind of claim, in my view, is what happens when you consider events which predate the advent of consciousness. This does two things:

(1) It reveals that there is a time in which all that is was unconditioned by the ideational imposition of 'form', or similar concepts; anything which produces a relativisation of space and time as such to perceptual space and time.
(2) It reveals that whatever our consciousness does, it dwells within this apparently unstructured universe radically indifferent to but nevertheless consistent with the advent of our consciousness.

More precisely, considering the universe prior to the advent of consciousness reveals a becoming which is not reducible to a becoming for a human. In the language of Locke, this is an affirmation of the difference between primary and secondary qualities - primary qualities are those which are not determined by their relationship to a person; like curvature, specific heat capacity, temperature, chronological age...

Levi Bryant articulates it (following Meillassoux) here:

By contrast, when we speak of primary qualities were are speaking of non-relational properties that are in the thing itself. These properties are non-relational in the sense that they do not depend on us in order to exist. As such, they are characterized as the “in-itself”. For Descartes these properties consisted of length, width, movement, depth, figure, and size. Meillassoux, by contrast, adopts the thesis that any aspects of an object that can be formulated in mathematical terms belong to the object in-itself.

this is not necessarily to affirm that properties such as temperature, distance, curvature are non-relational tout court, but they have their own specific strata of relations which cannot be seen as reducible to a relationship between them and a person. Such as temperature being a result of relations of motion of particles, curvature being generated from constitutive spatial (more generally, parametric) arrangements of an object.

I am okay with the following statements you make.

T Clark:Definition of "prove" - Demonstrate the truth or existence of (something) by evidence or argument.
Proposition - The existence of physical phenomena can not be proven without physical evidence, i.e. argument in the absence of evidence is not good enough.
Definition of "evidence" - Facts or information indicating whether a belief or proposition is true or valid.
Proposition - Physical facts and information are only obtainable by direct or indirect perception.

I don't I agree with the "Assumption- we cannot perceive the moon directly or indirectly" Maybe I am not understanding you. Please give an example. I am of the opinion that an individual can perceive the moon directly and indirectly.

I am also not sure if Bohr meant indirect observation as well. If I were forced to guess I would bet he was thinking in terms of Schrodinger's Cat as in making a direct observation as to whether the cat is alive or dead which cannot be done unless you make a direct observation That is why I used the word "directly".

Proof for the existence of the moon.
1. The moon's tides are an excellent indirect measurement that can be reliably made to confirm the existence of the moon. That was the first thing that came to mind.
2. I can use astronomical charts and computations to predict where in the sky the moon will be. I can then go outside and look up at the sky and confirm that the location of the moon matches the charts and computations. We can use mathematical models to predict the position of the moon.
3. We physically had astronauts land on the moon and take pictures of the earth from the moon. The astronauts photographed the moon as well. Millions of people all agree that evidence is real and valid.
4. The astronauts also brought back hard physical evidence in the form of moon rocks.

I see a lot of hard evidence that proves the existence of the moon. I believe that we recognize and perceive evidence of reality via our consciousness. So reality is not not defined by our consciousness it is only recognized using the tools of our senses and the mind. I cannot think of any evidence that supports Bohr's idea that the moon cannot be proved or disproved.

Quoting MTravers

I don't I agree with the "Assumption- we cannot perceive the moon directly or indirectly" Maybe I am not understanding you. Please give an example. I am of the opinion that an individual can perceive the moon directly and indirectly.

This is just my interpretation of what Bohr was saying. I was using it as the basic assumption so I could try to trace its consequences.

Quoting MTravers

I am also not sure if Bohr meant indirect observation as well. If I were forced to guess I would bet he was thinking in terms of Schrodinger's Cat as in making a direct observation as to whether the cat is alive or dead which cannot be done unless you make a direct observation That is why I used the word "directly".

As I said in my post, I interpret Bohr's statement to mean direct and indirect perception. If that isn't what he meant, the whole question dissolves and I agree with your position.

The only fact that we have is that experience exists. The proof for existence of other things outside and inside is difficult if not impossible.

Quoting MTravers

Albert Einstein is reported to have asked his fellow physicist and friend Niels Bohr, one of the founding fathers of quantum mechanics, whether he realistically believed that 'the moon does not exist if nobody is looking at it.' To this Bohr replied that however hard he (Einstein) may try, he would not be able to prove that it does, thus giving the entire riddle the status of a kind of an infallible conjecture—one that cannot be either proved or disproved.

This is what I would like to see discussed. Does the moon truly not exist if we do not observe it? What constitutes as evidence of existence and truth?

Is it an infallible conjecture? I agree there's a sense in which the relevant sort of conjecture is unverifiable and unfalsifiable. But to say a claim is unverifiable and unfalsifiable is not to say it's infallible.

I see no reason to suppose that a thing like the moon does not exist while we do not observe it. On the other hand, arguably there is at least one reason to suppose that a thing like the moon does exist while we do not observe it: because that supposition leads the way to the simplest account. For if there are lapses in its existence when it's not observed, we should want some account of how this happens to be the case, and it seems most reasonable to expect no definitive answer is forthcoming; whereas the contrary case leaves no such gap. By the simplest account, things in general are said to proceed the same way whether they are observed or not, excepting special cases.

Perhaps that has a metaphysical ring to it. We can address the question another way: Even if I'm not currently observing the moon, I have a pretty good idea where to find it, and what steps I might take to observe it from my current position. Any object that remains available to us in this way is said to "exist" even when it is unobserved. This is not a metaphysical thesis, but only a rule of use for the word "exist". Along these lines, we may remain agnostic on the metaphysical question, or even deny that it makes sense to ask such questions, while saying that the object continues to exist, to participate in the world, even while it is unobserved.

I had read that it wasn’t Neils Bohr that Einstein asked, but his friend Michael Besso on an afternoon stroll in the forests. It was asked with a tone of exasperation - like ‘surely you can’t believe that the moon doesn’t exist when nobody is looking at it!?!’ It is indeed true that Einstein and Bohr then went on to discuss such questions for decades afterwards, but the original question was asked of Besso (according to Walter Isaacson's biography of Einstein.)

The real question is: what obliged Einstein (of all people) to ask that question, at that point in history?
Einstein, as is well-known, was a physicist, not a philosopher, albeit a scientist with philosophical interests. But the point is, the question arose directly as a consequence of the work then being done on the nature of matter by Einstein, Bohr, Heisenberg, Pauli, and others (all of whom were brilliant scientists of the highest order.) Heisenberg, who was a younger contemporary of them (he made his major breakthroughs at an exceptionally young age) recounts that on various occasions he was brought to tears by the ferocity of the debate between the participants on the implications of quantum theory. Bohr, for his part, said 'that if you're not shocked by quantum physics, then you haven't understood it'.

And the reason for that, and for Einstein's question, was precisely because the discoveries of physics cast doubt on the notion that the objects of scientific analysis really existed independently of the act of observation. This is what is shocking, and what lead to Einstein's question. And the question still remains.

A realist would naturally assume that 'the atom', or whatever the fundamental unit of matter turned out to be, would exist regardless of it being observed or measured. But the implications of the uncertainty principle and 'the observer problem' were that in some sense, sub-atomic particles didn't really exist as a discrete unit, except for when they had been measured. For some reason, the very act of measurement had a causal effect on their ontological status. This is the well-known 'collapse of the wave function' effect which has been subject of dispute and conjecture ever since.

Some relevant essays, articles and books:

Quantum Mysticism: Gone but not Forgotten Juan Miguel Marin

Quantum weirdness: What we call 'reality' is just a state of mind Bernard D'Espagnat

The Mental Universe Richard Conn Henry

Quantum, Manji Kumar

And the debate is on-going.

One problem with citing Quantum Physics as a basis for philosophical speculation is that physicists are usually mediocre philosophers and philosophers are usually mediocre physicists.

Another problem is the often unacknowledged assumption that the microphysical is the only "fundamental" reality.

Well if one agrees with Einstein that objective reality is the way the Universe works and he is correct in his mind experiment concerning the moon. I think that many people if not most people would agree that in fact the moon does exist when it is not observed. So far we have only seen evidence that it exists whether we observe it or not.
The only way to prove that the moon really has the capability of suddenly not being there and drops out of existence when we stop looking at it is to see a sudden disappearance of its gravitational effect. That has never happened. The moon's gravity has always been there and has never vanished therefore the moon has always been there since its creation. The possibility that the moon would not be there simply based on its not being observed is not even a possible outcome.
If that turns out to be correct then Quantum Mechanics has a problem with its interpretation of how physical reality works. The moon even though it is a macroscopic object, is itself composed entirely of sub-atomic and atomic microscopic objects. Therefore if the moon is an element that exists independent of our observation then all the atomic objects inherit from this fact that they now have observable paths and velocities as a whole because the moon has an observable velocity and path. All of those un-observable microscopic objects are now elements of physical reality. That might be a bit of a stretch but I can't seem to find away to defeat Einstein's simple argument. It seems now that in reality even though the mathematics of QM works very well it can't really be relied upon to explain why or how things happen. This is becoming quite a conundrum.

I read somewhere - I forget where - that a research project had been commenced in the Stanford Physics Labs to try to answer this question once and for all. I can't remember the details, but I think it involved something to do with quantums and some very expensive measuring apparatus.

Until results are obtained from that or a similar project (there was mention of developing a network of international labs to work on it and share results, possibly involving the accelerator at CERN), we can only speculate.

Quoting andrewk

I read somewhere - I forget where - that a research project had been commenced in the Stanford Physics Labs to try to answer this question once and for all. I can't remember the details, but I think it involved something to do with quantums and some very expensive measuring apparatus.

Until results are obtained from that or a similar project (there was mention of developing a network of international labs to work on it and share results, possibly involving the accelerator at CERN), we can only speculate.

I believe there is a 74.95 possibility you are not serious. It would be higher except that philosophers are willing to consider almost any silly idea.

Anyone care to venture why Neils Bohr said ‘if you’re not shocked by quantum physics then you haven’t understood it?’?

(Note the two question marks. That is because it’s a question about a question, although that’s not important.)

Reply to MTravers We've already been doing this topic to death in another thread, but as a fresh encapsulation, I'd say: the most you can say is that the way the moon exists for you when you're looking at it doesn't exist when you're not looking at it, but the ways the moon exists for other things (its interaction with other parts of the world that are not-you) still carry on when you're not looking at it.

This is harping on my main theme of Externalism as being the proper solution to most of these sorts of problems related to consciousness. Consciousness is not the name of a process that goes on just in the head, in the skull, in the brain; it's the name of a process of interaction that actually bridges and connects things (actually physically, literally) and includes both of the interacting processes within itself.

It's a bit analogous to the roles we play in society - for my co-workers, I'm their boss, for my family I'm the father, for my wife her husband, for my friends a best mate, for my amateur sports team at the weekend, I'm a certain position in the team. In each of these presentations of myself to the world, the other aspects of my potential self-presentation are absent because they're not being presented to their respective receivers. (When I'm with my family, I'm not a teammate, etc.)

Similarly, being in general isn't a monovalent property, but a multivalent property. The aspect a thing has for me, it has only because the interposition of my brain and sensory apparatus at that time and place, affords an opportunity for the thing to manifest a "side" of itself that it could never have manifested without that opportunity - and likewise, it presents me with an opportunity to manifest a new, hitherto-dormant (or hitherto-merely-possible) side of myself to it.

Again, going back to the interpersonal level, that's one reason why we value relationships - because being with different people draws different aspects of ourselves out of us, it actually gives us more opportunities to manifest aspects of our own existence. (And often that reflects back into self-consciousness - for example, it's common for a musician to play their track to a friend, and hear it in a different way "through his ears," so to speak.)

Reply to gurugeorge :up:

Reply to Wayfarer

Actually, your quote is generally attributed to The Philosophical Writings of Niels Bohr, David Mermin, notes that when reviewing the three volumes of The Philosophical Writings of Niels Bohr, he couldn't find any mention of it.

Other things Niels Bohr is reputed to have said;

It is wrong to think that the task of physics is to find out how Nature is. Physics concerns what we say about Nature.

Isolated material particles are abstractions, their properties being definable and observable only through their interaction with other systems.

So, in answer to your question, he probably didn't say anything of the sort, and if he did, it's unlikely that he meant that any brand of mystical woo is now on an equal footing to science.

Reply to MTravers That Einstein quip about the Moon should not be taken too literally (or at all literally). Its context is a scientific debate about quantum physics, which is wide-ranging and in large part philosophical in its own right, but since this is a metaphysics & epitemology section and your line of questioning doesn't seem to engage with that specific debate, we can leave it aside. Suffice it to say that in the context of the historical debate, indirect observation most definitely counts as an observation. If you can observe indirect effects of the Moon, that means that its wavefunction has long since "collapsed" (to use Bohr's preferred interpretation), so the question is moot.

Quoting MTravers

Does the moon truly not exist if we do not observe it? What constitutes as evidence of existence and truth?

That suggests that the moon does exist, if we are observing it.

But the way in which things exist when we are observing them involves us, the nature of our senses. For example, that I see the moon as a certain colour is a function of my eyes and my brain, not the moon in itself.

So, if I am not looking at the moon, it certainly does not exist, not in the same way it does when I am looking at it.

Quoting gurugeorge

Similarly, being in general isn't a monovalent property, but a multivalent property. The aspect a thing has for me, it has only because the interposition of my brain and sensory apparatus at that time and place, affords an opportunity for the thing to manifest a "side" of itself that it could never have manifested without that opportunity - and likewise, it presents me with an opportunity to manifest a new, hitherto-dormant (or hitherto-merely-possible) side of myself to it.

Perhaps the Moon is the manifestation rather than the external thing(s). I'm not particularly keen on reductionism, which I think is unavoidable otherwise. When I talk about the Moon (or apples, or cats), am I really just talking about a particular mass of particles? There's more to it than that.

Quoting Michael

When I talk about the Moon (or apples, or cats), am I really just talking about a particular mass of particles? There's more to it than that.

Surely what you refer to when you are talking about the moon changes depending on the context. If you were recounting a horror story about werewolves, then 'the moon' would refer to a frightening portent of danger, but when at your job at NASA, piloting the Apollo capsule, you are referring to the mass of particles (or more correctly the model of the physical world we currently share) because its the gravity from those particles that's going to guide the capsule.

I think this is the source of a lot of philosophical smoke and mirrors. Taking the ambiguities of one context and applying them to another.

Quoting Michael

Perhaps the Moon is the manifestation rather than the external thing(s)

Well the moon we experience is the only manifestation of anything we know, and it's external in the relevant sense of existing (in its other "faces" for other things) regardless of whether we're experiencing it or not.

I don't think there's any philosophical need for a split between manifestation and something hidden behind it. Philosophically speaking, we can coherently say that we experience what there is, because what we experience is the only place where our sense of "is" comes from, it's the meat and potatoes of existence so far as we're concerned.

Whether we get some revelation or news from afar of something other than what we experience, as we experience it, being all there is, and whether we believe that or not, is another story, but I don't think it's necessitated by any philosophical reflection, for example as a posit to make sense of what we experience.

Quoting gurugeorge

and it's external in the relevant sense of existing (in its other "faces" for other things) regardless of whether we're experiencing it or not.

That's the thing I'm questioning. If the Moon is the manifestation then it doesn't exist when we're not experiencing it, just as the character in a game I'm playing doesn't exist when it isn't being rendered. Of course, there's still something that continues to exist when not being experienced (or rendered), but that thing isn't the Moon (or the character).

So rather than say that the Moon exists which then appears to us a certain way, it's rather that some unspecified thing(s) exist(s) which then appears to us as the Moon. In terms of physics, there's no distinction between these two interpretations, but there is a conceptual difference, and I think my approach helps avoid naïve realism and, as I mentioned before, reductionism.

Reply to Michael I don't see why you can't just say it's the moon that exists.

The manifestation (the "face" it shows us) doesn't exist outside that interaction, but that doesn't mean you can't say that the manifestation is the moon - it is after all a manifestation of the moon, not some alien thing that's not-the-moon.

Going down this route would probably get us into mereology - re. what kinds of part/whole distinction are legitimate in this context. A leaf isn't a tree, but a leaf is tree, it's part of the tree-iness of the tree.

For example, suppose you see a leaf filling the screen in a movie, then the camera pans out, the leaf is part of a bunch, which are then revealed to be part of a tree. When one was looking at the leaf initially, was one looking at the tree? In one sense no, one was just looking at a leaf, but in another sense yes, one was looking at the tree, at one of its leaves.

I think we can treat objects in general in a similar way: the particular form of existence a thing has in interaction with us, you can say it's a distinct thing (like the leaf), but you can also say it's a manifestation of the thing (its being part of the whole tree, or in this case one of the object's possible ways of being, sc. its way of being for us).

Quoting MTravers

I am also not sure if Bohr meant indirect observation as well. If I were forced to guess I would bet he was thinking in terms of Schrodinger's Cat as in making a direct observation as to whether the cat is alive or dead which cannot be done unless you make a direct observation That is why I used the word "directly".

Why would it be an either/or with the cat being either dead or alive? Why would the "cat" not exist in an infinite number of states until we look at it? Why could it not change into a dog inside the box when we look at it?

There must be some universal determining factor that precedes our observations.

There are any number of related inquiries.

How might I prove to you that I'm self-aware?
Does it all cease to exist while I'm unconscious? Only to re-emerge when I come back to?
A blind person does not see the Moon; a synesthete might smell it.
A dead (or hypothetical) person cannot prove (or know) anything, let alone about the Moon.
If all else is (existentially) dependent on my experience thereof, then it all seem to part ways with ex nihilo nihil fit for example.
Can an unseen boulder falling off a cliff kill you?
Is phantom pain evidence of a real limb, or more, say, like a hallucination?
What's the deal with alien hand syndrome?

To me at least, it makes (significantly) more sense that I'm but part of a (significantly) larger world.

A lot of good concepts here. I would like to think about everything that was said and perhaps make an attempt at a solution to the dilemma. The solution will have to have in its explanation the mechanics of how the mind and consciousness function in the physical realm. In order to do this the origin of human consciousness will have to be included. This will require some discussion of spiritual components. Hopefully this is okay. Its a philosophical opinion. Testimonial evidence will be given to a limited extent. The goal is to get to the truth. I assume that for any problem there is always some answer. So the answer to whether the moon exists as independent object from our observation should have a definite answer. Either it does exist independent of our conscious observation or does not exist or some how both cases are true in some sort of duality solution.

What the Realist (Realist about a World independent of Mind) believes is that the existence of the moon is independent of the mind or of consciousness: if you took away all consciousness of the moon whatsoever, all perceiving of it, feeling it, seeing its effects, feeling its effects, thinking of it, dreaming of it, remembering it, believing in its existence—there’d still be a moon. This means he believes the following postulates:

• There is something other than Consciousness or Mind; Consciousness is one of (at least) two things; Consciousness is finite; there are (at least) two things.
• There is such a thing as the Unknown; there are two types of thing: the Known and the Unknown, Consciousness is not the only type of thing.
• Consciousness is not Reality itself; Consciousness is part of Reality; Consciousness is mere Appearance.
• There is a greater reality than Consciousness; there is something that is both Consciousness and the Unknown; there is an Objective.
• There is such a thing as a Whole is made up of Parts. (There is Consciousness and the Unknown and the whole of Reality).

(He need not however believe these postulates are exhaustive, or that this individuation of them is definitive.)

—And from these basic postulates, the Realist constructs his world.

There are many ways in which these postulates may be realised or visualised. The big ones, the original ones, are Space and Time. According to the spatial realisation, Consciousness is conceived as in certain places (where brains are)—and it is also conceived that there are other places, where they are not. According to the temporal realisation, Consciousness is conceived as when sentient beings are—and it is also conceived that there are other times, when they are not (earlier than them and later than them).

Realism is the basis for Science: Unknown and Known become, respectively, Physical World and Scientist.

(There are also deeper sceptical questions: Is there anything at all other than this experience, my experience? That is, not just, “Is there anything physical outside Consciousness?” but “Are there even two things? Is there even another consciousness?” And one deeper still: “Is there anything other than this experience I am having now?” —But these are outside the scope of this thread.)

I think the realist you are talking about has at a bare minimum just four metaphysical commitments:
1) that there are things that perceive
2) that there are things that are perceived
3) that there are perceptual relations between these things, i.e. relations we indicate with verbs like "to see", "to hear", "to touch" and so on.
4) neither of the types of things (1) or (2) depend for their existence on the fact that those relations sometime hold between them.

Empirical idealists, like Berkeley and perhaps Bohr - although I cannot be sure about him - deny (4) and claim instead that things that are perceived depend for their existence on being perceived. You can find his arguments for that conclusion in the first Dialogue Between Hylas and Philonous.

Where does this leave the moon when everyone's gone to sleep? Berkeley's answer was that God never sleeps, and perceives all things at all times.

The point in this question is not the Moon, but the word ËXIST".

If no one is looking at the Moon, the word ËXIST' has no meaning. Hence the Moon has no meaning either in that case.

Is it true that the moon does not exist if nobody is looking at it?
No.
Next!

Reply to charleton Not much of a philosophical argument. As for Corvus

If no one is looking at the Moon, the word ËXIST' has no meaning. Hence the Moon has no meaning either in that case.

, that's not much of an argument either, although at least it has a premise and a conclusion, even if it's not clear how they are related to each other. In any case, Corvus is right that the point isn't just about our moon, it's about existence in general, and whether things that are not actually being perceived exist or not. Occidental commonsense screams "of course they do", but what passes for commonsense in the West might not be true (I started another discussion on this point 'Commonsense versus physics').

Quoting jkg20

that's not much of an argument

An empty claim requires no argument.

You are misunderstanding what observation even meant. An observation can occur without any conscious or living being present. Basically, new-agers routinely misuse quantum mechanics to support all sorts of gibberish. For one thing, since Einstein came up with relativity, and even before then regarding transforms, we can't even say that we are "observing" the moon any more than we can say that the moon is "observing" us, since space is not absolute. That should give anyone a hint that the discussion was not talking about consciousness being necessary in order for a material world exist.

I only see the surface of the same side when I look at the moon, what are you guys looking at? I might as well ask if what's below the surface of the Earth actually exists because I don't look at it. Does my brain exist, heart, lungs, bones, etc? I've never witnessed a thought, even a philosophical one. For all these things I just mentioned, I see no better than the blind, who always seem to be omitted from this type of discussion. It's as if believing something doesn't exist because it can't be observed requires some faith....now there's a switch.

Let's just call the moon a cosmological constant.

> For all these things I just mentioned, I see no better than the blind

For some reason, vision is often abused in philosophy as the stand-in for all perception and observation. Thing is that vision works differently than smell, where you're inhaling pieces of the thing itself.

> I only see the surface of the same side when I look at the moon, what are you guys looking at? I might as well ask if what's below the surface of the Earth actually exists because I don't look at it. Does my brain exist, heart, lungs, bones, etc

Indirect observation has been brought up several times in this thread. The moon's gravitational influence continues when we're not looking at it, and our bodies do all the body-things like pumping blood, breathing and digesting (or having thoughts) while we're not looking inside.

I take that as evidence that a naive form of idealism is no more tenable than naive realism.

All this reminds me of the old (Oxford?) rhyme, which I recreate from momory:

'There was a young man who said, 'God,
Don't you find it exceedingly odd,
That that very large tree
Simply ceases to be
When there's no-one around in the Quod?'

To which, quite relaxedly, God
Said 'Nothing about it is odd,
And that very large tree
Never ceases to be -
I am always around in the Quod'.

Sorry about spelling and punctuation above - as a trained typist and an old English teacher I sufferwith this keyboard!

God in the Quad by Ronald Knox ( Balliol Oxford)

There was a young man who said "God
Must find it exceedingly odd
To think that the tree
Should continue to be
When there's no one about in the quad."

Reply:
"Dear Sir: Your astonishment's odd;
I am always about in the quad.
And that's why the tree
Will continue to be
Since observed by, Yours faithfully, God."

This is the version I am familiar with. The sentiment is the same and Knox captures well Berkeley's concern, unsurprising as a theologian to have a role for God in the sustaining of the Universe. An earlier contributor is quite right to bring in quantum mechanics where the issue of non measurement comes to the fore as having an influence on events.

Quoting Edmund

o have a role for God in the sustaining of the Universe. An earlier contributor is quite right to bring in quantum mechanics where the issue of non measurement comes to the fore as having an influence on events.

Can a supernatural being perform a measurement? Is God collapsing the universal wave function to this universe, allowing us to evolve?

Reply to Marchesk Quantum mechanics is at best irrelevant to the idealism v materialism debate, and at worse just invites obscurantism and confusion. A materialist interpretation of quantum mechanics is possible, as is an idealist one. Einstein's question apparently was addressed to those early QM theorists who leaned towards an idealist interpretation, but interpretations of QM have moved on since the days when the so-called "Copenhagen" and "Hidden Variable" interpretations were the only games in town.

I think the kind of idealism that Berkeley propounded is best argued for by investigating the basic metaphysical assumptions behind the relational view of perception - @jkg20's post earlier in this discussion pinpoints the basic assumptions, but to develop a full blown argument out of them takes a lot of time (believe me, I've tried) and involves dealing with issues concerning nominalism v realism about properties , personal identity over time, adverbialism and representationalsim in the philosophy of mind, to name just a few. Whether you can have Berkelian idealism without also requiring God to be around in the quad is an interesting question.

If nobody ever observed the Moon, then there'd be no proof it exists. Either the moon exists or it doesn't. Without proof, you'd be unable to prove it's existence or nonexistence. The existence of the Moon would be unknown. Things need scientific evidence to be proven, while people's beliefs aren't always accurate. For example, when I feel confident I got 100% on a test, but I actually gave some incorrect answers.

Reply to MetaphysicsNow

Quantum mechanics is at best irrelevant to the idealism v materialism debate, and at worse just invites obscurantism and confusion.

Take a look at the Kastrup thread - plenty of confusion and some obscurantism, doesn't help that QM purloined the term "observer".
Anyway, I'm interested in what you say about proving idealism by analysing perception - have you read John Foster? He attempts to argue for idealism entirely indepentently of the usual kind of arguments from illusion and hallucination.
By the way, any relation between you and MetaphyicsNow.com, or is that just coincidence ?

Quoting LD Saunders

An observation can occur without any conscious or living being present.

How so? If a spacecraft hurtles out past Neptune, all instruments intact, busily registering lots of data which will never be transmitted to Earth, does any of that amount to 'an observation'? It would seem not, according to the definition. (It is true that the Wikipedia definition says that 'In science, observation can also involve the recording of data via the use of scientific instruments' however, scientific instruments are explicitly created by scientists to capture data for observation, so whether the registration of data by an instrument amounts to an observation is still, I think, moot.)

Quoting LD Saunders

For one thing, since Einstein came up with relativity, and even before then regarding transforms, we can't even say that we are "observing" the moon any more than we can say that the moon is "observing" us, since space is not absolute. That should give anyone a hint that the discussion was not talking about consciousness being necessary in order for a material world exist.

So why do you think it was necessary for Einstein to raise the hypothetical question 'does the moon continue to exist when we're not looking at it?'

Quoting MetaphysicsNow

A materialist interpretation of quantum mechanics is possible, as is an idealist one.

Any examples?

Quoting MetaphysicsNow

Whether you can have Berkelian idealism without also requiring God to be around in the quad is an interesting question.

We definitely have posters who have argued for subjective idealism without utilizing God, even saying that God was the flaw in Berkley's philosophy.

Quoting MetaphysicsNow

dealing with issues concerning nominalism v realism about properties , personal identity over time, adverbialism and representationalsim in the philosophy of mind, to name just a few.

Sounds interesting. I've wondered if there is a way to resolve fundamental metaphysical disputes with that sort of approach where you bring in the various related issues and try to tie them all together.

Reply to Wayfarer

A materialist interpretation of quantum mechanics is possible, as is an idealist one. — MetaphysicsNow


Any examples?

For a materialist interpretation - Wheeler's "many worlds" comes to mind. The Von Neumann-Wigner interpretation is often cited as an idealistic one, but I've always suspected it of being more dualistic. For something more recent, you can take a look at
https://janszafranski.wordpress.com/2015/08/05/the-idealistic-interpretation-of-quantum-mechanics/
I think there's some philsophical confusion going on in the paper (to be expected of a scientist) but there's a theoretical physicist doing their best to formulate an idealistic interpretation.

Reply to Marchesk I don't think fundamental metaphysical disputes will ever be resolved :wink: Having said that, I share your opinion that you cannot even attempt to resolve them piecemeal - which is unfortunately the way that modern analytic philosophy tends to favour.

Reply to jkg20

Anyway, I'm interested in what you say about proving idealism by analysing perception - have you read John Foster? He attempts to argue for idealism entirely indepentently of the usual kind of arguments from illusion and hallucination.

I have heard of, but not read, Foster. As far as I am aware his basic argument is epistemological in nature, and the problem with that (at least insofar as analytic philosophy is concerned, a tradition to which he belongs) is that the standard position in analytic philosophy is that you cannot obtain a metaphysical conclusion from epistemological premises. In fact, that same principle is what causes the arguments from illusion and hallucination to be given pretty short shrift these days.

By the way, any relation between you and MetaphyicsNow.com, or is that just coincidence ?

Not a coincidence!

Reply to Marchesk

We definitely have posters who have argued for subjective idealism without utilizing God, even saying that God was the flaw in Berkley's philosophy.

As I see it, phenomenalistic/subjective idealism faces three challenges:
1) Avoid the collapse to solipsism
2) Account for the apparent permance of particulars
3) Account for the apparent fact that numerically distinct people can perceive one and the same thing in different ways (i.e. from different perspectives).

I'm not sure one can meet those challenges and remain an phenomenalist idealist without supposing there to be a God, but I'm also not sure you can even meet those challenges by supposing there to be a God.

Quoting MetaphysicsNow

Wheeler's "many worlds" comes to mind.

Wheeler did not originate the ‘Many worlds’ thesis. That was the work of his graduate student, Hugh Everett III - here- , although the term ‘many worlds’ was the work of a later researcher, Bryce DeWitt. Wheeler insisted that Everett tone down the thesis considerably, including removing all references to ‘splitting’. [As is explained in that article, Everett left academia disillusioned and instead worked for the military-industrial complex designing re-entry paths for ICBM warheads.]

The term ‘consciousness causes collapse’ has unfortunate connotations. Consciousness is not a ‘cause’ in the sense of a causal factor, on par with a spark causing an explosion. The reason that 'consciousness causes the collapse' is because:

'What answer we get depends on the question we put, the experiment we arrange, the registering device we choose'.

'Consciousness causes collapse' only in the sense that the performing of the measurement determines the kind of outcome. Of course the fact that an experiment produces an outcome is normally not an issue. The conundrum here is that, prior to this act of measurement, there is no particle, but only the probability of there being one; when the observation is made, hey presto! there's a particle. And in this case the object of this experiment is supposed to be a fundamental constituent of reality. So that's why it's a conundrum - and hence also Einstein’s question.

Reply to Wayfarer OK, but bear in mind that many worlds interpretations effectively deny that there is any such thing as the collapse of the wave equation at all. Materialist interpretations of QM will take issue with your statement

prior to this act of measurement, there is no particle, but only the probability of there being one

Under materialist interpretations there is always a particle, prior to, during and after measurement.

Reply to Edmund Thanks for putting me right about Knox, Edmund. I didn't do badly as a creative imitator thought, fair play!

Quoting MetaphysicsNow

Under materialist interpretations there is always a particle, prior to, during and after measurement.

I haven’t heard of any such interpretations. The many worlds interpretation doesn’t say that, but it’s not worth debating, as it can’t be resolved one way or the other.

Quoting MetaphysicsNow

As I see it, phenomenalistic/subjective idealism faces three challenges:
1) Avoid the collapse to solipsism
2) Account for the apparent permance of particulars
3) Account for the apparent fact that numerically distinct people can perceive one and the same thing in different ways (i.e. from different perspectives).

I hadn't thought of number two. Regarding #1, idealists had attempted to dismiss it with the claim that idealism includes other minds from the start. The problem there is epistemological. How do they know about the other minds? And that leads to a justification issue. You can't just define other minds into existence and call that good.

I've seen at least one hard core idealist admit that #3 was a challenge. I don't recall seeing mention of #2, but it's definitely an issue. I think there were claims that each perception was a separate particular, and there was no permanence. Problem being that we do perceive objects persisting.

Reply to Marchesk Regarding 1, granted it depends on how one argues for idealism, but simply to include other minds from the start smells of avoiding the difficult issues. Berkeley has a number of arguments, but if any of them are admitted as sound the metaphysical conclusion is at most that there is my mind and one other non-limited mind (to account for the fact that the world is recalcitrant to my will). Simply asserting that one's ontology includes other minds in that context is just to avoid the question, not to address it. A popular line of thought is the tu quoque response that materialist's have just as much of a problem as idealist's with establishing the existence of other minds.
With regard to 2, it is the apparent permanence of particulars (e.g. whenever I look into the clear night sky, I see the moon) that leads Berkeley to suppose that there must be a God that sustains the existence of the moon when no limited mind is looking at it. That may or may not work - God's perceptual relation to the moon probably has to be very different from ours when we look at it. More recent phenomenalists (some of the logical positivists for instance) tended to talk instead of "the moon" just being a term that ultimately unpacks as a set of conditional statements to the effect that "if person X were to look in direction y at time t, then person X would have an experience as of a moon being in the sky". The problem with this "moon as the permanent possibility of sensation" response is that it is natural to suppose that there is something that accounts for the truth of those conditional statements, and what is that something other than the continued existence of the moon when it is not being looked at?
As for (3), I think this is probably the most difficult issue for phenomenalistic idealism to address - I don't have much sensible to say about it at the moment, but it is something I am mulling over.

Reply to Wayfarer

I haven’t heard of any such interpretations. The many worlds interpretation doesn’t say that, but it’s not worth debating, as it can’t be resolved one way or the other.

The many world's interpretation is, at root, just the idea that the wave function quantifies over all actual and possible states of affairs, where those actual and possible states of affairs are ultimately actual and possible arrangements of electrons and other elementary particles. Hence it is fully committed to the existence of particles before after and during any experimental measurements. It denies any interpretation of QM that involves the idea that the wave function collapses at any point. It has an ontology (at least in many of its forms) that commits it to possibilia as well as actualities, but that might be the price to pay for maintaining materialism.
Anyway, as you say, this is not really the thread in which to discuss interpretations of QM.

Reply to MetaphysicsNow

Not a coincidence!

So when we will get this promised proof of God's existence then?

Quoting MetaphysicsNow

Hence it is fully committed to the existence of particles before after and during any experimental measurements.

I get that, but at the cost of there being many worlds. The MWI advocates here on this forum seem to obfuscate that inconvenient fact.

The question I always ask is: if you're prepared to entertain such a fantastic idea, then what problem are you actually solving? If indeed 'desperate problems call for desperate remedies' - then what's the problem? What do you have to admit, if you let go of MWI?

Reply to Wayfarer

I get that, but at the cost of there being many worlds.

True, but then for some people that is more palatable than idealism. Incidently, there was at least one recent philosopher (David Lewis, whose ideas are still quite influential in so-called analytic philosophy) who had a range of arguments independent of QM interpretation for the real existence of possible worlds. So even that issue is independent of the whole QM debate.

Quoting MetaphysicsNow

that is more palatable than idealism.

And then, the question is ‘why’. What is so unpalatable about the irreducible nature of mind? Why is that such a boogeyman? It seems to me an illustration of the incredible things people will be prepared to entertain, just to avoid the possibility that materialism might not be real. Not trying to argue the case, only for reflection on it.

Quoting Wayfarer

And then, the question is ‘why’. What is so unpalatable about the irreducible nature of mind? Why is that such a boogeyman? It seems to me an illustration of the incredible things people will be prepared to entertain, just to avoid the possibility that materialism might not be real. Not trying to argue the case, only for reflection on it.

I think it just comes down to one's fundamental philosophy, especially one's position on universals.

It seems to me that you start with mind (a universal) and your ontology follows from that. What seems incredible to you, and yet seems reasonable to a materialist, is just a function of where one starts from. For a materialist, quantum mysticism seems incredible.

Reply to Andrew M I agree. But I think that the Platonist insight into the reality of incorporeal entities (universals and the like) requires a genuine meta-cognitive shift - a gestalt shift, if you like.

Years ago, there were books published with 'magic eye' puzzles in them. They looked just like completely random patterns of colours and shapes until you held them in a particular way at an arm's length from your eyes, then suddenly an image would come into focus.

Apparently, anyway. I never saw it. ;-)

Quoting Wayfarer

But I think that the Platonist insight into the reality of incorporeal entities (universals and the like) requires a genuine meta-cognitive shift - a gestalt shift, if you like.

True, but genuine cognitive shifts don't have to end there. As you know, Aristotle was well-versed in Plato's ideas and his hylomorphism retained universals sans the Platonic reification.

Aristotle's position stands in contrast to both Platonic idealism and Democretean materialism. An Hegelian synthesis perhaps.

Reply to Andrew M I'd be interested in your take on this blog post; I myself find it quite persuasive, and it is said to be written from the perspective of Aristotelianism.

Reply to Wayfarer Yes I agree with the blog post - I think the basic argument boils down to both form and matter being indispensable categories that aren't reducible to the other.

So materialism fails when it eliminates form and idealism fails when it eliminates matter. Hence hylomorphism.

Reply to Andrew M :ok: